Environmental Benefits of Tree
Trees alter the environment in which we live by moderating climate,
improving air quality, conserving water, and harboring wildlife. Climate
control is obtained by moderating the effects of sun, wind, and rain.
Radiant energy from the sun is absorbed or deflected by leaves on
deciduous trees in the summer and is only filtered by branches of
deciduous trees in winter. We are cooler when we stand in the shade of
trees and are not exposed to direct sunlight. In winter, we value the sun
radiant energy. Therefore, we should plant only small or deciduous trees
on the south side of homes.
Wind speed and direction can be affected by trees. The more compact
the foliage on the tree or group of trees, the greater the influence of the
windbreak. The downward fall of rain, sleet, and hail is initially absorbed
or deflected by trees, which provides some protection for people, pets,
and buildings. Trees intercept water, store some of it, and reduce storm
runoff and the possibility of flooding.
Dew and frost are less common under trees because less radiant energy
is released from the soil in those areas at night.
Temperature in the vicinity of trees is cooler than that away from trees.
The larger the tree, the greater the cooling. By using trees in the cities,
we are able to moderate the heat-island effect caused by pavement and
buildings in commercial areas.
Air quality can be improved through the use of trees, shrubs, and turf.
Leaves filter the air we breathe by removing dust and other particulates.
Rain then washes the pollutants to the ground. Leaves absorb carbon
dioxide from the air to form carbohydrates that are used in the plant
structure and function. In this process, leaves also absorb other air
pollutants such as ozone, carbon monoxide, and sulfur dioxide and give
By planting trees and shrubs, we return to a more natural, less artificial
environment. Birds and other wildlife are attracted to the area. The
natural cycles of plant growth, reproduction, and decomposition are
again present, both above and below ground. Natural harmony is
restored to the urban environment.
10 Best Trees You Should Plant
Consider Planting These Trees in Your Yard
By Steve Nix, About.com Guide
I've reviewed the popular literature for you, polled my About Forestry
forum and the Internet for the most popular trees and compiled these
frequently requested trees to use as a starting place. By further studying
the commercial appeal of each of these individual species and taking into
account horticulturists' praise I selected my ten best.
No Tree Is Perfect
Remember, all yard trees have good and bad characteristics. It is a rare
tree that will satisfy your needs throughout its entire life span. A tree can
outgrow its original purpose very quickly or grow into its intended
purpose very slowly. Understanding this concept is the key to proper tree
planting in your yard.
Tree Roots Effects on Soil
Full of benefits, trees have an enviable position in any landscape, shade,
controlling soil erosion, home to many birds, fruits and flowers. Of all
the parts of a tree, the roots are perhaps the most unappreciated, as they
There are two types of roots; primary roots that grow deep down
vertically into the soil and secondary roots that branch out horizontally.
The architecture of the root system is to absorb water and inorganic
nutrients and anchor the plant to the ground.
The roots affect the soil, depending on the type of the tree and the soil.
These effects have a direct impact on all the plants grown near the tree.
Normally a healthy tree represents healthy soil. A big tree takes up most
of the water available in the soil, leaving the other plants dry. Growing as
well as mowing lawn grass is another difficulty around a large tree,
especially if the roots are protruding outside. Tree roots help control soil
erosion, however in some cases the roots have a negative effect on the
soil by causing a phenomenon called allelopathy.
Derived from two words; allelonwhich means of each other and pathos
which means to suffer. It refers to the chemical inhibition of one species
by another, by releasing a chemical affecting the development and
growth of surrounding plants. In other words, plants try to get their own
space, by restricting other plants from growing too close to them.
Allelopathic chemicals secretion are not just restricted to the roots, they
are also found in branches, leaves, flowers and fruits. The decomposed
leaves and bark affect the top layer of soil, while the roots affect the
surrounding soil. The chemical curtails the root growth of other plants
by inhibiting their nutrient source, thus influencing their evolution and
It is an aromatic organic allelopathic compound occurring naturally in the roots,
bark and leaves of trees in the Juglandaceae family. It releases certain enzymes that
inhibits the metabolic function, stunting the growth of many plants and at times
even killing an allelopathy intolerant plant. The quantity of Juglone released
depends on the weather and soil conditions. The black walnut is the most commonly
known for its allelopathic properties. When Juglone sensitive plants come within 0.5 4
to 0.25 inches of the tree roots, they turn yellow, wilt and die. This in turn, also
infects the soil.
The Original Multi-taskers
• Provide social, ecological, and economic benefits
• Their beauty inspires writers and other artists.
• Their leaves and roots clean the air we breathe and the water
Top 10 Reasons Why Trees Are Valuable and Important
Trees are important, valuable and necessary to our very existence. It's
not too hard to believe that, without trees we humans would not exist on
this beautiful planet.
In fact, some claim can be made that our mother's and father's ancestors
climbed trees - another debate for another site.
Still, trees are essential to life as we know it and are the ground troops
on an environmental frontline.
Our existing forest and the trees we plant work in tandem to make a
better world. 5
Studi Pengaruh Kualitas Vegetasi pada Lingkungan Termal
Kawasan Kota di Bandung Menggunakan Data Citra Satelit
Surjamanto Wonorahardjo, Suwardi Tedja, Benedictus Edward
Laboratorium Teknologi Bangunan
Sekolah Arsitektur, Perencanaan dan Pengembangan Kebijakan
Institut Teknologi Bandung
E-mail : firstname.lastname@example.org
Tulisan ini membahas lingkungan termal kawasan perkotaan yang
dipengaruhi oleh berbagai aspek antara lain bentuk permukaan kawasan,
kepadatan dan penggunaan bahan bangunan. Salah satu aspek fisik
permukan kawasan yang diyakini para ahli dapat mempengaruhi suhu
udara adalah vegetasi seperti taman kota, pohon di tepi jalan dll.
Konsep zoning pada kota membentuk kawasan dengan keunikan
karakteristik fisik permukaan dan vegetasinya sehingga membentuk
kenikan lingkungan termal seperti terbentuknya pulau-pulau panas (heat
Penelitian ini memanfaatkan data satelit Landsat ETM yang mengambil
citranya dalam 7 band termasuk di dalamnya citra termal. Metoda ini cukup
akurat karena citra (termal) satelit mempunyai resolusi 1 pixel = 60mx 60 m.
Pendataan suhu udara lingkungan juga dilakukan dengan pengukuran
lapangan untuk pembanding data citra satelit tersebut.
Analisis dilakukan terhadap pengaruh tipe vegetasi (pohon, perdu, rumput
di lahan terbuka dll) terhadap fisik permukaan kawasan (bentuk permukaan
kawasan, kepadatan, penggunaan bahan bangunan) dari aspek
pembentukan lingkungan termalnya. Hasil penelitian menunjukkan
lingkungan termal kawasan kota sangat dipengaruhi oleh karakteristik
Manfaat pohon di perkotaan
• Save Energy
• Improve air quality
• Extend life of paved surfaces
• Increase traffic safety
• Increase real estate values
• Increase sociological benefits
• Protect our water resources
1. Trees Produce Oxygen
Let's face it, we could not exist as we do if there were no trees. A
mature leafy tree produces as much oxygen in a season as 10 people
inhale in a year. What many people don't realize is the forest also acts
as a giant filter that cleans the air we breath.
Air hujan dan Siklus Hidrologi
• Urbanization dramatically alters the hydrologic cycle
– Increases runoff
– Increases flooding frequency
– Decreases infiltration and groundwater recharge
• Nationwide impervious surfaces have increased by 20% in
the past 20 years
Effect of vibrations of tree roots on soil permeability.
Danilik, V. N., Makarenko, G. P., Tolkach, O. V.
Ural'skaya Lesnaya Opytnaya Stantsiya, VNIILM, Russia.
Measurements were made in the Urals of the wind-induced movements of 33 roots
of Scots pine [Pinus sylvestris] and Norway spruce [Picea abies] trees, and of the
effect of these root movements on soil permeability.
Details are given of the procedure; measurements were made when the amplitude
of crown tip swaying was 1.4-3.0 m, which corresponded to a strong wind of 11-13
m/s. Root movement occurred in the vertical and the horizontal planes, both
perpendicularly and along the root.
The amplitude of the root vibrations depended on the structure of the root system,
soil mechanical composition, distance from the stem, amplitude of stem sway, and
The greatest vibrations (0.05-1.11 mm) were those vertical and horizontal across the
roots, but they rapidly decreased with increasing distance from the stem. Wind-
sway of the stems, leading to vibration of the roots and the ball of soil, increased
water permeability along the roots on average by a factor of 3.7, and of the soil
within the root system by a factor of 1.2-1.9. Swaying trees accelerated the
movement of water along the vibrating roots much more on light than on heavy
Journal of Arboriculture
Fill soil effects on soil aeration and tree growth.
MacDonald, J. D., Costello, L. R., Lichter, J. M., Quickert, D.
Department of Plant Pathology, University of California, Davis, One
Shields Avenue, Davis, CA 95616, USA.
A 4-year study was conducted to evaluate the effects of fill soil on tree
growth and soil aeration. Cherry trees (Prunus × yedoensis 'Afterglow')
were grown for 3 years in a test plot in Davis, California, U.S., after which
the block of trees was divided into three subplots. In one subplot, 30 cm
(12 in.) of compacted fill soil was installed over the root zone, while in a
second subplot, aeration piping was installed prior to fill installation.
A third subplot was left without fill (control). Oxygen diffusion rate (ODR)
and moisture levels were measured in the base soil before and after
addition of fill.
Trunk diameter was measured at fill installation and 1 year later, while
stem water potential was measured after 1 year. Fill soil neither reduced
soil aeration levels nor had a negative impact on tree growth. Tree growth
in fill subplots was equivalent to or greater than controls. Aeration piping
did not enhance oxygen diffusion rates in the underlying field soil.
Roots developed in the fill but did not grow preferentially around aeration
pipes. Although aeration deficit may play a role in fill-induced plant injury,
other factors may play an equal or greater role. These factors include soil
compaction and root injury during fill installation, and water deficit
following fill installation. All factors should be considered in pre- and
post-fill tree management plans. 9
How Do We Know That Trees Improve Soils?
Underlying all aspects of the role of agroforestry in maintenance of soil
fertility is the fundamental proposition that trees improve soils. How we
know that this is true?
1. The soil that develops under natural forest and woodland is fertile. It is
well structured, has a good water-holding capacity and has a store of
nutrients bound up in the organic matter. Farmers know they will get a
good crop by planting on cleared natural forest.
2. The cycles of carbon and nutrients under natural forest ecosystems
are relatively closed, with much recycling and low inputs and outputs.
3. The practice of shifting cultivation demonstrated the power of trees to
restore fertility lost during cropping.
4. Experience of reclamation forestry has demonstrated the power of10
trees to build up fertility on degraded land.
Acta Phytoecologica Sinica
Modeling canopy rainfall interception in the upper watershed of the
Li ChongWei, Liu ShiRong, Sun PengSen, Zhang YuanDong, Ge JianPing
College of Life Sciences, Beijing Normal University, Beijing 100875, China.
The headwaters of the Minjiang River are on the eastern edge of the Tibetan plateau.
Canopy rainfall interception plays an important role in the water balance at the
Many studies on canopy rainfall interception have been carried out at the stand level
but less effort has been devoted towards understanding canopy interception at large
scale, neither in the Minjiang River basin nor other areas. In this study, modeling
canopy rainfall interception in subalpine forests and meadows in the upper reaches
of the Minjiang River was carried out by using field surveys, MODIS data, and RS,
GPS and GIS technologies.
LAI (leaf area index), vegetation cover and canopy capacity per unit leaf area were
the main parameters used in the model. LAI was derived from the vegetation index
and measured using a LAI-2000 in the forests and LAI-3000 in the sub-alpine
meadows. The LAI of coniferous stands were multiplied by a correction factor
because of the clumped arrangement of needles in the crown. Normalized difference
vegetation index (NDVI) and enhanced vegetation index (EVI) were composed by
red, near-infrared and blue reflectances from the 500 m 32-day composites available
from the MODIS level 3 surface reflectance (MOD09A1).
The results indicated that LAI was non-linearly correlated to NDVI and EVI. EVI was
preferable to NDVI as NDVI saturates in well-vegetated areas and the degree of
correlation between LAI and EVI is higher than that between LAI and NDVI. The
results showed that the LAI of vegetation in the upper reaches of the Minjiang River
were in the following categories: 28.57% between 0 and 2, 63.06% between 2 and 4.5,
and 8.37% above 4.5.
LAI was estimated using EVI, and the results showed that LAI could better reflect the
spatial distribution of the vegetation. LAI in the upper watershed was lower than
down river due to a large number of trees in the down river. Vegetation cover was
derived from NDVI. The spatial distribution of canopy capacity per unit leaf area was
modeled on the basis of a vegetation-classification map (1:1000000).
Canopy rainfall interception in the well-vegetated areas was higher than that in other
The model was validated using field measurements made in Wolong and Miyaluo
and some additional sites in the upper watershed of the Minjiang River. Empirical
expressions to describe evaporation from the wet canopy were derived from
additional sites and evaporation from the wet canopy was closely correlated to
Based on the empirical expressions, simulation results showed that there was a 15.4
percent error in Wolong and a 19.4 percent error in Miyaluo
Semakin banyak pohon, semakin sedikit limpasan
permukaan air hujan
Fayetteville, Arkansas: increasing tree canopy from 27-40%
reduced their storm water runoff by 31%
South Miami residential study found that a 21% existing tree
canopy reduces the storm water runoff by 15%
For every 5% of tree cover added to a community, storm
water is reduced by approximately 2%
Communal Benefits of tree
Even though trees may be private property, their size
often makes them part of the community as well.
Because trees occupy considerable space, planning is
required if both you and your neighbors are to benefit.
With proper selection and maintenance, trees can
enhance and function on one property without infringing
on the rights and privileges of neighbors.
City trees often serve several architectural and
engineering functions. They provide privacy, emphasize
views, or screen out objectionable views. They reduce
glare and reflection. They direct pedestrian traffic. They
provide background to and soften, complement, or
Pergerakan air hujan di dalam profil tanah
2. Trees Clean the Soil
The term phytoremediation is a fancy word for the absorption of
dangerous chemicals and other pollutants that have entered the soil.
Trees can either store harmful pollutants or actually change the
pollutant into less harmful forms.
Trees filter sewage and farm chemicals, reduce the effects of animal
wastes, clean roadside spills and clean water runoff into streams.
Bagaimana pohon mempengaruhi air hujan ?
• Above ground effects:
– Interception, evaporation and absorption of
• Ground surface effects:
– Temporary storage
• Below ground effects:
– Infiltration, permeation and filtration
Journal of the Indian Society of Soil Science
Impact of growing trees/grasses on physical properties of a saline soil.
Nandagoudar, S. A., Patil, S. G., Manjunatha, M. V., Hebbara, M., Gupta, R. K.,
Minhas, P. S.
AICRP on Management of Salt-affected Soils and Use of Saline Water in Agriculture,
Agricultural Research Station, Gangawati, Karnataka 583 227, India.
A field experiment was conducted at Agricultural Research Station,
Gangawati, Karnataka, India, to study the effect of tree species alone or
in combination with grasses on physical properties of a saline soil.
Six tree species viz. Casuarina equisetifolia, Acacia nilotica, Dalbergia
sissoo, Azadirachta indica, Sesbania grandiflora and Hardwickia binata
and napier grass (Pennisetum purpureum) were planted in 1991 and
physical properties were determined during 1995-96.
Due to the improvement in soil organic carbon, physical characteristics
such as porosity, infiltration rate, hydraulic conductivity and aggregate
stability improved under different tree covers, while, bulk density and
erodibility of soil decreased.
Acacia nilotica and Casuarina equisetifolia had higher influence on these
bio-physical properties than the other species. Grasses when planted
with trees had complementary effect
Hydrological Sciences Journal
Measurement of rainfall interception by xerophytic shrubs in re-vegetated
Wang XinPing, Li XinRong, Zhang JingGuang, Zhang ZhiShan, Berndtsson, R.
Shapotou Desert Experimental Research Station, Cold and Arid Regions
Environmental and Engineering Research Institute, Chinese Academy of Sciences,
260 Donggang West Road, Lanzhou 730000, China.
More than 40 years of re-vegetation using mainly xerophytic shrubs
Artemisia ordosica Krasch. and Caragana korshinskii Kom. at Shapotou
Desert Experimental Research Station near Lanzhou, China has resulted
in established dwarf-shrub and herbaceous cover on sand dunes.
Precipitation, as the sole source of water replenishment in the semiarid
area, plays a pertinent role in sustaining the desert ecosystem.
A field study was conducted to (a) measure interception loss on shrub
canopies during individual rainfall events, (b) determine the canopy
storage capacity of individual plants, and (c) explore the relationship
between interception and rainfall parameters.
The total rainfall and its respective partitions as throughfall were
determined and the interception losses in the studied ecosystem were
quantified. Interception loss was shown to differ among the xerophyte
taxa studied. During the growing seasons, the average shrub community
interception loss is 6.9% and 11.7% of the simultaneous overall
precipitation, for A. ordosica and C. korshinskii, respectively. Taking into
account the observed rainfall conditions and vegetation cover
characteristics, it was concluded that the interception loss was 2.7% of
the total annual precipitation verified in the period for the A. ordosica
community with an average cover of 30%, canopy projection area of 0.8
m2 and canopy storage capacity of 0.75 mm.
In contrast, interception loss for the C. korshinskii community was 3.8%
with an average cover of 46%, canopy projection area of 3.8 m2 and
canopy storage capacity of 0.71 mm.
For individual plants of both shrubs, the proportion of interception loss to
gross rainfall decreased notably as the rainfall intensity increased
between 0 and 2 mm h-1, while it tended to remain constant at about 0.1-
0.2 for A. ordosica and 0.1-0.3 for C. korshinskii when the rainfall
intensity was >2 mm h-1.
Food production, poverty alleviation and environmental challenges as
influenced by limited water resources and population growth. Volume
1A. 18th International Congress on Irrigation and Drainage, Montréal,
Towards improving of water management in fruit-tree
plantations under micro-irrigation.
Koumanov, K. S.
Nat.Cent. Agric.Sci., Inst.Fruit Growing, 12 Ostromila, Plovdiv 4004, Bulgaria.
Precise water balance under micro-sprinkling and drip irrigation of fruit
trees showed that the application efficiency was strongly dependent on
both the climatic conditions and the soil hydraulic properties.
Root activity affected irrigation water redistribution, creating zones with
low soil moisture values (down to wilting point) along the skeletal roots
very soon (20 hours) after the irrigation. Under drip irrigation, soil
moisture in the remaining part of the bulb was still close to field capacity
but roots were not able to access it.
When the wetted soil volume was larger, as under micro-sprinkler
irrigation, root water uptake was found to be, spatially and temporarily,
very dynamic. Hence, crop water use efficiency would be increased if
irrigation strategy was based on physical models of evaporation from
partially wetted soil surface, irrigation water redistribution in the soil,
and root water uptake.
Microsprinkling was found to affect positively microclimate in fruit-tree
plantations, decreasing air temperatures and increasing significantly air
This effect was more pronounced in dry and hot conditions. The
experiments were carried out in peach and almond plantations on
various soil types carried out in Bulgaria and California, USA
3. Trees Control Noise Pollution
Trees muffle urban noise almost as effectively as stone walls.
Trees, planted at strategic points in a neighborhood or around
your house, can abate major noises from freeways and airports.
4. Trees Slow Storm Water Runoff
Flash flooding can be dramatically reduced by a forest or by
planting trees. One Colorado blue spruce, either planted or
growing wild, can intercept more than 1000 gallons of water
annually when fully grown.
Underground water-holding aquifers are recharged with this 18
slowing down of water runoff
Pengaruh di atas permukaan tanah
• Intercept rainwater on leaves, branches and trunks –
slowing its movement
• Evaporation of some of this intercepted precipitation of
the tree surfaces
• Absorption of a small portion into leaves or stems
Vegetation effects on soil and water losses on weathered granitic
hillslopes, South China.
Woo, M. K., Luk, S. H.
Dep. Geography, McMaster Univ., Hamilton, Ont. L8S 4K1, Canada.
Deforestation of weathered granitic hillslopes of South China (Guangdong
Province) has led to widespread erosion.
Using small experimental plots under different vegetation cover, the
effects of land use on soil and water losses were examined.
Overland flow increased as the cover conditions changed from forest to
fern, to tilled soil and, eventually, to bare ground. This is related to the
amount of interception and infiltration, both of which decreased as the
vegetation cover decreased. Most slopes consist of a combination of
loose materials and weathered granite and the resistance to sediment
entrainment could not be easily determined.
The potential sediment yield increased as vegetation cover decreased.
Based on empirical relationships between rainfall, overland flow and
potential sediment yield, it is demonstrated that soil and water losses can
be greatly reduced as vegetation is re-established on these denuded
Ground Surface Effects
• Leaf litter and other organic matter can hold precipitation and
stemflow on a site, reducing the amount and peak rates of runoff
• Roots and trunk bases of mature trees tend to create hollows and
hummocks on the ground
Below Ground Effects
• Organic material from leaf litter and other tree detritus tends to
increase infiltration rates by increasing pore spaces in soil
• Organic material also increases the moisture-holding capacity of
• Root mats of trees also tend to break up most soils further
improving infiltration and moisture-holding capacity
Indian Journal of Agroforestry
Effect of soil depth on early performance and characteristics of roots of
some tree species on a hill slope.
Singh, K. A.
ICAR Research Complex for Eastern Region, Barapani (Meghalaya) - 793 103, India.
A field experiment was conducted in Meghalaya, India, to determine the effects of soil
depths on root characteristics and biomass productivity of four tree species (Pinus
kesiya, Michelia champaca, Grevillea robusta and Cupressus torulosa) planted on a
Changes in root characteristics revealed that vertical penetration of main root,
number of roots and root weight per plant increased in proportion to soil depth
occupied by the tree species. The main root changed its course of orientation
sensing impediments and moved down the hill slope. Mean root spread decreased
significantly in the deep soil in case of M. champaca and P. kesiya but it increased
marginally in case of G. robusta and C. torulosa as compared to shallow soils.
Broadleaved M. champaca and G. robusta had reduced root length, thicker proximal
diameter of main and lateral roots in shallow soils while in pine group of plants,
either length of main root was shorter in deep soil than the shallow soil as in case of
P. kesiya or there was no significant difference in root length as in case of C.
torulosa, both the tree species also grew thicker roots in the deep soils. Effect of soil
depth on plant growth became evident 18 months after planting.
The differential behaviour of tree species in response to soil depths indicated their
adaptation and success on the hill slopes through changes in root characteristics
particularly root spread and modification in different parts of shoot i.e., basal and
breast height diameters, number of branches per plant, canopy length in case of
broadleaved tree species and canopy length and canopy diameter both in case of
pine group of tree species.
Thus, the little difference in root number under different soil depths and tendency to
spread extensively under shallow soil depth leading to minimal variation in total
biomass productivity helped P. kesiya to be most adaptive on the shallow soils of the
hill slopes followed by M. champaca, a broadleaved tree species
Nutrient Cycling in Agroecosystems
Shade tree effects in an 8-year-old cocoa agroforestry system: biomass
and nutrient diagnosis of Theobroma cacao by vector analysis.
Isaac, M. E., Timmer, V. R., Quashie-Sam, S. J.
Faculty of Forestry, University of Toronto, 33 Willcocks St., Earth Science Centre,
Toronto, M5S 3B3, Canada.
Farm product diversification, shade provision and low access to fertilizers
often result in the purposeful integration of upper canopy trees in cocoa
(Theobroma cacao) plantations. Subsequent modification to light and soil
conditions presumably affects nutrient availability and cocoa tree
nutrition. However, the level of complementarity between species requires
investigation to minimize interspecific competition and improve resource
We hypothesized beneficial effects of upper canopy trees on cocoa
biomass, light regulation, soil fertility and nutrient uptake. We measured
cocoa standing biomass and soil nutrient stocks under no shade
(monoculture) and under three structurally and functionally distinct shade
trees: Albizia zygia (D.C.) Macbr, a nitrogen fixer; Milicia excelsa (Welw.), a
native timber species; and Newbouldia laevis (Seem.), a native small
stature species. Vector analysis was employed to diagnosis tree nutrition.
Cocoa biomass was higher under shade (22.8 for sole cocoa versus 41.1
Mg ha-1 for cocoa under Milicia), and declined along a spatial gradient
from the shade tree (P<0.05). Percent canopy openness differed between
the three shade species (P=0.0136), although light infiltration was within
the optimal range for cocoa production under all three species.
Soil exchangeable K was increased under Newbouldia, while available P
decreased and total N status was unaffected under all shade treatments.
Nutrient uptake by cocoa increased under shade (43-80% and 22-45% for
N and P, respectively), with K (96-140%) as the most responsive nutrient in
these multistrata systems.
Addition of low-density shade trees positively affected cocoa biomass
close to the shade tree, however proper management of upper stratum
trees is required for optimum cocoa productivity and sustainability
Below Ground Effects
• Deep roots tend to improve the rates of percolation of water from
upper soil horizons into lower substrates
• Trees take up water through their roots that is eventually
transpired onto leaf surfaces and evaporated
• Tree roots act as natural pollution filters (biofilters) using nitrogen,
phosphorus and potassium.
Pattern of root distribution in 30-month old five tree and two shrub
species of an arid region of north-western India.
Virendra Singh, Rajbahadur, Hooda, M. S., Balkrishan
Department of Agroforestry, Chaudhary Charan Singh Haryana Agricultural
University, Hisar, Haryana, India.
Structure and distribution of root systems were studied in 30-month old
trees of 5 species (Acacia nilotica, Leucaena leucocephala, Dalbergia
sissoo, Azadirachta indica and Prosopis cineraria) and 2 shrub species
(Prosopis juliflora and Cajanus cajan) raised at a spacing of 4×0.5 m at
Maximum penetration of root systems was observed in P. cineraria (138
cm depth), followed by Acacia nilotica, D. sissoo, L. leucocephala and P.
juliflora, while Azadirachta indica and C. cajan showed comparatively
shallow root systems (85 and 65 cm depth, respectively). P. juliflora
showed the maximum root spread (347 cm), followed by L. leucocephala
(228 cm), Acacia nilotica (216 cm), D. sissoo (187 cm), Azadirachta indica
(95 cm), C. cajan (80 cm) and P. cineraria (31 cm). The top 30 cm of soil
had the maximum distribution of root biomass in C. cajan, Azadirachta
indica and L. leucocephala (45-62% of the total), whereas the maximum
distribution of root biomass in P. juliflora, Acacia nilotica and D. sissoo
(34-40% of the total) was in the top 30-60 cm of soil.
Root distribution in P. cineraria was almost uniform throughout the soil
column. The superficial location of a high proportion of roots in stands
of C. cajan, Azadirachta indica and L. leucocephala indicates that these
species will show strong root competition if intercropped with crops, in
comparison with Acacia nilotica, D. sissoo and P. juliflora in which most
of the roots had a subsurface location. A vertical root system and narrow 23
crown in P. cineraria make this species the most suitable for
5. Trees Are Carbon Sinks
To produce its food, a tree absorbs and locks away carbon
dioxide in the wood, roots and leaves. Carbon dioxide is a
global warming suspect. A forest is a carbon storage area or a
"sink" that can lock up as much carbon as it produces. This
locking-up process "stores" carbon as wood and not as an
available "greenhouse" gas.
EPA‘s Tree Canopy Target Goals
• Set to protect a community‘s green infrastructure and
maximize the environmental benefits
• For metropolitan areas east of the Mississippi
– Average tree cover for all land use 40%
– Suburban residential 50%
– Urban residential 25%
– Central business districts 15%
What Makes a Good Soil Improving Tree?
It would be useful to have guidelines on which properties of a tree or
shrub species make it desirable for the point of view of soil fertility.
This would help in identifying naturally occurring species and
selecting trees for systems which have soil improvement as a specific
Nitrogen fixation and a high biomass production have been widely
recognized as desirable. However, many properties are specific to
particular objectives of systems in which the trees are used. Even
species that are shunned for their competitive effects may have a role
in certain designs.
An example is the way in which Eucalyptus species with a high water
uptake, which adversely affects yields in adjacent crops, have been
employed to lower the water table and so reduce salinization.
6. Trees Clean the Air
Trees help cleanse the air by intercepting airborne particles,
reducing heat, and absorbing such pollutants as carbon
monoxide, sulfur dioxide, and nitrogen dioxide.
Trees remove this air pollution by lowering air temperature,
through respiration, and by retaining particulates.
SIKLUS ENERGI 26
• Presence of soil compaction
• Presence of soil textural discontinuity
– Has the site been disturbed in the past?
• Management of the ground surface
– Is litter layer removed?
– Is soil surface exposed in winter?
– How much of the surface is like a natural forest? (number
and size of trees)
The properties which are likely to make a woody perennial suitable for
soil fertility maintenance or improvement are:
1. A high rate of production of leafy biomass.
2. A dense network of fine roots, with a capacity for abundant
3. The existence of deep roots.
4. A high rate of nitrogen fixation.
5. A high and balanced nutrient content in the foliage; litter of high
quality (high in nitrogen, low in lignin and polyphenols).
6. An appreciable nutrient content in the root system.
7. Either rapid litter decay, where nutrient release is desired, or a
moderate rate of litter decay, where maintenance of a soil cover is
8. Absence of toxic substances in the litter or root residues.
9. For soil reclamation, a capacity to grow on poor soils.
10. Absence of severe competitive effects with crops, particularly for
11. Low invasiveness.
12. Productive functions, or service functions other than soil
Pergerakan air dalam tanah
Forces affecting the energy of soil water
Matric force (absorption and capillary)
Pergerakan air dalam tanah
• Field Capacity is the amount of water held in the soil after
gravitational water had drained away
• Movement of water is the soil is controlled :
– Gravitational forces if saturated
– Matric forces if unsaturated
7. Trees Shade and Cool
Shade resulting in cooling is what a tree is best known for. Shade
from trees reduces the need for air conditioning in summer. In
winter, trees break the force of winter winds, lowering heating costs.
Studies have shown that parts of cities without cooling shade from 29
trees can literally be "heat islands" with temperatures as much as 12
degrees Fahrenheit higher than surrounding areas.
Soil Factors Influencing Infiltration
• Infiltration is the mode of entry of all water into the soil
• Rate of infiltration determined:
– Initial water content
– Surface permeability
– Internal characteristics of the soil
• Intensity and duration of rainfall
• Temperature of soil and water
8. Trees Act as Windbreaks
During windy and cold seasons, trees located on the windward
side act as windbreaks. A windbreak can lower home heating
bills up to 30% and have a significant effect on reducing snow
drifts. A reduction in wind can also reduce the drying effect on
soil and vegetation behind the windbreak and help keep 30
precious topsoil in place.
Soil Factors Influencing Infiltration
• Soil compaction reduces the infiltration rate
• Microrelief under trees provides catchment basins during heavy rains
• Removal of litter layer reduces the infiltration rate
9. Trees Fight Soil Erosion
Erosion control has always started with tree and grass planting
projects. Tree roots bind the soil and their leaves break the
force of wind and rain on soil.
Trees fight soil erosion, conserve rainwater and reduce water
runoff and sediment deposit after storms.
Soil Factors Influencing Infiltration cont.
Forest soils have a high percentage of macropores
The frost type found in forest soils promotes infiltration year-long
10. Trees Increase Property Values
Real estate values increase when trees beautify a property or
neighborhood. Trees can increase the property value of your home by
15% or more.
Importance of the Litter Layer
Absorbs several times its own weight
Breaks the impact of raindrops
Prevents agitation of the mineral soil
Discourages formation of surface crusts
Forest Ecology and Management
Spatial distribution of root length density and soil water of linear
agroforestry systems in sub-humid Kenya: implications for agroforestry
Radersma, S., Ong, C. K.
Department of Soil Quality, Agricultural University, P.O. Box 8005, 6700 EC
IN SIMULTANEOUS AGROFORESTRY SYSTEMS TREES CAN COMPETE WITH CROPS
FOR WATER, ESPECIALLY IN SEMI-ARID AREAS. HOWEVER, IN THE (SUB)HUMID
TROPICS, ON P-FIXING OXISOLS/FERRALSOLS SMALL DECREASES IN SOIL WATER
CONTENT CAUSED A DECREASE IN P-TRANSPORT TO ROOTS AND THEREWITH A
SOIL-DRYING INDUCED P-DEFICIENCY. THE AIM OF THIS STUDY WAS TO ASSESS
THE SPATIAL DISTRIBUTION OF SOIL WATER CONTENT IN CROP FIELDS
BORDERING TREE LINES AND ITS RELATION WITH ROOT LENGTH DENSITY
DISTRIBUTION OF THE TREES THROUGHOUT THE SOIL PROFILE. TO ACHIEVE THIS,
SOIL WATER CONTENT AND TREE ROOT LENGTH DENSITIES THROUGHOUT THE
SOIL PROFILE WERE MEASURED OVER A PERIOD OF 2 YEARS IN AN EXPERIMENT
WITH LINES OF FOUR TREE SPECIES IN THE MIDDLE OF MAIZE FIELDS IN SUB-
HUMID WESTERN KENYA. SOIL WATER CONTENT WAS SIGNIFICANTLY REDUCED (2-
7 VOL.%) NEAR TWO OF THE THREE FAST-GROWING TREE SPECIES, EUCALYPTUS
GRANDIS AND GREVILLEA ROBUSTA, BUT NOT NEAR CEDRELLA SERRATA AND
THE SLOWER GROWING MARKHAMIA LUTEA. THESE DIFFERENCES WERE
RELATED TO DIFFERENCES IN WATER USE. EUCALYPTUS AND GREVILLEA
SHOWED HIGH WATER USE AND CEDRELLA AND MARKHAMIA LOW WATER USE.
HOWEVER, SOIL WATER CONTENT DISTRIBUTION WAS NOT RELATED TO ROOT
LENGTH DENSITY DISTRIBUTION. ROOT LENGTH DENSITIES HARDLY DECREASED
WITH DISTANCE TO GREVILLEA AND CLEARLY DECREASED WITH DISTANCE TO
CEDRELLA. MOST WATER-UPTAKE MODELS, INCLUDING THOSE OF
AGROFORESTRY MODELS, ASSUME THAT ROOT LENGTH DENSITY DISTRIBUTION
THROUGHOUT THE PROFILE IS PROPORTIONAL TO WATER EXTRACTION
THROUGHOUT THE PROFILE.
THE ABSENCE OF A CLEAR RELATION BETWEEN ROOT LENGTH DENSITY AND
WATER EXTRACTION NEAR GREVILLEA TREE LINES OPPOSED THIS VIEW. IT CAN
BE EXPLAINED BY A DECREASE IN WATER-POTENTIAL GRADIENT BETWEEN ROOT
AND SOIL AT INCREASING DISTANCE FROM THE TREE BASE. IF THE CHANGE IN
ROOT LENGTH DENSITY IS SIMILAR OR SMALLER THAN THE CHANGE IN WATER-
POTENTIAL GRADIENT BETWEEN ROOT AND SOIL, THE DECREASE IN WATER-
POTENTIAL GRADIENT BETWEEN ROOT AND SOIL IS OF SIMILAR OR LARGER
IMPORTANCE FOR DETERMINING TREE-WATER EXTRACTION DISTRIBUTION
THROUGHOUT THE PROFILE THAN ROOT LENGTH DENSITY. THUS, MODELING OF
SPATIAL AGROFORESTRY SYSTEMS CANNOT ASSUME A DIRECT RELATION
BETWEEN TREE-WATER EXTRACTION AND ROOT LENGTH DENSITY, BUT NEEDS TO
INCLUDE DECREASING WATER-POTENTIAL GRADIENT BETWEEN ROOT AND SOIL
ALONG ROOTS WITH INCREASING DISTANCE TO THE STEM BASE, ESPECIALLY
OVER THE HORIZONTAL DIMENSION.
Importance of the Litter Layer
Increases soil biotic activity
Increases incorporation of organics
Slows down lateral movement of water
Impact of soil water availability on carbon sequestration in tree
biomass and soil in arid region of India.
Singh, G., Bilas Singh, Rathod, T. R.
Division of Forest Ecology and Desert Development, Arid Forest
Research Institute, Jodhpur (Rajasthan), India.
ARID REGIONS HAVE LOW CAPACITY TO SEQUESTER CARBON DUE
TO LOW SOIL WATER AVAILABILITY AND PLANT GROWTH. HOWEVER,
CONSIDERING THE LARGE EXTENT OF SUCH AREAS TOTAL CAPACITY
OF CARBON SEQUESTRATION MAY BE IMPORTANT.
ONE-YEAR-OLD PLANTED SEEDLINGS OF E. CAMALDULENSIS, A.
NILOTICA AND D. SISSOO WERE MAINTAINED AT DIFFERENT WATER
REGIMES BY RE-IRRIGATING THE SEEDLINGS AT 36.2 MM (T1), 26.5 MM
(T2), 20.2 MM (T3), 18.1 MM (T4) AND LIVE SAVING IRRIGATION (T5)
WHEN THE SOIL WATER CONTENT DECREASED TO 7.56, 5.79, 4.44,
3.23% AND DRYING OF LEAVES (T5) IN THE RESPECTIVE TREATMENTS
CONDUCTED AT THE EXPERIMENTAL FIELD OF ARID FOREST
RESEARCH INSTITUTE, JODHPUR, RAJASTHAN, INDIA.
CARBON CONTENT BOTH IN DRY BIOMASS AND SOIL INCREASED
WITH AGE OF THE SEEDLINGS, BUT IT DECREASED WITH
DECREASING IRRIGATION QUANTITY. A NEGATIVE CARBON BALANCE
WAS OBSERVED IN T5 AT 12 MONTHS AGE. AT THE AGE OF 48
MONTHS, CARBON CONTENT VARIED FROM 14.91 TO 0.72 KG
SEEDLING-1 IN E. CAMALDULENSIS, 8.67 TO 1.74 KG SEEDLING-1 IN A.
NILOTICA AND 12.42 TO 0.36 KG SEEDLING-1 IN D. SISSOO.
CARBON DENSITY WAS HIGH UNDER A. NILOTICA AND LOW UNDER E.
THE STUDY SUGGESTS THAT SEVERITY OF SOIL WATER STRESS
AFFECTED CARBON SEQUESTRATION, WHEREAS ENHANCED
AVAILABILITY OF SOIL WATER THROUGH IRRIGATION INCREASED
CARBON STORAGE IN BIOMASS AND SOIL.
THEREFORE, THERE IS SCOPE TO INCREASE CARBON
SEQUESTRATION IN DRY AREAS THROUGH RAINWATER
MANAGEMENT AND SUPPLYING ADDITIONAL IRRIGATION DURING
AVAILABILITY OF WATER. 36
Australian Journal of Botany
Impacts of tree plantations on groundwater in south-eastern Australia.
Benyon, R. G., Theiveyanathan, S., Doody, T. M.
Ensis, PO Box 946, Mount Gambier, SA 5290, Australia.
In some regions dependent on groundwater, such as the lower southeast
of South Australia in the Green Triangle, deep-rooted, woody vegetation
might have undesirable hydrological impacts by competing for finite,
good-quality groundwater resources.
In other regions, such as the Riverina in south-central New South Wales,
where rising water tables and associated salinization is threatening the
viability of agriculture, woody vegetation might have beneficial
hydrological impacts. In response to a growing need to better understand
the impacts of tree plantations on groundwater, annual evapotranspiration
and transpiration were measured at 21 plantation sites in the Green
Triangle and the Riverina. Sources of tree water uptake from rainfall and
groundwater were determined by measurements of evapotranspiration
and soil water over periods of 2-5 years.
In the Green Triangle, under a combination of permeable soil over
groundwater of low salinity (<2000 mg L-1) at 6-m depth or less, in a highly
transmissive aquifer, annual evapotranspiration at eight research sites in
Pinus radiata and Eucalyptus globulus plantations averaged 1090 mm
year-1 (range 847-1343 mm year-1), compared with mean annual
precipitation of 630 mm year-1. These plantation sites used groundwater
at a mean annual rate of 435 mm year-1 (range 108-670 mm year-1).
At eight other plantation sites that had greater depth to the water table or a
root-impeding layer, annual evapotranspiration was equal to, or slightly
less than, annual rainfall (mean 623 mm year-1, range 540-795 mm year-1).
In the Riverina, where groundwater was always present within 3 m of the
surface, Eucalyptus grandis trees at three sites with medium or heavy
clay, alkaline, sodic, saline subsoils used little or no groundwater,
whereas E. grandis and Corymbia maculata trees at a site with a neutral
sandy soil and groundwater of low salinity used 380 and 730 mm year-1 of
groundwater (respectively 41 and 53% of total annual evapotranspiration).
We conclude that commonly grown Eucalyptus species and P. radiata are
able to use groundwater under a combination of light- or medium-textured
soil and shallow depth to a low-salinity water table 37
Affect of Micropores in the Soil
• Lead to better soil structure
• Increases organic matter incorporation
• Increases percolation rates and root penetration
Water Resources Research
Ecohydrological controls on soil moisture and hydraulic
conductivity within a pinyon-juniper woodland.
Lebron, I., Madsen, M. D., Chandler, D. G., Robinson, D. A., Wendroth, O., Belnap, J.
Department of Soils and Biometeorology, Utah State University, Logan, Utah, USA.
THE IMPACT OF PINYON-JUNIPER WOODLAND ENCROACHMENT ON
RANGELAND ECOSYSTEMS IS OFTEN ASSOCIATED WITH A REDUCTION OF
STREAMFLOW AND RECHARGE AND AN INCREASE IN SOIL EROSION. THE
OBJECTIVE OF THIS STUDY IS TO INVESTIGATE VEGETATIONAL CONTROL ON
SEASONAL SOIL HYDROLOGIC PROPERTIES ALONG A 15-M TRANSECT IN
PINYON-JUNIPER WOODLAND WITH BIOCRUST.
WE DEMONSTRATE THAT THE JUNIPER TREE CONTROLS SOIL WATER CONTENT
(SWC) PATTERNS DIRECTLY UNDER THE CANOPY VIA INTERCEPTION, AND
BEYOND THE CANOPY VIA SHADING IN A PREFERRED ORIENTATION, OPPOSITE
TO THE PREVAILING WIND DIRECTION. THE JUNIPER ALSO CONTROLS THE SWC
AND UNSATURATED HYDRAULIC CONDUCTIVITY MEASURED CLOSE TO WATER
SATURATION (K(H)) UNDER THE CANOPY BY THE CREATION OF SOIL WATER
REPELLENCY DUE TO NEEDLE DROP.
WE USE THIS INFORMATION TO REFINE THE HYDROLOGIC FUNCTIONAL UNIT
(HFU) CONCEPT INTO THREE INTERACTING HYDROLOGIC UNITS:
CANOPY PATCHES, INTERCANOPY PATCHES, AND A TRANSITIONAL UNIT
FORMED BY INTERCANOPY PATCHES IN THE RAIN SHADOW OF THE JUNIPER
SPATIAL AUTOREGRESSIVE STATE-SPACE MODELS SHOW THE CLOSE
RELATIONSHIP BETWEEN K(H) CLOSE TO SOIL WATER SATURATION AND SWC
AT MEDIUM AND LOW LEVELS, INTEGRATING A NUMBER OF INFLUENCES ON
Soil Frost Types
– Small frost crystals intermingled with soil particles
– Found in woodland soils with litter
– May be more permeable than unfrozen soil
– Has loose porous structure
– Found in highly aggregated soils and also formed in
organic layers and litter layers
Effects Of Trees On Soils
The capacity of trees to maintain or improve soils is shown by the high
fertility status and closed nutrient cycling under natural forest, the
restoration of fertility under forest fallow in shifting cultivation, and the
experience of reclamation forestry and agroforestry.
Soil transects frequently show higher organic matter and better soil
physical properties under trees. Some species, most notably Faidherbia
albida, regularly give higher crop yields beneath the tree canopy. Trees
improve soil fertility by processes which:
* increase additions to the soil;
* reduce losses from the soil;
* improve soil physical, chemical and biological conditions.
The most important sets of processes are those by which trees:
* check runoff and soil erosion;
* maintain soil organic matter and physical properties;
* increase nutrient inputs, through nitrogen fixation and uptake from deep
* promote more closed nutrient cycling.
American Society of Agricultural Engineers
Vol. 34(1): January-February 1991
Citrus Tree Spacing Effects on Soil Water
Use, Root Density, and Fruit Yield
J. D. Whitney, A. Elezaby, W. S. Castle, T. A. Wheaton, R. C. Littell
Soil water content, root density, and fruit yield measurements were
made on 'Hamlin' orange trees on Milam rootstock at two tree
spacings-6 x 4.5 m (370 trees/ ha) and 4.5 x 2.5 m (889 trees/ ha).
Soil water use per unit land area for the seven- and eight-year-old
trees was not significantly affected by tree spacing.
Water use was greatest underneath the canopy dripline and generally
decreased with increasing soil depth to 1.65 m.
Root densities of the seven-year-old trees were greater at the 4.5 X
2.5 m spacing and generally decreased with depth.
Fruit yields per ha were greater for the 4.5 x 2.5 m spacing in the
early years, were comparable for both spacings during the seventh
and eighth years, and favored the 6 x 4.5 spacing in the 9th year.
Soil Frost Types
– Forms partially fused, columnar ice crystals
– Connects a heaved soil surface to the soil below
– Forms intricate multiple thin ice lenses
– Common in soils going through freeze-thaw sequences
– Common in exposed soil areas (agriculture)
– Much less permeable that other frost types
Tree effects on soil
Trees may also adversely affect associated crops. The effects of
allelopathy (inhibition effects) have probably been exaggerated by
mistaking them for, or confounding them with, other processes.
Competition for water is a serious but not insuperable problem in all dry
environments, whereas competition for nutrients has rarely been
Where the net effect of tree—crop interactions is positive, the length of
the tree—crop interface, or extent of the ecological fields, should be
maximized. If the net effect is negative, the aim of agroforestry system
design should be to reduce the length of the interface.
A range of properties have been identified which make tree species
suited to soil improvement. For many purposes, high biomass
production, nitrogen fixation, a combination of fine feeder roots with tap
roots and litter with high nutrient content are suitable. Tolerance to
initially poor soil conditions is clearly needed for reclamation. About 100
species have been identified which are known to fulfil soil-improving
functions, but there is much scope to increase this range.
Implications of Frost Types
• Forests and prairies rarely yield runoff regardless of
steepness, even when frozen
• Forested areas provide storm water protection and protect
the quantity and quality of groundwater
Rainfall interception by an isolated evergreen oak tree in a Mediterranean
David, T. S., Gash, J. H. C., Valente, F., Pereira, J. S., Ferreira, M. I., David, J. S.
Estação Florestal Nacional, INIAP, Av. da República, Quinta do Marquês, 2780-159
Redistribution of ground-level rainfall and interception loss by an isolated
Quercus ilex tree were measured over 2 years in a Mediterranean oak
savannah. Stemflow, meteorological variables and sap flow were also
Rainfall at ground level was measured by a set of rain-gauges located in a
radial layout centred on the tree trunk and extending beyond the crown
Interception loss was computed as the difference between the volume of
rainwater that would reach the ground in the absence of the tree and the
volume of water that actually fell on the ground sampling area (stemflow
included). This procedure provided correct interception loss estimates,
irrespective of rainfall inclination.
Results have shown a clear non-random spatial distribution of ground-level
rainfall, with rainwater concentrations upwind beneath the crown and rain-
Interception loss amounted to 22% of gross rainfall, per unit of crown-
projected area. Stand interception loss, per unit of ground area, was only
8% of gross rainfall and 28% of tree evapotranspiration. These values reflect
the low crown cover fraction of the stand (0.39) and the specific features of
the Mediterranean rainfall regime (predominantly with few large storms).
Nevertheless, it still is an important component of the water balance 43
these Mediterranean ecosystems .
Groundwater –Surface Water Flows
Tree root damage to buildings. Volume 1: causes, diagnosis and remedy. Volume 2:
patterns of soil drying in proximity to trees on clay soils.
Tree root damage to buildings. Volume 1: causes, diagnosis and remedy.
Volume 2: patterns of soil drying in proximity to trees on clay soils.
Biddle, P. G.
Willowmead, Ickleton Road, Wantage, Oxon. OX12 9JA, UK.
This 2-volume set of books provides a comprehensive analysis of, and practical
guide to, how the interaction of trees, soils and water can cause foundation
movement and damage to buildings. The problems addressed are multidisciplinary,
involving structural engineers, engineers, arboriculturalists, soil scientists, insurers
and their loss adjusters, architects, and builders and planners, as well as providing
work to the legal profession. All aspects of the problems involved are addressed.
Volume 1 has 20 chapters, each with a brief summary and a case study at the end;
essential points are highlighted.
The first 10 chapters describe the interactions of trees, soils, water and buildings: (1)
Introduction; (2) The tree - an account of tree physiology and growth; (3) The root
system; (4) The soil - types and behaviour in relation to water content; (5) Seasonal
changes in soil moisture content; (6) Persistent moisture deficits - when the winter
process of rewetting of the soil after summer drying is not complete; (7) Interaction
between trees and buildings - soil and foundation movements, buildings and
persistent water deficit, and the influences of buildings on the soil and tree roots; (8)
Influence of the weather; (9) Comparative effects of different species, and of
individual trees and groups; and (10) Other forms of damage by tree roots - direct
physical damage and damage to drains and underground services. Chapters 11-16
describe the investigation of damage: (11) Strategy for investigating damage; (12-14)
Site investigations: I. The building; II, The soil; and III. The tree; (15) Monitoring
building movement; and (16) Heave and recovery: diagnosis and prediction. Chapters
17-20 address remedy and prevention: (17) Remedial action after damage; (18)
Prediction and prevention of damage; (19) The legal framework; and (20) A revised
role for the professions. Volume 1 ends with a list of references, cross references
between botanical and common names, and a subject index.
Volume 2 presents the accumulated results from 3 research projects which started in
1978 (with the Milton Keynes (UK) Development Corporation), and were extended in
1981 (under instruction from the UK National House-Building Council) and 1983
(under instruction from the UK Department of the Environment). These investigated
the pattern of soil drying, both spatially and with time, that occurs in the proximity of
trees on clay soils. A total of 60 trees on open-field sites were studied.
These included a range of tree species and clay soil types. The relevance and
application of these results to urban situations are addressed in Volume 1. The
methods used in the research are described in the introduction to Volume 2 - they
involved the use of 5 neutron probe access tubes per tree, by means of which the soil
water profiles of each were monitored over long periods. The rest of the volume
presents detailed research data for each tree, including photographs and coloured45
diagrams. These cover the overall time period 1978-94, although different periods
apply to different trees.
Black Earth Creek Study
• Black Earth Creek receives 80% of its water from groundwater
• Main recharge occurs in spring and fall
• Recharge from the agricultural uplands is highly variable
• Wooded hill slopes generate no significant runoff
• Forested slopes are significant recharge areas
Effect of soil density on the growth of the root systems of
Korotaev, A. A.
Lesotekhnicheskaya Akademiya, Sankt-Peterburg, Russia.
Seedlings of Picea abies, Larix sibirica, Pinus sylvestris, Betula
pendula, Quercus robur and Tilia cordata were grown in soils of
density 1.2, 1.3...1.9 g/cm³.
Data are presented on depth of root penetration and total root
biomass. In terms of root growth rate and the ability to penetrate
dense soil layers, oak and larch were the best and spruce and lime
were the poorest species.
The critical density of clay loam illuvial soil is 1.89 g/m³ for oak,
1.84 for birch, 1.80 for birch, 1.72 for pine, 1.61 for spruce, and 1.55
g/cm³ for lime. In experiments where the soil density in the lower
horizon was greater, the total root biomass produced was virtually
the same, as reduced root growth in the dense soil was
compensated by more active root growth in the topsoil .
Urban trees enhance water infiltration
Traditional stormwater management focuses on regulating the flow of
runoff to waterways, but generally does little to restore the hydrologic cycle
disrupted by extensive pavement and compacted urban soils with low
The lack of infiltration opportunities affects groundwater recharge and has
negative repercussions on water quality downstream.
Researchers know that urban forests, like rural forest land, can play a
pivotal role in stormwater mitigation, but developing approaches that
exploit the ability of trees to handle stormwater is difficult in highly built city
cores or in urban sprawl where asphalt can be the dominant cover feature.
Volume 44, Number 4 / October, 2009
Transpiration and Root Development of Urban Trees in Structural Soil
Julia Bartens , Susan D. Day , J. Roger Harris, Theresa M. Wynn and Joseph E. Dove
Stormwater management that relies on ecosystem processes, such as tree
canopy interception and rhizosphere biology, can be difficult to achieve in
built environments because urban land is costly and urban soil
inhospitable to vegetation. Yet such systems offer a potentially valuable
tool for achieving both sustainable urban forests and stormwater
management. We evaluated tree water uptake and root distribution in a
novel stormwater mitigation facility that integrates trees directly into
detention reservoirs under pavement.
The system relies on structural soils: highly porous engineered mixes
designed to support tree root growth and pavement.
To evaluate tree performance under the peculiar conditions of such a
stormwater detention reservoir (i.e., periodically inundated), we grew
green ash (Fraxinus pennsylvanica Marsh.) and swamp white oak
(Quercus bicolor Willd.) in either CUSoil or a Carolina Stalite-based mix
subjected to three simulated below-system infiltration rates for two
Infiltration rate affected both transpiration and rooting depth. In a factorial
experiment with ash, rooting depth always increased with infiltration rate
for Stalite, but this relation was less consistent for CUSoil. Slow-drainage
rates reduced transpiration and restricted rooting depth for both species
and soils, and trunk growth was restricted for oak, which grew the most in
Transpiration rates under slow infiltration were 55% (oak) and 70% (ash) of
the most rapidly transpiring treatment (moderate for oak and rapid for
ash). We conclude this system is feasible and provides another tool to
address runoff that integrates the function of urban green spaces with
other urban needs.
Trees enhance water infiltration
Virginia Tech scientists used two container experiments to
establish that urban tree roots have the potential to penetrate
compacted subsoils and increase infiltration rates in
reservoirs being used to store stormwater. In one study, roots
of both black oak and red maple trees penetrated clay loam
soil compacted to 1.6 g cm-3, increasing infiltration rates by
an average of 153%.
In another experiment, researchers created a small-scale
version of the stormwater best management practice (BMP)
under study by the three universities. This BMP includes a
below-pavement stormwater detention reservoir constructed
of structural soil. Structural soils are engineered mixes
designed to both support pavement loads and simultaneously
provide rooting space for trees. In this study, green ash trees
increased the average infiltration rate by 27 fold compared
with unplanted controls.
In the experiment, a structural soil reservoir (CUSoil, Amereq
Corp., New York) was separated from compacted clay loam
subsoil (1.6 g cm-3) by a woven geotextile in 102-liter
containers. The roots of ash trees planted in the structural soil
penetrated both the geotextile and the subsoil within two
Trees and Storm Water:
• The impact of urban trees on hydrology is
extremely variable and complex, in general
increases in tree cover and tree size over a site will
result in reduced total runoff amounts and peak
• Effects are greatest during the growing season
• Effects are greatest on sites whose soils are
Help Cities Meet Clean Water Regulations
Tree cover in urban areas can provide cities with reduced costs for
stormwater management and improvement in water quality.
Forests has developed a computer software package to measure the
effects of urban tree cover and impervious surfaces on stormwater
that will help city managers meet ever tightening water quality regula-
tions. Scientific research and time-tested engineering practices pro-
vide the basis for the software calculations.
Trees and Storm Water:
• Trees have a relatively greater effect on smaller storm runoff
amounts than on large storm events
• Surface and below-ground effects on runoff are much more
significant than the above-ground effects
All of the effects on runoff are greatest when urban trees are
large and well-established on undisturbed sites
Vegetasi pohon sangat berpengaruh positif terhadap lingkungan
termalnya dalam hal laju penurunan temperatur udara dan temperatur
Dengan demikian maka mekanisme pohon dalam pengendalian
lingkungan termal dapat diintepretasikan sebagai berikut :
- Pohon berpengaruh positif terhadap temperatur udara berdasarkan
mekanisme pembayangan (canopy effect), di mana pohon memayungi
daerah di bawahnya dari sinar matahari langsung sehingga tidak menjadi
panas dan berpengaruh pada udara.
- Pohon berpengaruh positif terhadap proses pendinginan (penurunan
temperatur udara sore hari) berdasarkan mekanisme evapotranspiration,
di mana pelepasan air dari permukaan daun pada sore hari mendinginkan
permukaan daun dan mempengaruhi temperatur udara di sekitarnya.
-Pohon berpengaruh negatif terhadap proses pemanasan (naiknya
temperatur udara pagi hari) berdasarkan mekanisme ‗selimut‘ di mana
canopy menghalangi pertukaran panas dengan daerah sekitarnya
sehingga lingkungan di bawahnya cepat menjadi panas. Efek dari laju naik
temperatur udara tidak terlalu berpengaruh pada temperatur udara rata-
Can urban tree roots improve infiltration through
compacted subsoils for stormwater management?
Global land use patterns and increasing pressures on water
resources demand creative urban stormwater management.
Strategies encouraging infiltration can enhance groundwater
recharge and water quality. We examined whether tree roots can
penetrate compacted subsoils and increase infiltration rates in
the context of a novel infiltration BMP (I-BMP).
Urban subsoils are often relatively impermeable, and the
construction of many stormwater detention best management
practices (D-BMPs) exacerbates this condition. Root paths can
act as conduits for water, but this function has not been
demonstrated for stormwater BMPs where standing water and
dense subsoils create a unique environment. We examined
whether tree roots can penetrate compacted subsoils and
increase infiltration rates in the context of a novel infiltration
BMP (I-BMP). Black oak (Quercus velutina Lam.) and red maple
(Acer rubrum L.) trees, and an unplanted control, were installed
in cylindrical planting sleeves surrounded by clay loam soil at
two compaction levels (bulk density = 1.3 or 1.6 g cm−3) in
irrigated containers. Roots of both species penetrated the more
compacted soil, increasing infiltration rates by an average of
Similarly, green ash (Fraxinus pennsylvanica Marsh.) trees were
grown in CUSoil (Amereq Corp., New York) separated from
compacted clay loam subsoil (1.6 g cm−3) by a geotextile. A
drain hole at mid depth in the CUSoil layer mimicked the
overflow drain in a stormwater I-BMP thus allowing water to pool
above the subsoil.
Roots penetrated the geotextile and subsoil and increased
average infiltration rate 27-fold compared to unplanted
controls. Although high water tables may limit tree rooting
depth, some species may be effective tools for increasing water
infiltration and enhancing groundwater recharge in this and
other I-BMPs (e.g., raingardens and bioswales). 53
Urban tree roots have the potential to penetrate compacted subsoils
and increase infiltration rates in reservoirs being used to store
Bartens et al. Can Urban Tree Roots Improve Infiltration through
Compacted Subsoils for
Stormwater Management? Journal of Environmental Quality, 2008; 37
(6): 2048 55
Landscape ecology of trees and forests. Proceedings of the twelfth
annual IALE (UK) conference, Cirencester, UK, 21-24 June 2004
Investigating the impact of tree shelter belts on
Carroll, Z. L., Bird, S. B., Emmett, B. A., Reynolds, B., Sinclair, F. L.
Centre for Ecology and Hydrology, Orton Building, Deiniol Road, Bangor,
Gwynedd, Wales, LL57 2UP, UK.
There is growing concern that modern agricultural practices have
reduced the infiltration capacity of the soil, thereby reducing the
soil's ability to absorb rainwater. There are few quantitative data
available, however, on the impact of land use on runoff and flood
A preliminary study was undertaken in the Nant Pontbren
catchment, mid-Wales, UK. This land is used extensively for
grazing and experimental tree shelterbelts were established in
selected pastures. Infiltration rates were up to 60 times higher in
areas planted with trees than in adjacent grazed pastures and
significant differences were also observed for soil moisture and pH.
Surprisingly, soil bulk density varied little between the two areas.
The results indicate that more research is needed to gain a better
understanding of the processes in operation. This study
demonstrates that farm trees could represent a key landscape
feature, reducing runoff even when only a small proportion of the
ISHS Acta Horticulturae 620: XXVI International Horticultural Congress:
Asian Plants with Unique Horticultural Potential: Genetic Resources,
Cultural Practices, and Utilization
EFFECT OF RAINFALL INTERCEPTION ON SOIL MOISTURE, TREE SAP
FLOW, AND FRUIT QUALITY IN PEACH (PRUNUS PERSICA)
D.G. Choi, D.C. Choi, D.H. You, H.G. Kim, J. Ryu, S.D.
Effect of soil covering with black polyethylene film for rainfall interception
(RI) on soil moisture, tree sap flow, and fruit quality in ‗Okubo‘ peach were
investigated to find out the factor decreasing fruit quality, when it rained at
fruit mature season.
Cell size of fruit was rapidly increased until the late of May, nearly stopped
at the early of June, and regrew from the late of June in the natural
condition. Change of soil water was less and slower in the treatment of RI
than that in the control.
The RI retarded the soil water increasing, whereas soil water in the control
plot fluctuated with rainfall amount change.
Soil water content in RI plot showed 80% lower at small raining and 40%
lower at heavy raining than that in the control plot. Amount of tree sap flow
during raining was high in all treatments.
Tree sap flow kept high during the stable soil water period without rain,
whereas it did lower during the unstable soil water period after rain.
Pit splitting rate was 20% in control tree and 10% in the RI.
Fruit hardness and sugar content were higher in RI treatment than that in
the control. Therefore, taste of fruits in the RI treatment was better than that
of the control.
Agroforestry Systems (Netherlands)
Effects of mulching with multipurpose-tree prunings on soil and water
run-off under semi-arid conditions in Kenya.
Omoro, L. M. A., Nair, P. K. R.
Agroforestry Program, University of Florida, Gainesville, Florida, USA.
The effect of adding leaf mulches of Grevillea robusta, Cassia siamea and
Gliricidia sepium on the rate of soil and water runoff from a crop field
were studied during 2 cropping seasons in an Alfisol under semi-arid
conditions in Kenya.
Two rates of mulch of each species (2.24 t and 4.48 t, on dry matter basis,
per ha) and a no-mulch control constituted the 7 treatments. Soil and
water runoff losses after each major rainfall event and the changes in
ground and crop cover were measured.
Rainfall erosivity and changes in soil bulk density and infiltration rate
were also determined. Soil losses from the plots with mulches of C.
siamea, G. sepium and G. robusta were lower than those from the control.
Over the 2 seasons, the cumulative soil losses from plots mulched with
cassia, gliricidia and grevillea were 11%, 57% and 81% of that of the
control plot. Similarly, water runoff losses from cassia, gliricidia and
grevillea mulch plots were 28%, 48% and 58% of that of the control plot,
Thus, cassia was found to be better than gliricidia and grevillea in
reducing both soil and water runoff losses. Soil bulk density did not
change while the infiltration rate at the end of the experiment was higher
than in the beginning. However, there were no significant differences in
these soil physical properties among the treatments
So How Do We Protect Water Quality and Our Streams as Watersheds
Trees and forests play an incredible role in reducing stormwater in several ways
and removing or filtering pollutanting that would otherwise wind up in our
Tree canopies intercept and capture rainfall, reducing the amount that reaches the
ground. In urban and suburban settings, a single deciduous tree can intercept
between 500 and 760 gallons per year, while a mature evergreen can intercept over
4,000 per year.
Tree roots and forest soils allow for better infiltration of rainfall with
rates of up to 15 inches per hour. The leaf littered forest floor acts like
a gaint sponge, allowing for slow infiltration into soils befre releasing it
to natural channels and recharging ground water.
Tree consumer stormwater through a process called evapotranspiration. Water is
taken up by roots and move up through the tree until it is transpired back into the
atmosphere as water vapor. A single mature oak tree can consume (transpire) over
40,000 gallons of water each year.
Trees are very good at removing pollutants such as nitrates & phosphates; and
other contaminates such as heavy metals, pesticides, solvents, oils, and
hydrocarbons that are found in stormwater.
Trees and Riparian Forests protect and buffer streams and are critical to
maintaining healthy, clean streams. Tree roots provide streambank stability,
reducing erosion, filter out sediments, remove nutrients, shade and cool the water,
provide habitat for many different species, and provide the primary food source
for aquatic insects that are a critical part of the aquatic food chain.
Until recently, stormwater management strategies focused on detaining large
volumes of water in basins that had little to no effect on removing the pollutants in
the stormwater. In December 2006, PA DEP unveiled new stormwater best
management practices (BMPs) that work to protect water quality and put
stormwater back into the ground where it fell. One of the 10 principles in the BMP
manual is to preserve and utilize natural systems such as forests, trees, and native
Trees and Forests Reduce the Impacts of Stormwater
As we begin to remove forest canopy and replace it with roads, parking
lots, driveways, homes, patios, pools (impervious surfaces) and even
grass, we immediately have impact on watersheds and receiving
streams (or lakes).
With the increased amount of impervious surfaces, water runs off the
land, traveling on the surface towards the streams. As this ‗storm water
runoff‘ travels to the streams it collects pollutants and increases speed.
The changes to the landscape, not only increase the volume of water
that goes to the stream, it also shortens the amount of time it takes the
water to get to the stream.
These increased or peak flows cause water to move quickly to the
streams. This leads to flooding, streambank erosion, widening of
streams, sediment deposited in streams, a loss of fish habitat, and
decline in water quality. In Pennsylvania there are over 12,200 miles of
polluted streams and over 3,000 miles of streams that are impaired by 60
storm water runoff.
Analysing the space-time distribution of soil water storage of a forest
ecosystem using spatio-temporal kriging.
Jost, G., Heuvelink, G. B. M., Papritz, A.
Institute of Forest Ecology, BOKU-University of Natural Resources and Applied
Life Sciences, Vienna, Peter Jordan Str. 82, A-1190 Vienna, Austria.
Editors: Oliver, M. A., Lark, R. M.
In forest the soil water balance is strongly influenced by tree species composition.
For example, differences in transpiration rate lead to differences in soil water
storage (SWS) and differences in canopy interception cause differences in
To analyse the influence of tree species composition on SWS at the scale of a
forest stand, we compare spatio-temporal patterns in vegetation and SWS.
Geostatistical space-time models provide a probabilistic framework for mapping
SWS from point observations.
The accuracy of these models may be improved by incorporating knowledge about
the process of evapotranspiration. In this paper we combine a physical-
deterministic evapotranspiration model with space-time geostatistical
interpolation to predict soil water storage in the upper 30 cm of soil (SWS30) for a
0.5 ha plot in a mixed stand of Norway spruce (Picea abies (L.) Karst.) and
European beech (Fagus sylvatica L.) in Kreisbach, Lower Austria.
Soil water storage was measured at 198 locations by permanently installed wave
guides. This was repeated 28 times, about every two weeks during the growing
seasons of 2000 and 2001. Incorporation of a process-based model in space-time
prediction of SWS30 reduced the effect of precipitation on SWS30 predictions
prior to precipitation.
Spatial patterns of SWS30 between the permanent wilting point and field capacity
depend on the precipitation and drying history, which is affected by vegetation.
Early in the growing season spruce starts to transpire markedly, which is common
for coniferous trees. During dry periods, spruce reduces transpiration earlier than
beech. Overall beech transpires more than spruce during the growing season.
The greater transpiration rates of beech are compensated for by greater soil water
recharge after precipitation because less rainfall is intercepted.
At low water contents near the permanent wilting point SWS30 was spatially quite
uniform. This was also the case at water contents nearfield capacity, probably
because the soil physical parameters varied little. Space-time interpolation of
SWS30 and the prediction of soil water discharge and soil water recharge during
periods of drying and rewetting demonstrate the important role of vegetation on
the spatial patterns of SWS30.
Benefits of Trees
Most trees and shrubs in cities or communities are planted to
provide beauty or shade. These are two excellent reasons for
Woody plants also serve many other purposes, and it often is
helpful to consider these other functions when selecting a tree
or shrub for the landscape. The benefits of trees can be
grouped into social, communal, environmental, and economic
Variability of surface runoff generation and infiltration rate
under a tree canopy: indoor rainfall experiment using Japanese
cypress (Chamaecyparis obtusa)
Kazuki Nanko , Yuichi Onda , Akane Ito , Shun Ito , Shigeru Mizugaki ,
Hydrological Processes. Volume 24 Issue 5, 2010 Pages 567 - 575
To estimate the variability of surface runoff generation and the
infiltration rate on a bare surface in a forested area, indoor
experiments were conducted using 13 runoff boxes and a single
transplanted Japanese cypress tree (9·8 m in height) in a large-
scale rainfall simulator with spray nozzles (at a height of 16 m).
The surface runoff was measured for applied rainfall and for 12
kinds of throughfall with different intensities and kinetic energy
(KE) (found among measuring points and canopy structures).
While no surface runoff was observed for the applied rainfall,
surface runoff was observed for throughfall in each runoff box.
Compared with the applied rainfall, the throughfall had larger
drops due to canopy drip generation and thus had higher
kinetic energy, which decreased the infiltration capacity.
The maximum stable infiltration rate (IRMAX) was lowest for
throughfall (44·2 mm h-1). Surface runoff generation and
infiltration rates varied greatly under the canopy, even though
the rainfall applications were identical and the runoff boxes had
identical initial soil properties. The variability of IRMAX, ranging
from 44·2 to 120·2 mm h-1, was caused by the variability of the
throughfall intensity and kinetic energy. The index showing the
best correlation to IRMAX was the effective unit kinetic energy
(KE0 mm: J m-2 mm-1). The prediction of surface runoff
generation in a forested area requires estimations of the spatial
variations of the amount and kinetic energy of throughfall.
Copyright © 2010 John Wiley & Sons, Ltd. 63
Logging effects on soil moisture losses
Ziemer, Robert R.
Ph.D. dissertation, Colorado State University, Ft. Collins, Colorado. 132 p.
The depletion of soil moisture within the surface 15 feet by an isolated
mature sugar pine and an adjacent uncut forest in the California Sierra
Nevada was measured by the neutron method every 2 weeks for 5
Soil moisture recharge was measured periodically during the intervening
winters. Groundwater fluctuations within the surface 50 feet were
continuously recorded during the same period. Each fall, a wetting front
progressed from the soil surface, eventually recharging the entire soil
profile to ""field capacity"".
During the recharge period, although the top portion of the soil was at
""field capacity"", the trees continued to deplete moisture from the drier
soil below the wetting front into early winter. Groundwater levels began to
rise within days after rainfall, whereas weeks or months were required for
the wetting front to progress through the unsaturated zone above the
Soil moisture depletion by the isolated tree was maximum at a depth of 8
to 13 feet and extended about 15 feet away from the tree. The influence of
the tree on soil moisture depletion extended to a depth of about 18 feet
and to a distance of about 40 feet. An excellent linear relationship was
found between the quantity of soil moisture depleted by the tree at the
end of the summer and distance from the tree.
The isolated tree used between 2200 and 2600 cubic feet more soil
moisture than a bare portion of the plot outside of the influence of the
Peranan vegetasi pohon
Burgess, S. and 5 others. 1998. Trees as water pumps: restoring water balances in
Australian and Kenyan soils. Agroforestry Today 10(3): 18-20).
MacDicken, K.G. 1991. Selection and Management of Nitrogen Fixing Trees. Winrock
International, Morriltion, Arkansas, USA.
Nair, P.K.R., and Latt, C.R. (eds.) 1997. Directions in tropical agroforestry research.
Agroforestry Systems, Special Issue, 38: 1-249.
Niang, A. and 5 others. 1999. Soil fertility replenishment in western Kenya.
Agroforestry Today 11(1-2): 19-21.
von Carlowitz, P.G. 1986. Multipurpose Tree and Shrub Seed Directory. ICRAF,
von Carlowitz, P.G., Wolf, G.V., and Kemperman, R.E.M. 1991. Multipurpose Tree and
Shrub Database. An Information and Decision-support System. GTZ, Eschborn,
Webb, D.B., Wood, P. J., Smith, J.P., and Henman, G.S. 1984. A Guide to Species
Selection in Tropical and Sub-tropical Plantations. Commonwealth Forestry
Institute, Oxford, UK.
Young, A. 1989. Agroforestry for Soil Conservation. CAB International, Wallingford,
Hydrol. Earth Syst. Sci., 13, 1809-1821, 2009
© Author(s) 2009. This work is distributed
under the Creative Commons Attribution 3.0 License.
Significance of tree roots for preferential infiltration in
B. Lange, P. Lüescher, and P. F. Germann
It is generally recognized that roots have an effect on
infiltration. In this study we analysed the relation between root
length distributions from Norway spruce (Picea abies (L.)
Karst), silver fir (Abies alba Miller), European beech (Fagus
sylvatica L.) and preferential infiltration in stagnic soils in the
northern Pre-Alps in Switzerland. We conducted irrigation
experiments (1 m2) and recorded water content variations with
time domain reflectometry (TDR). A rivulet approach was
applied to characterise preferential infiltration. Roots were
sampled down to a depth of 0.5 to 1 m at the same position
where the TDR-probes had been inserted and digitally
The basic properties of preferential infiltration, film thickness of
mobile water and the contact length between soil and mobile
water in the horizontal plane are closely related to root
An increase in root density resulted in an increase in contact
length, but a decrease in film thickness. We modelled water
content waves based on root densities and identified a range of
root densities that lead to a maximum volume flux density and
These findings provide convincing evidence that tree roots in
stagnic soils represent the pore system that carries preferential
infiltration. Thus, the presence of roots should improve
Peranan bentang lahan
Social Benefits OF TREE
We like trees around us because they make life more pleasant. Most of
us respond to the presence of trees beyond simply observing their
beauty. We feel serene, peaceful, restful, and tranquil in a grove of trees.
We are at home there. Hospital patients have been shown to recover
from surgery more quickly when their hospital room offered a view of
The strong ties between people and trees are most evident in the
resistance of community residents to removing trees to widen streets.
Or we note the heroic efforts of individuals and organizations to save
particularly large or historic trees in a community.
The stature, strength, and endurance of trees give them a cathedral-like
quality. Because of their potential for long life, trees frequently are 67
planted as living memorials. We often become personally attached to
trees that we or those we love have planted.
Austral ecology ISSN 1442-9985
2005, vol. 30, no3, pp. 336-347
Woodland trees enhance water infiltration in a fragmented
agricultural landscape in eastern Australia
ELDRIDGE David J. ; FREUDENBERGER David
Since European settlement, Eucalyptus box woodlands have been
substantially modified by agricultural practices, and in many areas in
southern Australia are now restricted to scattered or clumped trees.
We report here on a study to examine the impact of trees on water flow
(infiltration) in an agricultural landscape with substantial areas of extant
native vegetation. We examined infiltration through coarse- and fine-
textured soils within four landscape strata, the zones below Eucalyptus
melliodora and Callitris glaucophylla canopies, the intertree zone
dominated by perennial grasses and a landscape homogenized by
cultivation and dominated by annual crops.
We measured sorptivity, the early phase of water flow, and steady-state
infiltration with disc permeameters at two supply potentials. These
different potentials enabled us to separate infiltration into (i) flow
through large (biopores) and small pores and (ii) flow through small
pores only where biopores are prevented from conducting water. On the
fine-textured soils, both sorptivity and steady-state infiltration were
significantly greater (approximately fivefold) under the timbered strata
compared with the grassy slopes or cultivation. Differences were
attributable to the greater proportion of macropores below the tree
canopies compared with the nontimbered strata. The lack of a significant
difference on the coarse-textured soils, despite their macropore status,
was attributed to differences in surface litter and plant cover, which
would maintain continuous macropores at the surface and thus conduct
large amounts of water.
The tendency of slopes covered by cryptogamic crusts and grasses to
shed run-off and for the trees to absorb substantial quantities of water
reinforced the important ecological service provided by trees, which
moderates large run-off events and captures small amounts of water
leaking from the grassy patches. In the absence of these 'ecosystem
wicks', run-off would find its way into regional groundwater and
contribute to rising salinity.
NERACA AIR DI ALAM
Journal of Hydrology (Amsterdam)
Soil water depletion and recharge patterns in mixed and pure forest
stands of European beech and Norway spruce.
Schume, H., GeorgJost, Hager, H.
Institute of Forest Ecology, BOKU, University of Natural Resources and
Applied Life Sciences, Peter Jordan Strasse 82, Vienna A-1190, Austria.
Automated time domain reflectometry (TDR) measurements in high
resolution over soil depth and over time were performed in a mixed
beech-spruce and a spruce stand during two hydrologically contrasting
Soil drying was more intensive and reached deeper soil layers in the
mixed stand, which on the other hand allowed more stand precipitation,
compensating for the higher evapotranspiration rates. These results were
confirmed by a large number of spatially distributed TDR measurements
along grids of different spacing, which additionally covered a beech
stand. Spatial water depletion patterns of the topsoil in spring appeared
to be largely congruent with tree species distribution and reflected the
higher water consumption of fully foliated beech. Variability was highest
in the mixed stand, where a spatial correlation within a range of about 7
m was observed.
The pure stands lacked spatial correlation. The effect of the mixed stand
on soil water depletion and recharge turned out to be non-additive as
compared to the pure stands of beech and spruce: changes of soil water
storage under the mixed stand almost equalled the values measured in
the beech stand. During selected drying periods in 2000 average daily
water extraction rates from the uppermost 60 cm of soil amounted to 1.65
mm in the beech as well as in the mixed stand, which is about 45% more
than under pure spruce.
Maximum differences of up to 84% occurred in periods with high
evaporative demand. The over-proportionate evapotranspiration of the
mixed stand was exclusively attributable to beech, which deepened and
intensified its fine-root system in mixture, while spruce rooted more
shallowly. The mixed stand extracted a higher percentage of water from
deeper soil layers than the pure stands.
Salah satu peran vegetasi untuk mengendalikan lingkungan termal adalah
melalui mekanisme evapotranspiation (proses penguapan air dari daun ke
udara) yang dapat mempercepat pendinginan permukaan daun yang juga
berakibat pada penurunan temperatur udara.
Pengukuran terhadap proses evapotranspiration pernah dilakukan oleh
DOE Lawrence Berkeley National Laboratory dan dilaporkan bahwa pohon
berdiameter 30 feet dapat melepas air sebanyak 40 galon / hari.
Pohon dan tanaman mendinginkan udara dengan cara membayangi dan
mungurangi jumlah sinar matahari yang mencapai tanah. Jumlah sinar
matahari yang menembus canopy dinyatakan dalam nilai transmitansi1
yang bervariasi dari 0 – 100%.
Nilai 0 berarti sinar matahari sama sekali tidak dapat menembus canopy, 71
nilai 100 berarti tidak ada sinar matahari yang ditahan oleh canopy.
Journal of Arid Environments
Rain-water management for tree planting in the Indian desert.
Gupta, G. N.
Arid Forest Research Inst., Division of Forest & Desert Development, New
Pali Road, Jodhpur 342005, Rajasthan, India.
The influence of different systems of water harvesting and moisture
conservation on soil moisture storage, growth, biomass accumulation
and nutrient uptake by Azadirachta indica (neem), Tecomella undulata
(rohida) and Prosopis cineraria (khejri) was studied in Rajasthan, India,
The ridge and furrow method of water harvesting was found to be the
best treatment and significantly improved the growth of all 3 species
(height by 58%, 35% and 40%, collar circumference by 73%, 56% and
63%, and crown diameter by 111%, 51% and 131%, respectively).
Biomass accumulation by A. indica and T. undulata increased 3.8-fold and
4.6-fold and root mass 4.5-fold and 3.8-fold, respectively. The mulching
treatment was beneficial to A. indica and weeding treatment to all the 3
Tree roots in water harvesting plots were deeper and had a
spread several times larger than the control. Nutrient uptake by
these tree species increased several-fold as a result of the
different water harvesting and moisture conservation
Peranan vegetasi pohon
Economic Benefits of Tree
Individual trees and shrubs have value, but the variability of species, size, condition,
and function makes determining their economic value difficult. The economic
benefits of trees can be both direct and indirect. Direct economic benefits are
usually associated with energy costs. Air-conditioning costs are lower in a tree-
shaded home. Heating costs are reduced when a home has a windbreak. Trees
increase in value from the time they are planted until they mature. Trees are a wise
investment of funds because landscaped homes are more valuable than
nonlandscaped homes. The savings in energy costs and the increase in property
value directly benefit each home owner.
The indirect economic benefits of trees are even greater. These benefits are
available to the community or region. Lowered electricity bills are paid by customers
when power companies are able to use less water in their cooling towers, build
fewer new facilities to meet peak demands, use reduced amounts of fossil fuel in
their furnaces, and use fewer measures to control air pollution. Communities also
can save money if fewer facilities must be built to control storm water in the region.
To the individual, these savings are small, but to the community, reductions in these
expenses are often in the thousands of dollars.
Plant and Soil
Effects of changes in tree species composition on water flow
dynamics - model applications and their limitations.
Armbruster, M., Seegert, J., Feger, K. H.
Institute of Soil Science and Site Ecology, Dresden University of Technology, 01735
Editors: Hüttl, R. F., Bens, O.
Water-plant relations play a key role in the water cycling in terrestrial ecosystems.
Consequently, changes in tree species composition may have distinct effects on the
water retention capacity as well as on the pattern of streamflow generation. Such
changes may result from modified interception properties and transpiration related to
differences in canopy properties and root distribution. In order to evaluate the
potential hydrological effects of the current silvicultural conversion from monocultural
conifer stands into mixed or pure deciduous stands the hydrological model BROOK90
was applied to two forested upland catchments in Germany. The Rotherdbach
catchment (9.4 ha, 93 yr-old Norway spruce) is situated in the Eastern Ore Mountains.
The Schluchsee catchment (11 ha, 55-yr-old Norway spruce) is located in the higher
altitudes of the Black Forest.
The calibrated model is capable to describe rather well the temporal variation of
streamflow but also the portions of the individual flow components. Data for a beech
scenario were adapted for each site using a standard parameter set for deciduous
trees provided by BROOK90. The annual discharge in the fictional beech stand at
Rotherdbach is 30 to 50% higher compared to spruce with an increase of soil moisture
and especially the slow streamflow components. This mainly results from low
interception rates during winter time. In contrast, the spruce stand has a permanently
higher interception rate. Effects of tree species conversion are moderate at
The annual discharge of a fictional beech stand at Schluchsee is 7 to 14% higher
compared to spruce. There in contrast to Rotherdbach, effects of tree species
conversion on soil moisture dynamics are small since vertical percolation in the
highly permeable soil dominates and precipitation is abundant. Practical forestry will
favorably establish mixed beech-spruce rather than pure beech stands. However, it is
critical to simulate mixed stands with BROOK90. Therefore, a simple summation of
model results from spruce and beech according to their respective area in a fictional
mixed stand can only be a first approximation.
Advanced hydrological simulation of mixed stand conditions should regard
interactions of tree species and spatial parameter distribution. However, this is not yet
feasible due to a distinct lack of information. As a consequence, there is a strong need
to collect relevant hydrological and ecophysiological data in mixed stands in the
Infiltration is governed by two forces: gravity and capillary action. While
smaller pores offer greater resistance to gravity, very small pores pull
water through capillary action in addition to and even against the force
The rate of infiltration is affected by soil characteristics including ease of
entry, storage capacity, and transmission rate through the soil. The soil
texture and structure, vegetation types and cover, water content of the
soil, soil temperature, and rainfall intensity all play a role in controlling
infiltration rate and capacity. For example, coarse-grained sandy soils
have large spaces between each grain and allow water to infiltrate
Vegetation creates more porous soils by both protecting the soil from
pounding rainfall, which can close natural gaps between soil particles,
and loosening soil through root action. This is why forested areas have
the highest infiltration rates of any vegetative types.
Infiltration is the process by which water on the ground
surface enters the soil. Infiltration rate in soil science is a
measure of the rate at which soil is able to absorb rainfall or
irrigation. It is measured in inches per hour or millimeters per
The rate decreases as the soil becomes saturated. If the
precipitation rate exceeds the infiltration rate, runoff will
usually occur unless there is some physical barrier. It is
related to the saturated hydraulic conductivity of the near-
surface soil. The rate of infiltration can be measured using an
Converging patterns of uptake and hydraulic redistribution of
soil water in contrasting woody vegetation types.
Meinzer, F. C., Brooks, J. R., Bucci, S., Goldstein, G., Scholz, F. G., Warren, J. M.
Forestry Sciences Laboratory, USDA Forest Service, 3200 SW Jefferson Way, Corvallis,
OR 97331-4401, USA.
Editors: Meinzer, F. C., Goldstein, G., Phillips, N. G.
We used concurrent measurements of soil water content and soil water
potential (Ψsoil) to assess the effects of Ψsoil on uptake and hydraulic
redistribution (HR) of soil water by roots during seasonal drought cycles
at six sites characterized by differences in the types and amounts of
woody vegetation and in climate.
The six sites included a semi-arid old-growth ponderosa pine (Pinus
ponderosa) forest, a moist old-growth Douglas-fir (Pseudotsuga
menziesii) forest, a 24-year-old Douglas-fir forest, in Washington, USA,
and three Brazilian savanna sites, in Distrito Federal, differing in tree
density. At all of the sites, HR was confined largely to the upper 60 cm of
There was a common threshold relationship between the relative
magnitude of HR and Ψsoil among the six study sites. Below a threshold
Ψsoil of approximately -0.4 MPa, overnight recharge of soil water storage
increased sharply, and reached a maximum value of 80-90% over a range
of Ψsoil from ~-1.2 to -1.5 MPa. Although amounts of water hydraulically
redistributed to the upper 60 cm of soil were relatively small (0 to 0.4 mm
day-1), they greatly reduced the rates of seasonal decline in Ψsoil. The
effectiveness of HR in delaying soil drying diminished with increasing
sapwood area per ground area.
The relationship between soil water utilization and Ψsoil in the 20-60-cm
layer was nearly identical for all six sites. Soil water utilization varied with
a surrogate measure of rhizosphere conductance in a similar manner at all
six sites. The similarities in relationships between Ψsoil and HR, soil water
utilization and relative rhizosphere conductance among the six sites,
suggests that, despite probable differences in maximum rooting depth and
density, there was a convergence in biophysical controls on soil water
utilization and redistribution in the upper soil layers where the density of
finer roots is greatest.
TREE FOR SOIL IMPROVEMENT
The following are the principal trees and shrubs that have been employed for soil
improvement (from Webb et al., 1984; von Carlowitz, 1986; von Carlowitz et al., 1991;
MacDicken, 1994; Young, 1989a, p. 159).
Acacia auriculiformis Acacia cyanophylla Acacia mangium
Acacia mearnsii Acacia nilotica Acacia senegal
Acacia seyal Acacia tortilis Albizia lebbeck
Albizia saman (Samanea saman) Anacardium occidentale
Alnus acuminata Alnus nepalensis Alnus spp.
Atriplex spp. Azadirachta indica Bactris gasipaes
Bamboo genera Cajanus cajan Calliandra calothyrsus
Casuarina cunninghamiana Casuarina equisetifolia
Casuarina glauca Centrosema pubescens Cordia alliodora
Crotalaria spp. Dalbergia sissoo Dactyladenia barteri (Acioa barteri)
Dendrocalamus spp. Erythrina caffra Erythrina orientalis
Erythrina poeppigiana Faidherbia albida (Acacia albida)
Flemingia congesta (Flemingia macrophylla)
Gliricidia sepium Grevillea robusta Inga edulis
Inga jinicuil Leucaena diversifolia Leucaena leucocephala
Melaleuca leucadendron Melia azedarach Musanga cecropioides
Paraserianthes falcataria (Albizia falcataria) Parkia biglobosa (Parkia africana)
Paulownia elongata Peltophorum dasyrrachis
Populus deltoides Prosopis chilensis Prosopis cineraria
Prosopis glandulosa Prosopis juliflora Prosopis tamarugo
Schinus molle Senna reticulata Senna siamea (Cassia siamea)
Senna spectabilis (Cassia spectabilis)
Tree box filters are mini bioretention areas installed beneath trees
that can be very effective at controlling runoff, especially when
distributed throughout the site.1 Runoff is directed to the tree
box, where it is cleaned by vegetation and soil before entering a
catch basin. The runoff collected in the tree-boxes helps irrigate
Tree box filters are based on an effective and widely used ―bioretention or
rain garden‖ technology with improvements to enhance pollutant removal,
increase performance reliability, increase ease of construction, reduce
maintenance costs and improve aesthetics. Typical landscape plants
(shrubs, ornamental grasses, trees and flowers) are used as an integral
part of the bioretention / filtration system. They can fit into any landscape
scheme increasing the quality of life in urban areas by adding beauty,
habitat value, and reducing urban heat island effects.
Manufactured Tree Box Filters For Stormwater Management
(Source: Virginia DCR Stormwater Management Program)
TREE BOX FILTER
The system consists of a container filled with a soil mixture, a
mulch layer, under-drain system and a shrub or tree.
Stormwater runoff drains directly from impervious surfaces
through a filter media.
Treated water flows out of the system through an under drain
connected to a storm drainpipe / inlet or into the surrounding
soil. Tree box filters can also be used to control runoff volumes /
flows by adding storage volume beneath the filter box with an
outlet control device.
Tree Box Filters For Stormwater Management
(Source: Prince George's County, MD Bioretention Manual)