On the spatial distribution of endemic vascular plants in Valencian Community (Eastern of Iberian Peninsula, Spain). M. GUARA1, E. LAGUNA2 & B. MARTÍN-GARCÍA3 1 Universitat de València, Departament de Botànica, Facultat de Ciències Biològiques, Av. Dr. Moliner, 50, E-46100 Burjassot, València, Spain (E-mail: Miguel.Guara@uv.es). 2 Generalitat Valenciana, Conselleria de Territori i Habitatge, Servei de Conservació i Gestió de la Biodiversitat, C/. Arquitecto Alfaro, 39, E-46010 València, Spain (E-mail: firstname.lastname@example.org). 3 INCARGIS, Av. Pío XII, 60, E-46015 València, Spain (E-mail: email@example.com). Summary The knowledge of the general distribution of endemic, rare and threatened plants populations in the Valencian Community is summarized in a cartographyc way based on 10 x 10 km2 UTM projection, providing the optimization of different tasks in management and research. The data of Valencian endemic plants (exclusive and shared with surrounding regions: plants groups A –58 species– and B –68 species–) are analyzed with SADIE statistical tools combined with GIS software in order to detect areas of plants richness. Two basic areas have been recognized manly related with the two centers of plant diversity described for the Valencian Community. The map generated by this analysis contributes to analyze the importance of criteria A(iii) and A(iv) to select the future IPAs in a regional level. Introduction An Important Plant Area (IPA) is defined as “a natural or semi-natural site exhibiting exceptional botanical richness and/or supporting an outstanding assemblage of rare, threatened and/or endemic plant species and/or vegetation of high botanic value”. It is identified using three basic principles (criteria) concerning with threatened species (A), species richness (B), and threatened habitats (C). Its aim is a site-based approach to conservation. (ANDERSON, 2002). The range of information on plant species distribution and threatened status is variable in European countries and within countries. “Currently there is no central inventory of all the sites that contain Europe’s most threatened plants and habitats or areas of exceptional plant and habitat richness” (ANDERSON, op.cit.). The knowledge of the general distribution of endemic, rare and threatened plants populations in the Valencian Community (Eastern Iberian Peninsula, Spain) is summarized in a cartographic way based on 10 x 10 km2 UTM projection (LAGUNA et al., 1998; SERRA et al., 2000), providing the optimization of different tasks in management and research. Information referred to each UTM unity (territory uses: urban and industry, agrarian and farming, natural vegetation, beaches and dunes, salt marshes, cliffs, aquatic surfaces, and other surfaces; dominant bedrock type: siliceous, calcareous and volcanic; maximum altitude; clinometric average; distance from the coast; bioclimatic indicators: Emberger’s Q Index and minimum temperature average of colder month) has been implemented in a friendly user software based on Windows (GUARA, 2002) in testing period. Based in the compiled information on endemic and near endemic species, criteria A(iii) and A(iv), few areas are considered for future IPAs in a regional level. Methods The data of Valencian endemic plants (exclusive and shared with surrounding regions –near endemics-: plants groups A –58 species– and B –68 species– (SERRA et al, 2000)) are analyzed with SADIE statistical tools (PERRY, 1988; PERRY, et al, 1999) combined with GIS software (ArcView 3.2) in order to detect areas of plants richness. Results and discussion Group A species present two (three) red-basic areas, donor sample units in the sense of Perry et al. (1999), manly related with the two centers of plant diversity described for the Valencian Community, that are consistent with two red-basic areas obtained for group B species. These maps generated by the SADIE analysis shows an important surface in the Valencian territory with capacity for presenting endemic and near-endemic plants (Figure 1). When Group A and B species rich areas are joined, the surface capable of consideration is bigger. The distribution of these two groups of species has a significant overall measure of spatial association (Χ = 0.7137, α < 0.0001), but only a few UTM units have a very significant local association. The highest values of local association indicate the UTM units favorable to be IPA’s in a regional level based on criteria A(iii) and A(iv), but only if these UTM units are “red-areas” (donor sample units) (Figure 2). Considering a 75 % critical value of the local association between Groups A and B, combined with the donor areas of these species groups, the IPAs proposal are located in the S-E Valencian territories (Figure 3). References ANDERSON, S. - 2002 - Identifying Important Plant Areas. Plantlife International - Plantlife, London. www.plantlife.org.uk GUARA, M. - 2002 - Elaboración de un mapa de densidades de flora singular de la Comunidad Valenciana - Convenio de Colaboración entre la Conselleria de Medi Ambient y la Universitat de València. Valencia. LAGUNA, E.; M.B. CRESPO, G. MATEO, S. LÓPEZ-UDIAS, C. FABREGAT, LL. SERRA, J.J. HERRERO- BORGOÑÓN, J.L. CARRETERO, A. AGUILELLA & R. FIGUEROLA - 1998 - Flora endémica, rara o amenazada de la Comunidad Valenciana - Generalitat Valenciana, Conselleria de Medi Ambient. Valencia PERRY, J. - 1998 - Measures of spatial pattern and spatial association for counts of insects - In: BAUMGARTNER, J., P. BRANDMAYR & B.F.J. MANLY (eds.) Population and Comunity Ecology for Insects Management and Conservation: 21-33 - Balkema, Rotterdam. PERRY, J.; L. WINTER, J.M. HOLLAND & R.D. ALSTON - 1999 - Red-blue plots for detecting clusters in count data - Ecology Letters, 2: 106-113. SERRA, LL.; C. FABREGAT, J.J. HERRERO-BORGOÑÓN & S. LÓPEZ-UDIAS - 2000 - Distribución de la Flora Vascular endémica, rara o amenazada en la Comunidad Valenciana - Generalitat Valenciana. Conselleria de Medio Ambiente Acknowledgement The authors thank Dr. J. Perry from IACR-Rothamsted Experimental Station in Harpenden (U.K.) the facilities and assistance in using SADIE software. Figure 1. Red-green-blue maps of Groups A, B and A+B species. Red area is the richest in species. Group A: First red area is oriented in NW-SE between Alicante and Valencia provinces. Second one, is oriented N-S between Castellon and Valencia. A small red area is presented in Castellon. Group B: The two areas detected have similar orientation than the two principal areas of Group A species. Group A+B: Basic two areas detected analysing Group A or Group B appear again. Figure 2. Distribution maps of donor sample units (red). Group A: only one area is resalted, located in SE between Alicante and Valencia provinces. Group B: Different areas are resalted, located in Castellon, Valencia and Alicante provinces. Figure 3. Location map of IPA’s proposal in the Valencian Community. Red-area would be an IPA, between Alicante and Valencia provinces. Blue-area is not relevant for Groups A and B species. Purple-area is the “A+B” species area.