Journal of Plant Ecology Advance Access published March 14, 2013 Journal of Plant Ecology Spatial patterns of distribution PAGES 1–10 doi: 10.1093/jpe/rtt014 and abundance of Harrisia available online at www.jpe.oxfordjournals.org portoricensis, an endangered Caribbean cactus Julissa Rojas-Sandoval1,2,* and Elvia J. Meléndez-Ackerman2,3 1 Department of Biology, University of Puerto Rico, Río Piedras Campus, PO Box 23360, San Juan, Puerto Rico 00931-3360, USA 2 Center for Applied Tropical Ecology and Conservation, University of Puerto Rico, PO Box 70377, San Juan, Puerto Rico 00936-8377, USA 3 Department of Environmental Sciences, College of Natural Sciences, University of Puerto Rico, PO Box 70377, San Juan, Puerto Rico 00936-8377, USA *Correspondence address. Department of Botany, National Museum of Natural History, MRC-166, Smithsonian Downloaded from Institution, PO Box 37012, Washington DC 20013–7012, USA. Tel: (001) 520 425 4518; Fax: (001) 202 633 0899; E-mail:
[email protected] Abstract http://jpe.oxfordjournals.org/ Aims Important findings The spatial distribution of biotic and abiotic factors may play a dom- Abundance of H. portoricensis showed strong affinities with micro- inant role in determining the distribution and abundance of plants habitat variables related to canopy structure, soil cover and light in arid and semiarid environments. In this study, we evaluated how environment. The distribution of this cactus species throughout the spatial patterns of microhabitat variables and the degree of spatial island was consistent with the spatial variation patterns of these var- dependence of these variables influence the distribution and abun- iables. In general, landscape-level analyses suggested a predictive by guest on March 15, 2013 dance of the endangered cactus Harrisia portoricensis.