Cover Caption

Cover : Our Lord's candle (Yucca whipplei) occurs in southern California (U.S.A.) and the southwestern Mojave Desert. Several subspecies are restricted to particular geographic locations or floristic provinces. On pages 672‐679, Ferreira and Boldrini review the history of the concept of endemism as it applies to plants. They emphasize that lack of standardization of the geographic extent of endemism complicates classification of species as endemic. On pages 708‐715, Geyer et al. present a method of classifying stresses from climate change that affect different levels of biological organization. Probabilities of persistence of endemic taxa are expected to be highly affected by climate change. Cover image © 2011 Tim Laman. Photographer : Tim Laman ( http://www.TimLaman.com ) is a field biologist and wildlife photojournalist with a Ph.D. from Harvard University. Since 1987, the focus of his scientific research and photography has been the rainforests of Borneo and the Asia‐Pacific region. He is a regular contributor to National Geographic and has published 18 articles in that magazine on topics ranging from endangered species to regions of high species richness under intense pressure from human activities. Tim has also published more than a dozen scientific articles related to rainforest ecology and ornithology. He has a reputation for successfully capturing elusive and critically endangered species in his photographs.