02667nas a2200277   4500008004100000020004600041245008600087210006900173260001100242300001100253490000800264520181000272653001502082653002802097653002502125653001202150653001702162653002302179653003302202653002302235653003102258653001802289100001102307700002002318856005102338       2011                        eng d  a1476-4687 (Electronic)0028-0836 (Linking)00aSpecies-area relationships always overestimate extinction rates from habitat loss0 aSpeciesarea relationships always overestimate extinction rates f  cMay 19  a368-710 v4733 a<p>Extinction from habitat loss is the signature conservation problem of the twenty-first century. Despite its importance, estimating extinction rates is still highly uncertain because no proven direct methods or reliable data exist for verifying extinctions. The most widely used indirect method is to estimate extinction rates by reversing the species-area accumulation curve, extrapolating backwards to smaller areas to calculate expected species loss. Estimates of extinction rates based on this method are almost always much higher than those actually observed. This discrepancy gave rise to the concept of an &#39;extinction debt&#39;, referring to species &#39;committed to extinction&#39; owing to habitat loss and reduced population size but not yet extinct during a non-equilibrium period. Here we show that the extinction debt as currently defined is largely a sampling artefact due to an unrecognized difference between the underlying sampling problems when constructing a species-area relationship (SAR) and when extrapolating species extinction from habitat loss. The key mathematical result is that the area required to remove the last individual of a species (extinction) is larger, almost always much larger, than the sample area needed to encounter the first individual of a species, irrespective of species distribution and spatial scale. We illustrate these results with data from a global network of large, mapped forest plots and ranges of passerine bird species in the continental USA; and we show that overestimation can be greater than 160%. Although we conclude that extinctions caused by habitat loss require greater loss of habitat than previously thought, our results must not lead to complacency about extinction due to habitat loss, which is a real and growing threat.</p>
10a*Ecosystem10a*Extinction, Biological10a*Models, Statistical10aAnimals10aBiodiversity10aModels, Biological10aPasseriformes/classification10aPopulation Density10aTrees/growth & development10aUnited States1 aHe, F.1 aHubbell, S., P.  uhttps://xianhuflora.myspecies.info/en/node/19601832nas a2200289   4500008004100000020004600041245007600087210006900163260001000232300001000242490000800252520094800260653001801208653001201226653003801238653002301276653002301299653002801322100002101350700002101371700002101392700001801413700001901431700002101450700002001471856005101491       2006                        eng d  a1476-4687 (Electronic)0028-0836 (Linking)00aGlobal tests of biodiversity concordance and the importance of endemism0 aGlobal tests of biodiversity concordance and the importance of e  cMar 9  a212-40 v4403 aUnderstanding patterns of biodiversity distribution is essential to conservation strategies, but severe data constraints make surrogate measures necessary. For this reason, many studies have tested the performance of terrestrial vertebrates as surrogates for overall species diversity, but these tests have typically been limited to a single taxon or region. Here we show that global patterns of richness are highly correlated among amphibians, reptiles, birds and mammals, as are endemism patterns. Furthermore, we demonstrate that although the correlation between global richness and endemism is low, aggregate regions selected for high levels of endemism capture significantly more species than expected by chance. Although areas high in endemism have long been targeted for the protection of narrow-ranging species, our findings provide evidence that endemism is also a useful surrogate for the conservation of all terrestrial vertebrates.10a*Biodiversity10aAnimals10aConservation of Natural Resources10aModels, Biological10aPopulation Density10aVertebrates/*physiology1 aLamoreux, J., F.1 aMorrison, J., C.1 aRicketts, T., H.1 aOlson, D., M.1 aDinerstein, E.1 aMcKnight, M., W.1 aShugart, H., H.  uhttps://xianhuflora.myspecies.info/en/node/200