Primate species richness is determined by plant productivity: Implications for conservation

Abstract

The explanation of patterns in species richness ranks among the most important tasks of ecology. Current theories emphasize the interaction between historical and geographical factors affecting the size of the regional species pool and of locally acting processes such as competitive exclusion, disturbance, productivity, and seasonality. Local species richness, or alpha diversity, of plants and primary consumers has been claimed to peak in habitats of low and intermediate productivity, which, if true, has major implications for conservation. Here, by contrast, we show that local richness of Neotropical primates (platyrrhines) is inf luenced by both historical biogeography and productivity but not by tree species richness or seasonality. This pattern indicates that habitats with the highest plant productivity are also the richest for many important primary consumers. We show further that fragmentation of Amazonian rain forests in the Pleistocene, if it occurred, appears to have had a negligible inf luence on primate alpha species richness.Patterns of local animal species richness have been suggested to be causally related to tree species richness, plant productivity, seasonality, habitat heterogeneity, and historical͞ geographical factors (1-5). However, because there are very few sites for which all variables have been measured, the independent effect of these possible causal factors has so far not been assessed. Here, we circumvent this problem by examining the correlations of these variables with an intermediate variable, local rainfall.Previous studies from various tropical regions reported a monotonic increase in richness with rainfall (6-9). However, these studies sampled very few sites with annual rainfall of over 2500 mm and͞or analyzed the relationship using linear regression and were therefore unable to test more complex hypotheses of relationship. We have gathered new data for Neotropical primate richness through a broader range of rainfall levels. Fig.

An exceptional role for flowering plant physiology in the expansion of tropical rainforests and biodiversity

“…The increases in animal diversity with increasing precipitation are probably an indirect consequence of the impact of precipitation on plant diversity and productivity, upon which animal diversity depends more directly (Kay et al 1997;Novotny et al 2006). Since plant epiphytes require frequent and aseasonal rainfall, they would have benefited more directly from the increased precipitation that angiosperms initiated (Boyce 2008), and epiphytic angiosperms, ferns, lycopods and bryophytes all radiated only after angiosperms came to dominate tropical ecosystems (Boyce et al Indeed, numerous lineages of vertebrate and invertebrate animals are also now thought to have radiated shortly after angiosperm diversification (Wang et al 2009), and the propagation of high rainfall conditions by angiosperms provides a potential causal mechanism explaining this phenomenon.…”

A pan-neotropical analysis of hunting preferences

“…However, communities that were close together could have conspicuously different hunting offtake profiles, which implies either that (a) cultural preferences can vary greatly over short distances or that (b) the availability of prey species is highly variable over short distances. Forest productivity is known to vary across the South America with implications for both species richness (Kay et al 1997) and abundance (Emmons 1984;Haugaasen and Peres 2005), but it is difficult to know whether these differences operate on a scale that would account for the differences seen in hunting profiles. Because we could not find any relationship between the age or size of settlements and the three metrics of prey profiles we tested them against (the number of mammal species hunted, the Simpson's diversity index of the prey profile and the average body mass of species hunted) we think it unlikely that the differences seen are a product of some areas starting out with depleted prey availability due to hunting activities.…”

An analysis of the floristic composition and diversity of Amazonian forests including those of the Guiana Shield

“…However, such hypotheses are notoriously difficult to test and often lead to circular reasoning (Tuomisto & Ruokolainen 1997) and in fact may have been based on collector artefacts (Nelson et al 1990). Other evidence suggests that many of the present-day species may have evolved before the Pleistocene climate changes (see examples in Bush 1994, Kay et al 1997.…”