Elevational patterns of species richness and endemism for some important taxa in the Hengduan Mountains, southwestern China

Abstract

We describe the elevational patterns of species richness and endemism of some important taxa in the Hengduan Mountains, southwest China. Species richness data came from publications, an online database, herbaria and Weld work. Species richness was estimated by rarefaction and interpolation. The Hengduan Mountains region was divided into a southern and northern subregion, and all species were assigned to four groups based on their distributional range within this region. The conditional autoregressive model (CAR) was used to relate species richness and explanatory variables. The elevational patterns of total, endemic and non-endemic species richness, at subregion and entire region scales, presented to be unimodal and peaked at similar elevations. Area size was strongly related with species richness, and was more powerful in explaining variation in species richness in the northern subregion than in the southern subregion. A single climatic variable (mean annual rainfall, potential evapotranspiration or moisture index) showed a weak relationship with the elevational pattern of species richness. Area and climatic variables together explained more than 67% of the variation in non-endemic richness, 53% in total richness, and 50% in endemic richness. There were three patterns of endemism at the generic level with increasing elevation: namely endemism increased, decreased, or peaked at middle elevations. All selected taxa have experienced rapid speciation and evolution within this region, which Electronic supplementary material The online version of this article (700 Biodivers Conserv (2009) 18:699-7161 C plays an important role in the uniform elevational patterns of total, endemic and nonendemic richness, and in the multiform elevational patterns of endemism.

Plants are more likely to be spiny at mid‐elevations in the Qinghai‐Tibetan Plateau, south‐western China

“…Previous studies conducted in this area had already found that the highest plant richness occurred at mid-elevationsZhang e al., 2009; but seeBhatta et al, 2018). Previous studies conducted in this area had already found that the highest plant richness occurred at mid-elevationsZhang e al., 2009; but seeBhatta et al, 2018).…”

Explaining the species richness of birds along a subtropical elevational gradient in the Hengduan Mountains

“…3a). Zhang et al (2008) found that richness patterns of total, endemic and non-endemic plant species were unimodal and peaked at high elevations (3500-4500 m); plant species richness was strongly related to area and weakly correlated with precipitation. Other recent studies in the Hengduan Mountains have documented the species richness patterns for plants, insects, reptiles and mammals (Gong et al, 2005;Fu et al, 2007;Zhang et al, 2008;Li et al, 2009;Wu et al, 2013), which revealed a hump-shaped pattern with maxima occurring at different elevations along the elevational gradient.…”

“…Different elevational richness patterns have been reported from different taxa, e.g. Previous studies focusing on species richness patterns in mammals, reptiles, fish and plants along the elevational gradient in the Hengduan Mountains (China) demonstrated that species richness patterns differ widely among life forms, and the corresponding explanations are also diverse and controversial (Fu et al, 2006(Fu et al, , 2007Wang et al, 2007;Zhang et al, 2008;Li et al, 2009;Wu et al, 2013). Rahbek (1995Rahbek ( , 2005 documented that patterns of species richness along elevational gradients can generally be classified into four forms: monotonically decreasing richness with elevation, low-elevation richness plateaux followed by a decrease with elevation, lowelevation plateaux with mid-elevation richness peaks, and unimodal mid-elevational peaks.…”

Elevational Gradient of Vascular Plant Species Richness and Endemism in Crete – The Effect of Post-Isolation Mountain Uplift on a Continental Island System

“…Analogous to species richness-elevation relationships, two main patterns of endemic species richness-elevation relationships have been documented, i.e. increasing [13]–[15] and unimodal [11], [16], [17]. The increase of endemism with elevation has been attributed to the increased isolation of higher elevations.…”

“…Previous studies have mainly been focused on the large mountain massifs of the world [11], [12], [14], [15], [17], [25]–[30] and on tropical islands [31]–[35]. Moreover, the combined effect of island and mountain isolation in the formation of elevational gradient patterns of species richness and endemism of island biota has received little attention.…”