Taxonomic and Functional Ant Diversity Along tropical, Subtropical, and Subalpine Elevational Transects in Southwest China.

Chris J. Burwell,Yong Tang,Min Cao,Zhenghui Xu,Roger L. Kitching,Alyssa M. Fontanilla,Akihiro Nakamura

doi:10.3390/insects10050128

Abstract

Although elevational gradients of biodiversity have long been the topic of scientific research, information on patterns of, and processes that shape insect community structure across elevation is still lacking. Addressing this gap requires the use of both taxonomic and functional approaches when studying diversity across elevational gradients. In this study, we examined taxonomic and functional alpha and beta diversity of ant assemblages sampled along tropical, subtropical, and subalpine elevational transects in Yunnan Province, southwest China. Species richness was used to quantify taxonomic alpha diversity, and two indices (FD and FRic) were calculated using morphological measurements to quantify functional alpha diversity. Taxonomic and functional beta diversity were partitioned into their turnover- and nestedness-resultant components. Though temperature and functional alpha diversity decreased linearly with increasing elevation, taxonomic alpha diversity showed a significant logarithmic decrease, with few species present at elevations greater than 3000 m a.s.l. The turnover-resultant component of taxonomic beta diversity increased with increasing elevational distance, while the nestedness-resultant component of functional beta diversity increased with increasing elevational distance in the subtropical transect. The observed patterns of taxonomic and functional diversity reflected ants’ thermophilic nature, implying functional adaptations (i.e., nested functional diversity) at higher elevations where environmental conditions were unfavorable.

Highlights

The variation of species diversity with latitude and elevation has been the subject of numerous studies for over three centuries, having been mentioned in the scientific literature as early as the late1700s [1] and discussed at the start of the 19th century in more detail by Willdenow [2] and, perhaps most notably, by Humboldt [3]
We examined how taxonomic and functional alpha diversity changed with elevation, whether species composition varied between elevational bands within the same transect, whether taxonomic and functional beta diversity were driven by either turnover or nestedness, and if ant community structure was shaped by either stochastic or deterministic processes
Mengla had the highest percentage of species present in all elevational bands (Mengla: 17%; Ailaoshan: 5%; Lijiang: 0%) and the highest number of species occurring in two adjacent elevational bands (Mengla: 53; Ailaoshan: 13; Lijiang: 1)

Summary

Introduction

The variation of species diversity with latitude and elevation has been the subject of numerous studies for over three centuries, having been mentioned in the scientific literature as early as the late1700s [1] and discussed at the start of the 19th century in more detail by Willdenow [2] and, perhaps most notably, by Humboldt [3]. Productivity appears to have a smaller contribution to the LDG, and the tendency of tropical regions to harbor higher numbers of rare and/or specialized species suggests that niche relationships and the effects of abiotic factors such as temperature on species diversity are more significant [8] Various factors such as productivity, climatic conditions, area, geometric constraints, and source-sink dynamics have been tested as possible mechanisms driving elevational diversity gradients [9], but temperature, which decreases with increasing elevation, has been shown to be one of the best predictors of species richness in elevational diversity gradient studies involving different taxa and biogeographical areas (e.g., [10,11]). Functional diversity is not concerned with systematic relationships among species, and quantifies biodiversity within a given community based on the interspecific variation of traits related to ecosystem functioning [12]

Methods

Results

Conclusion