Functional diversity estimated from species’ traits reflects their morphological, physiological, and ecological roles and their influence on ecosystem functioning and provides a link between species diversity and ecosystem processes. Understanding how functional diversity varies along environmental gradients can help us elucidate the species-trait-environment relationship and the underlying processes governing species communities. Richness-based measures, such as the number of species, have long been used to understand various aspects of global change, such as climate change, land use change, invasive species, etc. However, they do not provide much information about the consequences for ecosystem functioning. Functional trait-based approaches can offer insights into ecosystem functions and the structure of communities. I will use functional diversity and trait-based approaches to understand how ground-dwelling arthropod communities vary across environmental gradients. These ground-dwelling arthropods (ants, beetles, wasps, bees, spiders, ticks and mites, centipedes, collembolans, etc.) offer opportunities to understand biodiversity patterns on how communities can respond to environmental variation.
In the first chapter, I will study how the functional diversity of communities varies along an elevational gradient (from 3700 to 5000 m asl) in the Trans-Himalayas. Here, I will examine diversity patterns in multiple taxa along this gradient that interact with ground-dwelling arthropods (e.g., plants and soil microbial decomposers). In chapter two, I will focus on a subset of species that occur along the entire gradient, i.e., wide elevational distribution. Here, I will examine intraspecific trait variation in this subset of species to determine the characteristics of their trait-and-environment relationships. In chapter three, I will evaluate how invasive species can influence the functional diversity of communities across various land-use types. Here, I will study how Anoplolepis gracilepis (yellow crazy ant)—one of the 100 worst invasive species in the world—affects the community structure of ants. I will also test the trait-similarity hypothesis to ask whether the species that co-exist with the invader are functionally differentiated.
I expect this work will provide insights into how community structure and functions vary across environmental conditions.