Using plant functional traits to assess ecosystem processes and community dynamics in lowland fens : understanding the efficacy and applicability of a trait-based approach to plant ecology

Carvalho, Fabio and Brown, Kerry A. and Waller, Martyn P. (2017) Using plant functional traits to assess ecosystem processes and community dynamics in lowland fens : understanding the efficacy and applicability of a trait-based approach to plant ecology. PhD thesis, Kingston University.

Abstract

The research presented here focuses on the functional aspect of biodiversity of plant communities, with emphasis placed on the functions of species within biological communities and ecosystems, rather than their identity. The prominence of plant functional traits as major contributors to ecosystem functioning is based on underlying mechanisms whereby individual species interact with each other and with their abiotic environment to influence ecological processes on different spatial scales. In this study, particular attention is given to the modulating effects of functional diversity and composition on community dynamics and ecosystem processes (e.g., soil processes relevant to the cycles of carbon and nitrogen), as well as its response to disturbance. A number of green leaf functional traits considered to be pertinent to soil processes and the biogeochemical cycles of carbon and nitrogen were measured from vascular plant species growing in lowland fens in East Anglia, UK. Such habitats are widely recognised as areas of high conservation value for providing numerous benefits to society, including nutrient cycling and soil carbon storage. The set of analyses presented here reveals the implications of different degrees of management intervention for the functional composition of lowland fen plant communities. Overall, the functional diversity of such communities were found to respond strongly to changing disturbance intensity, to significantly interact with abiotic factors to contribute to the provision of ecosystem processes and to exert major effects on species coexistence within plant assemblages. These results confirm the wide applicability of the trait approach when investigating the effects of biodiversity on the stability of biological communities and ecosystems, and is potentially informative to conservation focused projects that aim to simultaneously enhance biodiversity and the provision of vital ecosystem services. In fact, management intervention was largely found to favour species with a set of traits conducive to enhancing soil carbon storage, lending support to current long term conservation projects that aim to positively influence soil carbon balance.