Changes in the functional features of macrophyte communities and driving factors across a 70-year period

Marja Lindholm,Janne Alahuhta,Heikki Toivonen,Jan Hjort,Jani Heino

doi:10.1007/s10750-019-04165-1

Marja Lindholm, Janne Alahuhta + Show 3 more

Open Access

https://doi.org/10.1007/s10750-019-04165-1

Copy DOI

Abstract

Functional homogenisation occurs across many areas and organism groups, thereby seriously affecting biodiversity loss and ecosystem functioning. In this study, we examined how functional features of aquatic macrophytes have changed during a 70-year period at community and species levels in a boreal lake district. At the community level, we examined if aquatic macrophyte communities showed different spatial patterns in functional composition and functional richness in relation to main environmental drivers between the time periods. We also observed each species in functional space to assess if species with certain sets of traits have become more common or rare in the 70-year study period. We found changes in the relationship between functional community composition and the environment. The aquatic macrophyte communities showed different patterns in functional composition between the two time periods, and the main environmental drivers for these changes were partly different. Temporal changes in functional richness were only partially linked to concomitant changes in the environment, while stable factors were more important. Species’ functional traits were not associated with commonness or rarity patterns. Our findings revealed that functional homogenisation has not occurred across these boreal lakes, ranging from small oligotrophic forest lakes to larger lakes affected by human impacts.

Highlights

The ongoing biodiversity loss due to human actions is an undeniable crisis (IPBES, 2019; IUCN, 2019)
Our findings revealed that functional homogenisation has not occurred across these boreal lakes, ranging from small oligotrophic forest lakes to larger lakes affected by human impacts
We studied if changes in functional richness in time are linked to concomitant changes in the environment

Summary

Introduction

The ongoing biodiversity loss due to human actions is an undeniable crisis (IPBES, 2019; IUCN, 2019). Habitat degradation and introduction of invasive species to ecosystems are among the main causes of biodiversity loss (IPBES, 2019). One consequence of these anthropogenic changes is biotic homogenisation, a process where ecosystems lose their biological uniqueness, and similarity among communities increases (McKinney & Lockwood, 1999; Olden & Rooney, 2006). Contrary to this process, there is biotic differentiation, where similarity among communities decreases (Olden & Poff, 2003). Most studies have focused only on taxonomic homogenisation and differentiation, while functional and genetic aspects have received less attention (Olden et al, 2018; for definitions, see Table 1)

Objectives

Methods

Results

Discussion

Conclusion