Phenotypic diversity and ecosystem functioning in changing environments: A theoretical framework

TLDR

Biodiversity is essential for ecosystem functioning in changing environments, yet existing theoretical approaches lack a general dynamic theory grounded in mechanistic principles. The authors propose extending quantitative genetics methods to ecosystem functioning by modeling the means and variances of phenotypes within species groups, showing that phenotypic variance within functional groups is linearly related to their ability to respond to environmental changes. They model the aggregate behavior of species groups by estimating the means and variances of phenotypes, linking phenotypic variance to the group’s adaptive response to environmental change. High phenotypic variance can increase long‑term productivity despite short‑term decreases, and under accelerating environmental change species succession may become discontinuous, a phenomenon driven by both diversity and disturbance regimes.

Abstract

Biodiversity plays a vital role for ecosystem functioning in a changing environment. Yet theoretical approaches that incorporate diversity into classical ecosystem theory do not provide a general dynamic theory based on mechanistic principles. In this paper, we suggest that approaches developed for quantitative genetics can be extended to ecosystem functioning by modeling the means and variances of phenotypes within a group of species. We present a framework that suggests that phenotypic variance within functional groups is linearly related to their ability to respond to environmental changes. As a result, the long-term productivity for a group of species with high phenotypic variance may be higher than for the best single species, even though high phenotypic variance decreases productivity in the short term, because suboptimal species are present. In addition, we find that in the case of accelerating environmental change, species succession in a changing environment may become discontinuous. Our work suggests that this phenomenon is related to diversity as well as to the environmental disturbance regime, both of which are affected by anthropogenic activities. By introducing new techniques for modeling the aggregate behavior of groups of species, the present approach may provide a new avenue for ecosystem analysis.