PLANT FUNCTIONAL MARKERS CAPTURE ECOSYSTEM PROPERTIES DURING SECONDARY SUCCESSION

TLDR

Plant community structure and composition influence ecosystem functioning, but a consensus on functional description remains lacking. The study tested the biomass ratio hypothesis in a vineyard abandonment succession and proposed functional markers to evaluate community change impacts on ecosystem properties. Three measurable leaf traits—specific leaf area, leaf dry matter content, and nitrogen concentration—were used to scale organ-level traits to ecosystem-level functioning. Net primary productivity, litter decomposition, and soil carbon and nitrogen varied with field age and correlated with community‑aggregated leaf traits, supporting the use of functional markers.

Abstract

Although the structure and composition of plant communities is known to influence the functioning of ecosystems, there is as yet no agreement as to how these should be described from a functional perspective. We tested the biomass ratio hypothesis, which postulates that ecosystem properties should depend on species traits and on species contribution to the total biomass of the community, in a successional sere following vineyard abandonment in the Mediterranean region of France. Ecosystem-specific net primary productivity, litter decomposition rate, and total soil carbon and nitrogen varied significantly with field age, and correlated with community-aggregated (i.e., weighed according to the relative abundance of species) functional leaf traits. The three easily measurable traits tested, specific leaf area, leaf dry matter content, and nitrogen concentration, provide a simple means to scale up from organ to ecosystem functioning in complex plant communities. We propose that they be called "functional markers," and be used to assess the impacts of community changes on ecosystem properties induced, in particular, by global change drivers.