Disturbance alters transience but nutrients determine equilibria during grassland succession with multiple global change drivers

Abstract

Disturbance and environmental change may cause communities to converge on a steady state, diverge towards multiple alternative states or remain in long-term transience. Yet, empirical investigations of successional trajectories are rare, especially in systems experiencing multiple concurrent anthropogenic drivers of change. We examined succession in old field grassland communities subjected to disturbance and nitrogen fertilization using data from a long-term (22-year) experiment. Regardless of initial disturbance, after a decade communities converged on steady states largely determined by resource availability, where species turnover declined as communities approached dynamic equilibria. Species favoured by the disturbance were those that eventually came to dominate the highly fertilized plots. Furthermore, disturbance made successional pathways more direct revealing an important interaction effect between nutrients and disturbance as drivers of community change. Our results underscore the dynamical nature of grassland and old field succession, demonstrating how community properties such as diversity change through transient and equilibrium states.

Nothing lasts forever: Dominant species decline under rapid environmental change in global grasslands

“…However, when disturbances overlap with perturbations, disturbances can eliminate any such lag, also interrupting system hysteresis and causing systems under pressure from global changes factors to rapidly approach new system equilibria (DeSiervo et al, 2023;Ratajczak et al, 2018). Absent from disturbance, we demonstrate that in global grasslands, the degree of dominance and lifespan of species differently influence the maintenance of dominance in current and future grasslands.…”

Contrasting patterns of community-weighted mean traits and functional diversity in driving grassland productivity changes under N and P addition

“…Both N and P, play critical roles in improving community functions and accelerating the grassland restoration process ( Rowe et al., 2006 ; Vitousek et al., 2010 ; DeSiervo et al., 2023 ). In the past decades, some studies have looked into how fertilization affects species interaction and biodiversity to understand the ecological functions of grasslands under various nutrient levels in the Loess Plateau and to develop management practices to improve the restoration process ( Wang et al., 2014 ; Chen et al., 2021 ; Yang et al., 2022b ).…”