Climatic disequilibrium in tree cover is frequent in protected areas worldwide — implications for conservation and restoration

TY - JOUR

T1 - Climatic disequilibrium in tree cover is frequent in protected areas worldwide — implications for conservation and restoration

AU - Schweiger, Andreas Hubert

AU - Svenning, Jens Christian

N1 - Publisher Copyright: © 2024 The Author(s). Journal of Vegetation Science published by John Wiley & Sons Ltd on behalf of International Association for Vegetation Science.

PY - 2024/7

Y1 - 2024/7

N2 - Many species and ecosystems that diversified and adapted under consumer control in prehistoric times are nowadays highly threatened. Nature protection areas (PAs) form a major conservation strategy to avoid their losses. We argue that many PAs across Earth are in disequilibrium with current climatic conditions. At the same time, the main consumers of woody vegetation keeping these systems in climatic disequilibrium, that is, large-bodied herbivores and/or fire, have strongly declined or changed in occurrence in (pre-)historic times. Without active intervention, this lack of consumer control will cause the systems to approach climate equilibrium with major implications for baseline-focused approaches in species and nature protection and restoration. In a global analysis we quantified the prevalence of climatic disequilibrium in PAs for all terrestrial biomes. We calculated climatic disequilibrium in PAs as the difference between actual tree cover and the potential tree cover under current climatic conditions (i.e., mean annual temperature and annual precipitation sum). We show that climatic disequilibrium conditions in tree cover are a widespread phenomenon in PAs across all biomes with highest values for the temperate grassland, tundra and taiga biomes. We argue that trophic rewilding, notably the restoration of functionally diverse large-herbivore assemblages, would not only help maintain climatic disequilibrium states, but also reduce labour and costs for management.

AB - Many species and ecosystems that diversified and adapted under consumer control in prehistoric times are nowadays highly threatened. Nature protection areas (PAs) form a major conservation strategy to avoid their losses. We argue that many PAs across Earth are in disequilibrium with current climatic conditions. At the same time, the main consumers of woody vegetation keeping these systems in climatic disequilibrium, that is, large-bodied herbivores and/or fire, have strongly declined or changed in occurrence in (pre-)historic times. Without active intervention, this lack of consumer control will cause the systems to approach climate equilibrium with major implications for baseline-focused approaches in species and nature protection and restoration. In a global analysis we quantified the prevalence of climatic disequilibrium in PAs for all terrestrial biomes. We calculated climatic disequilibrium in PAs as the difference between actual tree cover and the potential tree cover under current climatic conditions (i.e., mean annual temperature and annual precipitation sum). We show that climatic disequilibrium conditions in tree cover are a widespread phenomenon in PAs across all biomes with highest values for the temperate grassland, tundra and taiga biomes. We argue that trophic rewilding, notably the restoration of functionally diverse large-herbivore assemblages, would not only help maintain climatic disequilibrium states, but also reduce labour and costs for management.

KW - climate change

KW - conservation

KW - green world hypothesis

KW - non-equilibrium

KW - restoration

KW - rewilding

UR - http://www.scopus.com/inward/record.url?scp=85201044679&partnerID=8YFLogxK

U2 - 10.1111/jvs.13298

DO - 10.1111/jvs.13298

M3 - Journal article

AN - SCOPUS:85201044679

SN - 1100-9233

VL - 35

JO - Journal of Vegetation Science

JF - Journal of Vegetation Science

IS - 4

M1 - e13298

ER -