This study addresses key questions in ecology and advances our understanding how human-driven climate change, landscape degradation, and biodiversity loss affect forest resilience and succession. The insights can be applied to (1) reduce human impacts on tropical forests, (2) design resilient and multifunctional tropical landscapes, and (3) design effective forest restoration strategies.
● A NATURE-BASED SOLUTION FOR GLOBAL TARGETS. Given the local and global importance of secondary forests and their rapid recovery after 20 years (on average 78%, range 33-100%) under suitable social,
economic and environmental conditions, we encourage adoption of (assisted) natural regeneration as a low-cost, nature-based solution ecosystem restoration, climate change mitigation, and biodiversity
conservation. This allows to meet the goals of the United Nations’ sustainable development, the UN decade of Ecosystem Restoration (2020-2030), UN framework on climate change mitigation (COP 26), and the
Convention of Biological Diversity (COP 15).
● A MIX OF RESTORATION APPROACHES IS NEEDED. We recommend to preserve all old-growth forests as little is left, use natural regrowth where you can, and plant where you need to.
● THREE SIMPLE INDICATORS TO MONITOR FOREST RESTORATION SUCCESS. Maximum tree size, forest structural heterogeneity (that is, a large variation in tree sizes), and tree species richness are relatively easy to
measure and robust indicators of multidimensional recovery (Poorter et al. 2021 Science).
● DRY AND WET FORESTS REQUIRE DIFFERENT SPECIES FOR RESTORATION. Early successional tree species in wet and dry forests differ markedly in their traits; wet forests have traits that increase growth rates in a
productive, wet, environment whereas dry forests have traits that allow trees to avoid, delay, or tolerate drought in a seasonally dry environment (Poorter et al. 2021 Proceedings of the National Academy of
Scienses). Hence, species selection for active restoration should be fined-tuned to local site conditions.
● A CENTURY OF SUCCESSIONAL THEORIES. We reviewed 100 years of successional studies and 19 successional theories (Poorter et al. 2023 Biological Reviews). Successional theories have increased in scale and scope (from patch
and plant to ecosystems, landscapes, and socio-ecological systems), reflecting the increasingly broader perspective on succession over time.
● A COMPREHENSIVE SUCCESSIONAL FRAMEWORK. We present a framework to analyse in a standardized way succession across the globe, and to get a better insight in the relevant successional processes and the underling drivers
and mechanisms (Poorter et al. 2024 Ecosphere).
