BoCP-Implementation: Cascading Impacts of Landscape Structure on Forest Regeneration

University Of California-Berkeley, Berkeley CA

Investigators

Abstract

The Earth is undergoing unprecedented environmental changes not seen for millennia including massive transformation of landscapes for agricultural and development expansion and a biodiversity extinction crisis. Recent studies suggest that the regeneration of tropical forests will play a crucial role in mitigating global human-induced environmental change, reducing atmospheric greenhouse gasses, and recovering lost ecosystem functions and services. However, while a large proportion of cleared forests worldwide undergo regeneration, they rarely recover to initial old-growth functions and conditions. The specific mechanisms that underpin this recovery remain uncertain, particularly in landscapes heavily influenced by human activity. This project aims to address this knowledge gap by examining how landscape structure interacts with seed-dispersing animals to influence the regeneration of tropical forests. The study will take place in highly endangered rainforests in Madagascar, which are characterized by complex land-use patterns. The insights gained from this research will have broader implications for identifying different landscape scenarios where forests are more likely to regenerate to old-growth forest conditions, thus contributing to climate change mitigation and biodiversity conservation. To accomplish this, an international, multidisciplinary team will collaborate with local partners, engage undergraduate students from underrepresented groups, and involve artists to provide diverse perspectives and communicate creatively with multiple stakeholders. This project will investigate the direct and indirect effects of landscape structure on trait-mediated seed dispersal in regenerating tropical forests in anthropogenic landscapes. Landscape properties such as habitat amount, fragmentation and matrix quality, are known to modulate several crucial dispersal processes, including seed rain, diversity of seed sources, and diversity of seed dispersers, all of which affect post-dispersal seedling recruitment and the resulting community of regenerating vegetation. These processes can be influenced by plant dispersal traits, such as fruit and seed type, shape, and size. We hypothesize that landscape structure acts directly as an abiotic filter and indirectly as a biotic filter that influences seed diversity in regenerating forests by determining seed availability and seed disperser availability, respectively. Within this framework, the project will address fundamental gaps in knowledge by using an integrated, multi-scale approach that combines measurements of seed community assembly and trait-mediated seed dispersal, predictive modeling, and spatially explicit upscaling to gain insights into how landscape structure influences forest regeneration. Specifically, the researchers will (1) conduct an analysis of seed diversity along successional gradients (chronosequence) of regenerating tropical forests in different landscape contexts; (2) investigate how landscape structure and seed dispersers interact to influence plant diversity in regenerating forests; and (3) use a combination of remote sensing and a spatially explicit agent-based models to derive mechanistic explanations for how landscape structure influences forest recovery at multiple spatial scales. By focusing on arguably the most important stage of regeneration, this project will advance the knowledge of how tropical forest regeneration can be stabilized, delayed, or accelerated according to the landscape context. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.