The importance of seed-dispersing animals for forest recovery

• Applicants: Privatdozentin Dr. Eike Lena Neuschulz; Privatdozent Dr. Matthias Schleuning; Professor Dr. Marco Tschapka
• Subject Area: Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 444827997

Seed dispersal by animals plays a pivotal role for tropical forest recovery, making our subproject a central component of the Research Unit. During phase 1, we collected comprehensive data on seed-dispersal interactions involving birds, bats, primates, and ground-dwelling animals. Our findings revealed that these interactions can recover to levels comparable to old-growth forests within approximately two decades. However, the responses of different animal seed dispersers varied, due to an interplay between the locally available resources and the surrounding landscape context. In phase 2, SP4 will investigate seed dispersal by various animal groups using a combination of observational and experimental approaches to identify factors limiting animal-mediated seed dispersal. First, we will resurvey interactions between seed-dispersing animals and fleshy-fruited plants to assess how their interaction networks have changed since the initial surveys. Specifically, we aim to test how the resilience of seed-dispersal interactions differs among animal groups and is influenced by the landscape context (e.g., proximity to old-growth forests). We hypothesize that predictive models may underestimate the resilience of seed dispersal in areas near old-growth forests while overestimating resilience at more isolated sites. Second, we will quantify seed-dispersal potential by measuring seed rain under varying local environmental conditions and landscape contexts. To attract seed dispersers to regenerating forests, we will experimentally deploy artificial perches for birds and roosts for bats, assessing their potential to enhance natural recovery processes. Third, feeding experiments will be conducted examine the ability of different animal groups to access open habitats and facilitate forest recovery. We hypothesize that installing artificial bird perches, bat roosts, and feeding stations will enhance both the taxonomic and functional diversity of seed-dispersing animals, thereby increasing the diversity of seed rain into regenerating forests. By integrating trait-based approaches with observational and experimental methods, SP4 will significantly advance understanding of natural forest recovery facilitated by animal-mediated seed dispersal. Furthermore, it will identify key limiting factors for different animal groups and provide actionable insights for practitioners involved in forest restoration programs.

• DFG Programme: Research Units
• Subproject of: FOR 5207: Reassembly of species interaction networks – Resistance, resilience and functional recovery of a rainforest ecosystem
• International Connection: Ecuador
• Cooperation Partners: Santiago Burneo; Professor Boris Tinoco, Ph.D.