Project Details
Projekt
Life after death: litter decomposition as a keystone process in tropical forest recovery
Subject Area
Ecology and Biodiversity of Plants and Ecosystems
Term
since 2025
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 444827997
Decomposition is a keystone process in tropical forest regeneration. Decaying plant litter is a major source of soil carbon and nutrients to support plant growth. The litter layer on the soil surface also limits water loss and erosion, provides habitat space for invertebrates, and can help or hinder seed germination. Reduced litter inputs after deforestation therefore disrupts many crucial ecosystem processes and affects soil health. These impacts are more severe in open sites such as pastures, because decomposition is hindered by the hotter, drier microclimate and losses of soil animals. Consequently, the combined effects of biodiversity loss, reduced litter inputs, and harsh microclimate dramatically reduce soil health after forest conversion to pasture. Reactivating decomposition processes is key to reversing the decline in soil health, thus providing the foundation for forest regrowth. The aim of this project is therefore to identify the role of decomposition in forest regeneration success. Our project will achieve this aim through three experiments that each address a different aspect of change during forest regrowth. First, changes in tree species composition could affect soil health and diversity via differences in litter decay rates. We will test this by measuring the decay of leaf litter from different tree types along a forest regeneration gradient (from recent pasture to old established forest). In addition, we will determine whether ‘remnant’ trees – old forest trees remaining in pasture sites – could accelerate the recovery of soil health by maintaining favourable conditions for decomposition. Second, the litter from different tree species could also influence the establishment of plants during forest regrowth by promoting or hindering seed germination. We will test whether differences in litter decomposition affect germination success and seedling survival in a pot experiment using seeds and leaf litter characteristic of young vs. old forests. Finally, epiphylls – organisms that grow on the surface of leaves – could affect litter decomposition because they have distinct characteristics to their host leaves. Epiphylls grow in the humid understorey of old forests, so their absence during early forest regrowth could affect litter decomposition. We will test this by quantifying differences in the decay rates of leaves with or without epiphylls and measuring their chemical properties. Collectively, these studies will elucidate the importance of decomposition processes for the regeneration of soil health and biodiversity during tropical forest regrowth, which will provide valuable information to support active reforestation projects.
DFG Programme
Research Units
International Connection
Ecuador
Cooperation Partner
Professor Dr. Esteban Suárez
