Biodiversity

Seed dispersal strategies and the threat of defaunation in a Congo forest

Background

Seed dispersal is a crucial ecological process that shapes plant communities and maintains biodiversity in tropical forests. In the Congo Basin, most tree species rely on animals (zoochory) to disperse their seeds, with large vertebrates like forest elephants and bonobos playing a key role. However, hunting and poaching threaten these seed dispersers, which could have cascading effects on forest structure and plant regeneration. This study investigates the extent of animal-mediated seed dispersal in the LuiKotale forest, located in the Democratic Republic of the Congo (DRC), and assesses how hunting pressure on frugivores may impact tree community composition.

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Defaunation of Large-Bodied Frugivores Reduces Carbon Storage in a Tropical Forest of Southeast Asia

Background

Tropical forests are vital for carbon storage, but recent studies suggest that defaunation—the loss of large-bodied seed dispersers due to hunting and habitat fragmentation—can significantly impact this function. While previous research has shown reductions in above-ground carbon storage due to defaunation in South America and Africa, its effects on Southeast Asian forests remain debated. Some scientists argue that the dominance of wind-dispersed Dipterocarpaceae trees in the region buffers against carbon losses from defaunation. This study examines the extent to which defaunation influences carbon storage in a tropical forest in Thailand, where large frugivores such as primates, hornbills, and terrestrial mammals still persist.

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Drivers and spatial patterns of avian defaunation in tropical forests

Background

Tropical forests harbor an immense diversity of bird species, but hunting and wildlife trade are driving widespread declines in bird populations. Unlike habitat loss, hunting often occurs in seemingly intact forests, making its impact more difficult to detect. Birds are harvested for both subsistence (food) and commercial purposes (pet trade), but the spatial extent and drivers of avian defaunation remain poorly understood. This study aims to assess the factors influencing bird population declines and map defaunation patterns across tropical forests.

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Using Janzen–Connell to predict the consequences of defaunation and other disturbances of tropical forests

Background

The Janzen–Connell (J–C) model describes how seed dispersal and mortality shape tropical forest diversity. According to the model, seeds that fall close to their parent trees suffer high mortality due to host-specific predators, pathogens, and herbivores. In contrast, seeds dispersed farther away have a better chance of survival. Defaunation, particularly the loss of large-bodied seed dispersers, disrupts this balance by reducing seed dispersal distances. This study applies the J–C model to predict how defaunation and other disturbances affect tree recruitment and forest composition.

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Cascading effects of contemporaneous defaunation on tropical forest communities

Background

Defaunation, caused by hunting and habitat fragmentation, is a major threat to biodiversity in tropical forests. It disproportionately affects large-bodied vertebrates, which play key roles as seed dispersers, seed predators, and herbivores. The loss of these animals can have cascading effects on plant populations, altering species composition, seed dispersal, and plant recruitment. This study reviews empirical evidence from 42 studies to understand how defaunation influences plant-animal interactions, plant demography, and overall community diversity.

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Defaunation affects carbon storage in tropical forests

Background

Tropical forests play a critical role in global carbon storage, holding approximately 40% of the Earth's terrestrial carbon. While deforestation, logging, and climate change are well-documented threats to these forests, the impact of defaunation (the loss of large frugivorous animals due to hunting and habitat loss) has been largely overlooked. Many large-seeded hardwood trees rely on large vertebrates for seed dispersal, and their decline could significantly affect forest composition and carbon storage.

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Active restoration of post-mining forest benefits the activity density, but not the diversity of spider communities across the seasons in Ghana

BACKGROUND:

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Institutional Design of Forest Landscape Restoration in Central Togo: Informing Policy-making through Q Methodology Analysis

BACKGROUND:

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Promises and potentials do not grow trees and crops. A review of institutional and policy research in agroforestry for the Southern African region

BACKGROUND:

Agroforestry has been recognized for its potential to address land management challenges, improve food security, and support rural livelihoods, but its widespread adoption remains limited. Institutional and policy barriers, including weak coordination among sectors and inadequate incentives, hinder its integration into national and local frameworks. Strengthening policies, institutions, and research on the social and economic dimensions of agroforestry is essential for its successful implementation and long-term impact.

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Complementary ecosystem services from multiple land uses highlight the importance of tropical mosaic landscapes

Background

Tropical agricultural landscapes feature a mosaic of diverse land uses, yet the ecosystem service bundles and materials they provide to rural households remain poorly understood. In northeastern Madagascar, shifting cultivation for hillside rice production and agroforests for cash and subsistence crops have largely replaced old-growth forests. The landscape consists of forest fragments, small-scale vanilla agroforests, rice paddies, and subsistence farming plots at various stages of the shifting cultivation cycle.

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