Infodoc : Sciences, Techniques et Culture

Faced with ongoing land-use pressures in tropical forests, the restoration of degraded forestland has become a necessity to protect species and ensure long-term ecosystem resilience in tropical environment. Despite increased efforts in recent years to restore forests and research the drivers of restoration processes, there remains a significant lack of knowledge about landscape influence on restoration outcomes, particularly in the tropical forests of South and Southeast Asia. This thesis aims to understand the influence of landscape-level factors at multiple scales on dispersal dynamics, functional composition, particularly on shade tolerant species, and tree diversity in spontaneously regenerating forest and actively restored forest in the Western Ghats,India. A functional approach [...]

Faced with ongoing land-use pressures in tropical forests, the restoration of degraded forestland has become a necessity to protect species and ensure long-term ecosystem resilience in tropical environment. Despite increased efforts in recent years to restore forests and research the drivers of restoration processes, there remains a significant lack of knowledge about landscape influence on restoration outcomes, particularly in the tropical forests of South and Southeast Asia. This thesis aims to understand the influence of landscape-level factors at multiple scales on dispersal dynamics, functional composition, particularly on shade tolerant species, and tree diversity in spontaneously regenerating forest and actively restored forest in the Western Ghats,India. A functional approach was adopted to provide a detailed analysis of the filters affecting recovering communities. Our results showed a significant landscape influence at middle and large scales on functional composition, such that more open and fragmented landscapes promoted resistant traits (e.g. low SLA, high WD and high LDMC), contrasting with previous observations of negative influence on traits commonly associated with shade tolerant species.These influences were more pronounced on seedling communities. Landscape influence wasabsent on diversity and almost absent on dispersal traits, with only a negative influenceobserved on large-seeded species at small scales. Finally, active restoration treatmentspromoted resource-conservative traits but simultaneously reduced overall species diversity compared to spontaneous regenerating community. This study challenges the previously held notion of the landscape's negative impact on shade-tolerant species and dispersal dynamics, and points to the potential influence of drought in shaping community composition of recovering forests in the Indian context. The result underscore the potential of spontaneous regeneration where there is no strong signal that elements of the functional community are missing. Spontaneous regeneration may provide an important contribution to upscaling forest restorationefforts across the tropics, especially when there is sufficient remnant forest in the landscape that key ecosystem functions have been maintained