Supervisor
David Edwards
Brief Summary
Most tropical forests have been or soon will be selectively logged. Despite suffering substantial levels of damage, the majority of species remain albeit often at altered abundances. A key question is how logging impacts the longer-term survival of species. Over time, species could remain at altered abundances, they may recover in abundance to old-growth levels, or might decline towards extinction. Since 2014, we have been sampling the avian communities in primary old-growth and intensively selectively logged forests of Borneo using standardized mist-netting approaches. This project will use and expand this long-term field dataset to quantify the impacts of logging and associated changes in habitat quality on avian survival, and in turn, to understand how logging impacts species communities over time.
Importance of Research
Tropical forests comprise ~11% of the terrestrial surface, but harbour ~80% of species globally. At least 400 million hectares of tropical forest are in the permanent timber estate, and either have been or soon will be selectively logged, plus huge additional areas are being illegally selectively logged. The conservation of global biodiversity is thus inextricably linked to how species and communities respond to selective logging and associated changes in habitat quality. It is now well-known that most biodiversity persists within selectively logged forests shortly after timber harvest, underpinned by changes in feeding and movement ecology. A key question is understanding how species and communities respond to selective logging over time. In particular, we do not know how community composition and species co-occurrence changes over time, and in turn, how core demographic vital rates – survival and recruitment – which underpin long-term persistence of species are impacted. The answer to these questions is critical in understanding whether the protection of selectively logged forests from their frequent clearance to agriculture can support global conservation objectives over the long term, or whether we need to renew our focus on protecting remaining tropical old-growth forests.
Project Summary
Selectively logged forests dominate most remaining tropical forests. This PhD will quantify the consequences of selective logging for community composition and species vital rates. It will use and extend a long-term, standardized effort mist-netting dataset, in which birds have been in primary and selectively logged forests of Borneo since 2013 using mark-recapture methods. These data will permit exploration of how community composition, species co-occurrence, and species vital rates are impacted by logging and associated changes in habitat quality over time.
What will the successful applicant do?
- Conduct annual (~3 month) field campaigns of standardized effort mist-netting in Sabah, Malaysian Borneo.
- Quantify how community composition, species co-occurrence, and beta-diversity have changed over time
- Build hierarchical models of species demography to project the impacts of logging on species survival and recruitment.
- Link changes in communities and vital rates to habitat structure (ie severity of logging)
References
Bousfield C, Cerullo GR, Massam MR, Edwards DP (2020) Protecting environmental and socio-economic values of selectively logged tropical forests in the Anthropocene. Advances in Ecological Research 62: 1-52
Cosset CCP, Gilroy JJ, Tomassi S, Benedick S, Nelson L, Cannon PG, Messina S, Kaputa M, Fandrem M, Soto Madrid R, Lello-Smith A, Pavan L, King B, Fogliano R, Hackney-Huck T, Gerald E, Chai J, Cros E, Yao CY, Hong TC, Chai RR, Ong CC,
Edwards DP (2021) Selective logging drives local movement in tropical understorey avian communities. Biological Conservation 264: 109374
Edwards DP, Larsen TH, Docherty TDS, Ansell FA, Hsu WW, Derhé MA, Hamer KC, Wilcove DS (2011) Degraded lands worth protecting: the biological importance of Southeast Asia’s repeatedly logged forests. Proceedings of the Royal Society B 278: 82-90
Edwards DP, Tobias J, Sheil D, Meijaard E, Laurance WF (2014) Maintaining ecosystem function and services in logged tropical forests. Trends in Ecology and Evolution 29: 511-520