Dung beetles are an ecologically important insect taxa providing many ecosystem functions and services, such as nutrient cycling, soil aeration, and secondary seed dispersal (check out the video below). They are also an excellent model taxon for biodiversity research as they respond rapidly to environmental changes and can be sampled cost-effectively. We are using an integrative approach combining ecological, molecular, and evolutionary methods to document the impacts of land-use and climate change on the dung beetles of Southeast Asia.
We combine data on species morphological, behavioural, and physiological traits, with data on species abundances, composition, and associated ecosystem functions across land use gradients. This allows us to predict how species will respond to land use change, climate change, and the distributions of mammals, and the consequences for ecosystem functioning. We are also using population genomics and manipulative experiments to study genetic differences across habitats, the response of species to temperature manipulations, and barriers to gene flow in human-modified environments.
Accurate information on the taxonomy and distribution of the dung beetles in Southeast Asia is currently lacking. With collaborators in the ReproLab at NUS, we are building a database of species distributions and traits for the dung beetles of Malaysia and Singapore, and a guide to the dung beetles of lowland Sabah. Eventually, we hope that this database will be expanded, and will serve as an open access resource on Southeast Asian dung beetles, which will assist in reducing the taxonomic impediments that currently exist for dung beetle research in the region.
Despite many studies on the impacts of habitat degradation and modification on diversity in tropical forests, the cascading functional consequences of these anthropogenic changes remain poorly understood. Thus, while the majority of research has focused on species as the unit of biodiversity loss, an overlooked component of biodiversity loss is the extinction of ecological interactions. These are important as they often accompany or precede the loss of species, and may have direct effects for ecosystem functionality.
We have been building the first interaction networks linking dung beetles and mammals and investigating how these networks change across a land-use gradient from forest to oil palm plantations. With these networks, we will test fundamental ideas about the consequences of species extinctions for ecological interactions and the cascading effects on ecosystem processes.
Biodiversity & Ecosystem Functioning
We are interested in understanding how ecological diversity and functioning are affected in human-modified landscapes, and use surveys along habitat modification gradients to detect patterns, combined with manipulative field experiments, to gain a mechanistic understanding of ecological interactions and biodiversity-function linkages.
With our collaborators, we have developed new approaches to measuring species interactions on ecosystem multifunctionality in terrestrial animal systems, and shown that optimising multifunctionality is context-dependent and contingent upon how ecosystem services are valued.
Habitat Fragmentation & Connectivity
The lack of high-resolution data on movements and dispersal of many invertebrate species is hindering our ability to predict the consequences of loss of both species, and interactions among species, under changing environmental conditions. We are interested in the landscape-scale implications of fragmentation, and how species use fragmented forest patches and connectivity 'corridors' to disperse and move across human-modified landscapes. In Singapore, we are researching ways to restore connectivity in urban landscapes, with a focus on invertebrates that provide important ecosystem functions and services (e.g. pollination, decomposition, nutrient recycling). We also study the effects of logging and conversion to oil palm and the importance of protected areas for invertebrates, and the ecosystem functions and services they provide.
We have been working with the Roundtable of on Sustainable Oil Palm (RSPO), the South East Asian Rainforest Research Partnership (SEARRP) and the Sabah State Government of Malaysia to contribute to the development of policy and best practices in the oil palm industry, and among government agencies engaged with land-use planning in Sabah, to ensure connectivity remains within the landscapes, and to update guidelines for the management of riparian areas.