Tropical Forest Carbon, Habitat Structure, And Faunal Biodiversity: Implications For Conservation

Tropical forests are critical ecosystems for biodiversity, carbon storage and climate regulation, but ongoing forest clearance and the uncertain impacts of climate change pose significant risks to these ecosystems. Deforestation and forest degradation are responsible for about 15% of greenhouse gas (GHG) emissions globally and in some countries, including Indonesia, are the main source of GHGs. Carbon fluxes in tropical forests are large, but uncertainty remains as to the current state and future trajectory of the carbon balance of these ecosystems. Long-term records of biomass are critical for understanding trends and drivers of ecosystem carbon dynamics and their relationship with important conservation metrics, but such datasets are rare. Satellite data is now widely used to study forest biomass over larger spatial scales, and the increasing length of these records enables the study of temporal dynamics as well. However, ground-truth data is essential for the validation of satellite measurements and associated estimates of carbon stocks.
For the last twelve years, Operation Wallacea have been monitoring forest growth through extensive stem diameter measurements at three sites on Buton Island, Indonesia (Harrison et al 2019). Buton Island is a part of the Sulawesi island group and is located in Wallacea, a distinctive biogeographical region that marks the transition from South-east Asia to Australasia (Supriatna 2017). Wallacea is rich in biodiversity but is particularly notable for very high levels of faunal endemism: upwards of 40% of birds and 90% of (land-based) mammals (Martin 2017). Sulawesi is an ecoregion of high global conservation importance due to its high endemism, which is also related to its complex geology, but remains poorly studied. The monitoring sites are located within large tracts of tropical lowland limestone karst forest, one of the more endangered forest types of the region, but to date this data set has not been interrogated in great detail (Cannon et al 2007). In addition to the tree growth data, faunal biodiversity data has been collected from the sites, providing a unique opportunity to investigate relationships between ecosystem carbon and conservation metrics of biodiversity and endemism. This project will involve analysis of existing Operation Wallacea datasets, satellite data and field measurements to investigate factors influencing tropical forest carbon dynamics, as well as explore novel relationships between habitat structure, biodiversity and endemism.