Restoring the rainforests of Borneo
In the Danum Valley of Sabah, in the Malaysian part of the island of Borneo, lies one of the leading rainforest research centers in southeast Asia - the base for an Earthwatch project started by Dr Glen Reynolds in 2008.
The rainforests of southeast Asia support much of the region's biodiversity. They play a crucial role in providing important ecosystem services such as soil stabilization and carbon storage, and are an important source of income locally and nationally. However, these lowland forests are under serious threat from direct and indirect human activities. Deforestation is occurring at a huge rate, due to logging for timber, conversion to huge agricultural plantations, and slash-and-burn farming methods. This has a serious impact on biodiversity and general functioning of the ecosystem and, as a result, affects the livelihoods of the many people who depend on the forests for income, shelter, water and food.
Perhaps the biggest and most long-term threat facing the rainforests, however, is posed by climate change, in particular increasingly severe and frequent droughts associated with El Niño Southern Oscillation (ENSO) events - the dry phase of a global cycle driving our climate. The wet La Niña phase of the ENSO cycle is also becoming more intense, leading to increasing frequency and size of large rainstorms. These wash away huge amounts of soil (and with it, valuable nutrients), which then ends up in the rivers causing sedimentation and flooding downstream.
The most important group of tree species in the rainforests of Borneo are the dipterocarps, which includes some of the largest forest species that grow in the tropics. In fact, Borneo hosts the greatest diversity and abundance of dipterocarps in the world - but they are suffering severely from the threats outlined above. The reduced recruitment of new seedlings and regeneration of older trees could have potentially disastrous implications. The future of the dipterocarps is at risk beyond the current generation unless restorative intervention is carried out.
The goal of the Earthwatch project
In order to reverse rainforest degradation and prevent its further loss, it is essential that degraded areas of forest are restored to maintain biodiversity and ecosystem function, and that we assess and mitigate against the impacts of climate change on the rainforest system and its key components. And this is exactly what the Earthwatch project is doing.
The goal for Dr Reynolds and his team of research scientists is to assess and understand biodiversity, ecosystem functioning, capacity for regeneration and the requirements for restoration in degraded forests and remaining forest fragments.
In the field
The field research focuses firstly on the diversity and functions of trees and plants within the ecosystem. Because almost all animals depend directly or indirectly on plants, the project provides important information on other species as well. Second is a focus on soil moisture and erosion, as both are critical in assessing the likely ecological impacts of climate change on rainforest systems.
Volunteers work with the scientists on assessing regeneration and restoration requirements through planting, measuring seedlings, assessing survival and growth and making habitat assessments in experimental areas within forest fragments, degraded forest and primary forest. Experiments to test regeneration success are carried out by manipulating different levels of seed availability, and studying the rates of seed predation.
To get an idea of the biodiversity that exists in forests experiencing different levels of disturbance, as well as in different sizes of forest patches, expedition teams survey tree species along transects, and assess vegetation structure by looking at the area at the base of trees and how open the canopy is (to find out how much light gets through). The scientists also look at forest fragments in more detail, to understand how they might be able to contribute to sustainable management of plantations such as palm oil by maintaining some of the functions of the rainforest ecosystem and biodiversity. To do this, the scientists study key animal species groups including predators, nectar-eaters, herbivores and pollinators, in fragments and adjacent areas of plantation. They also collect leaf litter and assess the rate of decomposition.
The final area of research aims to establish the resilience of forest fragments and degraded or restored rainforest, in comparison with primary forest, to predicted increases in drought intensity and heavy rainfall associated with climate change. Seasonal changes in soil moisture levels are assessed using probes to measure different depths, measuring slope angle and position and analyzing soil samples. Systematic measurements of soil erosion and deposition for each forest type are also carried out, with immediate re-measurement after major rainstorm events - largely through engineering erosion bridges and measuring the rates at which they erode.
Applying the research to the real world
Results from the biodiversity research will contribute to research-led forest restoration schemes in Borneo, where priority is given not only to productivity (i.e. timber yield), but also to maintaining biodiversity and ecosystem functioning.
The research into soil erosion helps to quantify its impact on the river system after heavy rainfall events - both in the river adjacent to these areas of forest and further downstream. This knowledge enables management strategies to be developed to prevent or lessen the ecosystem damage and economic losses caused. The scientists will deliver this information to the Drainage and Irrigation Department which manages the waterways in the district of Sabah. Their findings are of national relevance to both the state and federal governments, where concern is increasing about the implications of an increasingly flood-prone climate on the sustainability of socioeconomic development - because of the threats that floods pose to floodplain agriculture, bridges, coastal tourism and water supply.
Find out more about Climate Change and Landscape in Borneo's Rainforest.