Spatio-TEmporal Dynamics of Forest Response to ENSO Drought (STEED)

Globally, almost half of all remaining tropical forest is allocated for timber production, illustrating the enormous economic asset that these forests represent to many nations. Additionally, these forests provide important societal and ecosystem services, from being sources of food through to climate change mitigation and generating income from carbon offset schemes. Compared to undisturbed forests, much less is known about previously logged and degraded forests that are regenerating. Critically, with increasingly smaller areas of undisturbed forest remaining, the economic and societal importance of disturbed forests has become greater in recent years. However, the resilience of these forests i.e. their capacity to respond to short-term perturbations (e.g. ENSO-induced drought) by resisting damage and recovering quickly, is poorly understood. If we are to manage tropical forests, both in terms of their initial exploitation and subsequent rehabilitation, we need to better understand how these systems respond to periodic drought at local to regional scales. Only then can we develop policies and practice that explicitly take into account the impacts of drought and protect the economic and societal benefits derived from these fragile ecosystems.
To provide the evidence from which policy makers and practitioners can better plan forest management strategies we will examine the impact of the current ENSO drought on logged and degraded forests in Borneo, SE Asia, using a combination of ground-based and satellite remote sensing methods. In the field we will examine the response of trees to drought across a disturbance gradient, making use of a network of forest inventory plots that were established in the mid-1990s at the time of the last major ENSO drought to affect the region. In 2014 these plots were revisited as part of a long-term study into post-logging recovery of disturbed forests and as such represent a unique natural laboratory for comparing ENSO-induced changes in forest structure, composition and ecosystem functioning across a land-use gradient and addressing the interactions of logging disturbance and drought. We will revisit 25 plots at least four times during the 18 month project. At each plot we will measure a variety of leaf traits, canopy structure and tree mortality. This will be done by a joint team of UK and Malaysian research assistants who will harvest leaves and analyse leaf chemical properties in facilities at the Universiti of Malaysia.
Additionally we will collect spectral reflectance measurements from the leaves. This will allow us to scale up our field observations to use multispectral satellite images to map forest response to the current drought across wider regions. In particular, we will make use of the new Sentinel-2 earth observing satellite to generate region-wide maps of current drought impact, whilst also producing a 20 year time-series drought index from NOAA AVHRR imagery. The latter will provide evidence of the temporal response of the forest to drought in comparison with non-drought conditions, whilst the former will allow us to map the spatial coherence of forest response, determining whether prior disturbance or other factors affect the resilience of forests to drought events. Finally, we will track changes in canopy structure and composition through observations from UAV-mounted sensors, from which we will examine the dynamics of liana/tree composition, which appear to change during drought conditions.
With our project partners, the South East Asian Rainforest Research Programme and Permian Global, we will engage with a network of actors who are responsible for forest management across the SE Asia region. We will do this through dissemination activities including a workshop in Malaysia, where will present evidence of the impact of the current ENSO on SE Asian forests and provide a forum for discussion on how best to adapt forest management policy and practice to future ENSO events.

Beneficiaries of this research will benefit anyone who has a role in developing, influencing or instigating plans and policies relating to the sustainable exploitation and management of tropical forests. By providing direct evidence of the impacts of the current strong ENSO event on forest functioning, resilience and ecosystem services, it will also provide important information for those developing policy and practice to mitigate against the societal and economic impacts of future ENSO events. In particular, we anticipate this work being of benefit to:
(i) local inhabitants who rely on the ecosystem services provided by logged and degraded forests across SE Asia, whether that is for employment, timber extraction, fuel, medicine or food production. Better stewardship of forests in ways that specifically take into account the impacts of drought will help preserve and manage these ecosystems to provide societal benefits for the long-term.
(ii) regional and state governments in SE Asia that need to plan for the impacts of ENSO, the management of natural resources and societal impacts that arise from drought effects upon the ecosystem services delivered by logged an degraded forests.
(iii) organisations, such as Permian Global, and other investment firms dedicated to the protection and recovery of natural forests to mitigate climate change, and who provide an important source of income to developing nations.
(iv) International non-governmental conservation organisations and networks, such as the South East Asian Rainforest Research Programme and the Rainforest Trust who have ongoing projects based in SE Asia.
We will ensure that these impacts are delivered by a variety of dissemination activities, including public engagement with UK organisations that help translate biodiversity research into materials in schools, thus raising awareness of ENSO impacts in future generations of UK school-children.
Academic dissemination will be via high impact publications, conferences and a dedicated project workshop. At this event, hosted by the University of Nottingham in Kuala Lumpur, we will invite leading actors who hold influential positions in forestry management, conservation and policy development to both hear about our work and help us to translate the project outcomes into future policies to mitigate the impacts of ENSO and drought more widely. These invited delegates will be drawn from across SE Asia, supported by links to organisations with which we currently collaborate, including the Indonesian Institute for Sciences (LIPI). At this event we will also highlight the advances in remote sensing that make monitoring of these events much easier and more detailed than ever before, running a 'hands-on' workshop to demonstrate these benefits and create a forum for increasing capacity within SE Asia for monitoring environmental change with remote sensing technologies.