Land-use Decisions in Complex Commons: Engaging Multiple Stakeholders through Foresight and Scenario Building in Indonesia.

In the midst of global change uncertainties, Indonesian spatial planning authorities are developing 20-year strategies. However, the lack of collaborative engagement of stakeholders and unclear methodology around using futures studies in addressing land management undermine such plans and affect environmental governance. A crucial question is how to link a future-oriented process with governance transformation processes, particularly related to land-use planning and management. To address this issue, we used a co-elaborative scenario-building approach, referred to as participatory prospective analysis (PPA), to facilitate the creation of local multistakeholder platforms considering future-oriented perspectives. The PPA design combines equally the knowledge of local communities, technical experts and decision-makers, and was applied in a series of sequential multistakeholder workshops in two regencies in Indonesia, followed by public consultations on the main results. In both regencies, participants agreed on a common topic related to spatial planning in their jurisdiction to be explored with a 20-year time horizon. They reached consensus on relevant variables, analyzed their dependence/influence, and developed several plausible yet contrasting scenarios for land management and road maps with guidelines for the implementation of desired outcomes. The PPA approach stimulated stakeholder engagement and ensured that more local voices were not only heard but also duly included in the process. It allowed participants to consider strategies that would otherwise have been less readily accepted by their respective organizations. It showed that it is possible to improve existing spatial planning processes in Indonesia by integrating tools for a more inclusive and long-term future-oriented collaborative approach.

Ecosystem Services and Biodiversity in a Rapidly Transforming Landscape in Northern Borneo.

Because industrial agriculture keeps expanding in Southeast Asia at the expense of natural forests and traditional swidden systems, comparing biodiversity and ecosystem services in the traditional forest-swidden agriculture system vs. monocultures is needed to guide decision making on land-use planning. Focusing on tree diversity, soil erosion control, and climate change mitigation through carbon storage, we surveyed vegetation and monitored soil loss in various land-use areas in a northern Bornean agricultural landscape shaped by swidden agriculture, rubber tapping, and logging, where various levels and types of disturbance have created a fine mosaic of vegetation from food crop fields to natural forest. Tree species diversity and ecosystem service production were highest in natural forests. Logged-over forests produced services similar to those of natural forests. Land uses related to the swidden agriculture system largely outperformed oil palm or rubber monocultures in terms of tree species diversity and service production. Natural and logged-over forests should be maintained or managed as integral parts of the swidden system, and landscape multifunctionality should be sustained. Because natural forests host a unique diversity of trees and produce high levels of ecosystem services, targeting carbon stock protection, e.g. through financial mechanisms such as Reducing Emissions from Deforestation and Forest Degradation (REDD+), will synergistically provide benefits for biodiversity and a wide range of other services. However, the way such mechanisms could benefit communities must be carefully evaluated to counter the high opportunity cost of conversion to monocultures that might generate greater income, but would be detrimental to the production of multiple ecosystem services.

Soils on exposed Sunda shelf shaped biogeographic patterns in the equatorial forests of Southeast Asia.

The marked biogeographic difference between western (Malay Peninsula and Sumatra) and eastern (Borneo) Sundaland is surprising given the long time that these areas have formed a single landmass. A dispersal barrier in the form of a dry savanna corridor during glacial maxima has been proposed to explain this disparity. However, the short duration of these dry savanna conditions make it an unlikely sole cause for the biogeographic pattern. An additional explanation might be related to the coarse sandy soils of central Sundaland. To test these two nonexclusive hypotheses, we performed a floristic cluster analysis based on 111 tree inventories from Peninsular Malaysia, Sumatra, and Borneo. We then identified the indicator genera for clusters that crossed the central Sundaland biogeographic boundary and those that did not cross and tested whether drought and coarse-soil tolerance of the indicator genera differed between them. We found 11 terminal floristic clusters, 10 occurring in Borneo, 5 in Sumatra, and 3 in Peninsular Malaysia. Indicator taxa of clusters that occurred across Sundaland had significantly higher coarse-soil tolerance than did those from clusters that occurred east or west of central Sundaland. For drought tolerance, no such pattern was detected. These results strongly suggest that exposed sandy sea-bed soils acted as a dispersal barrier in central Sundaland. However, we could not confirm the presence of a savanna corridor. This finding makes it clear that proposed biogeographic explanations for plant and animal distributions within Sundaland, including possible migration routes for early humans, need to be reevaluated.