Key findings of EFForTS (2012 - 2019)

Over the last decades, the lowlands of Jambi province in Sumatra (Indonesia) have undergone a major transformation from forests towards a crop-dominated landscape of rubber and oil palm plantations. EFForTS is a Collaborative Research Centre 990 funded by the German Research Foundation (DFG) that investigates the ecological and socio-economic effects of such transformation based on research carried out in the Bukit Duabelas and Hutan Harapan area in Jambi province focusing on smallholder systems (Drescher et al. 2015). In the EFForTS project, more than 160 researchers from the University of Göttingen in Germany and the Indonesian universities IPB (Bogor Agricultural University), UNTAD (Tadulako University) and UNJA (Jambi University) work in close cooperation, representing a wide range of disciplines including ecology, forestry, agriculture, remote sensing, economics, human geography, and cultural anthropology.

The first six years of research of the CRC 990 revealed complex trade-offs between ecological and socio-economic effects. Here we summarize the key findings.

Environmental effects: Land transformation from forest to crops such as oil palm or rubber resulted in large effects on environmental processes including a decrease in carbon stocks, changes in water-use (depending on management intensity) and heating of the land surface. Our findings are detailed here.
Biodiversity effects: Land transformation from rainforest to plantations resulted in severely reduced local diversity and strong shifts in plant and animal community composition. Moreover, important ecological functions were impaired or relied on a few species only, suggesting that ecosystem functions and services in plantations are sensitive to environmental changes. Our findings are detailed here.
Socio-economic effects: The cultivation of rubber and oil palm led to broad-based economic and social benefits such as increased income for farm and non-farm households as well as reducing poverty rates. However, at times the land transformation also caused tension over land, and conflicts among contrasting interest groups. Our findings are detailed here.
Biodiversity enrichment with tree planting in oil palm plantations: Planting islands of native trees in oil palm plantations had positive ecological as well as economic impacts during the first years after planting. While biodiversity and ecosystem functions are expected to further increase with time, oil palm yields may eventually be negatively affected with increasing tree growth. Our findings are detailed here.

Conclusion
The transformation of the lowland forests of Jambi province towards a crop-dominated landscape had pronounced effects on ecological and socio-economic functions (Figure). While the environmental effects were predominantly negative, the cultivation of rubber and especially oil palm contributed to higher income, poverty reduction, and improved living standards among smallholder farmers and rural workers although at times this contributed to increased conflict over land ownership. These trade-offs between the ecological and socio-economic effects need to be accounted for in sound policies for more sustainable land use. Management measures, such as enriching monoculture plantations with other tree species, are able to mitigate some of the negative effects and deserve further study.

Figure 2 Key Fundings
Figure. Land-uses and associated ecological functions. Forest remnants (a,e), jungle rubber (b,f), rubber plantation (c,g) and oil palm plantation (d,h). Ecological functions are represented as flower diagrams. The size of the flower petals indicates the relative strength of an ecosystem function in a given land use. Figure from Clough et al. (2016)