Ecological and socio-economic functions across tropical land use systems after rainforest conversion

Abstract

Tropical lowland rainforests are increasingly threatened by the expansion of agriculture and the extraction of natural resources. In Jambi Province, Indonesia, the interdisciplinary EFForTS project focuses on the ecological and socio-economic dimensions of rainforest conversion to jungle rubber agroforests and monoculture plantations of rubber and oil palm. Our data confirm that rainforest transformation and land use intensification lead to substantial losses in biodiversity and related ecosystem functions, such as decreased above- and below-ground carbon stocks. Owing to rapid step-wise transformation from forests to agroforests to monoculture plantations and renewal of each plantation type every few decades, the converted land use systems are continuously dynamic, thus hampering the adaptation of animal and plant communities. On the other hand, agricultural rainforest transformation systems provide increased income and access to education, especially for migrant smallholders. Jungle rubber and rubber monocultures are associated with higher financial land productivity but lower financial labour productivity compared to oil palm, which influences crop choice: smallholders that are labour-scarce would prefer oil palm while land-scarce smallholders would prefer rubber. Collecting long-term data in an interdisciplinary context enables us to provide decision-makers and stakeholders with scientific insights to facilitate the reconciliation between economic interests and ecological sustainability in tropical agricultural landscapes.

Biodiversity and ecosystem functioning in dynamic landscapes

“…Different effects of grassland management on plant species richness and productivity resulted in a wide-range ecosystem-specific BEF relationships that were either positive, neutral or negative [61]. Similarly, another article of this special issue studies the effects of land use changes and anthropogenic impacts on BEF relationships in a tropical landscape [62]. Rainforest transformation and land use intensification reduced both biodiversity and related ecosystem functions, such that economic interests and ecological properties need to be addressed jointly to inform stakeholders and decision-makers about the trade-off between crop choices and the stability of biodiversity and ecosystem functions [62].…”

“…Similarly, another article of this special issue studies the effects of land use changes and anthropogenic impacts on BEF relationships in a tropical landscape [62]. Rainforest transformation and land use intensification reduced both biodiversity and related ecosystem functions, such that economic interests and ecological properties need to be addressed jointly to inform stakeholders and decision-makers about the trade-off between crop choices and the stability of biodiversity and ecosystem functions [62]. Together, these studies highlight that anthropogenic management of ecosystems can have a tremendous effect on biodiversity-ecosystem functioning relationships strongly contrasting with those frequently observed in controlled experimental studies.…”

Expansion of oil palm and other cash crops causes an increase of the land surface temperature in the Jambi province in Indonesia

“…Indonesia is one of the regions where the expansion of cash crop monocultures such as acacia (timber plantations), rubber, oil palm plantations and smallholder agriculture has drastically reduced the area of primary forest in the last 2.5 decades (Bridhikitti and Overcamp, 2012;Drescher et al, 2016;Marlier et al, 2015;Miettinen et al, 2012;Verstraeten et al, 2005). This large-scale conversion of rainforest for agricultural use has been observed on the island of Sumatra, which has experienced the highest primary rainforest cover loss in all of Indonesia (Drescher et al, 2016;Margono et al, 2012;Miettinen et al, 2011).…”

“…This large-scale conversion of rainforest for agricultural use has been observed on the island of Sumatra, which has experienced the highest primary rainforest cover loss in all of Indonesia (Drescher et al, 2016;Margono et al, 2012;Miettinen et al, 2011). Forest cover in the Sumatran provinces of Riau, North Sumatra and Jambi declined from 93 to 38 % of provincial area between 197738 % of provincial area between and 200938 % of provincial area between (Mietti-nen et al, 2012.…”

“…Forest cover in the Sumatran provinces of Riau, North Sumatra and Jambi declined from 93 to 38 % of provincial area between 197738 % of provincial area between and 200938 % of provincial area between (Mietti-nen et al, 2012. These large-scale transformations, observed as land cover change, and land use intensification have led to substantial losses in animal and plant diversity, ecosystem functions and changed microclimatic conditions Dislich et al, 2016;Drescher et al, 2016). Additionally, these changes directly alter vegetation cover and structure and land surface properties such as albedo, emissivity and surface roughness, which affect gas and energy exchange processes between the land surface and the atmosphere (Bright et al, 2015).…”