Nazarreta, R., Hartke, T.R., Hidayat, P., Scheu, S., Buchori, D. & Drescher, J.

Rainforest conversion to smallholder plantations of rubber or oil palm leads to species loss and community shifts in canopy ants (Hymenoptera: Formicidae)

Currently, our understanding of the responses of ant communities under rainforest conversion to cash crops in SE Asia is based on comparisons of primary rainforests to large company-owned oil palm estates in Malaysian Borneo and a few comparisons of natural forests to rubber plantations in Thailand and China. In Indonesia, second largest rubber producer and largest oil palm producer worldwide, the vast majority of its rubber economy and almost half its oil palm acreage relies on smallholder farmers. This study compares canopy ant communities among four land-use systems in Jambi Province, Sumatra, Indonesia: 1) lowland rainforest, 2) jungle rubber (i.e., extensive rubber cultivation), and monoculture plantations of 3) rubber or 4) oil palm. Smallholder plantations of rubber and oil palm support less than 25% of the abundance and less than 50% of the canopy ant species richness in lowland rainforest, with intermediate levels in jungle rubber. Canopy ant communities from rainforest and jungle rubber were similar and differed from those in monoculture rubber and oil palm plantations, which each hosted distinct communities. Nestedness and turnover also differed between rainforest and jungle rubber on the one hand and rubber and oil palm on the other. This pattern was in part due to significantly greater proportions of tramp ants in the monoculture plantations: While virtually absent in forest (< 1%), six tramp ant species accounted for 9.8% of the collected ant individuals in jungle rubber, 26.6% in rubber and 41.1% in oil palm plantations (up to 88.1% in one studied plantation). Overall, this study improves our understanding of the effects of rainforest conversion to cash crop plantations of rubber and oil palm on ant communities by incorporating smallholder systems in one of the most important regions for oil palm and rubber production worldwide.

Open access, licensed under CC BY 4.0. © 2020 The Author(s).

Nazarreta, R., Hartke, T.R., Hidayat, P., Scheu, S., Buchori, D. & Drescher, J.

Rainforest conversion to smallholder plantations of rubber or oil palm leads to species loss and community shifts in canopy ants (Hymenoptera: Formicidae)

Currently, our understanding of the responses of ant communities under rainforest conversion to cash crops in SE Asia is based on comparisons of primary rainforests to large company-owned oil palm estates in Malaysian Borneo and a few comparisons of natural forests to rubber plantations in Thailand and China. In Indonesia, second largest rubber producer and largest oil palm producer worldwide, the vast majority of its rubber economy and almost half its oil palm acreage relies on smallholder farmers. This study compares canopy ant communities among four land-use systems in Jambi Province, Sumatra, Indonesia: 1) lowland rainforest, 2) jungle rubber (i.e., extensive rubber cultivation), and monoculture plantations of 3) rubber or 4) oil palm. Smallholder plantations of rubber and oil palm support less than 25% of the abundance and less than 50% of the canopy ant species richness in lowland rainforest, with intermediate levels in jungle rubber. Canopy ant communities from rainforest and jungle rubber were similar and differed from those in monoculture rubber and oil palm plantations, which each hosted distinct communities. Nestedness and turnover also differed between rainforest and jungle rubber on the one hand and rubber and oil palm on the other. This pattern was in part due to significantly greater proportions of tramp ants in the monoculture plantations: While virtually absent in forest (< 1%), six tramp ant species accounted for 9.8% of the collected ant individuals in jungle rubber, 26.6% in rubber and 41.1% in oil palm plantations (up to 88.1% in one studied plantation). Overall, this study improves our understanding of the effects of rainforest conversion to cash crop plantations of rubber and oil palm on ant communities by incorporating smallholder systems in one of the most important regions for oil palm and rubber production worldwide.

Open access, licensed under CC BY 4.0. © 2020 The Author(s).