UC Berkeley Library
Cross-boundary subsidy cascades from oil palm degrade distant tropical forests
- Author(s): Luskin, Matthew Scott
- Brashares, Justin S
- Ickes, Kalan
- Sun, I-Fang
- Fletcher, Christine
- Wright, S. Joseph
- Potts, Matthew D
- et al.
Published Web Locationhttps://www.nature.com/articles/s41467-017-01920-7
Native species that forage in farmland may increase their local abundances thereby affecting adjacent ecosystems within their landscape. We used two decades of ecological data from a protected primary rainforest in Malaysia to illutrate how subsidies from neighboring oil palm plantations triggered powerful secondary ‘cascading’ effects on natural habitats located >1.3 km away. We found (i) oil palm fruit drove 100-fold increases in crop-raiding native wild boar (Sus scrofa), (ii) wild boar used thousands of understory plants to construct birthing nests in the pristine forest interior, and (iii) nest building caused a 62% decline in forest tree sapling density over the 24-year study period. The long-term, landscape-scale indirect effects from agriculture suggest its full ecological footprint may be larger in extent than is currently recognized. Cross-boundary subsidy cascades may be widespread in both terrestrial and marine ecosystems and present significant conservation challenges.