Increasing Demand for Natural Rubber Necessitates a Robust Sustainability Initiative to Mitigate Impacts on Tropical Biodiversity

Abstract

Strong international demand for natural rubber is driving expansion of industrial-scale and smallholder monoculture plantations, with >2 million ha established during the last decade. Mainland Southeast Asia and Southwest China represent the epicenter of rapid rubber expansion; here we review impacts on forest ecosystems and biodiversity. We estimate that 4.3-8.5 million ha of additional rubber plantations are required to meet projected demand by 2024, threatening significant areas of Asian forest, including many protected areas. Uncertainties concern the potential for yield intensification of existing cultivation to mitigate demand for new rubber area, versus potential displacement of rubber by more profitable oil palm. Our review of available studies indicates that conversion of forests or swidden agriculture to monoculture rubber negatively impacts bird, bat and invertebrate biodiversity. However, rubber agroforests in some areas of Southeast Asia support a subset of forest biodiversity in landscapes that retain little natural forest. Work is urgently needed to: improve understanding of whether land-sparing or land-sharing rubber cultivation will best serve biodiversity conservation, investigate the potential to accommodate biodiversity within existing rubber-dominated landscapes while maintaining yields, and ensure rigorous biodiversity and social standards via the development of a sustainability initiative.

Producing Diversity: Agroforests Sustain Avian Richness and Abundance in India's Western Ghats

“…These results have direct consequences for current land-sharing management practices including land conversions (change in crop type), pesticide use, maintaining understory and native tree cover. Given the sensitivity of coffee, rubber and areca cropping strategies, particularly with shifting farm gate prices, current subsidy packages, costs of inputs and labor, as well as larger cultural and political conditions (Hausermann, 2014;Robbins et al, 2015;Warren-Thomas et al, 2015), the conservation of biodiversity in the Ghats requires linking of land-sharing and land-sparing approaches (Das et al, 2006;Karp et al, 2012;Haggar et al, 2013). Policy shifts and role of global-local markets for these commodities will need to further "value" these landscapes to ensure effective biodiversity conservation outcomes.…”

“…Covering 38% of the planet's landmass, production landscapes such as tea, coffee, rubber, cacao, arecanut, and rice are known to support a diversity of birds, mammals, amphibians and other ecologically sensitive species in the tropics (Bhagwat et al, 2005;Faria et al, 2006;Perfecto and Vandermeer, 2008;Gardner et al, 2009;Anand et al, 2010;Foley et al, 2011;Robbins et al, 2015;Warren-Thomas et al, 2015). These human-cultivated landscapes support particular species or taxonomic groups, making it essential to understand which species persist and why they persist in such habitats (Daily et al, 2001;Bhagwat et al, 2008;de Lima et al, 2013;Maas et al, 2013;Mendenhall et al, 2014;Pryde et al, 2016).…”

Conversion of lowland tropical forests to tree cash crop plantations loses up to one-half of stored soil organic carbon

“…Oil palm production areas have grown by nearly 260% (to 15.9 Mha), cacao by 166% (to 9.5 Mha), and rubber by 143% (to 9.4 Mha) (1). It is also recognized that much of the expansion of these tree cash crop plantations comes at the expense of lowland tropical forests (2,3). Although extensive emphasis is given to the impacts of oil palm plantations in tropical carbon-rich peatlands (4,5), mineral soils, which have a far larger areal coverage across the tropics (6), are receiving comparatively less attention for this land use.…”

Assessment of governance mechanisms, livelihood outcomes and incentive instruments for green rubber in Myanmar

“…In mountainous areas of Southeast Asia, rubber has been shown to induce drier conditions at the local level, surface erosion, loss of soil health, sedimentation and disruption of stream flows, and increase the risk of landslides (Ziegler et al 2009). Additionally, carbon emissions are likely to increase when primary or secondary forests are converted to rubber (Fox et al 2014;Warren-Thomas et al 2015).…”