Trees and Regeneration in Rubber Agroforests and Other Forest-Derived Vegetation in Jambi (Sumatra, Indonesia)

Abstract

The rubber agroforests (RAF) of Indonesia provide a dynamic interface between natural processes of forest regeneration and human's management targeting the harvesting of latex with minimum investment of time and fi nancial resources. The composition and species richness of higher plants across an intensifi cation gradient from forest to monocultures of tree crops have been investigated in six land use types (viz. secondary forest, RAF, rubber monoculture, oil palm plantation, cassava fi eld and Imperata grassland) in Bungo, Jambi Province, Indonesia. We emphasize comparison of four different strata (understory, seedling, sapling and tree) of vegetation between forest and RAF, with specifi c interest in plant dependence on ectomycorrhiza fungi. Species richness and species accumulation curves for seedling and sapling stages were similar between forest and RAF, but in the tree stratum (trees > 10 cm dbh) selective thinning by farmers was evident in a reduction of species diversity and an increase in the proportion of trees with edible parts. Very few trees dependent on ectomycorrhiza fungi were encountered in the RAF. However, the relative distribution of early and late successional species as evident from the wood density distribution showed no difference between RAF and forest.

Social Role-Play Games Vs Individual Perceptions of Conservation and PES Agreements for Maintaining Rubber Agroforests in Jambi (Sumatra), Indonesia

“…Studies show that rubber agroforest is an important agro-ecosystem type that supports biodiversity conservation (Williams et al 2001). Although rubber agroforest serves as a refuge for Red List and threatened species (Griffith 2000, Schroth et al 2004, Rasnovi 2006, Beukema et al 2007, Tata et al 2008, it also provides ecosystem services such as soil conservation, protection of water quality, carbon sequestration, reduction of fire hazard, and landscape beauty (Joshi et al 2003, Suyanto et al 2005.…”

Diversity of Birds Across Land Use and Habitat Gradients in Forests, Rubber Agroforests and Rubber Plantations of North Sumatra

“…Monoculture rubber plantations are managed by companies and farmers with greater resources. The basal area of rubber monocultures is lower than that in the natural forest, because there are no large trees in the plantations (van Noordwijk, Tata, Xu, Dewi, & Minang, 2012;Tata, van Noordwijk, & Werger, 2008).…”

Oil Palm Agroforestry Can Achieve Economic and Environmental Gains as Indicated by Multifunctional Land Equivalent Ratios

“…The deforestation observed and the associated greenhouse gas emissions and biodiversity loss have hence been attributed to "agriculture" as driver, rather than to transformations to fastwood plantations as part of "forest management" (Koh and Wilcove, 2008;Sheil et al, 2009;Koh et al, 2011;Carlson et al, 2012;van Noordwijk et al, 2017a). Yet, expansion of oil palm and the ease of obtaining the required permits have had major effects, replacing a very diverse natural vegetation, or still diverse rubber-based agroforestry (Joshi et al, 2003;Tata et al, 2008;Villamor et al, 2014) with a monoculture of oil palms, leaving only small riparian zones or local hills as "high conservation value areas." The multitude of "ecosystem services" of these diverse landscapes have been replaced by a singular focus on "provisioning" services for external markets (Tscharntke et al, 2012), providing income from which farmers or plantation labourers will have to buy what they in the past could obtain for free.…”