Riparian buffers in tropical agriculture: Scientific support, effectiveness and directions for policy

Abstract

1. There is a weak evidence base supporting the effective management of riparian ecosystems within tropical agriculture. Policies to protect riparian buffers-strips of non-cultivated land alongside waterways-are vague and vary greatly between countries.2. From a rapid evidence appraisal, we find that riparian buffers are beneficial to hydrology, water quality, biodiversity and some ecosystem functions in tropical landscapes. However, effects on connectivity, carbon storage and emissions reduction remain understudied. Riparian functions are mediated by buffer width and habitat quality, but explicit threshold recommendations are rare. Policy implications.A one-size fits all width criterion, commonly applied, will be insufficient to provide all riparian functions in all circumstances. Context-specific guidelines for allocating, restoring and managing riparian buffers are necessary to minimise continued degradation of biodiversity and ecosystem functioning in tropical agriculture.

Morphological traits mediate fish occurrences in oil palm‐impacted tropical streams

“…Our findings suggest that impacts to stream fish assemblages may be ultimately driven by the degradation of riparian vegetation, which underscores the need for continued emphasis on maintaining riparian buffers along streams, as well as the restoration of degraded riparian habitats. Riparian buffers have been shown to be effective in mitigating land‐use impacts on fishes as well as many terrestrial taxa (Lorion & Kennedy, 2009; Luke et al, 2019), which could in turn aid in the preservation of ecosystem functions by mitigating shifts in trait values associated with forest conversion.…”

Riparian reserves help protect forest bird communities in oil palm dominated landscapes

“…Despite a growing number of ecological studies on tropical riparian reserves, there is still little information regarding which features have the greatest benefit for biodiversity (Luke et al., In preparation). For birds in oil palm, we find that riparian reserve width is an important predictor of overall number of species, with reserves at least 40 m wide (i.e., 80 m total width) supporting comparable numbers of species to riparian forest controls.…”

Effects of Replanting and Retention of Mature Oil Palm Riparian Buffers on Ecosystem Functioning in Oil Palm Plantations

“…Current riparian buffer policy in tropical ecosystems has a limited ecological basis due to a lack of available information (see Luke et al, 2019 for a review). The results of this study suggest that mature oil palm riparian buffers do not appear to have negative impacts on the surrounding plantation.…”

“…Riparian buffers are a legal requirement in many Southeast Asian countries, and are a requirement of Roundtable on Sustainable Palm Oil (RSPO) and Indonesian Sustainable Palm Oil (ISPO) certified plantations (Barclay et al, 2017; Roundtable on Sustainable Palm Oil (RSPO), 2018). There are beneficial hydrological impacts of riparian buffers (Tabacchi et al, 2000;Mayer et al, 2007) and forested riparian reserves have also been shown to be effective for conserving biodiversity associated with tropical forests (Gray et al, , 2015de la Peña-Cuéllar et al, 2015;Luke et al, 2019).…”