Slipping through the Cracks: Rubber Plantation Is Unsuitable Breeding Habitat for Frogs in Xishuangbanna, China

Abstract

Conversion of tropical forests into agriculture may present a serious risk to amphibian diversity if amphibians are not able to use agricultural areas as habitat. Recently, in Xishuangbanna Prefecture, Yunnan Province – a hotspot of frog diversity within China – two-thirds of the native tropical rainforests have been converted into rubber plantation agriculture. We conducted surveys and experiments to quantify habitat use for breeding and non-breeding life history activities of the native frog species in rainforest, rubber plantation and other human impacted sites. Rubber plantation sites had the lowest species richness in our non-breeding habitat surveys and no species used rubber plantation sites as breeding habitat. The absence of breeding was likely not due to intrinsic properties of the rubber plantation pools, as our experiments indicated that rubber plantation pools were suitable for tadpole growth and development. Rather, the absence of breeding in the rubber plantation was likely due to a misalignment of breeding and non-breeding habitat preferences. Analyses of our breeding surveys showed that percent canopy cover over pools was the strongest environmental variable influencing breeding site selection, with species exhibiting preferences for pools under both high and low canopy cover. Although rubber plantation pools had high canopy cover, the only species that bred in high canopy cover sites used the rainforest for both non-breeding and breeding activities, completing their entire life cycle in the rainforest. Conversely, the species that did use the rubber plantation for non-breeding habitat preferred to breed in low canopy sites, also avoiding breeding in the rubber plantation. Rubber plantations are likely an intermediate habitat type that ‘slips through the cracks’ of species habitat preferences and is thus avoided for breeding. In summary, unlike the rainforests they replaced, rubber plantations alone may not be able to support frog populations.

Spatio-temporal variations of conservation hotspots based on ecosystem services in Xishuangbanna, Southwest China

“…Although artificial afforestation could have negative effects on forest biodiversity and natural connectivity compared with natural forests [ 39 ], the main purpose and function of plantation in deforested regions could contribute to land recovery and biodiversity protection to reduce ecological degradations to some extent [ 40 , 41 ]. As for Jinghong County, rubber was the main type of plantation and became the selective habitat of Asian elephant and intermediate habitat of some amphibians [ 42 , 43 ]. Because of the field-data limitation, only habitat quality from1990 and 2010 were validated by animal occurrence records from previous studies [ 44 , 45 ].…”

Comparative responses of termite functional and taxonomic diversity to land‐use change

“…The conversion of natural forests to rubber plantations in general drastically decreases species diversity. Compared with natural forests, rubber plantations decreased the diversity of soil nematodes by 33% (Xiao et al, 2014), the diversity of bird species by c. 34-56% (Sreekar et al, 2015;Zhang et al, 2017), anuran diversity by 38.9% (Behm et al, 2013), spider diversity by 50-57.4% (Zheng et al, 2015), and leaf litter ant diversity by 28% (Liu et al, 2016). These dramatic changes stimulated our interest in the impact of such forest conversion on termite diversity and communities in tropical regions.…”

Signals of forest degradation in the demography of common Asian amphibians

“…In peninsular Malaysia, M. heymonsi is more strongly associated with oil palm plantations, or open habitats, than mature secondary forests ( Faruk et al, 2013 ). In southern China, M. fissipes is more abundant at disturbed sites than in intact rainforest ( Behm, Yang & Chen, 2013 ). Many frogs in this genus are considered habitat generalists and prior to major degradation of forests in the region, these species probably bred only in forest gaps—open areas in forests caused by windfall of trees and subsequent pooling of water.…”