Tropical forest conversion to rubber plantation affects soil micro- & mesofaunal community & diversity

Abstract

Tropical rainforests play important roles in carbon sequestration and are hot spots for biodiversity. Tropical forests are being replaced by rubber ( Hevea brasiliensis ) plantations, causing widespread concern of a crash in biodiversity. Such changes in aboveground vegetation might have stronger impacts on belowground biodiversity. We studied tropical rainforest fragments and derived rubber plantations at a network of sites in Xishuangbanna, China, hypothesizing a major decrease in diversity with conversion to plantations. We used metabarcoding of the 18S rRNA gene and recovered 2313 OTUs, with a total of 449 OTUs shared between the two land-use types. The most abundant phyla detected were Annelida (66.4% reads) followed by arthropods (15.5% reads) and nematodes (8.9% reads). Of these, only annelids were significantly more abundant in rubber plantation. Taken together, α- and β-diversity were significantly higher in forest than rubber plantation. Soil pH and spatial distance explained a significant portion of the variability in phylogenetic community structure for both land-use types. Community assembly was primarily influenced by stochastic processes. Overall it appears that forest replacement by rubber plantation results in an overall loss and extensive replacement of soil micro- and mesofaunal biodiversity, which should be regarded as an additional aspect of the impact of forest conversion.

Converting forests into rubber plantations weakened the soil CH4 sink in tropical uplands

“…Other management factors, such as applying herbicide glyphosate to clear the understory vegetation and sulfur powder to control powdery mildew and anthracnose diseases in rubber plantations, may affect the soil faunal diversity but showed no significant changes in soil microbial community composition and function up to 23-yearold rubber plantations (Li et al, 2016;Singh et al, 2019). Because of lacking of controlled experiments, herbicide and sulfur effects on CH 4 uptake and production by soil microorganisms are even more uncertain and could not be separated from main controlling factors in our case.…”

Forest conversion alters the structure and functional processes of tropical forest soil microbial communities

“…Studies conducted in Indonesia (Schneider et al, 2015), Malaysia (Kerfahi, Dong, Go, & Adams, 2016), and South China (Lan, Li, Jatoi, et al, 2017a; Lan, Li, Lesueur, Wu, & Xie, 2018; Lan, Li, Wu, & Xie, 2017b; Lan, Li, Wu, & Xie, 2017c; Lan, Wu, Li, & Chen, 2020) have found significant differences in soil bacterial communities between rubber plantations and tropical rainforest. Meanwhile, forest conversion can also result in a net loss of soil micro‐ and mesofaunal biodiversity (Singh et al, 2019) and decrease soil fertility and microbial biomass (Allen, Corre, Tjoa, & Veldkamp, 2015). Compared to primary forests, agricultural systems tend to have higher bacterial richness but lower fungal richness (Lan, Li, Jatoi, et al, 2017a; Cai, Zhang, Yang, & Wang, 2018,Tripathi et al, 2012, Kerfahi et al, 2016) and fungal biomass (Monkai et al, 2018).…”

Dominant Tree Species Shape Soil Microbial Community via Regulating Assembly Processes in Planted Subtropical Forests

“…Soil microbial communities consist of a vast diversity of taxa that generally interact with each other via competition and/or mutuality to accomplish their functions (e.g., soil biogeochemical and ecosystem processes), which consequently form complex species co-occurrence networks [17,18]. Microbial networks have been previously determined in soils from various ecosystems, including farmland, forest and grassland [19][20][21][22][23]. Most studies also use microbial network analysis to reveal the keystone taxa that play a critical role in modulating the whole network structure and function, as they often show the dominant relationship among taxa [24,25].…”