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In Southeast Asia and Asia, large swathes of rainforest have been converted to rubber plantations, with major consequences for biodiversity and ecosystem services. However, the impact of this land use conversion on rhizosphere soil mycobiome has not yet been addressed. This study aimed to investigate how rhizosphere soil fungal communities and their associated biological activity (soil respiration, soil methane (CH4), and potential soil enzyme production) are impacted by the conversion of rainforest to rubber plantations. Fungal richness and community composition in rhizosphere soils collected from natural rainforests, immature rubber, and mature rubber plantations were analyzed using paired‐end Illumina sequencing. The conversion of natural rainforest to rubber plantations significantly altered fungal community composition of specific functional groups (saprotrophs, pathogens, and mycorrhiza). We observed significant loss of saprotrophic and ectomycorrhizal fungi in natural rainforests, but enrichment of plant pathogenic fungi in immature rubber plantations. The mechanism underlying the effects of forest conversion on changes in fungal communities is related to reductions in soil pH, total nitrogen (N), and ammonium (NH4) in rubber plantations. Conversion to rubber plantation also resulted in decline of soil respiration rates and less potential for cellulase and chitinase productions. The significant negative correlations between fungal richness and soil respiration in mature rubber plantations indicated high competition among fungi and low nutrient availability in this system. We demonstrate the negative consequences of the conversion of rainforest to rubber plantations on soil biological activity and significant changes in fungal community composition that could threaten long‐term ecosystem functions. [ABSTRACT FROM AUTHOR]

Abstract: Rubber seed oil, derived from the seeds of the rubber tree – Hevea brasiliensis, has been shown as a viable option for biodiesel production. However, few studies have investigated the factors influencing rubber seed yield. This study evaluates rubber seed yield through in situ counting of rubber seeds from the dominant rubber tree clones (RRIM600# and GT1#) in Xishuangbanna, China. Comparisons of seed yield across tree age classes and along an elevation gradient were carried out. The rubber seed yield survey was then used as a predictor for potential rubber seed oil production, both locally and regionally, and calculates the potential biodiesel production from the rubber seed oil. The results indicate that rubber seed yield is directly linked with tree age and size, and that elevation does not affect rubber seed yield within this region. Seed yield varied greatly (3-fold) between the two cultivars studied. Furthermore, it was calculated that there is a potential production of 1.94 Mt of rubber seed oil and 1.80 Mt of biodiesel from this oil, within SE Asia (Southeast Asia). [Copyright &y& Elsevier]