BCAS Vol.30 No.1 2016 Environment Interplanting Facilitates Water Utilization of Rubber Trees in Xishuangbanna

a n y n a t u r a l f o r e s t s have examined water use in such the beneficial effects of have been converted systems. macrophylla on rubber plantation Mto monoculture rubber Prof. LIU Wenjie and his team with respect to water use. (Hevea brasiliensis) plantations form Xishuangbanna Tropical The researchers measured the in Xishuangbanna, which brought Botanical Garden conducted a stable isotope ratios (δD and δ18O) negative impacts on biodiversity of study to test whether interplanting of water in , rain, and the region. The rubber agroforestry with Flemingia macrophylla, a tissue samples to quantitatively system, which combines agricultural leguminous, perennial, leafy , distinguish plant water sources. They and forestry technologies to create could facilitate the water utilization also measured leaf δ13C and the soil a more diverse, productive, healthy, of rubber trees. They investigated water content over the course of a and sustainable land-use system, the interspecific and intraspecific rainy/dry season cycle (2013–2014) is regarded as the best way to differences and variation in Hevea- to compare the interspecific and improve the sustainability of rubber Flemingia agroforestry systems intraspecific water use efficiency and monocultures. However, few reports among seasons in order to realize moisture conservation ability of the

Monoculture rubber plantation (left) and Hevea-Flemingia agroforestry system (right) in Xishuangbanna.

42 Bulletin of the Chinese Academy of Sciences Vol.30 No.1 2016 Science Watch Environment system, respectively. To characterize greatly conserved soil water and Flemingia macrophylla could the ecophysiological properties of helped maintain local microclimatic extract water from different source. the plants, they measured the leaf stability, despite in face of the The results suggested that planted C and N concentrations and shoot adverse factors. To avoid intense with Flemingia macrophylla had water potential. competition with the interplanted more beneficial effects than single The study found that the Hevea- species for water, rubber trees cropping. Flemingia agroforestry systems expanded their water absorption zone The study entitled “Below- maintained much more soil water to the deep soil layer. Interplanting ground Interspecific Competition than rubber monoculture systems. could improve the water use for Water in a Rubber Agroforestry The agroforestry systems reduced efficiency and productivity of rubber System May Enhance Water soil moisture evaporation via tree via species interaction. The Utilization in Plants” has been undergrowth coverage and can thus rubber plants and the interplanted published in Scientific Reports.

Relative water use for various sources for rubber trees and interplanted species at both sites during the investigation.

Bulletin of the Chinese Academy of Sciences 43