Impact of Climate Change and Rubber (Hevea brasiliensis) Plantation Expansion on Reference Evapotranspiration in Xishuangbanna, Southwest China

Abstract

The expansion of rubber (Hevea brasiliensis) cultivation plantation over the past few decades has been significantly explosive in Xishuangbanna, southwest China. More and more evidences concerning the expansion of rubber plantations lead to the negative influence to local regional hydrology. It is vital to explore the impact of climate change and rubber (Hevea brasiliensis) plantation expansion on reference evapotranspiration (ET0) for the sustainable and efficient use of regional water resources. In this study, the spatiotemporal variation of ET0 as well as its relationship in rubber plantations area in Xishuangbanna from 1970–2017 were analyzed by using trend, correlation and contribution analysis. The results showed that the rubber plantation was 12,768 ha yr–1 from 1990 to 2017 in Xishuangbanna, and nearly 40.8% of new rubber plantations expanded above 900 m in altitude from 2000 to 2017. Sunshine duration and average relative humidity were the key meteorological factors that affect ET0 in Xishuangbanna, with the sensitivity coefficient of 0.51 and 0.35, respectively. The multiyear relative change of ET0 in Xishuangbanna was 9.18%, and the total contribution of major climate factors was 7.87% during 1970 and 2017. The average relative humidity in the plantation area decreases, which directly leads to the increase of ET0. The amount of ET0 change from 2000 to 2017 affected by climate change increased at 3.13 mm/10a, whereas it was 2.17 mm/10a affected by the expansion of rubber plantations by quantitative separation. ET0 was significantly affected by climate change but intensified by the expansion of rubber plantation.

Technical Report: Wandering elephants

“…Between 1975 and 2017, the area covered by rubber plantations increased by over 12 per cent and covered over 24 per cent of the Xishuangbanna landscape (Figure 3) (Xu and others, 2014;Liu and others, 2017;Ling and others, 2022).…”

“…Between 1992 and 2010, the rubber plantation area in Xishuangbanna increased in size from around 87,000 ha to about 424,000 ha, equivalent to a 12,768 ha per year average growth rate (Xu and others, 2014;Ling and others, 2022). These facts are particularly concerning for elephants and biodiversity in general, as Xishuangbanna covers less than 5 per cent of China's area but contains almost a fifth of its mammals and more than a third of its birds (Ives, 2013).…”

“…Figure 3: Distribution change of rubber plantations in Xishuangbanna (extracted fromLing and others, 2022) …”