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

Zhen Ling,Zhengtao Shi,Guojian Feng,Weiwei Zhu,Shixiang Gu,Tao Wang

doi:10.3389/fpls.2022.830519

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.

Highlights

The remote sensing data on February 22, 1990, February 25, 2000, February 22, 2010, and February 27, 2017 were selected to extract the information of rubber plantation in Xishuangbanna to obtain its spatial distribution in the corresponding years
Assessment of ET0 Change in Rubber Plantation Expansion To quantify the contribution of climate change and rubber plantation expansion to ET0, the following analyses were conducted in the study and control areas: (1) We propose a hypothesis that the area of rubber plantations in the study area did not change during this period, and any change in ET0 in the area is caused by climate change, as ET0 = EToclimate and ET0rubber = 0; (2)We assume that the area under rubber plantations in the study area did not change during this period, and any change in ET0 in the area is caused by climate change
The rubber plantation area was 121,164 ha in 1990, increased to 211,357 ha in 2000, 404,552 ha in 2010, and reached 465,904 ha in 2017, which accounts for 6.38%, 11.12%, 21.29%, and 24.52% of the land area in Xishuangbanna, respectively

Summary

Introduction

Evapotranspiration (ET) is one of the most important elements in the water cycle of ecosystem and a key factor in the regional water balance. Reference evapotranspiration (ET0) is considered as a crucial factor in hydrological and climate research. The detail of ET0 has an important practical significance for analyzing the influence of climate and rubber plantation expansion on regional water resources planning, agricultural planting structure adjustment, and ecological environment protection (Jiao et al, 2020; Xiang et al, 2020; Yang et al, 2021). Climate and land use and cover change (LUCC) have a strong influence on ET0 (Odongo et al, 2019; Zhang et al, 2019; Hu et al, 2021). Few studies attempted to assess the impact of climate change and commercial agricultural activities such as deforestation. Deforestation is considered as an important anthropogenic process affecting climate and hydrology

Methods

Results

Discussion

Conclusion