Hydrological consequences of natural rubber plantations in Southeast Asia

Abstract

Since the turn of the century, rubber plantations have been expanding their footprint across Southeast Asia in response to an increasing global demand for rubber products. Between 2000 and 2014, the area cultivated with rubber more than doubled. It is not clear how this major change in the agricultural landscape of Southeast Asia, the main area of rubber production in the world, is affecting land‐use patterns and water resources in the region. Here we use maps of rubber plantations and other croplands in conjunction with a hydrological model and remote sensing analyses to assess land‐use patterns and water resources affected by natural rubber plantations. Results show water requirements of rubber trees are comparable to those of forests but by far exceed those of the other predominant crops and shrubland vegetation with the effect of potentially increasing water scarcity when rubber plantations replace these crops. The expansion of rubber plantations accounts for a 38 km3/yr increase in green water consumption, thereby exacerbating the monthly water scarcity, with an additional 2.4 million people and more than 0.6 Mha facing water scarcity in the driest months as a result of the increase in rubber production. Monthly runoff substantially decreases (by up to 25%) in 14% of the basins where rubber was planted. These results highlight the existence of major land use and hydrological impacts of agricultural development in Southeast Asia that affect the local environment and rural communities, calling for a more sustainable management of the limited land and water resources.

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

“…Driven by rising prices, the expansion of rubber plantations led to dramatic changes in land use and cover change and they were expanded to higher altitude mountains resulting in a dramatic reduction and fragmentation of natural forest area. Furthermore, rubber plantation expansions caused changes in regional microclimate such as temperature increase, humidity decrease, rainfall decrease, and drought ( Gong and Ling, 1996 ; Qiu, 2009 ; Lin et al, 2016 ; Ma et al, 2019 ; Chiarelli et al, 2020 ).…”

Competition for water induced by transnational land acquisitions for agriculture

“…Thus, environmental flows are not available for human water consumption. This methodology to assess blue water scarcity has been extensively used and validated in studies aiming at analyzing the influence of agricultural production on water resources 19 , 59 – 61 . Losses associated with low irrigation efficiencies (i.e., with the difference between water withdrawal and consumption) are not accounted for because that water is not evapotranspired but turns into surface and groundwater runoff and is therefore available for downstream uses, except for the case of coastal areas.…”

Sustaining Biomaterials in Bioeconomy: Roles of Education and Learning in Mekong River Basin

“…We have also provided information and materials on system approaches relevant to curriculum development [35] to improve the management of agriculture and resources [36], agroecosystem analysis [37], and developmental evaluation (DE) [38]. [39]; Country boundary redrawn from [40]; MRB boundary from redrawn [41].…”

“…However, education (second-hand knowledge) and learning (first-hand knowledge) of the potentials and opportunities of biomaterial production and utilization in higher education institutions need to be elaborated on, and various priority actions and intermediate goals must be clearly defined [42]. [39]; Country boundary redrawn from [40]; MRB boundary from redrawn [41].…”

“…Rubber plantations in the Lower Mekong Basin (LMB) and Mekong River Basin (MRB) in the inlet map. Source: Rubber plantations redrawn from[39]; Country boundary redrawn from[40]; MRB boundary from redrawn[41].…”