No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
The water-land-food nexus of natural rubber production
Abstract
The increasing global demand for natural rubber (100% increase in the last 15 years) is for most part met by Malaysia and Indonesia, and - to a lesser extent - other countries in South-East Asia and Africa. The consequent expansion of rubber plantation has often occurred at the expenses of agricultural land for staple crops, particularly in South-East Asia, where 90% of the land suitable for agriculture is already under cultivation. Here we investigate the extent to which the ongoing increase in rubber production is competing with the food system and affecting the livelihoods of rural communities living in the production areas and their appropriation of natural resources, such as water. We also investigate to what extent the expansion of rubber plantations is taking place through large scale land acquisitions (LSLAs) and evaluate the impacts on rural communities. Our results show how rubber production needs more than 10 million ha of fertile land and up to 136-149 × 10⁹ m³ y⁻¹ of freshwater (125 × 10⁹ m³ y⁻¹ of green water and 11-24 × 10⁹ m³ y⁻¹ of blue water). These resources would be sufficient to produce enough food to significantly reduce malnourishment in Indonesia, Thailand, and Vietnam if replaced by rice production. Overall, natural rubber production has important environmental, social, and economic impacts. Indeed, despite their ability to bring employment and increase the average income of economically disadvantaged areas, rubber plantations may threaten the local water and food security and induce a loss of rural livelihoods - particularly when the new plantations result from LSLAs that displace semi-subsistence forms of production - thereby forcing the local populations to depend on global food markets.
... The impacts of land acquisitions on well-being depend on a range of factors. Prior research has identified important factors to include the type, size, state of the acquisition (Andersson et al., 2016;Chiarelli et al., 2018;Deininger & Byerlee, 2011;Nolte & Ostermeier, 2017), prior land use (Edelman, 2013), implementation of the acquisition (De Schutter, 2011;Titche, 2017), engagement of local communities in decision making (McCarthy, 2010), and socio-ecological contexts Scoones et al., 2013). But understanding remains limited about how these factors combine in different ways, how they impact human well-being, what processes explain different well-being outcomes, and how differences in social-ecological contexts affect differences in outcomes. ...
... Type of commodity Different commodities require different levels of inputs including water, agrochemicals (Borras et al., 2011;Chiarelli et al., 2018;Johansson et al., 2016) and labour (Deininger & Byerlee, 2011;Hallam, 2009). Land acquisitions with inputs of higher environmental impacts or lower labour intensity are expected to lead to worse well-being outcomes ( Kleemann & Thiele, 2015;Nolte & Ostermeier, 2017). ...
Land acquisitions are transforming land-use systems globally, and their characteristics and impacts on human well-being have been extensively analysed through local case studies and regional or global inventories. However, national-level analysis that is crucial for national policy on sustainable agricultural investments and land use is still lacking. This paper conducts an archetype analysis of a unique dataset on land concessions in Lao PDR to provide a national-scale assessment of the impacts of land acquisitions on human well-being in 294 affected villages. The results show that land acquisitions influence human well-being through 18 distinct pathways. These pathways describe how some land acquisitions enhance or maintain well-being, while others elicit adverse impacts or trade-offs between well-being dimensions, particularly food security, income, and livelihood resilience. They further reveal five archetypical processes that mediate the effects of land acquisitions on well-being through: (i) shifting access to land and natural resources; (ii) commercialization of agriculture; (iii) availability of development opportunities; (iv) environmental impacts; and (v) employment opportunities within and outside land acquisitions. These processes affect well-being by shaping livelihood portfolios and dependence on natural resources. The majority of land acquisitions trigger trade-offs or adverse impacts on well-being. The small number of villages where well-being increased despite the presence of land acquisitions were mainly shaped by narrow and rigid preconditions. The archetypical processes and the explanatory factors suggest that it is imperative to protect smallholders’ land-use rights and to avoid large-scale deals, as their adverse impacts outweigh opportunities and are more severe than the impacts of small-scale acquisitions. Employment opportunities may provide additional cash income but should not be exclusively relied upon.
... Natural rubber is a tropical tree with high water requirements that are usually met by rainfall (i.e., GW) (Mekonnen & Hoekstra, 2011;Chiarelli et al., 2017). The monsoonal climate of Southeast Asia typically provides only part of the water needed to meet the annual water requirement of rubber trees. ...
... These estimates, however, were based on crop parameters (e.g., the kc factor) from the FAO, which have been challenged by some scientists, who have shown how they may lead to overestimates of the CWRs (Giambelluca et al., 2016;Chiarelli et al., 2017) highlighted how, rubber's water demand is much higher than that of the main staple crops planted in the region. Indeed, as noted earlier, rubber plants may act as phreatophytes and meet their water needs by directly taking up blue water from local aquifers. ...
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. Water requirements of rubber trees are comparable to those of forests but by far exceed those of the other predominant crops and shrubland vegetation in the region with the effect of potentially increasing water scarcity when rubber plantations replace these crops. The expansion of rubber plantations accounts for a 38 km3/y 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. This article is protected by copyright. All rights reserved.
... On the other hand, the ecological and carbon footprint are found to decrease. Based on study by Danilo et al. (2018) [24], the green and blue water requirements are determined to link the harvested land and water appropriations for rubber production. The results showed approximately 136 to 149 x 10 9 m 3 y -1 of freshwater are needed for rubber production at over 10 million ha of rich land. ...
... On the other hand, the ecological and carbon footprint are found to decrease. Based on study by Danilo et al. (2018) [24], the green and blue water requirements are determined to link the harvested land and water appropriations for rubber production. The results showed approximately 136 to 149 x 10 9 m 3 y -1 of freshwater are needed for rubber production at over 10 million ha of rich land. ...
Water Footprint Assessment (WFA) has emerged as a new interdisciplinary field of study, that specialize in the study of water use, scarcity, and pollution, in respect to production, consumption, and trade of water-intensive products and services. It consists of the analysis of various techniques and practices, policy plans, and governance mechanisms that contributed to the rise of sustainability, efficiency, and equitability of water footprints. This study focuses on WFA specifically for electronic and food manufacturing products. It determined contributions of different players namely the governments, companies, investors and civil society. This study typically reviews water use in relation to demand for electronic products, food and energy used. It appraisals the sustainable water use translated into coherent food, energy, incentives and trade policies. Water-Food-Energy (WFE) nexus from the perspective of electronic and food manufacturing products are also reviewed. In this study, the challenges in estimating water footprints and WFE nexus for electronics and food manufacturing products include the understanding of various levels of demand, geographical, temporal variations, assessment of uncertainties involved, and the assessment of water-footprint related problems and solutions. The outcomes showed that combining several methods of WFA can obtain adequate results for the water footprint accounting. The WFE nexus is preferred to use life-cycle assessment (LCA) method to identify the environmental impacts. The significances of this study are to raise the awareness on water usage in the supply chain process of the electronic and food products then recommend good practices in water usage.
... Third, I found that inter-sectoral water competitionnamely urban-industrial and environmental flows allocation (e.g., Rasul, 2014;Baleta & Winter, 2016;Shah & Zerriffi, 2017;Cetinkaya & Gunacti, 2018) -was associated with water insecurity in 36.4% of publications (14.6% of listed causes). Water extraction and depletion appeared in 32.3% of the publications (12.6% of listed causes), and included increasing irrigation demand associated with water-intensive cultivation systems, such as rubber plantations (Chiarelli et al., 2017), groundwater extraction for transnational agri-businesses (e.g., Hidalgo et al., 2017), and the potential for extensive water-use to contribute to linked socio-hydrological challenges, such as groundwater salinization (Wurl et al., 2018). ...
In the global South, rural and resource-based livelihoods increasingly face water-related risks. The conceptualization and application of the water security concept in relation to rural livelihoods has not been reviewed in this context. To fill this gap, a systematic scoping review of refereed journal articles (2000–2019) was conducted to examine how water security is defined, driven, and addressed for rural livelihoods in the global South. Publications (n = 99) featured diverse methodologies and geographical contexts, and recognized simultaneous drivers of water insecurity and solution strategies for water security. Several shortcomings were evident. First, only 30.3% of publications defined the concept, mostly using frames of ‘adequate’, ‘sufficient’, and ‘acceptable’ water-related risks. Few definitions recognized the role of water security interventions in increasing capabilities and prosperity. Second, technical and managerial responses to proximate drivers of water-related risk – namely climate-related dynamics, water re-allocation, extraction, and mismanagement – outnumbered efforts to identify and transform the underlying social, economic, and political inequities that create and sustain water insecurity. Last, studies focused heavily on agriculture, while labour, transhumance pastoralism, and aquaculture were underrepresented. A research agenda that increases the synergies between the wider water security and rural livelihoods scholarship is advanced to address these shortcomings. HIGHLIGHTS
A systematic scoping review clarifies how water security is framed and addressed for rural livelihoods.;
Water security focused on conditions of adequacy – not on advancing prosperity.;
Diverse rural livelihoods were underrepresented.;
Systemic processes that create and sustain water insecurity received less attention.;
A research agenda to better understand and address water-related risks for rural livelihoods is provided.;
... These EF are the most explored in the context of rubber plantations, and together can provide a comprehensive understanding of the status of this ecosystem compared to a forest ecosystem. Although some studies have assessed the impact of rubber plantations on ecohydrology (Chiarelli et al., 2018), soil structure (Kurmi et al., 2020), and climate (Song et al., 2019), data on these topics are still limited. As such, they are not included in the scope of our review. ...
The growing global need for latex is driving rubber plantation (RP) expansion since the last century, with >2 Mha of cultivation area being established in the last decade. Southeast Asia is the hotspot for rubber cultivation at other land-use costs. Although rubber cultivation has improved the economic status of farmers, it has altered the habitat's ecology and ecosystem functions (EF). However, studies on the impacts of RP on EF are limited, and a clear overview is not available. To bridge this gap, we conducted an inclusive review of the EF of RP, including soil carbon storage, aboveground biomass (AGB) and belowground biomass (BGB), litter production and decomposition, respiration, and biodiversity (plants, animals, soil fauna, and microbes). We compared the EF in RP (monoculture) with those in forests because the conversion of forests to RP is prevalent in the tropics and because most RP studies used forests as reference ecosystems. We found RP generally have lower EF than forests. The impacts of RP on some EF are more severe (e.g., AGB, BGB, and plant diversity), causing decreases of >55%, and the effects are consistently negative irrespective of plantation age. However, including agroforestry or polyculture, integrated pest management, cover cropping, mulching, and composting can improve the EF in RP to some extent. We highlighted research gaps, particularly substantial research gaps concerning the influence of plant diversity treatments (i.e., agroforestry) performed in RP on EF. Additionally, more empirical data on the significance of spatial and temporal levels are required, such as how the impact on EF could vary with climate and RP age, as we showed some examples where EF differs spatially and temporally. More importantly, further research on plantation management to offset EF losses is needed. Finally, we emphasized knowledge gaps and suggested future directions and policies for improving EF in RP.
... Pastor et al. (2019) evaluated the possible impact of climate change on global land use, water consumption and food trade under several water regulation policy scenarios. Chiarelli et al. (2018) investigated the land-water-food nexus of world rubber production and found that rubber plantation expansion was at the expense of agricultural land for staple crops, and has caused increased usage of fertile land and freshwater. The study by Dalin et al., (2014) found that the increasing volume of food trade in China could increase the pressure on areas with limited water and land resources by outsourcing large amounts of virtual water and land. ...
Soybean import accounts for 90% of China's total domestic soybean supply. Such import has a substantial impact on how the country's resources are used as well as on its environment. In this study, we performed a national-scale assessment of the impact of soybean import on domestic cropland conversion, crop production, water use and nitrogen (N) fertilizer application. Results show that soybean production in China decreased by 26% (4.46 million tons) and sown areas were reduced by 25% (2.39 million ha) from the peak of 2004 to 2016. Of the areas taken out of the soybean production, 70% were converted to maize, 20% to rice, 3% to vegetables and 7% to fruits during this period. As a result of the cropland conversion, the production of maize, rice, vegetables and fruits increased by 10.42, 3.34, 2.49 and 3.26 million tons respectively. However, irrigation water use in the areas that were converted to the cultivation of the four types of crops increased by 96.42% (3.05 km³), with much of it coming from northern provinces where water is generally scarce. The application of N fertilizer increased by 256.65 thousand tons (almost 5 times) on the converted areas, partly due to the loss of the N-fixing soybean cultivation. Although a large quantity of virtual water and land were imported through soybean trade, the water use and N application were increased in reality. The analysis of the land-water-food-environment nexus in the context of soybean import provides comprehensive and useful information about the benefits and trade-offs associated with China's international soybean trade.
... El consumo de este producto depende del estilo y calidad de vida de la población (Cuastumal & Villa, 2007). En los últimos 15 años la demanda mundial se duplicó, principalmente por la creciente fabricación de neumáticos (Chiarelli, et al., 2018). Proyecciones futuras demuestran que la demanda seguirá creciendo en respuesta del desarrollo automotriz (Ahrends, et al., 2015). ...
En los últimos 15 años la demanda mundial de caucho y derivados se duplicó, principalmente la fabricación de neumáticos. La producción de esta materia prima está focalizada en países asiáticos representando 92% de las áreas plantadas a nivel mundial, África y Oceanía 8% y Brasil 1%. Los principales usos están enfocados en la industria automotriz, medicina, farmacéutica y textiles. En el área agrícola se masificó el uso de sistemas de información geográfica (SIG); lo cual nos permite organizar datos de la plantación, el software Qgis de uso libre se utiliza en diferentes campos de estudio. En este trabajo se utilizó Qgis para representar los datos de una plantación de caucho (Hevea brasiliensis) clon Fx 3864, para analizar árboles que cumplen los rangos de diámetro a la altura del pecho (DAP) adecuados para el equipamiento de producción. Mediante las imágenes se observan los árboles que están en producción, evidenciándose 405.Abstract In the last 15 years the global demand for rubber and derivatives has doubled, mainly in the manufacture of tires. The production of this raw material is focused on Asian countries representing 92% of the areas planted worldwide, Africa and Oceania 8% and Brazil 1%. The main uses are focused on the automotive, medicine, pharmaceutical and textile industries. In the agricultural area, the use of geographic information systems (GIS) became widespread; which allows us to organize the plantation data, free-use Qgis software is used in different fields of study. In this work, Qgis was used to represent the data of a rubber plantation (Hevea brasiliensis) clone Fx 3864, to analyze trees that meet the diameter ranges at chest height (DBH) suitable for production equipment. Through the images, the trees that are in production are observed, 405 being evidenced.
... Many research studies that can foster the development and use of renewable energy sources have been realized during the last decade ( Aleixandre-Tudó et al., 2019 ). There have been several studies on oil palm plantations vis-à-vis impacts related to GHGs, water footprint and scarcity, and land use and land use change that leads to the the reduction of food production, etc. ( Gheewala et al., 2011 ;;Gheewala et al., 2014b ;Pensupar, 2015 ;Silalertruksa et al., 2017 ;Nilsalab and Gheewala, 2017a ;Chiarelli et al., 2018 ). However, these studies are mainly based on single issues without considering the interlinkage between related aspects which may yield additional insights. ...
Biofuels for use in on-road transportation have been promoted in Thailand over the past decade to reduce dependence on imported fossil resources as well as possibly reducing greenhouse gas emissions. This has led to an increase in production of biodiesel which is produced from palm oil. However, as palm oil is also used for food, it is important to take this into consideration as well. Also, oil palm cultivation is rather water-intensive. Hence, it is necessary to analyze the interlinkage between water, food, and energy to have a holistic understanding and prevent trade-offs when addressing one issue in isolation. The water-energy-food nexus for oil palm cultivation in Thailand has been conducted following two widely used methods, the Water-Food-Energy Nexus (WFEN) and Water-Energy-Food (WEF) nexus assessment method. The results are demonstrated as a single score, which is easier for suggesting a suitable area for oil palm plantation. The assessment indicates the southern region of Thailand is the most suitable for oil palm plantation. The recommendation is consistent with the suggestion of the government, based on land and climate suitability. However, this study considers more comprehensive aspects including various other environmental aspects. Oil palm cultivation mainly relates to the amount of freshwater consumption, leading to the increment of fuel consumption for pumping water. On the other hand, the effectiveness of fresh fruit bunch yield (for food and energy production) should be developed in the future. Besides, the results recommend the central region for the expansion of oil palm cultivation in the future because of the availability of a good irrigation infrastructure.
... Shifting cultivation dates as far back as 10 000BC (Thrupp et al 1997) and remains the predominant agricultural land-use in many tropical regions, including much of Central and South America, Sub-Saharan Africa, and key areas of conservation interest in Asia and Australasia, notably Bangladesh, Laos and Papua New Guinea (Schmidt-Vogt et al 2009, van Vliet et al 2012, Heinimann et al 2017. Estimations predict at least 260 Mha is currently under the shifting cultivation mosaic (Silva et al 2011, Heinimann et al 2017, more than ten-fold greater than the combined area currently used for oil palm and rubber cultivation (Pirker et al 2016, Chiarelli et al 2018. This mosaic landscape is characterised by a cycle, with a cleared area cultivated for a short period of time (<4 years) and larger areas then left fallow to recover secondary growth of various ages for a prolonged period (up to 30 years). ...
Shifting cultivation is a predominant land use across the tropics, feeding hundreds of millions of marginalised people, causing significant deforestation, and encompassing a combined area of land ten-fold greater than that used for oil palm and rubber. A key question is whether carbon-based payment for ecosystem services (PES) schemes can cost-effectively bring novel restoration and carbon-sensitive management practices to shifting agriculture. Using economic models that uniquely consider the substantial area of fallow land needed to support a single cultivated plot, we calculated the break-even carbon prices required for PES to match the opportunity cost of intervention in shifting agriculture. We do so in the North-east Indian biodiversity hotspot, where 35.4% of land is managed under shifting agriculture. We found net revenues of US$829.53–2581.95 per 30 ha when fallow area is included, which are an order of magnitude lower than previous estimates. Abandoning shifting agriculture entirely is highly feasible with break-even prices as low as US$1.33 t−1 CO2, but may conflict with food security. The oldest fallow plots could be fully restored for US$0.89 t−1 CO2 and the expansion of shifting agriculture into primary forest halted for US$0.51 t−1 CO2, whereas abandoning short-fallow systems would cost US$12.60 t−1 CO2. A precautionary reanalysis accounting for extreme economic uncertainty and leakage costs suggests that all interventions, excluding abandoning short-fallow systems, remain economically viable with prices less than US$4.00 t−1 CO2. Even with poorly formed voluntary carbon markets, shifting agriculture represents a critical opportunity for low-cost forest restoration whilst diversifying income streams of marginalised communities across a vast area.
... Almost half of Southeast Asia's-and the world's-natural rubber is now produced in these expanding regions, in Thailand, Cambodia, Vietnam, Laos, Myanmar, and China (FAOSTAT). Here, 4.7 m ha of rubber plantations have replaced traditional shifting cultivation, which is in steep decline (Ahrends et al. 2015;Heinimann et al. 2017), other food crops such as paddy rice (Chiarelli et al. 2018), and large areas of tropical lowland forests (Warren-Thomas et al. 2018). This has brought relative prosperity to many previously poor areas and people (Sturgeon 2010), but has also resulted in large declines in biodiversity (Clough et al. 2016) and in ecosystem services, including the production of clean water, soil protection, carbon sequestration, and the supply of non-timber forest products (Thellmann et al. 2017). ...
The expansion of rubber plantations in northern Southeast Asia over the last 20 years displaced shifting cultivation and tropical forests. In Xishuangbanna, SW China, rubber occupied 22% of the area by 2010, reducing lowland forest to scattered fragments, with severe impacts on plants, animals, and ecosystem services. The rubber price has declined steeply since 2011, but consequences for forest biodiversity have not previously been explored. We use a new approach for vegetation mapping, combining phenological information with object-based classification, to produce land-use maps for 2002, 2010, 2014, and 2018. During 2002–2018, forest cover declined continuously, from 71 to 52% of the land area, while rubber increased from 11 to 24% by 2014, before declining to 21% by 2018. Other farmlands also declined while tea plantations increased. Forest patch number increased 8-fold during 2001–2014, while patch size decreased 10-fold, but these trends were partly reversed after 2014, with the loss of numerous small (< 1 ha) patches. Most larger (> 10 ha) patches in 2018 were forest throughout the study period, but many smaller patches are secondary. Currently, 20% of Xishuangbanna is in protected areas. Unprotected forest is disproportionately on steep slopes at high altitudes, while biodiversity is highest in valleys and at low altitudes, where only smaller patches remain, creating challenges for conservation planning. We recommend that all the largest patches are preserved, plus smaller patches selected for their biota, and that forest restoration is used to restore connectivity and buffer small patches of high conservation value.
Sustainable development and intergenerational responsibility entail the prudent use of natural resources. Water availability can constrain agriculture, a key sector in terms of resources consumed and goods and services provided. The sustainability of its intensification and expansion has been studied, often with a particular focus on water. Agricultural strategies have been based on local water availability, and some downstream effects have been evaluated. However, a method to identify and quantify hydrologically sustainable land use and crop use changes directly accounting for downstream effects is yet to be defined. We propose a framework to design land‐use and crop‐use changes preventing local and downstream effects. We apply it on of coffee plantations expansion in Kenya, a sector that is growing and planned to grow, given its agricultural, economic and social development potential, not without risks associated to hydroclimatic change. We use crop‐ and land‐use specific hydrological modeling to simulate water scarcity impacts of coffee plantation expansion onto available suitable areas, and use the results to iteratively identify and filter out expansion areas increasing water scarcity locally or downstream. This assessment proves effective in preserving water availability, identifying 10% of the suitable and available areas as hydrologically sustainable. Total water footprints are similar in these expansion areas and in currently used areas, but expansion areas have higher precipitation‐generated water availability. The proposed methodology locates and quantifies areas in a physically robust way, maintaining flexibility to the selected expansion scenario. Thus, the methodology is replicable for planning hydrologically agricultural development.
This article is protected by copyright. All rights reserved.
Rubber (Hevea brasiliensis) plantations have high water consumption through evapotranspiration, which can contribute to water scarcity. In addition, there is a lack of spatial observation data and estimation methods for evapotranspiration (ET) for rubber plantations. To alleviate the water stress of expanding rubber plantations caused by seasonal drought in Xishuangbanna, Southwest China, an up to 7 days crop evapotranspiration (ETc) forecast method, “Kc-ET0” for rubber plantations with limited meteorological data, was proposed by using rubber crop coefficient Kc and public weather forecasts. The results showed that the average absolute error (MAE) of forecasted ETc was 0.68 mm d−1, the root mean square error (RMSE) was 0.85 mm d−1, and the average correlation coefficient (R) was 0.69 during the rainy season, while during the dry season these metrics were 0.52 mm d−1, 0.68 mm d−1, and 0.85, respectively. The accuracy of ETc forecast in the dry season was higher. Additionally, Kc was the main factor influencing the accuracy of rubber plantations ETc forecast, while the accuracy of the temperature forecast and the chosen Hargreaves-Samani (HS) model were also considerable. Our results suggested that the “Kc-ET0” short-term rubber plantation ETc forecasting method shows good performance and acceptable accuracy, especially in the dry season. The study provides an important basis for creating ET-based irrigation scheduling for improving regional-scale water management in high water consumption rubber plantations.
Exploring the interaction between water, land, and food (WLF) is a premise guaranteeing to ease resource restrictions and achieve sustainable development in major agricultural production areas. We chose 26 indicators to build a WLF nexus evaluation index system. We used the coupling coordination model to measure the coupling coordination degree of the WLF nexus in 15 prefecture-level cities and 151 counties under the jurisdiction of Hebei Province in 2000, 2005, 2010, 2015, and 2020. Then, the spatial correlation was analyzed using the global and local Moran’s I. Finally, the regional differences and spatiotemporal patterns were analyzed using a spatial gravity center model and kernel density estimation. The results are as follows: (1) In 11 cities, the comprehensive evaluation index of the WLF and of each subsystem shows a fluctuating upward trend. More than 95% of the counties’ comprehensive evaluation indices improved, and the difference between counties in the north and south narrowed after 2010. (2) The spatial pattern of the WLF in counties has evolved from a pattern of “high in the south and low in the north” to “high in the north and low in the south”, with the development speed of the north being higher than that of the south. (3) The coupling coordination degree of the WLF has a positive spatial autocorrelation relationship in different counties; however, the spatial connection eventually deteriorates, and the geographic pattern exhibits “agglomeration decrease” characteristics. In Hebei Province, the WLF coupling coordination rate slowly improves, and there is a significant development gap between counties. Therefore, local conditions should be taken into consideration when implementing measures to reduce the conflict between water, land, and food in actual regional conditions.
The observed and predicted changes in climate, as well as the growth in urban population, are creating severe stress on existing water resources in South Korea. By the importation of agricultural products from more water-rich countries through the virtual water concept, a country could save local water resources for other important uses. However, these imports from other countries could lead to certain vulnerabilities in the importing country derived from climate change. Therefore, through the application of the virtual water concept and the climate vulnerability index ((CVI) - measure of a country's vulnerability to indirect climate impacts), this study assessed the implication of virtual water imports and climate change through food trade, on the water, land and food security status of South Korea over the period of 2000-2017. The results showed that significant amounts of national water and land was saved through the importation of major upland crops. Virtual water imports increased significantly over time, rising from 16.2 Bm3 in 2000 to 16.5, 17.4, and 20.7 Bm3 in 2005, 2011, and 2017 respectively, with the USA, China, Australia, Brazil and Canada being the major exporters to South Korea. The study also revealed high CVI values for the oils and grains category of imported food, implying the high vulnerability of South Korea to climate change effects resulting from the import of these crops. The quantitative impacts and structural changes in virtual water trade, as well as the link between climate change, food security, international trade, and domestic water consumption could be evaluated for the sustainable management and allocation of resources. This study successfully identified and quantified the status of food trade and its environmental implications in the study area, providing insight into a better allocation of locally available resources.
Challenges at the intersection of water conservation, land protection, food security, and economic growth cross industrial boundaries, and also involve synergies with multiple policy domains. Despite this, little is known about how system heterogeneity affects water, land, and food (WLF) consumption performance at a sectoral level. This study integrates superedge analysis with a flow interaction network, elasticity theory, and utility analysis to detect the WLF nexus with regard to resource efficiency gains. Three indicators (intra-sector recycling efficiency, trans-sector allocation efficiency, and symbiosis of system structure) are proposed as mechanisms by which to quantitatively explore intra-sector and trans-sector nexus, and formulate improvement strategies for sectoral WLF savings. The results show synergies between recycling efficiency and water/food productivity. Manufacturing servitization and agricultural industrialization can drive more efficient WLF allocation by minimizing resource misallocation, whilst positive industrial ecology enhances WLF circulation and facilitates reducing resource undue competition. In addition, the ability of industries to save resources under the nexus is examined. Approximately 93% of sectors suffer from resource waste, misallocation, and undue competition. Therefore, strategic paths enhance resource synergy and, through so doing, enable WLF efficiency gains.
Non‐grain cropland is a typical phenomenon with common characteristics globally. As the most populous country, China's non‐grain cropland threatens global food supply stability and affects food production sustainability under the current complex situation of international food security. This paper used Sichuan Province, China, to explore the formation mechanism of non‐grain and its potential impact on sustainable productivity, given the regional environment complexity and socio‐economic representativeness. High‐precision land survey data were used to detect multi‐scale non‐grain influencing factors and discuss non‐grain impacts on soil state to fill the knowledge gap on micro‐level development of non‐grain phenomena. Results show that rotation‐type is the region's most abundant and widely distributed cropland type, accounting for about 59.38% of the total cropland area; the second is abandonment‐type. Urbanization indicators are the common factors affecting the non‐grain spatial distribution on the global scale; environmental variables' impact on non‐grain shows significant differences in geographical locations on the local scale. Overall, cash‐type and intercrop‐type aim at improving production conditions. Rotation‐type and fallow‐type mostly occur in areas with low production capacity and are prominently driven by policies. Abandonment‐type is subject to terrain constraints, production conditions, and social economy. Additionally, non‐grain trends have not caused significant damage to soil sustainable productivity except for the positive promotion of field biodiversity. Non‐grain cropland can be divided into 3 clusters according to the corresponding average soil fertility state, [rotation], [intercrop, cash, abandonment], and [fallow]. Policymakers must implement specific policies for different cropland types and formulate more refined farming management plans. This article is protected by copyright. All rights reserved.
In this paper, the method of filling natural rubber with zeolite as filler was mainly studied in the following two aspects: firstly, experiments selected organic amine surface modifier to modify natural zeolite and used infrared spectroscopy to analyze the interaction between the modifier and zeolite, and secondly, studying the application of modified zeolite in natural rubber and using scanning electron microscopy to analyze the mechanism of action between zeolite and natural rubber. The test results show that octadecylamine in the modifier had the relatively best effect. Under the best conditions, the activation index of the modified product could reach 95% and above, and the contact angle could reach about 100°. When the filling amount was 30 phr, the octadecylamine modification had the most obvious effect on the performance of zeolite/natural rubber and the composite rubber had better mechanical properties. The corresponding tensile strength, tear strength, elongation at break and Shore hardness were 22.59 MPa, 28.52 MPa, 782.1% and 41, respectively, which were 45.74%, 19.28%, 7.95% and 7.89% higher than those of unmodified zeolite/natural rubber. As the first study of organic amine modified zeolite as a filler for filling natural rubber, this work provides a new way to improve the added value of natural zeolite.
The scope of water and land resource management has been expanded by the interregional trade beyond a single region's boundary along the trans-regional production chain, and the nexus thinking facilitate the understanding of the multi-resource interrelationships and interactions. For the investigation of the water-land nexus, besides the consideration of land use, this study first considered the soil erosion caused by agricultural activities to reveal the water-land nexus from both land cover and soil layer perspectives. The integrated nexus strength (INS) indicator combining with linkage analysis was introduced to detect the distant connections of water and land in ten counties and one city of the Heihe River Basin in Northwestern China. The results show that, from the regional perspective, Minle and Ganzhou in the middle reaches of the Heihe River Basin were essential regions for the water-land nexus, as they imported and exported products embodied with intensive water resource, land use, and soil erosion. Suzhou was the major net importer with imports from counties in middle reaches, including Gaotai, Linze, Ganzhou, and Minle. Jinta, located in the downstream of the Heihe River Basin, faced with serious water scarcity, land desertification, and soil erosion problems, still exported large amounts of agricultural products embodied with numerous resources. From sectoral perspective, the Grain Crops and Cash Crops sectors in the middle reaches had higher values of INS-net forward linkage (export direction), due to that the agricultural sector was primary resource consumers in supply chains to support the following production processes. For INS-net backward linkage (import direction), the Foods and Services sectors in the middle reaches were the dominant sectors, in the reason that food processing and service production processes required more primary products with intensive embodied resources to fulfill their production activities.
Global analyses have revealed virtual drains and gains of water between trading countries, with Mexico ranking as one of the countries with the fastest increase in unsustainable water consumption in agriculture for export markets, since 2000. It is unclear, however, how Mexico has reshaped its crop production and associated reliance on freshwater resources to satisfy growing domestic and international markets, especially the United States (US). While the Mexico-US partnership has been identified as one supported by unsustainable irrigation water, the spatial understanding of its strain on water resources has remained at the national scale and without context of the crops driving the change. In this analysis, we focus on the evolution of Mexican agriculture since 1994, the year the North American Free Trade Agreement was enacted, to identify hotspots of water unsustainability in crop production in the domestic and US supply chain. Using a global process-based crop water model, we find that between 1994 and 2015, rainwater (or ‘green’ water) and irrigation (or ‘blue’) water consumed in the production of crops increased by one fourth nationally, while water in crops exported to the US doubled. Virtual export of blue water embodied in the trade of berries increased five orders of magnitude; a substantial growth in blue water export was also associated with trade to the US of cereals, fruits, nuts, vegetables, pulses, and tubers. Our results show that in Mexico irrigated water plays an increasingly prominent role in export agriculture, and that many healthy crops that dominate US imports from the world are grown in water scarce Mexican municipalities relying on unsustainable irrigation practices. This serves as a warning for the sustainability of future Mexican healthy food supplies, both for the domestic market and for export to the US.
One of the main challenges for India is increasing food security and promoting economic development using the domestic finite and already stressed natural resources. In the last decades silk production has been booming in India in response to the 2025 silk self-sufficiency goal set by the Indian Ministry of Textile. It is not clear to which extent mulberry (Morus alba), used to feed silkworm in 70% of the total domestic silk production, can be expanded in the wastelands identified by the Indian Government as suitable for moriculture without both endangering natural resources and causing competition for natural resources with the food sector.
This issue is here investigated by a) assessing mulberry water consumption (rain and irrigation) in the plantations presently cultivated and in all the wastelands selected by the government for the expansion of moriculture as well; b) analysing annual and sub-annual water scarcity induced by mulberry plantations within the plantations; c) studying the potential competition for natural resources between food crops and mulberry. To this end the dynamic spatially distributed crop water balance WATNEEDS model has been used to analyze two different scenarios being the reference scenario considering the present climate and land cover, and the “silk expansion scenario” combining present climate and the new mulberry plantations. Results for the reference scenario show mulberry expansion areas already suffering food insecurity and water scarcity in the dry period. Here, the expansion of mulberry cultivation is shown to exacerbate water scarcity in pre-monsoon months especially in the North-Eastern Region affecting on a yearly scale eleven million people. Results also show expanding food production on wastelands rather than mulberry could be a viable solution for alleviating the burden of malnutrition.
Natural rubber development is facing sustainability challenges, such as price volatility, human rights violations, deforestation, and biodiversity loss. There is a lack of valid measurement attributes to assess sustainable natural rubber development. This study contributes to the literature by providing a set of sustainable natural rubber development attributes and determining a model of their causal interrelationships based on qualitative information. A mixed-method approach comprising the fuzzy Delphi method and the fuzzy decision-making trial and evaluation technique is used to validate and map the attributes in the model. The findings indicate that technical support has the most significant influence on preventing the economic and social risks involved in natural rubber development. Furthermore, environmental sustainability and economic sustainability interact, and one cannot be achieved without the other. Promoting value addition, natural rubber quality, capital investment, marketing platforms, alternative income sources, attitudes towards change, and material consumption are significant criteria identified as priorities to enhance smallholder producers’ sustainability. Theoretical and managerial implications are provided.
Given the large amounts of water, land, and food embodied in the trade of goods and services, a key step in decoupling extensive resource consumption from the economic system is to understand the full impact of socioeconomic development on the water-land-food nexus. This study integrates input–output analysis, ecological network analysis, and Dempster–Shafer evidence theory into a supernetwork model to detect the water-land-food nexus among economic sectors with an aim to explore effective strategic paths for resource management and to facilitate the construction of a resource-saving society. Results show that most sectors of China are resource inefficient and that all resource systems are unsustainable as reflected in the low performance of their Finn’s cycling index and system robustness. Meanwhile, results of flow networks analysis show an extremely uneven land resource allocation where more than 94% of the land used in China is classified as direct agricultural land. The water-land-food nexus can gain resource saving bonus via enhancing the robustness of economy. However, the co-benefits from the nexus are negligibly small for the resource utilization efficiency. The results also indicate that the relevant resource-saving policies on food and water are highly likely to gain resource co-benefits due to their similarities in sectoral importance. Correspondingly, a set of strategic measures, including adopting a tiered resource price, deepening industrial convergence of agriculture, enhancing agriculture-food nexus, and managing water or land use from the food consumer side, are designed to build a resource-saving society. The findings of this study can provide additional insights into the impacts of the economy on the water-land-food nexus, which is beneficial for achieving an efficient and coordinated management of resources.
This paper contributes to debates on the implications of land-based investments on local livelihoods in the Global South. Drawing on a comprehensive national dataset on land concessions in Laos, and 2005 and 2015 village-level poverty rates, we examine the association between land-based investments and poverty at the village level in Lao rural areas. Results outline contexts in which land-based investments have either positive or adverse association with village-level poverty change rates; they also reveal factors that determine village-level poverty reduction in Laos. Our results suggest that poverty rates in villages affected by land-based investments decreased significantly between 2005 and 2015, following the national trend in Laos. However, in cases where land-based investments caused more farmland loss, poverty reduction was low or poverty rates increased over this period. Results further reveal that land-based investments implemented in more remote areas or poorer villages had a stronger association with poverty reduction. However, poverty was not a central consideration for the establishment of land-based investments. Our findings fill an important gap, providing a middle-level analysis from which grounded observations are analyzed alongside national trends.
Accurately assessing green and blue water requirements from croplands is fundamental to promote sustainable water management. In the last decade, global hydrological models have provided important insights into global patterns of water requirements for crop production. As important as these models are, they do not provide monthly crop-specific and year-specific data of green and blue water requirements. Gridded crop-specific products are therefore needed to better understand the spatial and temporal evolution of water demand. Here, we present a global gridded database of monthly crop-specific green (rain-fed) and blue (irrigated) water requirements for 23 main crops and 3 crop groups obtained using our WATNEEDS model. For the time periods in which our dataset matched, these estimates are validated against existing global products and satellite based datasets of evapotranspiration. The data are publicly available and can be used by practitioners in the water-energy-food nexus to assess the water sustainability of our food and energy systems at multiple spatial (local to global) and temporal (seasonal to multi-year) scales.
Water scarcity raises major concerns on the sustainable future of humanity and the conservation of important ecosystem functions. To meet the increasing food demand without expanding cultivated areas, agriculture will likely need to introduce irrigation in croplands that are currently rain-fed but where enough water would be available for irrigation. "Agricultural economic water scarcity" is, here, defined as lack of irrigation due to limited institutional and economic capacity instead of hydrologic constraints. To date, the location and productivity potential of economically water scarce croplands remain unknown. We develop a monthly agrohydrological analysis to map agricultural regions affected by agricultural economic water scarcity. We find these regions account for up to 25% of the global croplands, mostly across Sub-Saharan Africa, Eastern Europe, and Central Asia. Sustainable irrigation of economically water scarce croplands could feed an additional 840 million people while preventing further aggravation of blue water scarcity.
Interregional trade can potentially extend the management of scarce resources beyond a region’s territory along supply chains. Here we combined the multi-regional input-output model with structural decomposition analysis to reveal the distant connections of agricultural land and water use as well as the drivers behind their variations in China. Our results show that trade-embodied agricultural land use increase by 2.3-fold and 2.5-fold for virtual agricultural water use flows from 2002 to 2012. The water-starved northern China with abundant agricultural land is the main exporter of virtual (also called trade-embodied) agricultural land and water. Moreover, the role of the virtual water use importers and exporters were determined by the availability of land, rather than water resources. Based on scenario analysis, we found that if agricultural water use efficiency of north China reached the world’s top-level but agricultural land use efficiency remained unchanged, the virtual water flows would be reduced by 32% and only water resources, not agricultural land, would be able to sustain future economic development. Our findings may provide significant information for potential solutions to China’s regional water shortage from a land-water nexus perspective.
Urban water governance is a framework for addressing critical issues in cities’ water resources by creating a more inclusive policy for sustainable transitions. Beyond the physical or direct water resources available to cities, there are water resources embedded within the imported food, energy, electricity, and other materials required for urban life and growth. Combined, these two types of water resources create the water footprint of a city. Expanding the framework of urban water governance to promote a sustainable water footprint is necessary for advancing urban environments in the face of climate change and resource constraints. We discuss the need for open-access data to transition toward a sustainable urban water governance system, considering both direct and indirect resources. This discussion builds on existing literature and asserts a broader goal of achieving a blue city. To this end, we identify a few attributes of the Boston, Massachusetts Metropolitan Area to highlight data and governance opportunities for both its direct and indirect water resources.
In the generation of electricity, water is consumed through cooling of thermoelectric power plants and evaporation behind hydroelectric dams before flowing throughout the physical electric grid as an embedded resource. In the European electric grid, there are significant amounts of electricity resources traded between countries to balance power demands, creating a virtual water trade network. To understand the scale and burden shift of this virtual water trade, we create a resource accounting model that couples embedded water resources with international electricity trade throughout Europe at a sub-annual time-scale. Using data from the European Network of Transmission System Operators for Electricity, we identify an increase of virtual water trade from 43 million m³ to 49 million m³ between 2010 and 2017, with significant seasonal variation. We further contextualize these temporal variations of virtual water trade through an analysis of changing electricity policies in three countries (Italy, Great Britain, and Germany) and their subsequent effects on virtual water trade. In developing this virtual water network, we identify significant data gaps that lead to uncertainty and create challenges for decision-making, suggesting the need for a comprehensive data collection plan on the impact of energy on water resources across Europe.
Climate change is an actual fact setting off an imbalance in many living systems. Among these affected systems, water is a major essential element in the globe and in every existing living being. Therefore, several complications have been stated to occur, following water scarcity and water flood in many regions of the world, which make of them a global major threat of water security. The global disease burden is an additional factor that appeals to serious interventions worldwide in order to alleviate the water scarcity and water flood-related effects.
The increasing global demand for farmland products is placing unprecedented pressure on the global agricultural system and its water resources. Many regions of the world, that are affected by a chronic water scarcity relative to their population, strongly depend on the import of agricultural commodities and associated embodied (or virtual) water. The globalization of water through virtual water trade (VWT) is leading to a displacement of water use and a disconnection between human populations and the water resources they rely on. Despite the recognized importance of these phenomena in reshaping the patterns of water dependence through teleconnections between consumers and producers, their effect on global and regional water resources has just started to be quantified. This review investigates the global spatiotemporal dynamics, drivers, and impacts of VWT through an integrated analysis of surface water, groundwater, and root-zone soil moisture consumption for agricultural production; it evaluates how virtual water flows compare to the major 'physical water fluxes' in the Earth System; and provides a new reconceptualization of the hydrologic cycle to account also for the role of water redistribution by the hidden 'virtual water cycle'.
Water is a major factor limiting crop production in many regions around the world. Irrigation can greatly enhance crop yields, but the local availability and timing of freshwater resources constrains the ability of humanity to increase food production. Innovations in irrigation infrastructure have allowed humanity to utilize previously inaccessible water resources, enhancing water withdrawals for agriculture while increasing pressure on environmental flows and other human uses. While substantial additional water will be required to support future food production, it is not clear whether and where freshwater availability is sufficient to sustainably close the yield gap in cultivated lands. The extent to which irrigation can be expanded within presently rainfed cropland without depleting environmental flows remains poorly understood. Here we perform a spatially explicit biophysical assessment of global consumptive water use for crop production under current and maximum attainable yield scenarios assuming current cropping practices. We then compare these present and anticipated water consumptions to local water availability to examine potential changes in water scarcity. We find that global water consumption for irrigation could sustainably increase by 48% (408 km3 H2O y-1) – expanding irrigation to 26% of currently rainfed cultivated lands (2.67×106 km2) and producing 37% (3.38×1015 kcal y-1) more calories, enough to feed an additional 2.8 billion people. If current unsustainable blue water consumption (336 km3 y-1) and production (1.19×1015 kcal y-1) practices were eliminated, a sustainable irrigation expansion and intensification would still enable a 24% increase in calorie (2.19×1015 kcal y-1) production. Collectively, these results show that the sustainable expansion and intensification of irrigation in selected croplands could contribute substantially to achieving food security and environmental goals in tandem in the coming decades.
Water availability is a major factor constraining humanity's ability to meet the future food and energy needs of a growing and increasingly affluent human population. Water plays an important role in the production of energy, including renewable energy sources and the extraction of unconventional fossil fuels that are expected to become important players in future energy security. The emergent competition for water between the food and energy systems is increasingly recognized in the concept of the “food‐energy‐water nexus.” The nexus between food and water is made even more complex by the globalization of agriculture and rapid growth in food trade, which results in a massive virtual transfer of water among regions and plays an important role in the food and water security of some regions. This review explores multiple components of the food‐energy‐water nexus and highlights possible approaches that could be used to meet food and energy security with the limited renewable water resources of the planet. Despite clear tensions inherent in meeting the growing and changing demand for food and energy in the 21st century, the inherent linkages among food, water, and energy systems can offer an opportunity for synergistic strategies aimed at resilient food, water, and energy security, such as the circular economy.
Shale deposits are globally abundant and widespread. Extraction of shale oil and shale gas is generally performed through water‐intensive hydraulic fracturing. Despite recent work on its environmental impacts, it remains unclear where and to what extent shale resource extraction could compete with other water needs. Here we consider the global distribution of known shale deposits suitable for oil and gas extraction and develop a water balance model to quantify their impacts on local water availability for other human uses and ecosystem functions. We find that 31‐44% of the world's shale deposits are located areas where water‐stress would either emerge or be exacerbated as a result of shale oil or gas extraction; 20% of shale deposits are in areas affected by groundwater depletion and 30% in irrigated land. In these regions shale oil and shale gas production would likely compete for local water resources with agriculture, environmental flows, and other water needs. By adopting a hydrologic perspective that considers water availability and demand together, decision makers and local communities can better understand the water and food security implications of shale resource development
Following the 2007–2008 surge in international land deals, many analysts have portrayed this moment of agrarian history as a manifestation of the re-emergence of large-scale capitalist farming. However, official national-scale figures concerning key cash crops in Malaysia and Indonesia rather show the growing importance of smallholders. Although these figures must be read with caution, they nevertheless point to a contradiction. This incites us to revisit the debate on the relation between large and small farms using two important sectors, rubber and palm oil, two major plantation crops increasingly cultivated by smallholders. Then, with regard to the cultivation of rubber in Malaysia and Indonesia, we provide a historical perspective on the institutional and economic contexts in which smallholders have managed to cultivate a growing share of plantation crops. For comparative purposes, we attend to the more recent expansion of oil palm in the region, and to how it has led to the emergence of an important population of smallholders, despite policies biased in favor of large-scale plantations. For both crops, we are paying particular attention to national agricultural policies and their impact on the development of smallholder plantation crop production, and to how they influence the respective weight of large and small farms.
Over the past decade, rubber cultivation has expanded throughout the Mekong region, from established centers of production in Thailand, China and Vietnam to new sites in Laos, Myanmar and Cambodia. Rubber has brought opportunities for increased incomes and livelihood improvement as well as social and environmental risks. The2012 drop in rubber prices has sent the sector into disarray, halting the expansion of rubber and constraining the ability of farmers and companies to profit. This study examines how rubber production in Myanmar is governed, especially the socio-ecological dynamics of varying forms of production: smallholding, contract farming and large-scale estate plantations. Based upon an analysis of secondary literature and interviews with key stakeholders, it was found that rubber production in Myanmar is for the most part not green, meaning that it has not reduced poverty and protected ecosystem services and forested areas. The price crash has prevented most smallholding farmers from increasing their income. Wages on large-scale plantations have been low and only a limited amount of work for Myanmar people is available. Large-scale estates have been developed on land expropriated from communities and have replaced forested areas that provide important ecosystem services to local communities. The paper argues that if rubber is to be truly green then significant changes to production and trade must be made, including minimum price supports from the state, appropriate land use planning measures, the establishment of cooperatives, theprotection of community land rights, and the implementation of agroforestry rubber production models.
Over the past decade, rubber cultivation has expanded throughout the Mekong region, from established centers of production in Thailand, China and Vietnam to new sites in Laos, Myanmar and Cambodia. Rubber has brought opportunities for increased incomes and livelihood improvement as well as social and environmental risks. The 2012 drop in rubber prices has sent the sector into disarray, halting the expansion of rubber and constraining the ability of farmers and companies to profit. This study examines how rubber production in the Lao PDR is governed, especially the soci-ecological dynamics of varying forms of production: smallholding, contract farming and large-scale estate plantations. Based upon an analysis of secondary literature and interviews with key stakeholders, it was found that rubber production in the Lao PDR is for the most part not green, meaning that it has not reduced poverty and protected ecosystem services and forested areas. The price crash has prevented most smallholding farmers from increasing their income. Wages on large-scale plantations have been low and only a limited amount of work for Lao people is available. Large-scale estates have been developed on land expropriated from communities and have replaced forested areas that provide important ecosystem services to local communities. The paper argues that if rubber is to be truly green, then significant changes to production and trade must be made, including minimum price supports from the state, appropriate land use planning measures, the establishment of cooperatives, the protection of community land rights, and the implementation of agroforestry rubber production models.
Recent energy security strategies, investment opportunities and energy policies have led to an escalation in biofuel consumption at the expenses of food crops and pastureland. To evaluate the important impacts of biofuels on food security, the food-energy nexus needs to be investigated in the context of its linkages with the overall human appropriation of land and water resources. Here we provide a global assessment of biofuel crop production, reconstruct global patterns of biofuel crop/oil trade and determine the associated displacement of water and land use. We find that bioethanol is mostly produced with domestic crops while 36% of biodiesel consumption relies on international trade, mainly from Southeast Asia. Altogether, biofuels rely on about 2-3% of the global water and land used for agriculture, which could feed about 30% of the malnourished population. We evaluate the food-energy tradeoff and the impact an increased reliance on biofuel would have on the number of people the planet can feed.
Freshwater scarcity is increasingly perceived as a global systemic risk. Previous global water scarcity assessments, measuring water scarcity annually, have underestimated experienced water scarcity by failing to capture the seasonal fluctuations in water consumption and availability. We assess blue water scarcity globally at a high spatial resolution on a monthly basis. We find that two-thirds of the global population (4.0 billion people) live under conditions of severe water scarcity at least 1 month of the year. Nearly half of those people live in India and China. Half a billion people in the world face severe water scarcity all year round. Putting caps to water consumption by river basin, increasing water-use efficiencies, and better sharing of the limited freshwater resources will be key in reducing the threat posed by water scarcity on biodiversity and human welfare.
The P-graph or process graph framework is both a representation and a methodology that can be shown to be extremely useful as a modelling tool in various areas. P-graphs are directed bi-partite graphs that give an unambiguous representation of any process that can be expressed as a network. It is based on rigorous axioms and combinatorial analysis. The result is a maximal structure, solution structures, and an optimal structure of the network for the process of interest. All of these are feasible and meet design requirements. There is freely available software which automates much of the application of the methodology. The P-graph framework is most useful in the initial design phase of a process where the requirements, the feedstocks, the outputs, and the necessary process structure or network may not be precisely defined, but there is a need to generate alternatives which are feasible to start the design process. For this reason, we propose the P-graph framework as an effective means of generating alternative networks which can represent the nexus of energy, water, and food for the purpose of looking for the most cost effective and sustainable options.
Strong international demand for natural rubber is driving expansion of industrial-scale and smallholder monoculture plantations, with >2 million ha established during the last decade. Mainland Southeast Asia and Southwest China represent the epicentre of rapid rubber expansion; here we review impacts on forest ecosystems and biodiversity. We estimate that 4.3 – 8.5 million ha of additional rubber plantations are required to meet projected demand by 2024, threatening significant areas of Asian forest, including many protected areas. Uncertainties concern the potential for yield intensification of existing cultivation to mitigate demand for new rubber area, versus potential displacement of rubber by more profitable oil palm. Our review of available studies indicates that conversion of forests or swidden agriculture to monoculture rubber negatively impacts bird, bat and invertebrate biodiversity. However, rubber agroforests in some areas of Southeast Asia support a subset of forest biodiversity in landscapes that retain little natural forest. Work is urgently needed to: improve understanding of whether land-sparing or land-sharing rubber cultivation will best serve biodiversity conservation, investigate the potential to accommodate biodiversity within existing rubber-dominated landscapes while maintaining yields, and ensure rigorous biodiversity and social standards via the development of a sustainability initiative.This article is protected by copyright. All rights reserved.
Global demands on agricultural land are increasing due to population growth, dietary changes and the use of biofuels. Their effect on food security is to reduce humans’ ability to cope with the uncertainties of global climate change. In light of the 2008 food crisis, to secure reliable future access to sufficient agricultural land, many nations and corporations have begun purchasing large tracts of land in the global South, a phenomenon deemed “land grabbing” by popular media. Because land investors frequently export crops without providing adequate employment, this represents an effective income loss for local communities. We study 28 countries targeted by large-scale land acquisitions [comprising 87 % of reported cases and 27 million hectares (ha)] and estimate the effects of such investments on local communities’ incomes. We find that this phenomenon can potentially affect the incomes of ~12 million people globally with implications for food security, poverty levels and urbanization. While it is important to note that our study incorporates a number of assumptions and limitations, it provides a much needed initial quantification of the economic impacts of large-scale land acquisitions on rural livelihoods.
Electronic supplementary material
The online version of this article (doi:10.1007/s11111-014-0215-2) contains supplementary material, which is available to authorized users.
The recent intensification of international trade has led to a globalization of food commodities and to an increased disconnection between human populations and the land and water resources that support them through crop and livestock production. Several countries are not self-sufficient and depend on imports from other regions. Despite the recognized importance of the role of trade in global and regional food security, the societal reliance on domestic production and international trade remains poorly quantified. Here we investigate the global patterns of food trade and evaluate the dependency of food security on imports. We investigate the relationship existing between the trade of food calories and the virtual transfer of water used for their production. We show how the amount of food calories traded in the international market has more than doubled between 1986 and 2009, while the number of links in the trade network has increased by more than 50%. Likewise, global food production has increased by more than 50% in the same period, providing an amount of food that is overall sufficient to support the global population at a rate of 2700-3000 kcal per person per day. About 23% of the food produced for human consumption is traded internationally. The Water Use Efficiency of food trade (i.e., food calories produced per unit volume of water used) has declined in the last few decades. The water use efficiency of food production overall increases with the countries’ affluence; this trend is likely due to the use of more advanced technology.
The increasing demand for agricultural products and the uncertainty of international food markets has recently drawn the attention of governments and agribusiness firms toward investments in productive agricultural land, mostly in the developing world. The targeted countries are typically located in regions that have remained only marginally utilized because of lack of modern technology. It is expected that in the long run large scale land acquisitions (LSLAs) for commercial farming will bring the technology required to close the existing crops yield gaps. While the extent of the acquired land and the associated appropriation of freshwater resources have been investigated in detail, the amount of food this land can produce and the number of people it could feed still need to be quantified. Here we use a unique dataset of land deals to provide a global quantitative assessment of the rates of crop and food appropriation potentially associated with LSLAs. We show how up to 300–550 million people could be fed by crops grown in the acquired land, should these investments in agriculture improve crop production and close the yield gap. In contrast, about 190–370 million people could be supported by this land without closing of the yield gap. These numbers raise some concern because the food produced in the acquired land is typically exported to other regions, while the target countries exhibit high levels of malnourishment. Conversely, if used for domestic consumption, the crops harvested in the acquired land could ensure food security to the local populations.
Whether rubber plantations have the role of water pumps in tropical
Southeast Asia is under active debate. Fifteen years (1994-2008)
of paired catchments water observation data and one year paired eddy
covariance water flux data in primary tropical rain forest and tropical
rubber plantation was used to clarify how rubber plantation affects
local water resources of Xishuangbanna, China. Both catchment water
observations and direct eddy covariance estimates indicates that more
water was evapotranspired from rubber plantation (1137 mm based on
catchment water balance, 1125 mm based on eddy covariance) than from the
rain forest (969 mm based on catchment water balance, 927 mm based on
eddy covariance). Soil water storage during the rainy season is not
sufficient to maintain such high evapotranspiration rates, resulting in
zero flow and water shortages during the dry season in the rubber
plantation. Therefore, this study supports the idea that rubber
plantations act as water pumps as suggested by local inhabitants.
Expanding global and regional markets are driving the conversion of traditional subsistence agricultural and occupied non-agricultural lands to commercial-agricultural purposes. In many parts of mainland Southeast Asia rubber plantations are expanding rapidly into areas where the crop was not historically found. Over the last several decades more than one million hectares of land have been converted to rubber trees in areas of China, Laos, Thailand, Vietnam, Cambodia and Myanmar, where rubber trees were not traditionally grown. This expansion of rubber plantations has replaced ecologically important secondary forests and traditionally managed swidden fields and influenced local energy, water and carbon fluxes. Accurate and up-to-date monitoring and mapping of rubber tree growth is critical to understanding the implications of this changing ecosystem. Discriminating rubber trees from second-growth forests and fallow land has proven challenging. Previous experiments using machine-learning approaches with hard classifications on remotely sensed data, when faced with the realities of a heterogeneous plant-life mixture and high intra-class variance, have tended to overestimate the areas of rubber tree growth. Our current research sought to: 1) to investigate the potential of using a Mahalanobis typicality model to deal with mixed pixels; and 2) to explore the potential for combining MOderate Resolution Imaging Spectroradiometer (MODIS) imagery with sub-national statistical data on rubber tree areas to map the distribution of rubber tree growth across this mainland Southeast Asia landscape. Our study used time-series MODIS Terra 16-day composite 250 m Normalized Difference Vegetation Index (NDVI) products (MOD13Q1) acquired between March 2009 and May 2010. We used the Mahalanobis typicality method to identify pixels where rubber tree growth had the highest probability of occurring and sub-national statistical data on rubber tree growth to quantify the number of pixels of rubber tree growth mapped per administrative unit. We used Relative Operating Characteristic (ROC) and error matrix analysis, respectively, to assess the viability of Mahalanobis typicalities and to validate classification accuracy. High ROC values, over 0.8, were achieved with the Mahalanobis typicality images of both mature and young rubber trees. The proposed method greatly reduced the commission errors for the two types of rubber tree growth to 1.9% and 2.8%, respectively (corresponding to user’s accuracies of 98.1% and 97.2%, respectively). Results indicate that integrating Mahalanobis typicalities with MODIS time-series NDVI data and sub-national statistics can successfully overcome the earlier overestimation problem.
The water footprint concept has been developed in order to have an indicator of water use in relation to consumption of people. The water footprint of a country is defined as the volume of water needed for the production of the goods and services consumed by the inhabitants of the country. Closely linked to the water footprint concept is the virtual water concept. Virtual water is defined as the volume of water required to produce a commodity or service. International trade of commodities implies flows of virtual water over large distances. The water footprint of a nation can be assessed by taking the use of domestic water resources, subtract the virtual water flow that leaves the country and add the virtual water flow that enters the country. The internal water footprint of a nation is the volume of water used from domestic water resources to produce the goods and services consumed by the inhabitants of the country. The external water footprint of a country is the volume of water used in other countries to produce goods and services imported and consumed by the inhabitants of the country. The study aims to calculate the water footprint for each nation of the world for the period 1997-2001.
The global trade of goods is associated with a virtual transfer of the water required for their production. The way changes in trade affect the virtual redistribution of freshwater resources has been recently documented through the analysis of the virtual water network. It is, however, unclear how these changes are contributed by different types of products and regions of the world. Here we show how the global patterns of virtual water transport are contributed by the trade of different commodity types, including plant, animal, luxury (e.g., coffee, tea, and alcohol), and other products. Major contributors to the virtual water network exhibit different trade patterns with regard to these commodity types. The net importers rely on the supply of virtual water from a small percentage of the global population. However, discrepancies exist among the different commodity networks. While the total virtual water flux through the network has increased between 1986 and 2010, the proportions associated with the four commodity groups have remained relatively stable. However, some of the major players have shown significant changes in the virtual water imports and exports associated with those commodity groups. For instance, China has switched from being a net exporter of virtual water associated with other products (non-edible plant and animal products typically used for manufacturing) to being the largest importer, accounting for 31% of the total water virtually transported with these products. Conversely, in the case of The United states of America, the commodity proportions have remained overall unchanged throughout the study period: the virtual water exports from The United States of America are dominated by plant products, whereas the imports are comprised mainly of animal and luxury products.
A new version of a digital global map of irrigation areas was developed
by combining irrigation statistics for 10825 sub-national statistical
units and geo-spatial information on the location and extent of
irrigation schemes. The map shows the percentage of each 5 arc minute by
5 arc minute cell that was equipped for irrigation around the year 2000.
It is thus an important data set for global studies related to water and
land use. This paper describes the data set and the mapping methodology
and gives, for the first time, an estimate of the map quality at the
scale of countries, world regions and the globe. Two indicators of map
quality were developed for this purpose, and the map was compared to
irrigated areas as derived from two remote sensing based global land
cover inventories. We plan to further improve that data set; therefore
comments, information and data that might contribute to that effort are
highly welcome.
Societal pressure on the global land and freshwater resources is increasing as a result of the rising food demand by the growing human population, dietary changes, and the enhancement of biofuel production induced by the rising oil prices and recent changes in United States and European Union bioethanol policies. Many countries and corporations have started to acquire relatively inexpensive and productive agricultural land located in foreign countries, as evidenced by the dramatic increase in the number of transnational land deals between 2005 and 2009. Often known as "land grabbing," this phenomenon is associated with an appropriation of freshwater resources that has never been assessed before. Here we gather land-grabbing data from multiple sources and use a hydrological model to determine the associated rates of freshwater grabbing. We find that land and water grabbing are occurring at alarming rates in all continents except Antarctica. The per capita volume of grabbed water often exceeds the water requirements for a balanced diet and would be sufficient to improve food security and abate malnourishment in the grabbed countries. It is found that about 0.31 × 10(12) m(3)⋅y(-1) of green water (i.e., rainwater) and up to 0.14 × 10(12) m(3)⋅y(-1) of blue water (i.e., irrigation water) are appropriated globally for crop and livestock production in 47 × 10(6) ha of grabbed land worldwide (i.e., in 90% of the reported global grabbed land).
Crop inventory, botanical surveys, and questionnaire investigations of 60% of households in Daka from 1998 to 2004 (a Hani nationality village in the mountainous region of Xishuangbanna) were undertaken. We focused on virtual extinction of agrobiodiversity in smallholder rubber plantations, which have improved smallholder livelihoods but have affected land-use strategies. Income per capita has increased from US$128.3 in 1998 to US$561.7 in 2004 because of an increase of income from rubber from US$75.8 in 1998 to US$451.4 in 2004. The number of cultivated upland rice varieties decreased from seven in 2001 to one in 2004 because of a sharp increase in rubber price after 2002. Rubber plantations increased from 17.7 ha in 1998 to 82.2 ha in 2004, while swidden fields decreased from 20.4 ha in 1998 to 12.7 ha in 2004. It appears that traditional upland rice production and number of varieties is being seriously eroded by encroachment from rubber plantation. Stabilization of agrobiodiversity loss is necessity while still improving the rural economy.
The rubber tree is native to the humid tropics and has traditionally been cropped in the equatorial zone between 10°N and 10°S; in mainland Southeast Asia this includes portions of southern Thailand, south-eastern Vietnam, and southern Myanmar. In the early 1950s, the Chinese government began to invest in growing rubber in environments perceived to be ecologically marginal and eventually established state rubber plantations in areas that lie as far north as 22° north latitude. China’s success in growing rubber in these ‘non-traditional’ environments expanded the habitat in which rubber could be planted and pushed it further north. Today entrepreneurs from China, Vietnam, Malaysia, and Thailand are investing in rubber plantations in areas of Laos, Cambodia, and Myanmar, northwest Vietnam, northeast Thailand, and Yunnan, China. The impact of rubber on smallholders, however, is not yet clear. Experiences in Xishuangbanna, Yunnan, China and northeast Thailand clearly show that smallholder rubber production is a viable and effective proposition in moving households and communities out of poverty. By contrast in countries such as Laos, Cambodia and Myanmar many farmers are struggling to maintain their lands and forests in the face of growing pressures from investors and government institutions to impose concession arrangements.
As the economies of developing countries grow, and the purchasing power of their inhabitants increases, the pressure on the environment and natural resources will continue to increase. In the specific case of China, impressive economic growth during the last decades exemplifies this process. Specifically, we focus on how changing economic dynamics are influencing land-use and land-cover change in Xishuangbanna, China. Xishuangbanna has the richest flora and fauna of China, but increasing demand for natural rubber and the expansion of rubber plantations is threatening this high-diversity region. We quantified land-use/land-cover change across Xishuangbanna using Landsat images from 1976, 1988, and 2003. The most obvious change was the decrease in forest cover and an increase in rubber plantations. In 1976, forests covered approximately 70% of Xishuangbanna, but by 2003 they covered less than 50%. Tropical seasonal rain forest was the forest type most affect by the expansion of rubber plantations, and a total of 139,576 ha was lost. The increase of rubber plantations below 800 m, shifted agricultural activities to higher elevations, which resulted in deforestation of mountain rain forest and subtropical evergreen broadleaf forest. Although these changes have affected the biodiversity and ecosystem services, we believe that long-term planning and monitoring can achieve a balance between economic and social needs of a growing population and the conservation of a highly diverse flora and fauna. Below 800 m , we recommend that no more rubber plantations be established, existing forest fragments should be protected, and riparian forests should be restored to connect fragments. Future rubber plantations should be established in the abandoned arable or shrublands at higher elevations, and tea or other crops should be planted in the understory to improve economic returns and reduce erosion.
We used the conversion of land use and its effects (CLUE-s) model to simulate scenarios of land-cover change in Montane mainland southeast Asia (MMSEA), a region in the midst of transformation due to rapid intensification of agriculture and expansion of regional trade markets. Simulated changes affected approximately 10 % of the MMSEA landscape between 2001 and 2025 and 16 % between 2001 and 2050. Roughly 9 % of the current vegetation, which consists of native species of trees, shrubs, and grasses, is projected to be replaced by tree plantations, tea, and other evergreen shrubs during the 50 years period. Importantly, 4 % of this transition is expected to be due to the expansion of rubber (Hevea brasiliensis), a tree plantation crop that may have important implications for local-to-regional scale hydrology because of its potentially high water consumption in the dry season.
We describe the construction of a 10′ latitude/longitude data set of mean monthly surface climate over global land areas, excluding Antarctica. The climatology includes 8 climate elements-precipitation, wet-day frequency, temperature, temperature, diurnal temperature range, relative humidity, sunshine duration, ground frost frequency and windspeed-and was interpolated from a data set of station means for the period centred on 1961 to 1990. Precipitation was first defined in terms of the parameters of the Gamma distribution, enabling the calculation of monthly precipitation at any given return period. The data are compared to an earlier data set at 0.5° latitude/longitude resolution and show added value over most regions. The data will have many applications in applied climatology, biogeochemical modelling, hydrology and agricultural meteorology and are available through the International Water Management Institute World Water and Climate Atlas (http://www.iwmi.org) and the Climatic Research Unit (http://www.cru.uea.ac.uk).
Rubber plantations are expanding rapidly throughout montane mainland Southeast Asia ( 1 – 3 ). More than 500,000 ha may have been converted already in the uplands of China, Laos, Thailand, Vietnam, Cambodia, and Myanmar (see the figure, panel A). By 2050, the area of land dedicated to rubber and other diversified farming systems could more than double or triple, largely by replacing lands now occupied by evergreen broadleaf trees and swidden-related secondary vegetation ( 2 ). What are the environmental consequences of this conversion of vast landscapes to rubber?
Rubber and crude palm oil (CPO) are the major agricultural products of Thailand. This work aimed at evaluating the ecological footprint (EF) of ribbed smoked sheet (RSS) from cooperative rubber sheet factories, ribbed smoked sheet bale (RSSB) from large rubber sheet factories, Standard Thai Rubber (STR) from block rubber factories, concentrated latex from concentrated latex factories, and CPO of palm oil mills in Thailand. The system boundary of cradle to gate was set according to the life cycle assessment approach. The fresh latex and cup lump from rubber plantations and fresh fruit bunch from the oil palm plantations were the major inputs for the rubber factory and the palm oil mill, respectively. EFs of the selected products from high to low were STR 20 at 7.06 global hectares (gha)/tonne, RSSB at 6.87 gha/tonne, RSS at 6.78 gha/tonne, STR 5 at 6.68 gha/tonne, concentrated latex at 5.07 gha/tonne, and CPO at 4.34 gha/tonne, on average. The EF of forest for production of fresh latex, cup lump and unsmoked sheet, and fresh fruit bunch accounted for more than 92% of the total EF. The EF for processing was quite less for the products of both rubber factories and palm oil mills. The production of RSS had a high potential for reducing the EF, followed by that of concentrated latex and STR, respectively. In 2015, the total EF for the production of rubber products and CPO in Thailand was 35.2 and 30.5 million gha for the average and best observed scenarios, respectively. The alternative methods for reduction of EF should be emphasized. The policy makers should include the EF values as the indicator for supporting the expansion of rubber and oil palm industries.
Pressure on agricultural land has markedly increased since the start of the century, driven by demographic growth, changes in diet, increasing biofuel demand, and globalization. To better ensure access to adequate land and water resources, many investors and countries began leasing large areas of agricultural land in the global South, a phenomenon often termed “large-scale land acquisition” (LSLA). To date, this global land rush has resulted in the appropriation of 41million hectares and about 490km3 of freshwater resources, affecting rural livelihoods and local environments. It remains unclear to what extent land and water acquisitions contribute to the emergence of water-stress conditions in acquired areas, and how these demands for water may be impacted by climate change. Here we analyze 18 African countries – 20Mha (or 80%) of LSLA for the continent – and estimate that under present climate 210km3yr−1of water would be appropriated if all acquired areas were actively under production. We also find that consumptive use of irrigation water is disproportionately contributed by water-intensive biofuel crops. Using the IPCCA1B scenario, we find only small changes in green (-1.6%) and blue (+2.0%) water demand in targeted areas. With a 3°C temperature increase, crop yields are expected to decrease up to 20% with a consequent increase in the water footprint. When the effect of increasing atmospheric CO2concentrations is accounted for, crop yields increase by as much as 40% with a decrease in water footprint up to 29%. The relative importance of CO2fertilization and warming will therefore determine water appropriations and changes in water footprint under climate change scenarios.
To investigate the effects of expanding rubber (Hevea brasiliensis) cultivation on water cycling in Mainland Southeast Asia (MSEA), evapotranspiration (ET) was measured within rubber plantations at Bueng Kan, Thailand, and Kampong Cham, Cambodia. After energy closure adjustment, mean annual rubber ET was 1,211 and 1,459 mm/yr at the Thailand and Cambodia sites, respectively, higher than that of other tree-dominated land covers in the region, including tropical seasonal forest (812-1,140 mm/yr), and savanna (538-1,060 mm/yr). The mean proportion of net radiation used for ET by rubber (0.725) is similar to that of tropical rainforest (0.729) and much higher than that of tropical seasonal forest (0.595) and savanna (0.548). Plant area index (varies with leaf area changes), explains 88.2% and 73.1% of the variance in the ratio of latent energy flux (energy equivalent of ET) to potential latent energy flux (LE/LEpot) for midday rain-free periods at the Thailand and Cambodia sites, respectively. High annual rubber ET results from high late dry season water use, associated with rapid refoliation by this brevi-deciduous species, facilitated by tapping of deep soil water, and by very high wet season ET, a characteristic of deciduous trees. Spatially, mean annual rubber ET increases strongly with increasing net radiation (Rn) across the three available rubber plantation observation sites, unlike non-rubber tropical ecosystems, which reduce canopy conductance at high Rn sites. High water use by rubber raises concerns about potential effects of continued expansion of tree plantations on water and food security in MSEA. This article is protected by copyright. All rights reserved.
At first glance, rubber plantations in the Northwest of Vietnam do not appear so different from ‘large-scale land acquisition’, which is quite common in the Global South. However, when we closely examine how many processes in plantations work, we can see that there are many different processes at work besides those that take place in other countries where transnational or domestic corporations purchase or lease land for growing food, fibre or fuel crops. Rubber plantations have been strongly supported by the government and promoted as a way to industrialize and modernize the uplands, while claiming to narrow the economic gap between the uplands and lowlands. Drawing on fieldwork in two villages in Son La, and on a review of policy papers and documents, this paper identifies the political mechanisms and policies that have emerged as critical factors enabling the dispossession of land for the development of a market economy with a socialist orientation in Vietnam. The paper seeks to understand how institutional control over land and over the discussion of political subjects produces control. It argues that land grabs for rubber plantations in Northwest Vietnam are moves to strengthen state sovereignty. This land seizure has indeed created a new way of land governance that hitherto did not exist in Vietnam.
[1] The increasing global demand for food, fibers, and biofuels has made investments in agriculture a priority for some governments and corporations eager to expand their agricultural production while securing good profits. Here we calculate the water appropriation associated with land deals at different negotiation and implementation stages. Using estimates of actual and potential evapotranspiration for the crops planted in the acquired land, we calculate the green and blue water appropriated by land investors under a variety of irrigation scenarios. We also determine the grey water footprint as the amount of water required to dilute to allowable standards the pollution resulting from fertilizer applications. We found that about 380 × 109 m3 yr−1 of rainwater is appropriated with the 43 million ha of reported contract area acquired by agri-investors (>240 × 109 m3 yr−1 in the 29 million ha of foreign acquisitions only). This water would be sufficient to feed ≈ 300–390 million people.
This study investigates the hydrologic implications of land use conversion from native vegetation to rubber (Hevea brasiliensis) in Southeast Asia. The experimental catchment, Nam Ken (69 km2), is located in Xishuangbanna Prefecture (22°N, 101°E), in the south of Yunnan province, in southwestern China. During 2005 and 2006, we collected hourly records of 2 m deep soil moisture profiles in rubber and three native land-covers (tea, secondary forest and grassland), and measured surface radiation above the tea and rubber canopies. Observations show that root water uptake of rubber during the dry season is controlled by day-length, whereas water demand of the native vegetation starts with the arrival of the first monsoon rainfall. The different dynamics of root water uptake in rubber result in distinct depletion of soil moisture in deeper layers. Traditional evapotranspiration and soil moisture models are unable to simulate this specific behaviour. Therefore, a different conceptual model, taking in account vegetation dynamics, is needed to predict hydrologic changes due to land use conversion in the area. Copyright © 2008 John Wiley & Sons, Ltd.
The leaf litter is the major source of soil organic matter in natural and many plantation crop ecosystems. Quantity and quality
of organic matter in a soil ecosystem is of utmost importance in regulating the soil health. Hence assessment of quality of
organic matter input, viz., litter is important and is attempted in this study. The leaf litter of rubber (Hevea brasiliensis), pueraria (Pueraria phaseoloides), mucuna (Mucuna bracteata), teak (Tectona grandis) and forest (mixed species) were analyzed using solid state 13C nuclear magnetic resonance (NMR) to study the relative abundance of different carbon compounds present. The spectra revealed
that litter of all species studied contain relatively larger amounts of polysaccharides compared to other C containing compounds.
Also it could be observed that the alkyl-C to O-alkyl-C ratio of rubber litter was much higher compared to that of others.
Aromatics and carbonyl compounds were also present in all litter species. The resource quality based on alkyl-C to O-alkyl-C
ratio of the litter samples studied can be arranged in the order pueraria > teak > mucuna > forest > rubber. The respiration
rate, substrate induced respiration rate and biomass-C (Cmic) of the litter samples were estimated. It could be observed that litter associated microbial activity decreased as alkyl-C
to O-alkyl-C ratio increased. Resource quality derived from the NMR spectra and the litter biological properties were complementary.
Soil samples (0–15cm) from the five soil ecosystems (rubber, pueraria, mucuna, teak and forest) were analyzed for respiration
rate, substrate induced respiration rate, Cmic, total-C and total-N. The forest soil had higher respiration rate, total-C and total-N compared to cultivated soil systems.
Pueraria, mucuna and teak soils were comparable for their biological properties while rubber soil recorded comparatively lower
microbial activity.
While smallholder development has, in the past, led to reductions in poverty and hunger, does this still apply in today’s more globalized world? This paper reviews the debates on the contemporary role of agriculture in development and the case for small farms in light of the rise of supermarkets, lower commodity prices and liberalized trade, agricultural research funding, environmental change, HIV/AIDS, and changing policy ideas. Although the answers vary greatly by context, for many low-income countries, smallholder development remains a key option. The policy agenda, however, has changed. In addition to providing public goods, the growing challenge is to overcome market failures, which is largely a matter of institutional innovation.
Nature - the world's best science and medicine on your desktop
Feeding the World, Eradicating Hunger
- Fao
FAO, 2009. Feeding the World, Eradicating Hunger, World Summit on Food Security,
Rome.
From Rice to Rubber. Development, Transformation, and Foreign Investment in Northern Laos: an Actor-oriented Approach
- S Haberecht
Haberecht, S., 2009. From Rice to Rubber. Development, Transformation, and
Foreign Investment in Northern Laos: an Actor-oriented Approach.
Virtual water trade. A quantification of virtual water flows between nations in relation to international crop trade International Rubber Study group, 2016. Statistical Summary of World Rubber
- A Y Hoekstra
- P Q Hung
Hoekstra, A.Y., Hung, P.Q., 2002. Virtual water trade. A quantification of virtual
water flows between nations in relation to international crop trade. Value water
Res. Rep. Ser. 11, 166.
International Rubber Study group, 2016. Statistical Summary of World Rubber SituationQ4 2000 e Q1 2016. International Rubber Study group, Singapore.
The Land Matrix Global Observatory Centre de Coop eration Internationale en Recherche Agronomique pour le D evelopement (CIRAD)
- Land Matrix
Land Matrix, 2017. The Land Matrix Global Observatory. International Land Coalition (ILC), Centre de Coop eration Internationale en Recherche Agronomique
pour le D evelopement (CIRAD), Centre for Development and Environment
(CDE), German Institute of Global and Area Studies (GIGA) and Deutsche (GIZ)..
(Accessed October 2016).
An investigation of China's import demand for technically specified natural rubber (TSR) from Thailand
- K Muethaisong
- T Leemanonwarachai
Muethaisong, K., Leemanonwarachai, T., 2014. An investigation of China's import
demand for technically specified natural rubber (TSR) from Thailand. Statistics
3, 1e192.
The water footprint of land grabbing
- M C Rulli
- P Odorico
Rulli, M.C., D'Odorico, P., 2013. The water footprint of land grabbing. Geophys. Res.
Lett. 40 (23), 6130e6135.
Global Agro-ecological Zones Assessment for Agriculture
- G Fischer
- F Nachtergaele
- S Prieler
- H T Van Velthuizen
- L Verelst
- D Wiberg
Fischer, G., Nachtergaele, F., Prieler, S., Van Velthuizen, H.T., Verelst, L., Wiberg, D.,
2008. Global Agro-ecological Zones Assessment for Agriculture (GAEZ 2008).