Expansion Of Rubber Plantations Research Articles

The conversion of tropical forests to rubber plantations accelerates soil acidification and changes the distribution of soil metal ions in topsoil layers

Unprecedented economic growth in Southeast Asia has encouraged the expansion of rubber plantations. This study aimed to clarify the effects of the conversion of tropical forests to rubber plantations on soil acidification processes, exchangeable cations, exchangeable aluminum (Al), available copper (Cu), zinc (Zn), manganese (Mn) and iron (Fe). The results showed that these conversions significantly decreased soil pH, exchangeable Ca, Mg, available Zn, Mn and Fe, and increased exchangeable Al and available Cu in the topsoil layers. In both the rainy and dry seasons, the conversion of tropical forests to mature rubber plantations increased the average soil exchangeable Al by 930.1 and 54.4%, and soil available Cu by 82.7 and 65.8%, and decreased soil pH by 13.4 and 9.9%, soil exchangeable Ca by 70.9 and 79.9%, soil exchangeable Mg by 76.5 and 77.8%, soil available Zn by 73.8 and 51.6%, soil available Mn by 33.1 and 47.5% and soil available Fe by 15.9 and 22.2% in the 0–10 and 10–30cm soil layers, respectively. The change of soil exchangeable Al was greatly affected by soil acidification processes and soil organic carbon, exchangeable Ca, Mg and available Cu was greatly affected by soil acidification processes, as were available Zn, Mn, and Fe by soil organic carbon. The large losses of soil exchangeable Ca, Mg, and available Zn in the rubber plantations limited plant growth. The release of large amounts of exchangeable Al in the rubber plantations not only decreased soil available P but also threatened the safety of the surrounding environment.

After the rubber boom: good news and bad news for biodiversity in Xishuangbanna, Yunnan, China

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 ( 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.

Precarity and Vulnerability: Rubber Plantations in Northern Laos and Northern Shan State, Myanmar

ABSTRACTIn northern Laos and Northern Shan State in Myanmar, there has occurred a rapid expansion of rubber plantations, both by large economic concessions and by smallholder farmers. The impact of the introduction of rubber differs by place. This article analyses the impact of the introduction of rubber in two villages in Northern Shan State and two in Luang Namtha Province, Lao PDR. We differentiate vulnerability and precarity while assessing the changes that women and men have experienced, which allows us to problematise the long-term vulnerability of seemingly well-adapted farming households. We argue that the strategies that farmers have chosen to improve their situation today will lead to unsustainable livelihoods in the long term. We also link the analysis of vulnerability and precarity to changes in household gender relations. Notwithstanding increased precarity, rising household cash incomes and external support have improved women’s position in some places while hardly affecting gender relations in others.

Effect of a rubber plantation on termite diversity in Melawi, West Kalimantan, Indonesia

One of the negative effects of rubber plantation expansion is the loss of biodiversity in the area. One of the widely used rubber plantation systems is rubber forest agroforestry, which is known to have little effect on biodiversity. This study compared termite species in rubber forest with those in the primary forest within Bukit Baka Bukit Raya National Park in Melawi, Indonesia. Two rubber forest sites (newly opened) and unproductive/old rubber forest, were chosen to estimate the long term effects of rubber forest on termite biodiversity. A standardized transect method was used for termite collection. In total, 35 termite species belonging to eight sub families were collected. Termite species richness in the old rubber forest decreased up to 62.5% compared to that in primary forest sites. In the newly opened rubber forest site, termite species richness was only slightly less than that of the primary forest sites. Termite species richness results corresponded with their functional groups, with no soil feeders found in the old rubber forest. Furthermore, the calculation of several diversity indices also confirmed the results. The results indicated that the expansion of rubber forest in the area appears to have adversely affected termite diversity more than expected.

Rubber Boom, Land Use Change and the Implications for Carbon Balances in Xishuangbanna, Southwest China

Rubber farming expansion in Xishuangbanna, in the Upper Mekong region of Southwest China, has resulted in profound land use change and led to the severe degradation of the local environment. This study explores the dynamics of land use change as a result of the rubber boom, examines the factors influencing the heterogeneity in farmers' land allocations for rubber farming, and assesses the implications of this change for the local environment in terms of carbon balances. The analyses use a comprehensive household survey data set of 612 smallholder rubber farmers in Xishuangbanna. The historical data illustrate the trajectory of rubber expansion and land use change over the past three decades. The model of smallholder land allocation for rubber farming suggests its determinants include ethnicity, experience in rubber farming, household wealth, elevation, and several explanatory variables at the village level. A net loss in carbon stocks at the aggregate level was found due to the expansion of rubber plantations. The rubber farming expansion of smallholders outside the natural reserves in Xishuangbanna has led to a carbon loss of approximately 21 Mg/ha/year over the past three decades. The findings complement discussions on the future of the rubber-based land use system and its sustainability in Xishuangbanna and other rubber-growing areas in the Mekong region.

Identifying Establishment Year and Pre-Conversion Land Cover of Rubber Plantations on Hainan Island, China Using Landsat Data during 1987–2015

Knowing the stand age of rubber tree (Hevea brasiliensis) plantations is vitally important for best management practices, estimations of rubber latex yields, and carbon cycle studies (e.g., biomass, carbon pools, and fluxes). However, the stand age (as estimated from the establishment year of rubber plantation) is not available across large regions. In this study, we analyzed Landsat time series images from 1987–2015 and developed algorithms to identify (1) the establishment year of rubber plantations; and (2) the pre-conversion land cover types, such as old rubber plantations, evergreen forests, and cropland. Exposed soil during plantation establishment and linear increases in canopy closure during non-production periods (rubber seedling to mature plantation) were used to identify the establishment year of rubber plantations. Based on the rubber plantation map for 2015 (overall accuracy = 97%), and 1981 Landsat images since 1987, we mapped the establishment year of rubber plantations on Hainan Island (R2 = 0.85/0.99, and RMSE = 2.34/0.54 years at pixel/plantation scale). The results show that: (1) significant conversion of croplands and old rubber plantations to new rubber plantations has occurred substantially in the northwest and northern regions of Hainan Island since 2000, while old rubber plantations were mainly distributed in the southeastern inland strip; (2) the pattern of rubber plantation expansion since 1987 consisted of fragmented plantations from smallholders, and there was no tendency to expand towards a higher altitude and steep slope regions; (3) the largest land source for new rubber plantations since 1988 was old rubber plantations (1.26 × 105 ha), followed by cropland (0.95 × 105 ha), and evergreen forests (0.68 × 105 ha). The resultant algorithms and maps of establishment year and pre-conversion land cover types are likely to be useful in plantation management, and ecological assessments of rubber plantation expansion in China.

Tipping Points in the Supply of Ecosystem Services of a Mountainous Watershed in Southeast Asia

Rubber plantations have expanded at an unprecedented rate in Southeast Asia in recent decades. This has led to a substantial decline in the supply of ecosystem services (ESS) and has reduced livelihood options and socioeconomic well-being in rural areas. We assessed the impact of two land use scenarios on the supply of ESS in a mountainous watershed in Xishuangbanna Prefecture, People’s Republic of China. We combined time-series data derived from spatially explicit ESS models (InVEST) with a sequential, data-driven algorithm (R-method) to identify potential tipping points (TPs) in the supply of ESS under two rubber plantation expansion scenarios. TPs were defined as any situation in which the state of a system is changed through positive feedback as a result of accelerating changes. The TP analysis included hydrological, agronomical, and climate-regulation ESS, as well as multiple facets of biodiversity (habitat quality for vertebrate, invertebrate, and plant species). We identified regime shifts indicating potential tipping points, which were linked to abrupt changes in rubber yields, in both scenarios at varying spatial scales. With this study, we provide an easily applicable method for regional policy making and land use planning in data-scarce environments to reduce the risk of traversing future TPs in ESS supply for rubber producing land use systems.

ENTREPREUNARIAL AND FAMILY BUSINESS FARMS IN THAILAND: WHO TOOK ADVANTAGE OF THE RUBBER BOOM?

Following the high rubber prices in the second half of the 2010s, rubber plantations expanded greatly especially in Southeast Asia. Smallholders were important actors of the recent rubber boom. However, large landholdings and foreign investments were also very present in some Southeast Asian rubber producing countries leading some researchers to ask whether we are witnessing resurgence of plantations in tropical Asia. Looking at entrepreneurial rubber farms in Thailand, the first producer of natural rubber in the world, where very little information is available on this type of farms, is one way to contribute to the debate. After identifying large rubber holdings using secondary data completed by some field explorations, we conducted a survey on a limited number (13) of large rubber holdings. Qualitative analysis revealed that the recent development of large plantations in the rubber sector was actually limited in Thailand, and that this (limited) expansion of large rubber plantations mainly involved family business farms. Together with family farms, these family business farms largely contributed to the recent expansion of rubber plantations rather than entrepreneurial farms. In addition, these large landholdings shared several similar technical and organizational patterns with smaller family farms. Finally, Thailand represents a specific pattern of change in farm structure in which family farms have always persisted over enterprise farms. Family business farms are a type of farm structure that now appears to be expanding. In addition to continuing to support small and medium family farms, government policies should consider such changes in farm structure and provide support to improve the technical management of these developing forms of production. In parallel, support should be provided to help maintain the smallholdings thereby limiting land concentration when it is not wanted by the owners.

Expansion dynamics of deciduous rubber plantations in Xishuangbanna, China during 2000–2010

Monoculture rubber plantations have been replacing tropical rain forests substantially in Southern China and Southeast Asia over the past several decades, which have affected human wellbeing and ecosystem services. However, to the best of our knowledge on the extent of rubber plantation expansion and their stand ages is limited. We tracked the spatiotemporal dynamics of deciduous rubber plantations in Xishuangbanna, the second largest natural rubber production region in China, from 2000 to 2010 using time-series data from the Phased Array type L-band Synthetic Aperture Radar (PALSAR), Landsat, and Moderate Resolution Imaging Spectroradiometer (MODIS). We found that rubber plantations have been expanding across a gradient from the low-elevation plains to the high elevation mountains. The areas of deciduous rubber plantations with stand ages ≤5, 6–10, and ≥11-year old were ~1.2 × 105 ha, ~0.8 × 105 ha, and ~2.9 × 105 ha, respectively. Older rubber plantations were mainly located in low-elevation and species-rich regions (500–900 m) and younger rubber trees were distributed in areas of relative high-elevation with fragile ecosystems. Economic and market factors have driven the expansion of rubber plantations, which is not only a threat to biodiversity and environmental sustainability, but also a trigger for climatic disasters. This study illustrates that the integration of microwave, optical, and thermal data is an effective method for mapping deciduous rubber plantations in tropical mountainous regions and determining their stand ages. Our results demonstrate the spatiotemporal pattern of rubber expansions over the first decade of this century.

Determining carnivore habitat use in a rubber/forest landscape in Brazil using multispecies occupancy models.

Understanding the factors that influence the presence and distribution of carnivores in human-dominated agricultural landscapes is one of the main challenges for biodiversity conservation, especially in landscapes where setting aside large protected areas is not feasible. Habitat use models of carnivore communities in rubber plantations are lacking despite the critical roles carnivores play in structuring ecosystems and the increasing expansion of rubber plantations. We investigated the habitat use of a mammalian carnivore community within a 4,200-ha rubber plantation/forest landscape in Bahia, Brazil. We placed two different brands of camera traps in a 90-site grid. We used a multispecies occupancy model to determine the probabilities of habitat use by each species and the effect of different brands of camera traps on their detection probabilities. Species showed significant differences in habitat use with domestic dogs (Canis familiaris) and crab-eating foxes (Cerdocyon thous) having higher probabilities of using rubber groves and coatis (Nasua nasua) having a higher probability of using forest. The moderate level of captures and low detection probabilities (≤ 0.1) of tayras (Eira barbara) and wildcats (Leopardus spp.) precluded a precise estimation of habitat use probabilities using the multispecies occupancy model. The different brands of camera traps had a significant effect on the detection probability of all species. Given that the carnivore community has persisted in this 70-year-old landscape, the results show the potential of rubber/forest landscapes to provide for the long-term conservation of carnivore communities in the Atlantic forest, especially in mosaics with 30–40% forest cover and guard patrolling systems. The results also provide insights for mitigating the impact of rubber production on biodiversity.

Recognizing the Rapid Expansion of Rubber Plantation – A Threat to Native Forest in Parts of Northeast India

With the current trend of land use/land cover (LULC) change taking place globally, several parts of northeast India are also showing signs of change in LULC pattern leading to forest loss. This study focusses on the expansion of monoculture rubber plantation ( Hevea brasiliensis ) in selected sub-watersheds in north-east India, and distributed in parts of north Tripura, Mizoram and a major portion in the Karimganj district of Assam. Remote sensing and GIS technique has been used to map and analyse the extent of rubber plantation using temporal IRS LISS III satellite data from 1997 to 2013. It has been observed that rubber plantation increased from 4.47 sq. km to 28.42 sq. km in various parts of the study area. The expansion was more rapid during recent times, i.e. during 2010 to 2013. The plantation took place in dense forest, open forest and degraded forest areas. The spread of the plantation was also observed in one reserved forest located within the study area. There are several instances of negative impacts of rubber plantation expansion in Southeast Asia. Similar expansion of rubber plantation has been observed in northeast India as well. Further spread of rubber plantations in the region needs to be regulated to avoid conversion of dense and reserved forest areas by fostering use of mixed cropping methods instead of rubber monocultures, and by adopting more sustainable land use and management practices.

Monitoring rubber plantation expansion using Landsat data time series and a Shapelet-based approach

The expansion of tree plantations in tropical forests for commercial rubber cultivation threatens biodiversity which may affect ecosystem services, and hinders ecosystem productivity, causing net carbon emission. Numerous studies refer to the challenge of reliably distinguishing rubber plantations from natural forest, using satellite data, due to their similar spectral signatures, even when phenology is incorporated into an analysis. This study presents a novel approach for monitoring the establishment and expansion of rubber plantations in Seima Protection Forest (SPF), Cambodia (1995–2015), by detecting and analyzing the ‘shapelet’ structure in a Landsat-NDVI time series. This paper introduces a new classification procedure consisting of two steps: (1) an exhaustive-searching algorithm to detect shapelets that represent a period for relatively low NDVI values within an image time series; and (2) a t-test used to determine if NDVI values of detected shapelets are significantly different than their non-shapelet trend, thereby indicating the presence of rubber plantations. Using this approach, historical rubber plantation events were mapped over the twenty-year timespan. The shapelet algorithm produced two types of information: (1) year of rubber plantation establishment; and (2) pre-conversion land-cover type (i.e., agriculture, or natural forest). The overall accuracy of the rubber plantation map for the year of 2015 was 89%. The multi-temporal map products reveal that more than half of the rubber planting activity (57%) took place in 2010 and 2011, following the granting of numerous rubber concessions two years prior. Seventy-three percent of the rubber plantations were converted from natural forest and twenty-three percent were established on non-forest land-cover. The shapelet approach developed here can be used reliably to improve our understanding of the expansion of rubber production beyond Seima Protection Forest of Cambodia, and likely elsewhere in the tropics.

Comparison of Pixel- and Object-Based Approaches in Phenology-Based Rubber Plantation Mapping in Fragmented Landscapes

The increasing expansion of rubber plantations throughout East and Southeast Asia urgently requires improved methods for effective mapping and monitoring. The phenological information from rubber plantations was found effective in rubber mapping. Previous studies have mostly applied rule-pixel-based phenology approaches for rubber plantations mapping, which might result in broken patches in fragmented landscapes. This study introduces a new paradigm by combining phenology information with object-based classification to map fragmented patches of rubber plantations in Xishuangbanna. This research first delineated the time windows of the defoliation and foliation phases of rubber plantations by acquiring the temporal profile and phenological features of rubber plantations and natural forests through the Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) data. To investigate the ability of finer resolution images at capturing the temporal profile or phenological information, 30 m resolution Landsat image data were used to capture the temporal profile, and a phenology algorithm to separate rubber plantations and natural forests was then defined. The derived phenology algorithm was used by both the object-based and pixel-based classification to investigate whether the object-based approach could improve the mapping accuracy. Whether adding the phenology information to the object-based classification could improve rubber plantation mapping accuracy in mountainous Xishuangbanna was also investigated. This resulted in three approaches: rule-pixel-based phenology, rule-object-based phenology, and nearest-neighbor-object-based phenology. The results showed that the rule-object-based phenology approaches (with overall accuracy 77.5% and Kappa Coefficients of 0.66) and nearest-neighbor-object-based phenology approach (91.0% and 0.86) achieved a higher accuracy than that of the rule-pixel-based phenology approach (72.7% and 0.59). The results proved that (1) object-based approaches could improve the accuracy of rubber plantation mapping compared to the pixel-based approach and (2) incorporating the phenological information from vegetation improved the overall accuracy of the thematic map.

The water-land-food nexus of natural rubber production

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.

Rubber tree allometry, biomass partitioning and carbon stocks in mountainous landscapes of sub-tropical China

Expansion of rubber plantations into sub-optimal environments has been a dominating land conversion in continental South-East Asia in the last decade. Regional evaluation of the carbon sequestration potential of rubber trees depends largely on the selection of suitable allometric equations and the biomass-to-carbon conversion factor. Most equations are age-, elevation-, or clone-specific, and their application therefore gives uncertain results at the landscape level with varying age groups, elevation ranges, and clone types. Currently, for rubber-based systems, none of the allometric equations takes environmental factors (e.g. climate, topographic condition, soil properties, and management scheme) into consideration to allow pan-tropical usage. Against this background, 30 rubber trees with a root profile of up to 2m were destructively harvested and 882 rubber trees were measured non-destructively in 27 plots, covering rotation lengths of 4–35years, elevation gradients of 621–1127m, and locally used clone types (GT1, PRIM600, Yunyan77-4) in mountainous South Western China. Allometric equations for aboveground biomass (AGB) estimations considering diameter at breast height (DBH), tree height (H), and wood density were superior to other equations. A simpler model with similar performance (AGB=0.0419DBH2.316H0.478) can be used if tree-specific wood density is not available. For belowground biomass (BGB) a model using only DBH can provide a robust prediction (BGB=0.207DBH1.668). We also tested goodness of fit for the recently proposed pan-tropical forest model, which includes a bioclimatic factor E, combining indices of temperature and precipitation variability and drought intensity. Prediction of AGB by the model calibrated with the harvested rubber tree biomass and wood density was more accurate than the results produced by the pan-tropical forest model adjusted to local conditions. The relationships between DBH and height and between DBH and biomass were influenced by tapping, therefore biomass and C stock calculations for rubber have to be done using species-specific allometric equations. Based on the analysis of environmental factors acting at the landscape level, we found that above- and belowground carbon stocks were mostly affected by stand age, soil clay content, aspect, and planting density. Increasing planting density to >570 trees per ha according to the regional plantation management strategy had a negative impact on aboveground carbon stock of old rubber plantations. The integration of bioclimatic and regional management factors is a further approach to build widely applicable biomass models for pan-tropical rubber-based systems. The results of this study provide reference for reliable carbon accounting in other rubber-cultivated regions.

Risk of exposure to potential vector mosquitoes for rural workers in Northern Lao PDR.

BackgroundOne major consequence of economic development in South-East Asia has been a rapid expansion of rubber plantations, in which outbreaks of dengue and malaria have occurred. Here we explored the difference in risk of exposure to potential dengue, Japanese encephalitis (JE), and malaria vectors between rubber workers and those engaged in traditional forest activities in northern Laos PDR.Methodology/Principal findingsAdult mosquitoes were collected for nine months in secondary forests, mature and immature rubber plantations, and villages. Human behavior data were collected using rapid participatory rural appraisals and surveys. Exposure risk was assessed by combining vector and human behavior and calculating the basic reproduction number (R0) in different typologies. Compared to those that stayed in the village, the risk of dengue vector exposure was higher for those that visited the secondary forests during the day (odds ratio (OR) 36.0), for those living and working in rubber plantations (OR 16.2) and for those that tapped rubber (OR 3.2). Exposure to JE vectors was also higher in the forest (OR 1.4) and, similar when working (OR 1.0) and living in the plantations (OR 0.8). Exposure to malaria vectors was greater in the forest (OR 1.3), similar when working in the plantations (OR 0.9) and lower when living in the plantations (OR 0.6). R0 for dengue was >2.8 for all habitats surveyed, except villages where R0≤0.06. The main malaria vector in all habitats was Anopheles maculatus s.l. in the rainy season and An. minimus s.l. in the dry season.Conclusions/SignificanceThe highest risk of exposure to vector mosquitoes occurred when people visit natural forests. However, since rubber workers spend long periods in the rubber plantations, their risk of exposure is increased greatly compared to those who temporarily enter natural forests or remain in the village. This study highlights the necessity of broadening mosquito control to include rubber plantations.

Extracting distribution and expansion of rubber plantations from Landsat imagery using the C5.0 decision tree method

Natural tropical rainforests in China’s Xishuangbanna region have undergone dramatic conversion to rubber plantations in recent decades, resulting in altering the region’s environment and ecological systems. Therefore, it is of great importance for local environmental and ecological protection agencies to research the distribution and expansion of rubber plantations. The objective of this paper is to monitor dynamic changes of rubber plantations in China’s Xishuangbanna region based on multitemporal Landsat images (acquired in 1989, 2000, and 2013) using a C5.0-based decision-tree method. A practical and semiautomatic data processing procedure for mapping rubber plantations was proposed. Especially, haze removal and deshadowing were proposed to perform atmospheric and topographic correction and reduce the effects of haze, shadow, and terrain. Our results showed that the atmospheric and topographic correction could improve the extraction accuracy of rubber plantations, especially in mountainous areas. The overall classification accuracies were 84.2%, 83.9%, and 86.5% for the Landsat images acquired in 1989, 2000, and 2013, respectively. This study also found that the Landsat-8 images could provide significant improvement in the ability to identify rubber plantations. The extracted maps showed the selected study area underwent rapid conversion of natural and seminatural forest to a rubber plantations from 1989 to 2013. The rubber plantation area increased from 2.8% in 1989 to 17.8% in 2013, while the forest/woodland area decreased from 75.6% in 1989 to 44.8% in 2013. The proposed data processing procedure is a promising approach to mapping the spatial distribution and temporal dynamics of rubber plantations on a regional scale.

Adoption of intercropping among smallholder rubber farmers in Xishuangbanna, China

ABSTRACTWhile the expansion of rubber plantations in the mountainous areas of Southern China has contributed to poverty reduction among the indigenous ethnic groups, the concerns about the associated negatives on ecosystems and sustainable development of livelihoods is rising. One of the measures suggested to reduce environmental and economic risks is rubber intercropping. This study uses cross-section data of some 600 rubber farmers in Xishuangbanna, as a basis to develop four empirical models in order to analyse adoption of intercropping at farm and at plot level. Our study shows that only a small proportion of rubber farmers have adopted intercropping, with tea being the most frequently adopted intercrop. However, we also find that intercropping is an important source of income for the household in the lower income category. Intercropping adoption is affected by ethnicity, household wealth and family labour. The choice of intercrops depends on the nature of rubber plots, the age of rubber trees and geography. This study contributes to a better understanding of the transformation path from rubber monoculture to more diversified, rubber-based agroforestry systems and thus can provide important information for agricultural extension services charged with the promotion of sustainable rubber-based livelihood systems in the Mekong area.

Rubber Plantation Expansion Related Land Use Change along the Laos-China Border Region

Spatial-temporal changes of land use and land cover in Luang Namtha Province in northern part of Laos was analyzed using Landsat TM (Thematic Mapper)/ETM+ (Enhanced Thematic Mapper) images from 1990 to 2010 since the opening of the Boten border adjacent to China. The results showed that: (1) “forest land—cultivated land—grassland” was the primary landscape structure. Woodland was the major land cover type, while paddy field was the dominant land use type replaced by rubber plantation in 2010; (2) since the opening of the border crossings in 1994, the rate and intensity of land use change were accelerated and enhanced gradually, especially in the recent decade. Woodland decreased significantly, while shrubland, rubber plantation and swidden land increased obviously. Rubber plantation and swidden land showed the fastest growth derived from woodland and shrubland, indicating continuous human activities and slash-and-burn farming; and (3) during 1990–2010, swidden land was mainly located in northern mountainous areas with frequently increased changing spatial distribution in the recent decade. Rubber plantation was mainly distributed in the border region of China and Laos with the expansion from the border region into the non-frontier of Laos with Luang Namtha City as the center. Woodland reduction was so obvious along the Kunming-Bangkok highway.

Forestland-cover changes in China’s tropical area: Historical patterns, implications, and policy options—a case study from Xishuangbanna

ABSTRACTTo effectively conserve tropical forested areas, it is useful to study and understand historical land-cover changes and local people’s attitudes toward the current land-uses. Using forest inventory data, and data collected from a survey of 145 households, we explored the forestland-cover changes, within the past 50 yr, in Xishuangbanna, China, and assessed the local residents’ perceptions toward the existing forestland management schemes. Our analysis showed that although forestland coverage has increased during the time-period studied, the increase can be mostly attributed to the expansion of rubber plantations. Forest degradation continues to be an issue in the area studied. The government’s attempts to mitigate the effects of rubber monocultures, by promoting environment-friendly plantations, have been proven challenging, which was mainly due to locals’ unfavorable view of the plan. Also, because of the recent decreasing prices of dry rubber, many locals have lost their interest in managing the forest plots they own, hindering further the successful implementation of the plan. Considering these challenges, and the strong negative effects of rubber monocultures on biodiversity, we argue that the current incentives should be further strengthened to promote more efficiently the government’s “Environment-Friendly Ecological Rubber Plantations” plan, and the joint management of the locals’ forest plots.