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1.
China’s Primary Programs of Terrestrial Ecosystem Restoration: Initiation, Implementation, and Challenges 总被引:5,自引:0,他引:5
China has undertaken several major programs of terrestrial ecosystem restoration (ERPs) in recent years, including the Natural
Forest Protection Program (NFPP) and the Sloping Land Conversion Program (SLCP). There have been reports on the implementation
of these programs, their preliminary impacts, and the problems encountered in carrying them out; a great deal has been learned
from these studies. Nonetheless, China’s ERPs are not limited to the NFPP and the SLCP. Because a complete documentation and
a timely update of these major efforts are still missing from the literature, it is difficult to gauge the scope of these
programs and the scale of their impacts. In addition, a more thorough and critical analysis of both the general ERP policy
and the specific technical measures used in implementing the ERPs remains urgently needed. The purpose of this article is
to tackle these tasks. Overall, with the huge government investments in the ERPs, tremendous progress has been made in implementing
them. To complete them successfully and to fundamentally improve the targeted ecosystems, however, it is essential for China
to have a more balanced and comprehensive approach to ecological restoration. This approach must include: adopting better
planning and management practices; strengthening the governance of program implementation; emphasizing the active engagement
of local people; establishing an independent, competent monitoring network; and conducting adequate assessments of program
effectiveness and impact. 相似文献
2.
Nonpoint Source Pollution Responses Simulation for Conversion Cropland to Forest in Mountains by SWAT in China 总被引:1,自引:0,他引:1
Several environmental protection policies have been implemented to prevent soil erosion and nonpoint source (NPS) pollutions
in China. After severe Yangtze River floods, the “conversion cropland to forest policy” (CCFP) was carried out throughout
China, especially in the middle and upper reaches of Yangtze River. The research area of the current study is located in Bazhong
City, Sichuan Province in Yangtze River watershed, where soil erosion and NPS pollution are serious concerns. Major NPS pollutants
include nitrogen (N) and phosphorus (P). The objective of this study is to evaluate the long-term impact of implementation
of the CCFP on stream flow, sediment yields, and the main NPS pollutant loading at watershed level. The Soil and Water Assessment
Tool (SWAT) is a watershed environmental model and is applied here to simulate and quantify the impacts. Four scenarios are
constructed representing different patterns of conversion from cropland to forest under various conditions set by the CCFP.
Scenario A represented the baseline, i.e., the cropland and forest area conditions before the implementation of CCFP. Scenario
B represents the condition under which all hillside cropland with slope larger than 25° was converted into forest. In scenario
C and D, hillside cropland with slope larger than 15° and 7.5° was substituted by forest, respectively. Under the various
scenarios, the NPS pollution reduction due to CCFP implementation from 1996–2005 is estimated by SWAT. The results are presented
as percentage change of water flow, sediment, organic N, and organic P at watershed level. Furthermore, a regression analysis
is conducted between forest area ratio and ten years’ average NPS load estimations, which confirmed the benefits of implementing
CCFP in reducing nonpoint source pollution by increasing forest area in mountainous areas. The reduction of organic N and
organic P is significant (decrease 42.1% and 62.7%, respectively) at watershed level. In addition, this study also proves
that SWAT modeling approach can be used to estimate NPS pollutants’ impacts of land use conversions in large watershed. 相似文献
3.
Yuandong Zhang Shirong Liu Xiaohua Wei Jingtao Liu Guobin Zhang 《Journal of the American Water Resources Association》2008,44(5):1144-1153
Abstract: To combat its growing ecological problems, China has implemented a large‐scale Natural Forest Protection Program (NFPP). Under the umbrella of this program, the Sloping Land Conversion Program (SLCP) was established in 1999 to return cultivated land with slopes of 25° or more to perennial vegetation. However, the regional impacts on water resource management that are incurred by afforestation have not been carefully evaluated, especially in the subalpine region of southwestern China. The purpose of the present study was to provide reference values for the SLCP by evaluating the potential impact of afforestation on water yield under different climatic regimes. Accordingly, evapotranspiration (ET) in cropland (CL), shrubland, and general forest was calculated using a modification of Thornthwaite’s method, and in coniferous forest, broad‐leaved forest (BF), and mixed coniferous and broad‐leaved forest (MF) using the Surface Energy Balance Algorithm for Land (SEBAL) model. The results of both approaches showed that afforestation reduces water yield by 9.6‐24.3% depending on the types of conversion and climatic conditions. Water‐yield reduction is greatest (>143.4 mm, or 24.3%) when CL is converted to BF in dry climate conditions. Compared with the other forest types studied, coniferous plantations prevented water‐yield reduction by as much as 9.6% because of their relatively low levels of ET. It is expected that implementation of the SLCP, together with continuing climate change, will further pressure regional water resources. Thus, the effectiveness of afforestation must be evaluated in a broader context while taking into account its positive ecological aspects, such as soil‐erosion control, the preservation of biodiversity, and the significant carbon sequestration provided by forests. 相似文献
4.
This study aimed to analyze the ecological, socio-economic and policy implications of land-use diversity in a traditional
village landscape (900–1,000 m amsl.) in the Garhwal region of Indian Himalaya. The village landscape was differentiated into three major land-use types viz.,
forests, settled agriculture and shifting agriculture. Settled agriculture was further differentiated into four agroecosystem
types viz., homegarden system (HGS), rainfed agroforestry system (RAS), rainfed crop system (RCS) and irrigated crop system
(ICS), and shifting agriculture system (SAS) was differentiated into different stages of a 4-year long cropping phase and
a 7-year long fallow phase, and forests into Community Forests (CF) and Reserve Forests (RF). HGS is the most productive agroecosystem,
with soil organic carbon and nutrient concentrations significantly higher than all other forest/agricultural land-uses. Farmers
capitalize upon crop diversity to cope with the risks and uncertainties of a monsoon climate and spatial variability in ecological
factors influencing productivity. The SAS, a land-use adopted as a means of acquiring inheritable rights over larger land
holdings provided in the policies during the 1890s, is less efficient in terms of land productivity than the traditional RAS
and HGS but is maintained for its high labour productivity coupled with availability of high-quality fuelwood from fallow
vegetation. Dominance of fodder trees in the RAS seems to derive from policies causing shortage of fodder available from forests.
Cultural norms have favoured equity by allowing hiring of labour only from within the village community and income from non-timber
forest products only to the weaker section of the society. Conversion of rainfed to irrigated cropping, a change facilitated
by the government, improves agricultural productivity but also increases pressure on forests due to higher rates of farmyard
manure input to the irrigated crops. Existing forest management systems are not effective in maintenance of a large basal
area in forests together with high levels of species richness, soil fertility and resistance to invasive alien species Lantana camara. Farmers have to spend huge amount of labour and time in producing manure, managing livestock and other subsidiary farm activities.
Interlinkages among agriculture, forests and rural economy suggest a need of replacing the present policies of treating agricultural
development, forest conservation and economic development as independent sectors by an integrated sustainable development
policy. The policy should promote technological and institutional innovations enabling parallel improvements in agricultural
productivity and functions of forest ecosystems. 相似文献
5.
The Spatio-Temporal Dynamic Pattern of Rural Residential Land in China in the 1990s Using Landsat TM Images and GIS 总被引:2,自引:0,他引:2
Through interpreting Landsat TM images, this study analyzes the spatial distribution of rural settlements in China in 2000.
It calculates rural residential land percentage for every 1-km2 cell. The entire country is divided into 33 regions to investigate the spatio-temporal dynamic patterns of rural residential
land during the 1990s. According to the remote sensing survey, the rural residential land increased by 7.88 × 105 ha in the 1990s. The increment of rural residential land was 0.55 million ha in 1990–1995 and 0.23 million ha in 1995–2000.
In 1990–1995, rural residential land increased dramatically in the eastern regions such as the Yangtze River Delta, Pearl
River Delta, and North China Plain, accounting for 80.80% of the national growth; the expansion in the western regions was
much more moderate. In 1995–2000, the expansion of rural residential land in eastern regions slowed, accounting for only 58.54%
of the increase at the national level, whereas the expansion in the western regions accelerated. Rapid rural residential development
resulted from increasing home construction and the limited control on rural land. The great regional disparity reflected the
regional economic development and land-use policy change. Our finding shows that nearly 60% of the rural residential area
came from cropland. 相似文献
6.
Erik J. van Waveren 《Natural resources forum》2007,31(3):188-197
This paper examines the effects of growing land pressure on the distribution and quality of cropland allocations on customary tenured land (CTL) in Swaziland. Within the wider Sub‐Saharan context, the reform of indigenous tenure systems is now generally seen as a process of adaptation rather than replacement. The legal recognition of (existing and future) user rights is considered a practical way forward. This essentially rights‐based approach may divert attention from technical inadequacies indigenous systems may have, particularly under conditions of increasing land pressure. The case of CTL substantiates such shortcomings. CTL has seen a marked growth in population and land allocations since Independence. This had led to concerns on the land distribution efficiency in view of the improved agricultural production required to sustain the increasing number of rural households. By analysing historical changes in the number, size and quality of cropland allocations in selected rural communities, this paper demonstrates the occurrence of a high degree of inconsistency in cropland distribution at the community level, as well as inefficient land distribution at higher levels of scale. These shortcomings threaten the sustainability of the local agricultural production systems, and will need to be addressed in any meaningful reform process. 相似文献
7.
Environmental conditions significantly affect production, but are often ignored in studies analysing productivity and efficiency leading to biased results. In this study, we examine the influence of selected environmental factors on productivity and efficiency in wheat farming in Bangladesh. Results reveal that environmental production conditions significantly affect the parameters of the production function and technical efficiency, as well as correlates of inefficiency. Controlling for environmental production conditions improves technical efficiency by 4 points (p<0.01) from 86% to 90%. Large farms are more efficient relative to small and medium sized farms (p<0.01 and 0.05), with no variation among regions. Policy implications include soil fertility improvement through soil conservation and crop rotation, improvement in managerial practices through extension services and adoption of modern technologies, promotion of education, strengthening the research-extension link, and development of new varieties that have higher yield potential and are also suitable for marginal areas. 相似文献
8.
从提高城市建设用地配置效率角度出发,运用DEA-Malmquist指数模型,通过选择投入产出要素对辽宁省2006-2012年城市建设用地全要素生产率进行分析,对全省及各市城市建设用地配置效率的变化和技术效率、技术进步对城市建设用地配置效率的影响做出评价.研究表明,研究期内各城市全要素生产率处于小幅增长态势,平均增长率为1.1%,纯技术效率呈波动性增减,表明各城市尚未充分利用先进技术和资源优化配置,规模效率普遍偏低,平均值为0.996<1,未向最优规模靠近,技术进步对全要素生产率变化指数的增长贡献率不高. 相似文献
9.
Ivan D. Trofimov 《Natural resources forum》2024,48(1):232-256
The environmental Kuznets curve (EKC) hypothesis assumes the nonlinear relationship between production and its environmental effects, suggesting that the negative effect of production on the natural environment is reversed at higher levels of development. In contrast to the majority of the studies, this paper considers the possibility of non-linear effects of per capita output on agricultural land use (cropland), as one of the natural resource stocks, and additionally examines the influence of demographic and productivity variables on the agricultural land use. The study draws on panel data from 143 economies over the 1990–2019 period and employs a series of panel econometrics techniques (including panel unit root and cointegration tests, panel ordinary least squares, generalized method of moments, and panel quantile models). The results unequivocally indicate the inverted U-shaped relationship between the GDP per capita and cropland use, as per EKC hypothesis. The results are robust with respect to employing different techniques, the identified turning points correspond to low and low-middle-income levels, and the effects of agricultural productivity and population density on land use are respectively negative and positive. 相似文献
10.
Assessing farm-level agricultural sustainability over a 60-year period in rural eastern India 总被引:1,自引:1,他引:0
Agricultural sustainability is a vital parameter to be ascertained locally and globally if food security is to be achieved
and maintained. Agricultural sustainability is the combined product of social, economic and ecological sustainability. It
is also a function of temporal and spatial variations, a fact which indicates that area-specific sustainability indices need
to be designed. We present here an Agricultural Sustainability Index (ASI) for rural eastern India and use it to calculate
the ASI for 150 farms for three decades over a 60-year period, viz., 1950–1960, 1980–1990 and 2000–2010 for a representative
Indian village of Gangapur (25°83′N, 85°65′E). The ASI was calculated using 30 variables, 10 each of social, economic and
ecological sustainability. An extensive questionnaire-based survey was carried out to collect the relevant data. Our study
reveals that over a 60-year period, ASI values do not show a statistically significant change. We conclude that the agricultural
practices of the region have maintained sustainability so far although the scope for improvement in several broad areas identified
by us is immense. Increased ecological literacy and better implementation of government policies, aiming at health, education
and better scientist–farmer interactions, must target improved ASI values in coming decades. 相似文献
11.
Construction of six large dams and reservoirs on the Missouri River over the last 50–75 years has resulted in major landscape
changes and alterations in flow patterns, with implications for riparian forests dominated by plains cottonwood (Populus deltoides). We quantified changes in land cover from 1892–1950s and the 1950s–2006 and the current extent and age structure of cottonwood
forests on seven segments (two reservoir and five remnant floodplain) comprising 1127 km (53 %) of the unchannelized upper
two-thirds of the Missouri River. Riparian forest area declined by 49 %; grassland 61 %; shrubland 52 %; and sandbar habitat
96 %; while agricultural cropland increased six-fold and river/reservoir surface area doubled from 1892 to 2006. Net rates
of erosion and accretion declined between the 1892–1950s and 1950s–2006 periods. Accretion exceeded erosion on remnant floodplain
segments, resulting in declines in active channel width, particularly in 1950s–2006. Across all study segments in 2006, most
cottonwood stands (67 %) were >50 years old, 22 % were 25–50 years old, and only 10 % were <25 years old. Among stands <50 years
old, the higher proportion of 25–50 year old stands represents recruitment that accompanied initial post-dam channel narrowing;
while declines in sandbar and shrubland area and the low proportion of stands <25 years old suggest declines in geomorphic
dynamism and limited recruitment under recent river management. Future conservation and restoration efforts should focus both
on limiting further loss of remnant cottonwood stands and developing approaches to restore river dynamics and cottonwood recruitment
processes. 相似文献
12.
中国工业废水治理效率评价 总被引:1,自引:0,他引:1
基于投入产出的思想,应用DEA模型对2008年中国工业废水治理效率进行静态评价,得出各地区当前工业废水治理效率.用Malmquist指数对中国2003-2008年工业废水治理效率进行动态评价,分别得出近几年中国工业废水治理的名义全要素生产率和实际全要素生产率.结果表明,中国工业废水平均治理效率仅为0.630,2008年达到DEA有效的地区仅占16.7%,几乎所有地区都处在规模收益递减;2003-2008年间的中国工业废水治理名义T下P为0.922,实际TFP为0.943,即分别在此期间平均每年下降7.8%和5.7%,造成逐年下降的主要原因是技术的落后. 相似文献
13.
With 207 million ha of forest covering 22% of its land area, China ranks fifth in the world in forest area. Rapid economic
growth, climate change, and forest disturbances pose new, complex challenges for forest research and management. Progress
in meeting these challenges is relevant beyond China, because China’s forests represent 34% of Asia’s forests and 5% of the
worlds’ forests. To provide a broader understanding of these management challenges and of research and policies that address
them, we organized this special issue on contemporary forest research and management issues in China. At the national level,
papers review major forest types and the evolution of sustainable forestry, the development of China’s forest-certification
efforts, the establishment of a forest inventory system, and achievements and challenges in insect pest control in China.
Papers focused on Northern China address historical, social, and political factors that have shaped the region’s forests;
the use of forest landscape models to assess how forest management can achieve multiple objectives; and analysis and modeling
of fuels and fire behavior. Papers addressing Central and South China describe the “Grain for Green” program, which converts
low productivity cropland to grassland and woodland to address erosion and soil carbon sequestration; the potential effects
of climate change on CO2 efflux and soil respiration; and relationships between climate and net primary productivity. China shares many forest management
and research issues with other countries, but in other cases China’s capacity to respond to forest management challenges is
unique and bears watching by the rest of the world. 相似文献
14.
Assessing Sediment Yield for Selected Watersheds in the Laurentian Great Lakes Basin Under Future Agricultural Scenarios 总被引:1,自引:1,他引:0
Yang Shao Ross S. Lunetta Alexander J. Macpherson Junyan Luo Guo Chen 《Environmental management》2013,51(1):59-69
In the Laurentian Great Lakes Basin (GLB), corn acreage has been expanding since 2005 in response to high demand for corn as an ethanol feedstock. This study integrated remote sensing-derived products and the Soil and Water Assessment Tool (SWAT) within a geographic information system (GIS) modeling environment to assess the impacts of cropland change on sediment yield within four selected watersheds in the GLB. The SWAT models were calibrated during a 6 year period (2000–2005), and predicted stream flows were validated. The R 2 values were 0.76, 0.80, 0.72, and 0.81 for the St. Joseph River, the St. Mary River, the Peshtigo River, and the Cattaraugus Creek watersheds, respectively. The corresponding E (Nash and Sutcliffe model efficiency coefficient) values ranged from 0.24 to 0.79. The average annual sediment yields (tons/ha/year) ranged from 0.12 to 4.44 for the baseline (2000 to 2008) condition. Sediment yields were predicted to increase for possible future cropland change scenarios. The first scenario was to convert all “other” agricultural row crop types (i.e., sorghum) to corn fields and switch the current/baseline crop rotation into continuous corn. The average annual sediment yields increased 7–42 % for different watersheds. The second scenario was to further expand the corn planting to hay/pasture fields. The average annual sediment yields increased 33–127 % compared with baseline conditions. 相似文献
15.
The agricultural and industrial development of small cities is the primary environmental management strategy employed to make full use of extra labor in the rural areas of China. The ecological and economic consequences of this development strategy will affect over 100 million people and change the organization of the Chinese landscape. In this study, we examined the agricultural development of Shunde, a small city in Guangdong Province, over the period 1978 until 2000. Our analysis of the ecological and economic dynamics of the agricultural system revealed the dominant role of labor in the intensification of agricultural production, even though the use of fuels, fertilizers and machines also increased during this time. The Shunde agricultural system was examined from both biophysical or donor-based and human utility or receiver-based perspectives, using emergy and economic methods, respectively. After 22 years of urbanization, the Shunde agricultural system was still able to fill 96% of the local demand for agricultural products using only 6% of its total yield compared to using 14% of the total yield in 1978. Aquaculture developed quickly during the study period as grain production decreased. In 2000, the production of fish, pork, and vegetables accounted for 92% of the total emergy output of the system; however, the emergy buying power of the money received in exchange was lower than the emergy contained in the products exported. The excess emergy exported is the basis for a high quality diet delivered to city dwellers at a relatively low price. In the 1980s, the productivity of both land and labor increased; but after 1992 the productivity of labor decreased, causing the efficiency of the whole agricultural system to decrease. We recommend that processing plants be established for the main agricultural products of Shunde to decrease the emergy loss in trading and to increase employment. The effect of including monetized ecosystem services in the balance between the emergy delivered to the markets in agricultural products and the emergy buying power of the money received was to decrease the emergy gained by the Shunde agricultural system. 相似文献
16.
Honghai Qi Mustafa S. Altinakar Dalmo A.N. Vieira Bahram Alidaee 《Journal of the American Water Resources Association》2008,44(4):866-878
Abstract: A principal contributor to soil erosion and nonpoint source pollution, agricultural activities have a major influence on the environmental quality of a watershed. Impact of agricultural activities on the quality of water resources can be minimized by implementing suitable agriculture land‐use types. Currently, land uses are designed (location, type, and operational schedule) based on field study results, and do not involve a science‐based approach to ensure their efficiency under particular regional, climatic, geological, and economical conditions. At present, there is a real need for new methodologies that can optimize the selection, design, and operation of agricultural land uses at the watershed scale by taking into account environmental, technical, and economical considerations, based on realistic simulations of watershed response. In this respect, the present study proposes a new approach, which integrates computational modeling of watershed processes, fluvial processes in the drainage network, and modern heuristic optimization techniques to design cost effective land‐use plans. The watershed model AnnAGNPS and the channel network model CCHE1D are linked together to simulate the sediment and pollutant transport processes. Based on the computational results, a multi‐objective function is set up to minimize soil losses, nutrient yields, and total associated costs, while the production profits from agriculture are maximized. The selected iterative optimization algorithm uses adaptive Tabu Search heuristic to flip (switching from one alternative to another) land‐change variables. USDA’s Goodwin Creek experimental watershed, located in Northern Mississippi, is used to demonstrate the capabilities of the proposed approach. The results show that the optimized land‐use design with BMPs using an integrated approach at the watershed level can provide efficient and cost‐effective conservation of the environmental quality by taking into account both productivity and profitability. 相似文献
17.
Environmental performance and spillover effects on productivity: evidence from horticultural firms 总被引:3,自引:3,他引:0
Galdeano-Gómez E Céspedes-Lorente J Martínez-Del-Río J 《Journal of environmental management》2008,88(4):1552-1561
This study investigates the effect of environmental investment and related spillover effects on productivity in the agricultural sector by using a panel data of horticultural firms in Andalusia (Southern Spain). The results indicate a positive relationship between firm investment in environmental practices and productivity improvement, also showing the presence of positive environmental spillovers. In a second-stage of analysis, the incidence of environmental factors in firm specific individual technical efficiency is estimated. This analysis also shows the link between environmental knowledge diffusion and horticultural firms' performance. 相似文献
18.
考虑“水—土—能—碳”关联,本文将水土资源要素纳入投入变量,构建了我国工农业碳排放效率投入产出测度指标,运用考虑非期望产出的SBM-undesirable模型计算我国29个省份2004—2017年农业、工业部门碳排放效率,利用乘法逆转法计算碳减排潜力并对影响碳排放的投入产出因素进行分析。结果表明:研究期内我国整体农业、工业碳排放效率均呈波动下降趋势,各年的农业碳排放效率均高于工业碳排放效率,江苏、山东等7省份农业碳排放效率以及北京、天津工业碳排放效率最优;各省份农业、工业减排潜力和规模具有显著差异,山西、甘肃的农业、工业碳减排均具有较大潜力;我国绝大多数省份均存在农业、工业的资源能源投入冗余和非期望产出冗余,土地资源投入过剩是影响农业碳排放效率的最重要因素,水资源投入过剩是影响工业碳排放效率的最重要因素。碳排放效率较低省份应积极开展技术创新,发展低碳技术,提高水土资源和能源利用效率,减少碳排放。 相似文献
19.
Efrem Garedew Mats Sandewall Ulf Söderberg Bruce M. Campbell 《Environmental management》2009,44(4):683-694
Understanding the complexity of land-use and land-cover (LULC) changes and their driving forces and impacts on human and environmental
security is important for the planning of natural resource management and associated decision making. This study combines
and compares participatory field point sampling (pfps) and remote sensing to explore local LULC dynamics. The study was conducted
in two peasant associations located in the central Ethiopian Rift Valley, which is a dry-land mixed farming area exposed to
rapid deforestation. From 1973–2006, the area of cropland doubled at the expense of woodland and wooded-grassland in both
of the study sites. Major deforestation and forest degradation took place from 1973–1986; woodland cover declined from 40%
to 9% in one of the study sites, while the other lost all of its original 54% woodland cover. Our study concludes that assessing
LULC dynamics using a combination of remote sensing and pfps is a valuable approach. The two methods revealed similar LULC
trends, while the pfps provided additional details on how farmers view the changes. This study documents dramatic trends in
LULC over time, associated with rapid population growth, recurrent drought, rainfall variability and declining crop productivity.
The alarming nature of these trends is reflected in a decrease in the livelihood security of local communities and in environmental
degradation. Given these dry-land conditions, there are few opportunities to improve livelihoods and environmental security
without external support. If negative changes are to be halted, action must be taken, including building asset bases, instituting
family planning services, and creating opportunities outside these marginal environments. 相似文献
20.
Rajiv K. Sinha 《Journal of Agricultural and Environmental Ethics》1997,10(2):183-197
The Green Revolution in India which was heralded in the 1960‘s was a mixed blessing. Ambitious use of agro-chemicals boosted
food production but also destroyed the agricultural ecosystem. Of late Indian farmers and agricultural scientists have realized
this and are anxious to find alternatives – perhaps a non-chemical agriculture – and have even revived their age-old traditional
techniques of natural farming. Scientists are working to find economically cheaper and ecologically safer alternatives to
agro-chemicals. Blue-Green Algae Biofertilizers, Earthworm Vermicomposts (Vermiculture), biological control of pests and herbal
biopesticides are showing promise. Saline agriculture and sewage farming are also being promoted in India to augment food
production in the face of water scarcity. There is a move to search for alternative foods, which are more nutritious, cheaper
and have shorter harvest cycles. Farm and food policy in India has to change its outlook before there can be a second green
revolution.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献