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1.
We examine dramatic cropland expansion in Karamoja, Uganda by investigating the links between biophysical and political historical events leading to the current state of agricultural land use. Our objective was to quantify agricultural expansion, uncover the dominant drivers leading to the current state of agricultural land use and its impacts on livelihoods. Region wide analysis of remotely sensed data, land use policy and history as well as farmer interviews were undertaken. We posit that government programs instituting sedentary agriculture are the most significant drivers of cropland expansion in Karamoja. We show a 299% increase in cropland area between 2000 and 2011 with most expansion occurring in Moroto District (from 706 ha to 23,328 ha). We found no evidence of an increase in overall crop production or food security and food aid continues to be essential due to recurrent crop failures. Due to lack of resources for inputs (e.g., seeds and labor) cultivated fields remain very small in size and over 55% of once cultivated land is left fallow. Our findings bring into question whether continued promotion of rain-fed agriculture in Karamoja serves the best interests of the people. Current cropland expansion is directly competing and compromising pasture areas critical for livestock-based livelihoods. Without strong agricultural extension programs and major investments in climate-smart options, cropland expansion will continue to have a net negative impact, especially in the context of current climate projections which indicate a future decrease in rainfall, increase in temperature and an increase in the frequency and magnitude of extreme events.  相似文献   

2.
Increased demand for both agricultural production and forest restoration may lead to increased competition for land in the next decades. Sustainably increasing cattle ranching productivity is a potential solution to reconcile different land uses, while also improving biodiversity conservation and the provision of ecosystem services. If not strategically implemented in integration with complementary policies, sustainable intensification can however result in negative environmental, economic and social effects. We analyzed the potential for sustainable intensification as a solution for a conflict between agricultural expansion and forest restoration in the Paraitinga Watershed at the Brazilian Atlantic Forest, a global biodiversity hotspot. In addition, we provide policy recommendations for sustainable development in the region, based on interviews with producers and local actors. We found that the Paraitinga Watershed has the potential to increase its cattle-ranching productivity and, as a result, relinquish spared land for other uses. This was true even in the most conservative intensification scenario considered (50% of the maximum potential productivity reached), in which 76,702 ha of pastures can be spared for other uses (46% of total pasture area). We found that restoration, apiculture and rural tourism are promising activities to promote sustainable development in the region, thus potentially increasing food production and mitigating competition for land. Our study shows that results from socioeconomic interviews and biophysical modelling of potential productivity increases offer robust insights into practical solutions on how to pursue sustainable development in one of the world’s most threatened biodiversity hotspots.  相似文献   

3.
Fed by demand for beef within Brazil and in global markets, the Brazilian herd grew from 147 million head of cattle in 1990 to ≈200 million in 2007. Eighty-three percent of this expansion occurred in the Amazon and this trend is expected to continue as the industry bounces back from a recent agricultural downturn. Intensification of the cattle industry has been suggested as one way to reduce pressure on forest margins and spare land for soybean or sugarcane production, and is the cornerstone of Brazil's plan for mitigation of greenhouse gas emissions. To this end, federal credit programs and research and development activities in Brazil are aligning to support intensification goals, but there is no guarantee that this push for intensification will decrease the demand for land at the forest margin and as result curb CO2 emissions from deforestation. In this paper we use a spatially explicit rent model which incorporates the local effects of biophysical characteristics, infrastructure, land prices, and distance to markets and slaughterhouses to calculate 30-year Net Present Values (NPVs) of extensive cattle ranching across the Brazilian Amazon. We use the model to ask where extensive ranching is profitable and how land acquisition affects profitability. We estimate that between 17% and 80% of land in the Amazon would have moderate to high NPVs when ranched extensively if it were settled, i.e. if the rancher does not buy the land but acquires it through land grabbing. In addition, we estimate that between 9% and 13% of land in the Amazon is vulnerable to speculation (i.e. areas with positive NPVs only if land is settled and not purchased), which suggests that land speculation is an important driver of extensive ranching profitability, and may continue to be in the future. These results suggest that pro-intensification policies such as credit provision for improved pasture management and investment in more intensive production systems must be accompanied by implementation and enforcement of policies that alter the incentives to clear forest for pasture, discourage land speculation, and increase accountability for land management practices if intensification of the cattle sector is to deter new deforestation and displace production from low-yield, extensive cattle production systems in frontier regions of the Brazilian Amazon.  相似文献   

4.
We model Central American migrant-sending household agricultural practices given labor losses and the concomitant infusion of remittances. Under the new economics of labor migration (NELM) framework, it is hypothesized that smallholder farm households invest remittance income in their land either to increase crop production or to transition to cattle ranching. We test this hypothesis by developing a combination of multivariate logistic, Poisson and beta regression techniques using Latin American Migration Project data to determine how agricultural land use change compared among migrant and non-migrant households in Costa Rica, El Salvador, Guatemala, and Nicaragua. Results indicate that a rise in months spent abroad and remittances returned do not translate into a higher percentage of farm sales, intensification or transition to cattle ranching – counter to NELM. However, farmers are investing remittances to increase row crop and pasture land holdings. These findings suggest remittance investments in quantitative increase rather than qualitative change in land use practices. Given the expansive land demands supporting low intensity smallholder agriculture and cattle, and the land degradation cattle precipitate particularly, the trend does not augur well for the sustainability of rural landscapes increasingly transformed by international remittances. Appropriate policies to champion coupled human-land system sustainability in Central America might usefully consider viable land use alternatives to remittance investments dedicated to crop and pasture expansion.  相似文献   

5.
In this paper we analyze the indirect land use change (ILUC) effects of ethanol production expansion in Brazil through the use of an inter-regional, bottom-up, dynamic general equilibrium model calibrated with the 2005 Brazilian I-O table. A new methodology to deal with ILUC effects is developed, using a transition matrix of land uses calibrated with Agricultural Censuses data. Agriculture and land use are modeled separately in each of 15 Brazilian regions with different agricultural mix. This regional detail captures a good deal of the differences in soil, climate and history that cause particular land to be used for particular purposes.Brazilian land area data distinguish three broad types of agricultural land use, Crop, Pasture, and Plantation Forestry. Between one year and the next the model allows land to move between those categories, or for unused land to convert to one of these three, driven initially by the transition matrix, changing land supply for agriculture between years. The transition matrix shows Markov probabilities that a particular hectare of land used in one year for some use would be in another use next period. These probabilities are modified endogenously in the model according to the average unit rentals of each land type in each region.We ask whether biofuel expansion is consistent with new laws, limiting forest clearing in Brazil. A simulation with ethanol expansion scenario is performed for year 2020, in which land supply is allowed to increase only in states located on the agricultural frontier. Results suggest that each new hectare of sugar cane requires only 0.14 ha of new land, with another 0.47 ha converted from pasture use. Hence policies limiting deforestation are unlikely to prevent greater ethanol production. Finally, regional differences in sugarcane productivity are found to be important elements in ILUC effects of sugar cane expansion.  相似文献   

6.
The bioeconomy is gaining growing attention as a perceived win-win strategy for environment and economy in the EU. However, the EU already has a disproportionately high global cropland footprint compared to the world average, and uses more cropland than domestically available to supply its demand for agricultural products. There is a risk that uncontrolled growth of the bioeconomy will increase land use pressures abroad. For that reason, a monitoring system is needed to account for the global land use of European consumption. The aim of this paper is to take a closer look at the tools needed to monitor global cropland footprints, as well as the targets needed to benchmark development. This paper reviews recent developments in land footprint accounting approaches and applies the method of global land use accounting to calculate the global cropland footprint of the EU-27 for the years between 2000 and 2011. It finds a slight decrease in per capita cropland footprints over the past decade (of around 1% annually, reaching 0.29 ha/cap in 2011) and advocates promoting a further decrease in per capita cropland requirements (of around 2% annually) to reach global land use targets for keeping consumption within the safe operating space of planetary boundaries by 2030. It argues that strategic land reduction targets may still go hand in hand with the growth of a smart, innovative and sustainable bioeconomy by reinforcing the need for policies that support greater efficiency across the life-cycle and reduce wasteful and excessive consumption practices. Recommendations for further improving land footprint accounting are given.  相似文献   

7.
Being the two largest ethanol producers in the world, biofuel policies in Brazil and the United States affect both their domestic markets and the global food and biofuel economy. In this article we develop a price endogenous mathematical programming model to simulate and analyze the impacts of biofuel mandates and trade distortions on land use, agricultural commodity and transportation fuel markets, and global environment. We find that an 80% increase in total biofuel production from its 103 billion liter baseline level to the mandated 183 billion liter level in 2022 can be achieved with less than 2% increase in total cropland use in both countries. In the United States, this would occur with cellulosic biofuels meeting nearly half of the biofuels consumed and produced largely on cropland pasture and corn ethanol meeting the rest of the mandate and resulting in a 2% increase in corn price. In Brazil, the expansion in sugarcane production would be achieved by reducing land under pasture and a marginal increase in intensification of livestock production. In the aggregate, biofuel policies increase economic surplus in both countries by 1% and redistribute the benefits from agricultural consumers to agricultural producers and the fuel sector. Finally, we also find that full implementation of the mandates in North America, China, and the European Union would reduce the global life‐cycle global greenhouse gas emissions by about 5%.  相似文献   

8.
Agricultural land abandonment is a policy challenge, especially for areas with unfavorable conditions for agriculture and remote and mountainous areas. Agricultural abandonment is an important land use process in many world regions and one of the dominant land use change processes in Europe. Previous studies have shown that abandonment can have both positive and negative effects on several environmental processes, influenced by location and scale. Preferred policies and management of these areas are debated given concerns for the loss of (traditional) agricultural landscapes and potential impacts on biodiversity and ecosystem services. We present a European-scale impact assessment of the possible effects of agricultural abandonment, based on eight indicators that are on the forefront of the agricultural abandonment debate. Using a multi-scale modelling approach, we expect between 71.277 and 211.814 km2 of agricultural abandonment in 2040. Impacts on the indicators and trade-offs between the impacts are spatially variable. A typology of typical trade-off bundles at a 1 km2 resolution resulted in four typical trade-off clusters. All clusters identified are characterized by a loss of agriculture-related values, such as agro-biodiversity and cultural heritage. For two clusters, this was accompanied by positive effects on indicators such as carbon sequestration, nature recreation and mammal habitat suitability. Overall, our results indicate that location and scale are key to assess the trade-offs originating from agricultural abandonment in Europe. Identification of typical trade-offs bundles can help to distinguish potential desirable outcomes of agricultural abandonment and assist in targeting measures to areas that face similar management challenges.  相似文献   

9.
In this study, an interval fuzzy chance-constrained land-use allocation (IFCC-LUA) model is developed for sustainable urban land-use planning management and land use policy analysis under uncertainty. This method is based on an integration of interval parameter programming (IPP), fuzzy flexible linear programming (FFLP) and chance-constrained programming (CCP) techniques. Complexities in land-use planning management system can be systematically reflected, thus applicability of the modeling process can be highly enhanced. The developed method is applied to planning land-use allocation practice in Nanjing city, China. The objective of the IFCC-LUA is maximizing net benefit from LUA system and the main constraints include investment constraints, land suitability constraints, water/power consumption constraints and wastewater/solid waste capacity constraints. Modeling results indicate that desired system benefit will be between [1.34, 1.74] × 1012 yuan under the minimum violating probabilities; the optimized areas of commercial land, industrial land, agricultural land, transportation land, residential land, water land, green land, landfill land and unused land will be [290, 393] hm2, [176, 238] hm2, [3245, 4390] hm2, [126, 170] hm2, [49, 66] hm2, [1241, 1679] hm2, [102, 138] hm2, [7, 10] hm2 and [178, 241] hm2. They can be used for generating decision alternatives and thus help decision makers identify desired land use policies under various system-reliability constraints of economic development requirement and environmental capacity of pollutant. Tradeoffs between system benefits and constraint violation risks can also be tackled.  相似文献   

10.
Between 2003 and 2013, sugarcane area expanded six-fold, from 142,000 ha to 847,000 ha, in Goiás State and the Federal District, Brazil. And while there has been much research on land-use dynamics of sugarcane expansion in established sugarcane growing regions, little is known about the dynamics associated with its expansion in sugarcane frontiers like Goiás. Understanding these dynamics provides critical information for environmental, economic, and political decisions. Here, we investigate the agricultural land-use change dynamics associated with sugarcane production in Goiás and interrogate the relationship between biophysical, institutional, and logistical factors associated with sugarcane expansion. Our results demonstrate that pasture is seven times more likely to be converted to sugarcane than soy, and most new sugarcane area was not sourced in native Cerrado vegetation. Although there exist few biophysical limitations to sugarcane expansion, capital, infrastructure, and institutions constrain production. Lastly, we show that areas where soy is currently cultivated may be converted to sugarcane in the future given the expansion of transportation and sugarcane infrastructure. Thus, we suggest incentivizing the cultivation of sugarcane on degraded pastures and supporting increased pasture stocking rates to ensure continued protection of both natural vegetation and food production while supporting the expansion of sugarcane in the state.  相似文献   

11.
This paper provides an original accounting of changes in livestock production efficiency per livestock category in historical perspective and connects livestock consumption with land requirements and virtual land trade. We use France as a demonstration study and account for productivity changes in terms of energy. Feed rations composition are reconstructed per livestock production and feed crop group over time to account for changes in land use in relation to dietary changes. Land requirements for consumption in France dropped by 28% over the study period besides an increase by 35% of the human population and by 53% of the livestock consumption. The two-fold increase in agricultural productivity is due, for half, to energy conversion efficiency improvements and for half to agricultural yields. Overall, the livestock energy conversion efficiency increased by 45% from 1961 to 2010, poultry gained 84%, pork 17%, sheep&goat 67% and cattle 27%. The feed share of oilcrops and cereals in animal rations doubled against a drop by 35% of feed from pastures. Virtual land imports for oilcrops in relation to livestock consumption in France today amount to 0.9 million ha against a maximum of 1.9 million ha in 1979. Besides its dependence on oilcrops imports, the French livestock sector displays net virtual land exports ranging from about 2.5–5.3 million ha per year over the study period. Gross virtual land trade is today five times higher than the net virtual trade. The difference highlights the share of circular product loops in increasingly integrated agricultural markets at the international scale.  相似文献   

12.
The Central American Dry Corridor (CADC) is a trans-border region characterized by climatic and ecological continuities. It is expected to experience rising aridity and severe hydro-climatic events due to climate change. Subsistence agriculture and other rural livelihoods to which land cover is central are widely practiced in this impoverished territory of approximately eleven million people.The CADC’s land cover was profiled to determine: a) how it differs from Non-CADC areas, and b) the role of land use in shaping these differences. Spatial autocorrelation analysis using satellite data showed that forest cover is a third less prevalent in the CADC than in the Non-CADC while the share of mosaic vegetation and mosaic cropland is nearly double. A naturally prevalent cover type in the CADC, tropical dry forest (TDF), has been largely eliminated.The significantly lesser proportion of forest and greater percentage of coverage consistent with agriculture and ranching implicate land use conversion, specifically deforestation for agricultural expansion and cattle ranching, in shaping CADC land coverage. The process began in the mid-1800s when small-scale agriculturalists migrated to the region followed by large-scale export crop and beef production, primarily for international markets. Deforestation peaked after WWII, concluding by the 1990s with the conversion of most woodlands. Similar patterns now threaten forests along the Caribbean coast.Traditional land use practices cannot sustain local communities or preserve the resource base, thereby contributing to rural outmigration. Adopting sustainable practices and promoting livelihoods strategies leading to forest regeneration will be fundamental for CC adaptation in the CADC.  相似文献   

13.
The western Corn Belt region of the United States has become a hotspot for agricultural extensification and consequent land use and land cover changes. The goals of this research were to characterize geographic patterns of grassland loss resulting from cropland expansion in the eastern Dakotas, and to understand how these changes were associated with characteristics of individual farms and farm operators. We collected data on grassland conversion and other land use decisions through a mail survey of farm operators in North and South Dakota. Overall, 40% of respondents converted at least some grassland to cropland between 2004 and 2014, and the total acreage of converted grassland was equivalent to 5.1% of the surveyed farm acreage. Although most converted grassland acres (3.2% of farm acreage) were from land enrolled in the conservation reserve program (CRP), there were also substantial amounts of native grassland conversion (1.0%) and tame grassland conversion (0.9%). The total acreage of grassland conversion was more than four times larger than the acreage enrolled in CRP and other conservation programs. Different types of grassland conversion (e.g., native grassland versus CRP) were concentrated in different parts of the study region, and were spatially disjunct from the areas of highest conservation program enrollment. Larger farms were more likely than smaller farms to expand their cropland acreage and accounted for a disproportionate share of grassland conversion. Younger farm operators, higher levels of farm income, higher proportions of rented croplands, and marginal yields were also associated with cropland expansion and grassland conversion. Although CRP and other land retirement programs will remain important policy mechanisms for conservation in this region, they are not sufficient to maintain current levels of grassland cover and do not provide protection for native grasslands. Alternative conservation strategies and new agricultural policies are thus critically needed to maintain the ecosystem services provided by grasslands.  相似文献   

14.
Changing dietary preferences and population growth in South Asia have resulted in increasing demand for wheat and maize, along side high and sustained demand for rice. In the highly productive northwestern Indo-Gangetic Plains of South Asia, farmers utilize groundwater irrigation to assure that at least two of these crops are sequenced on the same field within the same year. Such double cropping has had a significant and positive influence on regional agricultural productivity. But in the risk-prone and food insecure lower Eastern Indo-Gangetic Plains (EIGP), cropping is less intensive. During the dryer winter months, arable land is frequently fallowed or devoted to lower yielding rainfed legumes. Seeing opportunity to boost cereals production, particularly for rice, donors and land use policy makers have consequently reprioritized agricultural development investments in this impoverished region. Tapping groundwater for irrigation and intensified double cropping, however, is unlikely to be economically viable or environmentally sound in the EIGP. Constraints include saline shallow water tables and the prohibitively high installation and energetic extraction costs from deeper freshwater aquifers. The network of largely underutilized rivers and natural canals in the EIGP could conversely be tapped to provide less energetically and economically costly surface water irrigation (SWI). This approach is now championed by the Government of Bangladesh, which has requested USD 500 million from donors to implement land and water use policies to facilitate SWI and double cropping. Precise geospatial assessment of where freshwater flows are most prominent, or where viable fallow or low production intensity cropland is most common, however remains lacking. In response, we used remotely sensed data to identify agricultural land, detect the temporal availability of freshwater in rivers and canals, and assess crop production intensity over a three-year study period in a 33,750 km2 case study area in southwestern Bangladesh. We combined these data with georeferenced and temporally explicitly soil and water salinity information, in addition to relative elevation classifications, in order to examine the extent of winter fallows and low productivity rainfed cropland that could be irrigated by small-scale surface water pumps. Applying observations of irrigated crop sowing dates and yields from 510 wheat, 550 maize, and 553 rice farmers, we also modeled crop intensification production scenarios within the case study area. We conservatively estimate that at least 20,800 and 103,000 ha of fallow and rainfed cropland, respectively, could be brought into intensified double cropping using SWI. Scenario analysis indicates that if 25%–75% of the fallow or low-intensity land were converted to irrigated maize, national aggregate production could increase by 10–14% or 29–42%, respectively. Conversion to wheat would conversely boost national production by 9–10% or 26–31%. Irrigated rice is however unlikely to contribute >3%. In aggregate, these actions could generate between USD 36–108 million of revenue annually among farmers. Intensification therefore has important land use policy and food and income security implications, helping to rationalizei SWI investments. Crop choice, water resource allocation, and water governance will however remain crucial considerations for irrigation planners.  相似文献   

15.
Reducing carbon emissions from deforestation and forest degradation now constitutes an important strategy for mitigating climate change, particularly in developing countries with large forests. Given growing concerns about global climate change, it is all the more important to identify cases in which economic growth has not sparked excessive forest clearance. We address the recent reduction of deforestation rates in the Brazilian Amazon by conducting a statistical analysis to ascertain if different levels of environmental enforcement between two groups of municipalities had any impact on this reduction. Our analysis shows that these targeted, heightened enforcement efforts avoided as much as 10,653 km2 of deforestation, which translates into 1.44 × 10−1 Pg C in avoided emissions for the 3 y period. Moreover, most of the carbon loss and land conversion would have occurred at the expense of closed moist forests. Although such results are encouraging, we caution that significant challenges remain for Brazil's continued success in this regard, given recent changes in the forestry code, ongoing massive investments in hydro power generation, reductions of established protected areas, and growing demand for agricultural products.  相似文献   

16.
Mexico is a megadiverse country with large agroclimatic diversity and socioeconomic inequality. These two factors result in strong diversity in diets and agricultural systems within the country. In this paper, we assess the impact of Mexican diets and production systems on the per capita land requirements for food. We estimate it for the extremes: from the very basic diet of the poorest share of the population to the affluent diet of the richest share of the population; and for extensive and intensive systems, with irrigation as the indicator of the intensity of the system. We show that the basic diet produced in rainfed systems requires 1620 m2/cap/yr and produced in irrigate systems requires 700 m2/cap/yr. The affluent diet produced in rainfed systems requires 2540 m2/cap/yr and produced in irrigated systems requires 1230 m2/cap/yr. Hence, differences in diets result in a requirement for 80% or 60% more land for an affluent diet; and differences in production systems result in more than twice the amount of land for extensive than for intensive systems. In 2050, it would be possible to feed the entire population with affluent diets only if all the present area of crop land had the productivity of intensive systems. In contrast, it would be possible to feed all people with a basic diet even if all present crop land area had only the productivity of extensive systems.  相似文献   

17.
The Amazon is the largest tropical forest area on Earth, and has been undergoing rapid deforestation for the last four decades. In the Brazilian Amazon, large‐scale pasture for cattle ranching and soybean production are the main land uses, leading to a yearly deforestation rate of 0.5%. These conversions are mostly located in frontier areas distributed along the so‐called “arc of deforestation”. Within this large zone, various land use change processes are interacting through several modes of land valuation and organisation. From several case studies in the State of Pará (Brazil), the current project aims at analysing how landscape dynamics are related to infrastructure development, ecological conditions, zoning policies and to the evolution and the organisation of the production, consumption and marketing chains of livestock products. This paper presents the results for one test site, the region of São Félix do Xingú, South of Pará This region is the focus of land speculation, cattle expansion, and deforestation. Road construction, investments in electrical energy, financial credit for cattle, and the land reform policies have all fuelled this process. All these factors make this region one of the most dynamic agricultural frontiers in the Brazilian Amazon. The main objective of the paper is to improve our understanding of deforestation processes by crossing spatial analyses and 1ivestock economics.studies, and to characterise the role and impact of various natural and anthropic factors in the location and development of the main types of farmers, and their policy implications.  相似文献   

18.
A high level of fragmentation of farmland ownership is an important underlying cause of land degradation and, at the same time, an obstacle to sustainable land management. This study makes the first-ever analysis of long-term trends in the rate of fragmentation. Our study covers the period from the earliest stages of the current form of ownership patterns at the end of the 18th century until the present day. On the basis of significant predictors that have been identified (initial fragmentation, population growth, historical development of inheritance laws and of the land market, natural soil fertility and landscape type), we go on to project probable developments for the period from 2016 to 2045. A total of 102,984 land parcels in 56 cadastral units in the territory of Czechia have been analysed on the basis of data from four years (1785, 1840, 1950, 2015). Our study considers the development of two basic indicators of fragmentation – Mean Parcel Size and Number of Owners per 100 ha. The Mean Parcel Size has decreased over a period of 230 years from 1.08 ha to 0.64 ha, at a mean rate of −0.26% year−1. During the same period, the Number of Owners per 100 ha has risen from 17.50 to 79.66, at a mean rate of 0.61% year−1. A detailed analysis of the development trends confirms significant spatial variability and also time variability of the rates of the two indicators. The analysis also shows their mutual complementarity: growth in the rate of one of the indicators is usually accompanied by a drop in the other. The general trend that we project for the territory of Czechia in the upcoming 30 years is that there will be further diminution of the physical size of land parcels (continuing fragmentation of land parcels) accompanied by a reduction in the Number of Owners (defragmentation of land ownership).  相似文献   

19.
Successfully integrating human activities with ecosystem conservation forms the foundation of sustainability and is key to maintaining biological diversity. This is especially important in privately-owned lands in the U.S., which harbor high levels of biodiversity yet are often vulnerable to habitat degradation and loss. This study analyzes recreation as a sustainable use on private property, focusing on wildlife-associated recreation, defined here as fishing, hunting and wildlife watching. Eighteen national surveys implemented by three U.S. government agencies spanning 1999–2013 were analyzed to provide baseline information and an assessment of the conservation impact of recreation. Results show that approximately 440.1 million acres of private land, ∼22% of the contiguous land area of the U.S., are either leased or owned for wildlife-associated recreation. Land utilized for hunting accounts for 81% of that total. Approximately 33% of private forestland, 18% of private grazing land and 4% of private cropland is used to earn revenue from recreational activities. Annual spending for wildlife-associated recreation on private land is estimated at $814 million in day-use fees, $1.48 billion for long-term leases, and $14.8 billion to own land primarily for recreation (2011 dollars). Hunters own or lease properties of larger size classes than anglers or wildlife-watchers, indicating that hunting may provide a greater economic incentive for maintaining large unfragmented properties that provide a variety of conservation benefits. On grazing and cropland, landowners who earn income from recreation are significantly more likely to participate in government conservation programs (p < 0.001) and to pay for private conservation practices (p = 0.08). This provides support that recreation incentivizes conservation at higher rates than agricultural activities alone. Three policy measures that could further enhance conservation benefits of recreation are discussed.  相似文献   

20.
Changes in agricultural land use have important implications for environmental services. Previous studies of agricultural land‐use futures have been published indicating large uncertainty due to different model assumptions and methodologies. In this article we present a first comprehensive comparison of global agro‐economic models that have harmonized drivers of population, GDP, and biophysical yields. The comparison allows us to ask two research questions: (1) How much cropland will be used under different socioeconomic and climate change scenarios? (2) How can differences in model results be explained? The comparison includes four partial and six general equilibrium models that differ in how they model land supply and amount of potentially available land. We analyze results of two different socioeconomic scenarios and three climate scenarios (one with constant climate). Most models (7 out of 10) project an increase of cropland of 10–25% by 2050 compared to 2005 (under constant climate), but one model projects a decrease. Pasture land expands in some models, which increase the treat on natural vegetation further. Across all models most of the cropland expansion takes place in South America and sub‐Saharan Africa. In general, the strongest differences in model results are related to differences in the costs of land expansion, the endogenous productivity responses, and the assumptions about potential cropland.  相似文献   

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