Regional erosion risk mapping for decision support: A case study from West Africa

Effective soil and water management strategies require regional-scale assessment of erosion risk in order to locate prioritized area of intervention. Our study focuses on the Atacora mountain and surrounding areas (covering more than 18% of the total land area of Republic of Benin) which face a serious erosion threat despite their ecological and economic importance. To appraise the level of soil erosion risk of large area, we rely on the Instituto Nacional para la Conservación de la Naturaleza (ICONA) erosion model and use data from geographic information system (GIS). The erosion risk model requires four main inputs, namely, information on slope, lithofacies, land use and vegetation cover. The slope layer computed from ASTER digital elevation model (DEM) and the lithofacies layer inferred from digital pedogeological map are combined to draw soil erodibility map. To build soil protection map, we use land use/land cover layer extracted from LANDSAT 7 ETM + images in addition to vegetation cover layer derived from MODIS NDVI product. The final erosion risk map (with a resolution of 1 arc second) is obtained by overlapping erodibility and soil protection maps. We find that 21.8%, 58.5%, and 19.5% of the study area presents very low to low, medium, and high to very high level of erosion risk, respectively. Moreover, our findings are aggregated at the district-level (administrative unit). We observe that erosion risk is more acute in Boukoumbe district. Kerou, Kobli and Natitingou districts are mildly affected by erosion risk, while Kouande, Materi, Pehunco, Tanguieta and Toucountouna districts face a low risk. Ultimately, the proposed erosion risk map can help researchers and decision makers design and implement effective soil and water management interventions in the study area.     

An interval fuzzy chance-constrained programming model for sustainable urban land-use planning and land use policy analysis

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.     

Fostering integrated land and water management approaches: Evaluating the water footprint of a Mediterranean basin under different agricultural land use scenarios

In the Genil River Basin (southern Spain), agriculture is the greatest pressure on freshwater demand. Furthermore, water degradation caused by soil erosion is becoming a key environmental concern. This study aims to assess the water-related impacts of agriculture combining the use of an ecohydrological model (SWAT) with a spatiotemporal water footprint assessment to evaluate the current status of streamflow (blue water), soil water (green water) and the assimilability of sediments by streamflow (grey water footprint). The Common Agricultural Policy (CAP) requires farmers to adopt certain agricultural practices that are beneficial for the environment. Such practices could affect the conditions of available land and water resources. Because of the importance of applying the best land management practices for the maintenance of sustainable water resources, the study also infers probable water availability and water pollution level changes under different post-2013 CAP scenarios. The Genil streamflow is highly regulated, and, as a result, it is hard to discern significant changes (p < 0.05) under the proposed scenarios. However, there is a shift with afforestation measures from unproductive (i.e., direct soil evaporation) to productive water (i.e., evapotranspired water from agricultural and natural areas, excluding non-growing periods) consumption. The probability of annual evapotranspiration from natural areas being greater in afforestation scenarios than in the baseline scenario is 0.70 to 0.88, whereas the likelihood of soil water evaporation being lower is 0.60. Evapotranspiration in natural areas increases by about 521% from September to May under afforestation measures compared with the baseline scenario, whereas soil water evaporation decreases by 30% in winter. The grey water footprint and water pollution level decrease by 19% and 9%, respectively, with the highest streamflow conditions under afforestation as opposed to current conditions. However, water pollution levels of suspended solids greater than 1 indicate that the river flow is not capable of assimilating the existing sediment loads. Since land use changes and agricultural practices have a major impact on water resources, the post-2013 CAP reform can provide environmental benefits for water allocation and mitigation of water pollution. However, further efforts are required to better align the policy goals of the CAP and the Water Framework Directive.     

An interactive land use transition agent-based model (ILUTABM): Endogenizing human-environment interactions in the Western Missisquoi Watershed

Forest Transition Theory (FTT) suggests that reforestation may follow deforestation as a result of and interplay between changing social, economic and ecological conditions. We develop a simplistic but empirically data driven land use transition agent-based modeling platform, interactive land use transition agent-based model (ILUTABM), that is able to reproduce the observed land use patterns and link the forest transition to parcel-level heuristic-based land use decisions and ecosystem service (ES). The ILUTABM endogenously links landowners’ land use decisions with ecosystem services (ES) provided by the lands by treating both lands and landowners as interacting agents. The ILUTABM simulates both the land use changes resulting from farmers’ decision behaviors as well as the recursive effects of changing land uses on farmers’ decision behaviors. The ILUTABM is calibrated and validated at 30 m × 30 m spatial resolution using National Land Cover Data (NLCD) 1992, 2001 and 2006 across the western Missisquoi watershed, which is located in the north-eastern US with an estimated area of 283 square kilometers and 312 farmers farming on 16% of the total Missisquoi watershed area. This study hypothesizes that farmers’ land use decisions are made primarily based on their summed expected utilities and that impacts of exogenous socio-economic factors, such as natural disasters, public policies and institutional/social reforms, on farmers’ expected utilities can significantly influence the land use transitions between agricultural and forested lands. Monte Carlo experiments under six various socio-economic conditions combined with different ES valuation schemes are used to assess the sensitivities of the ILUTABM. Goodness-of-fit measures confirm that the ILUTABM is able to reproduce 62% of the observed land use transitions. However, the spatial patterns of the observed land used transitions are more clustered than the simulated counterparts. We find that, when farmers value food provisioning Ecosystem Services (ES) more than other ES (e.g., soil and water regulation), deforestation is observed. However, when farmers value less food provisioning than other ES or they value food provisioning and other ES equally, the forest transition is observed. The ILUTABM advances the Forest Transition Theory (FTT) framework by endogenizing the interactions of socio-ecological feedbacks and socio-economic factors in a generalizable model that can be calibrated with empirical data.     

Long-term impact of socio-economic changes on agricultural land use in the Polish Carpathians

The impact of socio-economic changes on land use on the period 1846–2009 are studied in village of Ochotnica (105 km²) and the Jaszcze and Jamne catchments in the Polish Carpathians. The analysis of maps, aerial photos, historical and census reports indicates that during the investigated period the forest area in Ochotnica increased by 77% and in the Jaszcze and Jamne catchments by 29% and 43%, respectively and cultivated land decreased by 94% in both catchments. The population density increased from 33 to more than 50 people/km², while employment in agriculture decreased from 98% to below 30%. The analysed period shows diverging trends of land use, referring to the three stages of socio-economic development in the Polish Carpathians. Until World War II, agricultural land contribution was the highest throughout the history of human activity. After World War II, a communist maintenance system of the land use structure was inherited from the past. A free market economy, introduced after 1989, forced the largest increase in forest area since the first colonisation of the Gorce Mountains. In contrast to the mid-mountains of Western Europe, a decrease in population density did not accompany forest expansion, nor did a dominance of small farms in the ownership system.     

Changes of livelihood due to land use shifts: A case study of Yanchang County in the Loess Plateau of China

Studies of land use policies are commonly based on the environmental impacts or on people's direct responses to the policies. However, research on the impact of policy implementation on people's livelihood and activities and the subsequent economic development of an area is incomplete. We selected Yanchang County as an example to track land use changes and their effects on the livelihood of the local population following the implementation of a new land use policy known as the Grain for Green Project (GGP). The data were collected from statistical yearbooks, questionnaire surveys, and satellite imagery from 1990, 2000, and 2008. We found that dramatic land use changes have occurred in Yanchang County. The vegetation coverage improved significantly from 1990 to 2008, as the grassland and forest areas increased from 44.1% to 60.1% and from 17.7% to 18.4% of the total land area, respectively. The cultivated land declined from 37.3% to 20.7%. With the agricultural area and grain production decreasing from 64 × 10³ tons to slightly over 20 × 10³ tons per year, an increasing number of local people sought employment in towns and cities. The non-farm income increased, and the local income structure shifted. Migrant and orchard worker income contributed the most to the balance of the total household income. We narrowed our focus to discuss how the GGP accelerated the changes in the participants’ lifestyles and what might be done to sustain the long-term effects of the GGP. While the GGP has brought about considerable environmental benefits, a comprehensive study of environmental–social systems is still needed to achieve a more efficient land use policy. The research results presented in this paper demonstrate that changes in land use and people's activities were triggered by policy changes. We aim to pave the way for studies on the “policy-land-use-social development” chain and to provide references for new policies.     

Diversity of Mexican diets and agricultural systems and their impact on the land requirements for food

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.     

The retention ability of the agricultural landscape in the emergency planning zone of the Temelín nuclear power plant and its changes since the 19th century

Drainage and loss of wetland sites is a major problem of the agricultural landscape, as it reduces the landscape’s ability to retain water, nutrients, matter, and minimize erosion. With this in mind, the issue of the ability of wet sites to retain radionuclides and contaminated water in the case of a radiation accident was studied. In 2013, field research examined the occurrence of wetland retention sites in the emergency planning zone (EPZ) of the Temelín nuclear power plant (NPP; Czech Republic). As data sources, wetland biotopes (European network Natura 2000) were considered; in addition, retention features were field mapped, i.e. landscape elements of a wetland nature not normally considered nationally significant for conservation. Within the emergency zone, 2854.7 ha of wetland biotopes were registered and 318.9 ha retention features mapped. Density of retention sites (in ha/km²) per cadastre (local administrative units) was used to represent their spatial distribution within the zone. For an assessment of possible revitalization measures, leading to an increase in the landscape’s retention ability, spatial changes in the area of retention sites between 2013 and the mid-19th century, a period before extensive drainage of landscape occurred and a simplification of its structure, were mapped. Historic land maps (The Imperial Obligatory Imprints of the Stable Cadastre) were used as a basis of information on the occurrence and area of fens and wet meadows (4771.5 ha).For spatial comparisons of drained and undrained landscape in the past and present, the density of retention sites per cadastre was calculated. In the mid-19th century, 80% of cadastres had a density of retention sites exceeded 5 ha/km²; in 2013 only 40% of cadastres achieved this. In the most part, drained areas of the zone belong to the central part (around the power plant), as well as the EPZ’s eastern and south-eastern regions. From the density maps of retention sites, as well as from the stable cadastre imprints, it is possible to identify areas and retention features suitable for wetland restoration, thus leading to an increase in the retention capacity of the landscape in terms of water and radionuclide retention. Suggestions as to how to restore and turn retention features into semi-natural wetlands, as well as integrating small wetlands into an agriculture landscape are outlined.     

Managing tropical wetlands for advancing global rice production: Implications for land-use management

Being fertile lands, wetlands have been managed for traditional agriculture over millennia. However, the integrity and ecosystem services of wetlands are being jeopardized by intensive land-use comprising of drainage and excessive disturbance. An adhoc and intensive use of wetlands, without preserving ecological integrity is causing ecosystem disservices and threatening conversion of a large soil organic carbon (SOC) sink into a net source. Wetlands in the tropical parts of the world are distributed unevenly and represent ∼3% of the total world land area. Due to stagnancy and even reduction in rice (Oryza sativa) yield of many agricultural regions, there is a need for additional and alternative land-uses which can raise the global rice production to ∼1 billion Mg (megagram = 10⁶g = metric ton) by 2050 from ∼497 million Mg now. Wetlands can be a viable option to advance global food security because of high soil fertility and vast geographical distribution. A ‘3-tier rice production system’ is proposed herein based on specific hydrological niche to advance global food security without degrading the ecosystem services of wetlands. In addition to increasing agronomic yield, the proposed modus operandi can also improve the livelihood security of farmers through an additional income streams by: (i) trading of SOC credits generated through adoption of conservation agriculture in littoral zones, and (ii) promoting fish and duckery culture in conjunction with deepwater rice farming. Furthermore, the proposed strategies will also set in motion the process of restoration of wetlands while enhancing C sink capacity of the ecosystems.     

Risk analysis of water scarcity in artificial woodlands of semi-arid and arid China

All activities are inherently risky, including seemingly beneficial activities such as ecological restoration. However, small risks are easy to ignore, even if they may accumulate to create a large cumulative risk. Therefore, the long-term ecological benefits and risks of any ecological restoration project must both be considered. However, quantitative evaluation of the risk of afforestation in arid and semi-arid regions has been insufficiently studied. Here, we present a method for evaluating the risk associated with ecological restoration, using water shortages in artificial woodlands in China’s arid and semi-arid regions as an example of cumulative risk. We found an annual risk that amounted to 5174 RMB ha⁻¹ in 2014, which was 17% of the ecological service value of the forests. However, this cost depends on changes in the price, availability, and use of water in these regions. If ecological degradation occurs, it will trigger a series of serious consequences, and its cost may far exceed the expected benefits. Our inability to predict natural disasters such as drought and the problem of imperfect communication among stakeholders must be considered to achieve ecological restoration. The method described in this paper will provide theoretical support for future risk evaluations and guidance for the allocation of natural resources such as water, thereby increasing the likelihood of successful environmental management.     

Public policies can reduce tropical deforestation: Lessons and challenges from Brazil

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.     

The role of wildlife-associated recreation in private land use and conservation: Providing the missing baseline

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.     

Assessing the efficiency of switchgrass different cultural practices for pellet production

Switchgrass is a perennial crop producing high amounts of biomass for good quality pellet production. The objective of this study is to examine the efficiency of different cultural practices of switchgrass for pellet production under field conditions for four different N-fertilization (0, 80, 160 and 240 kg ha⁻¹) and two different irrigation levels (0 and 250 mm), in two soils in central Greece with rather different moisture status over the period 2009–2012. Moreover, comparison between three harvest methods (two different types of bales and silage) was made. The results derived from this study revealed that the bale at 22 kg is the harvesting practice with the highest costs while there was reduction of efficiency scores when nitrogen levels increased. At both environments the efficiency scores followed the same trend, confirming that low levels of nitrogen fertilization enhance the economic competitiveness of switchgrass production. Palamas site is the area where switchgrass for pellet production had positive income ranging from 400 to 1600 € ha⁻¹, while Velestino site had always negative. Therefore, places like Velestino with non-aquic soil should be avoided for switchgrass. These data suggest that growing switchgrass for solid biofuel production as energy crop is a worthwhile decision only in areas with a moderately shallow groundwater table (aquic soil) or maybe in high precipitation regions.     

Changes of urbanised landscape identified and assessed by the Urban Atlas data: Case study of Prague and Bratislava

Identification, analysis and assessment of changes in the urbanised landscape, one of the most conspicuous transforming parts of earth surfaces, has become the topic of numerous research projects. However, there is still a lack of compatible data suitable for the generation of topical information about the urbanised landscape and its changes at different scales. An important contribution in this sense is the Urban Atlas (UA) Project pursued under the GMES (Global Monitoring for Environment and Security)/Copernicus Land (GIO land) Programme auspiced by the European Commission. The aim of this study is to document, examine and compare land use/cover change (LUCC) of the LUZs (Large Urban Zones) of Bratislava and Prague in 2006–2012 by means of the UA data and show how these changes are captured in official statistical data. Results confirmed the present trends in modern industrial cities dominating by transforming the agricultural land into residential and industrial areas. Dispersion of the urban fabric into locations previously used for agriculture was mostly widespread in LUZ Prague (1,718 ha). This trend has also been partially confirmed by the change of agricultural land in favour of construction sites, the most pronounced one in LUZ Bratislava (580 ha). Assessment and comparisons of LUCC changes of LUZs Bratislava and Prague proved that combining the UA data and official statistical data has a great potential for insight into the dynamics of the urbanised landscape of Europe.     

Sustainable crop intensification through surface water irrigation in Bangladesh? A geospatial assessment of landscape-scale production potential

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.     

Carbon storage in a bamboo (Bambusa vulgaris) plantation in the degraded tropical forests: Implications for policy development

Tropical forests potentially contribute to global climate change mitigation through carbon sequestration, hence a global carbon pool. In order to mitigate the global climate change impact, the Kyoto protocol developed the clean development mechanism (CDM) which supports carbon credits for plantation activities in developing countries. Unfortunately, none of the CDM forestry projects included bamboo as a carbon reservoir. Although bamboo is an integrating part of tropical forest ecosystems, it was overlooked in the initial negotiating process. The present study, therefore, investigated the carbon storage potential of a common bamboo species, Bambusa vulgaris at Lawachara forest reserve of Bangladesh. Results showed that five-year-old B. vulgaris stand stored in total 77.67 t C ha⁻¹ of which 50.44 t C ha⁻¹ were stored in the above ground biomass (culms, branches and leaves), 2.52 t C ha⁻¹ in the below ground biomass and 24.71 t C ha⁻¹ in the soils. This amount of carbon storage is much more promising than the carbon storage of many other tree species considered in the CDM projects. These findings demonstrate the potential of B. vulgaris to be considered in CDM projects as a plantation species and thereby mitigate climate change impact more efficiently.     

One federal policy,four different policy contexts: An examination of agri-environmental policy implementation in the Midwestern United States

Much research attention has been given to devolved environmental policies and variation in state adoption of environmental policies. Less attention has been paid to variation in top-down federal policies, including in the agri-environmental arena. The Environmental Quality Incentives Program (EQIP) is the largest working land conservation program in the United States, incentivizing the adoption of conservation practices on active agricultural land through cost-share and technical assistance. While the program is federal, state offices of the Natural Resources Conservation Service (NRCS) are charged with implementing the program in their state. Qualitative interviews (n = 26) were conducted with NRCS personnel in four Midwestern states to explore similarities and differences between state administrative outputs. Program outputs are determined through a mixture of national, state, and local administrative processes and are driven by dissimilarities in state resource concerns and agricultural systems. The process by which farmers apply for cost-share funding through EQIP is largely the same across states, but states vary in several important outputs, especially resource and conservation practice priority, as well as state and local partnerships. Outreach methods do not tend to vary between states; NRCS districts typically rely on passive recruitment and word-of-mouth recruitment. Divergence in state EQIP outputs constitute a significant difference in the policy context in which farmers make conservation decisions in the Midwest, which has implications for research concerning farmer behavior. While federal policies implemented across the states offer some level of consistency in the setting in which individual land managers make decisions, variation may still exist in many policies that results in different policy outputs.     

Forest fragmentation reduced carbon storage in a moist tropical forest in Bangladesh: Implications for policy development

Forest fragmentation is continued to be widespread in the tropics resulting in reduced ecosystem services including carbon storage. However, the effect of forest fragmentation is not considered in the current carbon policy. We investigated the effect of forest fragmentation on tree biomass carbon and soil organic carbon (SOC) storage in a moist tropical forest in Bangladesh. Above and below-ground tree biomass carbon were calculated by using widely accepted allometric equations and SOC was measured by sampling soils up to 10 cm depth and analyzing them in a soil laboratory. Results showed that carbon storage in tree biomass was significantly lower in fragmented forests (16.3 ± 1.37 t C ha⁻¹) than in contiguous forests (31.21 ± 2.75 t C ha⁻¹) (p < 0.001). Likewise, a significantly lower SOC was contained in the soils of fragmented forests (17.26 ± 0.83 t C ha⁻¹) than in contiguous forests (21.62 ± 0.78 t C ha⁻¹) (p < 0.001). Thus a total of 36% less carbon retained in tree biomass and soils in fragmented forests than in contiguous forests. Backward multiple linear regression analysis revealed tree density, tree height, tree DBH, height-diameter ratio (H/D) and tree species richness as influential factors of carbon variation in fragmented forests. All these structural parameters except tree species richness were significantly lower in fragmented forests, were positively associated with carbon storage and explained together 69% of the carbon storage variation. These findings suggest that the altered stand structure and tree allometry likely caused reduced carbon storage in fragmented forests and highlight the importance of landscape scale management intervention in the tropics. Here, we provided with the evidence of strong negative impact of forest fragmentation on carbon storage and argue that this effect should be in consideration which is currently overlooked in existing carbon accounting systems for tropical forests.     

A novel approach for assessing the contribution of agricultural systems to the sustainable development of regions with multi-scale indicators: Application to Guadeloupe

The assessment of agriculture at a regional scale is necessary to better guide regional agricultural planning. To improve the contribution of agriculture to sustainable regional development, assessments must take account of the locations and diversity of cropping systems. We have therefore developed a method based on a set of multi-scale indicators to assess the contribution of agriculture to the sustainable development of regions, and its evolution over time. This method can identify: i) sustainability issues, ii) relevant indicators that will provide information on impacts at the field scale, iii) a method to aggregate indicators, iv) data on cropping systems, and v) a database containing spatial units to analyse the whole region. Application of this method to Guadeloupe (2004–2010) enabled the definition of ten issues and 16 indicators, with three procedures to aggregate information from 36 cropping systems allocated to 11,908 fields between 2004 and 2010. Economic, social and environmental sustainability was poor in 2004, with high dependency on subsidies (47.3 M€ yr⁻¹), low agricultural added value (48.5 M€ yr⁻¹), low employment (only 1799 workers), significant risks of crop contamination and pressure on water quality. The total value of subsidies and the risks of river pollution tended to decrease between 2004 and 2010 because of a reduction in intensive banana cropping systems. In parallel, we were able to see that sugar cane, the most widespread crop in Guadeloupe, made only a small contribution to employment and food self-sufficiency during the studied period. The spatial representation revealed that improvements have been seen in southern Guadeloupe due to reductions in banana cultivation. This method was therefore helpful in identifying the most critical agricultural development issues and helping to highlight areas where relevant agricultural land use policies could be formulated.     

A legal framework with scientific basis for applying the ‘polluter pays principle’ to soil conservation in rural watersheds in Brazil

The “polluter pays principle” (PPP) has been looked at from the perspective of legal values and technical principles, namely of soil science, to evaluate the acceleration of soil erosion and the consequent development of degraded areas in the Uberaba River basin (area: 2419 km²), state of Minas Gerais, Brazil. Having accomplished this goal, the study highlights the importance of PPP for the conservation of soil and development of an ecologically equilibrated environment. The diagnosis of degraded areas was based on the coupling of a Geographic Information System with soil loss, land use conflict and tolerance to soil loss models, and revealed a preoccupying situation because an extension of approximately 905 km² (1/3 of the basin) has been considered in advanced state of degradation potentially causing environmental damage (e.g., decline of soil fertility and hence crop production, negative impacts of soil particles export on stream and lake water quality and biodiversity of riverine ecosystems). Facing this problem, a legal framework standing on doctrinaire principles, federal laws and the Brazilian Constitution has been proposed whereby the protagonists of soil degradation are called to assume responsibility as well as the costs of repairing this negative condition. Although the study has been carried out on a specific country under pre-defined settings, the rationale behind the proposals can easily be transposed to other scenarios because the scientific methods on which soil degradation has been defined and mapped are generally applicable, while the suggested legal values are currently applied to many regions on the planet.