Agricultural Conversion Research Articles

Farmer Exchange Rate and Agricultural Land Conversion Analysis to Agricultural Sector Poverty in Indonesia

The agricultural sector poverty in Indonesia is affected by some factors like income and agricultural land area. Farmer exchange rate is an indicator of farmer welfare that can be a measurement of farmer real income. Farmer exchange rate tends to be increased from 2009 to 2013. Besides, the agricultural land area tends to decrease that time. Decreasing of agricultural land is caused by agricultural land usage conversion. This research aims to analyze direct and indirect effects of farmer exchange rate and agricultural land conversion toward agricultural sector poverty in Indonesia, with the objects of 33 provinces in Indonesia (excludes North Kalimantan) from 2009 until 2013. This research is using path analysis to obtain the result, with agricultural laborer variable and agricultural productivity as intervening variables. The result obtained that farmer exchange rate has a direct and indirect effect toward agricultural sector poverty, besides agricultural land conversion has an indirect effect toward agricultural sector poverty. Keywords : Farmer Exchange Rate, Agricultural Land Conversion, Agricultural Productivity, Agricultural Sector Poverty JEL Classification: I32, Q01, Q24

Novidades (Novelty) na Agricultura Familiar e sua associação com a agroecologia na produção de hortifrutigranjeiros no Território Sertão do Apodi (RN)

O objetivo do artigo é destacar práticas e manejos na produção de hortifrutigranjeiros do território Sertão do Apodi em experiências que associam a agricultura familiar com a agroecologia. E uma das iniciativas é trazer a abordagem das novidades e das inovações como contraponto aos modelos exógenos da agricultura moderna, sendo alternativa para o desenvolvimento rural e regional ancorado na agricultura familiar. Como procedimentos metodológicos, foram aplicados questionários com agricultores familiares que associam a sua produção agroecológica com a venda direta dos seus produtos, objetivando informações sobre a produção agroecológica e segurança alimentar. Diante disso, a pesquisa revelou a necessidade da agricultura familiar se adequar às exigências da legislação para a inserção em mercados, em que as novidades e a inovação na produção agroecológica devem acontecer no sentido de respeitar o ambiente e possibilitar a segurança alimentar e nutricional construindo a relação de confiança entre agricultores e consumidores. Por fim, apesar das limitações, os agricultores familiares têm potencial significativo para o desenvolvimento regional, com a conversão da agricultura moderna e produtivista para sistemas agroecológicos.

Endogenous Forest Development Paradigm: Challenging Current Forest Conservation Practices in Ghana

The centre of Ghana development is land that plays a vital role. This article focused mainly on the rapid land degradation and deforestation due to bush fires, poorly managed grazing, farming and agricultural conversion, current forest/woodland governance systems and major policy gaps that were identified. A combination of methods used included: Extensive study of secondary literature/reports/programmes/write-ups (from 1999-2004), key informant interview: a one-on-one interview with Government Officials, 7 responsible for forest management, Forestry, Commission and Traditional Institutions (men-10, women-5), elders-6, and functionaries-4 living in the community, phased assertion. The study recommend Forest Management System needs to be evolved that includes the management and development of sacred groves, shrines, sacred bodies and natures, and totems; associated with indigenous agricultural practices and seeds, indigenous agro-ecological management practices, indigenous tree and vegetation management practices, indigenous livelihood developments and human activity systems which are both enhancing and militating against biodiversity conservation and development encourage and systematically develop traditionally protect areas/plants/animals (TPAs). Attention should be paid to conservation of: 1) sacred groves; 2) burial grounds and spiritual lands; 3) sacred water bodies and fauna; 4) totemic animals; 5) traditional cultural practices; 6) farming systems; 7) traditional crop varieties; 8) home gardens; 9) graze-lands and rest lands; 10) wild fruits supply systems.

Beyond pattern to process: current themes and future directions for the conservation of woodland birds through restoration plantings

Habitat loss as a result of land conversion for agriculture is a leading cause of global biodiversity loss and altered ecosystem processes. Restoration plantings are an increasingly common strategy to address habitat loss in fragmented agricultural landscapes. However, the capacity of restoration plantings to support reproducing populations of native plants and animals is rarely measured or monitored. This review focuses on avifaunal response to revegetation in Australian temperate woodlands, one of the world’s most heavily altered biomes. Woodland birds are a species assemblage of conservation concern, but only limited research to date has gone beyond pattern data and occupancy trends to examine whether they persist and breed in restoration plantings. Moreover, habitat quality and resource availability, including food, nesting sites and adequate protection from predation, remain largely unquantified. Several studies have found that some bird species, including species of conservation concern, will preferentially occupy restoration plantings relative to remnant woodland patches. However, detailed empirical research to verify long-term population growth, colonisation and extinction dynamics is lacking. If restoration plantings are preferentially occupied but fail to provide sufficient quality habitat for woodland birds to form breeding populations, they may act as ecological traps, exacerbating population declines. Monitoring breeding success and site fidelity are under-utilised pathways to understanding which, if any, bird species are being supported by restoration plantings in the long term. There has been limited research on these topics internationally, and almost none in Australian temperate woodland systems. Key knowledge gaps centre on provision of food resources, formation of optimal foraging patterns, nest-predation levels and the prevalence of primary predators, the role of brood parasitism, and the effects of patch size and isolation on resource availability and population dynamics in a restoration context. To ensure that restoration plantings benefit woodland birds and are cost-effective as conservation strategies, the knowledge gaps identified by this review should be investigated as priorities in future research.

EXPANSÃO URBANA E ALTERAÇÕES DO USO E COBERTURA DO SOLO NO MUNICÍPIO DE CANOAS (RIO GRANDE DO SUL) NO PERÍODO 1984 A 2014

Canoas, município da Região Metropolitana de Porto Alegre, registrou um vertiginoso crescimento populacional durante o século XX, fundamentado no loteamento precário em áreas sujeitas à inundação. O objetivo deste estudo foi avaliar o processo de expansão urbana entre 1984-2014 no atual território do município. A partir da interpretação visual de quatro imagens do satélite Landsat 5TM e uma do satélite Landsat 8, foram gerados cinco mapas de uso e cobertura do solo. Ao todo dez classes foram identificadas no município. Posteriormente, os mapas foram sobrepostos para calcular uma matriz de tabulação cruzada, a partir da qual todas as alterações detectadas entre as classes foram computadas em termos de extensão e proporção de área, para todos os períodos avaliados. Os resultados mostram fortes contrastes nos padrões de uso e cobertura do solo entre os setores a leste e oeste de Canoas, separados pelo eixo viário metropolitano que ao mesmo tempo dividiu e impulsionou seu crescimento a cidade. No período entre 1984-2002, a expansão urbana se deu de maneira intensa e informal, ocorrendo principalmente sobre áreas de atividade agrícola, e de vegetação nativa e exótica. Entre 2002-2014, a urbanização foi menos intensa, ocorrendo principalmente sobre áreas de campo e solo exposto. Ao longo dos 30 anos, houve ampliação das matas nativas e dos banhados. Em contrapartida, ocorreu uma forte redução das áreas de atividade agrícola e de campo. Conclui-se que das grandes glebas passíveis de urbanização remanescentes, a maior parte está em áreas sujeitas à inundação.

Hydrogeological controls on spatial patterns of groundwater discharge in peatlands

Abstract. Peatland environments provide important ecosystem services including water and carbon storage, nutrient processing and retention, and wildlife habitat. However, these systems and the services they provide have been degraded through historical anthropogenic agricultural conversion and dewatering practices. Effective wetland restoration requires incorporating site hydrology and understanding groundwater discharge spatial patterns. Groundwater discharge maintains wetland ecosystems by providing relatively stable hydrologic conditions, nutrient inputs, and thermal buffering important for ecological structure and function; however, a comprehensive site-specific evaluation is rarely feasible for such resource-constrained projects. An improved process-based understanding of groundwater discharge in peatlands may help guide ecological restoration design without the need for invasive methodologies and detailed site-specific investigation. Here we examine a kettle-hole peatland in southeast Massachusetts historically modified for commercial cranberry farming. During the time of our investigation, a large process-based ecological restoration project was in the assessment and design phases. To gain insight into the drivers of site hydrology, we evaluated the spatial patterning of groundwater discharge and the subsurface structure of the peatland complex using heat-tracing methods and ground-penetrating radar. Our results illustrate that two groundwater discharge processes contribute to the peatland hydrologic system: diffuse lower-flux marginal matrix seepage and discrete higher-flux preferential-flow-path seepage. Both types of groundwater discharge develop through interactions with subsurface peatland basin structure, often where the basin slope is at a high angle to the regional groundwater gradient. These field observations indicate strong correlation between subsurface structures and surficial groundwater discharge. Understanding these general patterns may allow resource managers to more efficiently predict and locate groundwater seepage, confirm these using remote sensing technologies, and incorporate this information into restoration design for these critical ecosystems.

Orange Wood for Parquet and Engineered Flooring Use

Orange is a fruit of the Citrus genus in the family Rutaceae. It is assumed to have originated in southern Asia, and to have been first cultivated in China around 2500 BC. There is little knowledge on the quality of wood from orange trees, which is occasionally used in fine woodwork, tool handles, mosaics, and marquetry. This work aimed to evaluate the possibility of using orange wood from agricultural conversions and orchard plantation renewals to make products with a high value. Logs from plantations located in southern Italy were collected, and the key aspects for determining the suitability of using the wood as flooring were examined. Laboratory tests were carried out to determine the shrinkage, dimensional stability, and surface hardness, which included an indentation test on the wood flooring. Drying trials were also performed, and prototypes of flooring were prepared so professionals and end users could evaluate the aesthetic value. The results confirmed that the wood from orange trees is fine-grained, and is characterized by a high density and shrinkage, average dimensional stability, and high surface hardness. The results of the tests suggested performing careful drying and following specific procedures according to the size of the elements. The wood was highly appreciated by the users, which confirmed the possibility of using this wood as a renewable raw material, despite the limited availability, for manufacturing high-quality products.

Why are tropical mountain passes "low" for some species? Genetic and stable-isotope tests for differentiation, migration and expansion in elevational generalist songbirds.

Most tropical bird species have narrow elevational ranges, likely reflecting climatic specialization. This is consistent with Janzen's Rule, the tendency for mountain passes to be effectively "higher" in the tropics. Hence, those few tropical species that occur across broad elevational gradients (elevational generalists) represent a contradiction to Janzen's Rule. Here, we aim to address the following questions. Are elevational generalists being sundered by diversifying selection along the gradient? Does elevational movement cause these species to resist diversification or specialization? Have they recently expanded, suggesting that elevational generalism is short-lived in geological time? To answer these questions, we tested for differentiation, movement and expansion in four elevational generalist songbird species on the Andean west slope. We used morphology and mtDNA to test for genetic differentiation between high- and low-elevation populations. To test for elevational movements, we measured hydrogen isotope (δ2 H) values of metabolically inert feathers and metabolically active liver. Morphology differed for House Wren (Troglodytes aedon) and Hooded Siskin (Spinus magellanicus), but not for Cinereous Conebill (Conirostrum cinereum) and Rufous-collared Sparrow (Zonotrichia capensis) respectively. mtDNA was structured by elevation only in Z.capensis. δ2 H data indicated elevational movements by two tree- and shrub-foraging species with moderate-to-high vagility (C.cinereum and S.magellanicus), and sedentary behaviour by two terrestrial-foraging species with low-to-moderate vagility (T.aedon and Z.capensis). In S.magellanicus, elevational movements and lack of mtDNA structure contrast with striking morphological divergence, suggesting strong diversifying selection on body proportions across the c. 50km gradient. All species except C.cinereum exhibited mtDNA haplotype variation consistent with recent population expansion across the elevational gradient, potentially concurrent with Holocene anthropogenic habitat conversion for agriculture. In different ways, each species defies the tendency for tropical birds to have long-term stable distributions and sedentary habits. We conclude that tropical elevational generalism is rare due to evolutionary instability.

Cambios de cobertura y uso de suelo: estudio de caso en Progreso Hidalgo, Estado de México

Actualmente, en Progreso Hidalgo la pérdida de la rentabilidad y de la capacidad productiva agrícola está ocasionando cambios en las coberturas de uso de suelo y vegetación (conversión agrícola), uno de ellos es la implementación de la producción agrícola en invernaderos. Por lo cual la presente investigación tiene por objetivo analizar los cambios de cobertura y uso de suelo para los periodos 2000-2007 y 2007-2015, mediante mapas de uso de suelo y vegetación, resultado de la interpretación visual interdependiente de insumos cartográficos, para comprender los procesos de cambio y la dinámica de uso de suelo que determina a la zona. Los mapas obtenidos fueron sometidos a la validación cartográfica para conocer su grado de confiabilidad temática. Por medio de la sobreposición de dichos mapas se determinaron los indicadores de cambio, índices de Braimoh y las tasas de cambio. Los resultados alcanzados expresan que, para el periodo 2000-2007, las categorías de agricultura (de temporal y riego) y bosque decrecieron, puesto que se perdieron 23.04 ha y 16.76 ha, respectivamente. Por su parte, la cobertura que obtuvo mayores ganancias fueron los invernaderos con 5.19 ha, mientras que para el periodo 2007-2015 la agricultura perdió 18.71 ha, pasando a invernaderos 14.39 ha. La pérdida de la superficie agrícola es producto de la implementación y expansión de nuevos espacios destinados a la producción agrícola en invernaderos, condicionados principalmente por factores ambientales (protección de cultivos y tipo, estado y condición del suelo) y socioeconómicos (programas gubernamentales, accesibilidad, cantidad de producción y tipo comercialización).

Wetland-atmosphere methane exchange in Northeast China: A comparison of permafrost peatland and freshwater wetlands

Northeast China contains a large concentration of wetlands, primarily in two prominent types, freshwater marshes on the lowlands plains to the northeast and mountain permafrost peatlands in the north. Both wetlands types are threatened by disturbance, the marshes from agricultural conversion and the peatlands due to climate warming and loss of permafrost. Here we compare two seasons of ecosystem-scale CH4 fluxes measured via eddy covariance for a permafrost peatland in the Da Xing’anling Mountains and a freshwater marsh on the Sanjiang Plain. The objectives were to quantify CH4 fluxes, compare seasonal trends in the flux and determine the dominant environmental and biophysical drivers of the CH4 flux for these two distinct wetland types.CH4 fluxes at the marsh had a strong seasonal trend peaking in mid-summer, while the pattern for the peatland was muted. Maximum instantaneous fluxes were 1.34μg CH4 m−2s−1 and 9.5μg CH4 m−2s−1 at the peatland and marsh, respectively. Total seasonal CH4 emissions for the peatland, 0.38–1.27g C-CH4 m−2, were an order of magnitude smaller than those at the marsh, 19.71–21.8g C-CH4 m−2. Differences between years were small for both wetlands. We used path analysis to examine environmental and biophysical drivers of the flux and found that soil temperature (average soil temperature between 10cm to 60cm depths for the peatland and 10cm depth for the marsh) was most strongly correlated with seasonal CH4 variability for both wetlands. Secondary influences were thaw depth for the peatland and net ecosystem CO2 exchange for the marsh.Given the temperature sensitivity of CH4 flux for both of these wetlands, future climate warming will likely increase CH4 emissions in northeast China, as well, the continued loss of permafrost in the mountain peatlands will likely further contribute to enhanced CH4 emissions.

Habitat attribute similarities reduce impacts of land‐use conversion on seed removal

AbstractChanges in land use strongly influence habitat attributes (e.g., herbaceous ground cover and tree richness) and can consequently affect ecological functions. Most studies have focused on the response of these ecological functions to land‐use changes within only a single vegetation type. These studies have often focused solely on agricultural conversion of forests, making it nearly impossible to draw general conclusions across other vegetation types or with other land‐use changes (e.g., afforestation). We examined the consequences of agricultural conversion for seed removal by ants in native grassland, savanna, and savanna‐forest habitats that had been transformed to planted pastures (Brachiaria decumbens) and tree plantations (Eucalyptus spp.) and explored if changes in seed removal were correlated with differences in habitat attributes between habitat types. We found that land‐use changes affected seed removal across the tree cover gradient and that the magnitude of impact was influenced by similarity in habitat attributes between native and converted habitats, being greater where there was afforestation (Eucalyptus spp in grassland and savanna). Herbaceous ground cover, soil hardness, and tree richness were the most important habitat attributes that correlated with differences in seed removal. Our results reveal that the magnitude of impact of land‐use changes on seed removal varies depending on native vegetation type and is associated with the type of habitat attribute change. Our findings have implications for biodiversity in tropical grassy systems: afforestation can have a greater detrimental impact on ecological function than tree loss.

Modelling the impacts of agriculture in mixed-use landscapes: a review and case study involving two species of dabbling ducks

This study synthesizes evidence from three separate surveys of American Black Duck and Mallard breeding habitat usage to quantify the effects of agriculture at the landscape scale. To assess duck breeding activity in agricultural landscapes within the Canadian maritimes in order to measure the overall impact of agricultural land use, the response to particular agricultural activities, and the influence of landscape configuration. Models, constructed using a long-term census (SURVEY1), were used to predict habitat selection for two other independent surveys (SURVEY2, SURVEY3). Predictions incorporated information about wetland area and diversity, as well as anthropogenic factors, allowing subsequent analyses to focus on the remaining residual error attributable to agricultural effects. SURVEY2 results demonstrated that the proportion of active agriculture is an important indicator of the severity of human disturbance, yielding threshold estimates of 39% for Mallards and 60% for Black Ducks, with an overall average of 50%. Agricultural conversion beyond these thresholds deterred breeding ducks independently of other factors. SURVEY3 land cover information demonstrated that the presence of cropland intensified this deterrence effect, even at levels as low as 10%. Woodland cover (in excess of 30%) was important for both species, but its configuration was not. In addition to quantifying threshold effects, this study reaffirms that woodland is an important part of the maritime landscape matrix, and contributes positively to habitat diversity in mixed use, moderate intensity agricultural regions. Wetland restoration in agricultural landscapes should monitor and promote less crop-intensive, mixed-use practices.

Flower visitor communities are similar on remnant and reconstructed tallgrass prairies despite forb community differences

One common goal of habitat restoration and reconstruction is to reinstate the biodiversity found at intact reference sites. However, few researchers have examined whether these practices reinstate communities of flower‐visiting insects. This is unfortunate, as anthropogenically mediated declines in flower visitors, including bees (the primary pollinators for most terrestrial ecosystems), beetles, flies, and butterflies, have been reported worldwide. Biodiversity declines may be especially severe in North America's tallgrass prairie, a once‐vast grassland that has experienced severe destruction and degradation due to agricultural conversion. As such, we assessed the structure of forb and flower‐visiting insect communities as a whole and two subsets of the flower visitor community—bees and phytophagous beetles—across five tallgrass prairie remnants and five reconstructed prairies (former crop fields) in Kansas from 2013 to 2015. Remnant prairies had significantly higher forb diversity and differed significantly in forb composition, compared to reconstructed prairies. Despite the dissimilarities in forb community structure, there were no differences in flower visitor diversity or abundance between remnants and reconstructed prairies. However, when considered separately, bee communities exhibited significantly greater variability in composition on reconstructed prairies, likely due to the abundance of generalist bee species visiting non‐native legumes at two reconstructed prairies. Our work provides evidence that prairie habitat reconstruction is a valuable tool for reestablishing flower‐visiting insect communities and also emphasizes the considerable role that non‐native species may play in structuring grassland plant–bee interactions.

Structure and tree species composition in different habitats of savanna used by indigenous people in the Northern Brazilian Amazon.

BackgroundWoody plant diversity from the Amazonian savannas has been poorly quantified. In order to improve the knowledge on wood plants of these regional ecosystems, a tree inventory was carried out in four different habitats used by indigenous people living in the savanna areas of the Northern Brazilian Amazon. The habitats were divided into two types (or groups) of vegetation formations: forest (riparian forest, forest island, and buritizal = Mauritia palm formation) and non-forest (typical savanna). The inventory was carried out in two hectares established in the Darora Indigenous Community region, north of the state of Roraima.New informationThe typical savanna is the most densely populated area (709 stems ha-1); however, it has the lowest tree species richness (nine species, seven families) in relation to typical forest habitats: riparian forest (22 species, 13 families and 202 stems ha-1), forest islands (13 species, 10 families and 264 stems ha-1), and buritizal (19 species, 15 families and 600 stems ha-1). The tree structure (density and dominance) of the forest habitats located in the savanna areas studied in this work is smaller in relation to forest habitats derived from continuous areas of other parts of the Amazon. These environments are derived from Paleoclimatic fragmentation, and are currently affected by the impact of intensive use of natural resources as timberselective logging and some land conversion for agriculture.

Small‐clawed otters (Aonyx cinereus) in Indonesian rice fields: latrine site characteristics and visitation frequency

AbstractLatrine sites, or areas where otters scent‐mark and deposit feces, are a habitat feature that serve an important role in communication for many otter species. The small‐clawed otter (Aonyx cinereus) inhabits both natural and rice field landscapes in Southeast Asia. However, latrine site use by small‐clawed otters in rice field landscapes is largely unknown. Based on a 53‐week field survey and landscape analyses, we investigated latrine site use by small‐clawed otters in rice field landscapes in West Sumatra, Indonesia. Using land use and/or local environmental variables as predictors, we performed generalized linear model analyses to explain the spatial patterns of latrine site occurrence and otter visitation frequency to latrine sites. We determined that small‐clawed otters use some latrine sites repeatedly over time; 10 latrine sites were still in use more than 7 years after their initial discovery. Generalized linear model analyses revealed that an intermediate number of rice field huts was the single most important predictor of latrine site occurrence, whereas distance to the nearest settlement, distance to the river, and mean water depth of the rice field adjacent to the latrine site were important predictors of otter visitation frequency to latrine sites. These results indicate that the latrine site preferences of small‐clawed otters in rice field landscapes are strongly associated with intermediate levels of rice farming activities. Indonesian rice fields are being degraded or disappearing at an accelerated rate because of land conversion and modernization of agriculture. We emphasize an urgent need for design and implementation of otter‐friendly rice farming to conserve small‐clawed otters.

Impact of projected land conversion on water balance of boreal soils in western Newfoundland

AbstractConversion of boreal forest into agricultural land is likely to occur due to the shift of climatic zones and increasing food demand. However, any land conversion will affect the water balance and hence solute fluxes within the soil column and connected ecosystems. Understanding the consequences of land conversion on soil hydrology is essential to support an economically viable agriculture while minimizing its environmental footprint. Hydrological models can simulate these effects based on regionally adjusted climate scenarios. Here, we combined a local climate analysis with hydrological simulations (Hydrus-1D) of boreal soils before and after agricultural conversion. Historical climate analysis showed increasing temperatures and growing degree days while precipitation remains stable. Hydrological simulations revealed lower saturation and higher infiltration rates for unconverted soils, indicating lower runoff and increased infiltration and deep percolation. In contrast, agricultural soils have slower infiltration rates, particularly in the upper horizon. Over the long term, agricultural conversion consequently increases erosion risk and nutrient loss by runoff. This might further progressively limit groundwater recharge, affect hydrological processes and functions and future drought/flood conditions at catchment levels. Hence, conversion of boreal soils demands a primary identification of suitable areas to minimize its impacts.

Technological Approaches to Sustainable Agriculture at a Crossroads: An Agroecological Perspective

Most efforts to improve agricultural production remain focused on practices driven by an intensification agenda and not by an agroecological one. Agroecology transcends the reformist notion of organic agriculture and sustainable intensification proponents who contend that changes can be achieved within the dominant agroindustrial system with minor adjustments or “greening” of the current neoliberal agricultural model. In the technological realm, merely modifying practices to reduce input use is a step in the right direction but does not necessarily lead to the redesign of a more self sufficient and autonomous farming system. A true agroecological technological conversion calls into question monoculture and the dependency on external inputs. Traditional farming systems provide models that promote biodiversity, thrive without agrochemicals, and sustain year-round yields. Conversion of conventional agriculture also requires major social and political changes which are beyond the scope of this paper.

Genetic effects of landscape, habitat preference and demography on three co-occurring turtle species.

Expanding the scope of landscape genetics beyond the level of single species can help to reveal how species traits influence responses to environmental change. Multispecies studies are particularly valuable in highly threatened taxa, such as turtles, in which the impacts of anthropogenic change are strongly influenced by interspecific differences in life history strategies, habitat preferences and mobility. We sampled approximately 1500 individuals of three co-occurring turtle species across a gradient of habitat change (including varying loss of wetlands and agricultural conversion of upland habitats) in the Midwestern USA. We used genetic clustering and multiple regression methods to identify associations between genetic structure and permanent landscape features, past landscape composition and landscape change in each species. Two aquatic generalists (the painted turtle, Chrysemys picta, and the snapping turtle Chelydra serpentina) both exhibited population genetic structure consistent with isolation by distance, modulated by aquatic landscape features. Genetic divergence for the more terrestrial Blanding's turtle (Emydoidea blandingii), on the other hand, was not strongly associated with geographic distance or aquatic features, and Bayesian clustering analysis indicated that many Emydoidea populations were genetically isolated. Despite long generation times, all three species exhibited associations between genetic structure and postsettlement habitat change, indicating that long generation times may not be sufficient to delay genetic drift resulting from recent habitat fragmentation. The concordances in genetic structure observed between aquatic species, as well as isolation in the endangered, long-lived Emydoidea, reinforce the need to consider both landscape composition and demographic factors in assessing differential responses to habitat change in co-occurring species.

Geospatial assessment of bioenergy land use and its impacts on soil erosion in the U.S. Midwest

Agricultural land use change, especially corn expansion since 2000s, has been accelerating to meet the growing bioenergy demand of the United States. This study identifies the environmentally sensitive lands (ESLs) in the U.S. Midwest using the distance-weighted Revised Universal Soil Loss Equation (RUSLE) associated with bioenergy land uses extracted from USDA Cropland Data Layers. The impacts of soil erosion to downstream wetlands and waterbodies in the river basin are counted in the RUSLE with an inverse distance weighting approach. In a GIS-ranking model, the ESLs in 2008 and 2011 (two representative years of corn expansion) are ranked based on their soil erosion severity in crop fields. Under scenarios of bioenergy land use change (corn to grass and grass to corn) on two land types (ESLs and non-ESLs) at three magnitudes (5%, 10% and 15% change), this study assesses the potential environmental impacts of bioenergy land use at a basin level. The ESL distributions and projected trends vary geographically responding to different agricultural conversions. Results support the idea of re-planting native prairie grasses in the identified High and Severe rank ESLs for sustainable bioenergy management in this important agricultural region.

A spatial allocation procedure to model land-use/land-cover changes: Accounting for occurrence and spread processes

Land-use/land-cover (LULC) change models integrate the effects of anthropogenic drivers of landscape change. Spatially explicit LULC change models help at understanding the landscape mosaic that emerges from the interplay between local-scale decisions as well as regional and national policies. These models produce valuable spatially explicit scenarios of LULC change that underpin biodiversity impact and ecosystem services assessments. Most raster-based LULC change models adopt the demand-allocation approach to simulate land transitions (i.e. the transformation of one land-cover type to another for a given spatial unit). In a demand-allocation framework the expert fixes the demand (or quantity of change) and the LULC change model uses a spatial procedure to allocate the change (i.e. to select the cells to be transformed to the target land-cover type). Here, we propose a spatial allocation procedure that builds on the assumption that land transitions occur in two phases: change occurrence and change spreading (or contagion). The allocation procedure uses a sorted queue of cells waiting to undergone change. Three parameters (rate of change occurrence, rate of change spreading and acceleration of change-contagion) control the order of cells order in the queue, and ultimately determine the emergence and extent of patches-of-change. We performed a sensitivity analysis where we show that the relation between both rates (i.e. change occurrence and change spreading) allows patches-of-change expand before other patches arise or vice versa. We provide a simple protocol to implement the allocation procedure as the core of a spatial explicit LULC change model, and we applied this protocol in the development of a new model, called MEDLUC, that intends to replicate the most relevant transitions observed in Mediterranean landscapes: urbanisation, rural abandonment and agriculture conversion. For Catalonia, a region in NE Spain, MEDLUC reproduces the empirical patches-of-change distributions from a 16-year period at two spatial resolutions (1km2 and 1ha). Overall, our allocation procedure performs better than a null model for urbanisation and rural abandonment at both resolutions, while it does worse when modelling agriculture conversion.