High Land-use Intensity Research Articles

Beyond land-use intensity: Assessing future global crop productivity growth under different socioeconomic pathways

Productivity growth is essential to meet the increasing global agricultural demand in the future, driven by the growing world population and income. This study develops a hybrid approach to assess future global crop productivity in a holistic way using different productivity measures and improves the understanding of productivity implications of socioeconomic factors by contrasting different shared socioeconomic pathway assumptions. The results show that the global productivity is likely to continue to grow, whereas the productivity growth varies pronouncedly among different future socioeconomic conditions. The fast growth of total factor and partial factor productivity can be reached when slow population growth and high economic growth entail moderate food demand and low investment risks. In contrast, high population growth and low economic growth could lead to relatively high land-use intensity due to the extreme pressure on agricultural production, however, associated with low total factor productivity growth. The model results indicate that the ratio of the total factor productivity growth to cropland expansion has significant impacts on food prices, with increasing prices when cropland increases faster than productivity, and vice versa. Investing in productivity improvement appears to be an effective means of ensuring food availability and sparing cropland, which can contribute to the achievement of sustainable development goals.

THE POSSIBILITIES OF SUSTAINABLE LAND USE FORMATION IN UKRAINE

The tendencies of the land fund change during the last years are considered. An analysis of a number of normative documents was made to highlight the main problems in modern land use. A number of problems in the sphere of land relations during the period of land reform are listed. The systematic deforestation of protective forest stands, violation of the regime of land use within the boundaries of water protection zones and coastal protective bands is observed. In the article, an acute need to implement measures for the use and protection of lands with a view to meeting the set tasks within the territories, which are subjected to significant anthropogenic load as a result of population accumulation and high intensity of land use is highlighted. The need for comprehensive measures to develop and implement technical solutions for the rationalization of land use and land protection is argued in the article. The evaluation of the distribution of agricultural enterprises by the average area of agricultural and the share of the total area of agricultural land in Ukraine, which they occupy is presented. The dynamics of changes in the areas of agricultural land and arable land in their composition, as well as pastures, hayfields, deposits, and perennial plantations is investigated.

TREND ANALYSIS OF LAND UTILIZATION IN BANGLADESH

Due to alterations in physiographic and social-economic conditions, climatic changes, adaptation and population growth, the land utilization of Bangladesh is changing very rapidly. Small farms and landless household constitute about 80% of total area households, the majority of whom depend on agriculture for their livelihood. It is obvious that total agriculture land over the periods in the past has not increased although population has increased significantly [12]. Bangladesh is a small country but it bears a huge population, resulting in a very high density of population and very high intensity of land and resource use. Based on secondary data of Bangladesh Bureau of Statistics, an attempt has been made in this paper to evaluate the changes in land use pattern during the period of 1990 to 2015. Absolute utilization of land for different purposes during this period as well as trend values and growth rates were estimated. Trend analysis and exponential growth rate showed that forest area significantly increased by 35.93% and 0.3% per annum and land not available for cultivation is significantly decreased by 4.49% and 0.04%per annum respectively. Result also show that cultivate waste is significantly decreased at the rate of 1.1% per annum. On the other hand, a current fallow is decreased by 0.2% per annum. The trend values was found statistically significant for land use in forest and cultivate waste.

High land-use intensity in grasslands constrains wild bee species richness in Europe

There is widespread concern regarding declines in bee populations given their importance for the functioning of both natural and managed ecosystems. An increasing number of studies find negative relations between bee species richness and simplification of agricultural landscapes, but the role of land-use intensity and its relative importance compared to landscape simplification remain less clear. We compared the relative effects of nitrogen inputs, as a proxy for land-use intensity, and proportion of natural and semi-natural habitat, as a measure of landscape complexity on total bee species richness, rare species richness and dominant crop-visiting species richness. We used data from 282 grasslands across five countries, covering the entire range of low intensity, no-input systems, to high-input sites (>400 kg N/ha/year). We found consistent negative impacts of increasing land-use intensity at a regional scale on total bee species richness and dominant crop-visiting species across Europe, but no such effects of landscape complexity. In contrast, the richness of rare bee species was not significantly related to increasing land-use intensity. Nevertheless, based on species accumulation curves, grasslands with no nitrogen inputs had higher total bee richness and higher shares of rare species compared with sites with high nitrogen inputs (>125 kg N/ha/year). Our results highlight the importance of retaining grasslands characterised by low land-use intensity across agricultural landscapes to promote bee diversity.

Abundance of arthropods as food for meadow bird chicks in response to short- and long-term soil wetting in Dutch dairy grasslands.

BackgroundThroughout the world, intensive dairy farming has resulted in grasslands almost devoid of arthropods and birds. Meadow birds appear to be especially vulnerable during the chick-rearing period. So far, studies have focused mainly on describing population declines, but solutions to effectively stop these trends on the short-term are lacking. In this study at a single farm, we experimentally manipulated soil moisture through occasional irrigation, to mitigate against early season drainage and create favorable conditions for the emergence of above-ground arthropods during the meadow bird chick rearing phase.MethodsTo guarantee the presence of at least a sizeable arthropod community for the measurement of effects of wetting, we selected a farm with low intensity management. The land use and intensity of the study site and surroundings were categorized according to the national land use database and quantified using remote sensing imagery. From May 1 to June 18, 2017, we compared a control situation, with no water added, to two wetting treatments, a “short-term” (3 weeks) treatment based on wetting on warm days with a sprinkler system and a “long-term” treatment next to a water pond with a consistently raised water table from 2010. We measured soil temperature, soil moisture and resistance as well as the biomass of arthropods at 3-day intervals. Flying arthropods were sampled by sticky traps and crawling arthropods by pitfall traps. Individual arthropods were identified to Order and their length recorded, to assess their relevance to meadow bird chicks.ResultsThe land use analysis confirmed that the selected dairy farm had very low intensity management. This was different from most of the surrounding area (20 km radius), characterized by (very) high intensity land use. The experiments showed that irrigation contributed to cooler soils during midday, and that his happened already in the early part of the season; the differences with the control increased with time. In the short- and long-term treatments, soil moisture increased and soil resistance decreased from the mid-measurement period onward. Compared with the control, cumulative arthropod biomass was higher in the long-term treatment, but showed no change in the irrigation treatment. We conclude that small-scale interventions, such as occasional irrigation, favorably affected local soil properties. However, the effects on above-ground arthropod abundance currently appear limited or overridden by negative landscape-scale processes on arthropods.

Farms or Forests? Understanding and Mapping Shifting Cultivation Using the Case Study of West Garo Hills, India

Attempts to study shifting cultivation landscapes are fundamentally impeded by the difficulty in mapping and distinguishing shifting cultivation, settled farms and forests. There are foundational challenges in defining shifting cultivation and its constituent land-covers and land-uses, conceptualizing a suitable mapping framework, and identifying consequent methodological specifications. Our objective is to present a rigorous methodological framework and mapping protocol, couple it with extensive fieldwork and use them to undertake a two-season Landsat image analysis to map the forest-agriculture frontier of West Garo Hills district, Meghalaya, in Northeast India. We achieve an overall accuracy of ~80% and find that shifting cultivation is the most extensive land-use, followed by tree plantations and old-growth forest confined to only a few locations. We have also found that commercial plantation extent is positively correlated with shortened fallow periods and high land-use intensities. Our findings are in sharp contrast to various official reports and studies, including from the Forest Survey of India, the Wastelands Atlas of India and state government statistics that show the landscape as primarily forested with only small fractions under shifting cultivation, a consequence of the lack of clear definitions and poor understanding of what constitutes shifting cultivation and forest. Our results call for an attentive revision of India’s official land-use mapping protocols, and have wider significance for remote sensing-based mapping in other shifting cultivation landscapes.

The mineralosphere – Succession and physiology of bacteria and fungi colonising pristine minerals in grassland soils under different land-use intensities

The mineralosphere is an important micro habitat in terrestrial ecosystems. How different groups of microorganisms colonise mineral surfaces and whether the level of grassland land-use intensity (LUI) modifies this micro-habitat is not well known, however. We exposed mesh containers filled with pristine soil minerals (illite/goethite) mixed with 13C labelled root litter of Dactylis glomerata and Lolium perenne in grassland soils of the “Schwäbische Alb” (Germany) to characterise the succession of different microbial properties in the mineralosphere. The use of sites within the Biodiversity Exploratories made it possible to select five sites of low LUI and five sites of high LUI. After 1, 2, 7, 12 and 31 months of exposure in the grassland soils, we used physiological, microbiological and isotopic methods to elucidate in situ colonisation patterns, carbon use and levels of extracellular enzyme expression by soil microorganisms associated with mineral surfaces. Microorganisms slowly colonised pristine mineral surfaces and established functionally distinct communities over time. Fungi colonised mineral surfaces to a greater extent than bacteria, reaching 13.2% of control soils compared to 3.2% by bacteria after 31 months. Fungi also reached pristine mineral surfaces earlier than bacteria, probably due to their hyphal growth strategies, and made immediate use of the added complex root litter substrate. This result is evident by the incorporation of up to 74% root litter-derived C into the fungus-specific PLFA (18:2ω6,9) compared to 51% root litter-derived C in the bacteria-specific PLFAs. Both bacteria and fungi associated with minerals remained in an active state (high biomass-specific respiration, high bacterial and fungal growth rates) throughout the experimental period. Grassland LUI and physico-chemical properties of the adjacent soil modified both quantity and quality of substrates available to soil microorganisms in the mineralosphere. Since 13C incorporation into microbial biomass was greater under low LUI than under high LUI, we conclude that microorganisms in low LUI sites had to rely on the added root material, while the carbon signal in microorganisms in the high LUI sites was diluted by alternative sources resulting from transport of dissolved organic carbon into the mineralosphere.

Will I stay or will I go? Plant species‐specific response and tolerance to high land‐use intensity in temperate grassland ecosystems

AbstractAimIntensification of land use strongly impacts plant communities by causing shifts in taxonomic and functional composition. Mechanisms of land use‐induced biodiversity losses have been described for temperate grasslands, but a quantitative assessment of species‐specific occurrence optima and maximum tolerance (niche breadth) to land‐use intensity (LUI) in Central European grasslands is still lacking.LocationTemperate, managed permanent grasslands in three regions of Germany.MethodsWe combined extensive field work with a null model–randomization approach, defined a “habitat niche” for each plant species based on occurrence and abundance across 150 grassland sites differing in LUI (i.e., amount of fertilizer, mowing/grazing intensity and a compound index of these), and assessed their realized niche breadth (tolerance). Underlying mechanisms driving species’ responses to LUI were assessed by relating plant functional traits, Ellenberg indicator values (EIV), Grime's ecological strategies (CSR) and Briemle utilization numbers.ResultsOut of 151 plant species, 34% responded negatively, whereas 10% responded positively to high LUI. This pattern was mainly driven by species’ response to fertilization and mowing frequency; grazing intensity response was less pronounced. Positively reacting species, displaying broader niches, were associated with competition‐related functional traits, high EIV for nutrient supply and moisture and high mowing tolerance under spatiotemporally variable conditions. Negatively responding species, displaying relatively narrow niches confined to spatiotemporally homogeneous low LUI sites, were associated with a nutrient‐retentive strategy, under nutrient‐poor, base‐rich soil conditions.ConclusionOur analyses of individual species’ reactions clearly demonstrate that species responding negatively to high LUI display little tolerance towards intensive fertilization and mowing, leading to plant diversity loss; whereas grazing partly thwarts these effects by creating new habitat niches and promoting ruderal species. Our approach can be applied to other habitat types and biogeographical regions in order to quantify local specific response or tolerance, adding to existing knowledge about local vegetation dynamics.

Recovery of ecosystem functions after experimental disturbance in 73 grasslands differing in land‐use intensity, plant species richness and community composition

Abstract Drivers of ecosystem stability have been a major topic in ecology for decades. Most studies have focused on the influence of species richness on ecosystem stability and found positive diversity‐stability relationships. However, land use and abiotic factors shape species richness and functional composition of plant communities and may override species richness‐stability relations in managed grasslands. We analysed the relative importance of land‐use intensity (LUI), resident plant species richness and functional composition for recovery of plant communities (plant species richness, plant cover, above‐ and below‐ground biomass) and release of soil nutrients after a severe mechanical disturbance. Experimental sward disturbance was applied to 73 grassland sites along a LUI gradient in three German regions. We considered relative (ln(disturbance/control)) and absolute (disturbance − control) treatment effects. Using structural equation modelling, we disentangled direct effects of LUI and resident species richness on recovery and indirect effects via changes in functional richness. Community‐weighted‐mean traits rarely mattered for recovery or nutrient release, while functional richness especially increased relative recovery of plant communities but also relative release of NO3‐N and NH4‐N. These effects were enhanced by increasing resident plant species richness and decreasing LUI. Next to these indirect influences of LUI and resident plant species richness via functional community composition, grasslands of high compared with grasslands of low resident plant species richness generally showed decreased recovery of plant communities. In grasslands of high LUI, absolute recovery of some aspects of plant communities was decreased. We did not find consistent differences between the relative importance of the different drivers of recovery after the first and the second season. Overall, resident species richness seemed most important for relative recovery and less important for absolute recovery, where direct effects of LUI were more common. Synthesis. The stability of ecosystems in managed grasslands depends on more than species richness. Thus, drivers that directly affect species richness and functional community composition have to be considered when studying the stability of real‐world ecosystems. More specifically, in managed grasslands high resident species richness but also high land‐use intensity (LUI) decreased the stability of ecosystem functions, which was partially buffered by increases in functional richness.

Impact of land use on woody aboveground biomass in Miombo woodlands of western Zambia – comparison of three allometric equations

Globally, the intensification of land use for agriculture, timber and fuel is considered the leading threat to the diversity and biomass of forests and woodlands. To suggest management options, it is important to understand the patterns and drivers of diversity, structure, biomass and carbon stock of woodland vegetation. In this study we used data from three sites in the Miombo woodlands of western Zambia, which are subject to low, medium and high land-use intensity. We sampled 20 plots of 1 000 m² at each of these sites. Woody vegetation was sampled for richness and structure to provide an understanding of the impact of land-use intensity. Woody plant species richness was not affected by land-use intensity. However, an ANOVA revealed that stem diameter at breast height (DBH) was higher at the low land-use intensity (national park) than at medium and high land-use intensities (selective timber harvest, and non-selective harvest for crop fields and timber). We tested three different allometric equations (one global and two regionally adapted) to determine woody aboveground biomass (AGB) and carbon stock at the three sites. The estimated AGB using the regionally adapted allometric equation of Ryan et al. and the global tropical equation of Brown et al. revealed that the AGB for low and high land-use intensity sites were significantly different from each other with the medium land-use intensity site being intermediate. We concluded that DBH and AGB estimations were influenced by the land-use intensity in the Miombo woodlands as suggested by other studies in the tropical forest and woodlands.

Exploring relationships between land use intensity, habitat heterogeneity and biodiversity to identify and monitor areas of High Nature Value farming

Understanding how species richness is distributed across landscapes and which variables may be used as predictors is important for spatially targeting management interventions. This study uses finely resolved data over a large geographical area to explore relationships between land-use intensity, habitat heterogeneity and species richness of multiple taxa. It aims to identify surrogate landscape metrics, valid for a range of taxa, which can be used to map and monitor High Nature Value farmland (HNV).Results show that variation in species richness is distributed along two axes: land-use intensity and habitat heterogeneity. At low intensity land-use, species rich groups include wetland plants, plant habitat indicators, upland birds and rare invertebrates, whilst richness of other species groups (farmland birds, butterflies, bees) was associated with higher land-use intensity. Habitat heterogeneity (broadleaved woodland connectivity, hedgerows, habitat diversity) was positively related to species richness of many taxa, both generalists (plants, butterflies, bees) and specialists (rare birds, woodland birds, plants, butterflies).The results were used to create maps of HNV farmland. The proportion of semi-natural vegetation is a useful metric for identifying HNV type 1. HNV type 2 (defined as a mosaic of low-intensity habitats and structural elements) is more difficult to predict from surrogate variables, due to complex relationships between biodiversity and habitat heterogeneity and inadequacies of current remotely sensed data.This approach, using fine-scaled field survey data collected at regular intervals, in conjunction with remotely sensed data offers potential for extrapolating modelled results nationally, and importantly, can be used to assess change over time.

Urban land use planning within the system of sustainable urban development management

Agricultural and forest lands near settlements are main reserve for expansion of urban areas. Thus, among 148.5 thousand hectares of lands added to Moscow city territory in 2012, 72.2 thousand hectares or 48% were occupied by agricultural and forest lands. Urban areas are characterized by excessively high intensity of land use, land depletion, deterioration in environmental quality and decline in sustainability of urban development. The paper presents the results of analysis of urban land use planning system in the interests of sustainable development of urban territories. The object of the study is the land that is part of Moscow, which is planned to be developed in the coming decades. The authors propose an algorithm for urban development of such areas, which takes into account the quality of land. Design calculations for areas under development were carried out for Shchapovskoye settlement in New Moscow as an example. In addition, the paper covers aspects of land management when developing agricultural land within cities. The authors developed a classification of agricultural land according to a criterion of “suitability for urban development”. The suggested classification has been applied to achieve the objectives of planning urban land use development, determining the order of construction on agricultural lands within the system of sustainable urban development management.

Not all crashes are created equal: Associations between the built environment and disparities in bicycle collisions

Historically disadvantaged populations are disproportionately represented in bicycle crashes. Previous research has found that Black and Hispanic bicyclists and areas with higher populations of non-White residents, lower median income, and high poverty experience bicycle crashes more frequently than others. Although existing research has explored the role of socioeconomic status and the built environment in predicting crash frequency, few scholars have studied how these factors account for disparities along racial and ethnic lines. Using a database of 7,088 bicycle crashes over a three-year period in the San Francisco Bay Area, this study examines the influence of socioeconomic, transportation, and land-use characteristics as potential causes of differences in bicycle crash occurrences among racial and ethnic groups in the San Francisco Bay Area. While areas of high poverty and high land-use intensity are associated with higher numbers of bicycle crashes overall, lower-traffic streets and bicycle infrastructure do not affect the frequency of crashes involving Black and Hispanic cyclists. Black bicyclists have a disproportionate risk of being involved in a crash in poor urban neighborhoods, controlling for other factors. These findings draw attention to the need for planners to consider how socioeconomic differences and vulnerability at the neighborhood level play a role in safety.

Changes in Phylogenetic Community Structure of the Seedling Layer Following Hurricane Disturbance in a Human-Impacted Tropical Forest

Disturbance plays a key role in shaping forest composition and diversity. We used a community phylogeny and long-term forest dynamics data to investigate biotic and abiotic factors shaping tropical forest regeneration following both human and natural disturbance. Specifically, we examined shifts in seedling phylogenetic and functional (i.e., seed mass) community structure over a decade following a major hurricane in a human-impacted forest in Puerto Rico. Phylogenetic relatedness of the seedling community decreased in the first five years post-hurricane and then increased, largely driven by changes in the abundance of a common palm species. Functional structure (based on seed mass) became increasingly clustered through time, due to canopy closure causing small-seeded, light-demanding species to decline in abundance. Seedling neighbor density and phylogenetic relatedness negatively affected seedling survival, which likely acted to reduce phylogenetic relatedness within seedling plots. Across the study site, areas impacted in the past by high-intensity land use had lower or similar phylogenetic relatedness of seedling communities than low-intensity past land use areas, reflecting interactive effects of human and natural disturbance. Our study demonstrates how phylogenetic and functional information offer insights into the role of biotic and abiotic factors structuring forest recovery following disturbance.

Prevalence and genotyping of Trichomonas infections in wild birds in central Germany.

Avian trichomonosis is a widespread disease in columbids and other birds, caused by ingestion of the unicellular flagellate Trichomonas gallinae which proliferate primarily in the upper respiratory tracts. Studies using genetic analyses have determined some highly pathogenic lineages in birds, but the prevalence and distribution of potentially pathogenic and non-pathogenic T. gallinae lineages in wild birds is still not well known. We examined 440 oral swab samples of 35 bird species collected between 2015 and 2017 in Hesse, central Germany, for Trichomonas spp. infection and for determining the genetic lineages. Of these birds, 152 individuals were caught in the wild and 288 individuals were admitted from the wild to a veterinary clinic. The overall Trichomonas spp. prevalence was 35.6%. We observed significant differences between bird orders, with the highest prevalence in owls (58%) and columbids (50%), while other orders had slightly lower prevalences, with 36% in Accipitriformes, 28% in Falconiformes and 28% in Passeriformes. Among 71 successfully sequenced samples, we found 13 different haplotypes, including two previously described common lineages A/B (20 samples) and C/V/N (36 samples). The lineage A/B has been described as pathogenic, causing lesions and mortality in columbids, raptors and finches. This lineage was found in 11 of the 35 species, including columbids (feral pigeon, woodpigeon, stock dove), passerines (greenfinch, chaffinch, blackbird) and raptors (common kestrel, sparrowhawk, red kite, peregrine falcon and common buzzard). One new lineage (R) was found in a sample of a chaffinch. In conclusion, we found that the prevalence of Trichomonas spp. infection in wild birds was high overall, and the potentially pathogenic lineage A/B was widespread. Our findings are worrying, as epidemic outbreaks of trichomonosis have already been observed in Germany in several years and can have severe negative effects on bird populations. This disease may add to the multiple pressures that birds face in areas under high land-use intensity.

Direct and indirect effects of land use on bryophytes in grasslands

Land-use intensification is the major threat for biodiversity in agricultural grasslands, and fertilization has been suggested as the most important driver. A common explanation for the decline of bryophyte diversity with higher land-use intensity is an indirect negative effect via the increase in vascular plant productivity, which reduces light levels for bryophytes. However, direct negative effects of land-use intensification may also be important. Here, we disentangle direct and vascular plant biomass mediated indirect effects of land use on bryophytes. We analyzed two complementary datasets from agricultural grasslands, an observational study across 144 differently managed grasslands in Germany and an experimental fertilization and irrigation study of eleven grasslands in the Swiss Alps. We found that bryophyte richness and cover strongly declined with land-use intensity and in particular with fertilization. However, structural equation modelling revealed that although both direct and indirect effects were important, the direct negative effect of fertilization was even stronger than the indirect effect mediated by increased plant biomass. Thus, our results challenge the widespread view that the negative effects of fertilization are mostly indirect and mediated via increased light competition with vascular plants. Our study shows that land use intensification reduces bryophyte diversity through several different mechanisms. Therefore, only low-intensity management with limited fertilizer inputs will allow the maintenance of bryophyte-rich grasslands.

Structural and functional characteristics of buffer strip vegetation in an agricultural landscape – high potential for nutrient removal but low potential for plant biodiversity

Vegetated buffer strips constitute a transition zone between terrestrial and aquatic ecosystems and provide several ecosystem services. Buffer strips are often applied as a mitigation measure against diffuse pollution in agricultural areas, primarily because they may retain nutrients and in this way help protect the aquatic environment. Additionally, they can improve biodiversity in an otherwise homogenous landscape and may therefore have a value in their own right. In the present study, we characterized the structural and functional features of the vegetation in Danish buffer strips using a nationwide dataset to explore: i) their floristic quality in terms of species diversity and conservation value and ii) based on their functional characteristics, their potential to retain nutrients. Moreover, we analyzed how the structural and functional characteristics varied along gradients in the environmental features of the catchment. We found that the floristic quality of the buffer vegetation was generally low, exhibiting an average of only 3.3% of the number of species of conservation interest. Instead, Danish buffer strips were dominated by widespread and productive species that are tolerant of anthropogenic impacts in the catchment. The abundance of highly productive plant species was positively related to high intensity land use, whereas the abundance of stress-tolerant plant species was positively related to low intensity land use. The high productivity of the buffer strips implies a large bio-storage potential, and these areas might therefore offer an opportunity to remove nutrients by harvesting the plant biomass. We discuss how Danish buffer strips could be exploited via appropriate management (e.g. harvesting) to maximize nutrient retention and at the same time improve floristic quality.

High land-use intensity exacerbates shifts in grassland vegetation composition after severe experimental drought.

Climate change projections anticipate increased frequency and intensity of drought stress, but grassland responses to severe droughts and their potential to recover are poorly understood. In many grasslands, high land-use intensity has enhanced productivity and promoted resource-acquisitive species at the expense of resource-conservative ones. Such changes in plant functional composition could affect the resistance to drought and the recovery after drought of grassland ecosystems with consequences for feed productivity resilience and environmental stewardship. In a 12-site precipitation exclusion experiment in upland grassland ecosystems across Switzerland, we imposed severe edaphic drought in plots under rainout shelters and compared them with plots under ambient conditions. We used soil water potentials to scale drought stress across sites. Impacts of precipitation exclusion and drought legacy effects were examined along a gradient of land-use intensity to determine how grasslands resisted to, and recovered after drought. In the year of precipitation exclusion, aboveground net primary productivity (ANPP) in plots under rainout shelters was -15% to -56% lower than in control plots. Drought effects on ANPP increased with drought severity, specified as duration of topsoil water potential ψ<-100kPa, irrespective of land-use intensity. In the year after drought, ANPP had completely recovered, but total species diversity had declined by -10%. Perennial species showed elevated mortality, but species richness of annuals showed a small increase due to enhanced recruitment. In general, the more resource-acquisitive grasses increased at the expense of the deeper-rooted forbs after drought, suggesting that community reorganization was driven by competition rather than plant mortality. The negative effects of precipitation exclusion on forbs increased with land-use intensity. Our study suggests a synergistic impact of land-use intensification and climate change on grassland vegetation composition, and implies that biomass recovery after drought may occur at the expense of biodiversity maintenance.

Simulating incomes of radical organic farms with MERLIN: A grounded modeling approach for French microfarms

Microfarms are commercial soil-based market gardens with <1.5ha of organic vegetables per farmer seeking to make a living on that small acreage by combing high land-use intensity, low input and few mechanized practices with direct sells. Insights in their profitability are missing in literature. Our research objective was to build a simulation model of micro-farms' income and agricultural area based on farmers' expertise. An interactive development based on grounded modelling was implemented. This implied an inductive qualitative analysis and farmers' participation to collect data and to build and validate the model. With data collected on 20 micro-farms', a stochastic simulation model (MERLIN) was built, combining (i) two mixed models to predict yields and workload for 50 crops, and (ii) a crop-planning model. MERLIN generates cropping plans that match the complex and temporal commercial requirements for direct selling of vegetable boxes through community-supported agricultural schemes. The model was validated with various strategic choices, climate assumptions and annual workload. Our model was judged relevant and legitimate by agricultural practitioners because it was not prescriptive and corresponds to strategic preferences of organic farmers. Grounded modelling is promising to create generic knowledge adapted to radical organic farming systems, but some epistemological implications require further investigation, e.g. by taking benefit from the transdisciplinary framework developed in agroecological studies.

Changes of Agricultural Land Uses in Rural Area and Causes Behind It: A Case Study of Kamargaon Union Under Tanore Upazila in Rajshahi District

Rajshahi District is a very high density of population and very high intensity of land use. In Rajshahi District per capita land is estimated to be only about 0.0526 ha. The Population growth rate is also high. For the high growth rate of population requires huge land for settlement and with the increase of population the demand of food also increases. For meeting the increasing food demand the land is using very intensively of this District. Every year the district is losing 0.47% arable land due to the population growth and its infrastructure development. This study was conducted on Tanore Upazila where the major focus was to see the changes of Rural Agricultural land uses and the causes of agricultural land use changes. For analyses both primary data and secondary data were collected. Primary data were collected by applying PRA techniques and secondary data were collected from published and unpublished data regarding crop, population and other sources. Results show that huge change in rural agricultural land uses take place in the study area and find some important causes of agricultural land use changes in rural area. Infrastructural development is the main causes of agricultural land losses. If proper steps would not be taken it creates great problems in near future.