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Arable Land (arable + land)
Kinds of Arable Land Selected AbstractsModelling land use changes and their impact on soil erosion and sediment supply to riversEARTH SURFACE PROCESSES AND LANDFORMS, Issue 5 2002Anton J. J. Van Rompaey Abstract The potential for surface runoff and soil erosion is strongly affected by land use and cultivation. Therefore the modelling of land use changes is important with respect to the prediction of soil degradation and its on-site and off-site consequences. Land use changes during the past 250 years in the Dijle catchment (central Belgium) were analysed by comparing four historical topographic maps (1774, 1840, 1930 and 1990). A combination of land use transformation maps and biophysical land properties shows that certain decision rules are used for the conversion of forest into arable land or vice versa. During periods of increasing pressure on the land, forests were cleared mainly on areas with low slope gradients and favourable soil conditions, while in times of decreasing pressure land units with steep and unfavourable soil conditions were taken out of production. Possible future land use patterns were generated using stochastic simulations based on land use transformation probabilities. The outcome of these simulations was used to assess the soil erosion risk under different scenarios. The results indicate that even a relatively limited land use change, from forest to arable land or vice versa, has a significant effect on regional soil erosion rates and sediment supply to rivers. Copyright © 2002 John Wiley & Sons, Ltd. [source] Response of collembolan communities to land-use change and grassland successionECOGRAPHY, Issue 2 2007Matthieu Chauvat This study focuses on the long-term changes of collembolan communities occurring after the conversion of arable land to managed grassland. We analysed collembolan communities at grassland sites of different age that had been gradually converted over a period of 50 yr. Abundance and biomass responded rapidly and very positively to the conversion of arable land to grassland, while species richness was not affected. Collembolan assemblages changed only little during grassland maturation. The impact of land-use change on community structure was more obvious at the functional level because the colonization processes observed in our study mostly relied on hemiedaphic species. Vegetation and soil parameters were good predictors of collembolan community structure during development of managed grassland. The present study demonstrated that past landscape patterns and processes like land-use conversion and subsequent succession had a considerable impact on the present day pattern of species richness and community composition of Collembola within a landscape. Our results strongly differ from those obtained for other invertebrate groups, highlighting on the one hand the very diverse reactions of invertebrates to a common factor, and on the other hand the need to survey more than one taxa in order to draw conclusions on effects of land-use change on faunistic communities. [source] Subsistence and sales: the peasant economy of Württemberg in the early seventeenth centuryECONOMIC HISTORY REVIEW, Issue 2 2006PAUL WARDE This article examines the engagement of peasant cultivators with the grain market in Germany in the seventeenth century. It demonstrates a differentiated propensity to sell in regard to different grains; a preference among cultivators for retaining subsistence foodstuffs; the importance of payment in kind in the labour market; and the lack of a clear-cut social structural divide between grain sellers and buyers among those who cultivate arable land. It is thus argued that the analytical concept of ,the peasant' retains its use in understanding this society, but that attitudes displayed by the peasantry to ,the market' must be clearly set in the context of the specific product markets and practices to retain any analytical value. [source] Risk assessment of herbicide mixtures in a large European lakeENVIRONMENTAL TOXICOLOGY, Issue 2 2008Nathalie Chèvre Abstract Lake Geneva is one of the largest European lakes with a surface area of 580 km2. Its catchment area covers 7400 km2, of which ,20% is arable land. Monitoring campaigns have been carried out in 2004 and 2005 to determine the contamination of the lake by pesticides. The results highlight the widespread presence of herbicides in water, the measured concentrations for most substances remaining constant in 2004 and 2005. However, for some individual herbicides the concentrations increased drastically (e.g., the herbicide foramsulfuron). We assessed the environmental risk of the herbicides detected in the lake using water quality criteria recently determined for the Swiss environmental protection agency. Furthermore, we assessed the risk of herbicide mixtures, grouped based upon their mode of action. Generally, the risk estimated for all single substances is low, except for some sulfonylurea compounds. For these substances, the measured concentrations are higher than the predicted no-effect concentration. Impact on the flora of the lake can therefore not be excluded. When mixtures of pesticides with similar mode of action are taken into account, the risk remains lower than the mixture water quality criteria for all groups, but can reach as high as one third of this quality criteria. A further step would therefore be to assess the risk of the total pesticide mixture, including similar and dissimilar modes of action. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008. [source] Single- and two-species tests to study effects of the anthelmintics ivermectin and morantel and the coccidiostatic monensin on soil invertebratesENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 2 2009John Jensen Abstract Soil invertebrates in arable land are potentially exposed to veterinary medicines excreted by husbandry. The toxicity of three widely used pharmaceuticals was therefore investigated with the use of common soil invertebrates exposed in the laboratory in single- or two-species test system. The anthelmintic morantel did not cause significant mortality to either Folsomia fimetaria or Enchytraeus crypticus even at the highest tested concentration of 900 mg kg,1 dry soil. The coccidiostatic monensin affected the reproduction of F. fimetaria and E. crypticus with soil concentrations estimated to cause a 10% effect at values of approximately 109 and 71.8 mg kg,1 dry soil, respectively, but caused no mortality to adult. The anthelmintic ivermectin did not affect the survival of adult Hypoaspis aculeifer. Reproduction of H. aculeifer declined approximately 45% in response to ivermectin exposure of 5 mg kg,1 dry soil. Ivermectin was highly toxic to F. fimetaria and affected the survival of adults with soil concentrations estimated to cause a 50% mortality at values of 5.3 mg kg,1 dry soil in the single-species test system and 0.14 mg kg,1 dry soil in the two-species test system. Reproduction of F. fimetaria was reduced by ivermectin with 10% effective concentration at 0.19 mg kg,1 dry soil in the single-species test system and 0.02 mg kg,1 dry soil in two-species test system. It was shown that species interactions may influence the response of test organisms to toxic substances. The data from this study and previously published data showed that, whereas ivermectin is likely to pose a risk to soil-dwelling invertebrates, adverse effects of morantel and monensin are unlikely to occur as a result of residue excretion from treated farm animals. [source] Agricultural and Rural Development in China: Achievements and Challenges Entwicklung der Landwirtschaft und des ländlichen Raums in China: Erfolge und Herausforderungen Le développement agricole et rural en Chine : résultats et défisEUROCHOICES, Issue 2 2009Chen Xiaohua Summary Agricultural and Rural Development in China: Achievements and Challenges China has made great advances in its agricultural and rural development since the reforms and opening-up that began in 1978. It has not only fed its population of 1.3 billion, but has also contributed to international agricultural development and food security. Agricultural production registered great development, providing sufficient food and clothes for 21 per cent of the world's population with 9 per cent of the arable land. In the process farmers' living standards improved remarkably and rural public utilities and services were greatly enhanced. China is now in a key transition period of accelerating the transformation and modernisation of traditional agriculture and rural society. It is facing significant challenges. Agriculture is still one of the weakest industries in China and it is proving difficult to sustain increases in grain output and farmers' incomes. The problems of uneven development in rural areas have become increasingly prominent and the gap between urban and rural development is tending to widen. The Chinese government will respond strategically to these challenges and will firmly pursue the construction of a new efficient and sustainable socialist countryside, along the path of modernisation with Chinese characteristics. It will also make greater contributions to world agriculture and rural development. Les progrès de la Chine en termes de développement agricole et rural depuis le début des réformes et l'ouverture en 1978 ont été considérables. Non seulement le pays a nourrit une population de 1.3 millions d'habitants mais il a contribué au développement et à la sécurité alimentaire au niveau international. La production agricole a fortement augmenté et a fournit suffisamment de nourriture et de vêtements à 21 pour cent de la population du monde avec 9 pour cent des terres cultivables. Ce processus s'est accompagné d'une hausse considérable du niveau de vie des agriculteurs et d'une grande amélioration des services publics dans les zones rurales. La Chine est maintenant à un moment clé de sa période de transition, caractérisé par une accélération de la transformation et de la modernisation de l'agriculture et de la société rurale traditionnelles. Des défis importants se présentent à elle. L'agriculture reste une des industries chinoises les plus fragiles et il se révèle difficile de continuer à augmenter la production céréalière et les revenus des agriculteurs. Les problèmes d'inégalité de développement dans les zones rurales deviennent de plus en plus visibles et l'écart de développement entre les zones urbaines et les zones rurale tend à s'accroître. Les pouvoirs publics chinois vont apporter une réponse stratégique à ces défis et vont poursuivre fermement la construction d'une nouvelle campagne socialiste efficace et durable, en suivant une voie de modernisation typiquement chinoise. Ils vont aussi accroître les contributions de la Chine au développement agricole et rural mondial. Seit Beginn der Reformen und der Öffnungspolitik 1978 hat sich Chinas Landwirtschaft und ländlicher Raum enorm weiterentwickelt. China hat seitdem nicht nur seine 1.3 Milliarden Einwohner ernährt, sondern auch zur internationalen Agrarentwicklung und Ernährungssicherung beigetragen. Die Agrarproduktion wurde erheblich ausgeweitet und deckt nun 21 Prozent des weltweiten Bedarfs an Lebensmitteln und Kleidung bei gerade einmal 9 Prozent der Weltackerfläche. Dabei haben sich die Lebensbedingungen für die Landwirte sowie das Angebot an öffentlichen Einrichtungen und Dienstleistungen im ländlichen Raum deutlich verbessert. China durchläuft gerade eine wichtige Übergangsphase, in der sich der Wandel und die Modernisierung der traditionellen Landwirtschaft und der Landbevölkerung noch schneller vollziehen, und steht großen Herausforderungen gegenüber. Die Landwirtschaft ist nach wie vor einer der schwächsten Sektoren in China, und es erweist sich als schwierig, die Steigerungsraten bei der Getreideerzeugung und den Einkommen in der Landwirtschaft aufrecht zu erhalten. Die Probleme der ungleichmäßigen Entwicklung in ländlichen Gebieten werden immer offensichtlicher, und die Kluft zwischen städtischer und ländlicher Entwicklung droht sich auszuweiten. Die chinesische Regierung wird diesen Herausforderungen strategisch begegnen und , ganz im Sinne einer Modernisierung mit chinesischen Merkmalen , daran festhalten, einen neuen sozialistischen ländlichen Raum effizient und nachhaltig zu gestalten. Sie wird ebenfalls einen noch größeren Beitrag zur Weltlandwirtschaft und zur Entwicklung des ländlichen Raums leisten. [source] Fate of airborne metal pollution in soils as related to agricultural management.EUROPEAN JOURNAL OF SOIL SCIENCE, Issue 3 2007Summary The fate of airborne metal pollutants in soils is still relatively unknown. We studied the incorporation of such airborne metal pollution in two soils under long-term permanent pasture (PP) and conventional arable land (CA). Both soils were located at an almost equal distance from a former zinc smelter complex and developed under comparable pedogenetic conditions. Profiles of total concentrations of Zn, chosen as a mobile, and Pb as a little- or non-mobile element, were examined and compared with macro- and micromorphological soil characteristics (soil colour, biological activity). The two soils showed different profiles of total Zn and Pb concentrations, with a marked decrease of concentrations of both elements under the plough layer in CA, whereas the decrease was more progressive in PP. However, the stocks of Zn and Pb for the 1-m soil profiles of CA and PP were comparable. Correlation of Zn and Pb concentration at different depths with total Fe contents and comparison with estimated data for the local geochemical background (LGCB), suggests transport of Zn from the surface to depth in CA and PP, and Pb movement in PP. In CA, 53% of Zn and 92.5% of Pb stocks derived from airborne metal pollution were located at depths < 26 cm. In PP, only 40% of Zn and 82% of Pb, derived from airborne pollution, were found in the A11 and A12 horizons (< 26 cm), the remaining 18% of the Pb stock being incorporated until 50 cm depth; one-third of total Zn stock ascribed to airborne pollution was found at depths > 50 cm. Studies of the composition of gravitational water collected in soils from the same study area suggest two mechanisms for metal movement. First, mobile metal ions (Zn2+) move in the soil solution and are intercepted by iron-clay complexes in deeper soil horizons. Second, observed only in PP, simultaneous movement of Zn and Pb is ascribed to bioturbation by earthworms. [source] Composition of organic matter in a subtropical Acrisol as influenced by land use, cropping and N fertilization, assessed by CPMAS 13C NMR spectroscopyEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 6 2005J. Dieckow Summary We know much about the influence of management on stocks of organic matter in subtropical soils, yet little about the influence on the chemical composition. We therefore studied by CPMAS 13C NMR spectroscopy the composition of the above-ground plant tissue, of the organic matter of the whole soil and of silt- and clay-size fractions of the topsoil and subsoil of a subtropical Acrisol under grass and arable crops. Soil samples were collected from three no-till cropping systems (bare soil; oats,maize; pigeon pea + maize), each receiving 0 and 180 kg N ha,1 year,1, in a long-term field experiment. Soil under the original native grass was also sampled. The kind of arable crops and grass affected the composition of the particulate organic matter. There were no differences in the composition of the organic matter in silt- and clay-size fractions, or of the whole soil, among the arable systems. Changes were observed between land use: the soil of the grassland had larger alkyl and smaller aromatic C contents than did the arable soil. The small size fractions contain microbial products, and we think that the compositional difference in silt- and clay-size fractions between grassland and the arable land was induced by changes in the soil's microbial community and therefore in the quality of its biochemical products. The application of N did not affect the composition of the above-ground plant tissue nor of the particulate organic matter and silt-size fractions, but it did increase the alkyl C content in the clay-size fraction. In the subsoil, the silt-size fraction of all treatments contained large contents of aromatic C. Microscopic investigation confirmed that this derived from particles of charred material. The composition of organic matter in this soil is affected by land use, but not by variations in the arable crops grown. [source] Wavelet analysis of the scale- and location-dependent correlation of modelled and measured nitrous oxide emissions from soilEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 1 2005A. E. Milne Summary We used the wavelet transform to quantify the performance of models that predict the rate of emission of nitrous oxide (N2O) from soil. Emissions of N2O and other soil variables that influence emissions were measured on soil cores collected at 256 locations across arable land in Bedfordshire, England. Rate-limiting models of N2O emissions were constructed and fitted to the data by functional analysis. These models were then evaluated by wavelet variance and wavelet correlations, estimated from coefficients of the adapted maximal overlap discrete wavelet transform (AMODWT), of the fitted and measured emission rates. We estimated wavelet variances to assess whether the partition of the variance of modelled rates of N2O emission between scales reflected that of the data. Where the relative distribution of variance in the model is more skewed to coarser scales than is the case for the observation, for example, this indicates that the model predictions are too smooth spatially, and fail adequately to represent some of the variation at finer scales. Scale-dependent wavelet correlations between model and data were used to quantify the model performance at each scale, and in several cases to determine the scale at which the model description of the data broke down. We detected significant changes in correlation between modelled and predicted emissions at each spatial scale, showing that, at some scales, model performance was not uniform in space. This suggested that the influence of a soil variable on N2O emissions, important in one region but not in another, had been omitted from the model or modelled poorly. Change points usually occurred at field boundaries or where soil textural class changed. We show that wavelet analysis can be used to quantify aspects of model performance that other methods cannot. By evaluating model behaviour at several scales and positions wavelet analysis helps us to determine whether a model is suitable for a particular purpose. [source] Factors influencing the spatial distribution of zooplankton and fish in Loch Ness, UKFRESHWATER BIOLOGY, Issue 4 2000D. G. George Summary 1The vertical and horizontal distribution of phytoplankton, zooplankton and fish in Loch Ness, Scotland, were monitored during one day-time and one night-time survey in July 1992. The vertical samples were collected at a site located at the northern end of the loch and the horizontal samples along a longitudinal transect. 2The vertical distribution surveys demonstrated that the phytoplankton, the zooplankton and the fish were concentrated in the top 30 m of water above the seasonal thermocline. Within this layer, Cyclops stayed much closer to the surface than Eudiaptomus but both species moved towards the surface at night. 3The most important factor influencing the horizontal distribution of the phytoplankton was the north- south gradient in productivity. The sub-catchments surrounding the north basin contain a greater proportion of arable land than those to the south and the concentrations of nitrate-nitrogen and phytoplankton chlorophyll increased systematically from south to north. 4Zooplankton distribution patterns were influenced by wind-induced water movements and the dispersion of allochthonous material from the main inflows. The highest concentrations of Cyclops were recorded in the north, where there was more phytoplankton, and the highest concentrations of Eudiaptomus in the south, where there were higher concentrations of non-algal particulates. 5There was no spatial correlation between total zooplankton and total fish abundance but the highest concentrations of small (1,5 cm) fish were recorded in the south where there was a large patch of Eudiaptomus. The number of Eudiaptomus at specific locations within this patch were, however, negatively correlated with the numbers of small fish. These results suggest that the fish were actively foraging within the patch and were depleting their zooplankton prey in the areas where they were most abundant. [source] Carbon sequestration under Miscanthus: a study of 13C distribution in soil aggregatesGCB BIOENERGY, Issue 5 2009MARTA DONDINI Abstract The growing of bioenergy crops has been widely suggested as a key strategy in mitigating anthropogenic CO2 emissions. However, the full mitigation potential of these crops cannot be assessed without taking into account their effect on soil carbon (C) dynamics. Therefore, we analyzed the C dynamics through four soil depths under a 14-year-old Miscanthus plantation, established on former arable land. An adjacent arable field was used as a reference site. Combining soil organic matter (SOM) fractionation with 13C natural abundance analyses, we were able to trace the fate of Miscanthus -derived C in various physically protected soil fractions. Integrated through the whole soil profile, the total amount of soil organic carbon (SOC) was higher under Miscanthus than under arable crop, this difference was largely due to the input of new C. The C stock of the macroaggregates (M) under Miscanthus was significantly higher than those in the arable land. Additionally, the C content of the micro-within macroaggregates (mM) were higher in the Miscanthus soil as compared with the arable soil. Analysis of the intramicroaggregates particulate organic matter (POM) suggested that the increase C storage in mM under Miscanthus was caused by a decrease in disturbance of M. Thus, the difference in C content between the two land use systems is largely caused by soil C storage in physically protected SOM fractions. We conclude that when Miscanthus is planted on former arable land, the resulting increase in soil C storage contributes considerably to its CO2 mitigation potential. [source] The management of arable land from prehistory to the present: Case studies from the Northern Isles of ScotlandGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 1 2006Erika B. Guttmann The arable soils from two multiperiod settlements were analyzed to identify changes in agricultural methods over time. The settlement middens were also analyzed to determine whether potential fertilizers were discarded unused. Results suggest that in the Neolithic period (,4000,2000 B.C. in the UK) the arable soils at Tofts Ness, Orkney, and Old Scatness, Shetland, were created by flattening and cultivating the settlements' midden heaps in situ. The arable area at Tofts Ness was expanded in the Bronze Age (,2000,700 B.C. in the UK), and the new land was improved by the addition of ash, nightsoil, and domestic waste. Cultivation continued briefly after the fields were buried in windblown sand in the Late Bronze Age or Early Iron Age, but by the Early Iron Age cultivation ceased and organic-rich material was allowed to accumulate within the settlement. By contrast, at Old Scatness, arable production was increased in the Iron Age (,700 B.C.,A.D. 550 in Scotland) by the intensive use of animal manures. The results indicate that during the lifespan of the two settlements the arable soils were fertilized to increase production, which was intensified over time. © 2006 Wiley Periodicals, Inc. [source] Nitrate leaching from three afforestation chronosequences on former arable land in DenmarkGLOBAL CHANGE BIOLOGY, Issue 6 2007KARIN HANSEN Abstract In regions dominated by agricultural activities, nitrogen (N) is recognized as a major pollutant in aquatic environments. In north-western Europe, afforestation of agricultural land is part of a strategy to improve water quality. In Denmark, former arable land has been afforested during the past 40,50 years. This study evaluated the effect of afforestation of former arable land on nitrate leaching, based on three afforestation chronosequences. Precipitation, canopy throughfall and soil water were collected and soil moisture was monitored at two Danish locations, Vestskoven (nutrient-rich, medium deposition) and Gejlvang (nutrient-poor, high deposition). Afforestation was performed using Norway spruce [Picea abies (Karst.) L.] and common oak (Quercus robur L.) at Vestskoven and Norway spruce at Gejlvang. The results suggest that afforestation of former arable land initially leads to lower nitrate leaching than that occurring under the former agricultural land use, and largely below the standard of 50 mg NO,3 L,1 for groundwater to be utilized as drinking water. Nitrate concentrations became almost negligible in forest stands of 5,20 years of age. However, after canopy closure (>20 years) nitrate concentrations below the root zone and nitrate leaching tended to increase. This was attributed to increased N deposition with increasing canopy development and decreased N demand once the most N-rich biomass compartments had been built up. Nitrate leaching started to increase at a throughfall deposition level of about 10 kg N ha,1 yr,1. Compared with nutrient-poor sandy soils, nutrient-rich clayey soils appeared more vulnerable to disturbance of the N cycle and to increased N deposition, leading to N saturation and enhanced nitrate leaching. In approximately the first 35 years after afforestation, nitrate leaching below the root zone was generally higher below oak than below Norway spruce. [source] Carbon emission and sequestration by agricultural land use: a model study for EuropeGLOBAL CHANGE BIOLOGY, Issue 6 2002L. M. Vleeshouwers Abstract A model was developed to calculate carbon fluxes from agricultural soils. The model includes the effects of crop (species, yield and rotation), climate (temperature, rainfall and evapotranspiration) and soil (carbon content and water retention capacity) on the carbon budget of agricultural land. The changes in quality of crop residues and organic material as a result of changes in CO2 concentration and changed management were not considered in this model. The model was parameterized for several arable crops and grassland. Data from agricultural, meteorological, soil, and land use databases were input to the model, and the model was used to evaluate the effects of different carbon dioxide mitigation measures on soil organic carbon in agricultural areas in Europe. Average carbon fluxes under the business as usual scenario in the 2008,2012 commitment period were estimated at 0.52 tC ha,1 y,1 in grassland and ,0.84 tC ha,1 y,1 in arable land. Conversion of arable land to grassland yielded a flux of 1.44 tC ha,1 y,1. Farm management related activities aiming at carbon sequestration ranged from 0.15 tC ha,1 y,1 for the incorporating of straw to 1.50 tC ha,1 y,1 for the application of farmyard manure. Reduced tillage yields a positive flux of 0.25 tC ha,1 y,1. The indirect effect associated with climate was an order of magnitude lower. A temperature rise of 1 °C resulted in a ,0.05 tC ha,1 y,1 change whereas the rising CO2 concentrations gave a 0.01 tC ha,1 y,1 change. Estimates are rendered on a 0.5 × 0.5° grid for the commitment period 2008,2012. The study reveals considerable regional differences in the effectiveness of carbon dioxide abatement measures, resulting from the interaction between crop, soil and climate. Besides, there are substantial differences between the spatial patterns of carbon fluxes that result from different measures. [source] Assessing the effects of hydromorphological degradation on macroinvertebrate indicators in rivers: examples, constraints, and outlookINTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT, Issue 1 2009Nikolai Friberg Abstract An extensive amount of literature on linkages between the in-stream physical environment and river benthic macroinvertebrates reports a number of relationships across multiple spatial scales. We analyzed data on different spatial scales to elucidate the linkages between different measurements of hydromorphological degradation and commonly used macroinvertebrate indices. A regression analysis of 1049 sites from 3 countries revealed that the strongest relationship between a biotic metric,average score per taxon,and physiochemical variables (R2 = 0.61) was obtained with a multiple regression model that included concentration of total phosphorus and percent arable land in the catchment, as well as hydromorphological quality variables. Analyses of 3 data sets from streams primarily affected by hydromorphological degradation showed an overall weak relationship (max R2 = 0.25) with the River Habitat Survey data of 28 Swedish streams, whereas moderate (R2 , 0.43) relationships with more detailed measurements of morphology were found in 2 Danish studies (39 and 6 streams, respectively). Although evidence exists in the literature on the importance of physical features for in-stream biota in general and macroinvertebrates specifically, we found only relatively weak relationships between various measures of hydromorphological stress and commonly used macroinvertebrate assessment tools. We attribute this to a combination of factors, including 1) the mixed nature of pressures acting on the majority of river reaches, 2) scaling issues (spatial and temporal) when relating habitat surveys to macroinvertebrate assessments, and 3) the scope of commonly used macroinvertebrate assessment systems (mainly focusing on water chemistry perturbation, such as eutrophication and acidification). The need is urgent to develop refined and updated biological assessment systems targeting hydromorphological stress for the use of the European Water Framework Directive (WFD) and national water-related policies. [source] Restoration of species-rich grassland on arable land: assessing the limiting processes using a multi-site experimentJOURNAL OF APPLIED ECOLOGY, Issue 2 2002Richard F. Pywell Summary 1Agricultural intensification has resulted in the reduction and fragmentation of species-rich grasslands across much of western Europe. 2We examined the key ecological processes that limit the creation of diverse grassland communities on ex-arable land in a multi-site experiment over a wide variety of soil types and locations throughout lowland Britain. 3The results showed it was possible to create and maintain these communities successfully under a hay-cutting and grazing management regime. Furthermore, there was a high degree of repeatability of the treatment effects across the sites. 4Lack of seed of desirable species was the key factor limiting the assembly of diverse grassland communities. Sowing a species-rich seed mixture of ecologically adapted grassland plants was an effective means of overcoming this limitation. Community assembly by natural colonization from the seed bank and seed rain was a slow and unreliable process. However, there was no evidence to suggest that sowing a species-poor grass-dominated seed mixture made the vegetation any less susceptible to colonization by desirable species than allowing natural regeneration to take place. 5Deep cultivation caused significant reductions in soil P and K concentrations across the sites. This had a significant beneficial effect on the establishment and persistence of sown forbs in all years. It also resulted in a significant reduction in the number of unsown weedy grasses. However, for both variables these differences were very small after 4 years. 6Sowing a nurse crop significantly reduced the number of unsown grass species, but had no beneficial effect on the establishment of desirable species. 7Treatments sown with the species-rich seed mixture following deep cultivation corresponded most closely to the specified target communities defined by the UK National Vegetation Classification. Natural regeneration and treatments sown with the species-poor seed mixture were much less similar to the target. The sites on circum-neutral soils achieved the greatest degree of similarity to the target. Those on calcareous and acid soils failed to achieve their targets and most closely resembled the target for neutral soils. This reflected the poor performance of the sown preferential species for these communities. [source] Abandonment of farmland and vegetation succession following the Eurasian plague pandemic of ad 1347,52JOURNAL OF BIOGEOGRAPHY, Issue 4 2007Dan Yeloff Abstract Aim, This paper reviews the available documentary, archaeological and palaeoecological evidence for the abandonment of agricultural land and consequent regeneration of the forest in Europe after the Black Death. Location, Western and northern Europe. Methods, This review is the result of an exhaustive search of the historical, archaeological and palaeoecological literature for evidence indicating agricultural decline and forest regeneration in Eurasia during the 14th century. The available evidence for landscape change can be divided into two categories: (1) documentary and archaeological sources, and (2) palaeoecological reconstructions of past vegetation. In the past few years, several pollen diagrams from north-west Europe have been reported with precise chronologies (decadal and even annual scale) showing the abandonment of farmland and consequent ecological change in the late medieval period. Results and main conclusions, There is strong evidence of agricultural continuity at several sites in Western Europe at the time of the Black Death. The effects of the Black Death on the European rural landscape varied geographically, with major factors probably including the impact of the plague on the local population, and soil quality. At two sites in western and northern Ireland, the late medieval decline in cereal agriculture was probably a direct result of population reduction following the Black Death. In contrast, the decline in cereal production began at sites in Britain and France before the Black Death pandemic of ad 1347,52, and was probably due to the crisis in the agricultural economy, exacerbated by political instability and climate deterioration. Much of the abandoned arable land was probably exploited for grazing during the period between the decline in cereal farming and the Black Death. In the aftermath of the Black Death, grazing pressure was greatly reduced owing to reductions in the grazing animal population and a shortage of farmers. Vegetation succession on the abandoned grazing land resulted in increased cover of woody tree species, particularly Betula and Corylus, by the late 14th century. The cover of woodland was greatest at c.ad 1400, before forest clearance and agriculture increased in intensity. [source] Do we need land-cover data to model species distributions in Europe?JOURNAL OF BIOGEOGRAPHY, Issue 3 2004Wilfried Thuiller Abstract Aim, To assess the influence of land cover and climate on species distributions across Europe. To quantify the importance of land cover to describe and predict species distributions after using climate as the main driver. Location, The study area is Europe. Methods, (1) A multivariate analysis was applied to describe land-cover distribution across Europe and assess if the land cover is determined by climate at large spatial scales. (2) To evaluate the importance of land cover to predict species distributions, we implemented a spatially explicit iterative procedure to predict species distributions of plants (2603 species), mammals (186 species), breeding birds (440 species), amphibian and reptiles (143 species). First, we ran bioclimatic models using stepwise generalized additive models using bioclimatic variables. Secondly, we carried out a regression of land cover (LC) variables against residuals from the bioclimatic models to select the most relevant LC variables. Finally, we produced mixed models including climatic variables and those LC variables selected as decreasing the residual of bioclimatic models. Then we compared the explanatory and predictive power of the pure bioclimatic against the mixed model. Results, (1) At the European coarse resolution, land cover is mainly driven by climate. Two bioclimatic axes representing a gradient of temperature and a gradient of precipitation explained most variation of land-cover distribution. (2) The inclusion of land cover improved significantly the explanatory power of bioclimatic models and the most relevant variables across groups were those not explained or poorly explained by climate. However, the predictive power of bioclimatic model was not improved by the inclusion of LC variables in the iterative model selection process. Main conclusion, Climate is the major driver of both species and land-cover distributions over Europe. Yet, LC variables that are not explained or weakly associated with climate (inland water, sea or arable land) are interesting to describe particular mammal, bird and tree distributions. However, the addition of LC variables to pure bioclimatic models does not improve their predictive accuracy. [source] Food Security in China and Contingency Planning: the Significance of Grain ReservesJOURNAL OF CONTINGENCIES AND CRISIS MANAGEMENT, Issue 3 2006Hendrik J. Bruins China is inhabited by ca 20 percent of the world population, but has only 7 percent of global arable land and only 6.6 percent of global freshwater resources. These unfavourable relationships between population size and the basic resources for food production , soil and water , require careful food security and contingency planning by the Chinese authorities. The country has been remarkably successful in raising its food production since 1949 at a faster rate (400 percent) than the increase in its population (240 percent). This has basically been achieved by increasing the yields per unit area with enhanced fertilizer use, as the total size of arable land has been decreasing in recent years. Though China attempts to be largely self-sufficient in food grain production, two possible contingency scenarios are suggested that might cause grave problems: (1) severe multi-annual drought; (2) reduced chemical fertilizer manufacturing. If Chinese food production would drop as a result by, say, 33 percent, famine, the dreaded scourge throughout Chinese history, might recur. A shortage of ca 150 million tons of food grains cannot easily be buffered by the volume of food grains annually traded on the world market, ca 240 million tons. Much of this amount tends to be committed already to traditional buyers, as most countries in the world have to import food grains. Cash reserves, therefore, may not guarantee food purchases, because global grain reserves are limited and declining. The formation and maintenance of large internal food grain reserves in China, common in its tradition and ancient history, seem the only realistic contingency planning strategy to avert famine in case of a severe decline in its food production in future crisis years. [source] Assessing poverty, risk and vulnerability: a study on flooded households in rural BangladeshJOURNAL OF FLOOD RISK MANAGEMENT, Issue 1 2010M.I. Rayhan Abstract Flood is a common catastrophe in Bangladesh. This study aimed to examine the poverty, risk and vulnerability for flood hazards. A cross-sectional household survey was carried out after 2 weeks of the flood in four districts in the year 2005. In total, 600 rural households were interviewed through a three-stage stratified random sampling. A utilitarian approach was used to assess flood vulnerability and its components. A set of households' characteristics and shock (flood) variables were used as explanatory variables. The results showed that poverty and idiosyncratic flood risks are positively correlated and highly significant. Households with higher educated members, headed by a male and owners of a dwelling place have been found to be less vulnerable to idiosyncratic flood risk. Possession of arable land and a small family size can reduce poverty and the aggregate flood risk. [source] Dispersal abilities of adult click beetles in arable land revealed by analysis of carbon stable isotopesAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 3 2009Nikolaus Schallhart Abstract 1,The dispersal abilities of agrioted beetles, serious pests on a variety of crops, are poorly known under natural conditions. This hampers their control. We used, for the first time, a stable isotope approach to assess dispersal of adult Agriotes obscurus in arable land. 2,After a diet switch from a C3- to a C4-plant, carbon isotope ratios of A. obscurus larvae significantly changed towards the isotopic signature of the new diet. Moreover, the larval ,13C signatures were transferred to the wing covers of the adult beetles with little distortion. 3,To assess the dispersal abilities under natural conditions, pheromone traps, lured for Agriotes sp., were installed at two study sites in Western Austria. Each site comprised a maize field (= C4-plant) and adjacent C3-grasslands with traps established along a transect of increasing distance to the maize. 4,,13C signatures of wing covers revealed that adult male A. obscurus were able to migrate at least 80 m, which was the maximum distance that dispersal could be traced in the present study. The dispersal behaviour might have been influenced by site-specific factors. 5,The results obtained demonstrate a higher potential of adult male Agriotes to disperse than previously assumed. Moreover, the combination of pheromone trapping and stable isotope analysis proved to be an effective approach to study insect movement and dispersal in arable systems harbouring C3- and C4-crops. [source] Soil-aggregate formation as influenced by clay content and organic-matter amendmentJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 1 2007Stephen Wagner Abstract Naturally occurring wetting-and-drying cycles often enhance aggregation and give rise to a stable soil structure. In comparatively dry regions, such as large areas of Australia, organic-matter (OM) contents in topsoils of arable land are usually small. Therefore, the effects of wetting and drying are almost solely reliant on the clay content. To investigate the relations between wetting-and-drying cycles, aggregation, clay content, and OM in the Australian environment, an experiment was set up to determine the relative influence of both clay content (23%, 31%, 34%, and 38%) and OM amendments of barley straw (equivalent to 3.1,t,ha,1, 6.2,t,ha,1, and 12.4,t,ha,1) on the development of water-stable aggregates in agricultural soil. The aggregate stability of each of the sixteen composite soils was determined after one, three, and six wet/dry cycles and subsequent fast and slow prewetting and was then compared to the aggregate stabilities of all other composite soils. While a single wet/dry cycle initiated soil structural evolution in all composite soils, enhancing macroaggregation, the incorporation of barley straw was most effective for the development of water-stable aggregates in those soils with 34% and 38% clay. Repeated wetting-and-drying events revealed that soil aggregation is primarily based on the clay content of the soil, but that large straw additions also tend to enhance soil aggregation. Relative to untreated soil, straw additions equivalent to 3.1,t,ha,1 and 12.4,t,ha,1 increased soil aggregation by about 100% and 250%, respectively, after three wet/dry cycles and fast prewetting, but were of less influence with subsequent wet/dry cycles. Straw additions were even more effective in aggregating soil when combined with slow prewetting; after three wet/dry cycles, the mean weight diameters of aggregates were increased by 70% and 140% with the same OM additions and by 160% and 290% after six wet/dry cycles, compared to samples without organic amendments. We suggest that in arable soils poor in OM and with a field texture grade of clay loam or finer, the addition of straw, which is often available from preceding crops, may be useful for improving aggregation. For a satisfactory degree of aggregate stability and an improved soil structural form, we found that straw additions of at least 6.2,t,ha,1 were required. However, rapid wetting of straw-amended soil will disrupt newly formed aggregates, and straw has only a limited ability to sustain structural improvement. [source] Chernozem,Soil of the Year 2005JOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 6 2005Manfred Altermann Abstract The proclamation of the "Soil of the Year" was made for the first time in Germany in 2005 on occasion of the World Soil Day. Chernozems were selected for this purpose. In this paper an overview of these groups of soils is given. Chernozems are concentrated in the drought region of Central Germany. A standard profile from the core area of Chernozems developed from loess is presented with comprehensive laboratory analysis. Chernozems developed primarily upon carbonatic loess substrates under summer-dry climatic conditions in an open park-like landscape with isolated forest stands. The development of Chernozems began as early as the late glacial period, and they were fully developed by the Atlantikum age. The far-reaching, uniformly thick humus horizons indicate substrate differences in the loess cover, which are partly the result of bioturbation. Within Germany, Chernozems and Chernozem-like soils make up approx. 3% of the surface area and 5% (approx. 11,000 km2) of the arable land. The results of the Static Fertilization Experiment in Bad Lauchstädt, founded in 1902, clarify the high value of Chernozem for biomass production and the environment. Each loss due to erosion or decrease in surface area reduces the fulfillment of soil ecological functions of the soils and is comparable to a loss of animal and plant species. Therefore, soil scientists and the results of soil research must be more comprehensively implemented for soil preservation, protection, and politics. For acceptance of these goals among the general public and the political-decision makers, the campaign "Soil of the Year" should give some thought-provoking impulses. Schwarzerde , Boden des Jahres 2005 Anlässlich des Weltbodentages wurde in Deutschland für 2005 mit der Schwarzerde erstmalig ein ,Boden des Jahres" proklamiert. Damit soll in der Bevölkerung und bei politischen Entscheidungsträgern ein stärkeres Bewusstsein für den Boden und ein höheres Engagement für den Bodenschutz angeregt werden. Im Beitrag wird ein Überblick über diese Bodengruppe gegeben und ein Standardprofil aus dem Kerngebiet der Schwarzerden aus Löss (Mitteldeutsches Trockengebiet) mit umfassenden Laboranalysen exemplarisch präsentiert. Schwarzerden entwickelten sich vorwiegend auf kalkreichen Lössen unter sommertrockenen Klimabedingungen in einer offenen parkähnlichen Landschaft mit Waldinseln. Die Entstehung der Schwarzerden setzte bereits im Spätglazial ein, und im Atlantikum waren sie voll entwickelt. Die weiträumig gleiche Mächtigkeit der Humushorizonte zeichnet primäre Substratunterschiede in der Lössdecke nach; sie sind nicht nur das Ergebnis einer Bioturbation. In Deutschland nehmen die Schwarzerden und schwarzerdeähnlichen Böden etwa 3 % der Bodenfläche bzw. 5 % (ca. 11.000 km2) der landwirtschaftlichen Nutzfläche ein. Die Ergebnisse des seit 1902 bestehenden Statischen Düngungsversuchs Bad Lauchstädt verdeutlichen den hohen Wert der Schwarzerden für Biomasseproduktion und Umwelt. Jeder Verlust durch Erosion oder Flächenentzug mindert die Erfüllung ökologischer Funktionen der Böden und ist dem Artenverlust von Tieren und Pflanzen gleichzustellen. In der Bodenpolitik müssen deshalb die Ergebnisse der Bodenforschung zum Erhalt und Schutz unserer Böden umfassender als bisher umgesetzt und Bodenwissenschaftler stärker in politische Entscheidungen eingebunden werden. Für die Akzeptanz und Umsetzung dieser Ziele in der Öffentlichkeit soll der ,Boden des Jahres" Impulse geben. [source] Weed vegetation of arable land in Central Europe: Gradients of diversity and species compositionJOURNAL OF VEGETATION SCIENCE, Issue 3 2004Z. Lososová Abstract: Question: What are the main broad-scale spatial and temporal gradients in species composition of arable weed communities and what are their underlying environmental variables? Location: Czech Republic and Slovakia. Methods: A selection of 2653 geographically stratified relevés sampled between 1954,2003 was analysed with direct and indirect ordination, regression analysis and analysis of beta diversity. Results: Major changes in weed species composition were associated with a complex gradient of increasing altitude and precipitation and decreasing temperature and base status of the soils. The proportion of hemicryptophytes increased, therophytes and alien species decreased, species richness increased and beta diversity decreased with increasing altitude. The second most important gradient of weed species composition was associated with seasonal changes, resulting in striking differences between weed communities developed in spring and summer. In summer, weed communities tended to have more neophytes, higher species richness and higher beta diversity. The third gradient reflected long-term changes in weed vegetation over past decades. The proportion of hemicryptophytes and neophytes increased, while therophytes and archaeophytes decreased, as did species richness over time. The fourth gradient was due to crop plants. Cultures whose management involves less disturbances, such as cereals, harboured less geophytes and neophytes, and had higher species richness but lower beta diversity than frequently disturbed cultures, such as root crops. Conclusions: Species composition of Central European weed vegetation is mainly influenced by broad-scale climatic and edaphic factors, but its variations due to seasonal dynamics and long-term changes in agricultural management are also striking. Crop plants and crop-specific management affect it to a lesser, but still significant extent. [source] Genetically Engineered Crops: Their Potential Use for Improvement of Human NutritionNUTRITION REVIEWS, Issue 5 2002Lin Yan Ph.D. Great success has been achieved in increasing agriculture productivity to fulfill human needs during the second half of the 20th century. However, there will be much greater challenges in the future. Based on the current population growth rate of 1.4% per year, the world's population is forecast to increase from the current level of approximately six billion to nine to twelve billion in 50 years. In addition to continuously increasing demand for agricultural production, there is an urgent need to improve the nutritional quality of human diets for this rapidly growing human population. Malnutrition is still a worldwide health issue. Macronutrient and micronutrient deficiencies are prevalent in developing countries, and over-consumption of certain nutrients in developed countries (e.g., saturated fatty acids) is associated with high incidence of certain chronic diseases. Furthermore, there will be declining natural resources such as arable land and water, and the challenges to humans must be met without further degrading the environment. Biotechnology offers a valuable tool to help achieve these goals. This review focuses on the most recent advances in biotechnology, which promise to improve human nutrition by enhancing the nutrient density of plant foods. Issues relating to the safety of food products from genetically engineered crops are also discussed. [source] Land use in prehistoric malta.OXFORD JOURNAL OF ARCHAEOLOGY, Issue 1 2004A re-examination of the maltese, cart ruts' Summary. This paper explores the manufacture and function of the so-called ,cart ruts' within the harsh environment of Malta and proposes that they were deliberately constructed in order to push the boundaries of available arable land and are better identified as field furrows. Using comparative ethnographic evidence as well as archaeological data from European contexts, it is argued that the driving force, which necessitated their manufacture in Malta, lay in socio-economic pressures. It is argued that the ruts are of high antiquity, products of Temple Period intensification and marginalism in land use. [source] ADOPTION AND PRODUCTIVITY IMPACT OF MODERN RICE VARIETIES IN BANGLADESHTHE DEVELOPING ECONOMIES, Issue 2 2006Mahabub HOSSAIN O13; O33 Technological progress has helped Bangladesh to achieve self-sufficiency in rice production in 2001 from a heavy import-dependence, despite doubling of population and a reduction in arable land since its independence in 1971. As the adoption of modern varieties (MV) of rice is reaching a plateau, particularly for the irrigated ecosystem, an important issue is whether the research system will be able to sustain the growth of production. The present paper addresses the following questions: (i) to what extent farmers have been replacing the old MV with the new MV, and (ii) what has been the impact of the variety replacement on productivity and profitability. How crucial is the continuous research and release of improved rice varieties toward improving farm production and income for farmers comes out as a clear message to policymakers from the current paper. [source] Appraisal of the electrical octet method for estimating earthworm populations in arable landANNALS OF APPLIED BIOLOGY, Issue 2 2001O SCHMIDT Summary Quantitative methods are needed for the assessment of the size and composition of earthworm communities. A poorly documented electrical sampling method, Thielemann's octet method, was compared with two long-established methods, formalin extraction and soil hand sorting, in conventional and direct-drilled wheat cropping systems at two sites with medium to heavy textured soils in Ireland. Under all agronomic conditions tested, the electrical method extracted significantly higher earthworm numbers than formalin, but earthworm biomasses were not significantly different. When used routinely over two years during periods of high earthworm activity, the electrical method yielded community estimates that were comparable in both size and species composition to those obtained by soil hand sorting (25 cm depth), except in recently ploughed land. However, Murchieona minuscule, a minute endogeic species, was underestimated by electrical extraction. It is concluded that the electrical octet method can be a reliable and useful alternative to other dynamic methods for estimating earthworm populations, especially in situations where minimum soil disturbance is desirable. [source] Restoration of a species-rich meadow on arable land by transferring meadow blocksAPPLIED VEGETATION SCIENCE, Issue 4 2010Klime Abstract Question: Does transplantation of small blocks of turfs contribute to restoration of species-rich meadows on fallow land? What is the role of vegetative spread and seedling establishment of meadow plants in the neighbourhood of the transplanted turfs? Location: Bílé Karpaty Mountains, SE Czech Republic. Methods: Twenty-five meadow blocks, 0.4 m × 0.4 m in size, were transplanted to fallow land (unfertile and dry) and species composition was monitored in the source area, in the transferred turfs and in their neighbourhood for 3 yr. Multivariate analyses were used to assess successional trends. Results: The transferred meadow blocks served as a source of diaspores for the seed-limited fallow land. Out of 80 transplanted species 17 species spread to adjacent plots within 3 yr. The frequency of plants expanding from the transferred turfs, either vegetatively or by seeds, was relatively low and from 2002 to 2004 a total of 22 species declined in the transferred turfs before expanding to the neighbourhood. Successional trends in species composition of the plots adjacent to the transferred blocks were strongly significant compared with the vegetation of the source area despite the short-term data used for the evaluation. The role of the seed bank in restoration was negligible. Conclusions: In infertile and dry environments, transplanted turfs may significantly speed up restoration, especially if natural sources of target plant seeds are not available in the neighbourhood. However, the restoration process is long-term and not all transferred plants can be expected to establish in the fallow land. [source] Multi-scale responses of plant species diversity in semi-natural buffer strips to agricultural landscapesAPPLIED VEGETATION SCIENCE, Issue 2 2008Maohua Ma Question: How does agricultural land usage affect plant species diversity in semi-natural buffer strips at multiple scales? Location: Lepsämä River watershed, Nurmijärvi, Southern Finland. Methods: Species diversity indicators included both richness and evenness. Plant communities in buffer strips were surveyed in 29 sampling sites. Using ArcGIS Desktop 9.0 (ArcInfo) and Fragstats 3.3 for GIS analysis, the landscape composition around each sampling site was characterized by seven parameters in square sectors at five scales: 4, 36, 100, 196, and 324ha. For each scale, Principle Component Analysis was used to examine the importance of each structural metric to diversity indicators using multiple regression and other simple analyses. Results: For all but the smallest scales (4 ha), two structural metrics including the diversity of land cover types and percentage of arable land were positively and negatively correlated with species richness, respectively. Both metrics had the highest correlation coefficients for species richness at the second largest scale (196 ha). The density of arable field edges between the fields was the only metric that correlated with species evenness for all scales, which had highest predictive power at the second smallest scale (36 ha). Conclusions: Species richness and evenness of buffer strips had scale-dependent relationships to land use in agricultural ecosystems. The results of this study indicated that species richness depends on the pattern of arable land use at large scales, which may relate to the regional species pool. Meanwhile, species evenness depended on the level of field edge density at small scales, which relates to how the nearby farmland was divided by the edges (e.g. many small-scale fields with high edge density or a few big-scale fields with low edge density). This implies that it is important to manage the biodiversity of buffer strips within a landscape context at multiple scales. [source] | |||||||||||||||||||||||||||||||||||||