Leaf litter recycling in benthic and hyporheic layers in agricultural streams with different types of land use

Changes in land use and intensification of agricultural pressure have greatly accelerated the alteration of the landscape in most developed countries. These changes may greatly disturb the adjacent ecosystems, particularly streams, where the effects of pollution are amplified. In this study, we used the leaf litter breakdown rate to assess the functional integrity of stream ecosystems and river sediments along a gradient of either traditional extensive farming or a gradient of vineyard area. In the benthic layer, the total litter breakdown process integrates the temporal variability of the anthropogenic disturbances and is strongly influenced by land use changes in the catchment even though a low concentration of toxics was measured during the study period. This study also confirmed the essential role played by amphipods in the litter breakdown process. In contrast, microbial processes may have integrated the variations in available nutrients and dissolved oxygen concentrations, but failed to respond to the disturbances induced by vineyard production (the increase in pesticides and metal concentrations) during the study period. The response of microbes may not be sensitive enough for assessing the global effect of seasonal agricultural practices. Finally, the leaf litter breakdown measured in the hyporheic zone seemed mainly driven by microbial activities and was hence more affected by vertical exchanges with surface water than by land use practices. However, the breakdown rate of leaf litter in the hyporheic zone may constitute a relevant way to evaluate the impact on river functioning of any human activities that induce massive soil erosion and sediment clogging.     

Soil erosion dynamics response to landscape pattern

Simulating soil erosion variation with a temporal land use database reveals long-term fluctuations in landscape patterns, as well as priority needs for soil erosion conservation. The application of a multi-year land use database in support of a Soil Water Assessment Tool (SWAT) led to an accurate assessment, from 1977 to 2006, of erosion in the upper watershed of the Yellow River. At same time, the impacts of land use and landscape service features on soil erosion load were assessed. A series of supervised land use classifications of Landsat images characterized variations in land use and landscape patterns over three decades. The SWAT database was constructed with soil properties, climate and elevation data. Using water flow and sand density data as parameters, regional soil erosion load was simulated. A numerical statistical model was used to relate soil erosion to land use and landscape. The results indicated that decadal decrease of grassland areas did not pose a significant threat to soil erosion, while the continual increase of bare land, water area and farmland increased soil erosion. Regional landscape variation also had a strong relationship with erosion. Patch level landscape analyses demonstrated that larger water area led to more soil erosion. The patch correlation indicated that contagious grassland patches reduced soil erosion yield. The increased grassland patches led to more patch edges, in turn increasing the sediment transportation from the patch edges. The findings increase understanding of the temporal variation in soil erosion processes, which is the basis for preventing local pollution.     

毛乌素沙地石油天然气矿山地质环境保护与土地复垦适宜性评价及工程设计研究

为探讨半干旱区的土地复垦适宜性评价方法与工程设计,通过毛乌素沙漠周边3个油气项目土地复垦工程的适宜性评价与工程实施对比分析,研究得出毛乌素沙地地区石油天然气项目的适宜性评价过程应针对不同现状问题提出相关的重点地类,针对重点地类进行单独评价,其他复垦单元采取简化评价。工程设计应减少土壤扰动、不设计表土剥覆工程,有风蚀沙埋灾害的地区应对土地复垦与矿山地质灾害工程采取统一的治理措施。     

Total sediment transport by the rivers of Abruzzi (Central Italy): prediction with the RAIZAL model

As sediment transport is mainly correlated with accelerated soil erosion, the study attempted to quantify the sediment transport by relying on qualitative classes of soil erosion risk. The classes were obtained by applying a modified RAIZAL model (MICROLEIS software package) to the most representative catchment basins of the Abruzzi area (Central Italy). They are characterized by eight homogeneous lithological groups (terrigenous and carbonatic units). Each lithological group is related to specific types of morphology, soil and land use. The estimates of total sediment transport obtained using the modified RAIZAL Codex were in good agreement with those measured or estimated by other methods, suggesting that the use of this Codex would be a valid alternative. Electronic Publication     

Description of the test area and reference sampling at Dornach

The selected test area for the comparative evaluation of European methods on sampling and sample preparation of soils (CEEM Soil) at Dornach near Basel (Switzerland) is located at approximately 400 m a.S.l. on the north-west rolling footslope of the Jura mountain chain that has a temperate climate. The area is known to be airborne polluted by emissions of a non-ferrous metal recycling plant. The geology is dominated by Jurassic limestone and (decarbonated) loess loam. The land use is deciduous forest (beech, oak) in the upper part and traditional cherry orchards with permanent grassland which have mostly been converted into arable land. The detailed soil survey distinguishes four different soil mapping units in the test area of 0.61 ha. The reference sampling was performed in a 190-m-long and 20-40 m large transect area following four devices: (1) composite samples (0-10 cm and 0-20 cm), each from 25 stratified single samples of 61 squares of 10 x 10 m; (2) hypotheses and soil horizon-based composite samples at nine locations; (3) horizon-related samples from the four described soil profiles representing the mapping units; and (4) three soil cores with 5-cm interval samples taken in the major land use units. Altogether 301 reference soil samples were taken.     

A method for soil environmental quality evaluation for management and planning in urban areas

Soil represents a complex medium, which makes it difficult to evaluate its quality. In the past, soil quality evaluation was biased towards agricultural production rather than for purposes related to the broad range of functions and services that it performs. Soil function and soil quality in the urban environment differ due to the different needs and roles of soil within the diversity of urban land uses. The quality of urban soil should be evaluated to support public services for good environmental quality management. Planners should also adjust their decisions towards more sustainable urban design. Simple and applicable soil quality evaluation methods accompanied by an operations toolkit that could be used by laypeople are needed.This paper discusses soil functions, soil quality indicators, pedotransfer functions, and urban soil quality. It presents an urban soil quality evaluation method for different land uses within one particular evaluation system. The calculation of three one-value measures of soil quality are introduced: index of soil quality (expresses soil quality/suitability for a particular land use), soil environmental quality index (environmental value of soil) in terms of performing the crucial ecological functions of soil, and land use change index (land use planning impact assessment on soil resources). The use of the method is described in two procedures: urban soil quality control and soil evaluation for urban planning.     

生态系统服务制图单元如何更好地支持风景园林规划设计？

若对生态系统服务（Ecosystem Services,简称ESs）制图单元没有清晰的认识,将有碍于ESs制图结果在风景园林实践中的应用水平。通过系统性评述,综述近11年106篇与ESs制图相关的SCI文章,并将现有ESs制图单元归纳为4种常见类型和3种单元规模。研究发现：在3种风景园林实践的尺度上,ESs制图单元表现出不同的选择优先性,以及对风景园林实践需求回应的不足。对于ESs制图单元的选择,提出3个实践尺度上可能的解决方法以更好地支持风景园林规划设计,包括：引入更多与土地利用单元细节相关的信息参与ESs制图或在明确的地块内进行ESs评估,基于地理/生物物理特征对土地利用单元进行细分以形成具有生态意义的空间单元,以及构建与现实中已有规划管理边界相对应且支持相关生态过程并包含完整生态系统的空间单元。研究结果能够为提升ESs知识在风景园林实践中的应用水平提供新的思路和借鉴。     

重庆市北碚老城区儿童户外活动空间配置 社会绩效评价

为更准确地反映重庆市北碚老城区儿童享有户外活动空间资源的现状,进一步探索城市公共空间配置的社会绩效评价方法,基于行政单元之下更微观的城市空间格局和更精细的常住儿童人口数据,以地形、道路、边界围合及用地性质等因素划定的功能单元作为研究单元,计算各功能单元儿童人均享有面积,进而评价儿童户外活动空间配置的社会绩效。结果表明:北碚老城区缺乏对专属型儿童户外活动空间的建设;儿童户外活动空间配置不公平;相对低绩效水平的功能单元占单元总数的29.41%,未来应首先关注低绩效单元中儿童活动空间的建设。     

Climate impacts on European agriculture and water management in the context of adaptation and mitigation—The importance of an integrated approach

We review and qualitatively assess the importance of interactions and feedbacks in assessing climate change impacts on water and agriculture in Europe. We focus particularly on the impact of future hydrological changes on agricultural greenhouse gas (GHG) mitigation and adaptation options. Future projected trends in European agriculture include northward movement of crop suitability zones and increasing crop productivity in Northern Europe, but declining productivity and suitability in Southern Europe. This may be accompanied by a widening of water resource differences between the North and South, and an increase in extreme rainfall events and droughts. Changes in future hydrology and water management practices will influence agricultural adaptation measures and alter the effectiveness of agricultural mitigation strategies. These interactions are often highly complex and influenced by a number of factors which are themselves influenced by climate. Mainly positive impacts may be anticipated for Northern Europe, where agricultural adaptation may be shaped by reduced vulnerability of production, increased water supply and reduced water demand. However, increasing flood hazards may present challenges for agriculture, and summer irrigation shortages may result from earlier spring runoff peaks in some regions. Conversely, the need for effective adaptation will be greatest in Southern Europe as a result of increased production vulnerability, reduced water supply and increased demands for irrigation. Increasing flood and drought risks will further contribute to the need for robust management practices.The impacts of future hydrological changes on agricultural mitigation in Europe will depend on the balance between changes in productivity and rates of decomposition and GHG emission, both of which depend on climatic, land and management factors. Small increases in European soil organic carbon (SOC) stocks per unit land area are anticipated considering changes in climate, management and land use, although an overall reduction in the total stock may result from a smaller agricultural land area. Adaptation in the water sector could potentially provide additional benefits to agricultural production such as reduced flood risk and increased drought resilience.The two main sources of uncertainty in climate impacts on European agriculture and water management are projections of future climate and their resulting impacts on water and agriculture. Since changes in climate, agricultural ecosystems and hydrometeorology depend on complex interactions between the atmosphere, biosphere and hydrological cycle there is a need for more integrated approaches to climate impacts assessments. Methods for assessing options which “moderate” the impact of agriculture in the wider sense will also need to consider cross-sectoral impacts and socio-economic aspects.     

Development of agro-environmental scenarios to support pesticide risk assessment in Europe

This paper describes work carried out within the EU-funded FOOTPRINT project to characterize the diversity of European agricultural and environmental conditions with respect to parameters which most influence the environmental fate of pesticides. Pan-European datasets for soils, climate, land cover and cropping were intersected, using GIS, to identify the full range of unique combinations of climate, soil and crop types which characterize European agriculture. The resulting FOOTPRINT European agro-environmental dataset constitutes a large number of polygons (approximately 1,700,000) with attribute data files for i) area fractions of annual crops related to each arable-type polygon (as an indicator of its probability of occurrence); and, ii) area fractions of each soil type in each polygon (as an indicator of its probability of occurrence). A total of 25,044 unique combinations of climate zones, agricultural land cover classes, administrative units and soil map units were identified. The same soil/crop combinations occur in many polygons which have the same climate while the fractions of the soils and arable crops are different. The number of unique combinations of climate, soil and agricultural land cover class is therefore only 7961. 26-year daily meteorological data, soil profile characteristics and crop management features were associated with each unique combination. The agro-environmental scenarios developed can be used to underpin the parameterization of environmental fate models for pesticides and should also have relevance for other agricultural pollutants. The implications for the improvement and further development of risk assessment procedures for pesticides are discussed.     

Transition of the satoyama landscape in the urban fringe of the Tokyo metropolitan area from 1880 to 2001

An explicit understanding of past landscapes is a basic and important issue, which enables deeper understanding of current landscapes in a longer context and gives useful suggestion to today's landscape planning. In this paper, transition of the traditional Japanese agricultural landscape (satoyama landscape) over a relatively long temporal scale (1880–2001), and its inherent dynamics in each of four socioeconomically based time periods in two topographically different areas around the Tokyo metropolitan area was studied. Information derived from historical records and interviews was used to differentiate four socioeconomic periods, and to support and explain the results of the analysis. Old maps and aerial photographs were used to create land use maps, which were analyzed using GIS. The results illustrated drastic landscape change from agricultural to urban landscape, with unique land use and transition patterns in each study area. A large part of both study areas was affected by bi-directional conversion between woodlands and crop fields in the early part of the study period, in the form of shifting agriculture. Our results also showed that the landscapes are becoming less dynamic and it may suggest reconsideration for land use planning, which will lead to more stabilized landscapes.     

Same Land Cover,Same Land Use at the Large Scale,Different Landscapes at the Small Scale: Landscape Change in Olive Plantations on Lesvos Island,Greece

In this paper, agricultural landscape change at the small scale (for example, at the farm and field level) is studied to conceptualize the processes that change these landscapes (such as features, forms and functions) according to the decisions that farmers make. The case study is olive plantations on the island of Lesvos, Greece. The five-year differences in land cover, land use and landscape at the small scale of a number of olive fields in the same area are studied in three dimensions: symbolic, productive and ecological, with data that come from the observation of practices and vegetation measurements. A conceptual framework is constructed that links the changes of six different landscapes at the individual olive field level with specific management choices of farmers. Findings demonstrate that although olive plantations are of the same land cover and land use class as at the large scale, diverging practices create different landscapes at the small scale along a continuous line with many intermediate cases. The findings also demonstrate that the whole system is dynamic, with the different small-scale landscapes changing into each other continuously due to different practices. Understanding this dynamic diversity requires studying human interventions at the right scale, the one that corresponds to the scale of the changes at the farm.     

Transition of the satoyama landscape in the urban fringe of the Tokyo metropolitan area from 1880 to 2001

An explicit understanding of past landscapes is a basic and important issue, which enables deeper understanding of current landscapes in a longer context and gives useful suggestion to today's landscape planning. In this paper, transition of the traditional Japanese agricultural landscape (satoyama landscape) over a relatively long temporal scale (1880–2001), and its inherent dynamics in each of four socioeconomically based time periods in two topographically different areas around the Tokyo metropolitan area was studied. Information derived from historical records and interviews was used to differentiate four socioeconomic periods, and to support and explain the results of the analysis. Old maps and aerial photographs were used to create land use maps, which were analyzed using GIS. The results illustrated drastic landscape change from agricultural to urban landscape, with unique land use and transition patterns in each study area. A large part of both study areas was affected by bi-directional conversion between woodlands and crop fields in the early part of the study period, in the form of shifting agriculture. Our results also showed that the landscapes are becoming less dynamic and it may suggest reconsideration for land use planning, which will lead to more stabilized landscapes.     

Stream cation concentrations and losses from drainage basins with contrasting land uses in Southern Ontario

The concentration and loss of major cations from 22 watersheds near Toronto, Ontario, was measured over a 27-month period. Calcium and potassium concentrations exhibited a positive relationship with crop area and a negative correlation with abandoned farm land + forest and areas of sand + sandy loam soil. The influence of soil properties and farming activities on streám cation levels could not be separated because of multicollinearity between land use and soils. An absence of correlation between crop area and annual losses of calcium and potassium can be attributed to lower annual stream discharges in agricultural watersheds in comparison to watersheds containing extensive areas of forest and abandoned farm land. Stream concentrations and losses of potassium and sodium were positively correlated with urban land use. Detailed water sampling in the vicinity of urban centres confirmed that these areas are important contributors of sodium, and to a lesser extent, of potassium to streams. Magnesium concentration was influenced mainly by differences in watershed hydrology and no correlation was evident with urban or agricultural land use.     

Loss rates of urban biocides can exceed those of agricultural pesticides

Biocides and pesticides are used to control unwanted organisms in urban and agricultural areas. After application, they can be lost to surface waters and impair water quality. Several national consumption studies have shown that urban and agricultural use may be in the same range. It is difficult to judge whether this results in similar loadings of surface waters because there is a lack of sound, comparative studies addressing urban and agricultural losses simultaneously.The aim of this study is thus to relate the biocide and pesticide loads found in surface waters to their respective urban and agricultural usage (loss rates). To simultaneously assess the loss rates, we conducted a comprehensive field study in a catchment of mixed land use on the Swiss Plateau. The study area was divided into four sub-catchments with different degrees of urban and agricultural land use. In addition, we studied the only wastewater treatment plant, a combined sewer overflow and a storm sewer within the area. Rain events were sampled at high temporal resolution from March to November, 2007. Information on agricultural applications was gained from local farmers. For urban uses, consumption estimations were conducted based on statistical and product information.Despite substantially lower amounts used, the measured loads of urban biocides were in the same range as the most widely-used agricultural pesticides. The lower usage was compensated by urban loss rates that were up to ten times higher than agricultural ones (0.6 to 15% for urban, 0.4 to 0.9% for agricultural compounds). For most biocides and pesticides, the loads were controlled by rain events. Besides the rain-controlled losses, some urban-used biocides (e.g. diazinon) showed a continuous load independent of rain events and season. This study demonstrates that in catchments with mixed land use, mitigation strategies have to pay sufficient attention to the urban sources.     

基于“三生”功能的柳州市国土空间适宜性评价

国土空间适宜性评价是空间规划的前提和基础。文章以国土资源现状为本底,从土地资源、水资源、生态、环境、气候、灾害和区位等资源环境要素角度构建评价指标体系,从资源本底和土地利用现状两方面分别对柳州市开展生态保护、农业生产及城镇建设适宜性评价,并将生态、农业和城镇综合评价结果在空间上进行叠加分析,逐块分析每个网格单元需要的生态保护、利于农业生产与适宜城镇开发建设的功能等级,确定各图斑单元的功能属性,划分形成以生态保护、农业发展和城镇开发为主导功能的三类国土空间格局。     

Abandoned farmlands as components of rural landscapes: An analysis of perceptions and representations

In spite of its importance in some agricultural landscape, abandoned farmland remains relatively little studied. Yet it is central to several land management issues: ecological (biodiversity), economic (agricultural or forest productivity) and landscape issues. In order to better address these issues, this study proposes to define how abandoned farmland is perceived in an intensive agricultural landscape. Using photographs, the perceptions of abandoned farmland (herbaceous and shrub dominated) and 5 other land uses (hay fields, corn fields, pastures, woodlots and plantations) were measured from a sample of 33 abandoned farmland owners in order to compare and rank the perceptions of abandoned farmland to that of other types of land use. Perceptions of landscape changes and the importance of abandoned farmland within properties were studied. The statistical analyses used allowed us to establish relationships between the different perceptions and the socio-economic characteristics and value indicators of the land owners. The analyses establish that abandoned farmland produces the most negative perceptions, followed by corn fields. Conversely, woodlots are the land use that is the most appreciated. The attitude towards the environment was one of the variables most often significant in explaining the perceptions encountered. Analysis of landscape evolution reveals an intensification of agricultural practices that may lead to the conversion of abandoned farmlands into cultivated land. Finally, abandoned farmland is perceived, at the scale of the individual property, as the land use having the least value (as opposed to corn fields) and being the least appreciated (as opposed to forests).     

Abandoned farmlands as components of rural landscapes: An analysis of perceptions and representations

In spite of its importance in some agricultural landscape, abandoned farmland remains relatively little studied. Yet it is central to several land management issues: ecological (biodiversity), economic (agricultural or forest productivity) and landscape issues. In order to better address these issues, this study proposes to define how abandoned farmland is perceived in an intensive agricultural landscape. Using photographs, the perceptions of abandoned farmland (herbaceous and shrub dominated) and 5 other land uses (hay fields, corn fields, pastures, woodlots and plantations) were measured from a sample of 33 abandoned farmland owners in order to compare and rank the perceptions of abandoned farmland to that of other types of land use. Perceptions of landscape changes and the importance of abandoned farmland within properties were studied. The statistical analyses used allowed us to establish relationships between the different perceptions and the socio-economic characteristics and value indicators of the land owners. The analyses establish that abandoned farmland produces the most negative perceptions, followed by corn fields. Conversely, woodlots are the land use that is the most appreciated. The attitude towards the environment was one of the variables most often significant in explaining the perceptions encountered. Analysis of landscape evolution reveals an intensification of agricultural practices that may lead to the conversion of abandoned farmlands into cultivated land. Finally, abandoned farmland is perceived, at the scale of the individual property, as the land use having the least value (as opposed to corn fields) and being the least appreciated (as opposed to forests).     

A methodology for the assessment of rehabilitation success of post mining landscapes--sediment and radionuclide transport at the former Nabarlek uranium mine, Northern Territory, Australia

Protection of the environment post-mining is an important issue, especially where runoff and erosion can lead to undesirable material leaving post-mining landscapes and contaminating surrounding land and watercourses. Methods for assessment of the environmental impact and long-term behaviour of post-mining landforms based on scientific methodology are needed especially where field data are absent or poor. An appraisal of the former Nabarlek uranium mine was conducted to assess the site from a soil erosion perspective as part of an independent evaluation of overall rehabilitation success. Determination of the gross erosion occurring, sediment discharge to Cooper Creek and the resultant sediment associated radionuclide load in Cooper Creek were the primary objectives of the study. These objectives were achieved through the application of several models using parameter values collected from the site. The study found that the area containing the mill tailings repository is extremely stable and meets the guidelines established for long-term storage of uranium mill tailings. Most other areas on the site are stable; however there are some areas with a high sediment loss. Sediment concentration in Cooper Creek, which drains the site, was found to be within the Australian water quality guidelines for fresh water, however sediment concentrations in tributaries were found to exceed recommended levels. Radionuclide determinations on soil samples showed that the highest specific activities (Bq kg-1) were present on a small (0.44 ha) area with a relatively high erosion rate. This small area contributed the majority of the estimated flux to Cooper Creek of uranium-series radionuclides sorbed or structurally incorporated to eroded soil particles sourced from the mine site. This study provides a methodology for assessment of the erosional stability of such a landscape and consequent impact on water quality, using extensive field data and readily available and well known models and methodologies.     

Environmental implications of three modern agricultural practices: Conservation Agriculture,the System of Rice Intensification and Precision Agriculture

Substantial and rapid changes in agricultural land management practices are being made in many countries on all five inhabited continents: Conservation Agriculture, comprising practices that avoid or minimise mechanical soil disturbance, maintain a protective soil mulch cover, and produce crops in rotations or associations; the System of Rice Intensification, in which rice is grown in mainly moist, aerobic soils; and Precision Agriculture, using practices that optimise the use of seed, fertilisers and other production inputs. These management systems provide considerable financial benefits to farmers as well as important environmental benefits, including reversal of land degradation, reduction of river pollution, increased carbon sequestration and reduced greenhouse gas emissions. The nature and scale of these benefits need to be measured and monitored in different agro-ecological and socio-political environments. The reasons for different rates of adoption of these improved practices between and within countries also deserve examination.