Agricultural Land Use Intensity Research Articles

Aquatic plant dynamics of Waituna Lagoon, New Zealand: trade-offs in managing opening events of a Ramsar site

Coastal lagoons are at risk internationally due to impacts associated with human-induced land use change. The resilience of aquatic macrophytes in these systems is threatened by altered hydrological regimes, elevated nutrient loading, and increased dominance of nuisance species. We describe the aquatic plant dynamics of the Waituna Lagoon Ramsar Site, a 1,350 ha lagoon frequently opened to the sea for flood mitigation which is characterised by fluctuating water levels and salinity. The shallow lagoon supports a macrophyte community dominated by Ruppia megacarpa and R. polycarpa. Repeated survey of 48 sites across the lagoon during late summer in 2009, 2010 and 2011 were applied to describe aquatic plant composition and abundance. This period coincided with three opening events (winter 2008; winter 2009; spring 2010) when the lagoon switched from a predominantly fresh-brackish system to being influenced by tidal exchange and lower water levels. The lagoon experienced a period of 43 days open to the sea in 2008–2009, 67 days in 2009–2010 and 181 days in 2010–2011, during which macrophytes were subject to saline conditions in excess of 10 ppt. We observed a decline in the occurrence of Ruppia from 2009 (69 % sites) to 2011 (23 % sites). The shift in productivity was associated with the duration of the open phase and the period plants were subject to saline conditions >20 ppt and low water levels. The resilience of the system is also at risk from increased algal-dominance due to the intensification of agricultural land use occurring in the Waituna Lagoon catchment. While lagoon opening events cause extreme changes in water depth and salinity that can limit macrophyte growth, they also provide a mechanism to reduce the effects of eutrophication. Understanding these trade-offs is pivotal in management decisions regarding the likely impact of opening events on the ecological character of coastal lagoons.

Measuring agricultural land-use intensity – A global analysis using a model-assisted approach

Human activities such as research & development, infrastructure or management are of major importance for agricultural productivity. These activities can be summarized as agricultural land-use intensity. We present a measure, called the τ-factor, which is an alternative to current measures for agricultural land-use intensity. The τ-factor is the ratio between actual yield and a reference yield under well defined management and technology conditions. By taking this ratio, the physical component (soils, climate), which is equal in both terms, is removed. We analyze global patterns of agricultural land-use intensity for 10 world regions and 12 crops, employing reference yields as computed with a global crop growth model for the year 2000. We show that parts of Russia, Asia and especially Africa had low agricultural land-use intensities, whereas the Eastern US, Western Europe and parts of China had high agricultural land-use intensities in 2000. Our presented measure of land use intensity is a useful alternative to existing measures, since it is independent of socio-economic data and allows for quantitative analysis.

Factors affecting plant species richness in field boundaries in the Mediterranean region

Field boundaries are expected to support the maintenance of biodiversity in agroecosystems, since they provide the habitat for a range of plant species. However, plant diversity in field boundaries has decreased substantially in recent decades. This pattern is generally linked with the intensification of agricultural land use at field and landscape level. Therefore, we aimed to test the effect of farming management (field and boundary management), boundary structure (width and habitat assemblage considering the Mediterranean grassland element), and landscape heterogeneity on plant species richness of field boundaries. Plants were recorded along 30 field boundaries next to organic fields and 30 next to conventional fields located in 15 agrarian localities of NE Iberian Peninsula along a gradient of landscape complexity. A total of 517 plant species were identified in the 60 field boundaries. We recorded 162 species (31%) catalogued as rare, very rare or extremely rare in the flora of the Catalan Countries. Our results showed the importance of landscape heterogeneity, field management and habitat assemblage, since they were found to be the most influential variables for plant species richness; whereas boundary width and boundary management were seen to contribute less to explaining plant diversity. Accordingly, agri-environmental schemes should be designed to promote organic farming and maintain the structure of the landscape mosaic in order to benefit plant diversity in field boundaries in the Mediterranean region.

Effect of small-scale woodland clearing and thinning on vertebrate fauna in a largely intact tropical savanna mosaic

Context Habitat degradation and fragmentation of vegetation can transform and deplete local wildlife populations, and is a key threatening process globally. In northern Australian tropical savannas, clearing is relatively rare across the biome, although it is slowly intensifying as a result of increasing agricultural development. However, the terrestrial vertebrates in these largely intact landscapes are undergoing current population declines because of a variety of land-management changes, one of which is increasing land clearing; therefore, there is a need to understand the relative effect of small-scale land clearing the fauna. Aims The present study examined the variation in abundance of birds, mammals and reptiles in intact, thinned and cleared Eucalyptus woodlands in a tropical savanna bioregion. Methods The vertebrate fauna were sampled in 88 sites over two general geographic locations within the Desert Uplands in 2005 and 2006. Standardised 1-ha surveys were employed in a single vegetation type and across three treatments. As two discrete locations were examined, linear mixed models were used in the analysis. Key results The fauna composition varied significantly across the intact, thinned and cleared sites. Bird species richness reduced from intact to thinned and cleared sites, and reptile richness and abundance declined in cleared sites, but was largely unaffected by thinning. Seventeen bird species recorded significant variation in abundance across the three vegetation structural types, with 12 most abundant in the intact sites. Mammals on the whole were recorded in very low abundances and in few sites. For reptiles, two were most abundant in thinned sites and three in intact sites. Conclusions In the present study, we have demonstrated that small-scale clearing and vegetation manipulation via thinning, even within largely intact tropical savanna woodland, can cause localised depletion of some species, although most notably where the vegetation disruption was most severe (i.e. clearing). Birds are most affected, and many species that declined in abundance are the same as those that suffered severe population reductions as a result of broad-scale clearing in south-eastern Australia. Implications The proposed increase in the intensity of agricultural land use in northern Australia will result in incremental landscape change as a result of clearing. Understanding how the gradual reduction of vegetation cover and habitat will change the faun assemblage is important for pre-emptive conservation planning. This is vital to avoid the mistakes of extensive landscape change in southern Australia that has left a legacy of a permanently depleted fauna.

Landscape genetics of a recent population extirpation in a burnet moth species

The intensification of agricultural land use over wide parts of Europe has led to the decline of semi-natural habitats, such as extensively used meadows, with those that remain often being small and isolated. These rapid changes in land use during recent decades have strongly affected populations inhabiting these ecosystems. Increasing habitat deterioration and declining permeability of the surrounding landscape matrix disrupt the gene flow within metapopulations. The burnet moth species Zygaena loti has suffered strongly from recent habitat fragmentation, as reflected by its declining abundance. We have studied its population genetic structure and found a high level of genetic diversity in some of the populations analysed, while others display low genetic diversity and a lack of heterozygosity. Zygaena loti was formerly highly abundant in meadows and along the skirts of forests. However, the species is currently restricted to isolated habitat remnants, which is reflected by the high genetic divergence among populations (F ST: 0.136). Species distribution modelling as well as the spatial examination of panmictic clusters within the study area strongly support a scattered population structure for this species. We suggest that populations with a high level of genetic diversity still represent the former genetic structure of interconnected populations, while populations with low numbers of alleles, high F IS values, and a lack of heterozygosity display the negative effects of reduced interconnectivity. A continuous exchange of individuals is necessary to maintain high genetic variability. Based on these results, we draw the general conclusion that more common taxa with originally large population networks and high genetic diversity suffer stronger from sudden habitat fragmentation than highly specialised species with lower genetic diversity which have persisted in isolated patches for long periods of time.

Climate change, agricultural insecticide exposure, and risk for freshwater communities

Climate change exerts direct effects on ecosystems but has additional indirect effects due to changes in agricultural practice. These include the increased use of pesticides, changes in the areas that are cultivated, and changes in the crops cultivated. It is well known that pesticides, and in particular insecticides, affect aquatic ecosystems adversely. To implement effective mitigation measures it is necessary to identify areas that are affected currently and those that will be affected in the future. As a consequence, we predicted potential exposure to insecticide (insecticide runoff potential, RP) under current conditions (1990) and under a model scenario of future climate and land use (2090) using a spatially explicit model on a continental scale, with a focus on Europe. Space-for-time substitution was used to predict future levels of insecticide application, intensity of agricultural land use, and cultivated crops. To assess the indirect effects of climate change, evaluation of the risk of insecticide exposure was based on a trait-based, climate-insensitive indicator system (SPEAR, SPEcies At Risk). To this end, RP and landscape characteristics that are relevant for the recovery of affected populations were combined to estimate the ecological risk (ER) of insecticides for freshwater communities. We predicted a strong increase in the application of, and aquatic exposure to, insecticides under the future scenario, especially in central and northern Europe. This, in turn, will result in a severe increase in ER in these regions. Hence, the proportion of stream sites adjacent to arable land that do not meet the requirements for good ecological status as defined by the EU Water Framework Directive will increase (from 33% to 39% for the EU-25 countries), in particular in the Scandinavian and Baltic countries (from 6% to 19%). Such spatially explicit mapping of risk enables the planning of adaptation and mitigation strategies including vegetated buffer strips and nonagricultural recolonization zones along streams.

Arable land use intensity change in China from 1985 to 2005: evidence from integrated cropping systems and agro economic analysis

SUMMARYA cropping system is the consequence of environmental and socio-economic conditions that determine the intensity of agricultural land use. Accurate information on regional land use intensity and changes in land use intensity is important for food security and sustainable resource management in China. Therefore, a better understanding of the spatial and temporal changes in arable land use intensity (ALUI) based on the cropping system used is essential to comprehend the changes in land use and the sustainability of the food system. The purpose of the present study was to investigate the spatial difference in ALUI and how it has changed in China by comparing data on cropping systems from 1985 and 2005. The basic cropping system data were acquired from the 1985 reference book and the 2005 national land use investigation. The ALUI was defined by the application of inputs (irrigation water and fertilizer) to arable land and the duration of disturbances (the duration of cultivation and the frequency of cropping), and it was calculated using the information entropy approach at the cropping region scale (cropping region being defined by the geographical and climatic conditions at the beginning of the 1980s). Spatial and temporal changes in the ALUI in China over the past two decades were observed and analysed. The results indicated a clear pattern in ALUI, increasing from the north to the south in 2005. Furthermore, the ALUI significantly increased after the 1980s, but the rate of increase was lower in the south than in the north. The most intensive land use in 1985 was in the area of the lower reach of the Yangtze and Huai Rivers, and it expanded northwards towards the Huang-Huai-Hai plain in 2005. The large increase in intensity in the northern single-cropping regions was strongly associated with a rapid increase in inputs and longer duration of cultivation. Decreases in duration of cultivation and planting area helped slow the ALUI increase in multiple cropping regions, which were concentrated in coastal and economically developed regions where more fertile soil and suitable climates existed, allowing the growth of multiple crops. These results suggested that a decrease in the planting area and a slow increase in the ALUI in the lower reaches of the Yangtze River, South China, Southeast China and Northeast China should be of concern, but land use in some western regions should maintain the land production capacity to build sustainable cropping. In the future, it will be necessary to produce more food in a more sustainable way.

Agricultural Land Use Intensity and Its Determinants in Ecologically-vulnerable Areas in North China: A Case Study of Taipusi County, Inner Mongolia Autonomous Region

Abstract: Based on rural household survey data in Taipusi County in Inner Mongolia Autonomous Region, this article analyzes agricultural land use intensity and its determinants. The results reveal marked differences of agricultural land use intensity among households with different ages of householders, proportion of non-farm participants, total agricultural land area, land fragmentation and land utilization capacity. (i) Households with older householders and households with a smaller proportion of non-farming laborers generally spend more time on managing their land and invest less capital and materials than other households. The proportion of non-farming laborers within younger households is relatively high, and they tend to invest more capital and materials because the income derived from non-farm employment relaxes their financial constraints, (ii) Land fragmentation is an important determinant of land use intensity. Households with a bigger land size per plot usually spend less time and invest more ...

Fish and land use influence Gammarus lacustris and Hyalella azteca (Amphipoda) densities in large wetlands across the upper Midwest

Gammarus lacustris and Hyalella azteca (hereafter G. lacustris and H. azteca, respectively) are important components of secondary production in wetlands and shallow lakes of the upper Midwest, USA. Within the past 50 years, amphipod densities have decreased while occurrences of fish and intensity of agricultural land use have increased markedly across this landscape. We investigated influences of fish, sedimentation, and submerged aquatic vegetation (SAV) on densities of G. lacustris and H. azteca in semipermanent and permanent wetlands and shallow lakes (n = 283) throughout seven eco-physiographic regions of Iowa, Minnesota, and North Dakota during 2004–2005. G. lacustris and H. azteca densities were positively correlated with densities of SAV (P < 0.001 and P < 0.001, respectively). Both species were negatively correlated with densities of large fish (non-Cyprinidae; P = 0.01 and P = 0.013, respectively) and with high densities of fathead minnows (Pimephales promelas; P < 0.001 and P = 0.033, respectively). H. azteca densities also were negatively correlated with densities of small fish (e.g., other minnows [Cyprinidae] and sticklebacks [Gasterosteidae]; P = 0.048) and common carp (Cyprinus spp.; P = 0.022). G. lacustris densities were negatively correlated with high levels of suspended solids (an index for sedimentation; P < 0.001). H. azteca densities were positively correlated with the width of upland-vegetation buffers (P = 0.004). Our results indicate that sedimentation and fish reduce amphipod densities and may contribute to the current low densities of amphipods in the upper Midwest. Thus, removing/excluding fish, and providing a thick buffer of upland vegetation around wetlands may help restore amphipod densities and wetland and water quality within this landscape.

Global Patterns of Cropland Use Intensity

This study presents a global scale analysis of cropping intensity, crop duration and fallow land extent computed by using the global dataset on monthly irrigated and rainfed crop areas MIRCA2000. MIRCA2000 was mainly derived from census data and crop calendars from literature. Global cropland extent was 16 million km2 around the year 2000 of which 4.4 million km2 (28%) was fallow, resulting in an average cropping intensity of 0.82 for total cropland extent and of 1.13 when excluding fallow land. The lowest cropping intensities related to total cropland extent were found for Southern Africa (0.45), Central America (0.49) and Middle Africa (0.54), while highest cropping intensities were computed for Eastern Asia (1.04) and Southern Asia (1.0). In remote or arid regions where shifting cultivation is practiced, fallow periods last 3–10 years or even longer. In contrast, crops are harvested two or more times per year in highly populated, often irrigated tropical or subtropical lowlands where multi-cropping systems are common. This indicates that intensification of agricultural land use is a strategy that may be able to significantly improve global food security. There exist large uncertainties regarding extent of cropland, harvested crop area and therefore cropping intensity at larger scales. Satellite imagery and remote sensing techniques provide opportunities for decreasing these uncertainties and to improve the MIRCA2000 inventory.

Application of a direct toxicity assessment approach to assess the hazard of potential pesticide exposure at selected sites on the Crocodile and Magalies rivers, South Africa

The potentially hazardous effects of agricultural pesticide usage in the Crocodile (west) Marico catchment were evaluated using the Danio rerio and Daphnia pulex lethality, Selenastrum capricornutum growth inhibition and the Ames mutagenicity plate incorporation assays. Hazard assessment categories are proposed to standardise the output of the different toxicity assessments. Sites were categorised according to the toxicity hazard indicated and were related to the gradients of agricultural land-use intensity at each site. Intensive agricultural sites showed the highest effects to all tested biota. Receiving water at urban sites associated with increased nutrients and lowest pesticide usage showed few adverse effects, while the relatively unimpacted site indicated no hazard to any organism, and only a slight stimulation to algal growth. Weighted hazard scores indicated that the unimpacted sites were least hazardous, falling within a B category, the urban sites were moderately hazardous (C category), and the agricultural sites (D category) had the highest potential impacts on aquatic organisms. This study demonstrated the usefulness of using the hazard assessment approach and the role it could play in assessing site-specific potential toxicity hazards of river water impacted by agrochemicals. It can be used together with other assessment methods, such as biological indices, in a tiered approach.

Agricultural land use intensity based on emergy analysis

Agricultural land use intensity based on emergy analysis

Historical soil erosion by water in Germany: Scales and archives, chronology, research perspectives

The published record of historical soil erosion by water in Germany as deduced from dated slope deposits ( n = 306), alluvial sediments ( n = 120) and lake sediments is summarized in this paper. The number of sediments investigated reflects the state of knowledge chronology of historical soil erosion and to a certain degree the intensity of the human impact on German landscapes during the Holocene. Even though few data of calculated historical soil erosion intensities exist, an estimation of historical soil erosion in Germany combining the available data has been calculated. Soil erosion in Germany occurred first locally during the Early Holocene, probably triggered by climatic variability. From the Neolithic onward, the record reflects the human impact according to agricultural land use. The observed variability indicates phases of weaker and regained intensity of agricultural land use in Germany. Few records characterise the early and middle Bronze Age (ca. 2000–1600 BC), and the migration period and the early Medieval Times (ca. 400–1000 AD). Surprisingly, for the Roman Emperor Times (ca. 1–400 AD) a decreasing number of soil sediments is recorded even when the data from southern Germany is examined separately. Phases characterised by an increase in soil erosion were the late Bronze Age and pre-roman Iron Age (ca. 1600 BC–1 AD), the high and late Medieval Times (ca. 1000–1350 AD) and the Modern Times (ca. 1500 AD until today). Some extraordinary heavy precipitation events (late 18th–early 19th, first half of 14th century, pre-roman Iron Age) topped the even high soil erosion intensities. Research gaps as well as potential for future research as derived from the available data are outlined.

The impact of land use and land cover changes on soil moisture and hydraulic conductivity along the karst hillslopes of southwest China

The understanding of the temporal and spatial dynamics of soil moisture and hydraulic property is crucial to the study of several hydrological and ecological processes. Karst environments are extremely fragile because of thin soil and small soil water holding capacity. A marked intensification of agricultural land use and deforestation due to increase of population and thus expansion of agricultural areas has made the karst environment even more delicate. In this study, the soil moisture contents (SMC) and hydraulic conductivities (K) along four karst hillslopes were measured in situ by time domain reflectometry and the Guelph Permeameter, respectively, at test plots, each of which has a different vegetative cover, landform, land surface slope, soil property and content of rock fragment. The statistical results from the measurements show that land cover changes strongly affect the distribution of soil moisture and hydraulic properties. Compared with SMC in the bare soil areas, SMC values are 30.5, 20.1 and 10.2% greater in the forest, shrub and grass areas, respectively. Vegetation roots significantly increase permeability of low-layer silt soils. Measured K values were 0.8, 0.6 and 0.01 cm/min for the forest, agriculture and bare soil areas, respectively. When the forest was destroyed by fire or cut to become an agricultural area or bare soils, SMC would be reduced by 13.1 and 32.1%, respectively. If deforestation leads to strong rock desertification, SMC was reduced by 70%. Bedrock fractures significantly reduce the SMC in the overlying layer, but increase K values. SMC values of 30–45% would be reduced to 17–30% for the soil layer embedding rocks with and without fractures, respectively. K values could be increased from 1.0 to 8.5 cm/min. SMC are sensitive to terrain. A slope angle increase of 1° would reduce SMC about 0.82%. These changes resulting from land cover and land use alterations offer useful information to further investigate the response of ecosystem evolution to hydrodynamic processes.

Geo-ecological spatial pattern analysis of the island of Fogo (Cape Verde)

With its small-scale climatic, floristic and geo-ecological differentiation, the island of Fogo is an optimal research area for understanding semi-arid island ecosystems in the marginal tropics. Because of the high variability in precipitation, the archipelago of Cape Verde has a potentially high ecological vulnerability, which is caused mainly by population growth, intensification of agricultural land use and increasing tourism. In this context, a geo-ecological spatial pattern analysis has been conducted for Fogo, including several types of geo-ecological layers like vegetation, elevation, aspect, soil and geology. The different kinds of spatial patterns that are detected can be used as a first tool to display distinctive levels of ecological vulnerability. These levels could constitute a base for sustainable land use planning and the redevelopment of agricultural strategies.

Diversity and abundance of earthworms across an agricultural land-use intensity gradient

Understanding how communities of important soil invertebrates vary with land use may lead to the development of more sustainable land-use strategies. We assessed the abundance and species composition of earthworm communities across six replicated long-term experimental ecosystems that span a gradient in agricultural land-use intensity. The experimental systems include a conventional row-crop agricultural system, two lower-intensity row-crop systems (no-till and tilled organic input), an early successional old-field system, a 40–60 years old coniferous forest plantation, and an old-growth deciduous forest system. Earthworm populations varied among systems; they were lowest in the most intensively managed row-crop system (107 m −2) and coniferous forest (160 m −2); intermediate in the old-field (273 m −2), no-till (328 m −2) and tilled organic (344 m −2) cropping systems; and highest in the old-growth deciduous forest system (701 m −2). Juvenile Aporrectodea species were the most common earthworms encountered in intensively managed systems; other species made up a larger proportion of the community in less intensively managed systems. Earthworm community biomass and species richness also varied and were lowest in the conventional row-crop system and greatest in the old-growth forest system. These results suggest that both land-use intensity and land-use type are strong drivers of the abundance and composition of earthworm communities in agricultural ecosystems.

Intensity of agricultural land-use and farmland birds in the Baltic States

There was a clear indication that the more intensively farmed areas across the Baltic States of Estonia, Latvia and Lithuania provided habitat for fewer bird species and individuals. The abundance of farmland specialist birds was significantly lower by 20% in the more intensive areas as compared to less intensive ones. The difference could partly be explained by the more heterogeneous landscape and field areas in the latter. An analysis of the data from homogeneous arable fields indicated that agricultural intensification was reflected in a tangible decrease in farmland bird abundance, especially in species in need of edge structures. Considerable improvements are needed in conservation safeguards for the region facing intensification of production.

Farmland bird communities in the Baltic region: impact of agricultural intensification and farmers’ attitudes

Intensification of agricultural land-use was shown to be the key reason behind declines in wildlifespecies associated with farmland. I looked at scenarios of agricultural development across the Baltic states ofEstonia, Latvia and Lithuania, and the ways they are seen to affect farmed environments as a habitat offarmland bird species. Community richness and abundance of many farmland bird species were positivelyrelated to the number of non-cropped elements within farmland, the local mixture of annual crop and grassfields, and the variety of field types. The above positive associations were strongest in open landscapes.There was a clear indication that the more intensively farmed areas across the region provided habitat forfewer bird species and individuals. The difference could partly be explained by the more heterogeneouslandscape and field areas in the latter. Within homogenous arable fields intensification of field managementwas reflected in a tangible decrease in farmland bird abundance, especially in species in need of edgestructures.Based on the interviews in Estonia and Finland I explored farmers’ interest in and knowledge offarmland wildlife, their understanding of the concept of biodiversity, and awareness of the potential causesbehind declines of farmland birds. Many farmers viewed biodiversity from a narrow perspective oftenexcluding species directly related to farming. In Finland farmers expressed concern about the decline incommon farmland species, but Estonian farmers did not, which might be related to the fact that these speciesare still very common. In both countries farmers rated intensification of agriculture as the major drivingforce behind farmland bird declines. The expressed interest in wildlife positively correlated with willingnessto undertake wildlife-friendly measures. Only farmers with agri-environment contracts targeted specificallyat biodiversity enhancement were more knowledgeable about practical on-farm activities favouring wildlife,and were more willing to employ them that the rest.The results suggest that, by contributing to simplification of the farmland structure, homogenisationof crops, and increase in intensity of field use EU agricultural policies will have a detrimental effect onfarmland bird populations in Eastern Europe. Farmers are on the whole positive to the idea of supportingwildlife in the fields, and are concerned about its decline, but they require payments to offset their incomeloss and extra work. Biodiversity conservation should be better integrated into the agri-environmentprogrammes if it to serve as awareness tool for farmers. I argue that with a foreseen tripling of cereal yieldsacross the region, the EU Council’s Göteborg target of slowing biodiversity decline by 2010 may not berealistic unless considerable improvements are made into the EU agricultural policy for the region.

Indicators for biodiversity in agricultural landscapes: a pan‐European study

Summary In many European agricultural landscapes, species richness is declining considerably. Studies performed at a very large spatial scale are helpful in understanding the reasons for this decline and as a basis for guiding policy. In a unique, large‐scale study of 25 agricultural landscapes in seven European countries, we investigated relationships between species richness in several taxa, and the links between biodiversity and landscape structure and management. We estimated the total species richness of vascular plants, birds and five arthropod groups in each 16‐km2 landscape, and recorded various measures of both landscape structure and intensity of agricultural land use. We studied correlations between taxonomic groups and the effects of landscape and land‐use parameters on the number of species in different taxonomic groups. Our statistical approach also accounted for regional variation in species richness unrelated to landscape or land‐use factors. The results reveal strong geographical trends in species richness in all taxonomic groups. No single species group emerged as a good predictor of all other species groups. Species richness of all groups increased with the area of semi‐natural habitats in the landscape. Species richness of birds and vascular plants was negatively associated with fertilizer use. Synthesis and applications. We conclude that indicator taxa are unlikely to provide an effective means of predicting biodiversity at a large spatial scale, especially where there is large biogeographical variation in species richness. However, a small list of landscape and land‐use parameters can be used in agricultural landscapes to infer large‐scale patterns of species richness. Our results suggest that to halt the loss of biodiversity in these landscapes, it is important to preserve and, if possible, increase the area of semi‐natural habitat.

A comprehensive study of nutrient losses, soil properties and groundwater concentrations in a degraded peatland used as an intensive meadow – Implications for re-wetting

Summary Most of the once ecologically valuable and widespread peatlands in Western Europe as well as in Mecklenburg-Vorpommern (North-Eastern Germany) have been drained in the course of the intensification of agricultural land use. Peat degradation and mineralisation frequently caused high nitrate–nitrogen ( NO 3 - – N ) losses, while re-wetting may lead to elevated phosphorus concentrations in the porewater. High concentrations of NO 3 - – N and other solutes in a ditch draining a catchment (85 ha) dominated by degraded peatland under intensive grassland use gave reason to investigate the relationship between the spatial and temporal variability of the shallow groundwater quality on the one hand and soil properties, topography and hydrological dynamics on the other hand. Therefore, in addition to the ditch, three transects of dipwells were sampled and soil samples were taken along the transects at a high spatial resolution. Soil organic carbon Corg and total nitrogen Nt contents varied considerably from 0.8% to 40.9% and 0.08% to 2.87%, respectively. A trend surface analysis (TSA) of these soil properties showed a strong trend depending on the ground elevation and the distance to the adjacent drainage ditch, reflecting both a transition from mineral to organic soils and differences in peat formation and degradation connected to the topography and, consequently, to the depth to the groundwater table. Semivariogram analysis was performed using the normally distributed residuals of the TSA and showed for each transect a strong spatial dependence and short (5–26 m) ranges. If possible, soil sampling in peatlands should be conducted at short distance sampling intervals. The patterns of groundwater solute concentrations were complex. They were spatially and temporally very variable between as well as within the transects, thus proving that a few groundwater samples are insufficient for a representative characterisation of the peatland status and for an evaluation of possible environmental impacts or potential consequences of re-wetting. Groundwater concentrations ranged from 0 to 65.4 mg l−1 NO 3 - – N and 0–1.95 mg l−1 Pt, while during the same period, ditch water concentrations of 0–15.9 mg l−1 NO 3 - – N and 0.05 to 0.44 mg l−1 Pt, respectively, were measured. Factor analysis of groundwater concentrations, topographical data, hydrological conditions and soil properties led to the identification of five factors explaining up to 80% of the observed variance of the data: (i) topography and soil chemical properties, (ii) biogeochemical processes, (iii) drainage effects, (iv) climatic effects and (v) dilution effects.