Grassland Management Intensity Research Articles

Assessing landscape-level effects of permanent grassland management and landscape configuration on open-land butterflies based on national monitoring data

Halting and reversing the ongoing insect decline requires in-depth knowledge on key drivers. Due to their sensitivity to habitat quality, butterflies are valuable indicators for grassland management intensity, including mowing. However, most studies examining mowing regime impacts on butterflies are limited to small spatial extents. Here, we tested the potential of citizen science butterfly monitoring data for assessing landscape-level effects of mowing regimes (number of mowing events and timing of the first event) and edge density (density of boundaries between different land-cover types) on butterfly richness, abundance, and community composition. We used generalised linear mixed-effects models to relate nationwide data from the German Butterfly Monitoring Scheme (DEBMS) to high-resolution satellite imagery on mowing events in permanent grasslands (grasslands excluded from crop rotation). As butterfly transects may not consistently be located within grasslands, we ran our models for different thresholds from 0 to 50%, representing increasing shares of the transect route situated within permanent grasslands (10% intervals). We did not find significant associations between mowing regimes and butterflies when focussing on species richness and abundance of all species inhabiting open land. However, we found strong positive associations of delayed mowing with the abundance of grassland specialists with increasing grassland shares per transect. Further, we found negative associations of delayed mowing with the annual number of generations and of more frequent mowing with the abundance of specialists, depending on the share of grassland per transect. Edge density had a positive association with species richness and abundance of species inhabiting open land, as well as abundance of grassland indicator species and grassland specialists in landscapes with a low grassland share per transect. Our findings underscore the importance of low-intensity managed permanent grasslands at the landscape scale for specialised butterflies. Additionally, we highlight the importance of a high density of boundaries for open-land and specialised butterflies, particularly in landscapes with highly fragmented permanent grasslands. To improve future analyses of grassland management impacts, we recommend expanding DEBMS monitoring sites to cover a larger grassland management intensity gradient and to place more transects within grasslands.

Effect of nature protection and management of grassland on biodiversity – Case from big flooded river valley (NE Poland)

Agriculturally used meadows are habitats whose biodiversity depends on anthropogenic disturbances such as fertilization or mowing. Intensified agricultural practices (too frequent mowing, use of mineral fertilizers and insecticides) lead to declines in the abundance and species diversity of the biota inhabiting them. The intensification of agricultural production in north-eastern Poland relates primarily to the increase in cattle numbers and the intensification of grassland management, but many areas were included in Natura 2000 network. Our study was aimed at indicating the impact of diverse use of meadows on the species richness and diversity of invertebrates, amphibians, and birds in the grasslands of Narew river valley, Special Bird Protection Area, where the intensification of grassland use was noted in the last decades, and part of the meadows was included in the agri-environmental program. The agri-environmental program is a very good tool for the protection of grassland biotic diversity. The highest taxonomic richness and diversity of the studied animal groups were found in meadows included in these programs with extensive use, while the lowest was in the over- and intensively used meadows fertilized with mineral fertilizers and liquid manure. Only the meadows in the agri-environment program were inhabited by the fire-bellied toad and the tree frog - amphibians from Annex IV of the Habitats Directive. The number of breeding bird species globally threatened (IUCN Red List), listed in Annex I of the EU Birds Directive, and with negative population trend in Europe (SPEC1–3) was highest in meadows included in EU conservation programs. The main factors reducing biotic diversity in the grassland of flooded river valley were the high number of grassland mowing per season, intensive fertilization, especially with liquid manure, the great distance of meadows to the river, low soil humidity, and low share of shrubs and trees in the meadows border zone.

Natural grassland conversion to cultivated pastures increases soil microbial niche specialization with consequences for ecological processes

The conversion of natural grasslands to cultivated pastures has a profound effect on the soil habitat conditions, influencing the proportion of soil specialist and generalist microbes, with consequences for the assembly of microbial communities. This often leads to the homogenization of the microbial community and thus favoring stochastic assembly processes. However, there is still a gap in understanding the effect of conversion from natural grasslands to cultivated pastures on soil microbial ecological processes. Therefore, we aimed to investigate the assembly patterns of microbial communities and evaluate the ecological models for generalists and specialist microbes along a grassland management intensification gradient. Through 16S rRNA amplicon sequencing, we found that the conversion of natural grasslands to cultivated pastures has increased the number of microbial specialists, resulting in stochastic assembly processes due to the decrease in plant diversity. Moreover, the ecological processes governing the assembly of microbial communities were affected by soil and vegetation management. The perennial pasture was more affected by homogenizing selection, owing to the lower plant diversity and uniform plant covering and root development. We have found that the generalists in the grasslands are shaped by niche-based models, while the specialists in natural grasslands are more stochastic in nature. For improved pastures, we have found that lognormal and preemption models are more predominant, suggesting that homogenizing dispersal is more predominant than variable selection. We highlight it is essential to comprehend these assembly models and ecological processes to ensure plant-microbe supporting and provisioning ecosystem services for cattle, and humans while establishing management strategies and conservation policy priorities.

Grassland management intensification affects the soil fauna in a subtropical highland

AbstractThe conversion of natural grasslands to cultivated pastures can have a significant impact on the composition and structure of soil macro‐ and mesofauna groups, compromising the resilience of these organisms and the ecosystem services they provide. We studied the responses of these groups to increasing levels of soil disturbance across a gradient of four land management practices: Natural grassland (NG), Improved‐natural grassland (IG), Perennial‐cultivated pasture (PP), and Annual‐cultivated pasture (AP). The NG area had a higher abundance of macrofauna, greater dominance of certain groups, particularly Isoptera, and a lower abundance of mesofauna. On the other hand, the IG area had a higher abundance and diversity of macro‐ and mesofauna, with a lower dominance of specific groups. The PP area had a higher abundance of Coleoptera, Oligochaeta, and Hemiptera, whereas the AP area, despite soil disturbance, showed a higher abundance of mesofauna, particularly mites, Collembola, and Enchytraeidae, but lower diversity. Different grassland management practices have significantly altered the composition and structure of macro‐ and mesofauna groups, resulting in high dissimilarity between communities. We recommend IG as a more productive and sustainable alternative to the total replacement of natural vegetation (NG) with intensified converted pastures (PP and AP), as it maintains soil fauna diversity and ecosystem services.

Effectiveness of flowers strips on insect’s restoration in intensive grassland

Intensification of grassland management causes a decrease in insect diversity. However, the mowing also causes substantial damage to insects if too homogeneously applied, especially for insect species with specialized needs. The overarching goal of the study was to investigate the restorative effect of flower strips on adjoining intensive grasslands to preserve and restore native grassland insect diversity. In 2020–2021, we analyzed how flower strips enhance Heteroptera, syrphids and butterflies diversity in adjoining intensive grassland compared to separated intensive (control) and extensive grasslands within the Austrian alpine range. Heteroptera and syrphid species richness and syrphid abundance were significantly higher in flower strips compared to other studied grasslands. However, butterfly abundance and species richness were significantly higher in extensive grasslands compared to flower strips. Heteroptera species assemblages in extensive grasslands were significantly different between flower strips, intensive and control grasslands. Further, Heteroptera abundance and species richness increased with an increase in flower cover and vegetation height. Similarly, syrphid abundance and species richness significantly increased with flower cover but decreased with vegetation structure. Butterfly abundance increased with plant species, however, species richness decreased with vegetation height. Altogether, 39.4% Heteroptera, 39.7% syrphid and 51.2% butterfly species were similar between flower strips and adjoining intensive grasslands. Restoring biodiversity in intensive grasslands represents a real conservation challenge. Flower strips seem most effective to enhance syrphid abundance that showed potential spill-over effect to intensive grasslands. Beside this, flower strips restorative effect is taxa specific. Overall, restoration of insect diversity is a relatively slow process, in which colonization by each insect group is not only limited by local vegetation conditions but is also affected by the presence, distance, and connection to source populations. However, maybe after more than two years intensive grassland is more promoted by adjoining flower strips. The results of the present study could be used to push for more active implementation of flower rich habitats as supplement areas as well as for the conservation of extensively managed grasslands. This will allow both, productive agricultural land use while maintaining and promoting insect habitats, and increase in species diversity within a heterogeneous landscape.

Invertebrate abundance increases with vegetation productivity across natural and agricultural wader breeding habitats in Europe

Grassland breeding waders have been steadily declining across Europe. Recent studies indicating a dramatic decline in grassland invertebrates' abundance and biomass, the key food of most grassland wader chicks, suggest a likely driver of the demise of waders. While agricultural intensification is generally inferred as the main cause for arthropod decline there is surprisingly little information on the relationship between land use intensity and total arthropod abundance in grasslands. Here, we explored those relationships across several key wader breeding habitats by surveying ground-active, aerial and soil-dwelling invertebrate communities in five European countries that range from natural undisturbed bogs to intensively managed grasslands. Using maximum vegetation growth and soil moisture content we investigated how they shape the size of the invertebrate community within and across different countries. We found predominantly positive relationships between grassland invertebrate abundance, biomass and body weight with increasing vegetation growth and soil moisture. Maximum vegetation growth was strongly positively related to ground-active invertebrate abundance and biomass and abundance of soil dwelling invertebrates (mainly earthworms). Body weight of aerial invertebrates furthermore increased with increasing maximum vegetation growth. Our results provide little support for the hypothesis that agricultural practices associated with intensification of grassland management result in an abundance decline of invertebrate prey for wader chicks. Conservation practices aiming to enhance wader chick survival require a careful balancing act between maintaining habitat productivity to secure high prey abundance, and keeping productivity low enough to maintain open swards that do not need to be cut before chicks have fledged.

Direct and plant community mediated effects of management intensity on annual nutrient leaching risk in temperate grasslands

Grassland management intensity influences nutrient cycling both directly, by changing nutrient inputs and outputs from the ecosystem, and indirectly, by altering the nutrient content, and the diversity and functional composition of plant and microbial communities. However, the relative importance of these direct and indirect processes for the leaching of multiple nutrients is poorly studied. We measured the annual leaching of nitrate, ammonium, phosphate and sulphate at a depth of 10 cm in 150 temperate managed grasslands using a resin method. Using Structural Equation Modeling, we distinguished between various direct and indirect effects of management intensity (i.e. grazing and fertilization) on nutrient leaching. We found that management intensity was positively associated with nitrate, ammonium and phosphate leaching risk both directly (i.e. via increased nutrient inputs) and indirectly, by changing the stoichiometry of soils, plants and microbes. In contrast, sulphate leaching risk was negatively associated with management intensity, presumably due to increased outputs with mowing and grazing. In addition, management intensification shifted plant communities towards an exploitative functional composition (characterized by high tissue turnover rates) and, thus, further promoted the leaching risk of inorganic nitrogen. Plant species richness was associated with lower inorganic nitrogen leaching risk, but most of its effects were mediated by stoichiometry and plant community functional traits. Maintaining and restoring diverse plant communities may therefore mitigate the increased leaching risk that management intensity imposes upon grasslands.

Using deep learning to classify grassland management intensity in ground-level photographs for more automated production of satellite land use maps

Collecting accurate reference data for training and validating remotely sensed land use/land cover (LULC) maps is important. Financial and logistical constraints on projects mean it may not be possible to collect field data. Automated photo recognition methods using deep learning are increasingly being used for mapping land cover (the physical surface at a location). Their use in mapping land use (how the surface is used) is less well developed. This study explores an approach of using geotagged ground-level photographs to identify management intensity on agricultural grasslands. Management intensity on grasslands has implications for soil and water quality, biodiversity and habitat loss, and carbon fluxes. Uncertainty in the level of management intensity occurring at field scale is a source of error in greenhouse gas emission estimates from grasslands. Our study uses convolutional neural networks (CNN) to automate the labelling of unseen images into three management classes (intensive, extensive, abandoned). Ground-level photographs were taken during the 2018 EUROSTAT Land Use/Coverage Area Frame Survey (LUCAS). Accuracy up to 92.8% was achieved. Predicted labels were used to train a management intensity map using Sentinel 1 and Sentinel 2 satellite imagery. Overall accuracy for a random forest (RF) classification was 84.8% (64.8% after class imbalance was accounted for). Potential improvements to both the CNN and RF models are discussed. This study demonstrates the potential of CNN for classifying grassland use from geotagged photographs as part of automated LULC mapping workflows.

A multimodality test outperforms three machine learning classifiers for identifying and mapping paddocks using time series satellite imagery

Rotational grazing in paddocks is a strong indicator of intensive grassland management. Uncertainty in the extent of grassland management intensity is a reported source of uncertainty in greenhouse gas budgeting. This article outlines a method of detecting paddock locations in Sentinel 2 satellite imagery using a statistical multimodality test. The test was compared to three machine learning algorithms (support vector machine, random forest and extreme gradient boosting). Photographic records of the Eurostat 2018 LUCAS survey were used as ground truth data to confirm the presence or absence of paddocks. The multimodality test achieved an overall accuracy of 88.4% versus the best machine learning accuracy of 82.4%. The test was also used to map paddock occurrence at a regional scale in the Republic of Ireland. Overall map accuracy was 85.7% versus validation data. The test can be applied in temperate grasslands with pre-mapped field boundaries where rotational grazing is practiced.

The rolling dung master: An ecosystem engineer beetle mobilizing soil nutrients to enhance plant growth across a grassland management intensity gradient in drylands

Dryland cattle pastures often yield sub-optimal economic returns while it intervenes with natural ecosystems functioning. Dung beetles improve soil conditions but little is known about how their functioning changes with different land management intensities. We assessed the role of the telecoprid dung beetle Canthon humectus in soil nutrient mobilization and commercial crop growth in arid grasslands with contrasting cattle managements. We set up a mesocosm experiment where we monitored dung beetle activity in containers filled with dung and soil from sites with three different cattle managements. Dung removal rates due to beetle burial activity were 10% higher than due to dehydration alone but was not affected by cattle management. After 60 days of beetle activity nitrates and ammonium levels increased significantly as compared with control pots without beetles. Additionally, we monitored corn plant growth in pots with soil with and without beetle activity. Plants significantly increased their biomass due to beetle activity in the substrate with the highest and lowest pasture management intensity. In the latter case, more biomass was allocated to shoots. The ability of C. humectus to increase soil nutrients and enhance plant growth is affected by local cattle management.

A framework for sustainable management of ecosystem services and disservices in perennial grassland agroecosystems

AbstractIncreasing demand for agricultural products is driving grassland management intensification with subsequent impacts on ecosystem services and disservices. Key questions related to grassland production as well as environmental and social concerns must be addressed to ensure sustainability. We propose a unified perspective, addressing numerous trade‐offs and synergies between grassland ecosystem services and disservices, and considering an array of ecological and human consequences associated with history and ongoing shifts in management strategies. Much of our discussion utilizes evidence from humid grasslands; however, our examples and recommendations have global implications for the future of grassland management. We characterize four categories of ecosystem services and disservices (provisioning, supporting, regulating, and cultural) provided by perennial grasslands that are extensively managed (low or no input, never cultivated) or intensively managed (high‐input, cultivated). We explore a range of potential outcomes following transition from extensive to intensive agroecosystems around the globe. Additionally, we suggest specific research priorities to better evaluate ecosystem services and disservices across management intensities. Finally, we highlight potential benefits of landscape mosaics that include grasslands across a continuum of extensive to intensive strategies.

Mowing event detection in permanent grasslands: Systematic evaluation of input features from Sentinel-1, Sentinel-2, and Landsat 8 time series

The intensity of land use and management in permanent grasslands affects both biodiversity and important ecosystem services. Comprehensive knowledge about these intensities is a crucial factor for sustainable decision-making in landscape policy. For meadows, the management intensity can be described by proxies such as the mowing frequency, usually, a higher number of cuts indicate higher intensities. Dense time series of medium resolution (10–30 m) remote sensing data are suitable for the detection of mowing events. However, existing studies revealed a general lack of consensus about the most appropriate input data set for a consistent and reliable mowing detection.We systematically evaluated the synergistic use of acquisitions from Sentinel-1, Sentinel-2, and Landsat 8 to detect the occurrence, frequency, and date of mowing events as an indicator of grassland management intensity. Dense time series of NDVI (Sentinel-2 and Landsat 8), γ0 backscatter, backscatter cross-ratio, backscatter second-order texture metrics as well as 6-day interferometric coherence (Sentinel-1) were used as input features. All possible combinations of input features were tested to train a one-dimensional convolutional neural network, which enables enhanced exploitation of the temporal domain of the data. The evaluation was conducted on 64 meadows for an overall of 257 mowing events from 2017 to 2019 in Germany.Our results revealed that the combination of input features improves the detection performance. The highest overall accuracy was reached by a combination of NDVI, backscatter cross-ratio, and interferometric coherence with an F1-Score of 0.84. The mowing frequency was predicted with a mean absolute error of 0.38 events per year, while the date of the events was missed by 3.79 days on average. NDVI time series alone mostly underperformed in comparison to optical/SAR combinations but clearly outperformed input-sets that were solely based on SAR features. The proposed model performed well for meadows with low to medium management intensities but further testing is recommended for highly intensive managed parcels.The results clearly demonstrate the additional value of fusing time series of the three present Earth observation systems that deliver a freely available global coverage of the land surface at medium resolution.

Soil bacteria respond to regional edapho-climatic conditions while soil fungi respond to management intensity in grasslands along a European transect

Soil microbial community structure is determined by environmental conditions and influenced by other factors, such as the intensity of the land use management. Studies addressing the effect of environmental factors and management on grassland soil microbial communities at the continental scale are missing, and the wide range of ecosystem services provided by these ecosystems are thus also wanting. To address this knowledge gap, this study presents data on grassland soil microbial communities along a pan-European agro-ecological gradient. The transect included five geographical locations (Sweden, Germany, Switzerland, Portugal mainland, Portugal Azores). At each location, soils were collected in two regions characterized by favourable and less favourable conditions for plant growth. In each of these ten regions, grasslands along a gradient of management intensity were selected, i.e. grassland under intensive, less intensive and extensive management. Phospholipid fatty acid analysis (PLFA) was used to characterize the microbial community structure (PLFA pattern) in relation to climatic and soil properties. Over the whole geographical range, the environmental properties determined the soil microbial community structure. In Sweden and Switzerland, the regional growth conditions had the strongest influence on the soil microbial communities, while in Germany, Portugal mainland and Azores the management intensity was more important. Splitting up this whole community response into individual groups reveals that, in general, saprotrophic fungal biomarkers were highest in extensively managed grasslands while bacterial biomarkers differed mainly between the regions. We conclude that at the transect level, climate and soil properties were the most important factors influencing soil bacterial community structure, while soil fungal groups were more responsive to grassland management intensity. Overall agricultural sustainability could benefit from informed soil health promoting management practices, and this study contributes to such knowledge, showing the importance of management for the soil microbial biomass and community structure.

Different management practices influence growth of small plants in species‐rich hay meadows through shading

AbstractAimsThe intensification of grassland management can cause a loss of biodiversity via alteration of the structure and micro‐environmental conditions within the sward. The species richness of hay meadows protected within the Natura 2000 network is often endangered by high levels of fertilisation and relatedly, increased cutting frequency, which leads to decreased light availability for small plants and seedlings at ground level. The purpose of this study is to analyse how management practices and the interaction of fertilisation and cutting regime affect light distribution in grassland canopies as well as the growth of small plants.LocationSouth Germany.MethodsThis was investigated by measuring the photosynthetically active radiation (PAR) and dry matter yield (DMY) of the first growth cycle over 2 years at two sites of a 5‐year‐old hay meadow trial. To calculate the relative light intensity, PAR was measured above the canopy and at ground level. Two factors, fertilisation (none, PK, NPK) and date of first cut (based on phenological stages), were manipulated.ResultsOur results show that the date of the first cut had no influence on light availability during the first growth cycle, whereas fertilisation decreased light availability for small plants due to a denser canopy. Fertilisation increased the DMY of the first growth cycle significantly. We show that NPK fertilisation (35 kg N, 35 kg P2O5 and 120 kg K2O ha−1 a−1) decreased both the number and proportion of small plant species.ConclusionNPK fertilisation can lead to a loss of biodiversity. These results are of relevance for the improvement and management of species‐rich hay meadows. Because of its effect on competition for light, the supply of plant‐available nitrogen is a key driver in obtaining or restoring biodiversity in species‐rich hay meadows. Therefore, careful site‐adapted fertilisation is a basic requirement in maintaining the ecological value of grassland.

Grassland intensification dramatically impacts grasshoppers: Experimental evidence for direct and indirect effects of fertilisation and irrigation

European mountain hay meadows are hosting an exceptionally rich biodiversity. They are currently threatened by both land abandonment and farming intensification via aerial irrigation and slurry application. The consequences of mountain grassland intensification on arthropods are still poorly documented, which is a serious handicap to proposing ecologically-friendly management guidance. Six experimental treatments mimicking a gradient of management intensity (including irrigation, fertilisation and various combinations thereof) were initiated in 2010 at twelve montane and subalpine Swiss meadow sites. In 2013, we sampled orthopterans to assess the influence of management practice on that taxonomic group. In parallel, the changes in vegetation height and ambient temperature (at 10 cm above ground level) induced by the intensification process were quantified in order to better appraise the underlying mechanisms. Intensification had a negative impact on Caelifera (grasshoppers), with decreases in densities and species richness reaching as much as 70% and 50%, respectively, in the most intensively managed treatment plots. Intensification furthermore led to a marked increase in mean vegetation height and a cooling of ambient temperature by up to 4.2 °C. Such microhabitat and microclimate alterations are likely to affect Caelifera development, in particular thermophilous species. In contrast, Ensifera (bushcrickets) densities and species richness showed no significant response to our experimental manipulations. Finally, the application of irrigation by sprinklers alone had limited impact on both orthopterans and meadow microclimate. We conclude that orthopterans, in particular Caelifera, are fairly sensitive to grassland management intensification: fertilisation should be avoided in focal areas for biodiversity conservation.

Modeling the effects of grassland management intensity on biodiversity

Modeling the effects of grassland management intensity on biodiversity

Modeling the effects of grassland management intensity on biodiversity.

A growing food demand and advanced agricultural techniques increasingly affect farmland ecosystems, threatening invertebrate populations with cascading effects along the food chain upon insectivorous vertebrates. Supporting farmland biodiversity thus optimally requires the delineation of species hotspots at multiple trophic levels to prioritize conservation management. The goal of this study was to investigate the links between grassland management intensity and orthopteran density at the field scale and to upscale this information to the landscape in order to guide management action at landscape scale. More specifically, we investigated the relationships between grassland management intensity, floral indicator species, and orthopteran abundance in grasslands with different land use in the SW Swiss Alps. Field vegetation surveys of indicator plant species were used to generate a management intensity proxy, to which field assessments of orthopterans were related. Orthopteran abundance showed a hump‐shaped response to management intensity, with low values in intensified, nutrient‐rich grasslands and in nutrient‐poor, xeric grasslands, while it peaked in middle‐intensity grasslands. Combined with remote‐sensed data about grassland gross primary productivity, the above proxy was used to build landscape‐wide, spatially explicit projections of the potential distribution of orthopteran‐rich grasslands as possible foraging grounds for insectivorous vertebrates. This spatially explicit multitrophic approach enables the delineation of focal farmland areas in order to prioritize conservation action.

Remote Sensing of Grassland Production and Management—A Review

Grasslands cover one third of the earth’s terrestrial surface and are mainly used for livestock production. The usage type, use intensity and condition of grasslands are often unclear. Remote sensing enables the analysis of grassland production and management on large spatial scales and with high temporal resolution. Despite growing numbers of studies in the field, remote sensing applications in grassland biomes are underrepresented in literature and less streamlined compared to other vegetation types. By reviewing articles within research on satellite-based remote sensing of grassland production traits and management, we describe and evaluate methods and results and reveal spatial and temporal patterns of existing work. In addition, we highlight research gaps and suggest research opportunities. The focus is on managed grasslands and pastures and special emphasize is given to the assessment of studies on grazing intensity and mowing detection based on earth observation data. Grazing and mowing highly influence the production and ecology of grassland and are major grassland management types. In total, 253 research articles were reviewed. The majority of these studies focused on grassland production traits and only 80 articles were about grassland management and use intensity. While the remote sensing-based analysis of grassland production heavily relied on empirical relationships between ground-truth and satellite data or radiation transfer models, the used methods to detect and investigate grassland management differed. In addition, this review identified that studies on grassland production traits with satellite data often lacked including spatial management information into the analyses. Studies focusing on grassland management and use intensity mostly investigated rather small study areas with homogeneous intensity levels among the grassland parcels. Combining grassland production estimations with management information, while accounting for the variability among grasslands, is recommended to facilitate the development of large-scale continuous monitoring and remote sensing grassland products, which have been rare thus far.

Spatial monitoring of grassland management using multi-temporal satellite imagery

Abstract Spatial monitoring of grassland management is crucial for ecosystem assessment and the establishment of sustainable agriculture. Switzerland is covered by large areas of small structured grassland parcels differing in management practices and use intensities, making the mapping of grassland management challenging. We present a monitoring tool to map grassland management, distinguishing between mowing- and grazing practice, and between different use intensities for Swiss agroecosystems. By analyzing pixelwise spectral time series of 2015, derived from satellite imagery of the Landsat archive, we estimated the number of management events and biomass productivity. Both estimates were used to map classes of dominant management practices and use intensities following a stepwise clustering approach. The grassland management (GM) classes were evaluated relative to established spectral and topographical patterns of grassland use intensity, and in terms of spatial conformity with available regional land use data. The GM classes were also analyzed with respect to management related vegetation plot data on species diversity, as well as on indicator values for nutrient supply and management tolerance. The stepwise clustering gave three use intensity classes for each dominant management practice of grazing (pasture) and mowing (meadow). Use intensity was higher for meadows than pastures with a distinct intensity gradient for each grassland practice. The GM classes reproduced established spectral and topographical patterns of grassland use intensity, indicated by increased standard deviations (SD) of spectral time series profiles (e.g. mean SD of 0.048 for pastures and 0.054 for meadows) and lower slopes (e.g. mean slopes of 10° for pastures and 7° for meadows). The averaged spatial conformity of the GM classes with a cantonal land use map was 82% for meadows and 97% for pastures. The GM classes spatially matched with land use patterns of three subregions, e.g. with an areal proportion of 73% pasture classes for a subregion dominated by grazing. Moreover, the GM classes reproduced established vegetation patterns of grassland use intensity along the GM intensity gradient, showing a mean decrease in species richness (33%), as well as a mean increase in indicator values for nutrient supply (5%), grazing tolerance (4%), and mowing tolerance (6%).

Effects of grassland management on plant nitrogen use efficiency (NUE): Evidence from a long-term experiment

Grassland management intensification can greatly influence nitrogen (N) dynamics between aboveground and belowground compartments mainly because of the large amount of available N forms, which are repeatedly added to soils. A better understanding of how chronic fertilisation might affect N use efficiency (NUE) in plants can contribute to reducing N losses from soils and improve the sustainability of managed grasslands. Here we address how NUE might be affected by (1) the addition of key nutrients (e.g. N, P, K, Mg) in different combinations, (2) grazing by rabbits, and (3) liming (i.e. CaCO3 applications) in a 22-year-old permanent grassland experiment established in Berkshire, UK, in 1991. We first calculate seven different NUE indexes, which are known to respond either to changes in soil N availability (i.e. endogenous N inputs from soil N mineralization processes) or to exogenous N inputs (i.e. synthetic N fertiliser). We found that plant NUE calculated as plant biomass produced per unit of N acquired significantly decreased under the chronic addition of multiple nutrients (NPKMg) and was even lower under N-only applications. Most NUE indexes significantly decreased under grazing but greatly increased under liming applications. We found evidence that NUE indexes, which accounted for endogenous N sources decreased at increased rates of soil N mineralization. Finally, we found no significant relationships between any of the NUE indexes and estimates of soil N losses (Mg N ha−1) or N retention in soils (i.e. units of soil N retained per unit of N added) calculated from changes in net soil N budget over 22 years. Our study carried out on relatively acidic sandy soils suggests how liming applications in combination with low levels of multi-nutrient additions (NPKMg) can significantly improve plant biomass production per unit of N added thus contributing to enhance the sustainability of managed grassland ecosystems.