The growing replacement of native vegetation by forest plantations is considered a global threat to biodiversity. Significant variation in biotic communities among stands with similar management suggests that previous land use might have an effect on the capacity of forest plantations to harbor native species. The goal of our study was to determine the effect of land-use history on the biodiversity currently present in pine plantations in the coastal range of Central Chile. In particular, we hypothesized that plantations that directly replaced native forests should have higher diversity of plants and birds than plantations that were established in agricultural areas. We also expected that plantations of higher number of rotations should have fewer habitat-specialists and more generalists/exotics, reflecting a process of biotic homogenization. Using aerial photographs and satellite images encompassing a period of six decades, we classified 108 4-ha sampling units into native forests, and mature (17-20 year) pine plantations of first, second, and third rotation, of either forest or agricultural origin. At each site, we collected data on the abundance and richness of diurnal birds and understory plants, and analyzed their behavior in relation to the land-use history using Generalized Linear Models (GLMs). Also, we evaluated dissimilarity of communities of each pine plantation "treatment" to assess the occurrence of biotic homogenization. As predicted, pine plantations that directly replaced native forests had a higher abundance of forest specialists and less abundance of exotics and generalists than plantations of agricultural origin. In contrast, the number of rotations of pine plantations not only did not affect negatively the diversity and abundance of forest specialist species, but the models showed some signs of naturalization in the studied systems over time, such as the increase in the abundance of native herbs and a reduction in the abundance of their exotic counterparts. These results agree with the lack of evidence for a decrease in the dissimilarity of biotic communities in plantations with time, suggesting that the management of pine plantations in Central Chile is not promoting biotic homogenization, beyond the impact of the initial stages of land use change. | Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) CONICYT FONDECYT 1080463 1120314 Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) 21170437 Vicepresidency of Academic Affairs of the University of Chile School of Forest Science and Nature Conservation

Climate change and biodiversity loss are amongst the most pressing environmental issues internationally, with far-reaching impacts that place natural and semi-natural habitats at ever greater risk of degradation. My project explores the effects of land-use on plant biodiversity in semi-natural grazing lands using datasets covering Sweden’s southernmost region, Scania. Comparative analyses were performed using biodiversity measures and a number of landscape variables. The measures of biodiversity in terms of plant species richness were calculated using a grazing land inventory subset with records from the latest years. These measures were correlated with landscape variables, relating to hydrology and vegetation phenology. Such variables include a Wetness Index and Plant Phenology Index, computed using recent remotely sensed data, namely Sentinel-2 time series data. Land cover data was processed to cluster the study sites into distinct land cover groups which facilitated further correlation analysis between plant biodiversity and the landscape variables. These variables were also analysed at two spatial scales, i.e. at the extent of both the grazing lands and their 1 km buffer zones. | Grazing land has been described as a biodiversity-rich habitat, and modifying agricultural practices which sustain both fodder production for grazing livestock and the grazing activity itself could disturb the ecosystems in such semi-natural landscapes. Livestock grazing is extensive in Scania and other Swedish regions, and significant changes to this practice could negatively impact biodiversity. The relevance of land-use within semi-natural habitats that have an agricultural purpose is important to study, given the risk that such grazing lands are lost to cropland or other land-use whenever grazing practices are abandoned. The potential for biodiversity loss in these rural settings is known to be significant with increasing land-use change. Finding out if any landscape variables can be associated with the plant biodiversity found in these sites is useful for revealing which, if any, land-use types and/or agricultural practices apart from the grazing itself can be associated to grassland biodiversity. My project explores the effects of land-use on plant biodiversity in semi-natural grazing lands using datasets covering Sweden’s southernmost region, Scania. Comparative analyses were performed using biodiversity measures and a number of landscape variables. The measures of biodiversity in terms of plant species richness were calculated using a grazing land inventory subset with records from the latest years. These measures were correlated with landscape variables, relating to hydrology and vegetation phenology. Such variables include a Wetness Index and Plant Phenology Index, computed using recent remotely sensed data, namely Sentinel-2 satellite data. Land cover data was processed to cluster the study sites into distinct land cover groups which facilitated further correlation analysis between plant biodiversity and the landscape variables. These variables were also analysed at two spatial scales, i.e. at the extent of both the grazing lands and their 1 km buffer zones. Following the use of standard biodiversity metrics and multiple landscape descriptors, the importance of present land-use for plant biodiversity patterns in Scanian grazing lands could not be established. Whilst avoiding unnecessary complexity in my attempt to relate land-use with biodiversity, the results and implications are in agreement with recent literature suggesting that rather than the present land-use, the grassland plant biodiversity is due to historical land-use to a greater extent. Historical land-use remains a valid explanation of present-day plant richness in grazing lands as most land-use effects cannot be associated with biodiversity.

Land-use intensification is a major driver of biodiversity loss. However, understanding how different components of land use drive biodiversity loss requires the investigation of multiple trophic levels across spatial scales. Using data from 150 agricultural grasslands in central Europe, we assess the influence of multiple components of local- and landscape-level land use on more than 4,000 above- and belowground taxa, spanning 20 trophic groups. Plot-level land-use intensity is strongly and negatively associated with aboveground trophic groups, but positively or not associated with belowground trophic groups. Meanwhile, both above- and belowground trophic groups respond to landscape-level land use, but to different drivers: aboveground diversity of grasslands is promoted by diverse surrounding land-cover, while belowground diversity is positively related to a high permanent forest cover in the surrounding landscape. These results highlight a role of landscape-level land use in shaping belowground communities, and suggest that revised agroecosystem management strategies are needed to conserve whole-ecosystem biodiversity.

Land-use intensification is a major driver of biodiversity loss. However, understanding how different components of land use drive biodiversity loss requires the investigation of multiple trophic levels across spatial scales. Using data from 150 agricultural grasslands in central Europe, we assess the influence of multiple components of local- and landscape-level land use on more than 4,000 above- and belowground taxa, spanning 20 trophic groups. Plotlevel land-use intensity is strongly and negatively associated with aboveground trophic groups, but positively or not associated with belowground trophic groups. Meanwhile, both above- and belowground trophic groups respond to landscape-level land use, but to different drivers: aboveground diversity of grasslands is promoted by diverse surrounding land-cover, while belowground diversity is positively related to a high permanent forest cover in the surrounding landscape. These results highlight a role of landscape-level land use in shaping belowground communities, and suggest that revised agroecosystem management strategies are needed to conserve whole-ecosystem biodiversity

Changes in climate and land use are major drivers of biodiversity loss. These drivers likely interact and their mutual effects alter biodiversity. These interaction mechanisms are rarely considered in biodiversity assessments, as only the combined individual effects are reported. In this study, we explored interaction effects from mechanisms that potentially affect biodiversity under climate change. These mechanisms entail that climate-change effects on, for example, species abundance and species’ range shifts depend on land-use change. Similarly, land-use change impacts are contingent on climate change. We explored interaction effects from four mechanisms and projected their consequences on biodiversity. These interactions arise if species adapted to modified landscapes (e.g. cropland) differ in their sensitivity to climate change from species adapted to natural landscapes. We verified these interaction effects by performing a systematic literature review and meta-analysis of 42 bioclimatic studies (with different increases in global mean temperature) on species distributions in landscapes with varying cropland levels. We used the Fraction of Remaining Species as the effect-size metric in this meta-analysis. The influence of global mean temperature increase on FRS did not significantly change with different cropland levels. This finding excluded interaction effects between climate and landscapes that are modified by other land uses than cropping. Although we only assessed coarse climate and land-use patterns, global mean temperature increase was a good, significant model predictor for biodiversity decline. This emphasizes the need to analyse interactions between land-use and climate-change effects on biodiversity simultaneously in other modified landscapes. Such analyses should also integrate other conditions, such as spatial location, adaptive capacity and time lags. Understanding all these interaction mechanisms and other conditions will help to better project future biodiversity trends and to develop coping strategies for biodiversity conservation.

Land use change (LUC) is the leading cause of biodiversity loss worldwide. However, the global understanding of LUC’s impact on biodiversity is mainly based on comparisons of land use endpoints (habitat vs non-habitat) in forest ecosystems. Hence, it may not generalise to savannas, which are ecologically distinct from forests, as they are inherently patchy, and disturbance adapted. Endpoint comparisons also cannot inform the management of intermediate mosaic landscapes. We aim to address these gaps by investigating speciesand community-level responses of mammals and trees along a gradient of small scale agricultural expansion in the miombo woodlands of northern Mozambique. Thus, the case study represents the most common pathway of LUC and biodiversity change in the world’s largest savanna. Tree abundance, mammal occupancy, and tree- and mammal-species richness showed a non-linear relationship with agricultural expansion (characterised by the Land Division Index, LDI). These occurrence and diversity metrics increased at intermediate LDI (0.3 to 0.7), started decreasing beyond LDI>0.7, and underwent high levels of decline at extreme levels of agricultural expansion (LDI>0.9). Despite similarities in species richness responses, the two taxonomic groups showed contrasting β-diversity patterns in response to increasing LDI: increased dissimilarity among tree communities (heterogenisation) and high similarity among mammals (homogenisation). Our analysis along a gradient of landscape-scale land use intensifcation allows a novel understanding of the impacts of diferent levels of land conversion, which can help guide land use and restoration policy. Biodiversity loss in this miombo landscape was lower than would be inferred from existing global syntheses of biodiversity-land use relations for Africa or the tropics, probably because such syntheses take a fully converted landscape as the endpoint. As, currently, most African savanna landscapes are a mosaic of savanna habitats and small scale agriculture, biodiversity loss is probably lower than in current global estimates, albeit with a trend towards further conversion. However, at extreme levels of land use change (LDI>0.9 or<15% habitat cover) miombo biodiversity appears to be more sensitive to LUC than inferred from the meta-analyses. To mitigate the worst efects of land use on biodiversity, our results suggest that miombo landscapes should retain>25% habitat cover and avoid LDI>0.75—after which species richness of both groups begin to decline. Our fndings indicate that tree diversity may be easier to restore from natural restoration than mammal diversity, which became spatially homogeneous.

Evidence from experimental and established grasslands indicates that plant biodiversity can modify the water cycle. One suspected mechanism behind this is a higher infiltration capacity (νB) and hydraulic conductivity (K) of the soil on species‐rich grasslands. However, in established and agriculturally managed grasslands, biodiversity effects cannot be studied independent of land‐use effects. Therefore, we investigated in established grassland systems, how land‐use intensity and associated biodiversity of plants and soil animals affect νB and K at and close to saturation. On 50 grassland plots along a land‐use intensity gradient in the Biodiversity Exploratory Schwäbische Alb, Germany, we measured νB with a hood infiltrometer at several matrix potentials and calculated the saturated and unsaturated K. We statistically analyzed the relationship between νB or K and land‐use information (e.g. fertilizing intensity), abiotic (e.g. soil texture), and biotic data (e.g. plant species richness, earthworm abundance). Land‐use intensity decreased and plant species richness increased νB and K, while the direction of the effects of soil animals was inconsistent. The effect of land‐use intensity on νB and K was mainly attributable to its negative effect on plant species richness. Our results demonstrate that plant species richness was a better predictor of νB and K at and close to saturation than land‐use intensity or soil physical properties in the established grassland systems of the Schwäbische Alb.

Agricultural production provides food, feed, and renewable energy, generates economic profits, and contributes to social welfare in many ways. However, intensive farming is one of the biggest threats to biodiversity. Although current market forces and regulations such as the European Union's Common Agricultural Policy, seem to foster agricultural intensification, a socially and ecologically optimal land-use strategy should seek to reconcile agricultural production with biodiversity conservation. Research on spatial land-use allocation lacks studies that consider both aspects simultaneously. Therefore, we developed a method that finds land-use strategies with a maximum contribution to social welfare, taking into account the landscape's biophysical potential. We applied a multiobjective optimization algorithm that identified landscape configurations that maximize agricultural production and biodiversity based on their contribution to social welfare. Social welfare was approximated by the profit contribution of agricultural production and society's willingness to pay for biodiversity. The algorithm simultaneously evaluated the biophysical outcomes of different land uses using the Soil and Water Assessment Tool (SWAT) and a biodiversity model. The method was applied to an agricultural landscape in central Germany. The results show that, in this area, overall social welfare can be increased compared to the status quo if both social benefits from biodiversity and economic profits from agricultural production are considered in land-use allocation. Further, the resulting optimal solutions can create win-win situations between the two, usually conflicting, objectives. The integration of preference information into the biophysical optimization allows reducing the usually large set of Pareto-optimal solutions and thus facilitates further stakeholder-based analyses. Our explorative study provides an example of how socioeconomic data and biophysical models can be combined to support decision making and the development of land-use policies.

International audience | Collembola have been proposed for several decades as a good model organisms to survey soil biodiversity; but most of the studies focused on taxonomic endpoints. The main objectives of this study are to compare the effects of the different land uses, including urban and industrial land uses, while using both collembolan functional and taxonomic biodiversity approaches. We collected data on 3,056 samples of Collembola communities across 758 sites in various land uses throughout France. The types of land use considered included all types of human activity from forestry to urban, industrial, traffic, mining and military areas, agricultural grassland, arable land, vineyards and urban vegetable gardens. In order to study functional and taxonomic biodiversity, we used community-weighted means, functional indices, species richness and density. When looking at collembolan functional diversity, urban and industrial soils appear clearly less diversified than when considering the taxonomic diversity. We suspect here a functional homogenization effect commonly reported in the literature for various organisms in urban ecosystems. Our study provides range of values for different taxonomic and functional indices of Collembola communities in a wide land use classification across France.

International audience | Land degradation impacts human well-being and biodiversity while increasing exposure to emerging infectious diseases. The primary indirect driver of land degradation is consumption, which increasingly involves agricultural products produced far away. Reversing these negative trends requires the decommoditization of land products through consumer-transparent "farm to table" information on land health combined with an efficient land use planning that is a greater optimization of land use and management decisions towards the achievement of multiple benefits.