Quantifying the effects of habitat fragmentation presents challenges due to the complexity of landscape-scale habitat configuration and its interaction with landscape and local processes. While patch-scale studies contribute valuable insights, extrapolating their findings to landscape scales is problematic due to the influence of landscape-scale processes. We used structural equation modelling to examine the direct and indirect effects of landscape-scale attributes around sampled forest patches including forest amount, edge density, number of patches, mean patch size, and mean interpatch distance, and patch- or plot-scale attributes including focal patch size, focal patch isolation, sample plot distance to forest edge, within-plot microhabitat heterogeneity, and plot soil pH, on species richness of woodland specialist plants in 16 sample plots within each of 97 British woodlands ('focal patches'). We find direct positive effects on woodland specialist richness of: (i) forest edge density in the landscape, suggesting positive effects of fragmentation per se, (ii) distance to forest edge of the sample plot, suggesting negative local edge effects, (iii) focal patch area, (iv) within-plot heterogeneity and (v) within-plot soil pH. We also find indirect positive effects of: (i) forest amount in the landscape through its indirect correlations to focal patch size and distance to forest edge, and (ii) number of forest patches in the landscape, through its correlation with edge density in the landscape. Synthesis. Our results suggest positive effects of fragmentation per se, that is fragmentation controlling for forest amount, on richness of specialist forest plants, despite their negative local edge response. This confirms that cross-scale extrapolation is not valid in habitat fragmentation research: negative patch-scale edge effects do not scale up to produce negative landscape-scale fragmentation effects. Cuantificar los efectos de la fragmentaci & oacute;n del h & aacute;bitat presenta dificultades debido a la complejidad de la configuraci & oacute;n del h & aacute;bitat a escala de paisaje y su interacci & oacute;n con los procesos locales y de paisaje. Aunque los estudios a escala de mancha aportan informaci & oacute;n valiosa, extrapolar sus resultados a escalas de paisaje es problem & aacute;tico por la influencia de los procesos que operan a esa escala. Utilizamos modelos de ecuaciones estructurales para examinar los efectos directos e indirectos de atributos a escala de paisaje en torno a las manchas forestales muestreadas-incluyendo la cantidad de bosque, la densidad de bordes, el n & uacute;mero de manchas, el tama & ntilde;o medio de mancha y la distancia media entre manchas-y de atributos a escala de mancha o parcela-incluyendo el tama & ntilde;o de la mancha focal, el aislamiento de la mancha focal, la distancia de la parcela de muestreo al borde del bosque, la heterogeneidad de microh & aacute;bitat dentro de la parcela y el pH del suelo-sobre la riqueza de especies de plantas especialistas de bosque en 16 parcelas de muestreo dentro de cada uno de 97 bosques brit & aacute;nicos (& laquo;manchas focales & raquo;). Encontramos efectos directos positivos sobre la riqueza de especialistas forestales de: (i) la densidad de bordes del bosque en el paisaje, lo que sugiere efectos positivos de la fragmentaci & oacute;n per se; (ii) la distancia al borde del bosque de la parcela de muestreo, lo que sugiere efectos de borde negativos a escala local; (iii) el & aacute;rea de la mancha focal; (iv) la heterogeneidad dentro de la parcela; y (v) el pH del suelo dentro de la parcela. Tambi & eacute;n encontramos efectos indirectos positivos de: (i) la cantidad de bosque en el paisaje, a trav & eacute;s de sus correlaciones indirectas con el tama & ntilde;o de la mancha focal y la distancia al borde del bosque, y (ii) el n & uacute;mero de manchas forestales en el paisaje, a trav & eacute;s de su correlaci & oacute;n con la densidad de bordes. S & iacute;ntesis. Nuestros resultados sugieren efectos positivos de la fragmentaci & oacute;n per se-es decir, la fragmentaci & oacute;n controlando la cantidad de bosque-sobre la riqueza de plantas especialistas de bosque, a pesar de su respuesta negativa al borde a escala local. Esto confirma que la extrapolaci & oacute;n entre escalas no es v & aacute;lida en la investigaci & oacute;n sobre fragmentaci & oacute;n del h & aacute;bitat: los efectos negativos de borde a escala de mancha no se traducen en efectos negativos de fragmentaci & oacute;n a escala de paisaje.

Abstract The challenge of energy production against a target of net‐zero emissions has led to the growth of policies promoting the cultivation and use of perennial biomass crops by governments in the United Kingdom and globally. Many of these crops are long‐lived and require low management inputs, raising questions about how the management of their field margins may influence biodiversity and whether interventions, including those funded by agri‐environment schemes, could enhance biodiversity alongside the crop. In intensive, temperate agricultural systems, crop margins are widely recognised as important for supporting farmland biodiversity; however, little research has focused on how the margins of low‐intensity perennial biomass crops function in this role. These margins can differ from conventional arable margins in structure, shading and management intensity, meaning that their biodiversity potential, and the management practices most likely to enhance it, remain poorly understood. Our study focuses specifically on the management of margins surrounding short‐rotation coppice (SRC) willow and miscanthus, aiming to identify approaches most likely to benefit plant biodiversity. We combined fine‐resolution soil and plant niche models with field surveys to evaluate how different management practices may affect habitat suitability for grassland species. High residual soil fertility emerged as a major constraint on establishing forb‐rich grassland assemblages, including those targeted by conservation seed mixes. Model simulations indicate that reducing fertility through repeated cutting and removal of plant material can improve suitability, though gains are gradual and strongly site‐dependent. Margin width also played a critical role, with narrow, shaded margins showing reduced suitability for light‐demanding species, consistent with shade‐driven edge‐to‐area effects. Field surveys revealed very low frequencies of target forb species, confirming that assisted introduction is required where species‐rich outcomes are desired. Synthesis and applications . Together, these results highlight the need for margin‐specific management guidance for perennial biomass crops and demonstrate how niche‐based modelling can inform the design of effective agri‐environment options.

Mobile applications with automated species identification can assist citizen scientists in undertaking plant and habitat surveys. Whilst a high level of accuracy for these applications has been reported, very little testing has been done with citizen scientists in the field. If such applications are going to be used to support biodiversity research and conservation management, they need to be sufficiently accurate and functional for their intended use. We evaluated the accuracy of the e-Surveyor mobile application, which includes automated identification for plant species and habitat prediction. We compared species lists and derived habitat associations collected by citizen scientists using the application in the field, with data recorded by expert botanists within the same survey plots. We also assessed the user experience via a questionnaire. Thirty-seven citizen scientists attended the e-Surveyor workshops and completed a questionnaire, with 51 individual plant surveys submitted across the three habitat types: calcareous grassland, neutral grassland and improved grassland. On average, experts recorded more plant species per plot compared with citizen scientists. Of the species recorded by citizen scientists on e-Surveyor that were known to be present, 71% were correctly identified to species level, though typically only 45% of all observable species in the plot according to the expert botanists were captured correctly by the citizen scientists. Eighty per cent of surveys identified the correct first broad habitat and 25% identified the correct first phytosociological community suggested by the application. Citizen scientists provided valuable input through the questionnaire, including improvements to e-Surveyor and future use cases. Most citizen scientists were able to accurately identify almost half of the observable plant species present and determine the correct broad habitat using e-Surveyor, regardless of their botanical skill level. This suggests that the application is a useful tool for supporting biological recording, whilst improving confidence, knowledge and engagement with nature.

High rates of soil organic carbon (SOC) loss from cropland soils are well known, contributing to climate change and compromising soil and ecosystem health. Stabilising and reversing the loss of organic matter from cropland soils is a challenge for all nations to meet the United Nations Sustainable Development Goals. Sustainable land management (SLM) has been promoted as a mechanism of achieving this, but to date, there is no evidence of positive impacts at scale. Here we show the first signs of the reversal of soil carbon loss in cultivated topsoils in Great Britain, following a period of reported SLM uptake, using 40+ years of national soil monitoring from the UKCEH Countryside Survey. Following a prolonged historic decline at rates of -0.16 t ha-1 year-1, there was a significant increase in cropland topsoil SOC stocks (0-15 cm) from 2007 to 2019-22 with an accrual rate of 0.17 t ha-1 year-1, approximately 0.74 MtC year-1 nationally. We discuss reported management shifts in Great Britain in the corresponding period and identify a reduction in conventional tillage and reduced straw removal as potential drivers, but highlight additional evidence gaps worthy of consideration. This increase in topsoil SOC may represent net carbon sequestration or carbon redistribution (geographic or vertical) but nevertheless demonstrates that topsoil properties can be restored at scale and offers hope that a concerted effort by land managers can halt, and potentially reverse, SOC loss from cropland soils.

Tree diseases are increasingly affecting woodland ecosystems across the world. However, the impact of these diseases upon the soil, and in particular soil carbon, is still poorly understood. Here we present the results of a field survey of ~100 woodlands across Great Britain measured in 1971, 2001 and 2022 and evaluate the fifty-year trend in topsoil (0-15 cm) carbon based upon measurements of soil organic matter (SOM) and the impact of Hymenoscyphus fraxineus (ash dieback). To better represent the full SOM distribution, including the extremely high SOM measurements, we adopt a Beta mixture modelling approach within a Bayesian framework. Across all woodlands, comprising ~1,500 plots per survey, average SOM remained constant across the fifty-year time series. However, the 311 plots with ash dieback had lower SOM in the most recent survey compared to the 328 plots with ash trees present but no dieback recorded, due to a slight decline in SOM under ash dieback. This resulted in plots with ash dieback having a modelled mean SOM of 12.2% compared to 13.4% in plots without ash dieback, a difference of 1.23 percentage points (95% CI 0.25-2.21). Ash dieback was more likely to be recorded in plots that had higher soil pH pre-ash dieback invasion, but the decline in SOM under ash dieback was not explained by changes in soil pH or changes in the ground flora composition. Converting our results to soil C and extrapolating for broadleaved woodland across the entirety of Great Britain, the total amount of topsoil carbon lost to date due to ash dieback could be 6 MtCO2 (± 4 s.d.). Our results show the importance of understanding the impacts of tree disease when considering current and future woodland carbon dynamics.

The GBNVPD (GIVD-code EU-GB-007) is the new centralised repository for the collection and storage of standardised vegetation plot data in Great Britain and the Crown Dependencies. The initial version of the GBNVPD (v1.0) described in this long database report comprises data from 63 individual sources and contains 277,070 samples from 200,733 plots, with a total of 4,463,300 occurrences of 4,086 accepted taxa (3,464 accepted species), surveyed between 1949 and 2024. Of the 63 constituent datasets 52 are newly submitted to the EVA and 9 to ReSurveyEurope. The database is available under a discretionary mixed-access regime and will be maintained and updated continuously in response to further digitisation of historic paper records, collection of pre-existing digitised survey data, and addition of future survey data. Abbreviations: EVA = European Vegetation Archive; GB = Great Britain; GBNVPD = National Vegetation Plot Database for Great Britain and the Crown Dependencies; NVC = National Vegetation Classification; UKCEH = United Kingdom Centre for Ecology and Hydrology; UKSI = United Kingdom Species Inventory.

Globally pervasive increases in atmospheric CO2 and nitrogen (N) deposition could have substantial effects on plant communities, either directly or mediated by their interactions with soil nutrient limitation. While the direct consequences of N enrichment on plant communities are well documented, potential interactions with rising CO2 and globally widespread phosphorus (P) limitation remain poorly understood. We investigated the consequences of simultaneous elevated CO2 (eCO2 ) and N and P additions on grassland biodiversity, community and functional composition in P-limited grasslands. We exposed soil-turf monoliths from limestone and acidic grasslands that have received >25 years of N additions (3.5 and 14 g m-2  year-1 ) and 11 (limestone) or 25 (acidic) years of P additions (3.5 g m-2  year-1 ) to eCO2 (600 ppm) for 3 years. Across both grasslands, eCO2 , N and P additions significantly changed community composition. Limestone communities were more responsive to eCO2 and saw significant functional shifts resulting from eCO2 -nutrient interactions. Here, legume cover tripled in response to combined eCO2 and P additions, and combined eCO2 and N treatments shifted functional dominance from grasses to sedges. We suggest that eCO2 may disproportionately benefit P acquisition by sedges by subsidising the carbon cost of locally intense root exudation at the expense of co-occurring grasses. In contrast, the functional composition of the acidic grassland was insensitive to eCO2 and its interactions with nutrient additions. Greater diversity of P-acquisition strategies in the limestone grassland, combined with a more functionally even and diverse community, may contribute to the stronger responses compared to the acidic grassland. Our work suggests we may see large changes in the composition and biodiversity of P-limited grasslands in response to eCO2 and its interactions with nutrient loading, particularly where these contain a high diversity of P-acquisition strategies or developmentally young soils with sufficient bioavailable mineral P.

Plant communities are being exposed to changing environmental conditions all around the globe, leading to alterations in plant diversity, community composition, and ecosystem functioning. For herbaceous understorey communities in temperate forests, responses to global change are postulated to be complex, due to the presence of a tree layer that modulates understorey responses to external pressures such as climate change and changes in atmospheric nitrogen deposition rates. Multiple investigative approaches have been put forward as tools to detect, quantify and predict understorey responses to these global-change drivers, including, among others, distributed resurvey studies and manipulative experiments. These investigative approaches are generally designed and reported upon in isolation, while integration across investigative approaches is rarely considered. In this study, we integrate three investigative approaches (two complementary resurvey approaches and one experimental approach) to investigate how climate warming and changes in nitrogen deposition affect the functional composition of the understorey and how functional responses in the understorey are modulated by canopy disturbance, that is, changes in overstorey canopy openness over time. Our resurvey data reveal that most changes in understorey functional characteristics represent responses to changes in canopy openness with shifts in macroclimate temperature and aerial nitrogen deposition playing secondary roles. Contrary to expectations, we found little evidence that these drivers interact. In addition, experimental findings deviated from the observational findings, suggesting that the forces driving understorey change at the regional scale differ from those driving change at the forest floor (i.e., the experimental treatments). Our study demonstrates that different approaches need to be integrated to acquire a full picture of how understorey communities respond to global change.

There is strong evidence that landscape-scale factors such as habitat diversity, composition and configuration are important drivers of declines in pollinators and pollination services. However, context and species-specific responses make it challenging to draw general conclusions about the most important components of landscapes that support diverse and abundant pollinator communities. In this study, we took a functional-traits approach to community assembly and tested the hypothesis that landscape properties act most strongly on pollinators indirectly, through their influence on flowering plant communities. Using plant and pollinator data from 96 landscapes in Britain, we tested the associations between plant and pollinator communities and local environmental factors, such as habitat cover and configuration, using path analysis based on Mantel and partial Mantel statistics. When all pollinators were considered, we found that the environmental factors had stronger links to the composition of flowering plant communities than to the composition of pollinator communities. Further, the flowering plant community was strongly linked to the pollinator community suggesting a mediating role between land use and pollinators. When separating the pollinator community into taxonomic groups, we found the same result for hoverflies, but wild bees were linked to both environmental factors and flowering plants. We further explored these links with structural equation models using the response-effect trait framework as a guiding principle. We found strong evidence that land-use composition and configuration influence the trait distribution and functional diversity of the pollinator community via plant community composition. These findings suggest that the indirect effect of land use on pollinators via flowering plants should be considered in informing the design of pollinator friendly landscapes and in future research of the effects of land use and management on wild pollinators.Read the free Plain Language Summary for this article on the Journal blog. Read the free Plain Language Summary for this article on the Journal blog.image

Soil organic carbon (SOC) is a soil health indicator and understanding dynamics changing SOC stocks will help achieving net zero goals. Here we present four datasets featuring 11,750 data points covering co-located aboveground and below-ground metrics for exploring ecosystem SOC dynamics. Five sites across England with an established land use contrast, grassland and woodland next to each other, were rigorously sampled for aboveground (n = 109), surface (n = 33 soil water release curves), topsoil, and subsoil metrics. Commonly measured soil metrics were analysed in five soil increments for 0–1 metre (n = 4550). Less commonly measured soil metrics which were assumed to change across the soil profile were measured on a subset of samples only (n = 3762). Additionally, we developed a simple method for soil organic matter fractionation using density fractionation which is part of the less common metrics. Finally, soil metrics which may impact SOC dynamics, but with less confidence as to their importance across the soil profile were only measured on topsoil (~5–15 cm = mineral soil) and subsoil (below 50 cm) samples (n = 2567).

The European Union has a long-term objective to achieve healthy soils by 2050. The European Commission has proposed a Directive of the European Parliament and of the Council on Soil Monitoring and Resilience (Soil Monitoring Law, SML), the first stage of which is to focus on setting up a soil monitoring framework and assessing soils throughout the EU. Situated in NW Europe, the UK has substantial experience in soil monitoring over the last half century which may usefully contribute to this wider EU effort. A set of overarching principles have and continue to guide design of national soil monitoring and may prove helpful as other European countries embark on similar monitoring programmes. Therefore, we present the principles of design from five decades of national soil monitoring. The monitoring discussed is based on a stratified-random design, has matured in support of policy questions, and operates over space and time scales relevant to the SML. The UK Centre for Ecology & Hydrology (UKCEH) Countryside Surveys (CS) of Great Britain and Northern Ireland, Welsh Government, Environment and Rural Affairs Monitoring and Modelling Programme (ERAMMP) and the England Ecosystem Survey (EES) monitoring programme are national programmes currently operating in the UK. Some important lessons learnt include: adopting a question-based approach; having a clear robust statistical design for the purpose; selecting indicators that address policy and underlying scientific questions; and selecting indicators that can detect change and use robust and well-tested methodologies across a wide range of soil and land use types, remaining valid over long time scales, supporting thinking long-term. Technical lessons learned include the proven cost effectiveness of a stratified-random design including replication, while adopting a common stratification layer of stable environmental attributes aids comparability between monitoring programmes. Common protocols are vital for future intercomparisons, but a full ecosystem approach that includes co-located soil and vegetation samples for interpreting a co-evolving system has proved hugely advantageous. UK monitoring programmes offer a range of experience that may prove valuable to future soil monitoring design to address the major societal challenges of our time, such as maintaining food production and addressing climate change and biodiversity loss.

To predict how biodiversity will respond to global change, it is crucial to understand the relative roles of abiotic drivers and biotic interactions in driving associations between the biodiversity of disparate taxa. It is particularly challenging to understand diversity-diversity links across domains and habitats, because data are rarely available for multiple above- and below-ground taxa across multiple sites. Here, we analyse data from a unique biodiversity data set gathered across a variety of oceanic temperate terrestrial habitats in Wales, comprising 300 sites with co-located soil microbial, plant, bird and pollinator surveys along with climate and soil physicochemical information. Soil groups are analysed using metabarcoding of the 16S, ITS1 and 18S DNA regions, allowing in-depth characterisation of microbial and soil animal biodiversity. We explore biodiversity relationships along three aspects of community composition: First, we assess correlation between the alpha diversity of different groups. Second, we assess whether biotic turnover between sites is correlated across different groups. Finally, we investigate the co-occurrence of individual taxa across sites. In each analysis, we assess the contribution of linear or nonlinear environmental effects. We find that a positive correlation between alpha diversity of plants, soil bacteria, soil fungi, soil heterotrophic protists, bees and butterflies is in fact driven by complex nonlinear responses to abiotic drivers. In contrast, environmental variation did not account for positive associations between the diversity of plants and both birds and AM fungi, suggesting a role for biotic interactions. Both the diversity and taxon-level associations between the differing soil groups remained even after accounting for nonlinear environmental gradients. Above-ground, spatial factors played larger roles in driving biotic communities, while linear environmental gradients were sufficient to explain many group- and taxon-level relationships. Synthesis. Our results show how nonlinear responses to environmental gradients drive many of the relationships between plant biodiversity and the biodiversity of above- and below-ground biological communities. Our work shows how different aspects of biodiversity might respond nonlinearly to changing environments and identifies cases where management-induced changes in one community could either influence other taxa or lead to loss of apparent biological associations. Our work shows how nonlinear responses to environmental gradients drive many of the relationships between plant biodiversity and the biodiversity of above- and below-ground biological communities. This demonstrates how different aspects of biodiversity might respond nonlinearly to changing environments and identifies cases where management-induced changes in one community could either influence other taxa or lead to loss of apparent biological associations.image

Abstract Agri‐environment schemes (AES) incentivise land‐management practices aimed at mitigating environmental impacts. However, their effectiveness depends on the duration and type of management. We modelled the potential for grassland AES options in Wales (UK) to achieve positive changes in plant diversity via change in soil conditions. We modelled the response of plants and soils to the predicted effects of AES options over a 13‐year time interval. We applied scenarios of change in soil conditions in three managed grassland types, using high‐resolution baseline soil and vegetation data collected in grasslands across Wales, UK. We also applied scenarios of climate change to determine the extent to which this might modify the impact of AES intervention on plant species compositional turnover. Empirical models of soil response to extensification were constructed from published experimental data and used to drive change in soil inputs to a small ensemble of ecological niche models for British plants. These models were applied to the local pool of species in each baseline (2 × 2 m) quadrat plus a wider 10 × 10 km pool from which we draw species absent at baseline but predicted to find conditions suitable as a result of AES intervention and climate change, thus estimating dark diversity at each location. Outputs were summarised by grouping species by the ecosystem functions and services they support and by matching projected species composition to the UK National Vegetation Classification. Scenario modelling indicated that at least 10 years of management under grassland AES options were needed to achieve conditions suitable for desirable plant assemblages more typical of lower fertility habitats. Synthesis and applications: We predict that management effects will have a more marked effect on vegetation and soil than predicted climate variation up to 2029. Realising modelled changes in habitat suitability as species compositional turnover and community assembly is likely to require additional measures to assist plant dispersal and establishment.

Forest creation has the potential to reduce biodiversity loss and mitigate climate change but, tree disease emergence may counteract this. Further, given decadal timescales required for forest establishment, climate change is increasingly likely to act as a filter on plant community assembly. In the temperate lowlands succession takes 30 to 50 years for non-forest land to establish woodland plant assemblages, while the timescales required for new forest to sequester carbon suggest unassisted succession will be too slow for net zero 2050 targets. However, if plantations can establish faster than succession it would be beneficial to recommend planting native species as soon as possible. We explore scenarios of broadleaved woodland development across Wales, UK, as a case study area. We use a suite of empirical species niche models for British plants to estimate the potential species composition of forests with, and without, projected climate change. Additionally, we examine how tree canopy composition alters if Fraxinus excelsior is widely impacted by ash-dieback ( Hymenoscyphus fraxineus ). The results suggest soil total carbon and nitrogen could achieve baseline broadleaved forest values in less than 30 years. However only timber and woody flora species groups showed diversity surpassing baseline broadleaved forest diversity, with nectar plants and ancient woodland indicator species failing to reach baseline equivalents within 30 years; although complete congruence is unlikely given baseline forests could be hundreds of years old. Where Fraxinus excelsior was removed from the species pool we predicted that a scrub phase will persist or, if present, Acer pseudoplatanus will become the canopy dominant. The heavier shade cast this species is likely to result in differences in species composition of the understory and ground flora diversity is likely to decrease. Reliance on unassisted succession will also depend critically on (a) dispersal from local source populations and (b) on establishment filters that could be severe in landscapes with high management intensity history. These findings indicate that leaving the UK’s fragmented habitats to relying on already degraded successional processes could lead to poor afforestation outcomes. Highlights Afforestation can mitigate global change but tree disease makes outcomes uncertain Afforestation methods establishment timescales and time for benefits to occur We model afforestation and predict how soils and plants change with climate Ash loss from die-back is replaced by low low-canopy woodland / scrub over 30 years Afforestation achieves baseline forest values for some variables within 30 years

Extreme weather events are increasing in frequency and magnitude with profound effects on ecosystem functioning. Further, there is now a greater likelihood that multiple extreme events are occurring within a single year. Here we investigated the effect of a single drought, flood or compound (flood + drought) extreme event on temperate grassland ecosystem processes in a field experiment. To assess system resistance and resilience, we studied changes in a wide range of above- and below-ground indicators (plant diversity and productivity, greenhouse gas emissions, soil chemical, physical and biological metrics) during the 8 week stress events and then for 2 years post-stress. We hypothesized that agricultural grasslands would have different degrees of resistance and resilience to flood and drought stress. We also investigated two alternative hypotheses that the combined flood + drought treatment would either, (A) promote ecosystem resilience through more rapid recovery of soil moisture conditions or (B) exacerbate the impact of the single flood or drought event. Our results showed that flooding had a much greater effect than drought on ecosystem processes and that the grassland was more resistant and resilient to drought than to flood. The immediate impact of flooding on all indicators was negative, especially for those related to production, and climate and water regulation. Flooding stress caused pronounced and persistent shifts in soil microbial and plant communities with large implications for nutrient cycling and long-term ecosystem function. The compound flood + drought treatment failed to show a more severe impact than the single extreme events. Rather, there was an indication of quicker recovery of soil and microbial parameters suggesting greater resilience in line with hypothesis (A). This study clearly reveals that contrasting extreme weather events differentially affect grassland ecosystem function but that concurrent events of a contrasting nature may promote ecosystem resilience to future stress.

A common practice used to restore and maintain biodiversity in grasslands is to stop or decrease the use of fertilizers as they are a major cause of biodiversity loss. This practice is problematic for farmers who need fertilizers to increase forage and meet the nutritional needs of livestock. Evidence is needed that helps identify optimal fertilizer regimes that could benefit biodiversity and livestock production simultaneously over the long-term. Here, we evaluated the impact of different fertilizer regimes on indicators related to both biodiversity (plant, pollinator, leaf miners and parasitoid Shannon-Weiner diversity, bumblebee abundance, nectar productivity and forb species richness), and forage production (ash, crude protein, ruminant metabolizable energy and dry matter). To this end, we used data from a grassland restoration experiment managed under four nutrient inputs schemes for 27 years: farmyard manure (FYM; 72 kg N ha-1 yr-1), artificial nitrogen-phosphorus and potassium (NPK; 25 kg N ha-1 yr-1), FYM + NPK (97 kg N ha-1 yr-1) and no-fertilizer. Results showed strong trade-offs between biodiversity and forage production under all treatments even in applications lower than the critical load in the EU. Overall, farmyard manure was the fertilizer that optimized production and biodiversity while 97 kg N ha-1 yr-1 of fertilizer addition (FYM+NPK) had the most negative impact on biodiversity. Finally, forage from places where no fertilizer has been added for 27 years did not meet the nutritional requirements of cattle, but it did for sheep. Rethinking typical approaches of nutrient addition could lead to land management solutions suitable for biological conservation and agriculture.

Relationships between area, heterogeneity and species richness are fundamental concepts in ecology yet questions remain about how area and heterogeneity tradeoff (AHTO) to constrain biodiversity. Although there is growing evidence for unimodal heterogeneity diversity relationships (HDR's) and an AHTO, tests of the concept and consequences for species richness across a landscape‐scale gradient of human‐modified ecosystems are rare. Using data from a national (Wales) field survey we analysed relationships between environmental heterogeneity and plant species richness (α and γ). We used ordination to produce a composite metric of heterogeneity and compared this to commonly used metrics. We used niche hypervolumes to categorise the breadth of plant species' ecological preferences and analysed relationships between species richness, niche width and heterogeneity. The HDR was unimodal with α diversity at the smallest scale and positive with α and γ diversity (non‐linear) at the 1 km scale although in low intensity landscapes the HDR with γ diversity was unimodal. There was a unimodal relationship between habitat diversity and γ diversity. Land use intensity was unimodally related to diversity. There were significant interactions between niche width and heterogeneity. Richness of broad niche species increased with heterogeneity with flattening of the curve at higher levels. Narrow niche species were rare and mostly unresponsive. The expected decline in narrow niche species with increasing heterogeneity was not found although they did decline with land‐use intensity. Using a unique dataset, an analysis of a large‐scale mosaic of ecosystems found that the shape of the HDR varies with land use intensity, the heterogeneity metric, spatial scale, diversity type and niche width. Although heterogeneity can increase species richness, there may be tradeoffs at higher heterogeneity. A fundamental constraint on realising the benefit of heterogeneity is the low availability of narrower niche species in local species pools in modified landscapes.

The utility of integrated models for informing policy has been criticised due to limited stakeholder engagement, model opaqueness, inadequate transparency in assumptions, lack of model flexibility and lack of communication of uncertainty that, together, lead to a lack of trust in model outputs. We address these criticisms by presenting the ERAMMP Integrated Modelling Platform (IMP), developed to support the design of new “business-critical” policies focused on agriculture, land-use and natural resource management. We demonstrate how the long-term (>5 years), iterative, two-way and continuously evolving participatory process led to the co-creation of the IMP with government, building trust and understanding in a complex integrated model. This is supported by a customisable modelling framework that is sufficiently flexible to adapt to changing policy needs in near real-time. We discuss how these attributes have facilitated cultural change within the Welsh Government where the IMP is being actively used to explore, test and iterate policy ideas prior to final policy design and implementation.

Sulphur deposition through rainfall has led to species loss and ecosystem degradation globally, and across Europe huge reductions in sulphur emissions since the 1970s were expected to promote the recovery of acidified ecosystem. However, the rate and ecological impact of recovery from acidification in terrestrial ecosystems is still unclear as is the influence of management and climate, as to date there has been no long-term spatially extensive evaluation of these changes. Here we present data from thousands of sites across Great Britain surveyed repeatedly from 1978-2019 and assess change in soil pH and plant acidity preference (Ellenberg R) in response to atmospheric deposition of sulphur and nitrogen. We analyse change in grasslands managed for pasture, referred to as high-intensity habitats, and compare to semi-natural habitats comprising rough grassland, broadleaved woodland, bog and heathland, referred to as low-intensity habitats. Soil pH increased from 1978 to 2007 but then decreased between 2007 and 2019, resulting in a net increase of ~0.2 pH units in low-intensity habitats but no change in high-intensity habitats. The community average Ellenberg R increased in semi-natural habitats by ~0.2 units but remained stable in intensive grasslands. In semi-natural habitats, but not intensive grasslands, these changes in plant community composition were associated with the soil pH changes which were in turn linked to decreasing sulphur deposition and differences in rainfall. Nitrogen deposition, which was relatively stable over the survey period, showed no additional effect upon soil acidity once sulphur deposition was accounted for. Synthesis: Our results provide conclusive evidence that reductions in acid emissions are stimulating the gradual recovery of chronically acidified terrestrial ecosystems at a whole-country scale, while also suggesting this recovery is being compromised by changing climate and land management.

Soils are a key natural capital asset. Soil health, defined as the capacity of a soil to function as a living system, is a vital component of wider ecosystem processes and functioning, including the flow of multiple ecosystem services. Land use change is an important factor influencing declines in soil health globally. To meet demand for low carbon energy, ground-mounted solar parks (SPs) have expanded rapidly in recent decades, incurring significant land use change, with predictions that UK solar capacity could quadruple by 2050. There is potential for both positive and negative impacts of SPs on soil health - SPs present a relatively unique land use change, in that large areas of land remain physically undisturbed but are shaded by panels. This shading can alter microclimate metrics under panels, including air and soil temperature, soil moisture, photosynthetically active radiation and humidity, which may impact indicators of soil health. Further, the majority of SPs in the UK are developed on former agricultural land, often intensively managed. Arable land use is one of the most detrimental to overall soil health, whilst there is significant evidence supporting the benefits of taking agricultural land out of cultivation, including increased soil carbon, reduced erosion, compaction, and pollution. Considering the land use requirements and microclimatic variation within SPs, it is critical that their impacts on soil health are understood, yet research on solar park-soil impacts remains sparse.We investigated the impact of location within SPs (under solar panels and in gap areas) and the influence of prior land use (arable and grassland) on physical, chemical, and biological indicators of soil health, to address this knowledge gap and provide one of the first quantifications on the impacts of SP development on soil health. Preliminary results suggest no difference in indicators with SP prior land use, however bulk density and inorganic phosphorus were significantly lower in gap areas compared to under panels, whilst organic matter and microbial biomass carbon were higher in gap areas. These results suggest that soil health may be degraded under the shade of solar panels.However, on-site management decisions such as livestock grazing, wildflower planting and mowing regimes likely influence soil health indicator values and vary across SPs. Further, the SPs studied have been operational since 2014, a relatively short time in terms of soil health. As such, further research is required across spatial and temporal scales, considering the impact of SP management actions to accurately infer SP impacts on soil health.