ABSTRACT Bracken ( Pteridium aquilinum ) is of major concern to land managers due to its ability to invade grassland and heathland systems, but it is believed to indicate where woodland once was or where conditions may be favourable for woodland in the future. The effects of bracken on the soil system are also not well understood despite the key role of soils in carbon and nutrient cycling and as one of the most biodiverse habitats on the planet. Whilst soil mesofauna are amongst the most abundant animals and present at multiple trophic levels in the soil food web, the importance of their diversity remains underappreciated and overlooked in policy and land management. Due to their role in litter decomposition, mesofauna should be explored in light of the conspicuous shift in litter form and quantity when bracken is present. In this study, soil mites, springtails, nematodes and soil properties in grassland and heathland were compared to those in woodland in the presence and absence of bracken to ascertain whether these communities could provide useful detail for potential woodland restoration. Under bracken soils, total and water‐extractable organic carbon, water‐extractable nitrogen, C:N ratios, Zn 2+ concentrations and mesofauna abundances were lower. Reductions in microinvertebrate α‐diversity under bracken were specific to heathland only, whilst β‐diversity in grassland and heathland was enhanced under bracken by increased morphotype turnover. These results indicate that soil nutrients and communities under bracken do not represent a shift towards those found in woodland soils and are more strongly driven by ecosystem type than plant species composition or the presence of bracken. Future work should investigate whether bracken is causing the observed differences in soil nutrients and community structure, focusing on possible mechanistic drivers such as changes in bacterial‐fungal ratios and microbial activity.

Soil pH indicates the level of acidity or alkalinity in the soil environment, influencing various biogeochemical and physical processes. Additionally, soil pH levels are crucial in determining the bioavailability of elements such as iron, aluminium, and heavy metals which can be harmful. As such, pH is an important soil health and degradation indicator. Although there is a well-established understanding of soil pH at localized levels, the spatial and temporal variations, as well as significant thresholds at national and continental scales, are not sufficiently documented. Here we analyse the European topsoil pH data (LUCAS) in combination with other soil properties from the LUCAS survey, to identify thresholds and spatial patterns of soil pH across Europe in relation to soil health and degradation. At the European scale we found: 1) the water balance, calculated as mean annual precipitation minus potential evapotranspiration (MAP-PET), provides essential context to interpret soil pH; 2) the shift from organic carbon-rich soils to those dominated by inorganic carbon is observed at a pH of about 7.2, however, soil moisture levels may be more critical than pH for the accumulation of soil organic carbon; 3) we identified three distinct clusters within the multivariate regression tree: acidophiles (below pH 5.2), neutrophiles (pH 5.2-6.9) and alkaliphiles (above pH 6.9), while optimum microbial diversity occurred between pH 6 and 7. Earthworm abundance, as reported by the sWorm database, is more nuanced and dependent on land use; 4) risk of degradation by heavy metals cannot be captured by a single pH threshold. Finally, we identify soil pH thresholds that can aid policymakers in identifying regions that may require protection or intervention.

Soil Quality or Soil Health are terms adopted by the scientific community as metaphors for the effects of differing land management practices on the properties and functions of soil. Because they are metaphors, consistent quantitative definitions are lacking. We present here an approach based on expert elicitation in the field of soil function and management that offers a universal way of putting numbers to the metaphor. Like humans, soils differ and so do the ways in which they are understood to become unhealthy. Long-term experiments such as the Broadbalk Wheat experiment at Rothamsted provide unparalled sources of data with which to investigate the state and changes of soil quality and health that have developed from known management over timescales of one hundred years or more. Similarly, large-scale datasets such as the National Soils Inventory and Countryside Survey provide rich resources to explore the geographical variability of soil quality and health in different places against a background of different observed management practices. We structure experts’ views of the extent to which soil delivers the functions expected of it within Bayesian Belief Networks anchored by measurable properties of soil. With these networks, we infer the likely state of soil (i) on Broadbalk, (ii) at locations throughout England & Wales as well as inferring (iii) the most straightforward ways of improving soil quality and health at the locations in (ii). Our methodology has general applicability and could be deployed elsewhere or in other disciplines.

The summer drought in the United Kingdom (UK) in 2022 produced significant speculation concerning how its termination may impact and interact with the soil resource. Whilst knowledge regarding soils and droughts exists in the scientific literature, a coherent understanding of the wider range of impacts on soil properties and functions has not been compiled for temperate soils. Here, we draw together knowledge from studies in the UK and other temperate countries to understand how soils respond to drought, and importantly what and where our knowledge gaps are. First, we define the different types of droughts and their frequency in the UK and provide a brief overview on the likely societal impacts that droughts place on the soil and related ecosystems. Our focus is on ‘agricultural and ecosystem drought’, as this is when soils experience dry periods affecting crops and ecosystem function, followed by rewetting. The behaviour of moisture in soils and the key processes that contribute to its storage and transport are examined. The principal changes in the physical, chemical, and biological properties of soils resulting from drought, and rewetting (i.e., drought termination) are discussed and their extensive interactions are demonstrated. Processes that are involved in the rewetting of soils are explored for soil and catchment-scale soil responses. Lastly, soils’ recovery after drought is considered, knowledge gaps are identified, and areas to improve understanding are highlighted.

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.

Greenhouse gas stabilisation in the atmosphere is one of the most pressing challenges of this century. Sequestering carbon in the soil by changing land use and management is increasingly proposed as part of climate mitigation strategies, but our understanding of this is limited in quantitative terms. Here we collate a substantial national and regional data set (15 790 soil cores) and analyse it in an advanced statistical modelling framework. This produced new estimates of the effects of land use on soil carbon stock (Sc) in the UK, different in magnitude and ranking order from the previous best estimates. Soil carbon stocks were highest in woodlands, followed by rough grazing, semi-natural grasslands, and improved grasslands, and they were lowest in croplands. Estimates were smaller than the previous estimates, partly because of new data, but mainly because the effect is more reliably characterised using a logarithmic transformation of the data. With the very large data set analysed here, the uncertainty in the differences among land uses was small enough to identify consistent mean effects. However, the variability in these effects was large, and this variability was similar across all surveys. This has important implications for agri-environment schemes seeking to sequester carbon in the soil by altering land use, because the effect of a given intervention is very hard to verify. We examined the validity of the "space-for-time" substitution, and, although the results were not unequivocal, we estimated that the effects are likely to be overestimated by 5 %-33 %, depending upon land use.

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

Soil Quality or Soil Health are terms adopted by the scientific community as metaphors for the effects of differing land management practices on the properties and functions of soil. We present here an approach based on expert elicitation in the field of soil function and management that offers a universal way of putting numbers to the metaphor. Like humans, soils differ and so do the ways in which they are understood to become unhealthy.Long-term experiments such as the Broadbalk Wheat experiment at Rothamsted provide unparalled sources of data with which to investigate the state and changes of soil quality and health that have developed from known management over timescales of one hundred years or more. Similarly, large-scale datasets such as the National Soils Inventory and Countryside Survey provide rich resources to explore the geographical variability of soil quality and health in different places against a background of different observed management practices.We structure experts’ views of the extent to which soil delivers the functions expected of it within Bayesian Belief Networks anchored by measurable properties of soil. With these networks, we deduce the value of additional data to the precision of estimates of soil quality and health and infer the likely state of soil (i) on Broadbalk, (ii) at locations throughout England & Wales and (iii) the most straightforward ways of improving soil quality and health at the locations in (ii). Our methodology has general applicability and could be deployed elsewhere or in other disciplines.

Abstract Natural capital and ecosystem services have emerged as fundamental concepts of ecosystem management strategies in the past two decades, particularly within major international land assessment frameworks, including the UN's Millennium Ecosystem Assessment and the Intergovernmental Science‐Policy Platform on Biodiversity and Ecosystem Services' Global Assessment Report. Despite the recent development of several analytical methods and models to quantify changes in natural capital and ecosystem services resulting from land use change, incorporating them into the land planning process can be challenging from a practical point of view without guidance on standard methods. In an attempt to decarbonize energy supply systems to meet internationally agreed targets on climate change, solar energy production, in the form of ground‐mounted solar parks, is emerging as one of the dominant forms of temporary land use for renewable energies globally. We propose 19 directly measurable indicators associated with 16 ecosystem services within three major stocks of natural capital (biodiversity, soil and water) that are most likely to be impacted by the development of solar parks. Indicators are supported by well‐established methods that have been widely used in pure and applied land use research within terrestrial ecosystems. Moreover, they can be implemented flexibly according to interest or land management objectives. Whilst not intended as a precise recipe for how to assess the effects of solar park development on hosting ecosystems, the protocol will guide the solar energy industry and all actors involved, be they researchers, practitioners, ecological consultancies or statutory bodies, to implement a standardized approach to evaluate temporal and spatial changes in natural capital and ecosystem services resulting from solar park development and operation, with the ultimate aim of generating comparable and reproducible data on ecosystem impact assessment across the solar energy sector.

Efforts to improve soil health require that target values of key soil properties are established. No agreed targets exist but providing population data as benchmarks is a useful step to standardise soil health comparison between landscapes. We exploited nationally representative topsoil (0-15 cm) measurements to derive soil health benchmarks for managed and semi-natural environments across Great Britain. In total, 4587 soil organic matter (SOM), 3860 pH, 2908 bulk density (BD), and 465 earthworm abundance (EA) datapoints were used. As soil properties are sensitive to site-specific characteristics, data were stratified by habitat, soil type, and mean annual precipitation, with benchmarks defined as the middle 80 % of values in each distribution - yielding 135 benchmarks. BD and pH decreased with land management intensity (agriculture > semi-natural grasslands > woodlands > heathlands > wetlands), and vice versa for SOM and EA. Normalising benchmark ranges by medians revealed soil health indicator benchmark widths increased in the order: pH < BD < SOM < EA, while width increased with decreasing land management intensity. Arable and horticulture and improved grassland exhibited narrow benchmarks for SOM, pH and BD, yet the widest EA benchmark, suggesting additional drivers impact EA patterns. Upland wetlands had the widest BD benchmarks, important when determining carbon stocks. East Anglia currently possesses the largest proportions of atypical soils, including below typical SOM (19.2 %), above typical BD (17.4 %) and pH (39.1 %), and the smallest proportions of above typical SOM (2.4 %), and below typical BD (5.8 %) and pH (2.3 %). This is found even after land use, soil type and rainfall have been considered, underscoring how urgently soil health should be addressed here. Our benchmarking framework allows landowners to compare where their measured soil health indicators fall within expected ranges and is applicable to other biomes, national and multinational contexts.

Cattle grazing profoundly affects abiotic and biotic characteristics of ecosystems. While most research has been performed on grasslands, the effect of large managed ungulates on forest ecosystems has largely been neglected. Compared to a baseline seminatural state, we investigated how long-term cattle grazing of birch forest patches affected the abiotic state and the ecological community (microbes and invertebrates) of the soil subsystem. Grazing strongly modified the soil abiotic environment by increasing phosphorus content, pH, and bulk density, while reducing the C:N ratio. The reduced C:N ratio was strongly associated with a lower microbial biomass, mainly caused by a reduction of fungal biomass. This was linked to a decrease in fungivorous nematode abundance and the nematode channel index, indicating a relative uplift in the importance of the bacterial energy-channel in the nematode assemblages. Cattle grazing highly modified invertebrate community composition producing distinct assemblages from the seminatural situation. Richness and abundance of microarthropods was consistently reduced by grazing (excepting collembolan richness) and grazing-associated changes in soil pH, Olsen P, and reduced soil pore volume (bulk density) limiting niche space and refuge from physical disturbance. Anecic earthworm species predominated in grazed patches, but were absent from ungrazed forest, and may benefit from manure inputs, while their deep vertical burrowing behavior protects them from physical disturbance. Perturbation of birch forest habitat by long-term ungulate grazing profoundly modified soil biodiversity, either directly through increased physical disturbance and manure input or indirectly by modifying soil abiotic conditions. Comparative analyses revealed the ecosystem engineering potential of large ungulate grazers in forest systems through major shifts in the composition and structure of microbial and invertebrate assemblages, including the potential for reduced energy flow through the fungal decomposition pathway. The precise consequences for species trophic interactions and biodiversity-ecosystem function relationships remain to be established, however.

Lumbricus friendi is a lumbricid earthworm mainly found in western Europe, considerably less well studied than its close relative L. terrestris and until now, has not been a subject of taxonomical debate. However, its disjointed geographical distribution suggesting striking similarities to the Celtic fringes and of the so-called "Lusitanian" species merits further investigation. Our aim was to examine the genetic variation of this species and other related taxa within the genus (L. terrestris, L. rubellus, L. rubellus friendoides and L. friendi bouchei) to test for the existence of cryptic lineages that might explain its current distribution. Using mitochondrial (16S and COI) and nuclear (Amplified Fragment Length Polymorphism, AFLP) markers, we provide the first genetic basis not only to support the recent claim that L. friendi bouchei should be elevated to species rank (L. bouchei Zicsi and Csuzdi 1999), but also to conclude that L. rubellus friendoides is a valid species too, deserving a new name (L. heracleus stat. nov.). In addition, the AFLP results indicated the existence of a high cryptic diversity within L. friendi populations, which lacked geographic structure, resulting in the French samples being genetically closer to those from Ireland and Wales than to the Spanish ones. Our findings further highlight the likelihood that L. friendi and L. bouchei might have been overlooked or confounded with L. terrestris/L. herculeus and question the reliability of L. friendi records reported in the literature and those deposited in museums and sequence libraries (we provide evidence that this seem to be the case with two examples). We therefore advocate for a better link between morphological diagnostic characters and molecular sequences and the taxonomical validation of museums' collections and sequence repositories.

Global land use change has resulted in more pasture and cropland, largely at the expense of woodlands, over the last 300 years. How this change affects soil hydraulic function with regard to feedbacks to the hydrological cycle is unclear for earth system modelling (ESM). Pedotransfer functions (PTFs) used to predict soil hydraulic conductivity (K) take no account of land use. Here, we synthesize >800 measurements from around the globe from sites that measured near-saturated soil hydraulic conductivity, or infiltration, at the soil surface, on the same soil type at each location, but with differing land use, woodland (W), grassland (G) and cropland (C). We found that texture based PTFs predict K reasonably well for cropland giving unbiased results, but increasingly underestimate K in grassland and woodland. In native woodland and grassland differences in K can usually be accounted for by differences in bulk density. However, heavy grazing K responses can be much lower indicating compaction likely reduces connectivity. We show that the K response ratios (RR) between land uses vary with cropland (C/W = 0.45 [W/C = 2.2]) and grassland (G/W = 0.63 [W/G = 1.6]) having about half the K of woodland.

Abstract. The Glastir Monitoring and Evaluation Programme (GMEP) ran from 2013 until 2016, and was probably the most comprehensive programme of ecological study ever undertaken at a national scale in Wales. The programme aimed to (1) set up an evaluation of the environmental effects of the Glastir agri-environment scheme and (2) quantify environmental status and trends across the wider countryside of Wales. The focus was on outcomes for climate change mitigation, biodiversity, soil and water quality, woodland expansion and cultural landscapes. As such, GMEP included a large field survey component, collecting data on a range of elements including vegetation, land cover and use, soils, freshwaters, birds and insect pollinators from up to 300 1 km squares throughout Wales. The field survey capitalised upon the UKCEH Countryside Survey of Great Britain, which has provided an extensive set of repeated, standardised ecological measurements since 1978. The design of both GMEP and the UKCEH Countryside Survey involved stratified-random sampling of squares from a 1 km grid, ensuring proportional representation from land classes with distinct climate, geology and physical geography. Data were collected from different land cover types and landscape features by trained professional surveyors, following standardised and published protocols. Thus, GMEP was designed so that surveys could be repeated at regular intervals to monitor the Welsh environment, including the impacts of agri-environment interventions. One such repeat survey is scheduled for 2021 under the Environment and Rural Affairs Monitoring and Modelling Programme (ERAMMP). Data from GMEP have been used to address many applied policy questions, but there is major potential for further analyses. The precise locations of data collection are not publicly available, largely for reasons of landowner confidentiality. However, the wide variety of available datasets can be (1) analysed at coarse spatial resolutions and (2) linked to each other based on square-level and plot-level identifiers, allowing exploration of relationships, trade-offs and synergies. This paper describes the key sets of raw data arising from the field survey at co-located sites, 2013 to 2016. Data from each of these survey elements are available with the following Digital Object Identifiers. Landscape features, https://doi.org/10.5285/82c63533-529e-47b9-8e78-51b27028cc7f, https://doi.org/10.5285/9f8d9cc6-b552-4c8b-af09-e92743cdd3de, https://doi.org/10.5285/f481c6bf-5774-4df8-8776-c4d7bf059d40; Vegetation plots, https://doi.org/10.5285/71d3619c-4439-4c9e-84dc-3ca873d7f5cc; Topsoil physico-chemical properties, https://doi.org/10.5285/0fa51dc6-1537-4ad6-9d06-e476c137ed09; Topsoil meso-fauna, https://doi.org/10.5285/1c5cf317-2f03-4fef-b060-9eccbb4d9c21; Topsoil particle size distribution https://doi.org/10.5285/d6c3cc3c-a7b7-48b2-9e61-d07454639656; Headwater stream quality metrics, https://doi.org/10.5285/e305fa80-3d38-4576-beef-f6546fad5d45 ; Pond quality metrics, https://doi.org/10.5285/687b38d3-2278-41a0-9317-2c7595d6b882; Insect pollinator and flower data, https://doi.org/10.5285/3c8f4e46-bf6c-4ea1-9340-571fede26ee8; Bird counts, https://doi.org/10.5285/31da0a94-62be-47b3-b76e-4bdef3037360.

Soil Quality or Soil Health are terms adopted by the scientific community as a metaphor for the effects of differing land management practices on the properties and functions of soil. Many other terms and metaphors are in use that defy neat quantification: human health, for example. Our challenge is to understand the importance of using such metaphors, but without compromising the underlying scientific understanding upon which they are based. We present here an approach based on expert elicitation in the field of soil quality and management, which offers a universal way of putting numbers to the metaphor. Like humans, soils differ and so do the ways in which they become unhealthy. We structure experts’ views of the extent to which soil delivers the functions expected of it within Bayesian Belief Networks anchored by measurable properties of soil. With these networks, we deduce the value of additional data to the precision of estimates of soil quality and health and infer the likely state of soil at locations in England & Wales. We conclude that the value of soil is best scored as its fitness for purpose or its utility. Our methodology has general applicability and could be deployed elsewhere or in other disciplines.