Understanding the role of biodiversity in the climate, food, water, energy, transport and health nexus in Europe.

Biodiversity underpins the functioning of ecosystems and the diverse benefits that nature provides to people, yet is being lost at an unprecedented rate. To halt or reverse biodiversity loss, it is critical to understand the complex interdependencies between biodiversity and key drivers and sectors to inform the development of holistic policies and actions. We conducted a literature review on the interlinkages between biodiversity and climate change, food, water, energy, transport and health ("the biodiversity nexus"). Evidence extracted from 194 peer-reviewed articles was analysed to assess how biodiversity is being influenced by and is influencing the other nexus elements. Out of the 354 interlinkages between biodiversity and the other nexus elements, 53 % were negative, 29 % were positive and 18 % contained both positive and negative influences. The majority of studies provide evidence of the negative influence of other nexus elements on biodiversity, highlighting the substantial damage being inflicted on nature from human activities. The main types of negative impacts were land or water use/change, land or water degradation, climate change, and direct species fatalities through collisions with infrastructure. Alternatively, evidence of biodiversity having a negative influence on the other nexus elements was limited to the effects of invasive alien species and vector-borne diseases. Furthermore, a range of studies provided evidence of how biodiversity and the other nexus elements can have positive influences on each other through practices that promote co-benefits. These included biodiversity-friendly management in relevant sectors, protection and restoration of ecosystems and species that provide essential ecosystem services, green and blue infrastructure including nature-based solutions, and sustainable and healthy diets that mitigate climate change. The review highlighted the complexity and context-dependency of interlinkages within the biodiversity nexus, but clearly demonstrates the importance of biodiversity in underpinning resilient ecosystems and human well-being in ensuring a sustainable future for people and the planet.

Development of soil health benchmarks for managed and semi-natural landscapes.

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.

Comment on Pescott & Jitlal 2020: Failure to account for measurement error undermines their conclusion of a weak impact of nitrogen deposition on plant species richness.

Estimation of the impacts of atmospheric nitrogen (N) deposition on ecosystems and biodiversity is a research imperative. Analyses of large-scale spatial gradients, where an observed response is correlated with measured or modelled deposition, have been an important source of evidence. A number of problems beset this approach. For example, if responses are spatially aggregated then treating each location as statistically independent can lead to biased confidence intervals and a greater probably of false positive results. Using methods that account for residual spatial autocorrelation, Pescott & Jitlal (2020) re-analysed two large-scale spatial gradient datasets from Britain where modelled N deposition at 5 × 5 km resolution had been previously correlated with species richness in small quadrats. They found that N deposition effects were weaker than previously demonstrated leading them to conclude that "previous estimates of Ndep impacts on richness from space-for-time substitution studies are likely to have been over-estimated". We use a simulation study to show that their conclusion is unreliable despite them recognising that an influential fraction of the residual spatially structured variation could itself be attributable to N deposition. This arises because the covariate used was modelled N deposition at 5 × 5 km resolution leaving open the possibility that measured or modelled N deposition at finer resolutions could explain more variance in the response. Explicitly treating this as spatially auto-correlated error ignores this possibility and leads directly to their unreliable conclusion. We further demonstrate the plausibility of this scenario by showing that significant variation in N deposition at the 1 km square resolution is indeed averaged at 5 × 5 km resolution. Further analyses are required to explore whether estimation of the size of the N deposition effect on plant species richness and other measures of biodiversity is indeed dependent on the accuracy and hence measurement error of the N deposition covariate. Until then the conclusions of Pescott & Jitlal (2020) should be considered premature.

Research challenges for cultural ecosystem services and public health in (peri-)urban environments.

Urbanization is a global trend, and consequently the quality of urban environments is increasingly important for human health and wellbeing. Urban life-style is typically associated with low physical activity and sometimes with high mental stress, both contributing to an increasing burden of diseases. Nature-based solutions that make effective use of ecosystem services, particularly of cultural ecosystem services (CES), can provide vital building blocks to address these challenges. This paper argues that, the salutogenic, i.e. health-promoting effects of CES have so far not been adequately recognised and deserve more explicit attention in order to enhance decision making around health and wellbeing in urban areas. However, a number of research challenges will need to be addressed to reveal the mechanisms, which underpin delivery of urban CES. These include: causal chains of supply and demand, equity, and equality of public health benefits promoted. Methodological challenges in quantifying these are discussed. The paper is highly relevant for policy makers within and beyond Europe, and also serves as a review for current researchers and as a roadmap to future short- and long-term research opportunities.

The role of 'Big Society' in monitoring the state of the natural environment.

Environmental monitoring is essential for assessing the current state of the environment, measuring impacts of environmental pressures and providing evidence to government. Recent UK government announcements have indicated an increased role for 'Big Society' in monitoring. In this paper, we review available literature concerning the use of citizen science for monitoring, present examples of successful volunteer monitoring work and highlight important issues surrounding the use of volunteers. We argue that in order to ensure that environmental monitoring continues to be effective it is important to learn from examples where volunteers are currently used, acknowledging constraints and identifying potential approaches which will help to maximise both their engagement and data quality. Effective partnerships between environmental monitoring organisations and volunteers may thus aid the UK in developing robust coordinated monitoring systems that will be less vulnerable to funding variances.

Biotic homogenization and changes in species diversity across human-modified ecosystems.

Changing land use and the spread of 'winning' native or exotic plants are expected to lead to biotic homogenization (BH), in which previously distinct plant communities become progressively more similar. In parallel, many ecosystems have recently seen increases in local species (alpha-) diversity, yet gamma-diversity has continued to decline at larger scales. Using national ecological surveillance data for Great Britain, we quantify relationships between change in alpha-diversity and between-habitat homogenizations at two levels of organization: species composition and plant functional traits. Across Britain both increases and decreases in alpha-diversity were observed in small random sampling plots (10-200m2) located within a national random sample of 1km square regions. As alpha-diversity declined (spatially in 1978 or temporally between 1978 and 1998), plant communities became functionally more similar, but species-compositional similarity declined. Thus, different communities converged on a narrower range of winning trait syndromes, but species identities remained historically contingent, differentiating a mosaic of residual species-poor habitat patches within each 1km square. The reverse trends in beta-diversity occurred where alpha-diversity increased. When impacted by the same type and intensity of environmental change, directions of change in alpha-diversity are likely to depend upon differences in starting productivity and disturbance. This is one reason why local diversity change and BH across habitats are not likely to be consistently coupled.