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Urban water security levels will be threatened during the next few years due to new development pressures combined with the climate emergency and increasing population growth in cities. In the UK, London’s planning authorities have a target of more than half a million households for the next 10 years. This new housing will increase the current impacts on urban consumer demand, flood risk, and river water quality indicators. In our previous work, we developed a new concept for urban Water Neutrality (WN) inside an integrated urban planning sustainability framework called CityPlan to deal with water stress and urban complexity issues. This framework integrates the UK’s planning application process with systemic design solutions and evaluation, all being spatially represented in a GIS platform. With the new digital era, there is a constantly increasing number of spatial datasets that are openly available from different sources, but most of them are disaggregated and difficult to understand by key urban stakeholders such as Local Planning Authorities, housing developers, and water companies. Moreover, there are several Multi-Criteria Decision Support Tools (MCDST) that address water management challenges in the literature; but there is still little evidence of one that evaluates the impacts and opportunities to allocate water neutral urban developments.In this work, we expand the CityPlan framework and present an innovative fully data-driven approach to test WN indicators at different urban scales. WaNetDST integrates GIS spatial data with a series of rules for development impact and offset opportunity based on the current properties of the urban land. This integration is linked to a new scoring system from expert advice that maps strategic areas for water neutral interventions and links the most impactful zones with others more prone to be intervened. The tool connects different urban scales with a series of case study areas: from city (i.e., London), to borough (i.e., Enfield), and to urban development scale (i.e., Meridian Water Development). In the end, WaNetDST visually compares the need for housing vs. green spaces and the trade-offs between new housing vs. retrofitting existing infrastructure, providing a series of maps that guide the planning decision-making process in an integrated way. The results from CityPlan might potentially change the decision-making process for LPAs and housing developers and open a new dialogue between boroughs inside the same city, providing a novel and automated system for WN trade-offs and linking data-driven design with future planning decisions

During COP14 in 2022, Ramsar Convention commended 25 cities around the world for their efforts to protect urban wetlands. With the development of cities and the increase in land demand, the trend is to reduce the number of open blue spaces. Yet when preserved and sustainably used, urban nature-based solutions in the form of constructed wetlands could provide water management benefits including water quality regulation and flood mitigation. However, these water management benefits have rarely been evaluated at a catchment scale, and the mechanisms behind them are not fully understood, both of which hinder effective integrated constructed wetlands planning. We aim to explore the impact of wetland changes on water quality and quantity at the catchment scale. This study firstly evaluates the benefits by analysing the monitoring water quantity and quality datasets before and after the wetland construction in Enfield catchment, London. To understand the mechanisms behind the benefits, we build a Water Systems Integration Modelling framework (WSIMOD) to simulate the catchment-scale water cycle. This model is validated against monitoring river flow and water quality data. The constructed wetlands are then conceptualised and integrated into the WSIMOD, and their interactions with the catchment water cycle are simulated. Scenarios are constructed to analyse the impacts of different configurations and sizes of the constructed wetlands on the catchment water cycle. The results show that urban wetlands play a role in flood detention and water quality purification of watershed water resources at the catchment scale. Scattered small wetlands can more effectively reduce the impact of a flood under the same total wetland area. The results provide useful insights into the planning of constructed wetlands for maximising the water management benefits at a catchment scale. Future studies could focus on representing the interaction between the quantity and quality of water in a wetland with biodiversity and leveraging this representation to design interventions to improve biodiversity.

Ponds and the adjacent green spaces are an important part of urban blue-green Infrastructure (BGI) and contribute to a number of ecosystem services, including alleviation of flood risk, amelioration of climatic fluctuations, and improvement of runoff water quality, as well as biodiversity and amenity values. Multiple benefits associated with urban ponds have only recently started to be appreciated, and examples of in-depth interdisciplinary insights remain rare. This paper gives an account of the ecosystem services provided by Blackford Pond, a semi-natural water body located within a nature reserve and nominated as a site globally important for scientific research. Despite elevated levels of polluting substances and eutrophication, the overall species richness of the site is high and the biodiversity of the locality is enhanced by the ecotone effect. The diversity of available plant hosts and substrates appears to benefit the fungal community and the abundance of aquatic invertebrate fauna appears to benefit the higher trophic levels. Hydrological modelling clearly shows that the pond increases the flood resilience of the surrounding area, despite not having been designed as a drainage feature. The application of the Natural Capital Planning Tool (NCPT) also reveals higher values (in relation to the values of amenity grassland) of such ecosystem services categories as biodiversity (+4.76 per hectare), aesthetic values (+4.67), flood risk regulation (+0.41), air quality (+0.28), local (+0.6) and global (+0.14) climate regulations. The discussion highlights a number of trade-offs among different ecosystem services (e.g. water quality vs. diatom research value, flood resilience vs. air quality and carbon capture, biodiversity of ectomycorrhizal vs. lichenised fungi), and considers which of the multiple benefits provided by the site may have not been fully reflected in NCPT calculations or the economic estimates obtained using contingent valuation (e.g. effects on hydrology, water quality, wildlife corridors, education and research value). The simultaneous consideration of biodiversity, hydrology, water chemistry and amenity, education, research and other values presented in this paper contributes towards a better understanding of the ecology and overall functioning of urban ponds, and helps to increase appreciation of their benefits and promote their public acceptability and further implementation.

Cities are open living systems, which rely on the confluence of multiple layers of infrastructure and corresponding services. The interaction among these components is made even more complex by the demands of businesses and governments, together with constraints arising from ecological and environmental considerations. Climate change-related phenomena are putting an enormous strain on cities’ infrastructure, basic services, human livelihoods, public health and well-being. In many parts of the world concerns mount in regard to the scarcity of resources and growing risk of natural disasters (heat waves, urban flooding, droughts). The converse also holds true, cities are major contributors to climate change through greenhouse gas emissions, notwithstanding other sources of pollution. This, together with the increase in urban growth and urbanization, results in an expansion of urban hazards - including water pollution, disease spread and issues with food security. Despite these pressing issues, we are witnessing an almost paradoxical mismatch between the needs of future cities and the practices currently used in numerous urban projects. A wholesale re-thinking of existing urban design methods at systems level (Systemic Design), is therefore not only necessary, but also provides significant opportunities to explore critical aspects of Blue-Green Infrastructure (BGI) and systematic assessment of possible future scenarios of different scales (local, urban, regional…). Nature-based solutions (NBS) are at the very core of the conception and development of BGI and provide a range of ecosystem services including alleviation of flood risk, mitigation of climatic effects, increase in biodiversity and amenity values, improvements in water quality, and further, rather more intangible benefits related to the residents’ health and wellbeing.In this work we provide a systemic design as an innovative and integrated approach, based on ecology and ecological design, which introduces the systematic context analysis (environmental, climatic, historic…). A GIS-based mapping of the context, produced in relation to the functional purpose, can give us synthetic prospects to better understand the potential effectiveness of BGI solutions (design options) in relation to their wider ecosystem. The systemic design approach allows an examination of possible steps to reduce actual cities vulnerability and to explore the main drivers of urban development, climate change mitigation and urban resilience. In this way, the systemic design approach also supports decisions for further planning and anticipates actions for the management of the multifaceted hazards of the entire urban system.

This paper gives an account of multiple benefits provided by Granton SUDS pond and discusses their relevance to the alleviation of environmental, economic and social risks. The pond was established in 2005 and is situated in a park, close to a supermarket and a college. It has an area of approximately 2600 m2 and a hydrographic survey carried out as part of this research provided an estimate for the pond’s volume of 1904 m3 for the normal operating conditions. However, during flooded conditions (also observed during this research) the pond’s volume increases to circa 2545 m3. The pond has considerable biodiversity value and an important amenity function. The locality is enjoyed daily by many visitors and is particularly popular with joggers, dog walkers and families. Modelling of the pond’s catchment was undertaken using the hydrodynamic model CityCAT coupled with the hydrological model SHETRAN. Changes in water discharge from the pond were simulated using the time series of precipitation and air temperature data obtained from the Scottish Environment Protection Agency (SEPA). The discharge is higher in winter, which determines shorter retention times. That has implications for the observed dynamics of the hydrobiological community, with higher risk of cyanobacterial development in the summer. However, according to the ICP MS analysis of water chemistry, the observed planktonic community and the biological water quality estimated by macroinvertebrate sampling, are all broadly similar to those in other ponds. CityCAT results show that the presence of the pond delays and reduces the peak discharge after extreme precipitation events, with reductions being greater for smaller events. This study contributes to accumulating evidence of interlinkages among hydrology, ecology, biogeochemistry and biological water quality at the SUDS ponds sites, thus underlying the need for a comprehensive simultaneous consideration of their subsystems. These aspects are indispensable for reducing the risk of negative environmental effects and vital for planning future urban developments and nature-based solutions, as well as for the management of existing SUDS assets.

Contaminated runoff from industrial estates is a significant cause of poor quality in receiving watercourses. Pollution risk begins at each of the industrial premises, presenting different environmental risks which require individual treatment and contingency plans. This is best achieved using SUDS technology, which adds green infrastructure with passive drainage features to the existing drainage and treatment systems, designed to capture the pollutants present in runoff at source on individual sites, for conveyance and on a regional basis serving the whole estate. Here, we develop a multistage investigative framework structured to facilitate the search for relevant solutions and optimization of their design. This paper presents the results of the awareness survey, identifies barriers and opportunities, and reports on case studies dealing with potential SUDS retrofits at industrial facilities, assessing the existing control measures and the scope for new ones with the aim of improving pollution management. The feasibility of SUDS components was assessed with respect to their functional characteristics, economic costs, and logistical constraints. Lack of knowledge related to SUDS and pollution prevention legislation was identified as the major barrier to retrofits, which should be addressed through educational measures. Although comprehensive SUDS retrofits could be prohibitive in cost for small and medium-sized companies, partial and affordable retrofit solutions can be easily implemented to achieve the environmental benefits sought. In addition to the improvements in water quality and alleviation of flood risk, the introduction of Blue-Green Infrastructure will bring about further multiple benefits related to such ecosystem services as the amelioration of the local climate, reduction of noise, improvements in air quality, enhancement of the local biodiversity, and positive effects for the human well-being and mental health.

Blue-green infrastructure (BGI) ponds have an important function of alleviating flood risk and provide water quality improvements among other multiple benefits. Characterisation of bottom sediments and suspended particulate matter (SPM) is understudied, but is indispensable for assessing the ponds' functioning because of their role in biogeochemical cycling and pollutant adsorption. Here we report on the analysis of particle sizes and chemistry from multiple locations. The results have shown that SPM in these ponds includes particles of both biological and abiotic origin, and the in situ produced organic matter constitutes a major part of SPM. The relevance of biological processes is often overlooked, but a combination of scanning electron microscopy (SEM) observations and chemical analysis highlights its primary importance for characterisation of the particulate matter. A considerable proportion of both suspended and sedimented particulates is smaller than 100 microns. There is normally a large fraction of small silt-sized particles, and often a considerable proportion of very fine particles (clay-size). Although for some spectra unimodal distribution has been observed, in many cases the revealed particle size distribution (PSD) was bimodal, and in some instances more than two modes were revealed. A complex PSD would be expected to result from a combination of simple unimodal distributions. Hence the multimodality observed may have reflected contributions from different sources, both abiotic and biological. Furthermore, many smaller particles appear to be interconnected by detrital matter. Among chemical elements routinely detected within the SPM in significant concentrations were Si, Al, Ca, Mg, Fe, K, Mn, P, Cl and S. In a number of cases, however, there were less expected elements such as Ti, Y, Mo, Cr and even Au; these may have reflected the effect of car park and road runoff and/or industrial pollution. Most of these elements (except Mo and Au) and up to 30 others were also routinely detected in sediment samples. Such pollutants as Co, Cu, Ni, Zn and As were detected in bottom sediments of all ponds. There were a number of correlations between pollutants in sediments and the particle's median diameter. However, aggregation leads to large low density flocks and masks correlation of chemicals with SPM particle size. Statistical associations among the elements aided the understanding of their sources and pathways, as well as the underlying biological and abiotic processes. Specifically, our analysis implicated contributions from such sources as allochthonous and autochthonous detritus, roadside and industrial pollution, biologically induced precipitation, and discarded electronics. Elevated levels of rare earth elements (REE) and other trace elements open a possibility of their recovery from the sediments, which should be considered among the multiple benefits of BGI.

This paper provides a summary of ecological functioning, biodiversity and water chemistry of two sustainable drainage systems (SuDS) ponds, and compares the level of ecosystem services with those attainable by retrofitting green roofs (GRs) in the ponds’ catchments. These study sites are characterised by relatively high diversity of habitats, including aquatic, mesic and terrestrial; the importance of the latter is highlighted using the analysis of vascular plants and calcicolous lichens. Both SuDS sites provide valuable multiple benefits related to the enhancement of local biodiversity, water quality improvement and alleviation of flood risk, and the retrofitting of GRs would further enhance flood resilience and biodiversity of the area. However, there might be potentially negative effects on the runoff water quality and hydrobiological community composition of the receiving ponds. Changes in the runoff chemistry combined with the decreases in flush rate of high-flow events would increase the risk of cyanobacterial dominance during late summer and autumn. Such trade-offs should be carefully considered in planning any practical actions. This study elucidates indirect effects by following the methodological framework of comparative ecosystem analysis, which will be of use for any research and applications considering implementation of complex nature-based solutions (NBS), including those within the context of sustainable development of blue-green cities (BGC).

Soil erosion by water is the most important global environmental problem. A modern system for assessing and monitoring soil erosional degradation should be based on the use of remote sensing data. This raises the issue of correct data decoding. The article proposes a method for visual interpretation of eroded soils according to the Sentinel image obtained in the visible range. The authors give some combinations of decoding signs to determine the manifestations of linear and surface water erosion from images. The article shows possible errors in decoding the manifestations of water erosion and gives an example of assessing the erosion of the soil cover based on the results of decoding the Sentinel-2 satellite image. Moderately and heavily eroded soils are reliably distinguished, the area of which, according to the interpretation data, was 2.4% of the area of arable land in the studied territory. In the future, the obtained sample of spectral images of eroded soils can be used to develop an automated method of interpretation based on the principle of "computer vision".

The main pond within the historic Royal Botanic Garden Edinburgh is an important component of urban blue-green infrastructure. This paper reports on flood resilience provided by the pond (simulated using the CityCAT hydrodynamic model), its water residence times (obtained using the Shetran hydrological model), and the ecology and biodiversity (vascular plants, bryophytes, aquatic invertebrates, phyto- and zooplankton, birds) of the pond and the adjacent area. The results show that the pond improves the flood resilience with at least a 27% reduction in the peak discharge during a 1 h, one in 100-year event. The area represents a biodiversity hot spot with a range of native taxa occurring among introduced plant species. The plankton community is dominated by diatoms, reflecting elevated levels of turbulence and a relatively short residence time, with an average value of 10 days. Analysis of macroinvertebrate community indicates a potential for water quality improvement. The results are discussed in relation to multiple societal benefits related to flood resilience, recreation, education, water quality, amenity and biodiversity value. The conclusions may prove particularly valuable for introducing practical measures in the water catchment, preventing waterlogging of the soil and ensuring an uninterrupted supply of public services. This article is part of the theme issue ‘Urban flood resilience'.

Achieving urban flood resilience at local, regional and national levels requires a transformative change in planning, design and implementation of urban water systems. Flood risk, wastewater and stormwater management should be re-envisaged and transformed to: ensure satisfactory service delivery under flood, normal and drought conditions, and enhance and extend the useful lives of ageing grey assets by supplementing them with multi-functional Blue-Green infrastructure. The aim of the multidisciplinary Urban Flood Resilience (UFR) research project, which launched in 2016 and comprises academics from nine UK institutions, is to investigate how transformative change may be possible through a whole systems approach. UFR research outputs to date are summarised under three themes. Theme 1 investigates how Blue-Green and Grey (BG + G) systems can be co-optimised to offer maximum flood risk reduction, continuous service delivery and multiple co-benefits. Theme 2 investigates the resource capacity of urban stormwater and evaluates the potential for interoperability. Theme 3 focuses on the interfaces between planners, developers, engineers and beneficiary communities and investigates citizens’ interactions with BG + G infrastructure. Focussing on retrofit and new build case studies, UFR research demonstrates how urban flood resilience may be achieved through changes in planning practice and policy to enable widespread uptake of BG + G infrastructure.

Preliminary results of the UK Urban Flood Resilience research consortium are presented and discussed, with the work being conducted against a background of future uncertainties with respect to changing climate and increasing urbanization. Adopting a whole systems approach, key themes include developing adaptive approaches for flexible engineering design of coupled grey and blue-green flood management assets; exploiting the resource potential of urban stormwater through rainwater harvesting, urban metabolism modelling and interoperability; and investigating the interactions between planners, developers, engineers and communities at multiple scales in managing flood risk. The work is producing new modelling tools and an extensive evidence base to support the case for multifunctional infrastructure that delivers multiple, environmental, societal and economic benefits, while enhancing urban flood resilience by bringing stormwater management and green infrastructure together.

Growing urban populations, changes in rainfall patterns and ageing infrastructure represent significant challenges for urban water management (UWM). There is a critical need for research into how cities should adapt to become resilient to these impacts under uncertain futures. UWM challenges in the Ebbsfleet Garden City (UK) were investigated via a participatory process and potential sustainable solutions were explored using a System Dynamics Model (SDM). Collaborative development of the SDM by the Ebbsfleet Learning and Action Alliance developed stakeholders’ understanding of future UWM options and enabled a structured exploration of interdependencies within the current UWM system. Discussion by stakeholders resulted in a focus on potable water use and the development of the SDM to investigate how residential potable water consumption in the Ebbsfleet Garden City might be reduced through a range of interventions, e.g., socio-environmental and economic policy incentives. The SDM approach supports decision-making at a strategic, system-wide level, and facilitates exploration of the long-term consequences of alternative strategies, particularly those that are difficult to include in quantitative models. While an SDM can be developed by experts alone, building it collaboratively allows the process to benefit from local knowledge, resulting in a collective learning process and increased potential for adoption.

This paper presents the research carried out in the marine renewables group of Heriot-Watt University, where the physical models of wave energy converters are first tested in the wave basin, and the results of their behaviour are then compared to the simulations performed using mathematical modelling. An OrcaFlex model is used to assess the scouring effect on bottom sediments and consequent disruption of benthic habitats, and open water tests are being conducted to compare the model performance with the actual observations. The output from OrcaFlex is then imported to Matlab, where the affected area is calculated using the time series of coordinates of touch down points of the mooring lines. The results show that the area of benthic habitats adversely affected by the leading mooring line on a typical wave energy converter (WEC) monotonically increases with the increase in wave height. In regular waves of 6 m height and 8 s period, the area of benthic habitats adversely affected by the mooring lines may exceed 60 m2. In addition to the direct effect on benthic habitats, sediment erosion by mooring lines will effect a whole range of ecosystem processes, e.g. due to changes in biogeochemical cycling and light penetration. These issues should be given a due consideration in calculations of ecological risks and EIA of any moored objects.

Measurements of concentrations of easily extractable soil nitrogen (N) were carried out on samples collected at the Heron Wood Reserve, Scotland, concurrently with investigations of N associated with total microbial biomass and the abundances of bacteria, fungi, and invertebrates. Soil biota at the studied site appeared to be limited by N. There was a remarkable difference between the ambient (i.e., easily extractable N) and biomass nitrogen. The abundance data of bacteria, protozoa and nematodes significantly negatively correlated with ambient N but showed positive correlations with the total microbial N content. There were, however, remarkable differences between the correlation patterns exhibited by the fungal and the bacterial pathways, as fungi did not show any correlations with chemical variables. These differences should be taken into account whilst interpreting biological interactions both at this important site and elsewhere.

Most of the wildfires in upland Britain occur in Spring, with the highest peak in April. However, the highest values of the Met Office Fire Severity Index (MOFSI, based on the Canadian Forest Fire Weather Index System) occur in the height of summer, thus successfully predicting extreme fire weather conditions, but failing to predict when the majority of real fires occur. Here we illustrate this discrepancy with data from the English Peak District, and present an alternative model which calculates a proposed shrub fire index (SFI) and compares it with randomly generated numbers to simulate fire occurrence. The major peaks in the SFI dynamics occur in spring, reflecting the effect of drought stress on shrubs caused by damaged leaf cuticles during winter and the lack of resources to alleviate the damage during the pre-green-up period. The model presented here shows a reasonable performance in reproducing the seasonal distribution of wild fire occurrence, and may therefore prove helpful for future development of a fire prediction system designed specifically for British conditions. An effective wildfire prediction system will have great value for increasing the preparedness of land managers, National Park Authority staff and the Fire and Rescue Services. A weather index that accurately predicts the fuel moisture content of the dominant shrubs will also be valuable to land managers who use prescribed fire for vegetation management.

In pycnoclines, the density differences can cause light scattering —schlieren —even though only few particulate scatterers may be present. This may pose problems for the interpretation of results obtained with instruments relying on light scattering and transmission, for example the LISST (Laser In Situ Scattering and Transmissometry) particle sizer, and various cameras. Here, the influence of schlieren on in situ forward light scattering, beam attenuation and image analysis is evaluated using a LISST-100 and a digital floc camera. Automated image analysis routines detect schlieren as particles, causing an apparent increase in particle size and volume. Re-analysis omitting schlieren-affected parts of the images reveals no increase. LISST beam attenuation and Volume Scattering Function (VSF) measurements indicate that schlieren can cause increases in beam attenuation due to a marked increase in the VSF at angles smaller than ~1.5°-2°, and falsely indicate accumulation of suspended particles in the pycnocline. Light scattering caused by density differences can also cause multiple scattering, which produces an apparent decrease in particle size derived from the LISST. Schlieren is visible in images when the buoyancy frequency exceeds ~0.12 s−1. Buoyancy frequencies above 0.025 s−1 may cause increases in beam attenuation due to scattering from the density gradients and complete extinction of beam transmission can occur at buoyancy frequencies above ~0.20 s−1. All instruments measuring light scattering can potentially be affected by density differences, and results obtained in waters where buoyancy frequencies exceeds 0.025 s−1 should be interpreted carefully.

Here we report on ecology and biodiversity of fungi in a unique mycological sanctuary in Britain, where data on species composition have been collected since 1994. To complement the biodiversity data by the information on the fungal ecological interactions and their role in the overall ecosystem functioning, soil properties and the composition of forest litter and field layer, bacterial population numbers and fungal biomass (in terms of ergosterol) were measured in 8 plots covered with different vegetations (beech, birch, birch-oak-beech, grass) over a May–Aug. period, and the results were analysed by correlation analysis and stepwise regression modelling together with data on protozoa and nematodes available from parallel research. The results highlighted the complexity of factors influencing temporal dynamics and spatial variability of fungal biomass in soil and forest litter. Most of the registered interactions appeared to be transient, and this should be taken into account while interpreting environmental observations. Interpretation of the specific relationships is given and implications for further research and overall ecosystem functioning are discussed.

Abstract Microinvertebrate abundance was measured, together with forest soil properties and litter components in eight plots dominated by beech and birch during May to August 2001. The results were analysed using ANOVA, stepwise regression and correlation analysis. Both protozoa and nematodes were analysed according to their functional groups. The protozoa were flagellates, ciliates and naked amoebae, and the nematodes were microbial and plant feeding nematodes. Moisture levels were between 28% and 33% in soil, and 50% to 70% in litter. Population numbers were very variable between sites and dates, and showed variable levels between May and July followed by a significant increase in August.ANOVA showed significant site and date effects, mainly in the litter. Stepwise regression models and correlation analysis revealed a number of interactions among separate groups of protozoa and nematodes, as well as their interrelations with fungi and bacteria. In addition, statistical analysis of soil data revealed a number of microfaunal relationships with soil pH, moisture and organic content, whilst in the field layer a number of significant interactions with specific forest litter fractions were found.The results have revealed particularly high levels of microfaunal abundance in the litter fraction compared to the soil, with flagellates and microbial feeding nematodes showing the highest levels among the trophic groups studied. These data compare well with other studies in similar ecosystems. The invertebrates present appear to be concentrated in hotspots of biological activity. In soil, they may predominantly have been confined to the rhizosphere. In the litter, their numbers may have been enhanced by nutrient availability, which may have increased throughout the study period owing to the gradual progress of decomposition facilitated by the combination of faunal, bacterial and fungal activity.

Summary The composition of forest litter and understorey layer, and fungal biomass (in terms of ergosterol) were measured in eight subplots over a winter – spring period (January to April). The sampling site was positioned in a range of woodland habitats (variously dominated by beech, Fagus sylvatica ; birch, Betula pendula × pubescens , and oak Quercus petraea ) and a clear area covered with grass (dominated by Holcus lanatus ). The results were analysed together with data on bacteria and microinvertebrates available from parallel research. Levels of ergosterol in individual subplots ranged between 50 and 160 µ g g − 1 DW. Fungal biomass decreased in March, and then increased signifi cantly in April. Stepwise regression models for ergosterol indicated positive relationships with moisture content (February), bacteria (all but February and March), fl agellates (February) and plant-feeding nematodes and fl ies (January, overall). The relationships with roots, seeds, the collective variable ‘ other microinvertebrates ’ (all March), amoebae (February) and fragments (March, overall) were negative, while the relationship between fungi- and microbial-feeding nematodes changed sign between February ( − ) and March (+). Results of analysis of covariance for fungal ergosterol were signifi cant only for January and the combined dataset. In January, fungi were shown to be signifi cantly related to amoebae, bacteria and a collembolan Folsomia candida , while the only signifi cant predictor returned by the overall model was bacteria. Correlation analysis confi rmed some effects already noted, and revealed a number of further interactions. The results highlighted the complexity of factors infl uencing temporal dynamics and spatial variability of

Abstract The micro and meso-invertebrate abundance was measured, together with forest litter composition, in eight plots of differing vegetation (dominated by beech and birch) over a winter-spring period. The litter moisture content was a mean of 76% during the sampling period and the beech sites were the driest. The results were analysed using a suite of statistical techniques, together with data on protozoa, fungi and bacteria available from parallel research. Nematodes were analysed according to the trophic levels, which included microbial feeders, plant feeders and predators. The majority of arthropods found were the collembolan, Folsomia candida and cryptostigmatid mites, with very small quantities of other micro- and mesoarthropods (such as larvae and mesostigmatid mites). The microarthropod populations peaked in January and fell during subsequent months, while population numbers of nematodes showed a decrease between January and February, followed by an increase in March. ANOVA showed a significant date effect, but no site-date interactions for the population abundance of both nematodes and microarthropods. Ecological interactions of meiofauna were analysed by ANCOVA, stepwise regression, and correlation analysis. Examples of relationships revealed include positive relationships of plant-feeding nematodes (PFN) with microbial feeding nematodes (MFN), and of F. candida with cryptostigmatid mites. Other positive interactions were found for PFN, MFN, F. candida, cryptostigmatid and mesostigmatid mites with litter components, such as beech leaves and litter thickness, moisture and grass, and protozoa. Negative interactions were recorded for PFN, MFN, F. candida, cryptostigmatid and mesostigmatid mites with beech leaves, fungi, protozoa and bacteria. The results have highlighted a very complex structure of factors influencing the temporal and spatial dynamics of the forest litter community. It is suggested that temperature and moisture content particularly influence the invertebrates present. The invertebrates appear to be present in a range of microhabitats, which may have resulted in a reduced level of competition and a high level of positive interactions revealed.

Wild fires are a serious problem affecting many terrestrial ecosystems and causing substantial economic damage. The occurrence and intensity of wildfire depend (in part) on the availability and characteristics of fuel, which in natural landscapes is predominantly represented by plant litter and live vegetation. Therefore, a comprehensive collation of the information relevant to plant/litter fuel complexes, fire occurrences, and their responses to changes in environmental conditions is needed to enhance our understanding of this phenomenon. This paper provides a brief overview of modelling approaches used for analyses of wildfire fuels, and argues the case for an object orientated database of fuel complexes, which is being developed within the ‘Fire Paradox’ project (http://www.fireparadox.org/project_summary.php).

International audience; Wildfires are a serious problem affecting many terrestrial ecosystems and causing substantial economic damage. Understanding the variation in structure of fuels (which are predominantly represented by plant litter and live vegetation) is key to understanding the behaviour of wildland fires. An understanding of changes to fuels as vegetation develops is also central to the management of both wildfire and the planning of prescribed burning. A description of fuel structure is required for all models of fire behaviour. It is therefore important that we have an appropriate system for describing fuel structure and predicting how fuel structure will develop through time (i.e. fuel succession). In this paper we review the range of published models used for fuel description and fuel succession. We propose an object-orientated database as an appropriate method for storing the complex data structures that are needed to process and analyse data on fuels. The potential advantages of an object-orientated database as a tool for modelling fuel succession are discussed