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In wetlands, a distinct zonation of plant species composition occurs along moisture gradients, due to differential flooding tolerance of the species involved. However, "flooding" comprises two important, distinct stressors (soil oxygen demand [SOD] and partial submergence) that affect plant survival and growth. To investigate how these two flooding stressors affect plant performance, we executed a factorial experiment (water depth x SOD) for six plant species of nutrient-rich and nutrient-poor conditions, occurring along a moisture gradient in Dutch dune slacks. Physiological, growth, and biomass responses to changed oxygen availability were quantified for all species. The responses were consistent with field zonation, but the two stressors affected species differently. Increased SOD increased root oxygen deprivation, as indicated by either raised porosity or increased alcohol dehydrogenase (ADH) activity in roots of flood-intolerant species (Calamagrostis epigejos and Carex arenaria). While SOD affected root functioning, partial submergence tended more to reduce photosynthesis (as shown both by gas exchange and 13C assimilation), leaf dark respiration, 13C partitioning from shoots to roots, and growth of these species. These processes were especially affected if the root oxygen supply was depleted by a combination of flooding and increased SOD. In contrast, the most flood-tolerant species (Juncus subnodulosus and Typha latifolia) were unaffected by any treatment and maintained high internal oxygen concentrations at the shoot : root junction and low root ADH activity in all treatments. For these species, the internal oxygen transport capacity was well in excess of what was needed to maintain aerobic metabolism across all treatments, although there was some evidence for effects of SOD on their nitrogen partitioning (as indicated by 865N values) and photosynthesis. Two species intermediate in flooding tolerance (Carex nigra and Schoenus nigricans) responded more idiosyncratically, with different parameters responding to different treatments. These results show that partial submergence and soil flooding are two very different stressors to which species respond in different ways, and that their effects on physiology, survival, and growth are interactive. Understanding species zonation with water regimes can be improved by a better appreciation of how these factors affect plant metabolism independently and interactively.

Abstract The question whether coexistence of marine renewable energy (MRE) projects and marine protected areas (MPAs) is a common spatial policy in Europe and how a number of factors can affect it, has been addressed by empirical research undertaken in eleven European marine areas. Policy drivers and objectives that are assumed to affect coexistence, such as the fulfillment of conservation objectives and the prioritization of other competing marine uses, were scored by experts and predictions were crosschecked with state practice. While in most areas MRE-MPA coexistence is not prohibited by law, practice indicates resistance towards it. Furthermore expert judgment demonstrated that a number of additional factors, such as the lack of suitable space for MRE projects and the uncertainty about the extent of damage by MRE to the MPA, might influence the intentions of the two major parties involved (i.e. the MRE developer and the MPA authority) to pursue or avoid coexistence. Based on these findings, the interactions of these two players are further interpreted, their policy implications are discussed, while the need towards efficient, fair and acceptable MRE-MPA coexistence is highlighted.

As a fast-growing food production industry, aquaculture is dealing with the need for intensification due to the global increasing demand for fish products. However, this also implies the use of more sustainable practices to reduce negative environmental impacts currently associated with this industry, including the use of wild resources, destruction of natural ecosystems, eutrophication of effluent receiving bodies, impacts due to inadequate medication practices, among others. Using multi-species systems, such as integrated multi-trophic aquaculture, allows to produce economically important species while reducing some of these aquaculture concerns, through biomitigation of aquaculture wastes and reduction of diseases outbreaks, for example. Applying mathematical models to these systems is crucial to control and understand the interactions between species, maximizing productivity, with important environmental and economic benefits. Here, the application of some equations and models available in the literature, regarding basic parameters, is discussed – population dynamics, growth, waste production, and filtering rate – when considering the description and optimization of a theoretical integrated multi-trophic aquaculture operation composed by three trophic levels.

This review gathers information about the current legal requirements related to the emission of ammonia and greenhouse gases from animal housing in 21 out of the 28 EU countries and in 5 non-EU countries. Overall the review shows that most of the included countries have established substantial procedures to limit ammonia emission and practically no procedures to limit greenhouse gas emission. The review can also be seen as an introduction to the substantial initiatives and decisions taken by the EU in relation to ammonia emission from animal housing, and as a notification on the absence of corresponding initiatives and decisions in relation to greenhouse gases. An EU directive on industrial emissions from 2010 and an implementation decision from 2017 are the main general instruments to reduce ammonia emission from animal housing in the EU. These treaties put limits to ammonia emissions from installations with more than 2000 places for fattening pigs, with more than 750 places for sows and with more than 40,000 places for poultry. As an example, the upper general limit for fattening pigs is 2.6 kg ammonia per animal place per year. This review indicates that the important animal producing countries in the EU have implemented the EU requirements, and, that only a few countries with a large pig population, in relation to their geographical size, have implemented requirements that are stricter than what is required by the EU.

In Europe the demand of biomass for the whole bioeconomy is increasing year by year. In some cases, this biomass come from non-European countries. The EU is already a net importer of biomass for bioenergy and imports could be even more relevant in the near future. Therefore, it is important to guarantee that this biomass supply from outside the EU is being done in a sustainable way and that negative environmental and socio-economic impacts are minimised. The project BioTrade2020plus has the aim of providing guidelines for the development of a European Bioenergy Trade Strategy for 2020 and beyond. It has analyzed in depth the role of lignocellulosic biomass (woody resources, agricultural residues and cellulosic crops) imports from six selected sourcing regions: North America (Southeast United States), South America (Brazil, Colombia), East Europe (Ukraine), Southeast Asia (Indonesia) and East Africa (Kenya). It has considered availability and sustainability constrains as well as existing strategies in these sourcing regions. All this info is being integrated in an interactive tool available on the BioTrade2020plus webpage. Proceedings of the 24th European Biomass Conference and Exhibition, 6-9 June 2016, Amsterdam, The Netherlands, pp. 1356-1363

AbstractThe recent rise in atmospheric methane (CH4) concentrations accelerates climate change and offsets mitigation efforts. Although wetlands are the largest natural CH4 source, estimates of global wetland CH4 emissions vary widely among approaches taken by bottom‐up (BU) process‐based biogeochemical models and top‐down (TD) atmospheric inversion methods. Here, we integrate in situ measurements, multi‐model ensembles, and a machine learning upscaling product into the International Land Model Benchmarking system to examine the relationship between wetland CH4 emission estimates and model performance. We find that using better‐performing models identified by observational constraints reduces the spread of wetland CH4 emission estimates by 62% and 39% for BU‐ and TD‐based approaches, respectively. However, global BU and TD CH4 emission estimate discrepancies increased by about 15% (from 31 to 36 TgCH4 year−1) when the top 20% models were used, although we consider this result moderately uncertain given the unevenly distributed global observations. Our analyses demonstrate that model performance ranking is subject to benchmark selection due to large inter‐site variability, highlighting the importance of expanding coverage of benchmark sites to diverse environmental conditions. We encourage future development of wetland CH4 models to move beyond static benchmarking and focus on evaluating site‐specific and ecosystem‐specific variabilities inferred from observations.

Abstract Cities are becoming increasingly vulnerable to flooding because of rapid urbanization, installation of complex infrastructure, and changes in the precipitation patterns caused by anthropogenic climate change. The present paper provides a critical review of the current state-of-the-art methods for assessing the impacts of climate change on precipitation at the urban catchment scale. Downscaling of results from global circulation models or regional climate models to urban catchment scales are needed because these models are not able to describe accurately the rainfall process at suitable high temporal and spatial resolution for urban drainage studies. The downscaled rainfall results are however highly uncertain, depending on the models and downscaling methods considered. This uncertainty becomes more challenging for rainfall extremes since the properties of these extremes do not automatically reflect those of average precipitation. In this paper, following an overview of some recent advances in the development of innovative methods for assessing the impacts of climate change on urban rainfall extremes as well as on urban hydrology and hydraulics, several existing difficulties and remaining challenges in dealing with this assessment are discussed and further research needs are described.

Climate Data Records of soil moisture are fundamental for improving our understanding of long-term dynamics in the coupled water, energy, and carbon cycles over land. To respond to this need, in 2012 the European Space Agency (ESA) released the first multi-decadal, global satellite-observed soil moisture (SM) dataset as part of its Climate Change Initiative (CCI) program. This product, named ESA CCI SM, combines various single-sensor active and passive microwave soil moisture products into three harmonised products: a merged ACTIVE, a merged PASSIVE, and a COMBINED active + passive microwave product. Compared to the first product release, the latest version of ESA CCI SM includes a large number of enhancements, incorporates various new satellite sensors, and extends its temporal coverage to the period 1978–2015. In this study, we first provide a comprehensive overview of the characteristics, evolution, and performance of the ESA CCI SM products. Based on original research and a review of existing literature we show that the product quality has steadily increased with each successive release and that the merged products generally outperform the single-sensor input products. Although ESA CCI SM generally agrees well with the spatial and temporal patterns estimated by land surface models and observed in-situ, we identify surface conditions (e.g., dense vegetation, organic soils) for which it still has large uncertainties. Second, capitalising on the results of > 100 research studies that made use of the ESA CCI SM data we provide a synopsis of how it has contributed to improved process understanding in the following Earth system domains: climate variability and change, land-atmosphere interactions, global biogeochemical cycles and ecology, hydrological and land surface modelling, drought applications, and meteorology. While in some disciplines the use of ESA CCI SM is already widespread (e.g. in the evaluation of model soil moisture states) in others (e.g. in numerical weather prediction or flood forecasting) it is still in its infancy. The latter is partly related to current shortcomings of the product, e.g., the lack of near-real-time availability and data gaps in time and space. This study discloses the discrepancies between current ESA CCI SM product characteristics and the preferred characteristics of long-term satellite soil moisture products as outlined by the Global Climate Observing System (GCOS), and provides important directions for future ESA CCI SM product improvements to bridge these gaps.