While progress has been made in reducing external nutrient inputs to the Baltic Sea, further actions are needed to meet the goals of the Baltic Sea Action Plan (BSAP), especially for the Baltic Proper, Gulf of Finland, and Gulf of Riga sub-basins. We used the net anthropogenic nitrogen and phosphorus inputs (NANI and NAPI, respectively) nutrient accounting approach to construct three scenarios of reduced NANI-NAPI. Reductions assumed that manure nutrients were redistributed from areas with intense animal production to areas that focus on crop production and would otherwise import synthetic and mineral fertilizers. We also used the Simple as Necessary Baltic Long Term Large Scale (SANBALTS) model to compare eutrophication conditions for the scenarios to current and BSAP-target conditions. The scenarios suggest that reducing NANI-NAPI by redistributing manure nutrients, together with improving agronomic practices, could meet 54–82% of the N reductions targets (28–43 kt N reduction) and 38–64% P reduction targets (4–6.6 kt P reduction), depending on scenario. SANBALTS output showed that even partial fulfillment of nutrient reduction targets could have ameliorating effects on eutrophication conditions. Meeting BSAP targets will require addressing additional sources, such as sewage. A common approach to apportioning sources to external nutrients loads could enable further assessment of the feasibility of eutrophication management targets.
Ambio - In the original published article, the sentence “Nevertheless, semi-natural forest remnants continue to be harvested and fragmented (Svensson et al. 2018; Jonsson et al. 2019), and... 相似文献
Volatile sulfur compounds (VSCs) in biogas originating from a biogas production plant and from a municipal sewage water treatment plant were identified. Samples were taken at various stages of the biogas-producing process, including upgrading the gas to vehicle-fuel quality. Solid-phase microextraction was used for preconcentration of the VSCs, which were subsequently analyzed using gas chromatography in combination with mass spectrometry. Other volatile organic compounds present also were identified. The most commonly occurring VSCs in the biogas were hydrogen sulfide, carbonyl sulfide, methanethiol, dimethyl sulfide, and dimethyl disulfide, and hydrogen sulfide was not always the most abundant sulfur (S) compound. Besides VSCs, oxygenated organic compounds were commonly present (e.g., ketones, alcohols, and esters). The effect of adding iron chloride to the biogas reactor on the occurrence of VSCs also was investigated. It was found that additions of 500-g/m3 substrate gave an optimal removal of VSCs. Also, the use of a prefermentation step could reduce the amount of VSCs formed in the biogas process. Moreover, in the carbon dioxide scrubber used for upgrading the gas, VSCs were removed efficiently, leaving traces (ppbv levels). The scrubber also removed other organic compounds. 相似文献
Nitrogen (N) availability plays multiple roles in the boreal landscape, as a limiting nutrient to forest growth, determinant of terrestrial biodiversity, and agent of eutrophication in aquatic ecosystems. We review existing research on forest N dynamics in northern landscapes and address the effects of management and environmental change on internal cycling and export. Current research foci include resolving the nutritional importance of different N forms to trees and establishing how tree–mycorrhizal relationships influence N limitation. In addition, understanding how forest responses to external N inputs are mediated by above- and belowground ecosystem compartments remains an important challenge. Finally, forestry generates a mosaic of successional patches in managed forest landscapes, with differing levels of N input, biological demand, and hydrological loss. The balance among these processes influences the temporal patterns of stream water chemistry and the long-term viability of forest growth. Ultimately, managing forests to keep pace with increasing demands for biomass production, while minimizing environmental degradation, will require multi-scale and interdisciplinary perspectives on landscape N dynamics. 相似文献
Ambio - The choice of tree species used in production forests matters for biodiversity and ecosystem services. In Sweden, damage to young production forests by large browsing herbivores is helping... 相似文献
Costs and benefits associated with matings and the effects of mating frequency on fitness commonly differ between the sexes. As a result, outcrossing simultaneous hermaphrodites may prefer to copulate in the more rewarding sex role, generating conflicts over sperm donation and sperm receipt between mates. Because recent sex role preference models remain controversial, we contrast here some of their assumptions and predictions in the sea slug Chelidonura sandrana. For this hermaphrodite with sperm storage and internal fertilisation, risk-averse models assume that fitness pay-offs are constantly higher in the female than in the male function in any single mating. Moreover, excluding mutual partner assessment, these models predict male mating behaviour to be independent of receiver traits. The competing gender ratio hypothesis assumes that relative fitness pay-offs, and thus the preferred mating roles, vary and may reverse between matings and predicts that ejaculation strategies co-vary with receiver quality. We found that field mating rates of C. sandrana substantially exceeded what is required to maintain female fertility and fecundity, indicating large variation in direct female benefits between matings. We further demonstrate that male copulation duration adaptively increased with partner body size (i.e. fecundity) but decreased with recent partner promiscuity. These findings are compatible with the gender ratio hypothesis but contradict risk-averse models. 相似文献
We examined multiple mate choice criteria in Cophixalus ornatus, a terrestrial breeding, microhylid frog. Mate choice consisted of three stages: mate attraction (male calling), courtship
(male behavior between the call site and the nest), and nest site selection by the female. For male C. ornatus, the possession of a call with low dominant frequency relative to calling neighbors increased the probability that they would
attract females. Dominant frequency was negatively correlated with age independent of male mass and snout vent length. When
escorting the female from the call site to their nest, males traveled along more convoluted paths than when returning to the
nest alone. The convolution of the path was, therefore, considered an aspect of courtship. Females released eggs into nests
with structural characteristics typical of nests constructed by older males. Thus, females increased their chances of locating
an acceptable nest by preferentially approaching males with lower dominant frequencies. This study is the first to demonstrate
that age, independent of mass or snout-vent length, can influence call characteristics in anurans, and it is also the first
to demonstrate the importance of male age to female mate choice in an amphibian. 相似文献
Over recent decades, public participation in technology assessment has spread internationally as an attempt to overcome or
prevent societal conflicts over controversial technologies. One outcome of this new surge in public consultation initiatives
has been the increased use of participatory consensus conferences in a number of countries. Existing evaluations of consensus
conferences tend to focus on the modes of organization, as well as the outcomes, both procedural and substantial, of the conferences
they examine. Such evaluations seem to rest on the assumption that this type of procedure has universally agreed goals and
meanings, and that therefore consensus conferences can readily be interpreted and applied across national boundaries. This
article challenges this approach to consensus conferences. The core of the article is a study of national differences in ideas
about what constitutes legitimate goals for participatory arrangements. The study looks at three consensus conferences on
GMOs, which took place in France, Norway, and Denmark. Drawing on this study, the article discusses the ways in which interpretations
of the concept of participation; the value attributed to lay knowledge vs. technical expertise; as well as ideas about the
role of the layperson, are all questions that prompt entirely different answers from country to country. Further, the article
analyses these national differences within a theoretical framework of notions of democratic legitimacy. 相似文献
Research and initiatives concerning green procurement have to a great extent focused on products. This article, however, explores the current practice, problems and opportunities of green procurement of construction contracts. In particular, the application of environmental criteria for contract awarding is targeted. The findings of the study indicate that both public and private clients in the Swedish construction industry take environmental issues into consideration in their procurements. The environmental preferences are often formulated as environmental requirements. However, environmental criteria in tender evaluation are less common and seldom affect the award decisions. The environmental evaluation criteria that do occur often relate to the contractors' capabilities of managing the environmental work in the project. 相似文献