Response of community composition and biomass of submerged macrophytes to variation in underwater light, wind and trophic status in a large eutrophic shallow lake

Light climate is of key importance for the growth, community composition of submerged macrophytes in lakes and, they, in turn, are affected by lake depth and the degree of eutrophication. To test the relationships between submerged macrophyte presence and the ratio of Secchi disk depth (SDD) to water depth, i.e. SDD/depth, nutrients and wind, we conducted an extensive sampling campaign in a macrophyte-dominated area of the eastern region (n = 36) in 2016 in Lake Taihu, China, and combined the data gathered with results from extensive physico-chemical monitoring data from the entire lake. We confirmed that SDD/Depth is the primary factor controlling the community composition of macrophytes and showed that plant abundance increased with increasing SDD/Depth ratio (p < 0.01), but that only SDD/Depth > 0.4 ensured growth of submerged macrophytes. Total phosphorus and total nitrogen also influenced the growth and community composition of macrophytes (p < 0.01), while Chla was an indirectly affecting factor by reducing underwater light penetration. Wave height significantly influenced plant abundance (p < 0.01), whereas it had little effect on the biomass (p > 0.05). The key to restore the macrophyte beds in the lake is to reduce the nutrient loading. A decrease of the water level may contribute as well in the shallow bays but will not bring plants back in the main part of the lake. As the tolerance of shade and nutrients varied among the species studied, this should be taken into account in the restoration of lakes by addition of plants.     

Using Public–Private Interplay to Climate-Proof Urban Planning? Critical Lessons from Developing a new Housing District in Karlstad,Sweden

While strengthening public–private interplay is expected to improve the climate profile of urban planning in terms of mitigation and adaptation, less is known about the practice of such new interactive modes of governing. The paper critically examines the role, benefits and limitations of extended public–private interplay in developing a new housing district in Sweden. The developer dialogue between municipal officials and property developers confirms mutual interests, shared understandings and the added value of interacting. However, the closer the dialogue comes to settling agreements, the more difficult it gets for municipal officials to steer the process and its outcomes in favor of climate proofing. Complications with adapting to the new interactive setting means that municipal officials balance between acting as facilitators and/or regulators and property developers between acting as partners, competitors and/or defenders. Refining steering-strategies for sustaining commitments and securing formal agreements are pertinent for using public–private interplay to climate-proof urban planning.     

Managing climate change vulnerabilities: formal institutions and knowledge use as determinants of adaptive capacity at the local level in Sweden

Though managing vulnerabilities posed by climate change calls for effective strategies and measures, its challenges have hitherto not been fully understood. In Sweden, municipalities have recently started incorporating vulnerability management into their political and administrative agendas. This study discusses such experiences and explores how institutional determinants may influence adaptive capacity within a local case study area, to illustrate emerging challenges and opportunities for Swedish municipalities in managing climate vulnerabilities. Specifically, formal institutional structure and the use of knowledge are analysed, concluding that vulnerability management often is focused on technical and reactive fixes, due to limited co-operation between local sector organisations, lack of local co-ordination, and an absence of methods and traditions to build institutional knowledge. Even so, opportunities, such as a high capacity to examine risks to technical systems and important establishments which in turn facilitates protection of technical infrastructure exposed to climate variability and change, also exist.     

Collaborative Modeling for Decision Support in Water Resources: Principles and Best Practices

Collaborative Modeling for Decision Support integrates collaborative modeling with participatory processes to inform natural resources decisions. Practitioners and advocates claim that the approach will lead to better water management, balancing interests more effectively and reducing the likelihood of costly legal delays. These claims are easy to make, but the benefits will only be realized if the process is conducted effectively. To provide guidance for how to conduct an effective collaborative modeling process, a task committee cosponsored by the Environmental Water Resources Institute (EWRI) of the American Society of Civil Engineers and by the U.S. Army Corps of Engineers' Institute for Water Resources developed a set of Principles and Best Practices for anyone who might convene or conduct collaborative modeling processes. The guidance is intended for both conflict resolution professionals and modelers, and our goal is to integrate these two fields in a way that will improve water resources planning and decision making. Here, the set of eight principles is presented along with a selection of associated best practices, illustrated by two different case examples. The complete document is available at: http://www.computeraideddisputeresolution.us/bestpractices/ .     

Antimony leaching in plastics from waste electrical and electronic equipment (WEEE) with various acids and gamma irradiation

There has been a recent interest in antimony since the availability in readily mined areas is decreasing compared to the amounts used. It is important in many applications such as flame retardants and in the production of polyester, which can trigger an investigation of the leachability of antimony from plastics using different acids. In this paper, different types of acids are tested for their ability to leach antimony from a discarded computer housing, made of poly(acrylonitrile butadiene styrene), which is a common plastic type used in electrical and electronic equipment. The acid solutions included sodium hydrogen tartrate (0.5 M) dissolved in either dimethyl sulfoxide or water (at ca. 23 °C and heated to ca. 105 °C). The metal content after leaching was determined by inductively coupled plasma optical emission spectroscopy. The most efficient leaching medium was the heated solution of sodium hydrogen tartrate in dimethyl sulfoxide, which leached almost half of the antimony from the poly(acrylonitrile butadiene styrene). Gamma irradiation, which is proposed to improve the mechanical properties in plastics, was used here to investigate the influence of antimony leaching ability. No significant change in the amount of leached antimony could be observed.     

Is Indonesian peatland loss a cautionary tale for Peru? A two-country comparison of the magnitude and causes of tropical peatland degradation

Mitigation and Adaptation Strategies for Global Change - Indonesia and Peru harbor some of the largest lowland tropical peatland areas. Indonesian peatlands are subject to much greater...     

Disentangling the drivers of reduced long-distance seed dispersal by birds in an experimentally fragmented landscape

Seed dispersal is a crucial component of plant population dynamics. Human landscape modifications, such as habitat destruction and fragmentation, can alter the abundance of fruiting plants and animal dispersers, foraging rates, vector movement, and the composition of the disperser community, all of which can singly or in concert affect seed dispersal. Here, we quantify and tease apart the effects of landscape configuration, namely, fragmentation of primary forest and the composition of the surrounding forest matrix, on individual components of seed dispersal of Heliconia acuminata, an Amazonian understory herb. First we identified the effects of landscape configuration on the abundance of fruiting plants and six bird disperser species. Although highly variable in space and time, densities of fruiting plants were similar in continuous forest and fragments. However, the two largest-bodied avian dispersers were less common or absent in small fragments. Second, we determined whether fragmentation affected foraging rates. Fruit removal rates were similar and very high across the landscape, suggesting that Heliconia fruits are a key resource for small frugivores in this landscape. Third, we used radiotelemetry and statistical models to quantify how landscape configuration influences vector movement patterns. Bird dispersers flew farther and faster, and perched longer in primary relative to secondary forests. One species also altered its movement direction in response to habitat boundaries between primary and secondary forests. Finally, we parameterized a simulation model linking data on fruit density and disperser abundance and behavior with empirical estimates of seed retention times to generate seed dispersal patterns in two hypothetical landscapes. Despite clear changes in bird movement in response to landscape configuration, our simulations demonstrate that these differences had negligible effects on dispersal distances. However, small fragments had reduced densities of Turdus albicollis, the largest-bodied disperser and the only one to both regurgitate and defecate seeds. This change in Turdus abundance acted together with lower numbers of fruiting plants in small fragments to decrease the probability of long-distance dispersal events from small patches. These findings emphasize the importance of foraging style for seed dispersal and highlight the primacy of habitat size relative to spatial configuration in preserving biotic interactions.     

Synthesizing units as modeling tool for photosynthesizing organisms with photoinhibition and nutrient limitation

This paper develops a mechanistic ecological model of photosynthesis based on a synthesizing unit with terms for nutrient limitation and wavelength dependent photoinhibition. The model satisfactorily fits standard P-I data with a clear inhibitory impact of excess radiation. Furthermore, the model satisfactorily discriminates between the inhibitory impact of PAR, UVA and UVB. The inhibitory potential of UVA is less than 1 order of magnitude higher than that of PAR, whereas that of UVB is about 2 orders of magnitude higher than PAR. The model can also satisfactorily describe photosynthesis rates as a function of both PAR and environmental nitrate concentrations. At relatively low nutrient levels, the model produces a curve that ascends quickly to a near saturation level; this is a trend often observed in experimental data and described well by a hyperbolic tangent. The results in this paper suggest that nutrient limitation is an overlooked factor in the experimental design for obtaining P-I data. The SU model in this paper is the simplest possible model of photosynthesis with nutrient limitation and photoinhibition that is consistent with Dynamic Energy Budget theory, in which the model can be embedded to obtain dynamic properties.     

Place-based management at different spatial scales

Place-based management is any management action having implications for a specified area. Place-based management is seen as a key component to practical implementation of ecosystem approach to management, with marine spatial planning (MSP) being the currently most promoted approach. In the present paper we address the challenges of place-based management at local, regional and global (oceanic) spatial scales using case studies from the Northeast Atlantic with examples from Norway. Both ecological, governance and management complexity increases with increasing geographic scale, with associated increases in uncertainty and thus increasing need for managing under the precautionary approach. A process where (ecologically) valuable and vulnerable areas are defined early on is essential to successful place-based management under the ecosystem approach. Integrating across sectors and achieving necessary cooperation between involved institutions and stakeholders is also necessary.     

Validation of the inhalable dust algorithm of the Advanced REACH Tool using a dataset from the pharmaceutical industry

As it is often difficult to obtain sufficient numbers of measurements to adequately characterise exposure levels, occupational exposure models may be useful tools in the exposure assessment process. This study aims to refine and validate the inhalable dust algorithm of the Advanced REACH Tool (ART) to predict airborne exposure of workers in the pharmaceutical industry. The ART was refined to reflect pharmaceutical situations. Largely task based workplace exposure data (n = 192) were collated from a multinational pharmaceutical company with exposure levels ranging from 5 × 10(-5) to 12 mg m(-3). Bias, relative bias and uncertainty around geometric mean exposure estimates were calculated for 16 exposure scenarios. For 12 of the 16 scenarios the ART geometric mean exposure estimates were lower than measured exposure levels with on average, a one-third underestimation of exposure (relative bias -32%). For 75% of the scenarios the exposure estimates were, within the 90% uncertainty factor of 4.4, as reported for the original calibration study, which may indicate more uncertainty in the ART estimates in this industry. While the uncertainty was higher than expected this is likely due to the limited number of measurements per scenario, which were largely derived from single premises.