Biomass-Cover Relationship for Eelgrass Meadows

Eelgrass meadows play key roles in coastal ecosystems, and the extent of the standing biomass is focal to address ecosystem functioning. Eelgrass cover is commonly assessed in marine monitoring programs while biomass sampling is destructive and expensive. Therefore, we have proposed a functional relationship that translates eelgrass cover into aboveground biomass using site-specific information on Secchi depth or light attenuation. The relationship was estimated by non-linear regression on 791 combined observations of eelgrass cover and biomass from eight different coastal sites in Denmark. Eelgrass biomass initially increased with cover and flattened out as cover exceeded 40–50 % due to increased self-shading. Decreasing light energy with depth reduced the eelgrass biomass potential (assessed at 100 % cover), and this reduction was stronger for coastal sites with lower water transparency. Moreover, the biomass potential varied seasonally from around 110–140 g DW m^?2 in spring months to a peak of 241 g DW m^?2 in August, consistent with other seasonal studies. The model explained 56 % of the variation in log-transformed biomasses, but significant variation between coastal sites still remained, deviating between ?23 and 39 % from the mean relationship. These site-specific deviations could be due to differences in losses related to grazing, drifting algae and epiphytes, better light capture by dense canopies, as well as differences in how well light conditions within eelgrass meadows are represented by actual measurements of Secchi depth and light attenuation. The relationship can be employed to estimate eelgrass biomass of entire coastal ecosystems from observations of eelgrass cover and depth.     

Selective digestion of industrial potato wastes for efficient biomethanation: a sustainable solution for safe environmental disposal

Potato being the staple vegetable in India is widely cultivated and processed for different value additions. During processing of potato, a huge amount of waste is generated in the form of peel and meat (mash). These wastes constitute a potential feedstock for biogas generation. The present study is focused on mitigation of acidogenesis that occurs during early stages of anaerobic digestion (AD) of potato waste which eventually inhibits the process of methanogenesis. A novel strategy of selective digestion was adopted in which the leachate and solid slurry resulting from the first stage digestion were further subjected to second stage by separating the solid and liquid phases. The obtained results indicated that stepwise digestion enhanced biomethane yield with an increase in methane percent from 46.47 to 60.4 % and reduction in total COD to about 94 %. Another novel strategy adopted in this study was the use of specifically developed microbial consortia for AD of potato wastes instead of conventional inoculum for production of biogas. The obtained yield is at par with the conventional inoculums which suggests that the developed consortia could act as potential substitute. The present study paves the way for sustainable utilization of industrial potato wastes for bioenergy production by overcoming the problems associated with conventional processes.     

Suburban Food Security: Walkability and Nutritional Access in Metropolitan Detroit

This article explored the relationship between the local food environment and walkability in the socioeconomically diverse, inner-ring suburbs of metropolitan Detroit. The availability and cost differentials of food were surveyed using a modified version of the Nutrition Environment Measures Survey for Stores (NEMS–S), and a geographic information system–based method was designed to map walkability relative to licensed food retail establishments. Results showed that minority communities lack access to fresh produce and nutritionally adequate foods, which is compounded by limited mobility. By incorporating local-based economic incentives, low-income communities can better align neighborhood goals of obtaining nutritionally adequate food (and other services) with economic opportunity.     

A laboratory atlas of the 5ν1 NH3 absorption band at 6475 Å with applications to Jupiter and Saturn

The 5ν₁ absorption band of NH₃ is displayed from 6418 to 6550 Å. The total band intensity has been measured: S_B = 0.66 cm^?1m^?1amagat^?1. Line intensities and self-broadening coefficients have been measured for some of the prominent lines. Our line intensities are in good agreement with those of Rank et al. (1966), but are about 2 times greater than those of Mason (1970). The spectrum displayed was obtained photoelectrically at a pressure of 0.061 atm, and shows many more lines than the spectrum obtained by McBride and Nicholls (1972a) at a pressure of 0.39 atm. Therefore, our new measurements can provide the basis for making a more complete rotational analysis than those of McBride and Nicholls (1972a).Since the total band absorption has previously been measured by others on moderate resolution photoelectric scans of the spectra of Jupiter and Saturn, we can use the band intensity to derive the NH₃ abundance in the atmospheres of these two planets. The NH₃ abundances in a single vertical path obtained by this method are about 10m amagat for Jupiter and 2m amagat for Saturn. These results are in agreement with previous results obtained from higher resolution photographic spectra.     

Habitat Structure,Disturbance, and Equilibrium in Crustacean Communities*

Abstract. Using data from studies on alga-dwelling harpacticoid copepods from New Zealand and Britain and shallow water decapods from a variety of habitats in the Pacific and Caribbean, an analysis is made of the contribution of physical and biotic habitat structures to the generation and maintenance of crustacean species richness. The relation between the number of species and the complexity of the habitat is, in equilibrium communities, positive and essentially linear. Accordingly, Gray's (1979) and Stenseth's (1979) theoretical predictions are endorsed whereby species-abundance curves are, at equilibrium, expected to follow a log-normal distribution, whereas departures from the log-normal are anticipated in disturbed environments. Such departures reflect either increased dominance or inequalities in the species-abundance hierarchy. Because of their adaptable life-history traits, certain opportunist species are identified as those contributing most to departure points. The impact on community equilibrium of natural disturbance processes such as turbidity, exposure, and substratum transience is assessed.     

Absolute pollen productivity and pollen–vegetation relationships in northern Finland

Pollen productivity is one of the most critical parameters for pollen–vegetation relationships, and thus for vegetation reconstruction, in either pollen percentages or pollen accumulation rates. We obtain absolute pollen productivity of three major tree types in northern Finland: pine (Pinus sylvestris), spruce (Picea abies) and birch (Betula pubescens ssp. pubescens and B. pubescens ssp. czerepanovii treated as one taxon). Long‐term monitoring records of pollen traps from 15 sites (duration: 5–23 years) and tree volume estimates within a 14 km radius of each trap were compared to estimate pollen productivity (grains m^?3 a^?1) of these trees using a regression method. The slope of the linear relationship between pollen loading and distance‐weighted plant abundance represents pollen productivity. Estimated productivities of pollen (×10⁸ grains m^?3 a^?1) for pine, spruce and birch are 128.7 (SE 31.5), 341.9 (SE 81.3) and 411.4 (SE 307.7), respectively. The birch estimate (P > 0.05) is not as good as the others and should be used with caution. Pollen productivities of pine, spruce and birch in northern Finland are, in general, comparable to those of congeneric species in other regions of Europe and Japan. Although the year‐to‐year variations are significant, our volume‐based estimates of pollen productivity for pine and spruce will be essential for quantitative reconstruction of vegetation in the region. Copyright © 2009 John Wiley & Sons, Ltd.     

Synergies and tradeoffs in how managers,scientists, and fishers value coral reef ecosystem services

Managing ecosystems in a changing environment faces the challenge of balancing diverse competing perspectives on which ecosystem services – nature's benefits – to prioritize. Consequently, we measured and compared how different stakeholders (managers, scientists and fishers) prioritize specific coral reef ecosystem services. Managers’ priorities were more aligned with scientists’ priorities but all stakeholder groups agreed that fishery, education, and habitat were high priorities. However, stakeholder groups differed in the extent to which they prioritized certain services. Fishers tended to assigned greater estimates to fishery and education, managers to culture, and scientists to coastal protection. Furthermore, using network analysis to map the interactions between stakeholders’ priorities, we found distinct synergies and trade-offs in how ecosystem services were prioritized, representing areas of agreement and conflict. In the fishers’ network, trade-offs emerged between two services, both of a higher priority, such as fishery and habitat. Conversely, in the scientists’ network, trade-offs emerged between services of a higher and lower priority, such as habitat and culture. The trade-offs and synergies that emerged in the managers’ network overlap with both fishers’ and scientists’ suggesting a potential brokering role that managers can play in balancing both priorities and conflicts. We suggest that measuring ecosystem service priorities can highlight key areas of agreement and conflict, both within and across stakeholder groups, to be addressed when communicating and prioritizing decisions.