Explore the vast range of titles available.

Long-chain polyunsaturated fatty acids (LC-PUFA) are critical for the health of aquatic and terrestrial organisms; therefore, understanding the production, distribution, and abundance of these compounds is imperative. Although the dynamics of LC-PUFA production and distribution in aquatic environments has been well documented, a systematic and comprehensive comparison to LC-PUFA in terrestrial environments has not been rigorously investigated. Here we use a data synthesis approach to compare and contrast fatty acid profiles of 369 aquatic and terrestrial organisms. Habitat and trophic level were interacting factors that determined the proportion of individual omega-3 (n-3) or omega-6 (n-6) PUFA in aquatic and terrestrial organisms. Higher total n-3 content compared with n-6 PUFA and a strong prevalence of the n-3 PUFA eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) characterized aquatic versus terrestrial organisms. Conversely, terrestrial organisms had higher linoleic acid (LNA) and alpha-linolenic acid (ALA) contents than aquatic organisms; however, the ratio of ALA:LNA was higher in aquatic organisms. The EPA + DHA content was higher in aquatic animals than terrestrial organisms, and increased from algae to invertebrates to vertebrates in the aquatic environment. An analysis of covariance (ANCOVA) revealed that fatty acid composition was highly dependent on the interaction between habitat and trophic level. We conclude that freshwater ecosystems provide an essential service through the production of n-3 LC-PUFA that are required to maintain the health of terrestrial organisms including humans.

Spoilage fungi are ubiquitous contaminants of cereals, pre- and post-harvest. These fungi can produce a wide range of secondary metabolites under ecological conditions which are conducive for growth. However, some of these secondary metabolites are toxic and have a significant impact if they enter the production and animal food chains. Prevention of mycotoxin contamination of feed and food raw materials is now considered more important than subsequent cure. The key ecological determinants pre- and post-harvest are water availability and temperature (climate). Accurate information is therefore needed on the impact of an association between these key factors, and it is necessary to understand which are marginal and which critical for germination and toxin production. There have only been a few studies where attempts have been made to integrate the available information on these factors in relation to different raw materials for feed and food processing, especially cereals. This review will examine the available information on the main climatic factors, i.e., water availability and temperature affecting mycotoxin production such as, aflatoxins, ochratoxins, fumonisins, zearalenone, deoxynivalenol and citrinin. This information is crucial for accurately focusing and monitoring key critical control points in the feed and food chain to optimise prevention strategies.

Predators of herbivorous animals can affect plant populations by altering herbivore density, behavior, or both. To test whether the indirect effect of predators on plants arises from density or behavioral responses in a herbivore population, we experimentally examined the dynamics of terrestrial food chains comprised of old field plants, leaf-chewing grasshoppers, and spider predators in Northeast Connecticut. To separate the effects of predators on herbivore density from the effects on herbivore behavior, we created two classes of spiders: risk spiders that had their feeding mouth parts glued to render them incapable of killing prey and predator spiders that remained unmanipulated. We found that the effect of predators on plants resulted from predator-induced changes in herbivore behavior (shifts in activity time and diet selection) rather than from predator-induced changes in grasshopper density. Neither predator nor risk spiders had a significant effect on grasshopper density relative to a control. This demonstrates that the behavioral response of prey to predators can have a strong impact on the dynamics of terrestrial food chains. The results make a compelling case to examine behavioral as well as density effects in theoretical and empirical research on food chain dynamics

The generality of the trophic cascade has been an intensely debated topic among ecologists. We conducted a meta-analysis of 54 separate enclosure and pond experiments that measured the response of the zooplankton and phytoplankton to zooplanktivorous fish treatments. These results provide unequivocal support for the trophic cascade hypothesis in freshwater food webs. Zooplanktivorous fish treatments resulted in reduced zooplankton biomass and increased phytoplankton biomass. The trophic cascade was weakly dampened at the level of the phytoplankton. However, the response of the phytoplankton to the trophic cascade was highly skewed, with very strong responses in slightly more than one-third of the cases and weak responses in the others.

This book bridges the gap between the energetic and species approaches to studying food webs, addressing many important topics in ecology. Species, matter, and energy are common features of all ecological systems. Through the lens of complex adaptive systems thinking, the authors explore how the inextricable relationship between species, matter, and energy can explain how systems are structured, and how they persist in real and model systems. Food webs are viewed as open and dynamic systems. The central theme of the book is that the basis of ecosystem persistence and stability rests on the interplay between the rates of input of energy into the system from living and dead sources, and the patterns in utilization of energy which result from the trophic interactions among species within the system. To develop this theme, the authors integrate the latest work on community dynamics, ecosystem energetics, and stability. In so doing, they present a unified ecology that dispels the categorization of the field into the separate subdisciplines of population, community, and ecosystem ecology.

One-third of all food produced in the world is lost or wasted from farm to fork, according to estimates calculated by FAO (2011). This wastage not only has an enormous negative impact on the global economy and food availability, it also has major environmental impacts. The direct economic cost of food wastage of agricultural products (excluding fish and seafood), based on producer prices only, is about 750 billion USD, equivalent to the GDP of Switzerland. The aim of the Toolkit is to showcase concrete examples of good practices for food loss and waste reduction, while pointing to information sources, guidelines and pledges favoring food wastage reduction. The inspirational examples featured throughout this Toolkit demonstrate that everyone, from individual households and producers, through governments, to large food industries, can make choices that will ultimately lead to sustainable consumption and production patterns, and thus, a better world for all.

and what are the main sources of these impacts, in terms of regions, commodities, and phases of the food supply chain in order to identify environmental hotspots related to food wastage This FAO study provides a global account of the environmental footprint of food wastage (i.e. both food loss and food waste) along the food supply chain, focusing on impacts on climate, water, land and biodiversity. A model has been developed to answer two key questions: what is the magnitude of food wastage impacts on the environment

A soil community food web model was used to improve the understanding of what factors govern the mineralisation of nutrients and carbon and the decay of dead organic matter. The model derives the rates of C and N mineralisation by organisms by splitting their uptake rate of food resources into a rate at which faeces or prey remains are added to detritus, a rate at which elements are incorporated into biomass, and a rate at which elements are released by organisms as inorganic compounds. The functioning of soil organisms in the mineralisation of C and N was modelled in the soil horizon of a Scots pine forest. The organic horizon was divided into three distinct layers, representing successive stages of decay, i.e. litter, fragmented litter, and humus. Each of the layers had a different, quantitative, biota composition. For each layer the annual C and N mineralisation rates were simulated and compared to observed C and N mineralisation rates from organic matter in stratified litterbags. Simulated C and N mineralisation was relatively close to measured losses of C and N, but the fit was not perfect. Discrepancies between the observed and predicted mineralisation rates are discussed in terms of variation in model parameter values of those organisms that showed the highest contribution to mineralisation rates. The measured, and by the model predicted, significant decrease in mineralisation rates down the profile was not explained by the biomass of the primary decomposers and only partly by the total food web biomass. Modelling results indicated that indirect effects of soil fauna, due to trophic interactions with their resources, are an important explanatory factor. In addition, the analyses suggest that community food web structure is an important factor in the regulation of nutrient mineralisation. The model provided the means to evaluate the contribution of functionally defined groups of organisms, structured in a detrital food web, to losses of C and N from successive decay stages.

Investigation of tree growth in Isle Royale National Park in Michigan revealed the influence of herbivores and carnivores on plants in an intimately linked food chain. Plant growth rates were regulated by cycles in animal density and responded to annual changes in primary productivity only when released from herbivory by wolf predation. Isle Royale's dendrochronology complements a rich literature on food chain control in aquatic systems, which often supports a trophic cascade model. This study provides evidence of top-down control in a forested ecosystem

Previously we reported that a significant level of domoic acid, a causative toxin for amnesic shellfish poisoning, was detected in bivalves belonging to a genus Spondylus from various tropical Asian countries. These findings indicate that causative plankton species for domoic acid widely distribute in these areas. In the present study, we monitored seasonal change of domoic acid level of Spondylus versicolor in association with that of plankton samples in Nha Phu Bay, Khanh Hoa, Vietnam from December 2004 to October 2005. The toxicity of S. versicolor showed distinct seasonal variation. During the period when domoic acid level of S. versicolor was increasing, a significant level of domoic acid was detected in the plankton samples, showing the correlation between these two parameters. These findings show that plankton causative for domoic acid occurred in the bay, and S. versicolor accumulate domoic acid during a bloom of the toxic plankton by food web transfer.