Biotic interactions underlie ecosystem structure and function, but predicting interaction outcomes is difficult. We tested the hypothesis that biotic interaction strength increases toward the equator, using a global experiment with model caterpillars to measure predation risk. Across an 11,660-kilometer latitudinal gradient spanning six continents, we found increasing predation toward the equator, with a parallel pattern of increasing predation toward lower elevations. Patterns across both latitude and elevation were driven by arthropod predators, with no systematic trend in attack rates by birds or mammals. These matching gradients at global and regional scales suggest consistent drivers of biotic interaction strength, a finding that needs to be integrated into general theories of herbivory, community organization, and life-history evolution.

To manage biosolids in a sustainable manner, there is a need for further research in the following areas: achieving a higher degree of public understanding and acceptance for the beneficial use of biosolids, developing cost-efficient and effective thermal conversions for direct energy recovery from biosolids, advancing technology for phosphorus recovery, and selecting or breeding crops for efficient biofuel production.

This study investigates factors affecting reproduction in fish exposed to pulp and paper mill effluents by comparing effluents from countries with varying levels of documented effects. To explore the hypothesis of wood as a common source of endocrine disrupting compounds, feedstocks from each country were analyzed. Analyses included in vitro assays for androgenic activity (binding to goldfish testis androgen receptors), estrogenic activity (yeast estrogen screen), and neurotransmitter enzyme inhibition (monoamine oxidase and glutamic acid decarboxylase). Chemical analyses included conventional extractives, known androgens, and gas chromatograph index (GCI) profiles. All effluents and wood contained androgenic activity, particularly in nonpolar fractions, although known androgens were undetected. Effluents with low suspended solids, having undergone conventional biotreatment had lower androgenic activities. Estrogenic activity was only associated with Brazilian effluents and undetected in wood. All effluents and wood inhibited neurotransmitter enzymes, predominantly in polar fractions. Kraft elemental chlorine free mills were associated with the greatest neurotransmitter inhibition. Effluent and wood GCI profiles were correlated with androgenic activity and neurotransmitter enzyme inhibition. Differences in feedstock bioactivities were not reflected in effluents, implying mill factors mitigate bioactive wood components. No differences in bioactivities could be discerned on the basis of country of origin, thus we predict effluents in regions lacking monitoring would affect fish reproduction and therefore recommend implementing such programs.

The growth/survival of Aeromonas spp. and Yersinia enterocolitica on cod and trout stored in two modified atmospheres at 0 degrees, 5 degrees and 12 degrees C was compared with that on aerobically stored fish. Both organisms grew on aerobically stored fish at all three temperatures. Growth on the modified-atmosphere-stored fish was never greater and was generally markedly less than on aerobically stored fish. This reduction in growth was greater in the higher carbon dioxide-containing atmosphere and at the lower temperature(s).