SummaryWe conducted the most extensive meta-analysis of plant and animal responses to elevated CO 2 to date. We analysed > 5000 data points extracted from 270 papers published between 1979 and 2009. We examined the changes in 19 animal response variables to the main effect of elevated CO 2 . We found strong evidence for significant variation among arthropod orders and feeding guilds, including interactions in the direction of response. We also examined the main effects of elevated CO 2 on: six plant growth and allocation responses, seven primary metabolite responses, eight secondary metabolite responses, and four physical defence responses. We examined these response variable changes under two-way and three-way interactions between CO 2 and: soil nitrogen, ambient temperature, drought, light availability, photosynthetic pathway, reproductive system, plant growth rate, plant growth form, tissue type, and nitrogen fixation. In general we found smaller effect sizes for many response variables than have been previously reported. We also found that many of the oft-reported main effects of CO 2 obscure the presence of significant two-and three-way interactions, which may help better explain the relationships between the response variables and elevated CO 2 .

The spotted-wing drosophila (Drosophila suzukii Matsumura) is an invasive species of Asian origin that is now widely distributed in North America and Europe. Because of the female's serrated ovipositor, eggs are laid in preharvest fruit, causing large economic losses in cultivated berries and stone fruit. Modeling D. suzukii population dynamics and potential distribution will require information on its thermal tolerance. Large summer populations have been found in regions with severe winter conditions, though little is known about responses to prolonged low-temperature exposure. We used controlled chambers to examine D. suzukii fecundity, development rate, and mortality across a range of temperatures encompassing the upper and lower thresholds (5-35 • C). Optimal temperatures (T opt ) were found to be 28.2 • C for the development of the egg-to-adult stage, and 22.9 • C for reproductive output. No adult eclosion occurred below 8.1 • C (T lower ) or above 30.9 • C (T upper ). We also investigated survival outcomes following prolonged (42-d) low-temperature exposure to a simulated cold winter (−5, −3, −1, 1, 3, and 5 • C). Adult survival was dependent on temperature, with a mean LT 50 of 4.9 • C. There were no effects of sex, mating status, geographic strain, and photoperiod preexposure on overwintering survival. Thirty-eight percent of females that were mated prior, but not after, prolonged low-temperature exposure produced viable offspring, suggesting that this species may undergo sperm storage. This study provides data on the thermal tolerances of D. suzukii, which can be used for models of D. suzukii population dynamics, degree-day, and distribution models.

a b s t r a c tThe leatherback, Dermochelys coriacea, is a large sea turtle that feeds primarily on jellyfish. Floating plastic garbage could be mistaken for such prey. Autopsy records of 408 leatherback turtles, spanning 123 years , were studied for the presence or absence of plastic in the GI tract. Plastic was reported in 34% of these cases. If only cases from our first report (1968) of plastic were considered, the figure was 37%. Blockage of the gut by plastic was mentioned in some accounts. These findings are discussed in the context of removal of top predators from poorly understood food chains.

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Summary1. Cool-season grasses can be simultaneously infected by foliar fungal endophytes and colonised by mycorrhizal fungi, the integrated functions of which are strong predictors of plant fitness within grassland ecosystems. Evidence has been presented previously that infection of grass species with foliar endophytes can negatively affect mycorrhizal colonisation. Here, we tested the hypothesis that mycorrhizal colonisation in turn adversely affects Neotyphodium endophyte concentrations and that the competitive interaction between the two endosymbionts is affected by resource supply. 2. Specifically, we report how competition between Glomus (G. mosseae -GM, G. intraradices -GI) mycorrhizal fungi and N. lolii (common strain (CS) and AR1) foliar endophytic strains is affected by P supply and water-soluble carbohydrate (WSC) content in two Lolium perenne (perennial ryegrass) cultivars: a high sugar grass, AberDart, and a conventional (control) grass, Fennema. 3. The presence of Glomus mycorrhizae reduced the concentrations of endophytes and alkaloids in leaf blades and pseudostems. The reduction depended on P supply, ryegrass cultivar (notably WSC content) and endophyte strain. Conversely, foliar endophyte infection reduced mycorrhizal colonisation rates and concentrations in the roots of the control cultivar Fennema, although not in the high sugar cultivar, AberDart. 4. Neither GM nor N. lolii infection had an effect per se on the yield of root or blade compared with mycorrhiza-free (M-) and endophyte-free (E-) plants, respectively; though, yield of roots and blades was reduced by GI infection and at low P. 5. Competitive interactions between ecologically widespread foliar endophytes (valuable for plant protection) and mycorrhizal endosymbionts (valuable for P acquisition) as seen in this study are of critical importance especially in areas of high pest prevalence and low P availability. Our work stresses the need for elucidating the physiological ⁄ metabolic basis for such interactions between endosymbionts to understand how these processes contribute to plant performance and fitness in grassland ecosystems.

Atmospheric CO2 is expected to increase to between 550 ppm and 1000 ppm in the next century. CO2-induced changes in plant physiology can have ecosystem-wide implications and may alter plant-plant, plant-herbivore and plant-symbiont interactions. We examined the effects of three concentrations of CO2 (390, 800 and 1000 ppm) and two concentrations of nitrogen fertilizer (0.004 g N/week versus 0.2 g N/week) on the physiological response of Neotyphodium fungal endophyte-infected and uninfected tall fescue plants. We used quantitative PCR to estimate the concentration of endophyte under altered CO2 and N conditions. We found that elevated CO2 increased the concentration of water-soluble carbohydrates and decreased the concentration of plant total amino acids in plants. Fungal-derived alkaloids decreased in response to elevated CO2 and increased in response to nitrogen fertilization. Endophyte concentration (expressed as the number of copies of an endophyte-specific gene per total genomic DNA) increased under elevated CO2 and nitrogen fertilization. The correlation between endophyte concentration and alkaloid production observed at ambient conditions was not observed under elevated CO2. These results suggest that nutrient exchange dynamics important for maintaining the symbiotic relationship between fungal endophytes and their grass hosts may be altered by changes in environmental variables such as CO2 and nitrogen fertilization.

The Epichloë fungal endophytes that inhabit grasses have potentially large-scale consequences for macro-and micro-organisms and food chains in agriculture. Over 40 years of study on the benefits of symbiotic Epichloë fungal endophytes for host grasses, investigations have focused on the major agricultural species, tall fescue and perennial ryegrass. However, many other grass species remain to be evaluated for the effects of Epichloë endophytes. Animal toxicity due to accumulation of nitrogenous compounds, e.g. endophyte-dervived alkaloids, particularly in areas and periods under abiotic stress, still prevent widespread application of endophyte-infected grasses in agroecosystems.Here we review Epichloë endophyte-ecosystem relationships. The major points are: (1) Epichloë endophytes protect their host plants from vertebrate and invertebrate herbivory and allow plants to persist under water shortage, salinity, low light, mineral deficiencies and metal toxicity. Data suggests that the concentration of endophyte-derived anti-herbviore compounds increases with rising temperatures. This trend thus suggests that the strength of mutualistic interactions may increase in future climates with possible consequences for animal toxicity. (2) The benefits of endophyte infection for the host grass are context-dependent, varying with environmental conditions, grass species and cultivar, and are also highly influenced

1 Rising atmospheric CO 2 has been shown to alter plant nitrogen metabolism, growth and secondary chemistry. We hypothesized that altered aphid performance under elevated CO 2 is linked to phloem nitrogen chemistry. 2 Rhopalosiphum padi performance on endophyte-infected or uninfected tall fescue was examined under three levels of CO 2 (ambient, 800 and 1000 p.p.m.) and high and low nitrogen fertilization. Ethylenediaminetetracetic acid-facilitated exudation was used to sample phloem sap, followed by quantification of relative amino acid concentrations using reverse-phase high-performance liquid chromatography. 3 Aphid abundance was reduced at 800 p.p.m. relative to ambient CO 2 but returned to baseline at 1000 p.p.m. The density of aphids was reduced in both the elevated CO 2 treatments. Aphids were unsuccessful at colonizing endophyte-infected plants, possibly as a result of the presence of loline alkaloids. 4 Multivariate analysis showed that certain groups of phloem amino acids were altered by nitrogen fertilization and CO 2 . We found that four amino acids (valine, arginine, glutamine and aspartate) were correlated with aphid performance. These findings partially explained the effect of plant nitrogen fertilization and elevated CO 2 on aphids. 5 The present study represents a first step toward providing a mechanistic explanation of the aphid performance changes that may result from rising atmospheric CO 2 .