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Globally, saline lakes are experiencing declining water level as a consequence of climate change, water diversions for human consumption, and management strategies that do not account for changing climate and drought conditions. Great Salt Lake (GSL) is a large saline lake in Utah, USA, and is, as most saline lakes, experiencing decreasing lake levels which may impact local carbon cycling. It is unknown how lakebed drying affects processes that control carbon sequestration and carbon emissions to the atmosphere. The goal of this research was to measure various biological processes that use, create, and transform carbon in GSL to understand the impacts of declining lake levels on carbon in this ecosystem Gross primary production (GPP) and respiration (R) are processes within the lake and lakebed sediments, performed by plants, algae, and microorganisms, that use and create oxygen and carbon for energy. Gross primary production (GPP) uses carbon dioxide to create oxygen and organic carbon, while respiration (R) uses oxygen and organic carbon to create carbon dioxide. To determine how the total consumption and production of carbon within the lake is affected by lake level decreases, GPP and R were measured in GSL in 2020 and 2021, during which time lake levels decreased more than .8 m. Measurements showed that GPP and R were very different across regions of GSL. Results showed that there was more R than GPP in both years, indicating that there was a net creation of carbon dioxide by organisms in the lake. Gross primary production and R decreased from 2020 to 2021 due to the large decrease in lake levels. Carbon dioxide emissions from exposed lakebed sediments were also measured in 2020 and showed that there were high levels of carbon dioxide released from sediments during summer months and lower levels released during winter months. Carbon dioxide emissions from the sediments were controlled by the amount of moisture in the sediments and by temperature, indicating that emissions were low in very dry or very wet sediments and lower during cold weather. This research show that there are important changes in the GSL ecosystem as lake levels decrease. Future research should investigate patterns in how organisms use, create, and transform carbon change around the lake and what this means for future changes in GSL.

Ongoing climate change can shift organism phenology in ways that vary depending on species, habitats and climate factors studied. To probe for large-scale patterns in associated phenological change, we use 70,709 observations from six decades of systematic monitoring across the former Union of Soviet Socialist Republics. Among 110 phenological events related to plants, birds, insects, amphibians and fungi, we find a mosaic of change, defying simple predictions of earlier springs, later autumns and stronger changes at higher latitudes and elevations. Site mean temperature emerged as a strong predictor of local phenology, but the magnitude and direction of change varied with trophic level and the relative timing of an event. Beyond temperature-associated variation, we uncover high variation among both sites and years, with some sites being characterized by disproportionately long seasons and others by short ones. Our findings emphasize concerns regarding ecosystem integrity and highlight the difficulty of predicting climate change outcomes., The work was financially supported by the Academy of Finland, grants 250243 (O.O.), 284601 (O.O.), 309581 (O.O.); the European Research Council, ERC Starting Grant 205905 (O.O.) and Synergy Grant 856506 – LIFEPLAN (to O.O. and T.R.); Nordic Environment Finance Corporation Grant (O.O.); Jane and Aatos Erkko Foundation Grant (O.O., T.R., M.H., L.A.); University of Helsinki HiLIFE Fellow Grant 2017–2020 (O.O.); and the Research Council of Norway through its Centres of Excellence Funding Scheme (223257) to O.O. via Centre for Biodiversity Dynamics; the Kone Foundation 44-6977 (M.D.) and 55-14839 (G.T.); a Spanish Ramon y Cajal grant RYC-2014-16263 (M.D.); the Federal Budget for the Forest Research Institute of Karelian Research Centre Russian Academy of Sciences 220-2017-0003, 0220-2017-0005 (L.V., S.S. and J.K.); the Russian Foundation for Basic Research Grant 16-08-00510 (L.K.), and the Ministry of Education and Science of the Russian Federation 0017-2019-0009 (Keldysh Institute of Applied Mathematics, Russian Academy of Sciences) (N.I., M. Shashkov).

Publisher's version (útgefin grein), Climatic impacts are especially pronounced in the Arctic, which as a region is warming twice as fast as the rest of the globe. Here, we investigate how mean climatic conditions and rates of climatic change impact parasitoid insect communities in 16 localities across the Arctic. We focus on parasitoids in a widespread habitat, Dryas heathlands, and describe parasitoid community composition in terms of larval host use (i.e., parasitoid use of herbivorous Lepidoptera vs. pollinating Diptera) and functional groups differing in their closeness of host associations (koinobionts vs. idiobionts). Of the latter, we expect idiobionts—as being less fine‐tuned to host development—to be generally less tolerant to cold temperatures, since they are confined to attacking hosts pupating and overwintering in relatively exposed locations. To further test our findings, we assess whether similar climatic variables are associated with host abundances in a 22 year time series from Northeast Greenland. We find sites which have experienced a temperature rise in summer while retaining cold winters to be dominated by parasitoids of Lepidoptera, with the reverse being true for the parasitoids of Diptera. The rate of summer temperature rise is further associated with higher levels of herbivory, suggesting higher availability of lepidopteran hosts and changes in ecosystem functioning. We also detect a matching signal over time, as higher summer temperatures, coupled with cold early winter soils, are related to high herbivory by lepidopteran larvae, and to declines in the abundance of dipteran pollinators. Collectively, our results suggest that in parts of the warming Arctic, Dryas is being simultaneously exposed to increased herbivory and reduced pollination. Our findings point to potential drastic and rapid consequences of climate change on multitrophic‐level community structure and on ecosystem functioning and highlight the value of collaborative, systematic sampling effort., We are grateful for data from the Greenland Ecosystem Monitoring Programme provided by the Department of Bioscience, Aarhus University, Denmark, in collaboration with Greenland Institute of Natural Resources, Nuuk, Greenland, and the Department of Biology, University of Copenhagen, Denmark, and data from the Greenland Ecosystem Monitoring Programme provided by Asiaq—Greenland Survey, Nuuk, Greenland. We acknowledge CSC–IT Center for Science Ltd., Espoo, Finland, for the allocation of computational resources. Rósa Erlendsdóttir kindly provided access to the sampling site in Votilækur, Iceland. We thank Marie‐Andree Giroux and Kristen Peck for their assistance in Igloolik and Marjo Kilpinen, Eija Takala and Emma Hakanen for their hard work in the laboratory. We gratefully acknowledge funding from the Academy of Finland (grants 276909, 285803 to T.R., and 276671 to M.V.K.), Nessling Foundation (grants 201700420, 201600034, 201500090 to T.K.), Jane and Aatos Erkko Foundation, Societas pro Fauna et Flora Fennica, The Danish Environmental Protection Agency (N.M.S.), French Polar Institute‐IPEV (program “Interactions 1036” to O.G. and B.S.), INTERACT, Russian Foundation for Basic Research (grant 18‐05‐60261 to A.S. and N.S.), Research Council of Norway (grant 249902/F20), the Natural Sciences and Engineering Research Council of Canada (PGS‐D award to S.K.M., CGS‐D award to A.M.S., Discovery Grant to J.B.), Churchill Northern Studies Centre (Northern Research Fund Award to A.M.S. and M.P.), Canadian Polar Commission (Northern Scientific Training Program Award to D.L.B., K.H.I.D., S.K.M., A.M.S., and M.P.), ArcticNet, Polar Continental Shelf Project, Parks Canada, Fonds Québécois de Recherche ‐ Nature et Technologies, Polar Knowledge Canada, Entomological Society of Canada, University of Guelph. The Icelandic Research Fund (Rannsóknasjóður, grant nr 152468‐051 to I.C.B.). Thanks to PhyloPic contributors Gareth Monger and Melissa Broussard.

Evaluation of long-term management regimes is important for guiding biodiversity conservation in salt marshes. However, such long-term experiments are sparse. Using a 46-year experiment in a salt marsh, we evaluated long-term effects of eight different management regimes (treatments; control, grazing, mowing, and their combinations) on the expansion of a late successional plant species (Elytrigia atherica), plant species richness and diversity, and community composition (species identities and dominance structure). Results show that E. atherica expanded strongly over time in the control treatment (without grazing or mowing) while plant species richness and diversity declined substantially. By contrast, E. atherica was greatly suppressed while plant species richness and diversity remained relatively unchanged in all other treatments except for the mowing, where species richness declined in the late season mowing treatment and plant diversity declined after 17 years in the both early and late season mowing treatment. Therefore, all management types except for the mowing were effective in conserving plant diversity. The trends for change in species identities reversed: change in species identities accumulated in the control treatment and exceeded that of other treatments 15 years after the start of the experiment. This suggests that results based on shorter-term (< 15 years) experiments may provide misleading conservation recommendations. Also, trends for change in dominance structure (taking abundance into account) were substantially different from those for species identities. Our results highlight the importance of long-term monitoring for guiding conservation management, and that monitoring should not only focus on the number of species but also community composition, to fully identify critical changes. Fil: Chen, Qingqing. University of Groningen; Países Bajos Fil: Bakker, Jan P.. University of Groningen; Países Bajos Fil: Alberti, Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Smit, Christian. University of Groningen; Países Bajos

Seit 1950 sind sowohl die Artenvielfalt von Ackerunkräutern als auch die Arthropoden und Vögel in Deutschland und darüber hinaus stark zurückgegangen. Es stellt sich die Frage, welche Rolle Ackerunkräuter bei der Unterstützung der Artenvielfalt, insbesondere von Arthropoden und Vögeln, spielen. In einer Literaturrecherche wurden 51 Ackerunkrautarten und 3 Unkrautgattungen, welche in Deutschland häufig vorkommen, auf ihre Rolle als Nahrung und Lebensraum für die Fauna untersucht. Direkte und indirekte Verbindungen zwischen Ackerunkräutern und Vögeln sowie Arthropoden wurden anhand von Daten aus der veröffentlichten Literatur gezählt. Es wurden 5180 Verbindungen zwischen den Ackerunkräutern und Arthropoden bzw. Vögeln gefunden. Die Daten weisen darauf hin, dass Ackerunkräuter nicht nur die landwirtschaftliche Erzeugung behindern, sondern auch eine Vielzahl von Ökosystemleistungen unterstützen., Since 1950, the diversity of arable weeds as well as arthropods and birds has sunk drastically in Germany and beyond. We investigate the role of arable weeds in supporting biodiversity, particularly that of arthropods and birds. In this study, 51 arable weed species and 3 weed genera that are common in Germany were reviewed for their provision of food and shelter for the fauna. Direct and indirect linkages between weeds and birds and arthropods were counted based on data from published literature. In total, 5180 linkages were found. The data indicates that weeds do much more than impede crop production, as they support a wide range of ecosystem services., Tagungsband: 30. Deutsche Arbeitsbesprechung über Fragen der Unkrautbiologie und -bekämpfung, p. 48

Cereals are very common and widespread crops in Europe. Aphids are a diverse group of herbivorous pests on cereals and one of the most important limiting factors of cereal production. Here, we present an overview of knowledge about the taxonomy, biodiversity, and ecology of cereal aphid parasitoids in Europe, an important group of natural enemies contributing to cereal aphid control. We review the knowledge obtained from the integrative taxonomy of 26 cereal aphid primary parasitoid species, including two allochthonous species (Lysiphlebus testaceipes and Trioxys sunnysidensis) and two recently described species (Lipolexis labialis and Paralipsis brachycaudi). We further review 28 hyperparasitoid species belonging to three hymenopteran superfamilies and four families (Ceraphronoidea: Megaspillidae; Chalcidoidea: Pteromalidae, Encyrtidae; Cynipoidea: Figitidae). We also compile knowledge on the presence of secondary endosymbionts in cereal aphids, as these are expected to influence the community composition and biocontrol efficiency of cereal aphid parasitoids. To study aphid–parasitoid–hyperparasitoid food webs more effectively, we present two kinds of DNA-based approach: (i) diagnostic PCR (mainly multiplex PCR), and (ii) DNA sequence-based methods. Finally, we also review the effects of landscape complexity on the different trophic levels in the food webs of cereal aphids and their associated parasitoids, as well as the impacts of agricultural practices and environmental variation., Insects, 13 (12), ISSN:2075-4450

Understanding how changes in biodiversity affects ecosystem functioning is imperative in allowing Ecosystem-Based Management (EBM), especially when addressing global change and environmental degradation. Research into the link between biodiversity and ecosystem functioning (BEF) has indeed increased considerably over the past decades. BEF research has focussed on terrestrial ecosystems and aquatic ecosystems have received considerably less attention. Due to differences in phylogenetic diversity, ecological processes and reported BEF relationships, however, it may at least be questionable whether BEF relationships are exchangeable between these ecosystems (i.e. terrestrial and aquatic). The aim of the present paper was therefore to pinpoint key areas and bottlenecks in establishing BEF relationships for aquatic ecosystems (freshwater, transitional, and marine). To this end, the available literature with special emphasis on the last 10 years was assessed to evaluate: i) reported mechanisms and shapes of aquatic BEF relationships; ii) to what extent BEF relations are interchangeable or ecosystem-specific; and iii) contemporary gaps and needs in aquatic BEF research. Based on our analysis, it may be concluded that despite considerable progress in BEF research over the past decades, several bottlenecks still need to be tackled, namely incorporating the multitude of functions supported by ecosystems, functional distinctiveness of rare species, multitrophic interactions and spatial-temporal scales, before BEF relationships can be used in ecosystem-based management. published

Global environmental changes have accelerated at an unprecedented rate in recent decades due to human activities. As a consequence, the incidence of novel abiotic conditions and biotic communities, which have been continuously emerging in the Earth system, has rapidly risen. Despite growing attention to the incidence and challenges posed by novelty in terrestrial ecosystems, novelty has not yet been quantified in marine ecosystems. Here, we measured for the rate of novelty (RoN) in abiotic conditions and community structure for three trophic levels, i.e., phytoplankton, zooplankton, and fish, in a large marine system ‐ the Baltic Sea. We measured RoN as the degree of dissimilarity relative to a specific spatial and temporal baseline, and contrasted this with the rate of change as a measure of within‐basin change over time. We found that over the past 35 years abiotic and biotic RoN showed complex dynamics varying in time and space, depending on the baseline conditions. RoN in abiotic conditions was smaller in the open Central Baltic Sea than in the Kattegat and the more enclosed Gulf of Bothnia, Gulf of Riga, and Gulf of Finland in the north. We found a similar spatial pattern for biotic assemblages, which resulted from changes in composition and stock size. We identified sea‐surface temperature and salinity as key drivers of RoN in biotic communities. Hence, future environmental changes that are expected to affect the biogeochemistry of the Baltic Sea, may favor the rise of biotic novelty. Our results highlighted the need for a deeper understanding of novelty development in marine ecosystems, including interactions between species and trophic levels, ecosystem functioning under novel abiotic conditions, and considering novelty in future management interventions., Increasing human activities have led to a faster emergence of novel abiotic conditions and biotic communities globally. We quantify the rate of novelty (RoN) in the Baltic Sea abiotic conditions, phytoplankton, zooplankton and fish communities since the 1980s. The RoN emerged in complex dynamics in abiotic and biotic components and was higher in the northern Gulfs and southern Kattegat than in the Central Baltic Sea. Changes in sea surface temperature and salinity were key drivers of biotic novelty. Novelty in marine ecosystems is emerging in complex ways. Understanding its development and drivers is needed for future management interventions.

Exotic eucalyptus (Eucalyptus spp.) has been planted widely as a fast-growing tree species in numerous tropical and subtropical countries. The expansion of eucalyptus plantations has caused several issues affecting biodiversity, such as loss of species within communities as well as alterations to ecosystem function. Previous studies of biodiversity in eucalyptus plantations have focused on single biological groups or trophic levels. How the whole biological community and trophic interactions within these plantations are affected is still poorly known. We conducted a comprehensive collection of primary producers and consumers from 42 eucalyptus plantations planted between one and 25 years ago. Primary producers, including plant materials and soil organic matter, showed significant differences in both δ13C and δ15N values. Values of δ13C and δ15N of consumers from eucalyptus plantations varied from −30.2‰ to −18.6‰ and from −1.9‰ to 8.4‰, respectively. Both δ13C and δ15N values of consumers differed among five trophic groups that we identified in eucalyptus plantations. Trophic levels in eucalyptus plantations were estimated from 1.4 to 4.4. Stable isotope evidence showed that leaves of both exotic eucalyptus, understory and adjacent sugarcane, contributed to the consumer food webs. Our results suggested food webs associated with eucalyptus plantations had complete trophic structure and depended on a suite of food sources. Nutrient inputs were typically also derived from adjacent areas indicating that maintaining diversity at the landscape level is needed to augment biodiversity and functioning of foodwebs in eucalyptus plantations.

Local environmental gradients on a catenal scale create ecological patterns from the crest to the stream of the hillslope. Bottom-up drivers interact with top-down controls to give rise to these patterns. A multidisciplinary project was conducted to study the processes that govern functioning, structure and heterogeneity on a catena in a third-order catchment in the Southern Granite Supersite in the Kruger National Park. The project included abiotic components (e.g. groundwater-surface water interactions, soil chemical and physical properties) as well as biotic components (e.g. soil microbes, small aquatic organisms in ephemeral pools, plant communities, vegetation structure and mammal diversity). Each of these components was investigated in detail along the catenal gradient and reported on in separate articles in this special issue. The drought of 2015–2016 occurred during the sampling period of the study and information on the response of vegetation and mammals to the drought were included. In this article, a synthesis of findings from the separate components or disciplines is provided to highlight the interactive functioning and ecological patterns of the catena. These findings were then used to develop a framework for multidisciplinary studies in similar environments. The framework highlights the interactive relationships between various components of the ecosystem and the importance of a multidisciplinary approach. Conservation implications: The findings of this study were used to develop a conceptual framework outlining how a range of biotic and abiotic patterns and processes interact along the catenal gradient. The framework highlights the importance of recognising these interactions in a multidisciplinary approach focused on one supersite.

The work was funded by Academy of Finland, grants 250243, 284601, 309581 (OO); the European Research Council, ERC Starting Grant 205905 (OO); Nordic Environment Finance Corporation Grant (OO); Jane and Aatos Erkko Foundation Grant (OO and TR); University of Helsinki HiLIFE Fellow Grant 2017–2020 (OO); the Kone Foundation 44-6977 (MD); Spanish Ramon y Cajal grant RYC-2014-16263 (MD); the Federal Budget for the Forest Research Institute of Karelian Research Centre Russian Academy of Sciences 220-2017-0003,0220-2017-0005 (LV, SS and JK); the Russian Foundation for Basic Research Grant 16-08-00510 (LK), and the Ministry of Education and Science of the Russian Federation 0017-2019-0009 (Keldysh Institute of Applied Mathematics, Russian Academy of Sciences) (NI, MSh)., Ovaskainen, O., Meyke, E., Lo, C., Tikhonov, G., Delgado, M.M., Roslin, T., Gurarie, E., Abadonova, M., Abduraimov, O., Adrianova, O., Akimova, T., Akkiev, M., Ananin, A., Andreeva, E., Andriychuk, N., Antipin, M., Arzamascev, K., Babina, S., Babushkin, M., Bakin, O., Barabancova, A., Basilskaja, I., Belova, N., Belyaeva, N., Bespalova, T., Bisikalova, E., Bobretsov, A., Bobrov, V., Bobrovskyi, V., Bochkareva, E., Bogdanov, G., Bolshakov, V., Bondarchuk, S., Bukharova, E., Butunina, A., Buyvolov, Y., Buyvolova, A., Bykov, Y., Chakhireva, E., Chashchina, O., Cherenkova, N., Chistjakov, S., Chuhontseva, S., Davydov, E.A., Demchenko, V., Diadicheva, E., Dobrolyubov, A., Dostoyevskaya, L., Drovnina, S., Drozdova, Z., Dubanaev, A., Dubrovsky, Y., Elsukov, S., Epova, L., Ermakova, O.S., Ermakova, O., Esengeldenova, A., Evstigneev, O., Fedchenko, I., Fedotova, V., Filatova, T., Gashev, S., Gavrilov, A., Gaydysh, I., Golovcov, D., Goncharova, N., Gorbunova, E., Gordeeva, T., Grishchenko, V., Gromyko, L., Hohryakov, V., Hritankov, A., Ignatenko, E., Igosheva, S., Ivanova, U., Ivanova, N., Kalinkin, Y., Kaygorodova, E., Kazansky, F., Kiseleva, D., Knorre, A., Kolpashikov, L., Korobov, E., Korolyova, H., Korotkikh, N., Kosenkov, G., Kossenko, S., Kotlugalyamova, E., Kozlovsky, E., Kozsheechkin, V., Kozurak, A., Kozyr, I., Krasnopevtseva, A., Kruglikov, S., Kuberskaya, O., Kudryavtsev, A., Kulebyakina, E., Kulsha, Y., Kupriyanova, M., Kurbanbagamaev, M., Kutenkov, A., Kutenkova, N., Kuyantseva, N., Kuznetsov, A., Larin, E., Lebedev, P., Litvinov, K., Luzhkova, N., Mahmudov, A., Makovkina, L., Mamontov, V., Mayorova, S., Megalinskaja, I., Meydus, A., Minin, A., Mitrofanov, O., Motruk, M., Myslenkov, A., Nasonova, N., Nemtseva, N., Nesterova, I., Nezdoliy, T., Niroda, T., Novikova, T., Panicheva, D., Pavlov, A., Pavlova, K., Petrenko, P., Podolski, S., Polikarpova, N., Polyanskaya, T., Pospelov, I., Pospelova, E., Prokhorov, I., Prokosheva, I., Puchnina, L., Putrashyk, I., Raiskaya, J., Rozhkov, Y., Rozhkova, O., Rudenko, M., Rybnikova, I., Rykova, S., Sahnevich, M., Samoylov, A., Sanko, V., Sapelnikova, I., Sazonov, S., Selyunina, Z., Shalaeva, K., Shashkov, M., Shcherbakov, A., Shevchyk, V., Shubin, S., Shujskaja, E., Sibgatullin, R., Sikkila, N., Sitnikova, E., Sivkov, A., Skok, N., Skorokhodova, S., Smirnova, E., Sokolova, G., Sopin, V., Spasovski, Y., Stepanov, S., Stratiy, V.І., Strekalovskaya, V., Sukhov, A., Suleymanova, G., Sultangareeva, L., Teleganova, V., Teplov, V., Teplova, V., Tertitsa, T., Timoshkin, V., Tirski, D., Tolmachev, A., Tomilin, A., Tselishcheva, L., Turgunov, M., Tyukh, Y., Vladimir, V., Vargot, E., Vasin, A., Vasina, A., Vekliuk, A., Vetchinnikova, L., Vinogradov, V., Volodchenkov, N., Voloshina, I., Xoliqov, T., Yablonovska-Grishchenko, E., Yakovlev, V., Yakovleva, M., Yantser, O., Yarema, Y., Zahvatov, A., Zakharov, V., Zelenetskiy, N., Zheltukhin, A., Zubina, T., Kurhinen, J.

Plankton ecosystems are complex, multi-trophic networks of biotic and abiotic interactions among physical and chemical components.Still, nutrient-phytoplankton (NP) interactions are in many cases assumed to be representative of higher trophic-level interactions in plankton ecosystems. Here, we investigate the degree to which NP interactions capture the overall dynamics of multi-trophic plankton ecosystems when accounting for realistic levels of micro-scale variability.Plankton models are typically developed based on the mean-field approach, which considers only first central moments (i.e., spatio-temporal means). Such conventional plankton models may be appropriate for meso‑ or larger-scales, but inappropriate for the highly intermittent spatial fluctuations of phytoplankton that are ubiquitous at the micro (mm) scale.Using Reynold's decomposition, the closure approach accounts for spatial variability and temporal fluctuations (higher central moments) of the phytoplankton distributions.We apply closure models of various combinations of Nutrient (N), Phytoplankton (P), and Zooplankton (Z), each with linear, hyperbolic, sigmoidal and quadratic phytoplankton mortality forms to test i) the previously advanced hypothesis ‘fluctuations enhance higher trophic level biomass in plankton models’ and ii) the suitability of nutrient-phytoplankton interactions as a proxy for higher trophic ecological processes. We find that in NP models with linear, hyperbolic and sigmoidal phytoplankton mortality (P-mortality), phytoplankton biomass (P-biomass) increases with variability, but in the NP model with quadratic P-mortality, P-biomass decreases with variability.The results are robust in the sense that similar qualitative behavior is obtained for a wide range of biologically feasible parameter sets. We investigate the characteristics of the measurable quantity coefficient of variation of phytoplankton CVp for models with different numbers of compartments.The NP models with density-independent form (linear form) and density-dependent forms (hyperbolic, sigmoidal and quadratic) for P-mortality term behave quite opposite to each other: NP models with linear P-mortality produce coefficient of variation CVp > 1 for all stable solutions while NP models with hyperbolic, sigmoidal and quadratic P-mortality forms produce CVp < 1 for all stable solutions.Depending on the mortality rate assumed, the NP model produces qualitatively different results at both micro- and macro-scales, and therefore is unable to consistently capture the true underlying dynamics of plankton ecosystems.By contrast, NPZ models behaved consistently and supported the previously advanced hypotheses, regardless of the functional form assumed for P-mortality., 公開日: 2024-03-09

Climate and land-use change are the major drivers of global biodiversity loss. Their effects are particularly acute for wide-ranging consumers, but little is known about how these factors interact to affect the abundance of large carnivores and their herbivore prey. We analyzed population densities of a primary and secondary consumer (mule deer, Odocoileus hemionus, and mountain lion, Puma concolor) across a climatic gradient in western North America by combining satellite-based maps of plant productivity with estimates of animal abundance and foraging area derived from Global Positioning Systems telemetry data (GPS). Mule deer density exhibited a positive, linear relationship with plant productivity (r2 = 0.58), varying by a factor of 18 across the climate-vegetation gradient (range: 38-697 individuals/100 km2 ). Mountain lion home range size decreased in response to increasing primary productivity and consequent changes in the abundance of their herbivore prey (range: 20-450 km2 ). This pattern resulted in a strong, positive association between plant productivity and mountain lion density (r2 = 0.67). Despite varying densities, the ratio of prey to predator remained constant across the climatic gradient (mean ± SE = 363 ± 29 mule deer/mountain lion), suggesting that the determinacy of the effect of primary productivity on consumer density was conserved across trophic levels. As droughts and longer term climate changes reduce the suitability of marginal habitats, consumer home ranges will expand in order for individuals to meet basic nutritional requirements. These changes portend decreases in the abundance of large-bodied, wide-ranging wildlife through climatically driven reductions in carrying capacity, as well as increased human-wildlife interactions stemming from anthropogenic land use and habitat fragmentation.

Many organisms adjust their reproductive phenology in response to climate change, but phenological sensitivity to temperature may vary between species. For example, resident and migratory birds have vastly different annual cycles, which can cause differential temperature sensitivity at the breeding grounds, and may affect competitive dynamics. Currently, however, adjustment to climate change in resident and migratory birds have been studied separately or at relatively small geographical scales with varying time series durations and methodologies. Here, we studied differential effects of temperature on resident and migratory birds using the mean egg laying initiation dates from 10 European nest box schemes between 1991 and 2015 that had data on at least one resident tit species and at least one migratory flycatcher species. We found that both tits and flycatchers advanced laying in response to spring warming, but resident tit populations advanced more strongly in relation to temperature increases than migratory flycatchers. These different temperature responses have already led to a divergence in laying dates between tits and flycatchers of on average 0.94 days per decade over the current study period. Interestingly, this divergence was stronger at lower latitudes where the interval between tit and flycatcher phenology is smaller and winter conditions can be considered more favorable for resident birds. This could indicate that phenological adjustment to climate change by flycatchers is increasingly hampered by competition with resident species. Indeed, we found that tit laying date had an additional effect on flycatcher laying date after controlling for temperature, and this effect was strongest in areas with the shortest interval between both species groups. Combined, our results suggest that the differential effect of climate change on species groups with overlapping breeding ecology affects the phenological interval between them, potentially affecting interspecific interactions., T.E. acknowledges the funding by the Academy of Finland (project 265859). MM and RM were financially supported by the Estonian Research Council (institutional research funding IUT number 34‐8). I.K. received financial support from the Estonian Ministry of Education and Science (grant PUT1223). The data collection in Russia was financially supported by RSF grant number 14‐50‐00029. JP was supported by projects CGL2014‐55969‐P and CGL2015‐70639‐P of the Spanish Ministry of Economy and Competitiveness.

The present study aimed to assess the toxicity of seven UV-filters: zinc oxide nanoparticles (nZnO, particle size

The use of functional traits to describe community structure is a promising approach to reveal generalities across organisms and ecosystems. Plant ecologists have demonstrated the importance of traits in explaining community structure, competitive interactions as well as ecosystem functioning. The application of trait-based methods to more complex communities such as food webs is however more challenging owing to the diversity of animal characteristics and of interactions. The objective of this study was to determine how functional structure is related to food web structure. We consider that food web structure is the result of 1) the match between consumer and resource traits, which determine the occurence of a trophic interaction between them, and 2) the distribution of functional traits in the community. We implemented a statistical approach to assess whether or not 35 466 pairwise interactions between soil organisms are constrained by trait-matching and then used a Procrustes analysis to investigate correlations between functional indices and network properties across 48 sites. We found that the occurrence of trophic interactions is well predicted by matching the traits of the resource with those of the consumer. Taxonomy and body mass of both species were the most important traits for the determination of an interaction. As a consequence, functional evenness and the variance of certain traits in the community were correlated to trophic complementarity between species, while trait identity, more than diversity, was related to network topology. The analysis was however limited by trait data availability, and a coarse resolution of certain taxonomic groups in our dataset. These limitations explain the importance of taxonomy, as well as the complexity of the statistical model needed. Our results outline the important implications of trait composition on ecological networks, opening promising avenues of research into the relationship between functional diversity and ecosystem functioning in multi-trophic systems.

Analysis synthesizing 49 tracking studies shows that flexibility in the major determinant of migration duration is insufficient to adjust to ongoing climate change, and is unlikely to explain many of the changes in arrival timing already observed. Predicting the range of variation over which organisms can adjust to environmental change is a major challenge in ecology1,2. This is exemplified in migratory birds which experience changes in different habitats throughout the annual cycle3. Earlier studies showed European population trends declining strongest in migrant species with least adjustment in spring arrival time4,5. Thus, the increasing mismatches with other trophic levels in seasonal breeding areas6,7 probably contribute to their large-scale decline. Here we quantify the potential range of adjusting spring arrival dates through modifying migration speeds by reviewing 49 tracking studies. Among-individual variation in migration speed was mainly determined by the relatively short stop-over duration. Assuming this population response reflects individual phenotypic plasticity, we calculated the potential for phenotypic plasticity to speed-up migration by reducing stop-over duration. Even a 50% reduction would lead to a mere two-day advance in arrival, considering adjustments on the final 2,000 km of the spring journey. Hence, in contrast to previous studies8,9,10, flexibility in the major determinant of migration duration seems insufficient to adjust to ongoing climate change, and is unlikely to explain some of the observed arrival advancements in long-distance migrants.

Recent influxes of warm Atlantic water into the fjords of west Spitsbergen have led to concomitant influx of more temperate and boreal fish species. The changes in the water masses within the fjords naturally affect all trophic levels of the sympagic, benthic, and pelagic food chains in the area. The most abundant marine mammal species in the fjords of west Spitsbergen is the ringed seal (Pusa hispida), which feeds, breeds, and moults in this area. In this study, we used isotopic data from whiskers of two cohorts of adult ringed seals (sampled in 1990 and 2013) to determine whether signals of ecosystem changes were detectable in this top marine predator. Acknowledging the limitations to our understanding of whisker growth in phocid seals, we interpreted the isotopic data from whiskers under two alternate hypotheses of whisker replacement dynamics and the dietary periods that might be represented. Even under the most conservative hypothesis, it is clear from our data that changes in the marine food web of the west Spitsbergen coast have occurred over the last 20 years, and that these are detectable in the isotopes incorporated into higher trophic predators. Concluding which aspect of the food web has been modified is complicated by a lack of recent ringed seal dietary studies, a knowledge gap that should be prioritised as the climate continues to change.

Zooplankton plays a major ecological role mediating the flow of nutrients and energy from phytoplankton to higher trophic levels, including economically important fish species. Mesozooplankton and gelatinous zooplankton are essential indicators of the impacts of climate change on coastal marine systems. Due to shallowness and geographic location, the northern Adriatic biota is exposed to variable hydrographic conditions. The surface temperature has increased at a rate of 0.08±0.01°C y -1, and since the 1980s, the occurrence of marine heatwaves increased, and cold-spells have declined. Reductions in nutrient loading in recent decades were associated with lower chlorophyll‐a and phytoplankton productivity. We explored zooplankton community response to environmental changes during 2006–2016 and compared these results to the literature and own data from an earlier period. The zooplankton biomass and abundance decreased during 2006-2016 compared to 1991-2001. Gelatinous macrozooplankton presented an increasing trend while cladoceran Penilia avirostris, cold water herbivore/omnivore copepods declined.

Aim: Temperature, food resources and top‐down regulation by antagonists are considered as major drivers of insect diversity, but their relative importance is poorly understood. Here, we used cavity‐nesting communities of bees, wasps and their antagonists to reveal the role of temperature, food resources, parasitism rate and land use as drivers of species richness at different trophic levels along a broad elevational gradient. Location: Mt. Kilimanjaro, Tanzania. Taxon: Cavity‐nesting Hymenoptera (Hymenoptera: Apidae, Colletidae, Megachilidae, Crabronidae, Sphecidae, Pompilidae, Vespidae). Methods: We established trap nests on 25 study sites that were distributed over similar large distances in terms of elevation along an elevational gradient from 866 to 1788 m a.s.l., including both natural and disturbed habitats. We quantified species richness and abundance of bees, wasps and antagonists, parasitism rates and flower or arthropod food resources. Data were analysed with generalized linear models within a multi‐model inference framework. Results: Elevational species richness patterns changed with trophic level from monotonically declining richness of bees to increasingly humped‐shaped patterns for caterpillar‐hunting wasps, spider‐hunting wasps and antagonists. Parasitism rates generally declined with elevation but were higher for wasps than for bees. Temperature was the most important predictor of both bee and wasp host richness patterns. Antagonist richness patterns were also well predicted by temperature, but in contrast to host richness patterns, additionally by resource abundance and diversity. The conversion of natural habitats through anthropogenic land use, which included biomass removal, agricultural inputs, vegetation structure and percentage of surrounding agricultural habitats, had no significant effects on bee and wasp communities. Main conclusions: Our study underpins the importance of temperature as a main driver of diversity gradients in ectothermic organisms and reveals the increasingly important role of food resources at higher trophic levels. Higher parasitism rates at higher trophic levels and at higher temperatures indicated that the relative importance of bottom‐up and top‐down drivers of species richness change across trophic levels and may respond differently to future climate change.

International audience; Extensive development of new applications using graphene based materials such as graphene oxide (GO) increases its potential release and occurrence into aquatic environments, raising the question of its biological and ecological risks. As standardized single-species-based assays fail to highlight toxicological pathways implying interactions between organisms, the use of micro/mesocosms appears as a good solution to fill the lack of environmental realism inherent to these tests. In this work, experiments were achieved using microcosm systems to expose a reconstituted food chain to GO at environmentally-relevant concentrations (0.05 and 0.1 mg L−1). The trophic chain was composed of a consortium of algae and bacteria as primary producers, chironomid larvae as primary consumers and decomposers while larvae of the amphibian Pleurodeles waltii constituted the secondary consumers. Monitoring of multiple ecotoxicological and ecological endpoints allowed to observe changes in bacterial communities while no toxic effects were noticed in chironomids. However, chironomids feeding behaviour changed as a consequence of GO contamination, leading to an increase in leaf litter consumption. Genotoxic effects were noticed in Pleurodeles larvae. This study highlights the importance of using such experimental systems to better encompass the ecotoxic potential of GO through the determination of toxicological routes and consequences on ecosystem’s functioning.

Few papers using hydrogen stable isotope analysis for human palaeodietary reconstruction purposes have been published and the usefulness of this additional dietary indicator is highlighted here. The hydrogen stable isotope results provide evidence for the continued exploitation of aquatic resources throughout the prehistory of the Limfjord area in Denmark, which is supported by the FRUITS estimates using three (CNH) isotopic proxies. While aquatic dietary input has been identified in Mesolithic and Viking Age individuals before, our results show that this in fact continued throughout the periods in between (Neolithic, Bronze and Iron Age), albeit on a small scale.

Organismal traits and their evolution can strongly influence food web structure and dynamics. To what extent the evolution of such traits impacts food web structure, however, is poorly understood. Here, we investigate a simple three-species omnivory food web module where the attack rates of all predators evolve as ecological dynamics unfold, such that predator trophic levels are themselves dynamic. We assume a timescale where other vital rates that govern population dynamics are constant and incorporate a well-known tradeoff between attack rates and the conversion of prey into predator biomass. We show that this eco-evolutionary model yields a surprisingly rich array of dynamics. Moreover, even small amounts of selection lead to important differences in the abundance, trophic, and biomass structure of the food web. Systems in which intermediate predators are strongly constrained by tradeoffs lead to hourglass-shaped food webs, where basal resources and top predators have large abundances, but intermediate predators are rare, like those observed in some marine ecosystems. Such food webs are also characterized by a relatively low maximum trophic level. Systems in which intermediate predators have weaker tradeoffs lead to pyramid-shaped food webs, where basal resources are more abundant than intermediate and top predators, such as those observed in some terrestrial system. These food webs also supported a relatively higher maximum trophic level. Overall, our results suggest that eco-evolutionary dynamics can strongly influence the abundance-, trophic-, and biomass-structure of food webs, even in the presence of small levels of selection, thus stressing the importance of taking traits and trait evolution into account to further understand community-level patterns and processes.

1. Climate change may cause phenological asynchrony between trophic levels, which can lead to mismatched reproduction in animals. Although indirect effects of mismatch on fitness are well described, direct effects on parental prey choice are not. Moreover, direct effects of prey variation on offspring condition throughout their early development are understudied.2. Here, we used camera trap data collected over 2 years to study the effects of trophic mismatch and nestling age on prey choice in pied flycatchers (Ficedula hypoleuca). Furthermore, we studied the effect of mismatch and variation in nestling diet on offspring condition.3. Both experimentally induced and natural mismatches with the caterpillar peak negatively affected absolute and relative numbers of caterpillars and offspring condition (mass, tarsus and wing length) and positively affected absolute and relative numbers of flying insects in the nestling diet. Feeding more flying insects was negatively correlated with nestling day 12 mass.4. Both descriptive and experimental data showed preferential feeding of spiders when nestlings were 5. These results highlight the need for a more inclusive framework to study phenological mismatch in nature. The general focus on only one prey type, the rarity of studies that measure environmental abundance of prey, and the lack of timing experiments in dietary studies currently hamper understanding of the actual trophic interactions that affect fitness under climate change.

00001 WOS:000389304800009; International audience; Climate change is inducing deep modifications in local communities worldwide as a consequence of individualistic species range shifts. Understanding how complex interaction networks will be reorganized under climate change represents a major challenge in the fields of ecology and biogeography. However, forecasting the potential effects of climate change on local communities, and more particularly on food-web structure, requires the consideration of highly structuring processes, such as trophic interactions. A major breakthrough is therefore expected by combining predictive models integrating habitat selection processes, the physiological limits of marine species and their trophic interactions. In this study, we forecasted the potential impacts of climate change on the local food-web structure of the highly threatened Gulf of Gabes ecosystem located in the south of the Mediterranean Sea. We coupled the climatic envelope and habitat models to an allometric niche food web model, hence taking into account the different processes acting at regional (climate) and local scales (habitat selection and trophic interactions). Our projections under the A2 climate change scenario showed that future food webs would be composed of smaller species with fewer links, resulting in a decrease of connectance, generality, vulnerability and mean trophic level of communities and an increase of the average path length, which may have large consequences on ecosystem functioning. The unified framework presented here, by connecting food-web ecology, biogeography and seascape ecology, allows the exploration of spatial aspects of interspecific interactions under climate change and improves our current understanding of climate change impacts on local marine food webs.

The oceans are increasingly affected by multiple aspects of global change, with substantial impacts on ecosystem functioning and food‐web dynamics. While the effects of single factors have been extensively studied, it has become increasingly evident that there is a need to unravel the complexities related to a multiple stressor environment. In a mesocosm experimental study, we exposed a simplified, multi‐trophic seagrass ecosystem (composed of seagrass, two shrimp species, and two intermediate predatory fish species) to three global change factors consisting of simulated storm events (Storms), heat shocks (Heat), and ocean acidification (OA), and the combination of all three factors (All). The most striking result indicated that when all factors were combined, there was a negative influence at all trophic levels, while the treatments with individual factors revealed species‐specific response patterns. It appeared, however, that single factors may drive the multi‐stressor response. All single factors (i.e., Storms, Heat, and OA) had either negative, neutral, or positive effects on fish and shrimp, whereas no effect was recorded for any single stressor on seagrass plants. The findings demonstrate that when several global change factors appear simultaneously, they can have deleterious impacts on seagrass ecosystems, and that the nature of factors and food‐web composition may determine the sensitivity level of the system. In a global change scenario, this may have serious and applicable implications for the future of temperate seagrass ecosystems.

Bacterial antibiotic resistance is often a part of mobile genetic elements that move from one bacterium to another. By interfering with the horizontal movement and the maintenance of these elements, it is possible to remove the resistance from the population. Here, we show that a so-called plasmid-dependent bacteriophage causes the initially resistant bacterial population to become susceptible to antibiotics. However, this effect is efficiently countered when the system also contains a predator that feeds on bacteria. Moreover, when the environment contains antibiotics, the survival of resistance is dependent on the resistance mechanism. When bacteria can help their contemporaries to degrade antibiotics, resistance is maintained by only a fraction of the community. On the other hand, when bacteria cannot help others, then all bacteria remain resistant. The concentration of the antibiotic played a less notable role than the antibiotic used. This report shows that the survival of antibiotic resistance in bacterial communities represents a complex process where many factors present in real-life systems define whether or not resistance is actually lost., Mobile genetic elements such as conjugative plasmids are responsible for antibiotic resistance phenotypes in many bacterial pathogens. The ability to conjugate, the presence of antibiotics, and ecological interactions all have a notable role in the persistence of plasmids in bacterial populations. Here, we set out to investigate the contribution of these factors when the conjugation network was disturbed by a plasmid-dependent bacteriophage. Phage alone effectively caused the population to lose plasmids, thus rendering them susceptible to antibiotics. Leakiness of the antibiotic resistance mechanism allowing Black Queen evolution (i.e. a “race to the bottom”) was a more significant factor than the antibiotic concentration (lethal vs sublethal) in determining plasmid prevalence. Interestingly, plasmid loss was also prevented by protozoan predation. These results show that outcomes of attempts to resensitize bacterial communities by disrupting the conjugation network are highly dependent on ecological factors and resistance mechanisms. IMPORTANCE Bacterial antibiotic resistance is often a part of mobile genetic elements that move from one bacterium to another. By interfering with the horizontal movement and the maintenance of these elements, it is possible to remove the resistance from the population. Here, we show that a so-called plasmid-dependent bacteriophage causes the initially resistant bacterial population to become susceptible to antibiotics. However, this effect is efficiently countered when the system also contains a predator that feeds on bacteria. Moreover, when the environment contains antibiotics, the survival of resistance is dependent on the resistance mechanism. When bacteria can help their contemporaries to degrade antibiotics, resistance is maintained by only a fraction of the community. On the other hand, when bacteria cannot help others, then all bacteria remain resistant. The concentration of the antibiotic played a less notable role than the antibiotic used. This report shows that the survival of antibiotic resistance in bacterial communities represents a complex process where many factors present in real-life systems define whether or not resistance is actually lost.

V raziskavi za diplomsko delo smo v letu 2018 na različnih lokacijah vzorčili škodljivce in njihove naravne sovražnike na žitih. Rezultate vzorčenih škodljivcev, njihovih naravnih sovražnikov in parazitoidov smo tabelarično predstavili. Našli smo dve vrsti žitnih uši – Rhopalosiphum padi in Sitobion avenae, med katerima je bila slednja bolj zastopana. Med naravnimi sovražniki listnih uši smo ugotovili 11 različnih vrst, med katerimi je najbolj zastopan primarni parazitoid Aphidius uzbekistanicus. Med sekundarnimi parazitoidi pa je najbolj pogosta vrsta Pachyneuron muscarum. Poleg uši smo vzorčili še 7 drugih škodljivcev, ter ugotovili njihove naravne sovražnike. Povezave med gostiteljskimi rastlinami, škodljivci, naravnimi sovražniki na več nivojih smo predstavili grafično s pomočjo dveh trofičnih mrež. Prva trofična mreža je bila bolj kompleksna, listne uši pa so bile najbolj pogosto vzorčen škodljivec. In the research done in year 2018, we took samples of cereal pests and their natural enemies on different sample locations in Slovenia. The results of samples of cereal pests, their natural enemies and parasitoids were presented tabulary. Two types of cereal aphids were found in our research – Sitobion avenae and Rhopalosiphum padi, first one being the more frequent. 11 different natural enemies of cereal aphids were found with parasitoid Aphidius uzbekistanicus being the most frequent one found. Among secondary parasitoids, Pachyneuron muscarum was sampled most frequently. Beside two types of cereal aphids we also found 7 other types of cereal pests. The connections between different trophic levels were presented with the help of two trophic webs – first one represents the results of cereal aphids and their natural enemies and secondary parasitoids. Second trophic web represents the results for other cereal pests and their natural enemies found in our research. The trophic web for cereal aphids was more complex in comparison to the second trophic web.

The present study describes composition and trophic structure, and assesses the effect of environmental temperature and rainfall on the pattern of nocturnal activity of understory bats in an Andean forest, in the first half of the night. Seven sampling events were conducted, lasting six nights each one. Ten mist nets were used to capture bats, which were checked every hour between 18:00 and 00:00 hours. Bat species, sex and capture time were registered. In addition, environmental temperature and rainfall were also recorded during sampling. The bat assemblage of the understory of the study area was represented mostly by frugivore species, within this guild there was a lower richness of nomadic than sedentary species. For the first half of the night, bat activity peaked between 18:00 and 19:00 hours and declined to a minimum level between 22:00 and 23:00 hours. The most accurate model to explain variation in bat captures included only the effect of air temperature, which positively affected the number of captures. In conclusion, for the sampled period the activity of the bat assemblage in the study area was not related to rainfall and exhibited a slight but significant relationship with air temperature. RESUMEN En el presente trabajo se describe la composición y estructura trófica, y se evalúa el efecto de la temperatura ambiental y la precipitación sobre el patrón de actividad nocturna de los murciélagos de sotobosque que habitan que un bosque Andino, para la primera mitad de la noche. Para esto se realizaron siete campañas de muestreo, con una duración de seis noches cada una, en las que se utilizaron diez redes de niebla que operaron entre las 18:00 y 00:00 horas, siendo revisadas cada hora. Además, se registró la temperatura ambiental y la precipitación durante los eventos de muestreo. El ensamblaje de murciélagos de sotobosque del área de estudio estuvo representado principalmente por especies frugívoras, y dentro de este gremio, se registró una menor riqueza de especies nómadas que sedentarias. La actividad de los murciélagos, para la primera mitad de la noche, fue máxima entre las 18:00 y 19:00 horas, disminuyendo hasta alcanzar una actividad mínima entre las 22:00 y 23:00 horas. El modelo más adecuado para explicar la variación en las capturas de murciélagos incluyó sólo el efecto de la temperatura ambiental, la cual afectó positivamente el número de capturas. En conclusión, para el periodo evaluado, la actividad del ensamble de murciélagos de sotobosque en el área de estudio no se relacionó con la precipitación y exhibió relación leve pero significativa con la temperatura ambiental.

The body of work relating to the gut microbiota of fish is dwarfed by that on humans and mammals. However, it is a field that has had historical interest and has grown significantly along with the expansion of the aquaculture industry and developments in microbiome research. Research is now moving quickly in this field. Much recent focus has been on nutritional manipulation and modification of the gut microbiota to meet the needs of fish farming, while trying to maintain host health and welfare. However, the diversity amongst fish means that baseline data from wild fish and a clear understanding of the role that specific gut microbiota play is still lacking. We review here the factors shaping marine fish gut microbiota and highlight gaps in the research.

The present study describes composition and trophic structure, and assesses the effect of environmental temperature and rainfall on the pattern of nocturnal activity of understory bats in an Andean forest, in the first half of the night. Seven sampling events were conducted, lasting six nights each one. Ten mist nets were used to capture bats, which were checked every hour between 18:00 and 00:00 hours. Bat species, sex and capture time were registered. In addition, environmental temperature and rainfall were also recorded during sampling. The bat assemblage of the understory of the study area was represented mostly by frugivore species, within this guild there was a lower richness of nomadic than sedentary species. For the first half of the night, bat activity peaked between 18:00 and 19:00 hours and declined to a minimum level between 22:00 and 23:00 hours. The most accurate model to explain variation in bat captures included only the effect of air temperature, which positively affected the number of captures. In conclusion, for the sampled period the activity of the bat assemblage in the study area was not related to rainfall and exhibited a slight but significant relationship with air temperature. En el presente trabajo se describe la composición y estructura trófica, y se evalúa el efecto de la temperatura ambiental y la precipitación sobre el patrón de actividad nocturna de los murciélagos de sotobosque que habitan que un bosque Andino, para la primera mitad de la noche. Para esto se realizaron siete campañas de muestreo, con una duración de seis noches cada una, en las que se utilizaron diez redes de niebla que operaron entre las 18:00 y 00:00 horas, siendo revisadas cada hora. Además, se registró la temperatura ambiental y la precipitación durante los eventos de muestreo. El ensamblaje de murciélagos de sotobosque del área de estudio estuvo representado principalmente por especies frugívoras, y dentro de este gremio, se registró una menor riqueza de especies nómadas que sedentarias. La actividad de los murciélagos, para la primera mitad de la noche, fue máxima entre las 18:00 y 19:00 horas, disminuyendo hasta alcanzar una actividad mínima entre las 22:00 y 23:00 horas. El modelo más adecuado para explicar la variación en las capturas de murciélagos incluyó sólo el efecto de la temperatura ambiental, la cual afectó positivamente el número de capturas. En conclusión, para el periodo evaluado, la actividad del ensamble de murciélagos de sotobosque en el área de estudio no se relacionó con la precipitación y exhibió relación leve pero significativa con la temperatura ambiental.

In this study, femoral collagen, rib collagen, femoral muscle, loin muscle and liver samples from sows, piglets and pigs raised in a controlled feeding study are analysed for their nitrogen-isotope compositions. The objectives of this research are to investigate the relationship between tissue and dietary δ15N values across age categories under controlled feeding and housing conditions, and to assess tissue 15N-enrichment relative to diet when pigs of different ages are consuming terrestrial, marine, or mixed terrestrial-marine dietary protein. There is a strong linear relationship between all tissue δ15N values and the amount of marine protein consumed, but the δ15N values do not become consistently elevated for all individuals consuming the same diet until at least 25% of the dietary protein source is marine-derived. Adolescent pigs also had consistently lower δ15N values than either piglets or sows consuming the same diet for collagen and muscle, which is most likely caused by the differences in growth rate among the age categories. Further, for some tissues and animals, a linear relationship between the amount of marine protein consumed and the Δ15NTissue – Whole Diet offset was also observed. We suggest that this variability results from both age-associated growth rates and differential incorporation of amino acids from terrestrial and marine dietary protein into rapidly growing tissue.

Plants leave species-specific legacies in the soil they grow in that can represent changes in abiotic or biotic soil properties. It has been shown that such legacies can affect future plants that grow in the same soil (plant–soil feedback, PSF). Such processes have been studied in detail, but mostly on individual plants. Here, we study PSF effects at the community level and use a trait-based approach both in the conditioning phase and in the feedback phase to study how 12 individual soil legacies influence six plant communities that differ in root size. We tested if (1) grassland perennial species with large root systems would leave a stronger legacy than those with small root systems, (2) grass species would leave a more positive soil legacy than forbs, and (3) communities with large root systems would be more responsive than small-rooted communities. We also tested (4) whether a leaf-chewing herbivore and a phloem feeder were affected by soil legacy effects in a community framework. Our study shows that the six different plant communities that we used respond differently to soil legacies of 12 different plant species and their functional groups. Species with large root systems did not leave stronger legacies than species with small root systems, nor were communities with large root systems more responsive than communities with root systems. Moreover, we show that when communities are affected by soil legacies, these effects carry over to the chewing herbivore Mamestra brassicae (Lepidoptera: Noctuidae) through induced behavioural changes resulting in better performance of a chewing herbivore on forb-conditioned soils than on grass-conditioned soils, whereas performance of the phloem feeder Rhopalosiphum padi (Hemiptera: Aphididae) remained unaffected. Synthesis. The results of this study shed light on the variability of soil effects found in previous work on feedbacks in communities. Our study suggests that the composition of plant communities determines to a large part the response to soil legacies. Furthermore, the responses to soil legacies of herbivores feeding on the plant communities that we observed, suggests that in natural ecosystems, the vegetation history may also have an influence on contemporary herbivore assemblages. This opens up exciting new areas in plant–insect research and can have important implications for insect pest management.

Description of the subject. Intercropping is a kind of polyculture, growing two or more crops together. This practice should improve pest management mainly by increasing predator diversity. It was hypothesized that the intercropping of narrow-leafed lupin with spring triticale would increase the number and diversity of rove beetles compared to monocultures of the aforementioned crops.Objectives. The aim of the research was to determine the effect of intercropping of narrow-leafed lupin with spring triticale on rove beetle abundance and diversity. Method. Over a three-year period, rove beetles were trapped with the use of pitfall traps, and adults were identified to species. The experiment was carried out on a narrow-leafed lupin and spring triticale crop sown as monocultures, and on two mixtures with different proportions of lupin seeds.Results. In total, in all treatments 100 rove beetle species were found, classified into three trophic groups. The most numerous forms were predatory zoophages, which were followed by parasites and saprophages. Staphylinidae abundance and ecological significance decreased with increasing degree of habitat diversity in comparison to crops grown in the pure stand. The same response to intercropping was observed in the case of zoophages.Conclusions. Contrary to what was hypothesized, the abundance and diversity of rove beetle decreased when narrow-leafed lupin and spring triticale were grown together compared to their monoculture. Presumably, the higher abundance of rove beetle in lupin and spring triticale grown in the pure stand is mostly the result of better food supply in monocultures during the whole season., Effet de la culture intercalaire de lupin à feuilles étroites et de triticale de printemps sur l’abondance et la diversité des staphylinsDescription du sujet. La culture intercalaire est un type de polyculture dans laquelle deux cultures, ou plus, sont associées. Cette pratique devrait améliorer la lutte antiparasitaire principalement en augmentant la diversité des prédateurs. L\'hypothèse suivante a été émise : la culture intercalaire de lupin à feuilles étroites et de triticale printanier augmente le nombre et la diversité des staphylins présents, comparativement à des cultures en semis purs.Objectifs. Le but de la recherche était de déterminer l\'effet de la culture intercalaire de lupin à feuilles étroites avec le triticale de printemps sur l\'abondance et la diversité des staphylins.Méthode. Sur une période de trois ans, les staphylins ont été piégés avec l\'utilisation de pièges à fosse et les adultes identifiés jusqu’au stade de l’espèce. Les traitements expérimentaux ont consisté en une culture de lupins à feuilles étroites et de triticale de printemps en peuplement pur et de ses deux mélanges avec une proportion différente de graines de lupin.Résultats. Cent espèces de staphylins ont été trouvées, classées en trois groupes trophiques. Les plus nombreux étaient zoophages, suivis par les parasitoïdes et les saprophages. L\'abondance et l’importance écologique des Staphylinidae diminuaient avec l’augmentation de la diversité de l\'habitat, par rapport aux cultures pratiquées en peuplement pur. La même réponse à la culture intercalaire a été observée dans le cas des zoophages.Conclusions. Contrairement à l’hypothèse de départ, notre recherche démontre que l\'abondance et la diversité des staphylins sont moindres dans les cultures intercalaires que dans les monocultures de lupin à feuilles étroites et de triticale de printemps. L\'abondance plus élevée de staphylins dans les cultures en semis purs de lupin et de triticale de printemps peut être expliquée par une meilleure alimentation en monoculture durant toute la saison.

Foraging success of predators profoundly depends on reliable and detectable cues indicating the presence of their often inconspicuous prey. Carnivorous insects rely on chemical cues to optimize foraging efficiency. Hyperparasitoids that lay their eggs in the larvae or pupae of parasitic wasps may find their parasitoid hosts developing in different herbivores. They can use herbivore-induced plant volatiles (HIPVs) to locate parasitized caterpillars. Because different herbivore species induce different HIPV emission from plants, hyperparasitoids may have to deal with large variation in volatile information that indicates host presence. In this study, we used an ecogenomics approach to first address whether parasitized caterpillars of two herbivore species (Pieris rapae and P. brassicae) induce similar transcriptional and metabolomic responses in wild Brassica oleracea plants and, second, whether hyperparasitoids Lysibia nana are able to discriminate between these induced plant responses to locate their parasitoid host in different herbivores under both laboratory and field conditions. Our study revealed that both herbivore identity and parasitism affect plant transcriptional and metabolic responses to herbivory. We also found that hyperparasitoids are able to respond to HIPVs released by wild B. oleracea under both laboratory and field conditions. In addition, we observed stronger attraction of hyperparasitoids to HIPVs when plants were infested with parasitized caterpillars. However, hyperparasitoids were equally attracted to plants infested by either herbivore species. Our results indicate that parasitism plays a major role in HIPV-mediated plant-hyperparasitoid interactions. Furthermore, these findings also indicate that plant trait-mediated indirect interaction networks play important roles in community-wide species interactions.

Metabarcoding of marine environmental DNA (eDNA), the DNA suspended in seawater originating from tissue, cells, or extracellular DNA, offers the opportunity to survey the biological composition of communities across multiple trophic levels from a non-invasive seawater sample. Here we compare results of eDNA metabarcoding of multiple trophic levels from the same seawater samples collected from a kelp forest in Monterey Bay, California in order to establish methods for future cross-trophic level eDNA analysis. Triplicate 1 L water samples were filtered using five different 47 mm diameter membrane filters (PVDF, PES, GFF, PCTE, and NC) and DNA was extracted from triplicates of each filter-type using three widely-used extraction methods (the DNeasy Blood and Tissue kit, the MoBio PowerWater DNA Isolation kit, and standard phenol/chloroform methods) resulting in 45 individual eDNA samples prepared with 15 workflow combinations. Each DNA extract was amplified using PCR primers for the 16S rRNA gene (microorganisms; Bacteria and Archaea), 18S rRNA gene (phytoplankton), and the 12S rRNA gene (vertebrates) genes, and PCR products were sequenced on an Illumina MiSeq platform. The richness and community composition of microbial, phytoplankton, and vertebrate OTUs were not significantly different between any of the 0.2 μm pore-size filter types extracted with the DNeasy or MoBio kits. However, phenol/chloroform extraction resulted in significantly different community structures. This study provides insight into multiple choices for extraction and filtration methods to use eDNA metabarcoding for biodiversity assessment of multiple trophic levels from a single sample. We recommend any combination of either DNeasy or MoBio with PES, PCTE, PVDF, or NC filters for a cross trophic level comparison.

In this study we updated the previous compilation of the feeding habits and trophic levels (TROPHs) of Mediterranean fish. In total, 172 publications were retrieved and analysed. Collected data refer to 146 species, with a TROPH value ranging from 2.00 to 4.54. The analysis of TROPH distribution verified the previously proposed classification of species into functional trophic groups. Overall, information on diet composition exits for 203 fish species out of the >700 fishes from the Mediterranean, a fact clearly showing that feeding habits are understudied despite their importance in ecological applications and fisheries management. More than half (60.6%) of these species are classified as omnivores with preference to animal material, 36.5% are carnivores, 1.9% are omnivores with preference to plants, and two (i.e. Siganus luridus and S. rivulatus) are pure herbivores. Finally, towards the direction of filling in information gaps, recommendations for future research are given.

Overfishing has eliminated up to 90% of predatory reef fishes, but recovery potential is still high in several Caribbean reefs., The natural, prehuman abundance of most large predators is unknown because of the lack of historical data and a limited understanding of the natural factors that control their populations. Determining the supportable predator biomass at a given location (that is, the predator carrying capacity) would help managers to optimize protection and would provide site-specific recovery goals. We assess the relationship between predatory reef fish biomass and several anthropogenic and environmental variables at 39 reefs across the Caribbean to (i) estimate their roles determining local predator biomass and (ii) determine site-specific recovery potential if fishing was eliminated. We show that predatory reef fish biomass tends to be higher in marine reserves but is strongly negatively related to human activities, especially coastal development. However, human activities and natural factors, including reef complexity and prey abundance, explain more than 50% of the spatial variation in predator biomass. Comparing site-specific predator carrying capacities to field observations, we infer that current predatory reef fish biomass is 60 to 90% lower than the potential supportable biomass in most sites, even within most marine reserves. We also found that the scope for recovery varies among reefs by at least an order of magnitude. This suggests that we could underestimate unfished biomass at sites that provide ideal conditions for predators or greatly overestimate that of seemingly predator-depleted sites that may have never supported large predator populations because of suboptimal environmental conditions.

International audience; Dispersal, the behaviour ensuring gene flow, tends to covary with a number of morphological, ecological and behavioural traits. While species-specific dispersal behaviours are the product of each species' unique evolutionary history, there may be distinct interspecific patterns of covariation between dispersal and other traits ('dispersal syndromes') due to their shared evolutionary history or shared environments. Using dispersal, phylogeny and trait data for 15 terrestrial and semi-terrestrial animal Orders (> 700 species), we tested for the existence and consistency of dispersal syndromes across species. At this taxonomic scale, dispersal increased linearly with body size in omnivores, but decreased above a critical length in herbivores and carnivores. Species life history and ecology significantly influenced patterns of covariation, with higher phylogenetic signal of dispersal in aerial dispersers compared with ground dwellers and stronger evidence for dispersal syndromes in aerial dispersers and ectotherms, compared with ground dwellers and endotherms. Our results highlight the complex role of dispersal in the evolution of species life-history strategies: good dispersal ability was consistently associated with high fecundity and survival, and in aerial dispersers it was associated with early maturation. We discuss the consequences of these findings for species evolution and range shifts in response to future climate change.

The signal crayfish Pacifastacus leniusculus Dana, 1852 is a successful invasive species in the Iberian Peninsula. This is of particular conservation concern, as fish fauna is highly endemic and also threatened within this ecoregion. The aim of this study was to analyze behavioral interactions and trophic overlap between signal crayfish and native fishes in Iberian rivers (northern Spain). Video cameras were used to record fish &ldquo, dominance/evasion&rdquo, after spatial encounters with crayfish. Diet composition and isotopic signatures (&delta, 13C and &delta, 15N) were compared to evaluate the niche overlap. Fish were dominant in 25% of the encounters with juvenile crayfish, whereas this percentage was only 4% with adult crayfish. Observations showed a high fish &ldquo, evasion&rdquo, response for Pyrenean stone loach Barbatula quignardi (Bǎcescu-Meşter, 1967) (&gt, 30%). Dietary results showed a high trophic overlap between signal crayfish with the pelagic Pyrenean minnow Phoxinus bigerri Kottelat, 2007 and the benthic loach. However, the isotopic niche overlap was low, with brown trout Salmo trutta L., 1758 showing the highest area (only 0.1 &permil, 2). Overall, our findings suggest that interferences may occur with native species for food (i.e., benthic invertebrates). Consequently, measures should be applied to control invasive crayfish in Iberian rivers.

Comparing outputs of ecosystem models with estimates derived from experimental and observational approaches is important in creating valuable feedback for model construction, analyses and validation. Stable isotopes and mass-balanced trophic models are well-known and widely used as approximations to describe the structure of food webs, but their consistency has not been properly established as attempts to compare these methods remain scarce. Model construction is a data-consuming step, meaning independent sets for validation are rare. Trophic linkages in the French continental shelf of the Bay of Biscay food webs were recently investigated using both methodologies. Trophic levels for mono-specific compartments representing small pelagic fish and marine mammals and multi-species functional groups corresponding to demersal fish and cephalopods, derived from modelling, were compared with trophic levels calculated from independent carbon and nitrogen isotope ratios. Estimates of the trophic niche width of those species, or groups of species, were compared between these two approaches as well. A significant and close-to-one positive (, n=16,p&nbsp

The benthic foodweb structure of Lake Võrtsjärv, a large (270 km2), shallow, and turbid Estonian lake, was evaluated based on C and N stable-isotope signatures (δ13C, δ15N). Variation in δ13C between sampling sites was not related to site proximity to the littoral zone or the more vegetated southern part of the lake, but rather appeared to be influenced by in-situ site peculiarities. δ13C was stable temporally and between functional feeding groups, a result implying that the whole benthic food web of the lake relies largely on the same C source admixture, essentially particulate organic matter (POM). Thus, the foodweb composition of Lake Võrtsjärv is remarkably homogeneous given the lake’s large surface area. Apparent trophic-level δ15N fractionation between total collectors and total predators (mean 1.7‰) was lower than the value of 3.4‰ generally adopted in foodweb studies, but the higher value was valid for specific prey–predator links. The low δ13C signature of some chironomid samples indicated probable assimilation of methane-oxidizing bacteria (MOB) by these sediment-dwelling invertebrates. However, the lack of similar 13C depletion in benthic filterers (mussels) indicated that the MOB layer is essentially confined to the sediments and does not reach the water column, which probably constrains transfer of methane-derived C through the food web to fish in this lake. Our study demonstrates that the benthic food web of shallow turbid lakes like Võrtsjärv is simplified and is mostly sustained by phytoplanktonic C sources. peerReviewed

Introduction. Integrated management of wireworms (Coleoptera: Elateridae) depends upon approaches applied both above- and belowground, and over several spatial scales. While foraging, these soil pests use biotic and abiotic signals to orientate towards target plant organs. Development of efficient techniques for implementation in integrated strategies relies upon improved knowledge of this process. In particular, an important step consists of elucidating the role of volatile organic compounds (VOC), emitted by belowground plant organs, in wireworm chemical ecology. This would have a positive impact on push-pull strategies and varietal selection developed against these insects. Literature. In this work, we summarized the available data regarding wireworm foraging behavior as well as variables that should be considered when studying the potential role of plant-produced volatile semiochemicals. This includes CO2 gradients and other host-related cues, temperature, relative humidity and soil moisture, and wireworm physiological stage. We also review what is known of the sensory apparatus of wireworms, since this is involved in every step of the foraging process. Conclusion. Some baseline data for studying VOC related wireworm foraging behavior exists. Using it as a tool in applied entomology should result in discovery of the semiochemicals that underpin trophic interactions involving these pests. However, most of the key pest species are not fully described with regards to the parameters detailed here. Obtaining accurate information to fill the current knowledge gaps will be needed in order to devise new integrated management strategies.

In this study, concentration of mercury was determined in the trophic levels of benthic, benthopelagic, pelagic fish species, and river birds from Arvand River, located in the Khuzestan province in the lowlands of southwestern Iran at the head of the Persian Gulf. The order of mercury concentrations in tissues of the fish species was as follows: livergillmuscle and in tissues of the kingfisher species was as follows: featherliverkidneymuscle. Therefore, liver in fish and feather in kingfisher exhibited higher mercury concentration than the other tissues. There was a positive correlation between mercury concentrations in fish and kingfisher species with size of its food items. We expected to see higher mercury levels in tissues of female species because they are larger and can eat larger food items. The results of this study show that the highest mean mercury level were found in the kingfisher (Anas crecca), followed by benthic (Epinephelus diacanthus), benthopelagic (Chanos chanos), and pelagic fish (Strongylura strongylura). Mean value of mercury in fish species, S. strongylura were (0.61 μg g(-1) dry weight), C. chanos (0.45 μg g(-1) dry weight), E. diacanthus (0.87 μg g(-1) dry weight), and in kingfisher species A. crecca was (2.64 μg g(-1) dry weight). Significant correlation between mercury concentration in fish and kingfisher may be related to high variability of mercury in the fish.

Carabids are a species-rich group (more than 10 000 species in the Palaearctic region) and are intensively studied, inter alia due to their roles as bioindicators and mediators of nutrient flows in ecosystems. Numerous aspects of species' systematics, distribution, evolutionary biology (and phylogeny) and their ecology are well documented for the western Palaearctic and large data sets have already been compiled for macroecological studies. 2. The online database carabids.org is an enhancement of these data sets and holds species classification and country level data on species distribution range for over 10 000 Palaearctic carabid species. Size and dispersal traits (body and eye size and hind wing development) are available for almost all (over 3400) western Palaearctic carabid species and ecological and life-history traits (regard- ing food and habitat preferences as well as time of reproduction and activity) can be offered for most Central European (about 1000) species. 3. Carabids.org is meant to be a collaborative and interactive project offering a variety of research opportunities. Our project contributes to the rapid expan- sion and analysis of freely available traits data on species-rich invertebrates, which will help to advance our understanding of community assembly and func- tional diversity effects of such taxa across large spatial scales. We would very much appreciate data contributions from carabidologists, other scientists and interested parties.

Currently, fungicides are necessary to protect potato crops against late blight, Phytophthora infestans, one of the world’s most damaging crop pathogens. The introgression of plant resistance genes from wild potato species targeted specifically to the late blight pathogen into susceptible potato varieties may alleviate the environmental impact of chemical control. Genetically modified plants are subject to an environmental risk assessment, and this includes testing for risks to the non-target arthropod community associated with the crop. The thesis begins with a review about the main plant defense responses and their role in influencing sequential interactions between herbivores and plant pathogens. The experimental chapters each focus on different aspects of the interaction between potato plants (both resistant and susceptible), the target pathogen (P. infestans) and several non-target insects. With each chapter, the scope widens: from the molecular gene expression in potato leaves in response to sequential attacks, to field scale biodiversity analyses. At the molecular level, one of the main findings was that the genomic position of the Rpi-vnt1 insertion conferring resistance to P. infestans influenced potato gene expression measured in leaves, when interacting with the non-target insect pests Myzus persicae (Green peach aphid) and Leptinotarsa decemlineata (Colorado potato beetle). Insect performance differed between the resistant GM and susceptible non-GM comparator. In the following chapter, the differences in insect performance were tested across a range of conventionally bred cultivars varying in resistance to P. infestans. Differences in M. persicae performance between several cultivars greatly outweighed the differences previously detected between the GM and non-GM comparator. These results are crucial in shaping the way risk is assessed in the context of GM crops, and these results are supported in our experiments assessing effects on biodiversity with pitfall traps in the field. The third trophic level was also addressed by comparing the performance of the parasitoid Aphidius colemani reared on GM and non-GM fed aphids, both with an without exposure to P. infestans. Differences in parasitoid performance were only found on the susceptible cultivar when inoculated with P. infestans. In the last experimental chapter the risk assessment is taken to the field comparing pitfall trap catches over two years and in two countries. Different methods for statistical analysis of biodiversity data were compared to arrive at recommendations for such analysis in the framework of environmental risk assessments. Drawing on these lessons, the discussion ends with ideas for the development of protocols for environmental risk assessments in the light of expected scientific progress in agricultural biotechnology.

Currently, fungicides are necessary to protect potato crops against late blight, Phytophthora infestans, one of the world’s most damaging crop pathogens. The introgression of plant resistance genes from wild potato species targeted specifically to the late blight pathogen into susceptible potato varieties may alleviate the environmental impact of chemical control. Genetically modified plants are subject to an environmental risk assessment, and this includes testing for risks to the non-target arthropod community associated with the crop. The thesis begins with a review about the main plant defense responses and their role in influencing sequential interactions between herbivores and plant pathogens. The experimental chapters each focus on different aspects of the interaction between potato plants (both resistant and susceptible), the target pathogen (P. infestans) and several non-target insects. With each chapter, the scope widens: from the molecular gene expression in potato leaves in response to sequential attacks, to field scale biodiversity analyses. At the molecular level, one of the main findings was that the genomic position of the Rpi-vnt1 insertion conferring resistance to P. infestans influenced potato gene expression measured in leaves, when interacting with the non-target insect pests Myzus persicae (Green peach aphid) and Leptinotarsa decemlineata (Colorado potato beetle). Insect performance differed between the resistant GM and susceptible non-GM comparator. In the following chapter, the differences in insect performance were tested across a range of conventionally bred cultivars varying in resistance to P. infestans. Differences in M. persicae performance between several cultivars greatly outweighed the differences previously detected between the GM and non-GM comparator. These results are crucial in shaping the way risk is assessed in the context of GM crops, and these results are supported in our experiments assessing effects on biodiversity with pitfall traps in the field. The third trophic level was also addressed by comparing the performance of the parasitoid Aphidius colemani reared on GM and non-GM fed aphids, both with an without exposure to P. infestans. Differences in parasitoid performance were only found on the susceptible cultivar when inoculated with P. infestans. In the last experimental chapter the risk assessment is taken to the field comparing pitfall trap catches over two years and in two countries. Different methods for statistical analysis of biodiversity data were compared to arrive at recommendations for such analysis in the framework of environmental risk assessments. Drawing on these lessons, the discussion ends with ideas for the development of protocols for environmental risk assessments in the light of expected scientific progress in agricultural biotechnology.