Search

Introduced plants become decoupled from their usual pollinators and by relying on resident pollinator species or other reproductive strategies become established in new areas, spread and, eventually, invade. Here, using breeding system experiments, we studied the reproductive biology of the bird-pollinated South American species Nicotiana glauca across native and non-native areas, both inside and outside the range of flower-visiting birds. In the native range, where the species is visited by hummingbirds, open cross-pollinated flowers set as many seeds and almost as many fruits as open pollination controls, suggesting that pollinators make a major contribution to reproductive success. In South Africa, the flowers were pollinated by sunbirds which, although less efficiently, also contributed to N. glauca reproduction, replacing hummingbirds. In contrast, in Mallorca, where nectar feeding birds are absent, fruit production in open cross-pollinated flowers was near zero, and significantly lower than in open pollination controls, suggesting that reproduction is almost entirely by autonomous self-pollination. Hand-pollination experiments showed that the species is self-compatible throughout its range. Pollinator exclusion experiment showed that N. glauca relies on self-pollination only in pollinator poor areas, where plants have a much higher capacity for autonomous self-pollination than elsewhere. A reduction in anther-stigma distance does not seem to account the higher self-pollination capacity in the non-native environment without pollinators. Despite probable evolutionary adaptation, and flexibility in pollinator association and mating system, seed production in the introduced range was somewhat pollen limited, suggesting that the mismatch between N. glauca and its novel pollination environment might retard invasion., Funding for this research was provided by the National Research Council of Argentina (CONICET), the National Ministry of Science and Technology of Argentina, the Department of Science and Technology of South Africa and the Spanish Research Council (CSIC).

15 pages, 2 figures, 4 tables, 1 appendix.-- The data/code that support the findings of this study are available on request from the corresponding author, [E.M.L.]. The data/code are not publicly available because of ongoing research, Although an ecosystem approach to fisheries has been recognized as a means of progressing toward sustainable fishing, successful implementation of this approach has been limited. However, one way in which progress has been made is through the use of suites of indicators. Decision tree frameworks can be used to incorporate trends in ecological, fishing, and environmental indicators into ecosystem assessments. A relatively generic decision tree framework has been developed and successfully applied to multiple ecosystems. This framework incorporates trends in indicators, as well as the impacts of fishing pressure and environmental variability on ecological indicators in order to assess the state of each ecosystem. The inclusion of ecosystem expert knowledge from the outset ensures trends are correctly interpreted and allows analyses to contribute to global comparisons in a robust and meaningful manner. Although ecological and environmental indicators are well developed, those addressing the human dimensions of marine ecosystems are less so. This framework holds the potential to incorporate such indicators in order to fully assess marine ecosystems in a comparative context. Such assessments could help ensure food security from marine resources into the future as well as ensuring the well-being of coastal communities. Here critical review of the potential value of this framework has been conducted, with its usefulness emphasized in the similarities it holds, and in the contribution it could make, to current global methods of ecosystem assessments, This study was funded by the South African Scientific Research Chair Initiative, of the Department of Science and Technology and administered by the National Research Foundation (NRF), through the chair in Marine Ecology and Fisheries. C.L. was supported by the Department for Environment, Food & Rural Affairs of the UK (project MF1228 “Physics to Fisheries”). M.C. was supported by the Spanish Ministry of Economy, Industry and Competitively through the project PELWEB (I+D+I 2018-2020), With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)

Shin, Yunne-Jai ... et al.-- This is a contribution to the IndiSeas Working Group, co-funded by IOC-UNESCO and the Euromarine Consortium in 2015.-- 10 pages, 4 figures, 2 tables, supplementary data https://doi.org/10.1016/j.ecolind.2018.01.010, Ecological indicators are widely used to characterise ecosystem health. In the marine environment, indicators have been developed to assess the ecosystem effects of fishing to support an ecosystem approach to fisheries. However, very little work on the performance and robustness of ecological indicators has been carried out. An important aspect of robustness is that indicators should respond specifically to changes in the pressures they are designed to detect (e.g. fishing) rather than changes in other drivers (e.g. environment). We adopted a multi-model approach to compare and test the specificity of commonly used ecological indicators to capture fishing effects in the presence of environmental change and under different fishing strategies. We tested specificity in the presence of two types of environmental change: “random” representing interannual climate variability and “directional” representing climate change. We used phytoplankton biomass as a proxy of the environmental conditions, as this driver was comparable across all ecosystem models, then applied a signal-to-noise ratio analysis to test the specificity of indicators with random environmental change. For directional change, we used mean gradients to apportion the quantity of change in the indicators due to fishing and the environment. We found that depending on the fishing strategy and environmental change, ecological indicators could range from high to low specificity to fishing. As expected, the specificity of indicators to fishing almost always decreased as environmental variability increased. In 55–76% of the scenarios run with directional change in phytoplankton biomass across fishing strategies and ecosystem models, indicators were significantly more responsive to changes in fishing than to changes in phytoplankton biomass. This important result makes the tested ecological indicators good candidates to support fisheries management in a changing environment. Among the indicators, the catch over biomass ratio was most often the most specific indicator to fishing, whereas mean length was most often the most sensitive to change in phytoplankton biomass. However, the responses of indicators were highly variable depending on the ecosystem and fishing strategy under consideration. We therefore recommend that indicators should be tested in the particular ecosystem before they are used for monitoring and management purposes, L.J.S was supported through the South African Research Chair Initiative, funded through the South African Department of Science and Technology and administered by the South African National Research Foundation. J.E.H., L.V., and Y.J.S were funded by the EMIBIOS project (FRB Fondation pour la Recherche sur la Biodiversité, contract n°APP-SCEN-2010-II). J.E.H. was supported by a Beaufort Marine Research Award carried out under the Sea Change Strategy and the Strategy for Science Technology and Innovation (2006–2013), with the support of the Marine Institute, funded under the Marine Research Sub-Programme of the Irish National Development Plan 2007–2013. L.J.S and Y.J.S. were funded by the European project MEECE (FP7, contract n°212085). M.C. was supported by a Marie Curie CIG grant to BIOWEB project and the Spanish Research Program Ramon y Cajal. Funding from CSIRO and the Australian Fisheries Research and Development Corporation on behalf of the Australian Government supported the development of Atlantis-SE. J.J.H was supported by the UK Natural Environment Research Council and Department for Environment, Food and Rural Affairs under the project MERP: Grant No. NE/L003279/1, Marine Ecosystems Research Programme

Reed, Jodie ... et al.-- 12 pages, 4 figures, supplementary data and supplementary material https://doi.org/10.1093/icesjms/fsw150, Trophic level (TL)-based indicators are commonly used to track the ecosystem effects of fishing as the selective removal of organisms from the food web may result in changes to the trophic structure of marine ecosystems. The use of a fixed TL per species in the calculation of TL-based indicators has been questioned, given that species’ TLs vary with ontogeny, as well as over time and space. We conducted a model-based assessment of the performance of fixed TL-based indicators vs. variable TL-based indicators for tracking the effects of fishing pressure. This assessment considered three TL-based indicators (the trophic level of the landed catch (TLc), the marine trophic index (MTI) and the trophic level of the surveyed community (TLsc)), three fishing scenarios that targeted specific model groups (the low TL scenario (LTL), the high TL scenario (HTL) and a scenario encompassing broad-scale exploitation (ALL)) and ten contrasting marine ecosystems with four types of ecosystem modelling approaches that differ in their structure and assumptions. Results showed that, overall, variable TL-based indicators have a greater capacity for detecting the effects of fishing pressure than fixed TL-based indicators. Across TL-based indicators, TLsc displayed the most consistent response to fishing whether fixed or variable species' TLs were used, as well as the highest capacity for detecting fishing effects. This result supports previous studies that promote the use of survey-based indicators over catch-based indicators to explore the impacts of fishing on the structure of marine ecosystems. Across fishing scenarios, the low trophic level fishing scenario (LTL) resulted in the lowest consistency between fixed and variable TL-based indicator responses and the lowest capacity of TL-based indicators for detecting fishing effects. Overall, our results speak to the need for caution when interpreting TL-based indicator trends, and knowledge of the broader context, such as fishing strategies and exploitation history, This study was funded by Euromarine and the EMIBIOS project (FRB Fondation pour la Recherche sur la Biodiversité, Contract no. APP-SCEN-2010-II). JR was funded by the French-South African ICEMASA program and IRD. LS was supported through the South African Research Chair Initiative, funded through the South African Department of Science and Technology (DST) and administered by the South African National Research Foundation (NRF), as well as through additional funding granted by IRD. AG was supported by NOAA’s Integrated Ecosystem Assessment (IEA) programme (http://www.noaa.gov/iea/). GH was funded by IRD-DPF PhD fellowships program of the Institut de Recherche pour le Développement (IRD). JEH was supported by a Beaufort Marine Research Award carried out under the Sea Change Strategy and the Strategy for Science Technology and Innovation (2006–2013), with the support of the Marine Institute, funded under the Marine Research Sub-Programme of the Irish National Development Plan 2007–2013. JJH was supported by the Natural Environment Research Council and Department for Environment, Food and Rural Affairs under the project MERP: Grant no. NE/L003279/1, Marine Ecosystems Research Programme

International audience; The harlequin ladybird, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), is native to Asia but has been intentionally introduced to many countries as a biological control agent of pest insects. In numerous countries, however, it has been introduced unintentionally. The dramatic spread of H. axyridis within many countries has been met with considerable trepidation. It is a generalist top predator, able to thrive in many habitats and across wide climatic conditions. It poses a threat to biodiversity, particularly aphidophagous insects, through competition and predation, and in many countries adverse effects have been reported on other species, particularly coccinellids. However, the patterns are not consistent around the world and seem to be affected by many factors including landscape and climate. Research on H. axyridis has provided detailed insights into invasion biology from broad patterns and processes to approaches in surveillance and monitoring. An impressive number of studies on this alien species have provided mechanistic evidence alongside models explaining large-scale patterns and processes. The involvement of citizens in monitoring this species in a number of countries around the world is inspiring and has provided data on scales that would be otherwise unachievable. Harmonia axyridis has successfully been used as a model invasive alien species and has been the inspiration for global collaborations at various scales. There is considerable scope to expand the research and associated collaborations, particularly to increase the breadth of parallel studies conducted in the native and invaded regions. Indeed a qualitative comparison of biological traits across the native and invaded range suggests that there are differences which ultimately could influence the population dynamics of this invader. Here we provide an overview of the invasion history and ecology of H. axyridis globally with consideration of future research perspectives. We reflect broadly on the contributions of such research to our understanding of invasion biology while also informing policy and people.