TY - JOUR A1 - Eccard, Jana T1 - Can rolling composite wildflower blocks increase biodiversity in agricultural landscapes better than wildflowers strips? JF - Journal of applied ecology : an official journal of the British Ecological Society N2 - Biodiversity and abundance of wildlife has dramatically declined in agricultural landscapes. Sown, short-lived wildflower (WF) strips along the margins of crop fields are a widespread and often subsidised in agri-environmental schemes, intended to enhance biodiversity, provide refuges for wild plant and arthropod populations and to provide ecosystem services to crops. Meanwhile, WF elements are also criticised, since their functionality decreases with plant succession, the removal of aged WF strip poses an ecological trap for the attracted arthropod populations and only common and mobile species benefit. Further, insects in WF strips are impacted by pesticides from agricultural fields due to shared boundaries with crop fields and by edge effects. The performance of the measure could be improved by combining several WF strips of different successional stages, each harbouring a unique community of plants and arthropods, into persistent, composite WF block, where successional stages exist in parallel. Monitoring data on many taxa in the literature shows, that a third of species are temporarily present in an ageing WF stip, thus offering composite WF blocks should increase cumulative species richness by 28%-39% compared to annual richness in WF strips. Persistence of composite WF blocks would offer reliable refuge for animal and plant populations, also supporting their predators and herbivores. Further, WF blocks have less boundaries to crops compared to WF strips of the same area, and are less impacted by edge effects and pesticides. Policy implications. Here I suggest a change of conservation practice changing from successional WF strips to composite WF blocks. By regular removal and replacement of aged WF strips either within the block (rotational) or at its margins (rolling), the habitat heterogeneity in composite WF block could be perpetuated. Rolling composite WF blocks change locations over years, and the original location can be reconverted to arable land while a nearby WF block is still available to wildlife. A change in agricultural schemes would be necessary, since in some European countries clustered WF strips are explicitly not subsidised. KW - AES KW - agriculture KW - biodiversity KW - CAP KW - conservation scheme KW - field margins KW - insects Y1 - 2022 U6 - https://doi.org/10.1111/1365-2664.14147 SN - 0021-8901 SN - 1365-2664 VL - 59 IS - 5 SP - 1172 EP - 1177 PB - Wiley-Blackwell CY - Oxford ER - TY - JOUR A1 - Engels, Stefan A1 - Medeiros, Andrew S. A1 - Axford, Yarrow A1 - Brooks, Steve A1 - Heiri, Oliver A1 - Luoto, Tomi P. A1 - Nazarova, Larisa B. A1 - Porinchu, David F. A1 - Quinlan, Roberto A1 - Self, Angela E. T1 - Temperature change as a driver of spatial patterns and long-term trends in chironomid (Insecta: Diptera) diversity JF - Global change biology N2 - Anthropogenic activities have led to a global decline in biodiversity, and monitoring studies indicate that both insect communities and wetland ecosystems are particularly affected. However, there is a need for long-term data (over centennial or millennial timescales) to better understand natural community dynamics and the processes that govern the observed trends. Chironomids (Insecta: Diptera: Chironomidae) are often the most abundant insects in lake ecosystems, sensitive to environmental change, and, because their larval exoskeleton head capsules preserve well in lake sediments, they provide a unique record of insect community dynamics through time. Here, we provide the results of a metadata analysis of chironomid diversity across a range of spatial and temporal scales. First, we analyse spatial trends in chironomid diversity using Northern Hemispheric data sets overall consisting of 837 lakes. Our results indicate that in most of our data sets, summer temperature (T-jul) is strongly associated with spatial trends in modern-day chironomid diversity. We observe a strong increase in chironomid alpha diversity with increasing T-jul in regions with present-day T-jul between 2.5 and 14 degrees C. In some areas with T-jul > 14 degrees C, chironomid diversity stabilizes or declines. Second, we demonstrate that the direction and amplitude of change in alpha diversity in a compilation of subfossil chironomid records spanning the last glacial-interglacial transition (similar to 15,000-11,000 years ago) are similar to those observed in our modern data. A compilation of Holocene records shows that during phases when the amplitude of temperature change was small, site-specific factors had a greater influence on the chironomid fauna obscuring the chironomid diversity-temperature relationship. Our results imply expected overall chironomid diversity increases in colder regions such as the Arctic under sustained global warming, but with complex and not necessarily predictable responses for individual sites. KW - Arctic KW - biodiversity KW - climate warming KW - freshwater ecosystems KW - insects KW - palaeoecology KW - Quaternary Y1 - 2019 U6 - https://doi.org/10.1111/gcb.14862 SN - 1354-1013 SN - 1365-2486 VL - 26 IS - 3 SP - 1155 EP - 1169 PB - Wiley CY - Hoboken ER -