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The Hebrides of Scotland constitute a unique set of island environments with a long history of human settlement and agriculture. Earthworm community surveys were undertaken in selected agricultural landscapes of Inner (Isle of Rum) and Outer (North and South Uist) Hebrides. On North Uist, earthworms were sampled from areas of Blackland (organic, anthropic, acidic agricultural soils) and on South Uist in machair (sandy, fertile, low-lying grassy pasture). Specific grassland and cultivated areas with various organic additions - including dung and seaweed - were targeted, using hand-sorting of soil for earthworms plus mustard vermifuge extraction. Work on Rum investigated earthworms in ridge and furrow (lazybed) agricultural systems, abandoned almost 200 years ago and since uncultivated, but grazed by ungulates. On the Uists, nine earthworm species were identified, representing all three ecological categories, but dominated by the epigeics, Dendrobaena octaedra and Lumbricus rubellus. Densities and biomasses across Blackland soils ranged from 10-130 ind. m−2 and 2.3–33.7 g m−2, respectively. Here, 5 species were present, and management had a significant effect on species richness and abundance with most earthworms present in recently restored lazybeds. In the machair soils, the corresponding measurements were 4–220 ind. m−2 and 0.8–89.0 g m−2. Significantly higher earthworm densities and biomasses were recovered below cattle dung pats compared with dung-free areas. Cultivated areas in machair were less diverse and had lower earthworm densities than uncultivated. On Rum, ridge and furrow abundances did not differ clearly with 24–102 and 34–112 ind. m−2 respectively and biomasses of 7.4–26.3 and 8.8–30.8 g m−2. Here, Aporrectodea caliginosa (49%), L. rubellus (23%) and Dendrodrilus rubidus (19%) dominated of the seven species found. Further research on earthworms in the Hebrides is warranted.

Soil organisms, including earthworms, are a key component of terrestrial ecosystems. However, little is known about their diversity, their distribution, and the threats affecting them. We compiled a global dataset of sampled earthworm communities from 6928 sites in 57 countries as a basis for predicting patterns in earthworm diversity, abundance, and biomass. We found that local species richness and abundance typically peaked at higher latitudes, displaying patterns opposite to those observed in aboveground organisms. However, high species dissimilarity across tropical locations may cause diversity across the entirety of the tropics to be higher than elsewhere. Climate variables were found to be more important in shaping earthworm communities than soil properties or habitat cover. These findings suggest that climate change may have serious implications for earthworm communities and for the functions they provide., Unión Europea. Horizonte 2020, Unión Europea. FP7, Ministerio de Ciencia e Innovación (MICCIN), sDiv [Synthesis Centre of the German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Academy of Finland, Natural Sciences and Engineering Research Council of Canada, DOB Ecology, TULIP Laboratory of Excellence, Russian Foundation for Basic Research, Tarbiat Modares University, Aurora Organic Dairy, UGC (NERO), Slovak Research and Development Agency, Science for Global Development through Wageningen University, Norman Borlaug LEAP Programme and International Atomic Energy Agency (IAEA), São Paulo Research Foundation (FAPESP), Oklahoma Agricultural Experiment Station, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Royal Canadian Geographical Society, Environmental Protection Agency (Ireland), University of Hawai‘i at Mānoa, U.S. Department of the Navy, Commander Pacific Fleet, Science and Engineering Research Board, Department of Science and Technology, New Delhi, India, Strategic Environmental Research and Development Program (SERDP) of the U.S. Department of Defense, Maranhão State Research Foundation (FAPEMA), Coordination for the Improvement of Higher Education Personnel (CAPES), Ministry of Education, Youth and Sports of the Czech Republic, Colorado Wheat Research Foundation; Zone Atelier Alpes, French National Research Agency, Austrian Science Fund, Landwirtschaftliche Rentenbank Frankfurt am Main, Welsh Government and the European Agricultural Fund for Rural Development, SÉPAQ, Ministry of Agriculture and Forestry of Finland, Science Foundation Ireland, University of Toronto (Faculty of Forestry), Haliburton Forest and Wildlife Reserve, NKU College of Arts and Sciences, Österreichische Forschungsförderungsgesellschaft, Mountain Agriculture Research Unit of the University of Innsbruck, Higher Education Commission of Pakistan, Kerala Forest Research Institute, Peechi, Kerala, UNEP/GEF/TSBF-CIAT, GRDC, AWI, LWRRDC, DRDC, National Scientific and Technical Research Council (CONICET), National Agency of Scientific and Technological Promotion (FONCyT), Universidad Nacional de Luján/FONCyT, Fonds de recherche sur la nature et les technologies du Québec, Deutsche Forschungsgemeinschaft, CONACYT, NSF, Institute for Environmental Science and Policy at the University of Illinois at Chicago, Dean’s Scholar Program at UIC, Garden Club of America Zone VI Fellowship in Urban Forestry from the Casey Tree Endowment Fund, J. E. Weaver Competitive Grant from the Nebraska Chapter of The Nature Conservancy, College of Liberal Arts and Sciences at DePaul University, Elmore Hadley Award for Research in Ecology and Evolution from the UIC Dept. of Biological Sciences, Comisión Interministerial de Ciencia y Tecnología (CICYT), Yokohama National University, MEXT KAKENHI, Japan Society for the Promotion of Science KAKENHI, ADEME, Syngenta Philippines, UPSTREAM, LTSER, Comisión Europea, National Science and Technology Base Resource Survey Project of China, McKnight Foundation, Program of Fundamental Researches of Presidium of Russian Academy of Sciences, Brazilian National Council of Research CNPq, French Ministry of Foreign and European Affairs, Depto. de Biodiversidad, Ecología y Evolución, Fac. de Ciencias Biológicas, TRUE, pub

We studied the soil community and habitat consequences of introducing a deep-burrowing, sedentary life-style earthworm, Lumbricus terrestris (dew-worm) into arable zero-till clay. Seventeen years after introduction, which was originally aimed at improving the macroporosity and permeability of the heavy clay soil, we returned to the gradient of L. terrestris dispersal (well established, more recent and no settlement) and investigated the temporal development of the ecosystem engineering impacts on different faunal groups (earthworms, enchytraeids and nematodes) and soil porosity. The faunal re- sponses were examined both at L. terrestris midden scale (individual living site) and field scale. We found that L. terrestris middens sustained elevated densities of all three faunal groups. In the case of earth- worms, there was evidence for temporal development of the engineering impact as the difference be- tween the midden and non-midden areas was more pronounced in the well-established areas than close to the leading edge of dispersal. The earthworm community composition was not altered at L. terrestris midden sites. The settlement of L. terrestris had no discernible effects on field-scale earthworm and nematode abundances, but enchytraeids were practically absent beyond the leading edge of the dispersal. This effect might, however, be partly explained by a gradient of increasing clay content. Soil macroporosity at L. terrestris midden sites did not increase with the age of L. terrestris settlement. Our results suggest that L. terrestris settlement in a clay soil can significantly increase the spatial patchiness of soil fauna, but may not, except in the case of enchytraeids, affect their field-scale abundances or the macroporosity of the soil in the vicinity of L. terrestris living sites.

All living organisms modify their biotic and abiotic environment. Niche construction theory posits that organism-mediated modifications to the environment can change selection pressures and influence the evolutionary trajectories of natural populations. While there is broad support for this proposition in general, there is considerable uncertainty about how niche construction is related to other similar concepts in ecology and evolution. Comparative studies dealing with certain aspects of niche construction are increasingly common, but there is a troubling lack of experimental tests of the core concepts of niche construction theory. Here, we propose an operational framework to evaluate comparative and experimental evidence of the evolutionary consequences of niche construction, and suggest how such research can improve our understanding of ecological and evolutionary dynamics in ecosystems. We advocate for a shift toward explicit experimental tests of how organism-mediated environmental change can influence the selection pressures underlying evolutionary responses, as well as targeted field-based comparative research to identify the mode of evolution by niche construction and assess its importance in natural populations.

Soil quality is often used as a qualitative, general term. However, quantification is an important feature of the scientific approach to nature. On the other hand, addressing specific soil parameters as indicators of soil quality includes a reduction of the whole soil system. Therefore, results obtained by specialized methodologies ought to be evaluated by methods integrating the soil characteristics in situ. In this presentation, results are given from an investigation of the tilth of two differently managed loamy soils. One of the soils had been managed for decades with a forage crop system (labeled FCS), which included fertilization with farmyard manure, while the other had been grown with a continuous cereal system (labeled CCS), receiving no input of organic matter. In the field, the structure of the top 30-cm soil layer was described visually (spade analysis) and by studying the fragmentation behavior (soil drop test). Further, the field measurements included determination of soil strength by a torsional shear box method. In the laboratory, shear strength was determined on bulk soil sampled in metal cylinders, and tensile strength was estimated from crushing tests of individual, differently sized aggregates. The FCS soil appeared porous, with crumbs as structural units, while the CCS soil was compact with blocks as structural units. The soil drop test yielded the highest degree of fragmentation for the FCS soil. The torsional shear box method showed the CCS soil to have the highest bulk soil strength. This was confirmed by the laboratory shear annulus method. Finally, the tensile strength measurements revealed a much higher strength of 8-16, 4-8 and 2-4 mm dry aggregates from the CCS soil as compared to the FCS soil, while 1-2 mm aggregates were strongest in the FCS soil. This indicates a higher friability for the FCS soil, which is in accordance with the soil behavior in the field tests. In conclusion, the quality of the FCS soil – as evaluated by its mechani

During the last decades Denmark has experienced a growing interest in low-input farming systems like organic farming. These systems rely on a high soil fertility to maintain nutrient availability and plant health. Soil aggregation contributes to this fertility, because it is crucial to soil porosity, aeration and infiltration of water. This paper reports a study of two pairs of differently managed, neighboring fields. The aim was to elucidate long-term effects of the different farming systems on physical and biological variables with influence on bonding and binding mechanisms of soil aggregation. Each pair consists of an organically grown dairy farm soil, based on a forage crop rotation system, including grass (Org-FCS(G)) and a conventionally managed soil. One of the conventional farms has a forage crop rotation with annual cash crops and no grass (Conv-FCS(NG)) and one has been grown continuously with small grain cereals and rape (Conv-CCS). Our results indicate that the Org-FCS(G) soils stimulate biotic soil aggregating agents as measured by extracellular polysaccharides (EPS) and hyphal length measurements, respectively. Generally, the Conv-CCS soil, which relies exclusively on synthetic fertilisers and cereal production, offered poor conditions for the biotic binding and bonding agents. Nevertheless this soil contained a large amount of stable macro-aggregates. This is explained by the physical results, which indicated that the strong macro-aggregation was due to clay dispersion and cementation processes rather than to biotic processes.