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The invasion of jumping worms, a small group of pheretimoid earthworm species from Asia, has increasingly become an ecological, environmental and conservation issue in forest ecosystems and urban-suburban landscapes around the world. Their presence is often noticed due to their high abundance, distinctive “jumping” behavior, and prominent granular casts on the soil surface. Although they are known to affect soil carbon dynamics and nutrient availability, no single paper has summarized their profound impacts on soil biodiversity, plant community, and animals of all trophic groups that rely on soil and the leaf litter layer for habitat, food, and shelter. In this study, we summarize the biology, invasion, and ecological impacts of invasive jumping worms across North America. We highlight potential impacts of this second wave of earthworm invasion, contrast them with the preceding European earthworm invasion in temperate forests in North America, and identify annual life cycle, reproductive and cocoon survival strategies, casting behavior and co-invasion dynamics as the key factors that contribute to their successful invasion and distinct ecological impacts. We then suggest potential management and control strategies for practitioners and policy makers, underscore the importance of coordinated community science projects in tracking the spread, and identify knowledge gaps that need to be addressed to understand and control the invasion.

Long-term fire exclusion may weaken ecosystem resistance to the return of fire. We investigated how a surface wildfire that occurred after several decades of fire exclusion affected a southern Appalachian forest transitioning from a fire-adapted to a fire-intolerant state. Tree traits associated with fire adaptation often co-occur with traits for nutrient conservation, including the ectomycorrhizal (ECM) association. In the absence of fire, the ECM association may facilitate the accumulation of organic matter, which becomes colonized by fine roots that then become vulnerable to consumption or damage by fire. Therefore, a deeper organic horizon might make stands of fire-adapted, ECM trees less resistant to a surface wildfire than stands of arbuscular mycorrhizal (AM), fire-intolerant trees. To test this hypothesis, we established plots in stands that fall along a gradient of mycorrhizal tree relative abundance both inside and outside the perimeter of the 2016 Rock Mountain wildfire. With increasing relative abundance of ECM trees, we found increasing organic horizon depth and mass and slower rates of decay, even for litter of ECM tree species. We calculated a major (73–83%) reduction in fine root biomass and length in the organic horizon following the wildfire. Over three years post-fire, we observed a higher probability of crown decline, basal sprouting and aboveground biomass mortality with increasing abundance of ECM trees. We propose that the biogeochemistry of mycorrhizal associations can help explain why fire exclusion makes stands of fire-adapted trees less resistant to a surface wildfire than those with fire-intolerant trees.

Two new species of Bimastos Moore are described based on morphological and molecular data. Bimastos nanae n. sp. resembles B. lawrenceae Fender, B. zeteki (Smith and Gittins) and B. welchi (Smith). Bimastos nanae n. sp. differs from these species in the position of the clitellum, size and number and position of thickened septa. Bimastos magnum n. sp. is similar to B. schwerti Csuzdi & Chang and B. palustris Moore in having a fully annular clitellum and male pores on huge porophores. Bimastos magnum n. sp. differs from both species by having a more posterior position of the clitellum (in xxiv-xxxiii, xxxiv) and larger body size. With the description of these new species, the number of Bimastos species is raised to 14.

In this chapter, we describe current understanding of and identify research gaps on how invasive species directly, and indirectly, affect ecosystem processes. Specifically, we focus on how invasive species can alter the terrestrial carbon, nitrogen, and hydrologic cycles and how changes to these terrestrial cycles cascade to affect water quantity and quality. While invasive species may alter other ecosystem processes, we focus on these due to their importance to policy, to the public, and to their likely interaction with climate change effects. For example, carbon sequestration and surface water supply originating from forests and grasslands (Caldwell et al. 2014) are important policy and public concerns, and drought frequency and intensity will likely increase with climate change (Vose et al. 2016a). Our goal is to draw generalizations rather than provide details on invasive species effects on a case-by-case basis. We do, however, provide case studies for illustration and draw linkages with other chapters that provide detailed coverage to disturbance regimes (Chap. 5) and types and mechanisms of ecological impact caused by invasive insects (Chap. 2).

Soil ecology and restoration ecology are offshoots of the broader discipline of ecology and have essentially developed and operated as separate subdisciplines. Although restoration ecologists have long appreciated soils as important to the practice of restoring ecosystems, there has been relatively little overlap between the disciplines apart from straightforward single-factor manipulations (e.g., addition of organic matter), and application of soil microbial inoculations. Here, we not only briefly review some of these soil microbial manipulations but also focus on several other components of soil ecological systems, with emphasis on soil fauna. Expanding the soil ecological context to include fauna in restoration science is needed because these organisms are known to influence soil physical and chemical attributes, as well as the functions of soil microbes. In spite of their demonstrated influences on ecological processes, the soil fauna are usually considered in terms of their responses to restorative treatments, and not as agents of restoration themselves. The fauna that engage in ecological engineering (i.e., those that move large quantities of soil and provide habitat for other organisms) are of particular importance in the development of soil profiles, small-scale heterogeneity, and ecosystem function, but these are rarely considered in restoration projects. The group consists of a myriad of invertebrate and vertebrate animals including earthworms, ants, termites, mammals, and reptiles (among others). Detailed knowledge of these different fauna is required for application to restoration scenarios because not all engineering taxa are equivalent, and some are not appropriate, as some nonnative engineers can cause damage to ecosystems. Thus we hope to inspire dialog among all disciplines with interests in ecosystem restoration, to further the ultimate goal of producing fully functional, diverse, and resilient restored ecosystems.

Much of the literature dealing with the biology and management of invasive species has focused on the damaging ecological and economic consequences of invasions (see Chaps. 2, 3, and 14 of this volume for review). In this chapter, we shift the focus to the causes of invasion, with the goal of proactively limiting or preventing invasions rather than reacting to them once they have occurred. Preventing the introduction of invasive species is one key element in this proactive approach (Chap. 6, this volume). Here, we specifically focus on ecosystem attributes that affect whether or not an ecosystem is vulnerable to invasion, that is, the features that affect its invasibility (Lonsdale 1999), with particular emphasis on the role of natural and anthropogenic disturbance.

Soils are natural bodies, formed by the state factors of physical, chemical, and biological processes operating on geologic parent material over time. Long recognized for their importance to agriculture and forestry, the role of soils in natural systems has been underappreciated. Soils provide important ecosystem services, determined by their natural capital, a function of texture, mineralogy, and organic matter. Our conceptual model for examining soil and landscape restoration is based on the state factors; their interaction produces a mosaic of microhabitats across the landscape. Interest in soil restoration is embedded within a variety of international policy initiatives; forest restoration in particular enjoys much international support since the inception of the Bonn Challenge in 2011. Objectives for soil restoration aim to recover functions by reversing degradation and returning soils to healthy conditions, but the widespread human footprint cannot be ignored. The starting point for restoration can be approached by answering two questions: “Do we have it? and Do we want it?”. This leads to four possible strategies: preserving or eliminating current conditions, or achieving or avoiding some future conditions. Historic examples of large-scale restoration in Northeastern and Southeastern United States, Puerto Rico, Denmark, and South Korea illustrate different trajectories following abandonment of agriculture and recovery of forest vegetation. One critical factor was how much previous land use degraded the soils. Future conditions are likely to differ from current and recent historical conditions due to climate change. Climate change has a significant impact on soils, including decoupling important soil–vegetation linkages resulting in accelerated wind and water erosion. The need today is great for restoring landscapes, with a special focus on stabilization and improvement of their underlying soils, and this need likely will become even greater over the next decades.

Invasive earthworms in North America are known to have dramatic influences on soil ecosystems, including negative effects on other soil fauna. In general, studies examining this phenomenon have focused on invasive earthworm impacts on organisms at the same or lower trophic level as the earthworms themselves (i.e., detritivores and decomposers). In contrast, there have been relatively few studies of invasive earthworm impacts on higher trophic levels or food web interactions. Invasive earthworms might alter food webs either directly as prey items, or indirectly through their profound alteration of soil physical characteristics, which might in turn alter established predator/prey interactions. In this study, we created experimental mesocosms to investigate the influence of an invasive earthworm on a native predator-prey interaction. We incubated several combinations of a widespread Asian invasive earthworm (Amynthas agrestis), a generalist centipede predator (family: Cryptopidae), and a putative microarthropod prey species (Sinella curviseta) in an experiment to determine their interactions. We hypothesized that collembolan abundance would be reduced in mesocosms containing centipedes. We further hypothesized that earthworm feeding on litter substrate in the mesocosms would reduce the complexity of the substrate, and thus increase the likelihood of centipede/collembolan encounters, with the ultimate effect of more pronounced reduction of Collembola populations in mesocosms containing both earthworms and centipedes. Unexpectedly, we found that earthworms had a negative effect on collembolan abundance early in the incubation and that centipedes did not. Collembolan populations were less variable through time in the presence of earthworms, suggesting that invasive earthworms exerted some regulatory pressure on food or habitat supply for the collembolans. Centipedes lost biomass when only Collembola were available for food, but gained biomass when incubated with earthworms. We noted a simultaneous significant decrease in earthworm biomass (mainly in the form of earthworm mortality) in experimental units that contained centipedes relative to those without centipedes. Taken together, these results suggest that this invasive earthworm may represent a novel prey resource for the centipedes, and that their presence in ecosystems could have consequences on both higher and lower trophic levels.

Environmental disturbances seem to be increasing in frequency and impact, yet we have little understanding of the belowground impacts of these events. Soil fauna, while widely acknowledged to be important drivers of biogeochemical function, soil structure and sustainability, and trophic interactions, are understudied compared to other belowground organisms such as archaea, bacteria, and fungi. In this review we summarize the current state of knowledge of soil fauna as it relates to and is influenced by various disturbances. We focus our review on three main natural and anthropogenic disturbance types: 1) natural disturbances, including damage from wind and flooding; 2) invasive species, including above and belowground flora and fauna; and 3) climate change impacts on the atmosphere and temperature. We do not address the impacts of wildfires, forestry, agricultural practices, mining, or human-caused pollution, as these topics have all been covered in other works. We highlight knowledge gaps and suggest future avenues of research, with hope that the importance of soil fauna and their influences on ecosystems will be given greater emphasis in future research.

Regardless of how soil is defined, soils are the most diverse of all ecosystems. It is estimated that 25–30% of all species on Earth live in soils for all or part of their lives (Decaens et al. 2006). A single gram of soil is estimated to contain 1 × 109 microorganisms, roughly the same population size as the number of humans in Africa (Microbiology by Numbers 2011). That same gram of soil likely contains 4000 species. They are only one part of a larger food web, however, that includes roundworms (phylum Nematoda), springtails (order Collembola), and other fauna (Fig. 5.1). The soil fauna has equally astounding numbers (e.g., 40,000 springtails in 1 m2). Soil organisms, ranging from microbes to moles (family Talpidae), promote crop growth and livestock production (Barrios 2007; Kibblewhite et al. 2008), produce antibiotics (Wall et al. 2015), control nutrient loads in surface soils and groundwater (De Vries et al. 2011), and regulate greenhouse gas emissions (Singh et al. 2010).

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., 677232 to N.E.). K.S.R. and W.H.v.d.P. were supported by ERC-ADV grant 323020 to W.H.v.d.P. Also supported by iDiv (DFG FZT118) Flexpool proposal 34600850 (C.A.G. and N.E.); the Academy of Finland (285882) and the Natural Sciences and Engineering Research Council of Canada (postdoctoral fellowship and RGPIN-2019-05758) (E.K.C.); DOB Ecology (T.W.C., J.v.d.H., and D.R.); ERC-AdG 694368 (M.R.); and the TULIP Laboratory of Excellence (ANR-10-LABX-41) (M.L.). In addition, data collection was funded by the Russian Foundation for Basic Research (12-04-01538-a, 12-04-01734-a, 14-44-03666-r_center_a, 15-29-02724-ofi_m, 16-04-01878-a 19-05-00245); Tarbiat Modares University; Aurora Organic Dairy; UGC(NERO) (F. 1-6/Acctt./NERO/2007-08/1485); Natural Sciences and Engineering Research Council (RGPIN-2017-05391); Slovak Research and Development Agency (APVV-0098-12); Science for Global Development through Wageningen University; Norman Borlaug LEAP Programme and International Atomic Energy Agency (IAEA); São Paulo Research Foundation - FAPESP (12/22510-8); Oklahoma Agricultural Experiment Station; INIA - Spanish Agency (SUM 2006-00012-00-0); Royal Canadian Geographical Society; Environmental Protection Agency (Ireland) (2005-S-LS-8); University of Hawai‘i at Mānoa (HAW01127H; HAW01123M); European Union FP7 (FunDivEurope, 265171); U.S. Department of the Navy, Commander Pacific Fleet (W9126G-13-2-0047); Science and Engineering Research Board (SB/SO/AS-030/2013) Department of Science and Technology, New Delhi, India; Strategic Environmental Research and Development Program (SERDP) of the U.S. Department of Defense (RC-1542); Maranhão State Research Foundation (FAPEMA); Coordination for the Improvement of Higher Education Personnel (CAPES); Ministry of Education, Youth and Sports of the Czech Republic (LTT17033); Colorado Wheat Research Foundation; Zone Atelier Alpes, French National Research Agency (ANR-11-BSV7-020-01, ANR-09-STRA-02-01, ANR 06 BIODIV 009-01); Austrian Science Fund (P16027, T441); Landwirtschaftliche Rentenbank Frankfurt am Main; Welsh Government and the European Agricultural Fund for Rural Development (Project Ref. A AAB 62 03 qA731606); SÉPAQ; Ministry of Agriculture and Forestry of Finland; Science Foundation Ireland (EEB0061); University of Toronto (Faculty of Forestry); National Science and Engineering Research Council of Canada; Haliburton Forest and Wildlife Reserve; NKU College of Arts and Sciences Grant; Österreichische Forschungsförderungsgesellschaft (837393 and 837426); Mountain Agriculture Research Unit of the University of Innsbruck; Higher Education Commission of Pakistan; Kerala Forest Research Institute, Peechi, Kerala; UNEP/GEF/TSBF-CIAT Project on Conservation and Sustainable Management of Belowground Biodiversity; Ministry of Agriculture and Forestry of Finland; Complutense University of Madrid/European Union FP7 project BioBio (FPU UCM 613520); GRDC; AWI; LWRRDC; DRDC; CONICET (National Scientific and Technical Research Council) and FONCyT (National Agency of Scientific and Technological Promotion) (PICT, PAE, PIP), Universidad Nacional de Luján y FONCyT [PICT 2293 (2006)], Fonds de recherche sur la nature et les technologies du Québec (131894), Deutsche Forschungsgemeinschaft [SCHR1000/3-1, SCHR1000/6-1, 6-2 (FOR 1598), WO 670/7-1, WO 670/7-2, and SCHA 1719/1-2], CONACYT (FONDOS MIXTOS TABASCO/PROYECTO11316); NSF (DGE-0549245, DGE-0549245, DEB-BE-0909452, NSF1241932); 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; the 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; Spanish CICYT (AMB96-1161; REN2000-0783/GLO; REN2003-05553/GLO; REN2003-03989/GLO; CGL2007-60661/BOS); Yokohama National University; MEXT KAKENHI (25220104); Japan Society for the Promotion of Science KAKENHI (25281053, 17KT0074, 25252026); ADEME (0775C0035); Ministry of Science, Innovation and Universities of Spain (CGL2017-86926-P); Syngenta Philippines; UPSTREAM; LTSER (Val Mazia/Matschertal); Marie Sklodowska Curie Postdoctoral Fellowship (747607); National Science and Technology Base Resource Survey Project of China (2018FY100306); McKnight Foundation (14-168); Program of Fundamental Researches of Presidium of Russian Academy of Sciences (AAAA-A18-118021490070-5); Brazilian National Council of Research CNPq; and French Ministry of Foreign and European Affairs. Author contributions: H.R.P.P. led the analysis, data curation, and writing of the original manuscript draft. C.A.G. assisted in analyses and writing of the original manuscript draft. E.K.C. and N.E. revised subsequent manuscript drafts. J.v.d.H., D.R., and T.W.C. provided additional analyses. E.K.C., N.E., and M.P.T. acquired funding for the project. J.K., K.B.G., B.S., M.L.C.B., M.J.I.B., and G.B. contributed to data curation. H.R.P.P., C.A.G., M.L.C.B., M.J.I.B., G.B., O.F., A.O., E.M.B., J.B., U.B., T.D., F.T.d.V., B.K.-R., M.L., J.M., C.M., W.H.v.d.P., K.S.R., M.C.R., D.R., M.R., M.P.T., D.H.W., D.A.W., E.K.C., and N.E. contributed to the project conceptualization. All authors reviewed and edited the final draft manuscript. The majority of the authors provided data for the analyses. Competing interests: The authors declare no competing interests. Data and materials availability: Data and analysis code are available on the iDiv Data repository (DOI: 10.25829/idiv.1804-5-2593) and GitHub (https://github.com/helenphillips/GlobalEWDiversity; DOI: 10.5281/zenodo.3386456).

Earthworm introductions and invasions are ongoing, with significant consequences for ecological characteristics and function where populations of invasive species reach high densities. In North America the influx of people, goods and materials to coastal cities has long been recognized to be related to introduction and establishment of many different invasive organisms. We conducted surveys for soil invertebrates in the Washington, DC area along the Potomac River corridor to examine the influence of historic soil profile disrupting disturbances on the composition of soil invertebrate communities. Here we report three earthworm taxa that either (1) had never been previously reported in North America (Lumbricidae: Helodrilus oculatus), (2) had never been reported from “wild” caught samples in forested soils (Lumbricidae: Eisenia fetida), or (3) represented a notable range expansion for an introduced species (Lumbricidae: Murchieona muldali). All three species reported here have attributes that give reason for concern over their expansion into North American soils, not least of which is their potential for competitive interactions with the remaining native earthworm species.

Within the temperate, deciduous forests of the eastern US, diverse soil-fauna communities are structured by a combination of environmental gradients and interactions with other biota. The introduction of non-native soil taxa has altered communities and soil processes, and adds another degree of variability to these systems. We sampled soil macroinvertebrate abundance from forested sites in Missouri (MO), Michigan (MI), Massachusetts (MA), and New Hampshire (NH), with the objective of comparing community assemblages and evaluating the role of invasive earthworms along the temperature—productivity gradient represented by the sites. The primary detritivores encountered were earthworms and millipedes. Earthworms were collected only in MO and MI, and at much greater density in MO. Millipedes were found at every site except in MO, and at their highest mean density in NH. Warmer temperatures, higher litter productivity, and low Oa horizon depth (as found in MO) were correlated with high earthworm activi...

Peregrine pheretimoid earthworms, commonly known as jumping worms, are members of the family Megascolecidae that have become widely established outside of their native ranges. In many parts of the world this represents a second wave of earthworm invasions, following the introduction of peregrine European earthworms in the family Lumbricidae during the colonial era. Forest ecologists, turf managers, gardeners, and other land managers are concerned about the observed or presumed negative effects of jumping worms on invaded habitats. Although research on jumping worms has accelerated in recent decades, our understanding of their ecology remains limited. We compiled techniques useful to researchers working to fill voids in our understanding. Similar past efforts have focused on tools used to study common European species. Differences in life cycle, behavior, morphology, and physiology make it difficult to transfer experiences with European earthworms to pheretimoids. For example, the loss of reproductive features in many pheretimoid populations poses a challenge for identification, and techniques for individually tagging lumbricid earthworms have been less successful for megascolecids. The active and ongoing expansion of pheretimoid populations in many areas requires increased attention on distributed methods, such as citizen-science protocols, for detecting and tracking their expansion. Finally, the desire to limit populations of pheretimoids, including those invading gardens and other environments that might be successfully restored, has exposed the lack of options for targeted, effective control of unwanted earthworms. We identify opportunities to address these voids in our methodological tool kit and encourage the adaptation of techniques previously used in the study and management of other invasive animals.

Soil fauna are important contributors to ecosystem functioning as well as being tremendously diverse. Effects of warming on soil fauna are understudied and complex, with multiple covariates and a mixture of direct and indirect effects. This, combined with diverse communities, results in a suite of potential responses across temporal, spatial, and biological scales. We present a conceptual diagram to relate these interacting effects and a framework for organizing and understanding past and future research in this field. Themes common in the literature include species-specificity, site-specificity, and the challenge of disentangling the connection between temperature and moisture in soils. Much extant soil biodiversity remains undiscovered and our understanding of the current roles of soil fauna in ecosystem processes is incomplete; future research needs include a focus on these issues as well as using multivariate techniques to separate multiple interacting effects from potentially covarying factors.

Human history is intricately linked to the soil. As human populations increased agricultural land use intensified. Wood availability was also important and resulted in the management of forested land for fuel, fiber and food. Soil mapping was an essential tool in planning future expansion of agriculture and resulted in an increased understanding in the factors that regulate soil formation. This understanding eventually lead to the formation of forest soil science as a separate area of research. Early forest soil research focused on silviculture, harvesting, soil chemistry and acid rain. As the science progressed areas of research broadened to include specialized forest harvest methods and eventually to ecosystem-related research designed to understand how soils function as an integral part of the forest.

Prescribed fire is an important management tool to reduce fuel loads, to remove non-fire adapted species and to sustain fire-adapted taxa in many forested ecosystems of the southeastern USA. Yet, the long-term effects of recurring prescribed fires on soil fungi and their communities in these ecosystems remain unclear. We Illumina MiSeq sequenced and analyzed fungal Internal Transcribed Spacer (ITS2) amplicons from a long-term prescribed burn experiment that has implemented different regimes for nearly a quarter century to evaluate the effects of differing prescribed fire intervals and the season of their implementation on soil-inhabiting fungal communities. Unburned plots were used as a reference to represent the compositional state resulting from fire suppression. Our data show that while the recurring burning or the season of the prescribed burning do not affect richness and diversity of the fungal communities, the frequent (two and three year interval) fires maintain a fire-adapted community that is distinct from those in unburned reference plots. Subsequent indicator taxon analyses identified a total of 37 Operational Taxonomic Units (OTUs) that were more frequent in the frequently implemented burns and 26 OTUs that were more frequent in the fire suppressed treatment. We conclude that frequent prescribed burning maintains fire selected soil fungal communities that may support plant communities that are composed of desired fire adapted or fire tolerant species that dominate the frequently burned areas.

Rare taxa overwhelm metabarcoding data generated using next-generation sequencing (NGS). Low frequency Operational Taxonomic Units (OTUs) may be artifacts generated by PCR-amplification errors resulting from polymerase mispairing. We analyzed two Internal Transcribed Spacer 2 (ITS2) MiSeq libraries generated with proofreading (ThermoScientific Phusion ® ) and non-proofreading (ThermoScientific Phire ® ) polymerases from the same MiSeq reaction, the same samples, using the same DNA tags, and with two different clustering methods to evaluate the effect of polymerase and clustering tool choices on the estimates of richness, diversity and community composition. Our data show that, while the overall communities are comparable, OTU richness is exaggerated by the use of the non-proofreading polymerase–up to 15 % depending on the clustering method, and on the threshold of low frequency OTU removal. The overestimation of richness also consistently led to underestimation of community evenness, a result of increase in the low frequency OTUs. Stringent thresholds of eliminating the rare reads remedy this issue; exclusion of reads that occurred ≤10 times reduced overestimated OTU numbers to

Biological invasions are one of the most significant global-scale problems caused by human activities. Earthworms function as ecosystem engineers in soil ecosystems because their feeding and burrowing activities fundamentally change the physical and biological characteristics of the soils they inhabit. As a result of this “engineering,” earthworm invasions can have significant effects on soil physical, chemical and biological properties. The species Amynthas agrestis (family Megascolecidae) was introduced to the United States from Asia, and has expanded its distribution range to include relatively undisturbed forests. Here, to clarify life history traits, we reared individuals under seven different conditions of food provision using litter, fragmented litter and soil, and also analyzed the stable isotope ratios of field-collected specimens to investigate their food resources in the field. Second, we examined whether prescribed fire can be used to manage invasive earthworms. We constructed eight experimental plots, each with 100 individuals of A. agrestis each, and burned half of the plots. The feeding experiment showed that the earthworms in units containing soil and some form of organic matter (litter and/or fragmented litter) produced many cocoons, indicating that litter and fragmented litter are important food resources for them. Stable isotope analyses also supported this result. During the experimental fires, average soil temperature at 5 cm depth increased by only 7.7 °C (average maximum of 32.2 °C). Litter mass was significantly reduced by the fires. Although numbers of A. agrestis and cocoons recovered from burned and unburned plots were not different, the viability of cocoons was significantly lower in burned plots. Fire may also reduce the survival rate of juveniles in the next year by depriving them of their preferred food resource. Most native earthworms in the United States live in the soil, while many invasive ones live in the litter layer and soil surface. Therefore, prescribed fire could be a viable tool for control of invasive earthworms without negatively impacting native earthworm populations.

We set the stage by giving four main reasons to study soils: (1) humanity depends upon soils for their livelihood and ecosystem services; (2) as a last frontier in biodiversity research, soils teem with common and rare organisms; (3) soils are an excellent medium to study ecology ranging from organisms to ecosystems and entire regions; (4) more importantly, soils are exciting, challenging, and fun!

Terrestrial ecosystems are globally under threat of loss or degradation. To compensate for the impacts incurred by loss and/or degradation, efforts to restore ecosystems are being undertaken. These efforts often focus on restoring the aboveground plant community with the expectation that the belowground microbial community will follow suit. This 'Field of Dreams' expectation - if you build it, they will come - makes untested assumptions about how microbial communities and their functions will respond to aboveground-focused restoration. To determine if restoration of aboveground plant communities equates to restoration of belowground microbial communities, we assessed the effects of four forest restoration treatments - varying in intensity from unmanaged to interplanting tree species - on microbial (i.e. prokaryotic and fungal) community composition and function (i.e. catabolic profiles and extracellular enzyme activities). Additionally, effects of the restoration treatments were compared to both degraded (i.e. active arable cultivation) and target endpoint communities (i.e. remnant bottomland forest) to determine the trajectory of intensifying aboveground restoration efforts on microbial communities. Approximately 16 years after the initiation of the restoration treatments, prokaryotic and fungal community composition, and microbial function in the four restoration treatments were intermediate to the endpoint communities. Surprisingly, intensification of aboveground restoration efforts led to few differences among the four restoration treatments and increasing intensification did not consistently lead to microbial communities with greater similarity in composition and function to the target remnant forest communities. Together these results suggest that belowground microbial community composition and function will respond little to, or will lag markedly behind, intensifying aboveground restoration efforts. Reliance on a Field of Dreams' approach, even if you build it better, may still lead to belowground microbial communities that remain uncoupled from aboveground communities. Importantly, our findings suggest that restoring aboveground vegetation may not lead to the intended restoration of belowground microbial communities and the ecosystem processes they mediate. USFS Southern Research StationUnited States Department of Agriculture (USDA)United States Forest Service; Yale University We thank Stephen Wood and Evelyn Wenk for field assistance. This project was funded through a cooperative agreement between USFS Southern Research Station and Yale University. Public domain – authored by a U.S. government employee

a b s t r a c t This study investigated the possibility of a facilitative relationship between Chinese privet (Ligustrum sinense) and exotic earthworms, in the southeastern region of the USA. Earthworms and selected soil properties were sampled five years after experimental removal of privet from flood plain forests of the Georgia Piedmont region. The earthworm communities and soil properties were compared between sites with privet, privet removal sites, and reference sites where privet had never established. Results showed that introduced European earthworms (Aporrectodea caliginosa, Lumbricus rubellus, and Octolasion tyr- taeum) were more prevalent under privet cover, and privet removal reduced their relative abundance (from >90% to ∼70%) in the community. Conversely, the relative abundance of native species (Diplocardia michaelsenii) increased fourfold with privet removal and was highest in reference sites. Soils under privet were characterized by significantly higher pH relative to reference plots and privet removal facilitated a significant reduction in pH. These results suggest that privet-mediated effects on soil pH may confer a competitive advantage to European lumbricid earthworms. Furthermore, removal of the invasive shrub appears to reverse the changes in soil pH, and may allow for recovery of native earthworm fauna. Published by Elsevier B.V.

Sanjiang Plain is the largest concentrated area of freshwater wetlands in China, however nearly 80% of these freshwater wetlands were drained or reclaimed in the past 50 years. It is important to know whether wetlands reclamation would affect soil invertebrates, especially the winter-active invertebrates. During November 2011 to April 2012, we used pitfall traps and in-field direct observation methods to study the activity of collembolans in wetland, and a reclaimed forest plantation and soybean field. In total, 3465 collembolans were captured and identified to 8 species from 6 families. Desoria sp. 1, Desoria sp. 2 and Desoria sp. 3 were the three dominant species. Collembolan abundance and assemblages were significantly affected by the land use changes. The results showed that (1) Collembola captured by pitfall traps showed a highest abundance in wetland, with ∼50% decreased abundance in soybean field, and ∼75% decreased in the forest plantation. (2) Collembola activity changed during the winter season, their activity significantly increased from early winter to late winter; with a peak in March in all three land use types. (3) Collembola assemblages were affected by land use changes with a significant decrease of frequency of Desoria sp. 3 and a significant increase of frequency of Desoria sp. 2 in soybean field and forest plantation. (4) Collembolan densities on the snow surface usually peaked between 1400 h and 1500 h, and decreased quickly when the temperature dropped below freezing. Mean abundance reached 119 individuals m −2 on the snow surface in wetland, 152 individuals m −2 in soybean field, and 64 individuals m −2 in forest plantation. All collembolans moved up and down through the snow profile depending on temperature, no collembolans were found on the snow surface in the evening. Our study indicated that the reclamation of wetland resulted in a significant decrease of abundance and a different assemblage of winter active Collembola in Northeast China, but land use changes did not change their pattern of activity: Collembolans were rarely active in early and middle winter and mostly active in late winter. Their daily densities on the snow surface fluctuated according to both air temperatures and land use types.

Invasive Asian earthworms are increasingly common in the eastern USA where they are a major cause of terrestrial ecosystem disturbance. Among these, Amynthas agrestis (Crazy Worm, Alabama Jumper, and other common names) has been shown to alter above- and belowground food webs. Life-history traits of these earthworms are largely unknown, particularly in their invaded range. Here, we sought to answer questions about temperature effects on hatching success for cocoons of this species, using specimens collected from the southern Appalachian Mountains. We conducted 2 experiments investigating the effects of incubation temperature and the effect of varying the duration of cold temperature on hatching success. Of the temperatures tested, we found that cocoons hatched with greatest success at 10 °C, but our tests indicate a long duration at that temperature may be needed to result in an increase in hatching success. These results indicate that temperature and the duration of temperature exposure affect hatching success in this species. While our results contribute to the growing body of knowledge about the life-history traits of invasive Asian earthworms in the eastern US, more research is needed to provide a finer-resolution understanding of the optimum level and duration of temperatures for hatching success of A. agrestis.

Over 1100 species of oligochaetes are known from Latin America (LA), of which most are earthworms. Enchytraeid research is not so well developed, mainly due to their small size, the difficulty of identification, and the general ignorance of LA scientists of this family. Some countries, such as Brazil, Colombia and Mexico have active taxonomists, and hence tend to have better knowledge of oligochaete diversity and ecology. However, the few professionals active in the area and a major taxonomic impediment have greatly hindered research on oligochaetes in LA. Four Latin American Meetings on Oligochaete Ecology and Taxonomy (ELAETAO) have been held since 2003. These meetings brought together researchers, students and technicians from 15 countries and resulted in several landmark publications (3 special journal issues and one book) that synthesize research performed in the Americas. Topics addressed include the diversity and distribution of native and exotic earthworm species in all LA countries, the use of oligochaetes as bioindicators, oligochaete genetics and phylogeny, various aspects of vermiculture, earthworm and enchytraeid sampling methods, and ecology and biology of invasive species, among others. Furthermore, since the first ELAETAO, regular training in terrestrial oligochaete ecology and taxonomy (10 earthworm and 2 enchytraeid short courses), as well as in ecotoxicology and molecular genetics has been offered to ∼150 scientists and students in these topics in order to build capacity for research activity. The ELAETAOs have greatly stimulated earthworm and enchytraeid research in LA, but several challenges must still be overcome to adequately assess the true nature of oligochaete biodiversity and their ecology in the region.

The invasive non-native earthworm Amynthas agrestis (Goto and Hatai, 1899) has recently been documented invading forests of the Appalachian Mountains in the southeastern United States. This epigeic earthworm decreases the depth of organic soil horizons, and this may play a role in the decrease of millipede richness and abundance associated with A. agrestis invasion. To investigate the mechanisms behind these effects, A. agrestis and the millipede Sigmoria ainsliei (Xystodesmidae) were placed into microcosms with soil and either L horizon, F and H horizon, or a combination L/FH treatment. Microcosms were destructively sampled and reconstructed with the same treatments every four weeks to assess faunal fresh weight change and survival. Soils from earthworm treatments were wet-sieved for cocoons to assess treatment effects on reproduction. On average, millipede mortality occurred 88 days sooner in treatments that did not have FH horizon material, and within all litter treatments millipedes tended to survive longer when A. agrestis was absent. Earthworms maintained higher fresh weight in L/FH than FH or L treatments. With a single exception, no A. agrestis cocoons were recovered from microcosms that also contained S. ainsliei . The results suggest that A. agrestis and S. ainsliei may compete for food resources, particularly the smaller particle material in the FH horizons of the forest floor. Millipedes may exert some biotic resistance to A. agrestis invasion, as diminished earthworm fecundity was observed in experimental units containing both species.

The largest breeding colony of Manx shearwaters (Puffinus puffinus) in the world is found on the Isle of Rum in the inner Hebrides of Scotland. We collected a feather, guano, soil, vegetation, and earthworms near shearwater burrows to determine whether inputs of nitrogen (N) from guano were incorporated into belowground foodwebs. For comparison, similar samples were collected from a nearby plot that was experimentally fertilised 40 years prior. The shearwater feather had the highest level of 15N enrichment (+18‰), followed by guano (+12‰). Soil (+7.5‰) and vegetation (+5.7‰) collected at the burrow entrance were enriched with 15N relative to those collected at 2 m or more away (+0.5 to +3.1‰ for soil, and −2.5 to −4.6‰ for vegetation). In contrast, soil inside the fertilised plot had δ15N ≈ 0, but was enriched with 15N away from the plot edge. Earthworms collected from shearwater greens had enriched 15N signatures relative to earthworms from the fertilised plot (+3.8 and −0.9‰, respectively). Our data suggest that available N is tightly cycled in vegetation and soil for decades, and that shearwater derived N is substantially assimilated by earthworms. Therefore, because earthworms do not occur outside areas of shearwater influence, the birds should be viewed as ecosystem engineers of soil invertebrate foodwebs on Rum.

Forest soils represent a significant pool for carbon sequestration and storage, but the factors con- trolling soil carbon cycling are not well constrained. We compared soil carbon dynamics at five broadleaf forests in the Eastern US that vary in climate, soil type, and soil ecology: two sites at the University of Michigan Biological Station (MI-Coarse, sandy; MI-Fine, loamy); Bartlett Experimental Forest (NH-BF); Harvard Forest (MA-HF); and Baskett Wildlife Recreation and Educa- tion Area (MO-OZ). We quantified soil carbon stocks and measured bulk soil radiocarbon to at least 60 cm depth. We determined surface (0-15 cm) soil carbon distribution and turnover times in free light (unpro- tected), occluded light (intra-aggregate), and dense (mineral-associated) soil fractions. Total soil carbon stocks ranged from 55 ± 4t o 229± 42 Mg C ha -1 and were lowest at MI-Coarse and MO-OZ and highest at MI-Fine and NH-BF. Differences in climate only partly explained differences in soil organic matter 14 C and mean turnover times, which were 75-260 year for free-light fractions, 70-625 year for occluded-light fractions, and 90-480 year for dense fractions. Turn- over times were shortest at the warmest site, but longest at the northeastern sites (NH-BF and MA-HF), rather than the coldest sites (MI-Coarse and MI-Fine). Soil texture, mineralogy, drainage, and macrofaunal activity may be at least as important as climate in determining soil carbon dynamics in temperate broadleaf forests.

European and Asian earthworm invasions are widespread in North America. European earthworms especially are well-known to cause dramatic changes in ecosystems in northern, formerly glaciated portions of the continent, but less is known about the impacts of earthworm invasions in unglaciated areas inhabited by indigenous earthworms. We monitored fluctuations in the spatial extent of an Amynthas agrestis (Megascolecidae) population in the Great Smoky Mountains National Park in eastern Tennessee, USA. Two years of monthly growing-season observations revealed that the distribution of the earthworm population was dynamic, but overall distribution was closely linked to temperature and moisture with dramatic reductions of earthworm numbers associated with very dry conditions. In plots where A. agrestis were more often detected, we measured increased A-horizon soil aggregation and decreased thickness of the Oe/Oa-horizon. However, A. agrestis was not related to A-horizon microbial biomass, A-horizon C:N, Oi-horizon (litter) thickness, or mass of forest floor (O-horizon). Reductions in millipede species richness and density were associated with frequency of A. agrestis presence, possibly due to direct competition for food resources (Oe/Oa material). This evidence for potentially negative interactions between millipedes and A. agrestis suggests that expansion of the non-native earthworm into new habitats in the Park may alter soil physical properties and could pose a threat to native millipede diversity.

Plant-derived carbon compounds enter soils in a number of forms; two of the most abundant being leaf litter and rhizodeposition. Our knowledge concerning the predominant controls on the cycling of leaf litter far outweighs that for rhizodeposition even though the constituents of rhizodeposits includes a cocktail of low molecular weight organic compounds which represent a rapidly cycling source of carbon, readily available to soil microbes. We determined the mineralization dynamics of a major rhizodeposit, glucose, and its relationship to land-use, microbial community and edaphic characteristics across a landscape in the southeastern United States. The landscape consists of cultivated, pasture, pine plantation, and hardwood forest sites (n ¼ 3). Mineralization dynamics were resolved in both winter and summer using an in situ 13 C-glucose pulse-chase approach. Mineralization rates of the labeled glucose decline exponentially across the 72 h measurement periods. This pattern and absolute mineralization rates are consistent across seasons. An information-theoretic approach reveals that land-use is a moderately strong predictor of cumulative glucose mineralization. Measures assessing the size, activity, and/or composition of the microbial community were poor predictors of glucose mineralization. The strongest predictor of glucose mineralization was soil-extractable phosphorus. It was positively related to glucose mineralization across seasons and explained 60% and 48% of variation in cumulative glucose mineralization in the summer and winter, respectively. We discuss potential mechanisms underlying the relationship between soil phosphorus and glucose mineralization. Our results suggest that specific soil characteristics often related to land-use and/or land-management decisions may be strong predictors of glucose mineralization rates across a landscape. We emphasize the need for future research into the role of soil phosphorus availability and land-use history in determining soil organic carbon dynamics.

Soil biota drive fundamental ecosystem processes such as decomposition, nutrient cycling, and maintenance of soil structure. They are especially active in grassland ecosystems such as the tallgrass prairie, where much of the net primary productivity is allocated belowground and ultimately processed by heterotrophic soil organisms. Because both soil microbes and soil fauna display perturbation responses that integrate the physical, chemical, and biological changes to their environment, the structure of belowground microbial and faunal communities is used widely as an indication of the ecological status of soils. To investigate the effects of military training on tallgrass prairie soil communities, a replicated small-plot study of tracked vehicle disturbance effects was initiated at Fort Riley, Kansas in 2003. This article reports subsequent rates of recovery for soil microbial and invertebrate communities over a range of disturbances encompassing different soil types (silty clay loam and silt loam soils), environmental conditions (wet vs. dry traffic events), traffic intensities (single vs. repeated traffic), and track areas (curve vs. straightaway). Microbial biomass in wet silty clay loam soil treatments and on curve areas in silt loam soil was suppressed for 1–2 years following disturbance but increased to levels greater than undisturbed plots in all treatments by the fourth year. Nematode abundance, family richness, trophic composition, and community structure also displayed maximum disturbance for wet treatments and curve areas. Trophic composition and community structure continued to exhibit disturbance effects throughout the 4-year study period, even after recovery of nematode abundance. Earthworm abundance displayed the most severe reductions (78% across soil types, treatments and areas) immediately following tank traffic but, like microbial biomass, subsequently increased to levels greater than undisturbed plots. Nematode community structure provided a reliable and comprehensive assessment of the status of the soil food web and was an effective bioindicator of ecosystem recovery following traffic disturbance. In addition, given the dominant role of earthworms in ecosystem processes and their extreme sensitivity to tracked vehicle disturbance, it is recommended that this group be included in monitoring protocols for military training land managers.

Management practices, such as fire and mowing, can affect the distribution and quality of roots and soil C and N in grasslands. We examined long-term (13 years) effects of annual fire and mowing on fine (