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As we enter the United Nations Decade of Ecosystem Restoration, the need to engage in restoration activities has never been greater. Included within this need is a requirement for clear communication between researchers, practitioners, policymakers, stakeholders, and community members. To facilitate the discussion and assessment of restorative activities, we propose two decision trees to differentiate between key restoration terms (Reclamation, Rehabilitation, Ecological Restoration, Rewilding, Landscape Restoration, Intra-Ecosystem Restoration, Reference Condition Restoration, and Ecological Reclamation) and to clarify how they relate to each other, based upon project scope and desired/intended project outcomes. Continued use of unclear terminology impedes practitioners or researchers from using the literature efficiently, to find precedents that could assist their current efforts. As such, increasing clarity of communications will ensure restoration is discussed within a framework of well-defined and agreed upon terms. It is our hope that this suggested framework will contribute to the ongoing and much needed terminology debate and help enhance cohesion on the use of key terms within the restoration focused literature. Given the increased focus upon restoration projects of any kind, especially during the UN's decade of ecosystem restoration, it is more important than ever that restoration practitioners speak the same language.

Wildlife is declining around the world. Many developed nations have enacted legislation on endangered species protection and provide funding for wildlife recovery. Protecting endangered species is also supported by the public and judiciary. Yet, despite what appear as enabling conditions, wild species continue to decline. Our paper explores pathways to endangered species recovery by analyzing the barriers that have been identified in Canada, the United States, and Australia. We summarize these findings based on Canada’s Species at Risk Conservation Cycle (assessment, protection, recovery planning, implementation, and monitoring and evaluation) and then identify 10 “bridges” that could help overcome these barriers and bend our current trajectory of wildlife loss to recovery. These bridges include ecosystem approaches to recovery, building capacity for community co-governance, linking wildlife recovery to ecosystem services, and improving our storytelling about the loss and recovery of wildlife. The focus of our conclusions is the Canadian setting, but our findings can be applied in other national and subnational settings to reverse the decline of wildlife and halt extinction.

Warming global temperatures are expected to strongly influence plant communities, yet there is limited knowledge of how these changes will interact with stressors such as the invasion of exotic earthworms. We conducted a small-scale microcosm experiment to assess the individual and interactive effects of warming and exotic anecic earthworms (Lumbricus terrestris L.) on the growth of sugar maple (Acer saccharum Marsh.) seedlings. After 50 days, the elevated-temperature chamber created warmer and drier soil conditions and increased several measures of plant growth, including stem width, ratio of stem width to stem height, stem biomass, and fine-root biomass. Earthworms did not have any clear impacts on plant growth on their own nor in interactions with the temperature chambers. However, earthworms both reduced surface leaf litter cover and exposed soils, which could exacerbate evaporative losses and moisture stress in field soils resulting from a warming climate under different growing conditions. Future studies should consider the long-term effects of earthworm–temperature interactions on sugar maple growth, as well as diurnal and seasonal changes in temperature.

Anthropogenic noise is increasing worldwide because of growing human populations, transportation, and resource extraction. This excessive noise negatively impacts humans and wildlife. To mitigate noise pollution, the use of vegetation in urban planning is becoming increasingly common. However, noise attenuation can be influenced by poorly understood differences in land cover and seasonality that exist across complex urban and peri-urban environments. We compared the noise attenuation capacity of sites typifying dominant land covers in southern Ontario, Canada (forest, tallgrass prairie, and agriculture) across three seasons (summer, fall, and winter). We found that total noise attenuation was affected by a complex interaction of both site and season across low (250 Hz), mid (500 Hz), and high (1000 Hz) frequency sound. Seasonal changes in vegetation density varied between sites and seemed to play only a partial role in total noise attenuation. While forest, trees, and shrubs continue to be effective for managing noise pollution, our results suggest that other types of land cover can also be useful (e.g., tallgrass prairie). With growing interest in the potential noise attenuating capabilities of vegetation, we recommend further consideration of the seasonal variation in attenuation that can occur across the diverse land covers of urban and peri-urban environments.

The purpose of our study was to determine whether earthworms facilitate the burial of surface-applied wood ash. We mixed a fluorescent tracer powder with fly ash from a commercial biomass boiler to track and quantify ash burial in microcosms containing different densities of the deep-burrowing anecic earthworm Lumbricus terrestris L. While passive incorporation of the wood ash-tracer mix from the surface in the absence of earthworms was limited (rarely penetrating more than 2 cm below the surface), earthworms increased the amount of ash-tracer found belowground and the maximum depths at which ash-tracer was observed (up to 16 cm deep). We suspect that earthworms facilitated wood ash burial primarily by creating burrows down which wood ash could be carried by water and by burying wood ash-covered leaf litter. Earthworms may help increase the efficacy of wood ash amendment in ecosystems where it is impractical to manually mix amendments into the soil (e.g. forests).

With a growing body of research dedicated to understanding earthworm seed preferences, we conducted a preliminary investigation of two previously unconsidered factors: seed density and previous earthworm egestion. We used no-choice feeding experiments with the common European earthworm Lumbricus terrestris L. and seed of the biennial forb Alliaria petiolata (M. Bieb) Cavara & Grande. Earthworm seed ingestion increased exponentially when available seed density was doubled (+305%) and was reduced when encountering seed that had previously been egested by another earthworm (−30%). Impacts of seed density and previous earthworm egestion have broader ecological implications for earthworm granivory behaviour and earthworm-plant interactions in natural and managed ecosystems. We recommend both factors as promising candidates for future experimentation.

There has been minimal study of how ecosystem engineering anecic earthworms such as Lumbricus terrestris L. may influence the distribution of mulch amendments across the soil surface by collecting residues into middens. The two primary research objectives of this study were: (1) to determine how rapidly earthworms change the surface distribution of mulch following amendment, and (2) to produce a more spatially explicit map of earthworm aggregation of mulch. This study used a microcosm experiment to assess the immediate, short-term impacts of earthworms on recently added mulch at a small scale, and an opportunistic field study of the longer-term impacts of earthworms on the distribution of corn ‘stubble’ mulch in a former agricultural field. In the microcosm experiment, earthworms rapidly redistributed mulch within the first week post amendment, decreasing initial ground cover (15-29% decrease). Over the subsequent five weeks, initial cover continued to decrease (20-45% decrease) as mulch was spread thinly onto adjacent, initially bare soil (49-69% increase). Higher mulch amendment mitigated losses in initial cover. In the field study, earthworms aggregated mulch across the soil surface, collecting 40% of the woody corn residues into 17% of the total area in regularly distributed middens. These results demonstrate the potential for L. terrestris to alter the distribution of mulch rapidly in the first several days and weeks following application and in the longer term over several years, increasing the spatial heterogeneity of soil resources. This physical redistribution has only been minimally investigated and may help inform models of earthworm impacts on various ecological processes and improve soil amendment and residue management in earthworm-occupied soils.

This is the peer reviewed version of the following article: Sutherland, W.J., Alvarez‐Castaneda, S.T., Amano, T., Ambrosini, R., Atkinson, P., Baxter, J.M., Bond, A.L., Boon, P.J., Buchanan, K.L., Barlow, J., Bogliani, G., Bragg, O.M., Burgman, M., Cadotte, M.W., Calver, M., Cooke, S.J., Corlett, R.T., Devictor, V., Ewen, J.G., Fisher, M., Freeman, G., Game, E., Godley, B.J., Gortazar, C., Hartley, I.R., Hawksworth, D.L., Hobson, K.A., Lu, M.‐L., Martin‐Lopez, B., Ma, K., Machado, A., Maes, D., Mangiacotti, M., McCafferty, D.J., Melfi, V., Molur, S., Moore, A.J., Murphy, S.D., Norris, D., van Oudenhoven, A.P., Powers, J., Rees, E.C., Schwartz, M.W., Storch, I. and Wordley, C. (2020), Ensuring tests of conservation interventions build on existing literature. Conservation Biology, 34: 781-783, which has been published in final form at https://doi.org/10.1111/cobi.13555. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving. The attached file is the final approved author manuscript version, you are advised to consult the publisher’s version if you wish to cite from it.

In response to our recent article (Higgs et al. 2018) in these pages, George Gann and his coauthors defended the Society for Ecological Restoration (SER) International Standards, clarified several points, and introduced some new perspectives. We offer this counter-response to address some of these perspectives. More than anything, our aims are in sharpening the field of restoration in a time of rapid scaling-up of interest and effort, and support further constructive dialogue going forward. Our perspective remains that there is an important distinction needed between Standards and Principles that is largely unheeded by Gann et al. (2018). We encourage SER to consider in future iterations of its senior policy document to lean on principles first, and then to issue advice on standards that meet the needs of diverse conditions and social, economic, and political realities.

Although insect defoliators are recognized as major agents of ecological change in North American forests, their ecology in industrially degraded landscapes with poor-quality soils, metal contamination, and marginal vegetation growth is largely unknown. We fed gypsy moth larvae (Lymantria dispar L.) paper birch leaves (Betula papyrifera Marsh) (Fagales: Betulaceae) collected from four forested catchment areas near an abandoned Cu/Ni smelter in Sudbury (Ontario, Canada) with different histories of industrial degradation and remediation (reference, remediated, natural recovery, and degraded). We measured caterpillar feeding, frass properties and decomposability, and the effects of frass on the growth of ticklegrass (Agrostis scabra Willd.) (Poales: Poaceae). Caterpillars generally ate more (+25–50%) and produced more frass (+30–40 %) on a diet of leaves from the more industrially degraded sites. Frass had an overall positive effect on plant survivorship (+4.1–10.8 effect size) and growth (+0.1–0.5 effect size), although the smallest benefits came from frass derived from vegetation from the more heavily degraded sites. Our results suggest that defoliating insects respond to differences in environmental degradation and remediation and that industrial landscapes may be particularly susceptible to more extensive defoliation and increased conversion of foliar biomass into frass, which could alter plant growth and survivorship, soil development, and nutrient and metal cycling. Some of these effects may pose additional challenges to landscape recovery (e.g., increased defoliation) while others may be beneficial (e.g., enhanced plant growth and soil development).

Transport by earthworms contributes to the secondary dispersal of seeds and influences patterns of plant community structure and function. To date, however, research on earthworm seed dispersal has focused primarily on vertical transport and the collection of seeds into middens at the soil surface, with no efforts to map horizontal distribution after burial. This study used an emergence depth assay and depth-stratified seedling emergence from soil microcosm cross-sections to map earthworm seed transport in three dimensions using commercial grass seed and the anecic earthworm Lumbricus terrestris L. While specific seed burial profiles should not be considered representative of burial under field conditions (due primarily to high earthworm densities under artificially limiting microcosm conditions), we created what we believe to be the first three-dimensional and most detailed map of earthworm seed burial, visualizing and quantifying the ability of L. terrestris to redistribute seed both vertically and horizontally throughout the soil profile. L. terrestris buried 6.5 to 17.4% of the total seeds and reduced aboveground grass biomass by 59–65 %. Vertically, L. terrestris buried seeds evenly across the 13 cm deep microcosms. Horizontally, L. terrestris aggregated seeds into small clusters aligned obliquely across soil depths, which suggest seeds being deposited in burrow walls (variance to mean ratio: 3.39 ± 2.49). Seeds were aggregated regardless of L. terrestris density but covered a greater cross-sectional area of the soil profile when more earthworms were present. Spatial patterning of shallow buried seed still capable of emergence is a newly described mechanism by which L. terrestris might influence the spatial structure of plant communities.

Wood ash is produced by burning wood residues for energy and is often landfilled but can be more sustainably used as a forest soil amendment. We investigated how different fly and bottom wood ashes applied at a moderate 10 Mg∙ha−1 (dry) affected earthworms, a key group of forest soil biota. We conducted a field experiment with different wood ashes and application timings to determine the effects on population densities of different earthworm functional groups three weeks and one year post-amendment. We also used three laboratory microcosm experiments focused on the geographically widespread and ecologically influential anecic earthworm Lumbricus terrestris to test how wood ashes affect acute survivorship as well as habitat avoidance and surface feeding behaviors. In the field, wood ash amendment generally decreased or had no impact on earthworm densities in the first three weeks following amendment (with density decreases up to − 52 m−2), but had neutral or minor positive impacts one year later (up to + 21 m−2). In the laboratory, wood ashes generally had no effects on short-term earthworm survivorship or growth, but earthworms did respond behaviorally to certain wood ashes by habitat avoidance and reduced surface activity, with decreases in the overall frequency of aboveground events (−63%), the individual duration of each event (−63%), and the percentage of events that involved contact with litter (−53%). Across all experiments, fly ash tended to have a stronger effect than bottom ash. Overall, our study suggests that while some wood ashes may have limited short-term impacts on earthworm abundances, they may cause more subtle but ecologically important behavioral changes. Additionally, these earthworm-wood ash interactions are likely influenced by highly scenario-specific circumstances, including wood ash type, application site, and timing of application.

Summary Earthworm-seed interactions are increasingly recognized as ecologically important. Efforts to study these interactions make use of either no-choice or choice feeding trials due to logistical constraints or differing objectives, however, evidence is lacking regarding the consistency of feeding preferences by earthworms between these scenarios. We conducted a small-scale study in which we compared ingestion and egestion of eleven seed species by the anecic earthworm Lumbricus terrestris L. between no-choice and choice feeding dish trials. We found that seed ingestion and egestion differed between species and the seed ingestion preferences were relatively consistent (Pearson Correlation, r = 0.695) between the feeding trials. These results indicate that seeds preferred in isolation are similarly detectable and preferred alongside other options, aiding in the interpretation of results of other anecic earthworm-seed feeding experiments and suggesting that L. terrestris has a surprisingly strong ability to discriminate between and selectively consume specific seeds from a larger and diverse pool of species options.

We discuss aspects of one of the most important issues in ecological restoration: how to evaluate restoration success. This rst requires clearly stated and justied restoration goals and targets; this may seem “obvious” but in our experience, this step is often elided. Indicators or proxy variables are the typical vehicle for monitoring; these must be justied in the context of goals and targets and ultimately compared against those to allow for an evaluation of outcome (e.g. success or failure). The monitoring phase is critical in that a project must consider how the monitoring frequency and overall design will allow the postrestoration trajectories of indicators to be analyzed. This allows for real‐time management adjustments—adaptive management (sensu lato)—to be implemented if the trajectories are diverging from the targets. However, as there may be large variation in early postrestoration stages or complicated (nonlinear) trajectory, caution is needed before committing to management adjustments. Ideally, there is not only a goal and target but also a model of the expected trajectory—that only can occur if there are sucient data and enough knowledge about the ecosystem or site being restored. With so many possible decision points, we focus readers' attention on one critical step—how to choose indicators. We distinguish generalizable and specic indicators which can be qualitative, semiquantitative, or quantitative. The generalizable indicators can be used for meta‐analyses. There are many options of indicators but making them more uniform would help mutual comparisons among restoration projects.

A resilient coastal wetland is naturally dynamic and responds to disturbances by maintaining the regimes defining structures and functions. Methods to monitor resilience have been difficult to develop, yet are essential to either prevent or actively navigate a regime shift. As others have reported, ecosystem behavior becomes more variable when resilience decreases and feedbacks begin to weaken. To advance the practice of conservation within protected areas, a resilience-based approach to monitoring was explored within Fathom Five National Marine Park, Canada. By means of a multivariate distance-based control chart, the variability of fish assemblages in eight coastal wetlands over an eight-year period (2005–2012) was monitored. The control chart identified occasions when variance in three of the park's wetlands deviated more than expected (i.e., acted “out of control”). To explain the exceedances. an ordination of fish assemblages was completed using principal components analysis (PCA) and redund...

Conservation zoning is a planning process that has been used within protected areas to spatially establish and communicate conservation goals and reduce user conflicts. Here, we explored a resilience-based approach to zoning in Fathom Five National Marine Park, Lake Huron, Canada, using the decision support tool Marxan with Zones, a command line program that we interfaced with our Geographic Information System (GIS). Conservation features were identified and organized into general themes of ecosystem structure, ecosystem function, and social structure. Target values for these features were set to achieve representativeness, replication, and connectivity goals, while minimizing social, political, and economic costs. Although 100 different near-optimal solutions were generated, we paid particular attention to the “best” and “summed” solutions. Implementation recommendations also included considerations for active learning, adaptive management, and good governance. The tools and methods provide an ...

Management actions concerning free-roaming horses attract controversy in many areas. In the Chilcotin region of British Columbia, Canada, social and cultural values influence debates about management of free-roaming horses and perceptions of their ecological impacts. A dearth of current, empirical research on the role and impacts of horses in local ecosystems results in management decisions being informed largely by studies from other ecoregions and locations, which may not accurately represent local ecological, social, cultural, and economic influences. We initiated the first socio-ecological study of horse sub-populations, their grazing habitat, and past management approaches affecting current conditions in the ?Elegesi Qayuse Wild Horse Preserve in Xeni Gwet'in (Tsilhqot'in) First Nations' territory. This exploratory study used mixed methods including a review of literature and unpublished data, assessment of vegetation in core grazing habitat, and exploration of local ecological and cultural knowledge and perceptions. Plant community composition and abundance in core grazing habitat of the Wild Horse Preserve are consistent with a structurally sound ecosystem. Socio-cultural factors are important for managers to consider in effective decision-making concerning horse populations.

The stakes are high as investment commitments to ecological restoration intensify1. The ‘international standards’ published by the Society for Ecological Restoration (SER)2 and the adoption of a narrow definition of restoration by the United Nations Convention to Combat Desertification (UNCCD)3 are indications that restoration is moving away from the open and flexible approach that we believe is needed to address responsible intervention in times of rapid change.

This paper describes iEnvironment, a software platform that supports monitoring and modeling of aspects of surface water. This platform supports surface water science and engineering research, especially when managing and analyzing big and open data. The system will facilitate research collaboration among science and engineering disciplines supported by computer scientists and software developers. In this paper, we briefly describe the iEnvironment architecture, highlighting its reusability and extensibility and some applications.

Plant communities are often seed-limited, and while rodents and birds are considered to be the primary contributors to surface seed removal, there is growing appreciation for the role of soil invertebrates, including earthworms. There have been very few studies assessing the relative importance of earthworms as granivores under field conditions compared to other taxa. We conducted a small-scale experiment in which we used earthworm inoculations and field exclosures to control access to surface-sown grass seed in an open field habitat and monitored impacts on initial grass recruitment. In isolation, earthworms reduced grass recruitment under field conditions (−22% biomass), but their impact was smaller than the reductions that occurred irrespective of earthworm presence when aboveground taxa had access to plots (−80–83%). The results of this small-scale study suggest that although earthworm-seed interactions may be ecologically important overall, in some habitats other taxa may be more influential than earthworms in terms of total surface seed removal.

The reality confronting ecosystem managers today is one of heterogeneous, rapidly transforming landscapes, particularly in the areas more affected by urban and agricultural development. A landscape management framework that incorporates all systems, across the spectrum of degrees of alteration, provides a fuller set of options for how and when to intervene, uses limited resources more effectively, and increases the chances of achieving management goals. That many ecosystems have departed so substantially from their historical tra-jectory that they defy conventional restoration is not in dispute. Acknowledging novel ecosystems need not constitute a threat to existing policy and management approaches. Rather, the development of an integratedapproach to management interventions can provide options that are in tune with the current reality of rapid ecosystem change. Fil: Hobbs, Richard J.. University of Western Australia. School of Plant Biology; Australia Fil: Higgs, Eric. University of Victoria. School of Environmental Studies; Canadá Fil: Hall, Carol M.. University of Victoria. School of Environmental Studies; Canadá Fil: Bridgewater, Peter. Beijing Forestry University. School of Nature Conservation; China Fil: Chapin III, F. Stuart . University of Alaska. Institute of Arctic Biology; Estados Unidos Fil: Ellis, Erle C.. University of Maryland. Geography and Environmental Systems; Estados Unidos Fil: Ewel, John J.. University of Florida. Department of Biology; Estados Unidos Fil: Hallett, Lauren M.. University of California. Department of Environmental Science, Policy and Management; Estados Unidos Fil: Harris, James. Cranfield University. School of Energy, Environment and Agri-Food; Reino Unido Fil: Hulvey, Kristen B.. University of Western Australia. School of Plant Biology; Australia. Utah State University. Department of Wildland Resources and the Ecology Center; Estados Unidos Fil: Jackson, Stephen T.. DOI Southwest Climate Science Center; Estados Unidos Fil: Kennedy, Patricia L.. Oregon State University. Department of Fisheries and Wildlife and Eastern Oregon Agriculture and Natural Resource Program; Estados Unidos Fil: Kueffer, Christoph. Swiss Federal Institute of Technology. Department of Environmental Systems Science. Institute of Integrative Biology; Suiza Fil: Lach, Lori. James Cook University. Centre for Tropical Environmental and Sustainability Science; Australia Fil: Lantz, Trevor C.. University of Victoria. School of Environmental Studies; Canadá Fil: Lugo, Ariel E.. International Institute of Tropical Forestry; Puerto Rico Fil: Mascaro, Joseph. American Association for the Advancement of Science; Estados Unidos Fil: Murphy, Stephen D.. University of Waterloo. Department of Environment and Resource Studies; Canadá Fil: Nelson, Cara R.. University of Montana. College of Forestry and Conservation. Department of Ecosystem and Conservation Sciences; Estados Unidos Fil: Perring, Michael P.. University of Western Australia. School of Plant Biology; Australia Fil: Richardson, David M.. Stellenbosch University. Department of Botany and Zoology. Centre for Invasion Biology; Sudáfrica Fil: Seastedt, Timothy R.. University of Colorado. Department of Ecology and Evolutionary Biology; Estados Unidos Fil: Standish, Rachel J.. University of Western Australia. School of Plant Biology; Australia Fil: Starzomski, Brian M.. University of Victoria. School of Environmental Studies; Canadá Fil: Sudin, Katherine N.. University of California. Department of Environmental Science, Policy and Management; Estados Unidos. University of Colorado. Department of Ecology and Evolutionary Biology; Estados Unidos Fil: Tognetti, Pedro Maximiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Métodos Cuantitativos y Sistemas de Información; Argentina Fil: Yakob, Laith. London School of Hygiene & Tropical Medicine. Department of Disease Control; Reino Unido Fil: Yung, Laurie. University of Montana. College of Forestry and Conservation. Resource Conservation Program; Estados Unidos

The treatment of municipal wastewater can be problematic in the remote cold climate environment of the Canadian Arctic, because of a variety of operational, financial, and technical and bureaucratic reasons. As a result, treatment facilities for many communities are thought to only achieve preliminary to primary treatment of municipal wastewater; wastewater often being discharged directly onto the tundra. In this study we provide the first season long study of tundra wetland systems in the Canadian Arctic. In 2008, we studied the performance of six wetland systems used for wastewater treatment in the Kivalliq Region of Nunavut, Canada. The wetland systems studied services communities of approximately 320–2300 residents, including commercial and government buildings, but generally minimal industry. In total, the systems receive a flow rate of approximately 28–163 m 3 /day of wastewater. We observed average weekly percent reduction in all parameters, with deviations immediately after snow-melt and at the beginning of freeze-up. For the six parameters monitored we observed reductions of 47–94% cBOD 5 , 57–96% COD, 39–98% TSS, >99% TC, >99% E. coli , 84–99% NH 3 -N and 80–99% TP. In three of the systems, the water discharged from the wetlands and into the receiving environment maintained similar concentrations, and significant similarities in NH 3 -N and TP as observed in the natural background concentrations of nearby wetlands. The performance of tundra wetlands to treat the wastewater demonstrates that they are an appropriate technology for remote Canadian Arctic communities. This study also exemplifies the ability of natural systems to act as sinks and transformers, acknowledging that mechanistic assessments will be required to identify primary processes involved in the treatment of Arctic wastewater.

The context for this study is the management concerns over the severity and extent of the impact of cormorants on island flora in the recent past on Lake Erie islands. Accordingly, this study sought to quantify the nesting colonies' influence on coarse woody litter and how nest densities and litter depth may influence the herbaceous layer, the seed bank composition and viability across the extent of three Lake Erie islands. The data for this study were collected from 2004 to 2008 on East Sister Island and Middle Island using two main strategies. First, herbaceous layer surveys, cormorant nest counts, soil seed bank cores, and litter depth measurements were executed using a plotless-point quarter method to test island-wide impacts from nesting activities (data were also collected on a third island, West Sister Island as a reference for the other two islands). Secondly, a sub-sample of the entire plot set was examined in particularly high nesting density areas for two islands (Middle Island and East Sister Island). Kruskal-Wallis tests indicated that there are subtle changes in the herbaceous diversity (total, native and exotic) and seed bank composition across the islands. The sub sample set of the plots demonstrated that Phalacrocorax auritus nest density does influence litter depth, herbaceous species abundance and diversity. Cormorant nesting pressures are restricted to areas of high nesting pressures and competition. However, there remains a risk to the interior herbaceous layer of the island if the effects of nesting pressures at the edges advance inward from this perimeter.

In the energy realm there is a pressing need to make decisions in a complex world characterized by biophysical limits. Exergy has been promoted as a preferred means of characterizing the impacts of resource consumption and waste production for the purpose of improving decision-making. This paper provides a unique and critical analysis of universal and comprehensive formulations of the chemical exergy reference environment, for the purpose of better understanding how exergy can inform decision-making. Four related insights emerged from the analysis, notably: (1) standard and universal chemical exergy reference environments necessarily encounter internal inconsistencies and even contradictions in their very formulations; (2) these inconsistencies are a result of incompatibility between the exergy reference environment and natural environment, and the desire to model the exergy reference environment after the natural environment so as to maintain analytical relevance; (3) the topics for which exergy is most appropriate as an analytical tool are not well served by comprehensive reference environments, and (4) the inconsistencies point to a need for deeper reflection of whether it is appropriate to adopt a thermodynamic frame of analysis for situations whose relevant characteristics are non-thermodynamic (e.g., to characterize scarcity). The use of comprehensive reference environments may lead to incorrect recommendations and ultimately reduce its appeal for informing decision-making. Exergy may better inform decision-making by returning to process dependent reference states that model specific processes and situations for the purpose of engineering optimization.

Use of the terms “wild” and “feral” characterizes ongoing debate over management of free-ranging horses. However, the focus on terminology tends to obscure complex differences in meanings and cultural perception. Examining a case study in the Chilcotin region of British Columbia, we explore how the terms “wild” and “feral” distract from the underlying issues at stake in management of horses and the landscape: different ways of valuing, understanding, and relating to land and animals. To be effective in the long term, and to avoid an unwitting continuation of outdated culturally biased land management practices, future decisions regarding management of lands and free-roaming horses in the Chilcotin would benefit from an integrated process informed by both ecological and socio-cultural information.

Exergy is a thermodynamic concept that has been widely promoted for assessing and improving sustainability, notably in the characterization of resources and wastes. Despite having many notable benefits, exergy is often misused by authors who tend to apply it as an intrinsic characteristic of an object ( i.e. , as a static thermodynamic variable). Using both theoretical and empirical evidence the authors present five key limitations that must be overcome before exergy can be applied to characterize objects: (1) the incompatibility between exergy quality and resource quality ; (2) the inability of exergy to characterize non work-producing resources via the concentration exergy; (3) the constraints placed on the derivation of exergy; (4) problems with the exergy reference environment; and (5) the multiple perspectives applied to exergy analysis. Until the limitations are addressed, exergy should only be used for its original purpose as a decision making tool for engineering systems analysis.

We have observed what appears to be the first significant report of herbivory of a population of Alliaria petiolata (M. Bieb.) Cavara & Grande (Garlic Mustard) in Canada. Ceutorhynchus erysimi Fabr., Plutella xylostella L. (Diamondback Moth), and Philaenus spumarius (Meadow Spittlebug) were identified attacking, and successfully proceeding through different stages of development on A. petiolata. From the field observations, we hypothesize that these species have recognized A. petiolata as a host and therefore may be candidates for the management of the invasive species.

One of the proximate results of forest fragmentation, and a cause of continued microenvironmental change and exacerbation of ecological problems, is increased invasions by weedy plant species. One such example is Alliaria petiolata (Brassicaceae), a serious pest threatening much of eastern North America. Alliaria petiolata impedes mitigation of fragmentation and restoration efforts because it tends to outcompete and possibly extirpate much of the native understory species on localized scales. As part of a strategy to address the problems of fragmented habitats, an experiment was conducted to determine whether Sanguinaria canadensis (Papaveraceae) could outcompete A. petiolata. Using an additive design, I transplanted S. canadensis at densities of 0, 1, 2, 3, 5, 7, 9, 11, 15, and 20 ramets/m2 in 1997 and allowed them to interact with initial A. petiolata densities of 128 seedlings and 31 rosettes/m2. As of 2000, multivariate analyses of variance with repeated measures and simple analyses of variance indicated that initial S. canadensis densities of as little as 5 ramets/m2 suppressed A. petiolata. Initial S. canadensis densities of 9 and 11 ramets/m2 resulted in the lowest numbers of late-spring seedlings, numbers and sizes of year 1 and 2 rosettes, numbers and gross areas of stem leaves, numbers of flowering individuals, number of flowers, number of fruits (siliques), and height at flowering. While it remains to be tested whether this will continue and if the reestablishment of S. canadensis will help reassemble forest ecosystems, the experiments indicated that transplanting S. canadensis was effective at mitigating the spread of A. petiolata.

Invasive species have received considerable attention in recent years, but research has primarily focused on invasive species of natural habitats. Furthermore, cropland weeds have often been viewed as possessing a “general-purpose genotype” and therefore exhibiting relatively static genetics. However, a more current view is that weeds are capable of rapid genetic change, thereby making analysis of their evolutionary ecology a potentially valuable component for the development of sustainable weed management systems. In particular, further analysis of ongoing evolutionary change in cropland weeds is important because (1) most cropland weed species exhibit considerable adaptability, (2) cropland agriculture is continuously changing, and (3) further research on weed adaptability is needed to design cropping systems to address evolutionary change. In this review, we examine the potential of cropland weeds to evolve so as to affect their invasiveness. There is abundant evidence of genetic variation within and among weed populations in traits relevant to invasiveness, including seed germination patterns, life history traits, physiological adaptability and adaptation to disturbance and resource fluctuations. Approximately half of cropland weed species are primarily selfing, and species with a high degree of selfing tend to exhibit homogeneity within populations but divergence among populations. We identified four critical areas for future research: conflicting selection pressures on weeds in agroecosystems, feed-back driven dynamics of human-weed co-evolution, co-evolutionary mechanisms of weed adaptation in conjunction with other weed species or organisms, and the role of weed evolution in the restoration of agroecosystems.

Pollen allelopathy results when pollen releases toxins that inhibit seed germination, seedling emergence, sporophytic growth, or sexual reproduction. Of the six known pollen-allelopathic species, two are crops (timothy and corn and four are weeds (orange hawkweed, parthenium, yellow hawkweed, and yellow-devil hawkweed). Allelopathic pollen in weeds could pose threats to crops, especially if both are wind pollinated. Even if it is the crop that is pollen-allelopathic, other crops could be threatened, or more likely, weeds might adapt to pollen allelopathy and pose a greater problem. Nonetheless, pollen allelopathy could be a useful approach to biological control because allelochemicals are packaged in a natural targeting system (pollen grains) and are biologically active at low doses (

Studies were conducted to develop a model from field and laboratory studies to predict the emergence phenology of Chenopodium album. A mechanistic model to predict the phenology of weed seedling emergence across locations, years, and tillage systems is presented. This was accomplished by the integration of hydrothermal time to describe germination and thermal time to describe shoot elongation. The interaction of soil moisture and temperature in the model was accounted for by the integration of hydrothermal time in algorithms predicting seed germination. Soil temperatures within the weed seed germination zone were predicted by temperature ranges at different depths in the soil. Emergence phenology of C. album seedlings was predicted with greater accuracy under no-till and moldboard plow systems than under a chisel plow system. We attributed this lower accuracy in the chisel plow system to increased heterogeneity in the soil matrix and vertical distribution of the seedbank caused by the chisel plow...

Field testing for pollen allelopathy comprises several approaches. In vitro tests must be done first to establish the existence of a pollen allelopathic effect. The number of pollen grains required to elicit an in vitro pollen allelopathic effect then is compared to observations of the number of pollen grains of pollen allelopathic species adhering to stigmas of heterospecifics. In animal-pollinated species, the amount of potential heterospecifics may first be assessed by observing pollinator behavior, but actual enumeration of grains is necessary. In all species, enumeration of the amount of heterospecific pollen transfer requires that stigmas be clipped before they senescence, carefully preserved in small test tubes, and assessed immediately thereafter with aid of a compound microscope. Stigmas may be examined for relative amounts of allelopathic and conspecific pollen to determine if the number of conspecific pollen tubes declines hyperbolically with increasing amounts of allelopathic pollen. Enumerating the number of heterospecific pollen grains on stigmas is used to support testing of the ecological impact of pollen allelopathy by direct manipulation. In habitats (e.g., old fields surrounded by forest tracts) where atmospheric conditions prevent export or import of other pollen from surrounding areas, the influorescences of a pollen allelopathic species can be clipped within a large area and the subsequent effect on seed set of target species can be assessed. The hypothesis that pollen allelopathy causes an ecological impact (reduced sexual reproductive success) is not rejected under two conditions. An absence of pollen from the allelopathic species must result in an increase in seed set in target species and the amount of pollen transferred from allelopathic species to heterospecifics is similar to that causing in vitro reductions in sexual reproduction in the targets. This experimental approach must be repeated over several sites and years in order to provide an unequivocal test for ecological effects of pollen allelopathy. This methodological approach has allowed me to demonstrate that pollen allelopathy is an important ecological interaction between Hieracium pratense and five sympatric Asteraceae species and between Phleum pratense and three sympatric Poaceae species.

We studied the effect of tillage systems (no-till, chisel, and moldboard plow) and the presence or absence ofZea maysL. (corn) on soil temperature, moisture, and, subsequently, the emergence phenology and density ofChenopodium albumL. (common lambsquarters) at two sites (Elora and Woodstock) from 1993 to 1995. The tillage system affected the phenology ofC. albumseedling emergence only in 1995. In that year, more days were required to reach 80% cumulative seedling emergence in no-till than in the chisel or moldboard plow treatments. The delay in obtaining 80% cumulative emergence was attributed to a dry period from days 159 to 177 at Elora and from days 155 and 176 at Woodstock. The presence or absence of Z.maysdid not affect soil temperatures, soil moisture, orC. albumseedling emergence phenologies.Chenopodium albumseedling density was influenced by tillage and environmental conditions. Large variations in seedling density were attributed to environmental conditions. The presence or absence ofZ. maysdid not affectC. albumseedling density.

Field experiments were conducted from 1995 to 1997 in southern Ontario to determine the influence of tillage and ground cover on the quantity of postdispersal seed predation of common lambsquarters and barnyardgrass. Ground-dwelling invertebrates were the dominant seed predators and were responsible for 80 to 90% of all seeds consumed. Predation was highest in no-till and moldboard-plowed environments (averaging 32% in both) and lowest in chisel-plowed environments (averaging 24%). This indicates that the relationship between the level of disturbance and predation is nonlinear and that other factors, such as the mobility of invertebrates and food availability, may also play important roles in determining the quantity of seed predation. In no-till, the type of crop residue also influenced the quantity of predation, with highest seed predation found in plots with corn residue (averaging 31%) and lowest in those with soybean and wheat residue (24 and 21%, respectively). It is apparent that there is an optimum combination of residue quantity and quality that maximizes the quantity of seed predation. Based on the experimental design used in this study, no feeding preference by seed predators was detected between common lambsquarters and barnyardgrass. Density-dependent feeding, however, was evident for both species. Most biological control efforts have centered around predators with specific feeding habits. We contend that invertebrates with opportunistic feeding strategies that feed on weed seeds may be the most significant broad spectrum and natural form of biological weed control affecting weed population dynamics. Populations of beneficial arthropods should be conserved, and management strategies that augment the size of their natural populations should be encouraged.