Elimination of top predators has allowed large herbivores to flourish in many terrestrial ecosystems, transforming food webs and ecosystem functions. Restoration of large predator communities is hoped to reverse negative effects of this trophic downgrading, but evidence for such effects is elusive. Wolves were extirpated in northern Wisconsin but returned via natural dispersal in the 1970s. We use spatially explicit information about wolf range expansion and plant community data collected in the 1950s and again in the early 2000s to assess whether wolves initiated a trophic cascade. We evaluated the hypothesis that the return of wolves benefits native plant species by protecting them from excessive deer browse. Surprisingly, understory plant diversity, richness, and frequency decreased more in areas with longer wolf presence, providing no evidence that wolves have the ability to protect forest understory vegetation. Instead, the data suggest a bottom-up process: deer occupy areas where their preferred food plants are abundant, and wolves follow deer. Wolves do not appear to have the often anticipated ability to down-regulate large deer populations or their browsing pressure to function as biodiversity guardians.

Coastal wetlands within Apostle Islands National Lakeshore (APIS) represent important reference ecosystems for Lake Superior given their relatively undegraded condition. However, this region lacks climate change-relevant nearshore bathymetric information for coastal wetlands, a gap our study helps fill. Since 2010, the Great Lakes, including Lake Superior, have experienced both extended low water levels and extreme highs. Such extremes are anticipated to increase in frequency and duration, but the exact outcomes are uncertain. Therefore, it is important to explore the resiliency of APIS wetlands against different water level scenarios. We studied seven wetlands with different geomorphic connections to Lake Superior (open, transient, or semi-permanent) and gathered water level and depth data. Using depth measurements, we created topo-bathymetric maps to investigate inundation patterns for various scenarios of Lake Superior water levels. Comparing wetland water levels to those of Lake Superior we found that water level patterns were unique per connection type, but that Lake Superior maintained baseline-water levels for all sites. Additionally, the wetlands we sampled demonstrated resiliency to substantial changes in water levels thanks to both bathymetry deeper than record low Lake Superior levels and sufficient undisturbed upslope habitats. However, the biotic communities within could shift in composition depending on future water level regimes. The increasing magnitude and frequency of Great Lakes water level fluctuations induced by climate change will influence all APIS coastal wetlands, regardless of connection type.

As the field of ecology evolves, analyses synthesizing trends in key topics addressed over the decades can provide historical context for the development of novel theories and methods, identify “hot topics” over time, and guide future research directions. Such syntheses in a field that aims to diversify can also help quantify efforts to increase representation and authorship by underrepresented groups in STEM. To identify hot topics in ecology, we analyzed key themes in the top-cited ecology papers in three two-decade timeframes spanning 1960–2019. We also analyzed authorship trends (gender identity and nationality) in the top-cited papers. We documented a shift from descriptive studies in single biological systems in the 1960–1970, to more synthesis-based papers and studies discussing human impacts on the environment in the 1980–1990, while the 2000s were dominated by novel quantitative and macroecological approaches. The top-cited papers were overwhelmingly from the United States and Europe, highlighting the need to make studies from across the globe more visible and accessible in the ecological literature. Finally, we detected a trend for more papers led by women authors, but a decline in papers with women last authors, indicating a need to retain women in leadership positions. Overall, our hot topics analysis highlights the expanding breadth and quantitative nature of ecology, but illustrates barriers to diversity in the perspectives represented in the top-cited papers.

Bumble bee conservation focuses on supplementing floral resources. Yet, nesting site availability is linked to bumble bee abundance. As a supplement to natural nest sites, nest boxes could be deployed and baited with synthetic lures. As queen bumble bees reportedly establish colonies in abandoned rodent burrows, we hypothesized (1) that queen bumble bees sense, and behaviourally respond to, rodent odour, and (2) that lures of synthetic rodent odour can guide spring queens to nest boxes. We collected headspace odorants from bedding soiled with urine and faeces of house mice, Mus musculus , and identified the 10 odorants that elicited responses from queen antennae. To field‐test attraction of queens to mouse excreta odorants, we tree‐mounted paired nest boxes in florally rich locations, and assigned clean and soiled bedding, respectively, to one box in each pair. Queens established colonies in 17 mouse‐scented boxes and in six unscented boxes. This 43% occupancy rate of mouse‐scented boxes represents a significant improvement over the 10% occupancy rate common for unscented boxes. In a further field experiment, we baited one box in each pair with a synthetic mouse odour lure and found that queens established colonies in 13 baited boxes and in six unbaited control boxes. Specifically, Bombus mixtus established seven colonies in baited boxes and only one colony in an unbaited box. With this proof‐of‐concept that synthetic lures can guide queens to nest boxes, we anticipate that bumble bee conservation programs will soon be able to offer both expanded floral resources and baited nest boxes readily detectable by queens.

Aim Environmental conditions strongly affect the distribution and abundance of species via complex forces. Shifts in environmental conditions and differences in the speed and scale of these effects complicate our efforts to infer how species will respond to future environmental change. We test how 18 functional traits affect plant species responses to gradients in environmental conditions and 50-year shifts in climate. Location We analyzed 50-year shifts in the distribution and abundance of 153 plant species distributed across 284 sites in Wisconsin, USA. Time period 1950s to 2000s. Major taxa studied Vascular plants (much of the flora of NE North America). Methods We used random forest and integrated hierarchical mixed models to test how plant abundances (and 50-year changes in abundance) track gradients in overstory, soil, and climatic conditions. Results Within study periods, plant abundances reflect gradients in environmental conditions. Leaf traits affected local abundance (both directly and via trait-environment interactions) in the 1950s and 2000s. Strong soil and temperature effects in the 1950s have weakened while precipitation effects have strengthened. Although we expected these models to also predict how plants would respond to shifts in climate, they did not. Main conclusions Lags in species’ responses, increases in the stochastic forces affecting community assembly, and other forces limit the ability of models fitted to static data (e.g., space-for-time substitutions) to predict how plant species will respond to long-term shifts in environmental conditions. We must therefore be cautious about applying trait-based species distribution models to predict how climate change will affect species distributions and community structure.

Invasive cattails (Typha angustifolia and Typha × glauca) pose a problem for many Laurentian Great Lakes wetlands, especially sedge/grass meadows. In western Lake Superior, early signs of invasion into sedge-dominated peatlands along the Kakagon and Bad Rivers, owned and managed by the Bad River Band of Lake Superior Chippewa, were noticed in the early 1990s. In 1998, we began tracking expansion of Typha patches and assessing causes and ramifications. Perimeters of patches were delineated with GPS, with repeat delineations in 2005 and 2013. At the Kakagon site, permanent transects were established tangential to the 1998 patch perimeters and perpendicular to those transects, extending into the cattails and outward into sedges. Plant communities were sampled along transects in all years. Transects across stands of non-invasive Typha latifolia were sampled for comparisons but showed little change. In 2005, area encompassed by the Kakagon River patches increased by 66

Biotic homogenisation is defined as decreasing dissimilarity among ecological assemblages sampled within a given spatial area over time. Biotic differentiation, in turn, is defined as increasing dissimilarity over time. Overall, changes in the spatial dissimilarities among assemblages (termed 'beta diversity') is an increasingly recognised feature of broader biodiversity change in the Anthropocene. Empirical evidence of biotic homogenisation and biotic differentiation remains scattered across different ecosystems. Most meta-analyses quantify the prevalence and direction of change in beta diversity, rather than attempting to identify underlying ecological drivers of such changes. By conceptualising the mechanisms that contribute to decreasing or increasing dissimilarity in the composition of ecological assemblages across space, environmental managers and conservation practitioners can make informed decisions about what interventions may be required to sustain biodiversity and can predict potential biodiversity outcomes of future disturbances. We systematically reviewed and synthesised published empirical evidence for ecological drivers of biotic homogenisation and differentiation across terrestrial, marine, and freshwater realms to derive conceptual models that explain changes in spatial beta diversity. We pursued five key themes in our review: (i) temporal environmental change; (ii) disturbance regime; (iii) connectivity alteration and species redistribution; (iv) habitat change; and (v) biotic and trophic interactions. Our first conceptual model highlights how biotic homogenisation and differentiation can occur as a function of changes in local (alpha) diversity or regional (gamma) diversity, independently of species invasions and losses due to changes in species occurrence among assemblages. Second, the direction and magnitude of change in beta diversity depends on the interaction between spatial variation (patchiness) and temporal variation (synchronicity) of disturbance events. Third, in the context of connectivity and species redistribution, divergent beta diversity outcomes occur as different species have different dispersal characteristics, and the magnitude of beta diversity change associated with species invasions also depends strongly on alpha and gamma diversity prior to species invasion. Fourth, beta diversity is positively linked with spatial environmental variability, such that biotic homogenisation and differentiation occur when environmental heterogeneity decreases or increases, respectively. Fifth, species interactions can influence beta diversity via habitat modification, disease, consumption (trophic dynamics), competition, and by altering ecosystem productivity. Our synthesis highlights the multitude of mechanisms that cause assemblages to be more or less spatially similar in composition (taxonomically, functionally, phylogenetically) through time. We consider that future studies should aim to enhance our collective understanding of ecological systems by clarifying the underlying mechanisms driving homogenisation or differentiation, rather than focusing only on reporting the prevalence and direction of change in beta diversity, per se.

PremiseNumerous processes influence plant distributions and co-occurrence patterns, including ecological sorting, limiting similarity, and stochastic effects. To discriminate among these processes and determine the spatial scales at which they operate, we investigated how functional traits and phylogenetic relatedness influence the distribution of temperate forest herbs. MethodsWe surveyed understory plant communities across 257 forest stands in Wisconsin and Michigan (USA) and applied Bayesian phylogenetic linear mixed-effects models (PGLMMs) to quantify how functional traits and phylogenetic relatedness influence the environmental distribution of 139 herbaceous plant species along broad edaphic, climatic, and light gradients. These models also allowed us to test how functional and phylogenetic similarity affect species co-occurrence within microsites. ResultsLeaf height, specific leaf area, and seed mass all influenced individualistic plant distributions along landscape-scale gradients in soil texture, soil fertility, light availability, and climate. In contrast, phylogenetic relationships did not consistently predict species-environment relationships. Neither functionally similar nor phylogenetically related herbs segregated among microsites within forest stands. ConclusionsTrait-mediated ecological sorting appears to drive temperate-forest community assembly, generating individualistic plant distributions along regional environmental gradients. This finding links classic studies in plant ecology and prior research in plant physiological ecology to current trait-based approaches in community ecology. However, our results fail to support the common assumption that limiting similarity governs local plant co-occurrences. Strong ecological sorting among forest stands coupled with stochastic fine-scale interactions among species appear to weaken deterministic, niche-based assembly processes at local scales.

Coastal dune habitats such as those of the Apostle Islands National Lakeshore (APIS) are regionally rare habitats of global and state-wide concern. Their dynamic, sandy landforms provide habitat for unique species specifically adapted to frequent disturbance, drought, and other stresses. Despite having disturbance-driven life histories, these species are at risk due to increased visitor use of sandscape habitats and environmental change. Resource managers at APIS have long understood the values of these sandscapes and threats presented by recreational trampling, but more recently they have recognized the precarious position that these coastal habitats are in due to their proximity to the lake and exposure to weather-related phenomena linked with long-term climate change. In recognition of emerging threats and the need to track impacts of these threats, park managers initiated a revision of their methods for monitoring sandscape vegetation. We applied these methods to 15 sandscape locations within the national lakeshore in 2014. Here, we outline what these revisions to the methods were, assess the current status of sandscape structure and composition, assess the utility of data collected with these methods, provide suggestions for further revisions of the sampling method, outline a two-tiered sampling approach for future monitoring, and we provide management recommendations. In a second section of the report, we provide a focused assessment of the size and health of Juniperus communis (common juniper), a target species of concern in these sandscape communities after it was observed by park managers to be dying or stressed on Michigan Island. Our assessments include the status of J. communis across all sandscapes monitored in 2014, and an analysis of change over time since 2012 in the health of J. communis on Michigan, Outer, and Stockton Islands. We provide evidence of impacts by rodents on foliar dieback, primarily on Michigan Island, and we discuss possible interactions with the non-native pale juniper web-worm (Aethes rutilana) and with climate change.

Datasets associated with Johnson, S.E., Zettlemoyer, M.A. Seed predator preferences are associated with seed traits but an unlikely mechanism of local extinction. Restoration Ecology, https://doi.org/10.1111/rec.13627. See README.docx for details.Seed predator preferences are associated with seed traits but an unlikely mechanism of local extinction - Johnson - - Restoration Ecology - Wiley Online Library

Certain traits, including those that make species more vulnerable to consumption by predators, may make species inherently susceptible to population declines and local species loss (i.e. extirpation). To examine whether small mammal and arthropod granivory is a mechanism of community change via association with extirpation events, we studied seed predation on six phylogenetically paired extirpated and extant species from Kalamazoo, Michigan, using a seed removal experiment in a restored prairie. We also examined differences in granivore preferences for seed traits (seed mass, water content, C:N content) and differences in seed traits between extirpated and extant taxa. Granivory was independent of extirpation status but was affected by seed traits. Small mammals consumed more seeds than arthropods and preferentially consumed large seeds, while arthropods consumed small seeds and those with higher C:N ratios (lower nitrogen content). Extirpated and extant taxa did not differ in seed traits, perhaps explaining why they did not differ in granivory. Granivory was phylogenetically conserved, suggesting that certain plant families are more susceptible to granivores than others. This study indicates that granivory varies across species and seed traits in a prairie restoration, but does not likely influence extirpation in this system. Understanding granivore preferences may help managers predict establishment success for rare or extirpated species with particular traits being introduced into prairie restorations.

Numerous processes influence plant distributions and co-occurrence patterns, including ecological sorting, limiting similarity, and stochastic effects. To discriminate among these processes and determine the spatial scales at which they operate, we investigated how functional traits and phylogenetic relatedness influence the distribution of temperate forest herbs. We surveyed understory plant communities across 257 forest stands in Wisconsin and Michigan (USA) and applied Bayesian phylogenetic linear mixed-effects models (PGLMMs) to quantify how functional traits and phylogenetic relatedness influence the environmental distribution of 139 herbaceous plant species along broad edaphic, climatic, and light gradients. These models also allowed us to test how functional and phylogenetic similarity affect species co-occurrence within microsites. Leaf height, specific leaf area, and seed mass all influenced individualistic plant distributions along landscape-scale gradients in soil texture, soil fertility, light availability, and climate. In contrast, phylogenetic relationships did not consistently predict species-environment relationships. Neither functionally similar nor phylogenetically related herbs segregated among microsites within forest stands. Trait-mediated ecological sorting appears to drive temperate-forest community assembly, generating individualistic plant distributions along regional environmental gradients. This finding links classic studies in plant ecology and prior research in plant physiological ecology to current trait-based approaches in community ecology. However, our results fail to support the common assumption that limiting similarity governs local plant co-occurrences. Strong ecological sorting among forest stands coupled with stochastic fine-scale interactions among species appear to weaken deterministic, niche-based assembly processes at local scales.

Wisconsin's plant communities are responding to shifting disturbance regimes, habitat fragmentation, aerial nitrogen deposition, exotic species invasions, ungulate herbivory, and successional processes. To better understand how plant functional traits mediate species' responses to changing environmental conditions, we collected a large set of functional trait data for vascular plant species occupying Wisconsin forests and grasslands. We used standard protocols to make 76,213 measurements of 34 quantitative traits. These data provide rich information on genome size, physical leaf traits (length, width, circularity, thickness, dry matter content, specific leaf area, etc.), chemical leaf traits (carbon, nitrogen, phosphorus, potassium, calcium, magnesium, ash), life history traits (vegetative and flower heights, seed mass), and traits affecting plant palatability (leaf fiber, fat, and lignin). These trait values derive from replicate measurements on 12+ individuals of each species from multiple sites and 45+ individuals for a selected subset of species. Measurements typically reflect values for individuals although some chemical traits involved composite samples from several individuals at the same site. We also qualitatively characterized each species by plant family, woodiness, functional group, and Raunkiaer lifeform. These data allow us to characterize trait dimensionality, differentiation, and covariation among temperate plant species (e.g., leaf and stem economic syndromes). We can also characterize species' responses to environmental gradients and drivers of ecological change. With survey and resurvey data available from >400 sites in Wisconsin, we can analyze variation in community trait distributions and diversity over time and space. These data therefore allow us to assess how trait divergence vs. convergence affects community assembly and how traits may be related to half-century shifts in the distribution and abundance of these species. The data set can be used for non-commercial purposes. The data set is licensed as follows: CC-By Attribution 4.0 International. We request users cite both the OSF data set and this Ecology data paper publication.

ABSTRACT Despite advances in community assembly theory, uncertainties remain regarding how ecological and evolutionary processes shape species distributions and communities. We analyzed patterns of occurrence for 139 herbaceous plant species across 257 forest stands in Wisconsin (USA) to test predictions from community assembly theory. Specifically, we applied Bayesian phylogenetic linear mixed effects models (PGLMMs) to examine how functional traits and phylogenetic relationships influence plant distributions along environmental gradients and how functional similarity and phylogenetic relatedness affect local species co-occurrence. Leaf height, specific leaf area, and seed mass mediate species distributions along edaphic, climatic, and light gradients. In contrast, functional trait similarity and phylogenetic relationships only weakly affect patterns of local co-occurrence. These results confirm that broad-scale plant distributions are largely shaped by ecological sorting along environmental gradients but suggest deterministic assembly rules based on niche differentiation and complementary resource use may not govern local species co-occurrence in homogeneous environments. Statement of authorship JB conceived the idea for the study. DL, SJ, and DR collected the vegetation and functional trait data. JB analyzed the data with assistance from DL. KC, KS, TG, and DW secured funding for research and oversaw data collection. JB wrote the first draft of the manuscript, all authors contributed to manuscript revisions. Data accessibility statement Upon acceptance, data will be archived at Figshare ( https://figshare.com/ ) and scripts used to analyze the data will be shared on Github ( https://github.com/jaredjbeck/ ).

Aim The relative importance of stochastic and deterministic niche processes can affect the assembly of communities in response to land use context and change. In this study, we quantified the relative importance of dispersal- vs niche-based processes in structuring forest plant metacommunities and sought to understand how these processes have changed in these forests over the past 50 years. Location Wisconsin, USA. Methods We used plant understorey community survey data in both the 1950s and 2000s from 142 upland forest stands in southern and northern Wisconsin forests to relate compositional similarity to geographic and environmental distances among sites (reflecting dispersal and niche-based processes, respectively). We then partitioned the variance to determine their relative importance over time. Finally, we classified species into three dispersal groups based on seed mass, dispersal mode, and plant height to assess how these affect community structure. Results Both niche and dispersal processes influence the structure of Wisconsin's forest plant understories. Niche-based processes related to environmental differences among sites dominate the mostly continuous northern upland forests. In contrast, dispersal processes dominate community assembly in the more fragmented southern upland forests. Dispersal processes increased in importance in both regions and especially in more fragmented southern upland forests over the past 50 years. We detected no differences among dispersal groups in how similarity decays with geographic distance. Conclusions In regions retaining heavy forest cover, niche-based assembly still predominates while in areas with smaller scattered patches of forest, stochastic dispersal plays a greater role. Dispersal-based processes increasingly dominate forest metacommunity dynamics in both regions.

The composition and dominance of 1256 witness (land survey) trees were compiled for the early Colonial era (pre-1700) in two locations in eastern Virginia, a region where studies of such information are lacking. The study locations are the Marine Corps Base Quantico and the Cheatham Annex Naval Supply Center, both along major rivers of Tidewater Virginia. At Quantico, a total of 754 witness trees comprising 22 species were recorded. Oak (Quercus) species made up 67% of these trees, followed by hickory (Catya; 15%), poplar (Liriodendron), guns (Nyssa), and pine (Pinus) each representing 4% of the forest composition. At Cheatham Annex a total of 502 witness trees from 24 species were recorded. Oaks made up 57% of the total composition followed by hickory (13%), pine (10%), poplar (5%), and gum (5%). There was a dearth of late successional, fire sensitive species at both locations, despite the presence of many mesic locations that should support such species. This suggests Native American activity (e.g., burning and land clearing) was an important factor affecting forests in eastern Virginia. This research provides a better understanding of the original forests of eastern Virginia and can serve as a baseline for making comparisons with present day forests to assess forest change since the Colonial era.

In a collaborative effort to advance climate adaptation resources available to wetland practitioners, the Wisconsin Initiative on Climate Change Impacts (WICCI) and the Northern Institute of Applied Climate Science (NIACS) have partnered to create adaptation resources for non-forested wetland management. This effort is also supported by the USDA Northern Forests Climate Hub. This publication provides perspectives, information, resources, and tools to wetland managers and natural resource professionals in the Midwest and Northeast regions of the United States as they endeavor to adapt natural communities and ecosystems to the anticipated effects of climate change. In this publication, we identify potential strategies and approaches that facilitate climate adaptation while meeting wetland conservation or restoration management goals and objectives. Adaptation strategies and approaches are intended to build upon current management actions that work to sustain ecosystems over the long term and support site goals while also adjusting systems to changing conditions. While it is beyond the scope of this publication to comprehensively address all potential adaptation tactics applicable to the conservation of wetlands, we provide examples to guide thinking, recognizing that individual wetland management projects have unique goals. Wetland professionals, reliant on their expertise and judgement, can use the adaptation strategies and approaches presented in this document to develop custom adaptation tactics based on the local conditions

Herbivores can profoundly influence plant species assembly, including plant invasion, and resulting community composition. Population increases of native herbivores, e.g. white-tailed deer (Odocoileus virginianus), combined with burgeoning plant invasions raise concerns for native plant diversity and forest regeneration. While individual researchers typically test for the impact of deer on plant invasion at a few sites, the overarching influence of deer on plant invasion across regional scales is unclear. We tested the effects of deer on the abundance and diversity of introduced and native herbaceous and woody plants across 23 white-tailed deer research sites distributed across the east-central and north-eastern USA and representing a wide range of deer densities and invasive plant abundance and identity. Deer access/exclusion or deer population density did not affect introduced plant richness or community-level abundance. Native and total plant species richness, abundance (cover and stem density) and Shannon diversity were lower in deer-access vs. deer-exclusion plots. Among deer-access plots, native species richness, native and total cover, and Shannon diversity (cover) declined as deer density increased. Deer access increased the proportion of introduced species cover (but not of species richness or stem density). As deer density increased, the proportion of introduced species richness, cover and stem density all increased. Because absolute abundance of introduced plants was unaffected by deer, the increase in proportion of introduced plant abundance is likely an indirect effect of deer reducing native cover. Indicator species analysis revealed that deer access favoured three introduced plant species, including Alliaria petiolata and Microstegium vimineum, as well as four native plant species. In contrast, deer exclusion favoured three introduced plant species, including Lonicera japonica and Rosa multiflora, and 15 native plant species. Overall, native deer reduced community diversity, lowering native plant richness and abundance, and benefited certain invasive plants, suggesting pervasive impacts of this keystone herbivore on plant community composition and ecosystem services in native forests across broad swathes of the eastern USA.