Non-native plants have invaded nearly all ecosystems and represent a major component of global ecological change. Plant invasions frequently change the composition and structure of vegetation communities, which can alter animal communities and ecosystem processes. We reviewed 87 articles published in the peer-reviewed literature to evaluate responses of arthropod communities and functional groups to non-native invasive plants. Total abundance of arthropods decreased in 62% of studies and increased in 15%. Taxonomic richness decreased in 48% of studies and increased in 13%. Herbivorous arthropods decreased in response to plant invasions in 48% of studies and increased in 17%, likely due to direct effects of decreased plant diversity. Predaceous arthropods decreased in response to invasive plants in 44% of studies, which may reflect indirect effects due to reductions in prey. Twenty-two percent of studies documented increases in predators, which may reflect changes in vegetation structure that improved mobility, survival, or web-building for these species. Detritivores increased in 67% of studies, likely in response to increased litter and decaying vegetation; no studies documented decreased abundance in this functional group. Although many researchers have examined effects of plant invasions on arthropods, sizeable information gaps remain, specifically regarding how invasive plants influence habitat and dietary requirements. Beyond this, the ability to predict changes in arthropod populations and communities associated with plant invasions could be improved by adopting a more functional and mechanistic approach. Understanding responses of arthropods to invasive plants will critically inform conservation of virtually all biodiversity and ecological processes because so many organisms depend on arthropods as prey or for their functional roles, including pollination, seed dispersal, and decomposition. Given their short generation times and ability to respond rapidly to ecological change, arthropods may be ideal targets for restoration and conservation activities.

1. Surveying wildlife communities provides data for informing conservation and management decisions that affect multiple species. Autonomous recording units (ARUs) can efficiently gather community data for a variety of taxa, but generally require software algorithms to classify each recorded call to a species. Species classification Surveying wildlife communities provides data for informing conservation and management decisions that affect multiple species. Autonomous recording units (ARUs) efficiently gather community data by passively recording animal vocalizations (Gibb, Browning, Glover-Kapfer, & Jones, 2019), generally for multiple time periods ('visits') at each surveyed location ('site'). These data, including counts of call recordings and corresponding species classifications, can be used to investigate various ecological questions and are applicable for surveying multiple taxa (e.g. anurans, bats, birds). However, due to the large volumes of data typically collected, most studies using acoustic surveys require classification software to identify the species of each call recording (Gibb et al., 2019). This automated process includes species classification errors that lead to both false-negative and false-positive detections. For instance, when a species is present, false-negative detections can result from successfully recording its calls but misclassifying them as alternative species. These errors are in addition to false negatives from failing to record any of its calls. False-positive detections at sites where a species is absent are often due to misclassifying recorded calls from another species. Estimating the ecological parameters of interest, while addressing these errors is an important consideration when analysing ARU data. Occupancy models (MacKenzie et al., 2002) are a natural framework for analysing ARU data when visits are summarized to detection/non-detection observations for each species (e.g. Banner et al., 2018; Rodhouse et al., 2019). Originally developed to account for false negatives, standard occupancy models assume that all false positives are removed (MacKenzie et al., 2002). Completely eliminating false positives from ARU data is generally cost prohibitive because it requires manually confirming at least one recording for every visit. False positives are an important source of errors in many

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Acoustic recording units (ARUs) enable geographically extensive surveys of sensitive and elusive species. However, a hidden cost of using ARU data for modeling species occupancy is that prohibitive amounts of human verification may be required to correct species identifications made from automated software. Bat acoustic studies exemplify this challenge because large volumes of echolocation calls could be recorded and automatically classified to species. The standard occupancy model requires aggregating verified recordings to construct confirmed detection/non‐detection datasets. The multistep data processing workflow is not necessarily transparent nor consistent among studies. We share a workflow diagramming strategy that could provide coherency among practitioners. A false‐positive occupancy model is explored that accounts for misclassification errors and enables potential reduction in the number of confirmed detections. Simulations informed by real data were used to evaluate how much confirmation effort could be reduced without sacrificing site occupancy and detection error estimator bias and precision. We found even under a 50% reduction in total confirmation effort, estimator properties were reasonable for our assumed survey design, species‐specific parameter values, and desired precision. For transferability, a fully documented r package, , for implementing a false‐positive occupancy model is provided. Practitioners can apply to optimize their own study design (required sample sizes, number of visits, and confirmation scenarios) for properly implementing a false‐positive occupancy model with bat or other wildlife acoustic data. Additionally, our work highlights the importance of clearly defining research objectives and data processing strategies at the outset to align the study design with desired statistical inferences.

Contrast in vegetation composition and structure between 2 nearby areas of semi-desert grassland, 1 dominated by native grasses (top) and 1 dominated by a nonnative grass, Eragrostis lehmanniana (bottom). Photo by our friend and colleague, Eric Albrecht, who studied songbirds on these grasslands as part of his M.S. degree, and who died in 2004.ABSTRACT Invasions by nonnative plants have changed the structure of many terrestrial ecosystems and altered important ecological processes such as fire, the dominant driver in grassland ecosystems. Reestablishing fire has been proposed as a mechanism to restore dominance of native plants in grasslands invaded by nonnative plants, yet fire may function differently in these altered systems, potentially affecting animals in novel ways. To assess whether invasions by nonnative plants alter the effects of fire on animals, we performed a manipulative experiment in semi-desert grasslands of southeastern Arizona that have been invaded by a perennial, nonnative grass from Africa, Lehmann lovegrass (Eragrostis lehmanniana). We applied fire to 36 of 54 1-ha plots established along an invasion gradient where dominance of E. lehmanniana ranged from 0% to 91% of total live plant biomass. Over the 5-year period from 2000 to 2004, we used mark-recapture methods to assess how population and community attributes of small mammals varied along the gradient of nonnative grass and in response to fire. We quantified changes in presence of 17 species, abundance of 9 species, total abundance of all species combined, species richness, and species composition. Based on 11,226 individual mammals from 24 species, we found that effects of nonnative-grass dominance varied with habitat preferences of each species, resulting in composition of the small-mammal community changing predictably along the invasion gradient. As dominance of nonnative grass increased, presence and abundance of granivorous heteromyids and insectivores (e.g., Chaetodipus, Perognathus, Onychomys; pocket mice and grasshopper mice) decreased, whereas presence and abundance of omnivorous and herbivorous murids (e.g., Reithrodontomys, Sigmodon; harvest mice and cotton rats) increased. Species richness of the small-mammal community averaged 8.4 species per plot and was highest at intermediate levels of nonnative-grass dominance where vegetation heterogeneity was greatest. Abundance of all small mammals combined averaged 26.9 individuals per plot and did not vary appreciably with nonnative-grass dominance. During the 4-to 8-week period immediately after fire, abundance of 6 of the 9 most common species changed, with 5 species decreasing and 1 species increasing on burned plots relative to unburned plots. During this same time period, species richness of small mammals decreased by an average of 3 species (38%) and total abundance of all species combined decreased by an average of 16 individuals (61%) on burned plots relative to unburned plots. Effects of fire on vegetation biomass, on presence of 9 of 17 mammalian species, and on abundance...

The hypothesis that habitat restoration will provide for community reestablishment and the creation of habitat heterogeneity was examined with regards to the herpetofauna of longleaf pine sandhills in northwest Florida. The herpetofaunal response to restoration was examined in fire-suppressed, hardwood-dominated areas treated with (1) spring fire; (2) felling or girdling; or (3) a granular form of the herbicide hexazinone. No-treatment controls were also included. Felling or girdling and herbicide plots were burned for fuel reduction two dormant seasons after initial treatment application. Additionally, data were collected in frequently burned reference sandhills to establish the target condition or restoration goal. Vegetation variables and herpetofaunal capture rates were compared among control and treatment areas. Two similarity indices were utilized to compare treatments and controls with reference sites, to examine restoration success. Restoration treatment effects were observed through reduced hardwood densities. Litter composition varied among control and treatment plots, with leaf litter being highest in areas lacking recent fire. Capture rates of some herpetofaunal species varied significantly among treatment plots. In 1997 similarity indices showed that spring-burned and felling or girdling plots were more similar to the reference sandhills than the other plots. Treated plots were not significantly different from controls in 1998, a year of a severe drought.

Because invasions by nonnative plants alter the structure and composition of native plant communities, invasions can alter the function of ecosystems for animals that depend on plants for food and habitat. We quantified effects of an invasion by a nonnative grass on the insect community in grasslands of southeastern Arizona. We sampled insects on 54 1-ha plots established across a gradient of invasion by Lehmann lovegrass (Eragrostis lehmanniana Nees), a perennial species native to southern Africa. Between 2000 and 2004, we captured 94,209 insects representing 13 orders, 91 families, and 698 morphospecies during 2,997 trap nights. Richness of families, richness of morphospecies, and overall abundance of insects decreased as dominance of nonnative grass increased. With every 100 g/m 2 increase in biomass of nonnative grass, the average number of insect families decreased by 5%, morphospecies decreased by 6%, and overall abundance decreased by 14%. In areas dominated by nonnative grass, 2 of 8 orders and 6 of 27 families of insects were present less frequently and one family was present more frequently; 5 of 8 orders and 6 of 27 families of insects were less abundant and 3 families were more abundant than in areas dominated by native grasses. As a result, this plant invasion altered the structure of the insect community, which has consequences for animals at higher trophic levels and for ecosystem processes, including decomposition and pollination. Because complete eradication of nonnative plants might be possible only rarely, maintaining stands of native vegetation in invaded areas may be an important practical strategy to foster persistence of animals in grasslands invaded by nonnative plants.

Like all grasslands across North America, the distribution of desert grasslands has been reduced markedly, and remnants have been altered extensively by humans. In Arizona, New Mexico, Texas, USA, and in Mexico, desert grasslands have been invaded by dozens of non‐native plants, especially perennial grasses that evolved in arid systems with similar climate and disturbance regimes. In desert grasslands invaded by non‐native plants, biomass, richness, and diversity of native plants typically decrease, whereas plant density, biomass, and litter typically increase. These changes in composition and structure of the plant community affect animals that inhabit grassland ecosystems, with the direction and magnitude of effects reflecting the resource needs of each species, the degree of plant invasion, and the contrast in structure between invading and native plants. When non‐native plants present similar structural cues but provide different levels of resources than native plants, cues that trigger habitat selection by animals may be decoupled from the resources linked evolutionarily to that cue, creating the potential for an ecological trap. Plant invasions also influence the ecological drivers that maintain grasslands in an open condition, which will alter the long‐term dynamics of plant and animal populations. Specifically, by increasing fuel load and continuity, fires in invaded grasslands increase in frequency and intensity relative to those in native grasslands. Although eradication is unlikely once a non‐native plant has naturalized, retaining patches of native vegetation within a matrix of non‐native plants may provide a strategy to reduce effects of plant invasions on wildlife in grasslands. © 2013 The Wildlife Society.