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Phylogenetic diversity (PD), the evolutionary history of the organisms comprising a community, is increasingly recognized as an important driver of ecosystem function. However, biodiversity–ecosystem function experiments have rarely included PD as an a priori treatment. Thus, PD's effects in existing experiments are often confounded by covarying differences in species richness and functional trait diversity (FD). Here we report an experimental demonstration of strong PD effects on grassland primary productivity that are independent of FD, which was separately manipulated, and species richness, which was planted uniformly high to mimic diverse natural grasslands. Partitioning diversity effects demonstrated that higher PD increased complementarity (niche partitioning and/or facilitation) but lowered selection effects (probability of sampling highly productive species). Specifically, for every 5% increase in PD, complementarity increased by 26% on average (±8% SE), while selection effects decreased more modestly (8 ± 16%). PD also shaped productivity through clade‐level effects on functional traits, that is, trait values associated with particular plant families. This clade effect was most pronounced in the Asteraceae (sunflower family), which, in tallgrass prairies, generally comprises tall, high‐biomass species with low phylogenetic distinctiveness. FD also reduced selection effects but did not alter complementarity. Our results show that PD, independent of richness and FD, mediates ecosystem function through contrasting effects on complementarity and selection. This adds to growing evidence that consideration of phylogenetic dimensions of biodiversity can advance ecological understanding and inform conservation and restoration. [ABSTRACT FROM AUTHOR]

Plant biodiversity is often partitioned into taxonomic diversity (species composition and abundance), phylogenetic diversity (breadth of evolutionary lineages) and functional diversity (resource‐use strategies or physical traits). Evaluating the effects and interplay of these dimensions can provide insights into how assembly processes drive compositional changes in plant communities. However, teasing apart the effects of different biodiversity dimensions is challenging in observational studies or retrospective analyses.To evaluate how plant phylogenetic and trait history shape community establishment and turnover in restoration of a species‐rich North American tallgrass prairie, we conducted an experiment with 127 species planted in assemblages representing three levels of phylogenetic diversity (PD) and two of functional trait diversity (FD), holding starting species richness (SR) fixed. We tested whether PD and FD of planted assemblages predicted species diversity, compositional turnover and selection on functional traits.Rank order of initial functional and phylogenetic diversity levels was maintained throughout the experiment, but neither diversity measure correlated positively with species richness by the end of the experiment. Phylogenetic and taxonomic beta diversity increased among all treatments. This increase in compositional beta diversity was associated with directional selection on phylogenetically dispersed functional traits. A set of functional traits associated with competitiveness in tallgrass prairies predicted species' cover for all survey years: stem dry matter content, leaf dry matter content, vegetative height and rhizomatous growth. Although all plots collectively converged on a similar suite of functional traits, functional beta diversity increased among high‐FD plots.Synthesis. Neither higher functional nor phylogenetic diversity maintained higher species richness (SR) over time in our study. Although SR was not maintained, higher levels of PD and FD were. Both types of diversity shaped the rate at which plots changed in composition over time, with high diversity treatment plots increasing in beta diversity. Selection for traits convergent across the tree of life drove phylogenetic and compositional divergence among plots. While optimization of site‐specific functional traits may be most important for maintaining higher SR, our work implies that planting higher initial PD and FD may make grassland restorations more adaptable to site conditions that may be difficult to predict. [ABSTRACT FROM AUTHOR]

To examine the efficacy and safety of corneal cross-linking (CXL) for stabilization of progressive keratoconus. Observer-masked, randomized, controlled, parallel-group superiority trial. Sixty participants 10 to 16 years of age with progressive keratoconus, one eye of each deemed the study eye. The study eye was randomized to either CXL plus standard care or standard care alone, with spectacle or contact lens correction as necessary for vision. The primary outcome was steep keratometry (K2) in the study eye as a measure of the steepness of the cornea at 18 months. Secondary outcomes included keratoconus progression defined as a 1.5-diopter (D) increase in K2, visual acuity, keratoconus apex corneal thickness, and quality of life. Of 60 participants, 30 were randomized to CXL and standard care groups. Of these, 30 patients in the CXL group and 28 patients in the standard care group were analyzed. Mean K2 in the study eye 18 months after randomization was 49.7 D (standard deviation [SD], 3.8 D) in the CXL group and 53.4 D (SD, 5.8 D) in the standard care group. The adjusted mean difference in K2 in the study eye was –3.0 D (95% confidence interval [CI], –4.9 to –1.1 D; P = 0.002), favoring CXL. Adjusted differences between groups in uncorrected and corrected vision favored eyes receiving CXL: –0.31 logarithm of the minimum angle of resolution (logMAR; 95% CI, –0.50 to –0.11 logMAR; P = 0.002) and –0.51 logMAR (95% CI, –1.37 to 0.35 logMAR; P = 0.002). Keratoconus progression in the study eye occurred in 2 patients (7%) randomized to CXL compared with 12 patients (43%) randomized to standard care. The unadjusted odds ratio suggests that on average, patients in the CXL arm had 90% (odds ratio, 0.1; 95% CI, 0.02–0.48; P = 0.004) lower odds of experiencing progression compared with those receiving standard care. CXL arrests progression of keratoconus in the majority of young patients. CXL should be considered as a first-line treatment in progressive disease. If the arrest of keratoconus progression induced by CXL is sustained in longer follow-up, particular benefit may be derived from avoiding a later requirement for contact lens wear or corneal transplantation. [ABSTRACT FROM AUTHOR]

Biological invasions can greatly alter ecological communities, affecting not only the diversity and abundance but also composition of invaded assemblages. This is because invaders' impacts are mediated by characteristics of resident species: some may be highly sensitive to invader impacts while others are unaffected or even facilitated. In some cases, this can result in invasive species promoting further invasions; in particular, herbivory by introduced animals has been shown to disproportionately harm native plants, which can indirectly benefit non‐native plants. Here, we investigated whether such patterns emerged through the effects of an invasive fish species on lake plant communities.Specifically, we tested whether invasion of Minnesota (U.S.A.) lakes by Cyprinus carpio (common carp), an omnivorous, benthivorous fish known to reduce abundance and richness of aquatic plants, differentially affected native versus non‐native plant species. We applied statistical models to a large, long‐term monitoring dataset (206 macrophyte taxa recorded in 913 lakes over a 20‐year time period) to test whether carp altered community composition, to identify which macrophyte species were most sensitive to carp and determine whether species characteristics predicted carp sensitivity, and to characterise consequences of carp invasion on lake‐level vegetation attributes.We found that carp exerted strong selective pressure on community composition. Native macrophytes, those with a more aquatic growth form, and those considered less tolerant of disturbance (i.e. higher coefficients of conservatism) were more sensitive to carp. Conversely, no introduced macrophytes exhibited sensitivity to carp and all had higher probabilities of occurrence as carp abundance increased. The net effect of carp invasion was a shift toward less species‐rich plant communities characterised by more non‐native and disturbance‐tolerant species.These results have several implications for conservation and management. First, they reinforce the need to prevent further spread of carp outside of their native range. Where carp have already established, their control should be incorporated into efforts to restore aquatic vegetation; this may be an essential step for recovering particular plant species of high conservation importance. Furthermore, reducing carp abundance could have ancillary benefits of reducing dominance by invasive plant species. Lastly, where carp cannot be eliminated, managers should target native macrophytes that are relatively tolerant of carp in shoreline plantings and other revegetation efforts. [ABSTRACT FROM AUTHOR]

Recognition of wetland ecosystem services has led to substantial investment in wetland restoration in recent decades. Wetland restorations can be designed to meet numerous goals, among which reestablishing a diverse native wetland plant community is a common aim. In agricultural areas, where previously drained wetland basins can fill with eroded sediment from the surrounding landscape, restoration often includes excavation to expose buried seed banks. The extent to which excavation improves the diversity of wetland plant communities is unclear, particularly in terms of longer‐term outcomes. We examined plant species diversity and community composition in 24 restored agricultural wetlands across west‐central Minnesota, U.S.A. In all study wetlands, hydrology was restored by removing subsurface drainage and plugging drainage ditches, thus reestablishing groundwater connectivity and hydroperiod ("business as usual" treatment). In half of the wetlands, accumulated sediment was removed from the basin and redeposited on the surrounding landscape ("excavated" treatment). Initially, sediment removal significantly decreased invasive species cover, particularly of hybrid cattail (Typha × glauca) and reed canary grass (Phalaris arundinacea), and increased community diversity and evenness. Over time, the effects of sediment removal diminished, and eventually disappeared by approximately 6 years after restoration. While our results demonstrate that sediment removal improves initial restoration outcomes for plant communities, longer‐term benefits require sustained management, such as invasive species control or resetting of basins through additional excavation. [ABSTRACT FROM AUTHOR]

Curlyleaf pondweed (Potamogeton crispus) is one of the most widespread and widely managed aquatic invasive plants in North America. Despite decades of management, the efficacy of long‐term management strategies and the effects of environmental drivers on curlyleaf pondweed populations remain uncertain.To evaluate the effects of management and environmental factors on within‐lake distribution and local density of curlyleaf pondweed, we collated monitoring data from point–intercept surveys collected by a variety of lake managers across Minnesota, U.S.A. Using this dataset, comprising 177 lake‐years of plant data, we examined the influence of herbicide treatment, water clarity, snow depth, and ice cover duration on curlyleaf pondweed distribution and density between 2006 and 2015.We evaluated the effects of herbicides on curlyleaf pondweed at three time points relative to treatment: within year, carryover effects the following year, and cumulative effects over multiple years of treatment. All three temporal measures were associated with significant reductions of curlyleaf pondweed. Additionally, herbicidal management reduced both the density and distribution of curlyleaf pondweed. Given that herbicide management led to reductions that carried over into future years, managers may be able to design multi‐year treatments to reduce total management effort over time.We also found strong effects of environmental conditions on curlyleaf pondweed. Elevated lake productivity and decreased winter snow cover were associated with increased springtime distributions of curlyleaf pondweed, whereas duration of winter ice cover had no influence. The influence of productivity suggests that reductions of this invasive species may be an ancillary benefit of water‐quality improvements that lower lakes' trophic status. Our results also show that decreased winter snow cover, as predicted under climate change, could exacerbate problematic growth of curlyleaf pondweed.Harnessing monitoring data from multiple projects, as this study does, allows for robust inference about environmental and management constraints on macrophytes. Because of environmental and management variability, we suggest that treatment regimens follow an adaptive management cycle, with outcomes of management monitored and evaluated, and strategies updated accordingly. It is also vital to continue monitoring both managed and unmanaged lakes to enable stronger inferences about treatment effectiveness. [ABSTRACT FROM AUTHOR]

Aim: Biotic homogenization (BH), a reduction in the distinctness of species composition between geographically separated ecological communities in a region, is an important but underappreciated potential consequence of biological invasions. While BH theory has always considered invasions, it has generally been in a relatively narrow context that the cosmopolitan nature of invasive species increases BH because of their shared presence across many locations. We sought to evaluate this component of BH as well as broader effects of invasive species on BH through changes in native communities, including overall reductions in species richness or shifts in species composition. Location: Minnesota, USA. Time period: 2002–2014. Major taxa studied: Aquatic macrophytes, including both vascular plants and attached macroalgae. Methods: We used surveys of aquatic macrophyte communities from 1,102 shallow lakes in Minnesota, USA (including 248 lakes with repeated surveys) to evaluate relationships between invasion, native species and BH. Results: We found that the presence of invasive species was associated with BH and that this pattern was reflected in both the total community (i.e., with invasive species included) and in the composition of the native species community alone. We found that invaded lakes were more compositionally similar to each other than uninvaded lakes, but that both groups were becoming more similar over time—despite neither group exhibiting declines in species richness. This pattern was largely driven by shifts in the native community itself, with common species becoming more widespread and rare species becoming rarer. Main conclusions: Invasive species increase measures of community similarity through their own presence in multiple locations, and also by influencing the composition of native species. These patterns have important implications for conservation and management and suggest that BH should be considered more widely in evaluating the impacts of biological invasions and developing response strategies. [ABSTRACT FROM AUTHOR]

Nitellopsis obtusa (starry stonewort) is a green macroalga (family Characeae) native to Europe and Asia that is of conservation concern in its native range but expanding in North America. We synthesize current science on N. obtusa and identify key knowledge gaps. Nitellopsis obtusa is able to reproduce sexually or asexually via fragments and bulbils. Native populations reproduce primarily asexually; sexual fertility increases with longer growing seasons and in shallower waters. In North America, only males have been observed. Nitellopsis obtusa has been known from North America for four decades and confirmed in seven U.S. states and two Canadian provinces. It is typically associated with low-flow areas of lakes with alkaline to neutral pH and elevated conductivity. Nitellopsis obtusa has ecological benefits in its native range, contributing to food webs and water clarity. In its invaded range, N. obtusa could negatively influence native macrophytes and habitat quality, but there has been little research on impacts. There have been many efforts to control N. obtusa through physical removal or chemical treatments, but little systematic evaluation of outcomes. Substantial areas of uncertainty regarding N. obtusa include controls on reproduction, full distribution in North America, ecological impacts, and control strategies. [ABSTRACT FROM AUTHOR]

Abstract: Pollinator conservation is of increasing interest in the light of managed honeybee (Apis mellifera) declines, and declines in some species of wild bees. Much work has gone into understanding the effects of habitat enhancements in agricultural systems on wild bee abundance, richness and pollination services. However, the effects of ecological restoration targeting “natural” ecological endpoints (e.g. restoring former agricultural fields to historic vegetation types or improving degraded natural lands) on wild bees have received relatively little attention, despite their potential importance for countering habitat loss. We conducted a meta‐analysis to evaluate the effects of ecological restoration on wild bee abundance and richness, focusing on unmanaged bee communities in lands restored and managed to increase habitat availability and quality. Specifically, we assessed bee abundance and/or richness across studies comparing restored vs. unrestored treatments and studies investigating effects of specific habitat restoration techniques, such as burning, grazing, invasive plant removal and seeding. We analysed 28 studies that met our selection criteria: these represented 11 habitat types and 7 restoration techniques. Nearly all restorations associated with these studies were performed without explicit consideration of habitat needs for bees or other pollinators. The majority of restorations targeted plant community goals, which could potentially have ancillary benefits for bees. Restoration had overall positive effects on wild bee abundance and richness across multiple habitat types. Specific restoration actions, tested independently, also tended to have positive effects on wild bee richness and abundance. Synthesis and applications. We found strong evidence that ecological restoration advances wild bee conservation. This is important given that habitat loss is recognized as a leading factor in pollinator decline. Pollinator responses to land management are rarely evaluated in non‐agricultural settings and so support for wild bees may be an underappreciated benefit of botanically focused management. Future restoration projects that explicitly consider the needs of wild bees could be more effective at providing nesting, foraging and other habitat resources. We encourage land managers to design and evaluate restoration projects with the habitat needs of wild bee species in mind. [ABSTRACT FROM AUTHOR]

Ex situ conservation in germplasm and living collections is a major focus of global plant conservation strategies. Prioritizing species for ex situ collection is a necessary component of this effort for which sound strategies are needed. Phylogenetic considerations can play an important role in prioritization. Collections that are more phylogenetically diverse are likely to encompass more ecological and trait variation, and thus provide stronger conservation insurance and richer resources for future restoration efforts. However, phylogenetic criteria need to be weighed against other, potentially competing objectives. We used ex situ collection and threat rank data for North American angiosperms to investigate gaps in ex situ coverage and phylogenetic diversity of collections and to develop a flexible framework for prioritizing species across multiple objectives. We found that ex situ coverage of 18,766 North American angiosperm taxa was low with respect to the most vulnerable taxa: just 43% of vulnerable to critically imperiled taxa were in ex situ collections, far short of a year-2020 goal of 75%. In addition, species held in ex situ collections were phylogenetically clustered (P < 0.001), i.e., collections comprised less phylogenetic diversity than would be expected had species been drawn at random. These patterns support incorporating phylogenetic considerations into ex situ prioritization in a manner balanced with other criteria, such as vulnerability. To meet this need, we present the ‘PIECES’ index (Phylogenetically Informed Ex situ Conservation of Endangered Species). PIECES integrates phylogenetic considerations into a flexible framework for prioritizing species across competing objectives using multi-criteria decision analysis. Applying PIECES to prioritizing ex situ conservation of North American angiosperms, we show strong return on investment across multiple objectives, some of which are negatively correlated with each other. A spreadsheet-based decision support tool for North American angiosperms is provided; this tool can be customized to align with different conservation objectives. [ABSTRACT FROM AUTHOR]

1. Phylogenies are increasingly incorporated into ecological studies on the basis that evolutionary relatedness broadly correlates with trait similarity. However, phylogenetic approaches have rarely been applied to monitoring long-term community change or guiding management. 2. We analysed a 25-year resampling data set (1976-2001) of 41 tallgrass prairie remnants (Illinois, USA) to test for phylogenetic signals of plant community structure, change, environmental associations, fire management and functional traits. A community phylogeny was constructed using GenBank sequences, and trait data were acquired from the TRY consortium. Phylogenetic measures of alpha and beta diversity were compared with taxonomic and functional measures. 3. From 1976 to 2001, communities became more phylogenetically clustered relative to null model expectations, that is increasingly restricted to subsets of species more closely related than expected by chance. Phylogeny was a sensitive indicator of environmental gradients and fire management. There were strong relationships between phylogeny and traits: key traits were phylogenetically non-random and phylogenetic diversity was a necessary complement to species richness for explaining variation in trait diversity. 4. Phylogeny revealed a shift in community structure over time, with sites having been phylogenetically random in 1976 but becoming differentiated from each other by 2001. In contrast, measures of taxonomic and functional diversity showed differentiation at both time points. Phylogenetic patterns likely reflected changes in species' abundances mediated by the influence of environmental conditions and fire frequency. 5. Synthesis and applications. Phylogenetic analyses can elucidate factors central to sound monitoring and management of plant communities. In this system, phylogeny was not a proxy for other indicators, but provided information complementing taxonomic-based and trait-based approaches for understanding vegetation structure, change and response to fire management. Phylogenetic approaches to ecological analysis are increasingly accessible, but fuller understanding of phylogeny-trait relationships and further development of user-friendly analytical tools are needed for phylogenetics to widely inform restoration and management. In some systems, targeting phylogenetic diversity may be an effective means for restoring functionally diverse plant communities. [ABSTRACT FROM AUTHOR]

Shifts in plant-community composition following habitat degradation and species invasions can alter ecosystem structure and performance of ecosystem services. In temperate North American woodlands, invasion by aggressive Eurasian shrubs has produced dense thickets with depauperate understory vegetation and increased rates of litter decomposition and nutrient cycling, attributes that could impair storage of carbon as soil organic matter ( SOM). It is important to know if such impairment has occurred and, if so, the extent to which restoration can return this service. We used an oak-woodland restoration chronosequence in northeastern Illinois to contrast structural and functional attributes of unrestored areas dominated by Rhamnus cathartica (common buckthorn) with areas that had undergone buckthorn removal and ongoing, active management for less than 1 to 14 years. With increasing age, restored areas had higher understory plant diversity and cover ( p < 0.0001 and 0.005, respectively) and higher litter mass ( p = 0.018). These structural differences were associated with some evidence of reduced soil erosion ( p = 0.027-0.135) but greater soil CO2 efflux ( p = 0.020-0.033). Total particulate organic matter ( POM) in the soil increased with restoration age, which was driven by increases in the slow-turnover, mineral-associated SOM fraction. However, variance was high and relationships were only weakly significant ( p = 0.082 and 0.083 for total POM and mineral-associated SOM, respectively). Our results suggest that, in addition to better documented biodiversity benefits, beneficial changes to ecosystem properties and processes may also occur with active, long-term restoration of degraded woodlands. [ABSTRACT FROM AUTHOR]

Abstract: A 15N-addition mesocosm experiment was used to study competition for nitrogen (N) between the aggressive cattail species Typha × glauca (T. latifolia × T. angustifolia) Godr. (hybrid cattail) and a suite of native plant species often found in marshes Typha invades. Plant uptake of 15N released from labeled Typha and native-species litter was then measured in a pot experiment with new cohorts of two native plant species (Juncus balticus Willd. and Schoenoplectus acutus Muhlenberg ex Bigelow) grown with and without Typha. In both experiments, species differed in their above- and belowground uptake of 15N, with Typha outperforming the other species (1.7–5.0-times greater mean uptake, P =<0.0001–0.007). Typha then held on more strongly to the N it acquired: newly grown native plants in the pot experiment acquired more 15N from native litter than from Typha litter (1.4–12.0-times greater mean uptake, P =0.0006–0.017). In contrast, Typha showed no differences in N uptake by litter type (P =0.16–0.54). There were no main effects of live Typha on native-plant N uptake (P =0.64–0.86), but there were modest interactions between Typha presence and litter type (P =0.030–0.091). Where native plants and Typha co-occurred, native species matched Typha in recovering 15N from native litter (P =0.17–0.33) but recovered 90–96% less 15N from Typha litter (P =0.020–0.021). Typha''s higher overall N recovery was due to both greater biomass production and uptake efficiency (15N per unit dry weight). Typha''s greater N uptake and retention, repeated over multiple cycles of senescence and new growth, should lead to an increasing appropriation of N away from native species and into living and dead Typha biomass. [Copyright &y& Elsevier]

Purpose: To examine efficacy and safety of dual sirolimus and mycophenolate mofetil systemic immunosuppression as allograft rejection prophylaxis after penetrating keratoplasty in patients at high rejection risk. Design: Prospective, interventional case series. Methods: settings: Single-center subspecialty clinic. patients: Six penetrating transplant recipients at high rejection risk and with no confounding additional cause for high risk of graft failure. All transplant recipient eyes had good visual potential. intervention: Treatment with oral mycophenolate mofetil in combination with sirolimus for 1 year, and sirolimus alone for 2 further years after keratoplasty at doses used in prophylaxis after cadaveric kidney transplantation. main outcomes measures: Interval to first rejection episode, transplant survival, and significant drug adverse effects. Minimum follow-up interval was 13 months after transplantation. Results: Rejection episodes occurred in 3 patients, one of which led to transplant failure. Of the 6 transplants, 5 remained clear at latest follow-up. Hepatotoxicity required discontinuation of mycophenolate in 1 patient, and both drugs were otherwise free of significant adverse effects. Conclusions: Sirolimus and mycophenolate mofetil in combination are effective in extending corneal transplant survival in most but not all high rejection risk patients and generally are well tolerated. Results justify further evaluation of this regimen in a larger controlled study. [ABSTRACT FROM AUTHOR]

Abstract: Trophic support functions for fishes are a key goal of salt marsh restoration. Food availability in restored sites may be enhanced by creation of shallow pools, which are important sources of prey items in tidal wetlands. Young restored salt marshes are typically sparsely vegetated and are subject to rapidly changing geomorphology. Scouring and sedimentation create and fill shallow depressions, producing a shifting mosaic of tidal pools. In a large (8-ha) southern California experimental restoration site, we created shallow pools and assessed their development of foods for fishes. Created pools quickly developed abundant invertebrate prey, with densities exceeding those found in older, naturally formed pools (P <0.0001). Opportunistic mobile and disturbance-associated taxa (calanoid copepods, nematodes, Polydora complex, and Trichocorixa reticulata) accounted for higher invertebrate densities in created pools. We repeated experiments in spring, summer, and fall and found seasonal variability in trophic development. We also applied bottom-up (nitrogen addition) and top-down (fish exclusion) treatments to pools. Some measures of algal biomass were increased by nitrogen fertilization (P =0.001–0.06), but there were no upward-cascading effects on invertebrate composition or abundance. Fish abundance in the site varied seasonally, but there were no compelling effects of fish exclusion treatments on algal or invertebrate abundance. Incorporating shallow depressions into salt marsh restoration projects is a potential tool to jumpstart fish-support functions. [Copyright &y& Elsevier]

Germination biology and dormancy-breaking requirements of fully aquatic (submerged and floating) plant species remain relatively understudied. This is a significant impediment to efforts to restore vegetation in freshwater systems, where the abundance of seeds, and possibility of sowing them in large numbers, suggests underutilized potential for active revegetation. We assessed the influence of seed traits (mass and shape) and two treatments to break dormancy (scarification and gibberellic acid) on the germination of seeds of four macrophyte species after cold-stratification. For all species, untreated seeds did not germinate (0% rate), despite relatively high seed viability (42–90% across species). For Potamogeton illinoensis and P. natans , scarification plus gibberellic acid increased germination the most, to 83% and 35%, respectively (corrected for viability). The other two species remained wholly (Brasenia schreberi) or overwhelmingly (Nuphar variegata) ungerminated. For the two species that did germinate, germination probability increased with seed mass (P. natans and P. illinoensis) and elongation (P. natans). While the small size of trait effects relative to seed treatment effects suggests the latter are more important for revegetation work, the trait patterns highlight evolutionary tradeoffs in seed-size investments. The two Potamogeton species we examined show promise for use in revegetation via seeding, whereas B. schreberi and N. variegata dormancy break has not been adequately developed for these species to be used in seeding-based revegetation. • Four macrophyte species' cold-stratified seeds showed high viability. • These seeds exhibited no germination without dormancy break treatment. • Scarification and gibberellic acid treatment induced germination for Potamogeton spp. • Neither treatment attenuated dormancy of B. schreberi or N. variegata. • For Potamogeton spp. , increasing seed mass and elongation increased germination. [ABSTRACT FROM AUTHOR]

Forecasting invasion risk under future climate conditions is critical for the effective management of invasive species, and species distribution models (SDMs) are key tools for doing so. However, SDM‐based forecasts are uncertain, especially when correlative statistical models extrapolate to nonanalog environmental domains, such as future climate conditions. Different assumptions about the functional form of the temperature–suitability relationship can impact predicted habitat suitability under novel conditions. Hence, methods to understand the sources of uncertainty are critical when applying SDMs. Here, we use high‐resolution predictions of lake water temperatures to project changes in habitat suitability under future climate conditions for an invasive macrophyte (Myriophyllym spicatum). Future suitability was predicted using five global circulation models and three statistical models that assumed different species–temperature functional responses. The suitability of lakes for M. spicatum was overall predicted to increase under future climate conditions, but the magnitude and direction of change in suitability varied greatly among lakes. Variability was most pronounced for lakes under nonanalog temperature conditions, indicating that predictions for these lakes remained highly uncertain. Integrating predictions from SDMs that differ in their species–environment response function, while explicitly quantifying uncertainty across analog and nonanalog domains, can provide a more robust and useful approach to forecasting invasive species distribution under climate change. [ABSTRACT FROM AUTHOR]

Aquatic invasive species (AIS) are one of the greatest threats to the functioning of aquatic ecosystems worldwide. Once an invasive species has been introduced to a new region, many governments develop management strategies to reduce further spread. Nevertheless, managing AIS in a new region is challenging because of the vast areas that need protection and limited resources. Spatial heterogeneity in invasion risk is driven by environmental suitability and propagule pressure, which can be used to prioritize locations for surveillance and intervention activities. To better understand invasion risk across aquatic landscapes, we developed a simulation model to estimate the likelihood of a waterbody becoming invaded with an AIS. The model included waterbodies connected via a multilayer network that included boater movements and hydrological connections. In a case study of Minnesota, we used zebra mussels (Dreissena polymorpha) and starry stonewort (Nitellopsis obtusa) as model species. We simulated the impacts of management scenarios developed by stakeholders and created a decision‐support tool available through an online application provided as part of the AIS Explorer dashboard. Our baseline model revealed that 89% of new zebra mussel invasions and 84% of new starry stonewort invasions occurred through boater movements, establishing it as a primary pathway of spread and offering insights beyond risk estimates generated by traditional environmental suitability models alone. Our results highlight the critical role of interventions applied to boater movements to reduce AIS dispersal. [ABSTRACT FROM AUTHOR]

To efficiently detect aquatic invasive species early in an invasion when control may still be possible, predictions about which locations are likeliest to be occupied are needed at fine scales but are rarely available. Occupancy modeling could provide such predictions given data of sufficient quality and quantity. We assembled a data set for the macroalga starry stonewort (Nitellopsis obtusa) across Minnesota and Wisconsin, USA, where it is a new and high-priority invader. We used these data to construct a multi-season, single-species spatial occupancy model that included biotic, abiotic, and movement-related predictors. Distance to the nearest access was an important occurrence predictor, highlighting the likely role boats play in spreading starry stonewort. Fetch and water depth also predicted occupancy. We estimated an average detection probability of 63% at sites with mean non-N. obtusa plant cover, declining to ~ 38% at sites with abundant plant cover, especially that of other Characeae. We recommend that surveyors preferentially search for starry stonewort in areas of shallow depth and high fetch close to boat accesses. We also recommend searching during late summer/early fall when detection is likelier. This study illustrates the utility of fine-scale occupancy modeling for predicting the locations of nascent populations of difficult-to-detect species. [ABSTRACT FROM AUTHOR]

The use of targeted grazing to control undesired plants as a component of ecological restoration is gaining in popularity, but there is considerable uncertainty among land managers about the effectiveness of this approach. We synthesized existing literature on the use of livestock (ruminants, swine, and equids) to control undesired plants using a meta‐analysis to address questions about the effectiveness of the approach. Seventy studies matched our inclusion criteria; these comprised 86% peer‐reviewed journal articles and 14% gray literature. Studies were conducted in 17 countries but highly concentrated in the United States and Europe. Cattle, goats, horses, and sheep were used for vegetation management in the studies. Most target plant species were nonnative perennial forbs. Median study duration was 3 years, with a maximum of 10 years. We found that, overall, the use of targeted grazing significantly reduced undesired plants and significantly increased plant species richness. However, several important questions remain. In particular, further research is needed to differentiate temporary defoliation from actual plant mortality, to separate the contributions of native versus nonnative species to gains in plant species richness, and to address longer term outcomes following grazing cessation. [ABSTRACT FROM AUTHOR]

Phylogenetic and functional diversity are theorised to increase invasion resistance. Experimentally testing whether plant communities higher in these components of diversity are less invasible is an important step for guiding restoration designs.To investigate how phylogenetic and functional diversity of vegetation affect invasion resistance in a restoration setting, we used experimental prairie restoration plots. The experiment crossed three levels of phylogenetic diversity with two levels of functional diversity while species richness was held constant. We allowed invaders to colonise plots; these included native species from neighbouring plots and non‐native invasive species from a surrounding old field. We tested if invader biomass was influenced by phylogenetic and functional diversity, and phylogenetic and hierarchical trait distances between invaders and planted species. We binned each invader into three categories: native species from neighbouring experimental plots (site‐specific invaders), native species not part of the experimental species pool (native invaders) or non‐native species (non‐native invaders).Counter to expectation, both non‐native and native invaders became more abundant in more phylogenetically diverse plots. However, plots with higher abundance of planted Asteraceae, a dominant family of the tallgrass prairie, had lower invader biomass for both native and non‐native invaders.We also found that hierarchical trait differences shaped invasion. The species that became most abundant were non‐native invaders that were taller, and native invaders with low specific leaf area relative to planted species. Site‐specific invaders were not influenced by any plot‐level diversity metrics tested.Synthesis and application: Our results suggest that greater phylogenetic diversity may lower resistance to invasion. This effect may be due to more even but sparser niche packing in high‐diversity plots, associated with greater availability of unsaturated niche space for colonisation. However, trait composition fostered invasion resistance in two ways in our study. First, establishment of native species with strongly dominant traits may confer invasion resistance. Second, species mixes that optimise trait differences between planted vegetation and likely invaders may enhance invasion‐resistance. [ABSTRACT FROM AUTHOR]

The article presents insights on the role of phylogenetic diversity in ecological restoration. It notes that phylogeny integrates the evolutionary history of functional traits and provides a useful predictor of ecological dynamics that often outperform trait-based predictors. It cites the three main questions that need to be addressed by a research on integrating phylogeny into ecological restoration research.

Often facilitated by human-mediated pathways, aquatic invasive species are a threat to the health and biodiversity of global ecosystems. We present a novel approach incorporating survey data of watercraft movement in a social network analysis to reconstruct potential pathways of aquatic invasive species spread between lakes. As an example, we use the green alga Nitellopsis obtusa, also known as starry stonewort, an aquatic invasive species affecting the Great Lakes region in the United States and Canada. The movement of algal fragments via human-mediated pathways (i.e., watercraft) has been hypothesized as the primary driver of starry stonewort invasion. We used survey data collected at boat ramps during the 2013 and 2014 open-water seasons to describe the flow of watercraft from Lake Koronis, where N. obtusa was first detected in Minnesota, to other lakes in the state. Our results suggest that the risk of N. obtusa expansion is not highly constrained by geographic proximity and management efforts should consider highly connected lakes. Estimating human movement via network analysis may help to explain past and future routes of aquatic invasive species infestation between lakes and can improve evidence-based prevention and control efforts. [ABSTRACT FROM AUTHOR]

Abstract: Understanding the processes that influence the diversity of ecological communities and their susceptibility to invasion by exotic species remains a challenge in ecology. In many systems, a positive relationship between the richness of native species and exotic species has been observed at larger spatial (e.g., regional) scales, while a negative pattern has been observed at local (e.g., plot) scales. These patterns are widely attributed to (1) biotic interactions, particularly biotic resistance, limiting invasions in high‐diversity locations, producing negative local‐scale relationships, and (2) native and exotic richness covarying at larger spatial scales as a function of environmental conditions and heterogeneity, producing positive large‐scale relationships. However, alternative processes can produce similar patterns and need to be critically evaluated to make sound inferences about underlying mechanisms. We aggregated a large dataset of aquatic vegetation surveys from 1,102 Minnesota shallow lakes collected over 13 years to quantify spatial and temporal patterns of community composition. Using those data and additional information on environmental conditions we evaluated evidence for four distinct mechanisms that could drive patterns of native and exotic species richness: biotic resistance, competitive exclusion, environmental filtering and environmental heterogeneity. We found the classic pattern of a negative native‐exotic richness relationship at local scales and a positive relationship at lake scales. However, we found no evidence for local‐scale biotic resistance; instead, competitive exclusion by invasive species appeared to reduce native species richness after locations became invaded. Evaluating the influence of environmental filtering and heterogeneity, we found that native and exotic species occupied somewhat different niches. Invaders were less sensitive to environmental gradients and more tolerant of a wider range of conditions. This segregation of habitat preferences alone could produce a negative local native‐exotic richness relationship and a positive regional pattern without the involvement of biotic interactions. Synthesis. Our findings conflict with established expectations, which come from research predominantly conducted in terrestrial ecosystems. This illustrates the importance of explicitly evaluating underlying mechanisms in diversity‐invasibility research and for comparisons across different types of ecosystems. Identification of different drivers of diversity also has direct implications for decisions about management of freshwater plant communities. [ABSTRACT FROM AUTHOR]

Phylogenetic and functional diversity are relevant for restoration planning, as they influence important ecosystem functions and services. However, it is unknown whether initial phylogenetic and functional diversity of restorations as planned and planted are maintained over time, that is, the extent to which diversity of the restoration planting is reflected in the diversity of the resulting plant community. Furthermore, in the tallgrass prairie, many restorations are planted from seed. Among‐species variation in emergence and establishment affects the transition from seed mixes to realized plant communities in these restorations. We evaluated emergence and early establishment of experimental communities in a biodiversity plot experiment designed to test how phylogenetic and functional diversity influence restoration outcomes. We planted the same experimental communities starting from both seeds and plugs to assess differences in establishment. Our results suggest that phylogenetically and functionally diverse species mixes tend to produce phylogenetically and functionally diverse restored plant communities. After 3 years, experimental communities generally maintained their phylogenetic and functional diversity from seed and plug mixes to established vegetation, despite declines in species richness. While plots planted from seeds had on average 1.3 fewer species than plots planted from plugs, phylogenetic and functional diversity did not significantly differ between the two. Furthermore, most species exhibited no significant differences in percent cover when planted from seeds or plugs. Seeds are generally more cost‐effective for restoration than plugs, and our results indicate these two establishment methods achieved similar biodiversity outcomes. [ABSTRACT FROM AUTHOR]

Aim A surprising finding of genetic studies of Phragmites australis is that native populations, whether in Europe or North America, are characterized by lower genetic diversity than non-native populations. What is not clear is whether higher diversity within invasive stands results from disturbance facilitating sexual reproduction or whether individuals with higher diversity have greater invasion potential. Location Upper Midwest, United States, North America. Methods To answer this question, we investigated genetic structure of native and non-native P. australis stands at multiple spatial scales and under differing levels of anthropogenic disturbance. Our goals were to assess the influence of habitat disturbance on genetic structure and determine whether patterns differed in native versus non-native stands. We also screened for hybrid genotypes, which have not been reported from this region. Results When controlling for disturbance, native and non-native P. australis exhibited relatively similar within-site genetic diversity and degrees of clonal growth, suggesting that their spread is comparably reliant on clonal versus sexual dispersal. In all cases, discrete clumps of P. australis were composed of multiple, closely related genotypes, indicating seed heads as the key dispersal units. The genetic structure of P. australis stands did not differ with disturbance; however, only non-native P. australis was found in highly disturbed anthropogenic habitats. Native P. australis stands exhibited lower genetic diversity overall, lower sexual reproduction in less disturbed sites and greater isolation by distance and differentiation among sites, which is consistent with its longer residence time in this region. We found no evidence of hybrid genotypes, despite native and non-native stands sometimes co-occurring. Main conclusions Our results suggest that invasion by non-native P. australis is sporadic, associated with disturbance and involves closely related individuals, likely derived from a single seed head. The ability of the non-native lineage to exploit a variety of anthropogenic habitats helps to explain its invasiveness. [ABSTRACT FROM AUTHOR]

Nitellopsis obtusa ([Desvaux] J. Groves [1919]; Characeae), known as starry stonewort, is an invasive macroalga in Laurentian Great Lakes states and provinces in North America. Because of its potential negative impacts on native ecosystems and recreation, N. obtusa has become a high-priority target for management. However, there is a critical lack of foundational information on the efficacy of different algaecides, and concentrations thereof, for N. obtusa control. Additionally, control of N. obtusa bulbils--asexual reproductive structures that are the main pathway for the establishment of new plants--has proven difficult. We tested the efficacy of six commonly used copper-based algaecides, at a series of copper concentrations up to the maximum labeled rate, on N. obtusa thalli (photosynthetic aboveground tissues) and bulbils in controlled laboratory experiments. Bulbils were placed above and below sediment in separate experiments to evaluate whether sediment acted as a barrier to treatment. At 14 days after treatment (DAT), there were significant reductions in thalli biomass (34% and 40%) for two algaecides at the highest concentration evaluated (1.0 mg Cu L-1) and significant thalli discoloration at 0.75 and 1.0 mg Cu L-1 for four algaecides. There were no significant negative effects on N. obtusa thalli biomass or discoloration at lower concentrations of any product. For belowsediment bulbils, none of the algaecides reduced N. obtusa viability compared to untreated controls by 56 DAT, and viability was significantly greater than in controls for three different algaecides at 0.25 mg Cu L-1. For above-sediment bulbils, there was low sprouting across all algaecide treatments and untreated controls, indicating inhospitable growing conditions. These findings provide a baseline for improvement of chemical treatment options for N. obtusa, provide guidance for future research on N. obtusa control, and underscore the challenges in achieving sustained N. obtusa control. [ABSTRACT FROM AUTHOR]

The prediction that higher biodiversity leads to denser niche packing and thus higher community resistance to invasion has long been studied, with species richness as the predominant measure of diversity. However, few studies have explored how phylogenetic and functional diversity, which should represent niche space more faithfully than taxonomic diversity, influence community invasibility, especially across longer time frames and over larger spatial extents.We used a 15‐year, 150‐site grassland dataset to assess relationships between invasive plant abundance and phylogenetic, functional and taxonomic diversity of recipient native plant communities. We analysed the dataset both pooled across all surveys and longitudinally, leveraging time‐series data to compare observed patterns in invasion with those predicted by two community assembly processes: biotic resistance and competitive exclusion. We expected more phylogenetically and functionally diverse communities to exhibit greater resistance to invasion.With the pooled dataset, we found support for the long‐standing observation that communities with more native species have lower abundance of invasive species, and a more novel finding that more phylogenetically diverse communities had higher abundance of invasive species. We found no influence of aggregate (multivariate) functional diversity on invasion, but assemblages with taller plants, lower variability in plant height and lower seed mass were less invaded. Viewed longitudinally, the phylogenetic diversity relationship was reversed: the most phylogenetically diverse communities were most resistant to invasion. This apparent discrepancy suggests invasion dynamics are influenced by both site attributes and biotic resistance and emphasizes the value in studying invasion across time.Synthesis. Our results provide insight into the nuances of the diversity–invasibility relationship: invasion dynamics differed for different dimensions of diversity and depending on whether the relationship was evaluated longitudinally. Our findings highlight the limitations of using single time‐point 'snapshots' of community composition to infer invasion mechanisms. [ABSTRACT FROM AUTHOR]

Phylogenetic ecology uses evolutionary history to improve understanding of plant interactions. Phylogenetic distance can mediate plant interactions such as competition (e.g., via limiting similarity) and facilitation (e.g., via niche complementarity), influencing community assembly patterns. Previous research has found evidence both for and against a relationship between phylogenetic distance and the strength of plant interactions, and has found that other factors, such as trait differences, may be more influential. In addition to phylogenetic distance and species' traits, environmental conditions can also influence competition, with facilitative interactions—particularly among distantly related species—potentially becoming more pronounced under stressful, resource-limited conditions. We tested the prediction that greater phylogenetic distance is associated with decreased competition in a greenhouse experiment using plant species of the North American tallgrass prairie. We calculated the Relative Interaction Index for 81 species pairs using plant height, leaf length, and biomass as indicators of performance. We found that phylogenetic distance alone did not significantly affect competition. However, the interaction between phylogenetic distance and stressful conditions (sandier soils with low nutrient availability and water retention vs. resource-rich potting soil) altered plant traits and competition. Under stressful conditions, more distantly related species competed more strongly, leading to smaller plants. Conversely, under benign conditions more distantly related species pairs competed less and were larger. These results were contrary to our expectations that distant relatives would compete less under stressful conditions. Our experiment provides evidence that, while relatedness alone may not drive competition, phylogenetic distance can nonetheless be influential through interactions with environmental conditions. [ABSTRACT FROM AUTHOR]

Aim: Availability of uniformly collected presence, absence, and abundance data remains a key challenge in species distribution modeling (SDM). For invasive species, abundance and impacts are highly variable across landscapes, and quality occurrence and abundance data are critical for predicting locations at high risk for invasion and impacts, respectively. We leverage a large aquatic vegetation dataset comprising point‐level survey data that includes information on the invasive plant Myriophyllum spicatum (Eurasian watermilfoil) to: (a) develop SDMs to predict invasion and impact from environmental variables based on presence–absence, presence‐only, and abundance data, and (b) compare evaluation metrics based on functional and discrimination accuracy for presence–absence and presence‐only SDMs. Location: Minnesota, USA. Methods: Eurasian watermilfoil presence–absence and abundance information were gathered from 468 surveyed lakes, and 801 unsurveyed lakes were leveraged as pseudoabsences for presence‐only models. A Random Forest algorithm was used to model the distribution and abundance of Eurasian watermilfoil as a function of lake‐specific predictors, both with and without a spatial autocovariate. Occurrence‐based SDMs were evaluated using conventional discrimination accuracy metrics and functional accuracy metrics assessing correlation between predicted suitability and observed abundance. Results: Water temperature degree days and maximum lake depth were two leading predictors influencing both invasion risk and abundance, but they were relatively less important for predicting abundance than other water quality measures. Road density was a strong predictor of Eurasian watermilfoil invasion risk but not abundance. Model evaluations highlighted significant differences: Presence–absence models had high functional accuracy despite low discrimination accuracy, whereas presence‐only models showed the opposite pattern. Main conclusion: Complementing presence–absence data with abundance information offers a richer understanding of invasive Eurasian watermilfoil's ecological niche and enables evaluation of the model's functional accuracy. Conventional discrimination accuracy measures were misleading when models were developed using pseudoabsences. We thus caution against the overuse of presence‐only models and suggest directing more effort toward systematic monitoring programs that yield high‐quality data. [ABSTRACT FROM AUTHOR]

Charles Darwin posited two alternative hypotheses to explain the success of nonnative species based on their relatedness to natives: nonnative species that are closely related to native species could experience (1) higher invasion success because of an increased probability of habitat suitability (conferred by trait similarity) or (2) lower invasion success due to biotic interference, such as competition and limiting similarity. The paradox raised by the opposing predictions of these two hypotheses has been termed "Darwin's naturalization conundrum" (DNC). Using plant communities measured repeatedly across an experimental fire gradient in an oak savanna (Minnesota, USA) over 31 yr, we evaluated the DNC by incorporating taxonomic, functional, and phylogenetic information. We used a "focal‐species" approach, in which the taxonomic, functional, and phylogenetic structure of species co‐occurring with a given nonnative (focal) species in local communities was quantified. We found three main results: first, nonnative species tended to co‐occur most with closely related natives, except at the extreme ends of the fire gradient (i.e., in communities with no fire and those subjected to high fire frequencies); second, with increasing fire frequency, nonnative species were functionally more similar to native species in recipient communities; third, functional similarity between co‐occurring nonnatives and natives was stable over time, but their phylogenetic similarity was not, suggesting that dynamic external forces (e.g., climate variability) influenced the phylogenetic relatedness of nonnatives to natives. Our results provide insights for understanding invasion dynamics across environmental gradients and highlight the importance of evaluating different dimensions of biodiversity in order to draw stronger inferences regarding species co‐occurrence at different spatial and temporal scales. [ABSTRACT FROM AUTHOR]

Potamogeton crispus (curlyleaf pondweed) and Myriophyllum spicatum (Eurasian watermilfoil) are widely thought to competitively displace native macrophytes in North America. However, their perceived competitive superiority has not been comprehensively evaluated. Coexistence theory suggests that invader displacement of native species through competitive exclusion is most likely where high niche overlap results in competition for limiting resources. Thus, evaluation of niche similarity can serve as a starting point for predicting the likelihood of invaders having direct competitive impacts on resident species. Across two environmental gradients structuring macrophyte communities—water depth and light availability—both P. crispus and M. spicatum are thought to occupy broad niches. For a third dimension, phenology, the annual growth cycle of M. spicatum is typical of other species, whereas the winter-ephemeral phenology of P. crispus may impart greater niche differentiation and thus lower risk of native species being competitively excluded. Using an unprecedented dataset comprising 3404 plant surveys from Minnesota collected using a common protocol, we modeled niches of 34 species using a probabilistic niche framework. Across each niche dimension, P. crispus had lower overlap with native species than did M. spicatum; this was driven in particular by its distinct phenology. These results suggest that patterns of dominance seen in P. crispus and M. spicatum have likely arisen through different mechanisms, and that direct competition with native species is less likely for P. crispus than M. spicatum. This research highlights the utility of fine-scale, abundance-based niche models for predicting invader impacts. [ABSTRACT FROM AUTHOR]

Background: The KERALINK trial tests the hypothesis that corneal cross-linking (CXL) treatment reduces the progression of keratoconus in comparison to standard care in patients aged 10-16 years. This article describes the statistical analysis plan for this trial as an update to the published protocol. It is written before the end of the patient follow-up, while the outcome of the trial is still unknown.Design and Methods: KERALINK is a randomised controlled, observer-masked, multicentre trial in progressive keratoconus comparing epithelium-off CXL with standard care, including spectacles or contact lenses as necessary for best-corrected acuity. Keratoconus is a disorder of the shape of the cornea in which the normally round dome-shaped clear front window of the eye (cornea) thins progressively leading to a cone-like bulge. This impairs the ability of the eye to focus properly, causing reduced vision which requires spectacle or contact lens wear or, in a minority of patients, eventually corneal replacement by a transplant for best vision. The primary outcome measure is the between-group difference in K2 at 18 months adjusted for K2 at baseline examination. K2 is the value of the steepest corneal meridian as measured on Pentacam topography. Secondary outcomes are keratoconus progression, time to keratoconus progression, visual acuity, refraction, apical corneal thickness and adverse events. Patient-reported effects will be explored by questionnaires. We describe in detail the statistical aspects of KERALINK: the outcome measures, the sample size calculation, general analysis principles, the planned descriptive statistics and statistical models, and planned subgroup and sensitivity analyses.Discussion: The KERALINK statistical analysis will provide comprehensive and precise information on the relative effectiveness of the two treatments. The plan will be implemented in May 2020 when follow-up for the trial is completed.Trial Registration: EudraCT, 2016-001460-11. Registered on 19 May 2016. [ABSTRACT FROM AUTHOR]

Plant invasions result in biodiversity losses and altered ecological functions, though quantifying loss of multiple ecosystem functions presents a research challenge. Plant phylogenetic diversity correlates with a range of ecosystem functions and can be used as a proxy for ecosystem multifunctionality. Laurentian Great Lakes coastal wetlands are ideal systems for testing invasive species management effects because they support diverse biological communities, provide numerous ecosystem services, and are increasingly dominated by invasive macrophytes. Invasive cattails are among the most widespread and abundant of these taxa. We conducted a three‐year study in two Great Lakes wetlands, testing the effects of a gradient of cattail removal intensities (mowing, harvest, complete biomass removal) within two vegetation zones (emergent marsh and wet meadow) on plant taxonomic and phylogenetic diversity. To evaluate native plant recovery potential, we paired this with a seed bank emergence study that quantified diversity metrics in each zone under experimentally manipulated hydroperiods. Pretreatment, we found that wetland zones had distinct plant community composition. Wet meadow seed banks had greater taxonomic and phylogenetic diversity than emergent marsh seed banks, and high‐water treatments tended to inhibit diversity by reducing germination. Aboveground harvesting of cattails and their litter increased phylogenetic diversity and species richness in both zones, more than doubling richness compared to unmanipulated controls. In the wet meadow, harvesting shifted the community toward an early successional state, favoring seed bank germination from early seral species, whereas emergent marsh complete removal treatments shifted the community toward an aquatic condition, favoring floating‐leaved plants. Removing cattails and their litter increased taxonomic and phylogenetic diversity across water levels, a key environmental gradient, thereby potentially increasing the multifunctionality of these ecosystems. Killing invasive wetland macrophytes but leaving their biomass in situ does not address their underlying mechanism of dominance and is less effective than more intensive treatments that also remove their litter. [ABSTRACT FROM AUTHOR]

Highlights • We developed an ecological niche model for the invasive alga Nitellopsis obtusa. • We make fine scale predictions based on lake conditions rather than climate data. • We predict risks for individual lakes across Minnesota and Wisconsin. • Random forest and boosted regression trees approaches perform better than MADIFA. Abstract Starry stonewort (Nitellopsis obtusa ; Characeae) is a freshwater macroalga that is considered an invasive species in North America and has only recently been identified in the upper Midwest states of Minnesota and Wisconsin (USA). While the current known extent of N. obtusa invasion in the Midwestern U.S. is limited, there is significant potential habitat for continued expansion and thus a pressing need to target surveillance and response efforts to limit further spread. Here we use data on N. obtusa presence and lake-level environmental conditions from locations in New York state to train a set of ecological niche models using three separate algorithms: random forests, boosted regression trees, and ecological niche factor analysis. These models were then used to predict habitat suitability and potential invasion risk for a set of ∼900 lakes in the upper Midwest using publicly available lake-level water quality data. Based on a cross-validation study we found that the random forest method provided the most accurate predictions, though only marginally better than boosted regression trees. Ecological niche factor analysis, while offering better than random predictions, had the highest cross-validation error rates. Though there were some inconsistencies between modeling approaches, all three tended to agree on regions of relatively high risk in central Minnesota and eastern Wisconsin and relatively low risk in north-central Wisconsin. However, there are inherent limitations to developing ecological niche models with data from one geographical region and predicting into a different region, thus there is a need for additional efforts to validate model predictions. [ABSTRACT FROM AUTHOR]

Abstract: Traits are important for understanding how plant communities assemble and function, providing a common currency for studying ecological processes across species, locations, and habitat types. However, the majority of studies relating species traits to community assembly rely upon vegetative traits of mature plants. Seed traits, which are understudied relative to whole‐plant traits, are key to understanding assembly of plant communities. This is particularly true for restored communities, which are typically started de novo from seed, making seed germination a critical first step in community assembly and an early filter for plant establishment. We experimentally tested the effects of seed traits (mass, shape, and embryo to seed size ratio) and phylogeny on germination response in 32 species commonly used in prairie grassland restoration in the Midwestern USA, analyzing data using time‐to‐event (survival) analysis. As germination is also influenced by seed dormancy, and dormancy break treatments are commonly employed in restoration, we also tested the effects of two pretreatments (cold stratification and gibberellic acid application) on time to germination. Seed traits, phylogeny, and seed pretreatments all affected time to germination. Of all traits tested, variables related to seed shape (height and shape variance) best predicted germination response, with high‐variance (i.e., pointier and narrower) seeds germinating faster. Phylogenetic position (the location of species on the phylogenetic tree relative to other tested species) was also an important predictor of germination response, that is, closely related species showed similar patterns in time to germination. This was true despite the fact that all measured seed traits showed phylogenetic signal, therefore phylogeny provided residual information that was not already captured by measured seed traits. Seed traits, phylogenetic position, and germination pretreatments were important predictors of germination response for a suite of species commonly used in grassland restoration. Shape traits were especially important, while mass, often the only seed trait used in studies of community assembly, was not a strong predictor of germination timing. These findings illustrate the ecological importance of seed traits that are rarely incorporated into functional studies of plant communities. This information can also be used to advance restoration practice by guiding restoration planning and seed mix design. [ABSTRACT FROM AUTHOR]

Ecological restoration is critical for mitigating habitat loss and providing ecosystem services. However, restorations often have lower diversity than remnant, reference sites. Phylogenetic diversity is an important component of biodiversity and ecosystem function that has only recently been used to evaluate restoration outcomes. To move towards prediction in the restoration of biodiversity, it is necessary to understand how phylogenetic diversity of restorations compares with that of reference sites, and where deficits are found, to evaluate factors constraining phylogenetic diversity., We quantified plant taxonomic and phylogenetic diversity in eastern tallgrass prairie, one of the most endangered ecosystems on earth. We measured diversity at large (site) and small (plot) scales in 19 restored prairies and compared patterns with those from 41 remnant prairies. To evaluate how environmental conditions and management actions influence outcomes, we tested the effects of soil properties and seed mix composition on diversity of restorations., Restored prairies were less phylogenetically diverse than remnants at both spatial scales. On the other hand, the total species richness of remnant and restored prairies did not significantly differ, but remnants had higher native richness. Restored communities were taxonomically and phylogenetically distinct from remnants., Soil properties (moisture and pH) influenced phylogenetic diversity and composition. There were positive relationships between the taxonomic and phylogenetic diversity of seed mixes and resulting diversity of planted assemblages (excluding volunteer species). Species in seed mixes were more closely related than expected by chance, and several clades found in remnant prairies were missing from seed mixes., Synthesis and applications. Restored tallgrass prairies had lower phylogenetic diversity than remnant prairies, which may contribute to the widely observed phenomenon of restorations not being functionally equivalent to reference sites. It is encouraging for restoration efforts that seed mix phylogenetic diversity predicted phylogenetic diversity of planted assemblages. This indicates that designing phylogenetically diverse seed mixes for restoration is beneficial. In addition, clades found in reference sites that are missing from restoration seed mixes could be added to new or existing restorations to reduce gaps in phylogenetic diversity. Further work on the effects of management on phylogenetic diversity is needed to advance restoration of biodiversity. [ABSTRACT FROM AUTHOR]

Starry stonewort (Nitellopsis obtusa) is an alga that has emerged as an aquatic invasive species of concern in the United States. Where established, starry stonewort can interfere with recreational uses of water bodies and potentially have ecological impacts. Incipient invasion of starry stonewort in Minnesota provides an opportunity to predict future expansion in order to target early detection and strategic management. We used ecological niche models to identify suitable areas for starry stonewort in Minnesota based on global occurrence records and present-day and future climate conditions. We assessed sensitivity of forecasts to different parameters, using four emission scenarios (i.e., RCP 2.6, RCP 4.5, RCP 6, and RCP 8.5) from five future climate models (i.e., CCSM, GISS, IPSL, MIROC, and MRI). From our niche model analyses, we found that (i) occurrences from the entire range, instead of occurrences restricted to the invaded range, provide more informed models; (ii) default settings in Maxent did not provide the best model; (iii) the model calibration area and its background samples impact model performance; (iv) model projections to future climate conditions should be restricted to analogous environments; and (v) forecasts in future climate conditions should include different future climate models and model calibration areas to better capture uncertainty in forecasts. Under present climate, the most suitable areas for starry stonewort are predicted to be found in central and southeastern Minnesota. In the future, suitable areas for starry stonewort are predicted to shift in geographic range under some future climate models and to shrink under others, with most permutations indicating a net decrease of the species’ suitable range. Our suitability maps can serve to design short-term plans for surveillance and education, while future climate models suggest a plausible reduction of starry stonewort spread in the long-term if the trends in climate warming remain. [ABSTRACT FROM AUTHOR]

The denitrification enzyme activity assay (DEA) and other ex situ , incubation-based methods are widely used for measuring biogeochemical transformations. DEA does not provide direct measurements of denitrification rates in situ , but rather denitrification potential under laboratory conditions over the course of an incubation with resource limitations removed. Despite recognized limitations, DEA has several advantages. In particular, it is a relatively simple and low-cost method considered reliable for comparing relative differences in denitrification, for example between areas subjected to different management treatments. However, a critical but, to our knowledge, untested assumption of DEA is that bacterial composition remains static during the assay, i.e., the microbial community being assayed is equivalent to the original community collected from the field. If this assumption is violated, it could result in flawed estimates of relative differences between samples. We tested the static-community assumption using high-throughput sequencing to measure differences in bacterial community composition between samples from two different wetland vegetation types over the course of standard DEA incubations. We also compared samples that were or were not treated with a standard amendment solution to differentiate amendment effects from “bottle effects” of time spent under storage and laboratory conditions. We found that initially distinct bacterial communities became less similar to each other during short-term cold storage, but then became more similar during incubation, with a net result of samples converging in composition. Surprisingly, there were no effects of amendment solution; bottle effects alone accounted for these changes. This raises concern that potentially important differences in wetland denitrification, or other processes measured using ex situ methods, could be obscured by changes in bacterial community composition that arise as an artifact of laboratory incubations. [ABSTRACT FROM AUTHOR]

Isoëtes butleri Engelm. (Butler’s Quillwort) is a lycopod endemic to the central and southeastern United States. It inhabits sparsely vegetated moist depressions within dolomite prairies that become ephemeral wetlands in the spring. Classified as endangered in portions of its range (Illinois and Kentucky), little is known about the ecology and genetics of I. butleri . In Illinois, the five known populations are disjunct from all other known populations, and there is concern that these populations could be vulnerable to a number of threats, including a lack of suitable microhabitats, displacement by other plant species, accumulation of plant litter, and low genetic diversity and limited gene flow. We evaluated these putative threats by analyzing demographic data collected by Plants of Concern, a citizen-science rare-plant monitoring program; performing experimental litter removals; and assessing population genetic structure. There were no significant differences in soil nutrient availability in topographically similar depressions with and without I. butleri ; however, areas inhabited by I. butleri had lower abundance of woody species and higher abundance of conservative (habitat specialist) species than uninhabited areas. Following experimental litter removal, I. butleri exhibited lower size but higher density and recruitment. We found that all populations had high genetic diversity. However, there was also evidence of high inbreeding, which may be due to spatially fine-scale genetic structure and poor dispersal ability. Our findings suggest that reductions of woody plant growth and accumulated litter—both of which can be achieved through prescribed fire—should be management priorities for I. butleri conservation. [ABSTRACT FROM AUTHOR]

Historical information spanning different temporal scales (from tens to millions of years) can influence restoration practice by providing ecological context for better understanding of contemporary ecosystems. Ecological history provides clues about the assembly, structure, and dynamic nature of ecosystems, and this information can improve forecasting of how restored systems will respond to changes in climate, disturbance regimes, and other factors. History recorded by humans can be used to generate baselines for assessing changes in ecosystems, communities, and populations over time. Paleoecology pushes these baselines back hundreds, thousands, or even millions of years, offering insights into how past species assemblages have responded to changing disturbance regimes and climate. Furthermore, archeology can be used to reconstruct interactions between humans and their environment for which no documentary records exist. Going back further, phylogenies reveal patterns that emerged from coupled evolutionary-ecological processes over very long timescales. Increasingly, this information can be used to predict the stability, resilience, and functioning of assemblages into the future. We review examples in which recorded, archeological, paleoecological, and evolutionary information has been or could be used to inform goal setting, management, and monitoring for restoration. While we argue that long-view historical ecology has much to offer restoration, there are few examples of restoration projects explicitly incorporating such information or of research that has evaluated the utility of such perspectives in applied management contexts. For these ideas to move from theory into practice, tests performed through research-management partnerships are needed to determine to what degree taking the long view can support achievement of restoration objectives. [ABSTRACT FROM AUTHOR]

ABSTRACT Wetland loss, biological invasions, and ecological restoration are major factors altering wetland resources in the Midwestern United States. Large-scale plant-community change associated with these factors is an under-investigated, potentially strong driver of habitat suitability for wetland-dependent wildlife, such as secretive marsh birds (SMBs), which are of widespread conservation concern. We employed multi-year, hierarchical Bayesian occupancy modeling to investigate sensitivity of 3 SMB species (American bittern, sora, and Virginia rail) to habitat and vegetation characteristics in Wisconsin, USA. We contrasted habitat characteristics and SMB occupancy in natural wetlands with those restored under the federally funded Wetlands Reserve Program (WRP). We also examined the extent to which SMB occupancy was explained by 3 levels of habitat assessment that encompassed different spatial scales and levels of sampling effort (landscape, rapid, and intensive). All species were significantly associated with variables derived from intensive assessment, and showed high sensitivity to differences in plant-community composition and vegetation quality. Both American bittern and Virginia rail were negatively associated with abundance of the invasive wetland grass, Phalaris arundinacea (reed canarygrass), and were positively associated with an indicator of plant-community quality (mean coefficient of conservatism, or C-value). Sora occupancy was positively associated with Typha (cattail) abundance. For all 3 species, occupancy was greater in natural sites than in restored sites, which were characterized by greater Phalaris abundance and lower mean C-values. Our results show broad agreement between botanical and avian indicators of wetland quality, suggesting that enhancing the condition of wetland vegetation can yield ancillary benefits for SMBs. In this region, efforts to control Phalaris and restore diverse, native-dominated plant communities are likely to increase wetlands' capacity to support SMBs. © 2015 The Wildlife Society. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the incidence and outcome of cornea transplant rejection following endothelial keratoplasty (EK) and penetrating keratoplasty (PK) for Fuchs endothelial dystrophy (FED) and pseudophakic bullous keratopathy (PBK). Design: Multicenter cohort study. Methods: Patients registered on the United Kingdom Transplant Registry (UKTR) who had an EK or PK for FED or PBK between April 1, 2005 and March 31, 2011 were included. Data were collected from UKTR forms at 1 and 2 years. Postoperative steroid use varies between surgeons and cannot be captured in this reporting system. Rejection events were identified as those recorded as endothelial rejection. Results: A total of 3486 corneal transplants were undertaken: 1973 for FED, 1513 for PBK. For FED, 2-year rejection-free survival was 93% (95% confidence interval [CI] 90%-94%) for PK and 94% (95% CI 92%-96%) for EK (P = .3). In transplants that had a rejection episode, 50% of PKs (17) and 60% of EKs (15) subsequently failed. For PBK, 2-year rejection-free survival for PK was 88% (95% CI 86%-90%) and 90% (95% CI 86%-92%) for EK (P = .6). In transplants that had a rejection episode, 85% of PKs (41) and 76% of EKs (22) subsequently failed. Inflammation (ie, conjunctival injection, presence of keratic precipitates and intraocular signs) at the time of surgery for patients with FED was significant for developing rejection: 3.5 times greater compared with those with no inflammation (P = .02). Conclusions: There is no significant difference in rejection-free survival between EK and PK for FED or PBK. The presence of inflammation is an important risk factor, and attention to its control before and following surgery is important. [ABSTRACT FROM AUTHOR]

PURPOSE: To investigate graft survival and surgical experience on clinical outcome following deep anterior lamellar keratoplasty (DALK). DESIGN: Multicenter cohort study. METHODS: The United Kingdom Transplant Database was used to identify patients who had undergone a first DALK or penetrating keratoplasty (PKP) for keratoconus. Data were collected at the time of surgery and at 1, 2, and 5 years postoperatively. Graft survival, bestcorrected visual acuity, and refractive error were analyzed for 3 consecutive time periods. DALK outcomes were analyzed according to surgeon experience. RESULTS: A total of 4521 patients were included. Graft survival was 92% (95% CI: 90-92) for PKP and 90% (95% CI: 88-92) for DALK (P = .09). For corneal transplants undertaken in the periods 1999-2002, 2002-2005, and 2005-2007, graft survival was 90%, 92%, and 88% following DALK, and 93%, 91%, and 92% following PKP, respectively. There was no evidence of a difference between surgeons in terms of case mix (P = .4) or outcome (P = .2). Surgeon experience, in terms of the number of previous DALK undertaken, had no significant effect on outcome. A donor recipient trephine size disparity of 0.5 mm was associated with an increased risk of graft failure for both DALK (P = .03) and PKP (P = .002), whereas ocular surface disease was a significant risk factor for DALK (P = .04) but not PKP. CONCLUSIONS: There has been little change in graft survival for DALK and PKP over the past decade. Ocular surface disease is an important risk factor for graft failure following DALK. A surgical learning curve for DALK could not be demonstrated in terms of clinical outcome. [ABSTRACT FROM AUTHOR]

PURPOSE: To compare national outcomes of endothelial keratoplasty (EK) and penetrating keratoplasty (PK) during comparable 6-year periods. DESIGN: Prospective cohort study of national registry data. METHODS: SETTING: United Kingdom National Transplant Registry, 2000 through 2011, inclusive. PATIENT POPULATION: All United Kingdom patients undergoing first EK (n = 2074) for Fuchs endothelial dystrophy or pseudophakic bullous keratopathy from January 2006 through December 2011. Comparison cohort of patients undergoing first PK (n = 2622, same indications, January 2000 through December 2005). OBSERVATION PROCEDURE: Year of surgery, surgeon and center experience, corneal diagnosis, donor factors, patient factors, and surgical risk factors were analyzed against graft survival and visual outcomes. RESULTS: For both Fuchs endothelial dystrophy and pseudophakic bullous keratopathy, EK achieved better average best-corrected acuity and lower refractive error. For both groups, graft failure was significantly higher for EK than PK. EK failure in Fuchs endothelial dystrophy was associated with center experience (hazard ratio [HR], 2.3; P < .0001), donor endothelial density (HR, 1.8; P = .01), glaucoma at time of surgery (HR, 2.1; P = .003), and donor age older than 75 years (HR, 1.3; P = .05). EK failure in pseudophakic bullous keratopathy was associated with center experience of fewer than 15 cases (HR, 2.0; P < .0001) and glaucoma at time of surgery (HR, 1.7; P = .002). CONCLUSIONS: Prospective national registry data for EK showed higher graft failure than is seen in PK or in retrospective case series of EK. Higher failure rates may be acceptable given established benefits of the procedure, including lower refractive error, structural globe integrity, and faster visual recovery. Center experience influenced EK survival more than surgeon experience, and overall surgical outcomes may be improved by standardized techniques and support within experienced units. [ABSTRACT FROM AUTHOR]

Wetland ecosystems maintain and improve water quality through the process of denitrification, an increasingly important ecosystem service due to global N pollution. Invasive plants have the potential to disrupt denitrification by altering the environmental conditions that facilitate this process. Great Lakes coastal wetlands are experiencing widespread invasion by highly productive hybrid cattail with largely uncertain biogeochemical effects. Through field and controlled mesocosm studies, we sought to determine the effects of cattail invasion through time on denitrification rates and associated environmental factors in a Great Lakes coastal wetland. In the field, we found that cattail density correlated with increased denitrification and a suite of environmental and plant community characteristics and denitrification rates were positively correlated with NH, sediment organic matter, reduced water levels, and cattail stand age. Through our controlled mesocosm study, we documented conditions 1- and 5-year following invasion and found that denitrification rates and soil organic matter increased in year 5, and cattail and year-since-invasion altered plant communities and soil NH. Only a weak correlation between denitrification rates and cattail treatments was noted, however, owing to high replicate variability. Our results indicate that with increasing cattail residence time, one ecosystem service, biodiversity, was negatively impacted, while two other services, denitrification and sediment carbon accumulation, were enhanced. Thus, this highly invaded wetland still provides valuable services to aquatic ecosystems and to society. A holistic perspective is therefore critical when evaluating invasive species impacts in which negative impacts are weighed against other ecosystem services, which may be stimulated. [ABSTRACT FROM AUTHOR]

Understanding the phenology of the invasive macroalga Nitellopsis obtusa (starry stonewort) is critical for evaluating and predicting its impacts on native macrophytes and timing control efforts. We tracked N. obtusa phenology in two Minnesota (USA) lakes from 2017 to 2018. We measured N. obtusa biomass and counted bulbils (asexual reproductive structures) throughout the growing season and in winter, under ice. Additionally, we compared phenology of N. obtusa to other invasive and native macrophytes using a long-term, Minnesota statewide dataset. We found consistent late-season peaks in N. obtusa biomass in both lakes, and this extended growth distinguished it from common native and invasive macrophytes in the region. Phenological asynchrony of N. obtusa relative to native macrophytes indicates use of a distinct temporal niche that may contribute to its invasion success. Bulbil counts were lowest early to mid-summer and increased through fall; however, high variability in this relationship warrants more intensive sampling to clarify seasonal trends. Late-season growth of N. obtusa poses challenges for timing control efforts, as early-season treatments may be limited to avoid harming native species. Treatment during peak biomass, before peak bulbil abundance, may improve control. • Phenology of N. obtusa was similar among two lakes in Minnesota, USA. • Biomass of N. obtusa peaks later in the season than co-occurring species. • The extended growing season of N. obtusa may contribute to its invasive success. • Nitellopsis obtusa bulbil counts were lowest early/mid-summer, increased through fall. • Late-season growth of N. obtusa poses challenges for timing control efforts. [ABSTRACT FROM AUTHOR]

Previously we have shown that indoleamine 2,3-dioxygenase ( IDO) and the tryptophan metabolite, 3-hydroxykynurenine (3 HK) can prolong corneal allograft survival. IDO modulates the immune response by depletion of the essential amino acid tryptophan by breakdown to kynurenines, which themselves act directly on T lymphocytes. The tryptophan metabolite analogue N-(3,4-dimethoxycinnamonyl) anthranilic acid ( DAA, 'Tranilast') shares the anthranilic acid core with 3 HK. Systemic administration of DAA to mice receiving a fully MHC-mismatched allograft of cornea or skin resulted in significant delay in rejection (median survival of controls 12 days, 13 days for cornea and skin grafts, respectively, and of treated mice 24 days ( P < 0·0001) and 17 days ( P < 0·03), respectively). We provide evidence that DAA-induced suppression of the allogeneic response, in contrast to that induced by tryptophan metabolites, was a result of cell cycle arrest rather than T-cell death. Cell cycle arrest was mediated by up-regulation of the cell cycle-specific inhibitors p21 and p15, and associated with a significant reduction in interleukin-2 production, allowing us to characterize a novel mechanism for DAA-induced T-cell anergy. Currently licensed as an anti-allergy drug, the oral bioavailability and safe therapeutic profile of DAA make it a candidate for the prevention of rejection of transplanted cornea and other tissues. [ABSTRACT FROM AUTHOR]

Aims To assess whether topical steroids improve patient comfort compared with hypromellose in acute presumed viral conjunctivitis. Methods Patients presenting with acute follicular conjunctivitis, presumed viral in origin, were randomised to receive either dexamethasone 0.1% or hypromellose 0.3% drops four times daily for 1 week. At review after 5e7 days patients completed questionnaires on whether they thought the treatment had helped and on their level of discomfort. A physician assessed conjunctival hyperaemia using a grading scale. Results 111 patients were randomised: 56 received dexamethasone drops and 55 received hypromellose lubricant drops. Eighty-eight returned for review. Most patients (39/45 (87%)) receiving dexamethasone and most of those receiving hypromellose 30/43 (70%) felt that the treatment helped. Analysis of all responses showed a significant difference between treatments (p=0.0248, rank sum test). No significant differences between dexamethasone and hypromellose arms were found in the patients' perceived level of discomfort or the physician grading of conjunctival hyperaemia. No patient experienced a serious complication. Conclusions There us now evidence to support the use of a short course of topical dexamethasone for patients presenting with acute follicular conjunctivitis presumed to be viral in origin. Where topical dexamethasone is prescribed we have not found it to be harmful. [ABSTRACT FROM AUTHOR]