Long-term nitrogen deposition reduces the diversity of nitrogen-fixing plants.

Biological nitrogen fixation is a fundamental part of ecosystem functioning. Anthropogenic nitrogen deposition and climate change may, however, limit the competitive advantage of nitrogen-fixing plants, leading to reduced relative diversity of nitrogen-fixing plants. Yet, assessments of changes of nitrogen-fixing plant long-term community diversity are rare.

Combining multiple investigative approaches to unravel functional responses to global change in the understorey of temperate forests.

Plant communities are being exposed to changing environmental conditions all around the globe, leading to alterations in plant diversity, community composition, and ecosystem functioning. For herbaceous understorey communities in temperate forests, responses to global change are postulated to be complex, due to the presence of a tree layer that modulates understorey responses to external pressures such as climate change and changes in atmospheric nitrogen deposition rates. Multiple investigative approaches have been put forward as tools to detect, quantify and predict understorey responses to these global-change drivers, including, among others, distributed resurvey studies and manipulative experiments.

Failure to purge: population and individual inbreeding effects on fitness across generations of wild Impatiens capensis.

Inbreeding exposes deleterious recessive alleles in homozygotes, lowering fitness and generating inbreeding depression (ID). Both purging (via selection) and fixation (via drift) should reduce segregating deleterious mutations and ID in more inbred populations. These theoretical predictions are not well-tested in wild populations, which is concerning given purging/fixation have opposite fitness outcomes.

Divergent roles of herbivory in eutrophying forests.

Ungulate populations are increasing across Europe with important implications for forest plant communities. Concurrently, atmospheric nitrogen (N) deposition continues to eutrophicate forests, threatening many rare, often more nutrient-efficient, plant species. These pressures may critically interact to shape biodiversity as in grassland and tundra systems, yet any potential interactions in forests remain poorly understood.

Plastic and quantitative genetic divergence mirror environmental gradients among wild, fragmented populations of Impatiens capensis.

Premise: Habitat fragmentation generates molecular genetic divergence among isolated populations, but few studies have assessed phenotypic divergence and fitness in populations where the genetic consequences of habitat fragmentation are known. Phenotypic divergence could reflect plasticity, local adaptation, and/or genetic drift.

Methods: We examined patterns and potential drivers of phenotypic divergence among 12 populations of jewelweed (Impatiens capensis) that show strong molecular genetic signals of isolation and drift among fragmented habitats.

Evaluation of the novel vaginal contraceptive agent PPCM in preclinical studies using sperm hyaluronan binding and acrosome status assays.

Background: Polyphenylene carboxymethylene (PPCM) sodium salt is a promising multipurpose technology for prevention of both sexually transmitted infections (STIs) and pregnancy. In preclinical studies, PPCM has demonstrated significant (1) antimicrobial activity against several important viral and bacterial pathogens and (2) contraceptive activity associated with premature acrosome loss.

Objective: To further evaluate a vaginal antimicrobial compound as a contraceptive agent in preclinical studies utilizing a repurposed hyaluronan binding assay (HBA).

Stresses affect inbreeding depression in complex ways: disentangling stress-specific genetic effects from effects of initial size in plants.

The magnitude of inbreeding depression (ID) varies unpredictably among environments. ID often increases in stressful environments suggesting that these expose more deleterious alleles to selection or increase their effects. More simply, ID could increase under conditions that amplify phenotypic variation (CV²), e.

Addressing Darwin's dilemma: Can pseudo-overdominance explain persistent inbreeding depression and load?

Darwin spent years investigating the effects of self-fertilization, concluding that "nature abhors perpetual self-fertilization." Given that selection purges inbred populations of strongly deleterious mutations and drift fixes mild mutations, why does inbreeding depression (ID) persist in highly inbred taxa and why do no purely selfing taxa exist? Background selection, associations and interference among loci, and drift within small inbred populations all limit selection while often increasing fixation. These mechanisms help to explain why more inbred populations in most species consistently show more fixed load.

Shifts in precipitation and agricultural intensity increase phosphorus concentrations and loads in an agricultural watershed.

Fertilizers and manure applied to cropland to increase yields are often lost via surface erosion, soil leaching, and runoff, increasing nutrient loads in surface and sub-surface waters, degrading water quality, and worsening the 'dead zone' in the Gulf of Mexico. We leverage spatial and temporal variation in agricultural practices and precipitation events to examine how these factors affect stream total phosphorus (TP) concentrations and loads in the Sugar River (Wisconsin), recently listed as impaired. To perform our analysis, we first collected water quality data from 1995 to 2017 from 40 sites along the Sugar River and its tributaries.

Adaptive associations among life history, reproductive traits, environment, and origin in the Wisconsin angiosperm flora.

Premise: We tested 25 classic and novel hypotheses regarding trait-origin, trait-trait, and trait-environment relationships to account for flora-wide variation in life history, habit, and especially reproductive traits using a plastid DNA phylogeny of most native (96.6%, or 1494/1547 species) and introduced (87.5%, or 690/789 species) angiosperms in Wisconsin, USA.

Development of multipurpose technologies products for pregnancy and STI prevention: update on polyphenylene carboxymethylene MPT gel development†.

Current modern contraceptives rely heavily on the use of hormones. These birth control drug products, including pills, patches, injections, and IUDS, have been extremely beneficial to millions of women and their families over the past 50 years. But a surprisingly high number of women abandon such modern methods, many because they cannot tolerate the side effects and others because they have medical issues for which hormonal methods are contraindicated.

Drift happens: Molecular genetic diversity and differentiation among populations of jewelweed (Impatiens capensis Meerb.) reflect fragmentation of floodplain forests.

Landscape features often shape patterns of gene flow and genetic differentiation in plant species. Populations that are small and isolated enough also become subject to genetic drift. We examined patterns of gene flow and differentiation among 12 floodplain populations of the selfing annual jewelweed (Impatiens capensis Meerb.

Spatial phylogenetics reveals evolutionary constraints on the assembly of a large regional flora.

Premise Of The Study: We used spatial phylogenetics to analyze the assembly of the Wisconsin flora, linking processes of dispersal and niche evolution to spatial patterns of floristic and phylogenetic diversity and testing whether phylogenetic niche conservatism can account for these patterns.

Methods: We used digitized records and a new molecular phylogeny for 93% of vascular plants in Wisconsin to estimate spatial variation in species richness and phylogenetic α and β diversity in a native flora shaped mainly by postglacial dispersal and response to environmental gradients. We developed distribution models for all species and used these to infer fine-scale variation in potential diversity, phylogenetic distance, and interspecific range overlaps.

Understanding context dependency in the response of forest understorey plant communities to nitrogen deposition.

Understorey communities can dominate forest plant diversity and strongly affect forest ecosystem structure and function. Understoreys often respond sensitively but inconsistently to drivers of ecological change, including nitrogen (N) deposition. Nitrogen deposition effects, reflected in the concept of critical loads, vary greatly not only among species and guilds, but also among forest types.