North America's remaining natural grassland communities provide habitat for native flora and fauna. We conducted a study to compare the efficacy of herbicides in control of the invasive Japanese honeysuckle (Lonicera japonica Thunb.) applied at times when most native plant species are dormant. Six herbicide mixtures (glyphosate, glyphosate imazapyr, glyphosate imazapic, imazapyr, triclopyr diflufenzopyr, and metsulfuron methyl diflufenzopyr) were applied once each in three seasons to assess the effect of application timing of each mixture on honeysuckle control. Herbicides were applied with a CO₂ pressurized sprayer at three sites in a randomized complete block design. Pretreatment sampling indicated that Japanese honeysuckle constituted over 70% of plant cover at the study sites. Post-treatment sampling was conducted 60 days, 180 days, 420 days, and 540 days after the final application. All mixtures in all application seasons decreased percent cover of honeysuckle with varying effectiveness. Results indicate that the glyphosate, imazapyr, and metsulfuron methyl diflufenzopyr mixtures are particularly effective at controlling Japanese honeysuckle when applied at any time between October and April with suitable temperatures. Many native grasses and broadleaf forbs not found during pretreatment sampling also emerged post-treatment, benefiting from either application timing or indicating herbicide tolerance.

Population introduction is frequently attempted to promote rare plant conservation but there is little evidence to evaluate its effectiveness. We measured size structure, survival, growth, and recruitment in three 20-year-old introduced populations of the endangered shrub Conradina glabra, an endemic in upland longleaf pine habitat in the Florida Panhandle, and compared these with measurements from three natural populations. We also quantified inbreeding depression from hand pollinations in two populations and incorporated its consequences for seed production and germination into demographic projections. Individuals in introduced populations, which had been subjected to recent prescribed fire, grew nearly three times faster and produced more than twice as many recruits per individual, but suffered 3.7% greater mortality than individuals in wild populations growing in habitat where fire was suppressed. Demographic matrix projections based on our data predict that introduced populations would grow at least as fast as the naturally occurring populations. Inbreeding depression was strong (δ = 0.887, 0.65 in one introduced and one wild population, respectively) but was predicted to threaten population growth rates only if selfing were to increase substantially. Our results, along with previous evidence for population growth after the initial introductions and persistence for over 25 years, illustrate the potential for well-designed introduction combined with appropriate management to contribute to rare plant conservation.

Castle Mound Pine Forest State Natural Area (CMPF) is a 48-ha reserve at the confluence of the Driftless Area and Central Sand Plains of Wisconsin. Here, we report the first tree-ring—based fire history study for central Wisconsin and examine the relationships among fire, forest structure and composition, and historical land use at the site. We crossdated 12 fire-scar samples from Pinus resinosa stumps and inventoried and cored 83 trees along four transects to quantify the fire history, forest composition, and forest age structure at the site. The fire history data span the years 1788–2006 and include 15 years when trees were scarred by a fire on the site. Most fire scars were recorded in the earlywood of the recording growth ring, suggesting spring or early summer fires. The mean fire return interval for the site was six years when calculated between the first fire in 1841 and the last fire in 1923. The time-since-fire at the time of our study was 91 years. The canopy of the site was dominated by P. resinosa, individuals of which represent the oldest trees on the site. The subcanopy and recent age structure was dominated by mesic species, indicating that the forest at CMPF is transitioning away from the historical dominance by P. resinosa to a more closed forest following the cessation of fire at the site. Our data highlight an opportunity to establish ecological baseline data for this area to inform fire management and restoration activities.

Patch-burn grazing is a grassland management approach that recouples the processes of fire and grazing altering animal distribution and creating structural heterogeneity for the benefit of flora and fauna biodiversity. Our objective was to investigate the effects of patch-burn grazing on plant species composition in tallgrass prairie remnants on conservation lands in Missouri. Each grazed unit consisted of three patches with each patch approximately one-third the size of the grazed unit. We burned a different patch annually and stocked the entire unit at a moderate rate of 0.45 AUM/ha with yearling stocker steers. We established paired plots of treatment (grazed) and control (grazing excluded) and sampled vegetative composition during a 3-yr graze-burn cycle and a fourth year of no treatments. Species richness, diversity, and floristic quality of exclosures were compared between plots using the Shannon, Simpson, and Floristic Quality indices. Our results indicated a year × treatment interaction. Specifically, species richness and floristic quality were significantly reduced in grazed plots during the first growing season post-burn (P < 0.05). However, after the first growing season post-burning and focal grazing, grazed plots no longer differed in diversity or floristic quality from ungrazed plots. Species richness remained elevated in grazed plots beyond the first growing season after burning and focal grazing. Species diversity showed no significant change in grazed plots throughout the study (P < 0.05) but results indicated a similar trend, declining during the first growing season post-burn followed by a spike the second year and recovery in subsequent years. More research is necessary to understand effects of long-term implementation of patch-burn grazing and on individual species. Despite the results of a companion study on horizontal structure, our results suggest that after one year of intense grazing following fire, any changes in vegetative composition were minor to nonexistent after three years of patch-burn grazing and one year of rest

Snowmobiling in Congressionally designated Wilderness (CW) in Alaska is a contentious issue in the arena of appropriate use of public lands. The 1980 Alaska National Interests Lands Conservation Act allows snowmobiling in CW for traditional activities. Conversely, the 1964 Wilderness Act prohibits motor vehicles in CW to preserve its naturalness and opportunities for solitude. These conflicting mandates challenge the ability of managers to preserve CW character. The Kenai National Wildlife Refuge (KENWR) manages 534,300 ha of CW, where 253,200 ha are open to snowmobiling. Snowmobile noise degrades CW character whereas natural quiet is indicative of naturalness and offers opportunities for solitude. We determined the acoustic footprint of snowmobile noise and areas of natural quiet refugia in CW by recording the soundscape at 27 locations inside, and 37 locations outside, KENWR CW. We calculated soundscape power (normalized watts/kHz) from 59,598 sound recordings and generated spatially explicit models of snowmobile noise and natural quiet using machine-learning (TreeNet). We calculated the area of CW with the highest and lowest soundscape power for snowmobile noise and natural quiet, respectively. Snowmobile noise occurred during daylight hours while natural quiet was predominant at night. Snowmobile noise was higher in February and March while January was quieter. Snowmobile noise affected 39% of CW open to snowmobiling while natural quiet made up 36%. Natural quiet occurred in 51% of all KENWR CW of which 39% was prohibited by management or inaccessible by snowmobiles. Our models identify areas where conservation of winter soundscapes in CW can be focused.

Light pollution has been of increasing concern as it relates to protected areas. As such, natural resource managers need information on the distribution, intensity, and dynamics of nighttime lights in protected areas. We examine the extent of nighttime light brightness from 1992 to 2012 in the Mediterranean Coast Network (Santa Monica Mountains National Recreation Area, Channel Islands National Park, and Cabrillo National Monument) using the Defense Meteorological Satellite Program (DMSP) Operational Linescan System, which has provided global annual nighttime light imagery at 0.9 km pixel resolution. Nighttime lights appeared stable in Santa Monica Mountains National Recreation Area, decreased in Cabrillo National Monument, and are extremely low in Channel Islands National Park. However, the mean brightness values in Santa Monica Mountains National Recreation Area and Cabrillo National Monument were very high compared to all other National Parks. Indeed, both were comparable to the two National Parks in the USA with the highest mean brightness values (Cuyahoga Valley National Park, Hot Springs National Park). Monitoring night light extent, intensity, time series, and change detection using remote sensing should be a standard practice for all protected areas managed by the National Park Service due to the no-cost nature of the data and ease at which analyses can be undertaken. The DMSP data and calibrated products can be used to monitor long-term changes in light distribution and intensity while the higher-resolution Visible Infrared Imaging Radiometer Suite data can be used to show changes in light distribution and density throughout the year and can be used to test how policy or ordinance changes impact light pollution.

We collected plant phenology data in the Sapphire Mountains, Montana, USA, by monitoring developmental stages of 101 native species and 21 exotic species during weekly visits to the sites from March to November 2013. We compared the start, end, and length of the emergence, flowering, and seed maturation phases for exotic and native plants. Short-lived forbs, perennial forbs, and perennial grasses were analyzed separately. Exotic plants emerged earlier, began and ended flowering later, and had later ends to emergence and dispersal phases across all functional group comparisons. The emergence phase for exotic perennial forbs averaged 13.8 weeks longer than for native perennial forbs, the flowering phase was 3.4 weeks longer, and the seed dispersal phase was 8.3 weeks longer. The window for emergence and flowering for forbs, shrubs, and grasses (March to November) did not differ between natives and exotics. The results generally support the conclusion that the exotics have an advantage over the natives in priority of growth and wider niche breadth, rather than occupying vacant niches. Seed set time varied in duration from 1 to 23 weeks from April to November. Our results provide insights into invasion mechanisms and selection of native plant materials to compete with invasive species. We discuss implications for seed collection and herbicide timing.

Slender rush-pea (Hoffmannseggia tenella) is an endangered herbaceous legume endemic to southern Texas. Agricultural expansion and invasive nonnative grasses have caused reductions in its range, threatening existing populations. We compared three management techniques that control competition to no management (control) to determine effects on slender rush-pea survival and morphology. We treated some slender rush-pea plants with summer prescribed burning. In the mechanical treatment we controlled above-ground competition surrounding target slender rush-pea plants with a string trimmer and we removed both above- and below-ground competition with herbicide in the chemical treatment. No slender rush-pea plants died during our two-year study. Plants in each competition removal treatment produced more main stems than control plants at various times throughout the study. Summer prescribed burning produced longer stems, while both summer burning and chemical treatment resulted in more leaves on the longest stem and more flowers than control plants at various times throughout the study. Slender rush-pea individuals with more main stems, longer stems, and more leaves may be more robust and resilient to environmental stress. We speculate increased flower production may indicate enhanced reproduction. At the pasture scale herbicide treatment is not practical as it may eradicate remaining native plants. Summer prescribed burning may be the most effective method for increasing short-term robustness of slender rush-pea; mowing could be a temporary substitute when fire is impractical. Results indicate that slender rush-pea benefits from active management and control of competition from nonnative grasses, and if managed properly slender rush-pea could persist in their presence.

Many eastern forest communities depend on fire for regeneration or are enhanced by fire as a restoration practice. However, the use of prescribed fire in the mesic forested environments and the densely populated regions of the eastern United States has been limited. The objective of our research was to develop a science-based approach to prioritizing the use of prescribed fire in appropriate forest types in the eastern United States based on a set of desired management outcomes. Through a process of expert elicitation and data analysis, we assessed and integrated recent vegetation community mapping results along with other available spatial data layers into a spatial prioritization tool for prescribed fire planning at Shenandoah National Park (Virginia, USA). The integration of vegetation spatial data allowed for development of per-pixel priority rankings and exclusion areas enabling precise targeting of fire management activities on the ground, as well as a park-wide ranking of fire planning compartments. We demonstrate the use and evaluation of this approach through implementation and monitoring of a prescribed burn and show that progress is being made toward desired conditions. Integration of spatial data into the fire planning process has served as a collaborative tool for the implementation of prescribed fire projects, which assures projects will be planned in the most appropriate areas to meet objectives that are supported by current science.

The invasive emerald ash borer (Agrilus planipennis) (EAB) is causing widespread ash (Fraxinus spp.) mortality in 25 U.S. states and two Canadian provinces. We investigated the impact of EAB on coarse woody debris (CWD) volume across 24 sites in western and central Ohio, USA, representing a chronosequence of ash mortality, quantified by the year ash mortality reached 25% (Year25�ad). CWD volume averaged 60.36 m³/ha, and was positively associated with total (live plus dead) ash basal area (BA), but was not greater in sites where ash death occurred earlier. For the volume of CWD in the first, least-rotted, decay class, stepwise regression revealed that both ash BA and Year25�ad were significant predictors; sites with more ash BA and where ash mortality had occurred earlier had more class 1 CWD. Additionally, class 1 CWD in those early mortality sites was primarily (87%) ash, compared to 40% ash in sites with more recent ash mortality. This large influx of CWD, particularly ash CWD, combined with future inputs from ash that are still standing, will elevate CWD volume in the near future, especially in sites with greater ash basal area.

Willow (Salix spp.) stakes are used in riparian restoration due to their wetland adaptations, large root systems, and production of adventitious roots. Best practices for maximizing stake performance need to be developed. We tested the effects of storage, scoring, and auxin treatments on the performance of sandbar willow (Salix exigua) stakes. Storage significantly increased height, longest stem length, and biomass. Height and aboveground biomass increased when stakes were stored/soaked. There were no significant effects of scoring or auxin application. Results show storing and soaking significantly improve willow stake performance, which could lead to faster canopy closure and better invasive species control in the field, increasing restoration success.