Imazapic has shown potential to control invasive weeds, such as cheatgrass (Bromus tectorum L.), during ecological restoration, but effects on non-target native plants are poorly known. In a replicated field experiment, as part of restoration for Gunnison sage-grouse (Centrocercus minimus) in Colorado, imazapic was applied in the fall at a high rate (175 g/ha) to control cheatgrass in mowed Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle & Young). Cheatgrass was reduced, but only by 67%, and non-native forbs were reduced by 80% by the following summer. However, native forbs also declined (by 84%). Two native grasses declined, but others were not affected. Damage to native forbs would likely be detrimental to sage-grouse and other wildlife if it occurred over large areas. Perhaps application of imazapic just to cheatgrass plants or patches and application earlier in restoration would allow control with less adverse effects on native forbs.

We examined effects of a natural disturbance (hurricanes) on potential invasion of tree islands by an exotic plant (Old World climbing fern, Lygodium microphyllum) in the Arthur R. Marshall Loxahatchee National Wildlife Refuge, Florida. Three major hurricanes in 2004 and 2005 caused varying degrees of impacts to trees on tree islands within the Refuge. Physical impacts of hurricanes were hypothesized to promote invasion and growth of L. microphyllum. We compared presence and density of L. microphyllum in plots of disturbed soil created by hurricane-caused treefalls to randomly selected non-disturbed plots on 12 tree islands. We also examined relationships between disturbed area size, canopy cover, and presence of standing water on presence and density of L. microphyllum. Lygodium microphyllum was present in significantly more treefall plots than random non-treefall plots (76% of the treefall plots (N=55) and only 14% of random non-treefall plots (N=55)). Density of L. microphyllum was higher in treefall plots compared to random non-disturbed plots (6.0 stems per m² for treefall plots; 0.5 stems per m² for random non-disturbed plots), and L. microphyllum density was correlated with disturbed area size (P = 0.005). Lygodium microphyllum presence in treefall sites was significantly related to canopy cover and presence of water: it was present in five times more treefalls with water than those without. These results suggest that disturbances, such as hurricanes, that result in canopy openings and the creation of disturbed areas with standing water contribute to the ability of L. microphyllum to invade natural areas.

We assessed the current status and potential future development of the only Atlantic white-cedar (Chamaecyparis thyoides) population in Pennsylvania (Spruce Flats Bog in Westmoreland County). We counted all stems in the population and measured the diameter at breast height of all stems ≥ 1.4 m in height. Increment cores were collected and analyzed from 93 trees to quantify age distribution. We also evaluated relationships among cedar regeneration, microtopography, and other potentially competitive vegetation. Potential recruitment from the seed bank was assessed via the germination method using soil samples from 46 hummocks in the bog. The population consisted of 395 stems with stem size structure characterized by an “inverse-J” distribution; most stems (67%) were < 1.4 m in height. The oldest individuals were established in the 1940s, but recruitment has been steady since initial establishment. Hummock area and mean height above the water table were positively related to the abundance of C. thyoides. No C. thyoides seeds germinated from soil samples during a 14-month period, indicating that the bog's seed bank may have limited potential to contribute to recruitment. We suggest that this population has naturalized from plantings in the 1940s, with most recent recruitment having been vegetative. Because of previous extirpation of C. thyoides from Pennsylvania wetlands, the naturalization of this population has conservation value. Although the population size is probably limited by the number of microsites sufficiently high above the water table to avoid excessive inundation, direct management of this population does not currently appear to be necessary in order to ensure its continued survival.

Using a dataset of special status animal species aggregated from NatureServe (2006), we assessed the conservation significance of the newest U.S. network of protected areas, the BLM-administered National Landscape Conservation System (NLCS) composed of ∼11 million hectares of specially designated conservation areas. We examined the number of special status animal species that occur within the NLCS as compared to the number that would be predicted by area alone, occurrences within the NLCS as compared to other BLM lands, and the conservation implications of these species-area relationships. Our analyses suggest that the NLCS plays a significant role in the conservation of special status species and the natural ecosystems on which they depend.

Understory plant composition and diversity levels in oak-hickory (Quercus-Carya) forests have historically been maintained by periodic low-intensity ground fires, but fire suppression has altered the structure and function of these communities. We examined burned and unburned oak-hickory stands to determine the influence of repeated burning on understory communities. We compared understory herbaceous, shrub, and tree species diversity and composition among four burn categories: unburned stands, and stands that had burned once, twice, and three times over a 20-year period (late 1960s to late 1980s). We hypothesized that stands that have received repeated burns will have greater understory diversity and reduced importance of shade-tolerant mesophytic species. We found that burned stands had greater species richness than unburned stands, regardless of burn frequency. Species composition was not drastically different among the four burn categories; however, individual species were indicative of particular burn categories. More forest herbs were associated with the single burn category, while more disturbance-dependent species (Desmodium spp. and Solidago spp.) were associated with the repeated burn categories. Burned stands contained greater densities of white oak (Quercus alba L.) and hickory species seedlings. Our results suggest that restoring and maintaining the historic fire return interval (10–15 years) will promote herbaceous species diversity and favor the regeneration of oak and hickory species. However, it has been 15–22 years since the stands we sampled last burned, and the similarity among burn categories suggests that additional burning is needed to prevent these stands from reverting to a suppressed condition.

This study examined efforts to promote species establishment and maintain diversity in a Phragmites-dominated wetland where primary control measures were underway. A treatment experiment was performed at Crane Creek, a drowned-river-mouth wetland in Ottawa National Wildlife Refuge along the shore of western Lake Erie. Following initial aerial spraying of Phragmites with glyphosate, this study tested combinations of cutting, raking, and additional hand spraying of Phragmites with glyphosate as methods to promote growth of other wetland species and increase plant diversity. Percent-cover vegetation data were collected in permanent plots before and after treatments, and follow-up sampling was performed the following year. Increased species richness, species emergence, and relative dominance of non-Phragmites taxa were used as measures of treatment success. We also examined treatment effects on Phragmites cover. Dimensionality of seedbank and soil properties was reduced using principal component analysis. With the exception of nitrogen, soil nutrients affected species establishment, non-Phragmites taxa dominance, and Phragmites cover. A more viable seedbank led to greater species emergence. Treatments had differential effects on diversity depending on elevation and resulting degree of hydrologic inundation. Whereas raking to remove dead Phragmites biomass was central to promoting species establishment in dry areas, spraying had a greater impact in continually inundated areas. For treatment success across elevations into the year following treatments, spraying in combination with cutting and raking had the greatest effect. The results of this study suggest that secondary treatments can produce a short-term benefit to the plant community in areas treated for Phragmites.

Regional distribution and abundance data for invasive plant species are urgently needed for management planning, modeling of invasion risks and impacts, and communicating the scope of the problem. Yet, regional distribution data are rare in the United States. Here, we present a web-based mapping tool designed for efficient collection of expert opinion of invasive species abundance. We use this approach to generate distribution maps of three prominent invasive plants in the southeastern United States: (1) Chinese/European privet (Ligustrum sinense/vulgare), (2) kudzu (Pueraria montana), and (3) cogongrass (Imperata cylindrica). We validated the maps for internal consistency, based on multiple submissions for the same location, and with two other independent data sources: the U.S. Forest Service's Forest Inventory and Analysis plots (FIA) (for privet) and point-location data gathered from various sources (for all three species). Percent cover data were collected for each species across 30% of the Southeast U.S. The web-based mapping system yielded high participation rates (187 users). Internal consistency was 69% for Chinese/European privet, 72% for kudzu, and 88% for cogongrass. For Chinese/European privet, percent cover accuracy was 64% relative to the U.S. Forest Service FIA data. A web-based mapping system is an effective means of collecting regional distributional data from a broad but loose network of experts. Regional abundance maps complement point presence data typically used in invasive plant management. Regional distribution maps are useful for cross-jurisdictional management of invasive species, biogeographical research, and attracting support for containment and restoration programs.

An important component of many fens is large mounds created by ants for nesting purposes. Because these mounds differ in microtopography, hydrology, and soil characteristics from the surrounding fen, they have the potential to strongly influence fen vegetation. This study examined the effects of ant mounds on plant cover and species composition in two vegetation types within a Michigan prairie fen complex. Vegetation was sampled on ant mounds and in control plots in sedge meadow and shrub carr vegetation types. Total plant cover was significantly greater on ant mounds than in control plots in the sedge meadow, but significantly lower on ant mounds than in control lots in the shrub carr. Plants varied in their response to ant mounds as a function of their wetland indicator status. Both facultative upland and facultative species occurred more frequently on mounds, whereas obligate wetland species were more common in control plots. There was no significant difference for facultative wetland species. Plant life form also strongly influenced patterns of distribution on mounds vs. control plots, with grasses occurring more frequently on mounds, and forbs and sedges occurring less frequently on mounds than in control areas. Thus, especially in the sedge meadow, ant mounds provide an important refuge for species more adapted to dry conditions.

Southern old-growth forests are small and rare, but critical in their support of biodiversity. While the remnant old-growth forests contain diversity that is significant regionally and globally, they most likely represent only a portion of the variety that old forests once sustained. High within-habitat diversity and rarity in the landscape magnify the conservation value of these systems. Old-growth stands of two particular communities—longleaf pine (Pinus palustris) forests and floodplain (bottomland/swamp) forests—have emblematic links to two notable bird species of concern, the Red-cockaded (Picoides borealis) and Ivory-billed (Campephilus principalis) Woodpeckers. In addition to conservation importance, southern old forests have social and economic values that are in danger of further impoverishment if these systems are lost to future generations. Summarizing the findings from a recenatus and values, identify current threats, and describe potential strategies to promote greater long-term conservation of old forests across the South.

Relocating populations of philopatric turtle species is a relatively rare method used for species conservation that has had equivocal results. The purpose of this study is to report on the status of a population of ornate box turtles, Terrapene ornata ornata Agassiz, that was introduced into a restored tallgrass prairie habitat 160 km from its native location. From 1998–2003, a total of 56 individual turtles and one nest were collected from their natal habitat and were released into either a 5-ha or 1.75-ha enclosure. Most of the turtles were scute marked prior to release to facilitate recognition of specific individuals. In 2006–07, we resampled the population to determine if any turtles survived the relocation, if any local reproduction could be detected, and if specific microhabitats were being selected. We captured 14 T. ornata ornata, 11 of which were definitively part of the original turtle introduction. Three juvenile turtles were found and aged to be 5 years, suggesting local reproduction is occurring on site. Finally, although some turtles move through the prairie habitat throughout the fall season, only a small sandy microhabitat was used for hibernating. Our results suggest that relocating ornate box turtle populations to avoid mortality can be used as a successful conservation practice provided that the individuals are first released into a confinement to restrict their philopatric instincts.