Biological invasions pose a serious threat to biodiversity, but monitoring for invasive species is time consuming and costly. Understanding where species have the potential to invade enables land managers to focus monitoring efforts. In this paper, we compared two simple types of models to predict the potential distributions of three non-native invasive plants (Geranium robertianum, Hedera spp., and Ilex aquifolium) in the contiguous USA. We developed models based on the climatic requirements of the species as reported in the literature (literature-based) and simple climate envelope models based on the climate where the species already occur (observation-based). We then compared the results of these models with the current species distributions. Most models accurately predicted occurrences, but overall accuracy was often low because these species have not yet spread throughout their potential ranges. However, literature-based models for Geranium and observation-based models for Ilex illustrated potential problems with the methodology. Although neither model type produced accurate predictions in all cases, comparing the two methods with each other and with the current species distributions provided rough estimates of the potential habitat for each species. More importantly, this methodology raised specific questions for further research to increase our understanding of invasion patterns of these species. Although these types of models do not replace more rigorous modeling techniques, we suggest that this methodology can be an important early step in understanding the potential distributions of non-native species and can allow managers of natural areas to be aware of potential invaders and implement early detection.

California endemic vascular plant range patterns were quantified using a flora-based geodatabase technique that defined species range by geographic area and elevation band. Resulting species spatial patterns are reported for 228 geographic units. Over 60% of the endemic species range size distributions were found to have range sizes less than 10,000 km². The largest endemic taxon range was 275,749 km², or 67% of the state. California endemic plant richness distribution patterns are summarized by 228 geographic units, and reported by various criteria. California's Central Coast Ranges, Sierra Nevada foothills, high elevation Sierra Nevada Mountains, Channel Islands, San Jacinto Mountains, Napa and Lake Counties, Inyo Mountains, sections of the Mojave Desert, and San Bernardino Mountains were all identified as areas with unique endemic plant attributes. We compared endemic species richness between map units in zones containing similar topography and climate, and found that area only weakly correlated with species richness, suggesting other factors have stronger influence on endemism in continental California. The findings have implications for developing conservation plans that target endemic species. In particular, we identify areas of the state, previously de-emphasized, that deserve greater recognition based on the characteristics of their restricted endemic plants. This analysis underestimates the level of endemism near the borders with Oregon and Baja California because of the artificial limitation of the database to the boundaries of the state of California. However, range distribution estimates produced from digital renditions of floral keys proved effective in this study, an inexpensive approach that could be implemented in other regions of the world for which floras have been published.

Craggy Gardens, a Southern Appalachian grass/heath bald in western North Carolina, is experiencing Quercus rubra L. encroachment on the western slope. Grass balds provide habitat for a number of rare and endemic species and have been ranked by The Nature Conservancy as G1 (Critically Imperiled Globally). We used belt transects and dendroecological analysis to reconstruct Quercus rubra establishment and recruitment over the past 245 years. Tree-ring records from 128 trees yielded distinct spatial and temporal patterns of encroachment that appear to be explained in large part by historical land use. Grazing by European livestock suppressed tree establishment, and its cessation in the early 1930s facilitated tree establishment and recruitment. Reduced rates of tree encroachment after the 1960s appear to be linked to shading of the understory upon canopy closure after the initial surge of establishment. Tree encroachment declined significantly after 1980, and was followed by the initiation of an ecological restoration project aimed at maintaining the grass bald at Craggy Gardens to preserve rare and endangered species and scenic appeal. Active management has reintroduced a strong human influence on the successional development of the bald.

The Center for Plant Conservation (CPC) has created sampling guidelines for the ex situ conservation of rare plant species. These guidelines estimate the number of individuals needed to maximize the genetic diversity of the collection according to population genetic theory. For many clonal plant species, knowledge of the number of unique individuals is not easily discerned and application of these guidelines must be based on molecular genetic data. In this paper, we discuss the steps taken in order to meet CPC guidelines for the conservation of a rare clonal plant, Clematis socialis. Due to limited seed availability, methods were developed for successful in vitro propagation and cryopreservation of C. socialis shoot tips. Inter-simple sequence repeat (ISSR) analysis identified fifteen unique genotypes in the ex situ in vitro collection. One genotype in this collection has been conserved from a population that is now presumed extinct. Although the initial sampling protocol managed to capture considerable genetic diversity, an additional 97 genotypes are needed to meet CPC guidelines. The information and experience gained through the initial C. socialis ex situ conservation efforts form the basis for a strategy to improve ex situ conservation activities for this endangered species. We recommend that additional in vitro collections be made from each of the five extant populations and placed in cryostorage.

Climate warming is predicted to cause boreal forests in the Boundary Waters Canoe Area Wilderness (BWCAW), Minnesota, to shift to savanna and/or temperate forest in the next century. Invasive earthworms, exotic tree pests, and deer overabundance will magnify the impacts of warmer temperatures. Seldom do we assess potential threats to ecosystem and wilderness integrity in a systematic way and develop policy and management strategies ahead of time to mitigate the situation. Debates on several issues involving wilderness users, managers, and scientists need to be resolved for the BWCAW. These include whether, when, and how to: (1) use fire; (2) restore tree species to wilderness areas lost through human actions (e.g., logging of white pine (Pinus strobus L.) that occurred before wilderness designation and potential loss of ash species from the introduced pest emerald ash borer (Agrilus planipennis Fairmaire)); (3) manage the potential overabundance of deer that threaten reproduction of some tree species; (4) facilitate (or prevent) migration of new tree species currently native south of the wilderness; (5) employ local (within wilderness) or regional assisted migration for species that cannot migrate fast enough on their own to keep up with climate change; and (6) manage invasive species. Some of these activities would not be allowed under the wilderness laws of 1964 and 1978, and may be difficult to enact or limited in effectiveness. Major change in forests of the BWCAW is a certainty, and facilitation of a ‘graceful transition’ to native species rather than exotic species is desirable.

Protected area managers should aim to help the greatest number of species and habitats that presently occur within their parks to adapt and persist in the face of climate change, and ensure that the novel ecosystems that emerge are diverse and resilient. A practical and cost-effective approach to achieve these goals is to focus management efforts on habitat corridors along natural environmental gradients (that is, adaptation corridors embedded within larger natural landscapes) and keystone habitats that provide critical resources within existing protected areas.