The distribution and abundance of human-caused disturbances vary greatly through space and time and are cause for concern among land stewards in natural areas of the southwestern border-lands between the USA and Mexico. Human migration and border protection along the international boundary create Unauthorized Trail and Road (UTR) networks across National Park Service lands and other natural areas. UTRs may cause soil erosion and compaction, damage to vegetation and cultural resources, and may stress wildlife or impede their movements. We quantify the density and severity of UTR disturbances in relation to soils, and compare the use of previously established targeted trail assessments (hereafter — targeted assessments) against randomly placed transects to detect trail densities at Coronado National Memorial in Arizona in 2011. While trail distributions were similar between methods, targeted assessments estimated a large portion of the park to have the lowest density category (0–5 trail encounters per/km²), whereas the random transects in 2011 estimated more of the park as having the higher density categories (e.g., 15–20 encounters per km² category). Soil vulnerability categories that were assigned, a priori, based on published soil texture and composition did not accurately predict the impact of UTRs on soil, indicating that empirical methods may be better suited for identifying severity of compaction. While the estimates of UTR encounter frequencies were greater using the random transects than the targeted assessments for a relatively short period of time, it is difficult to determine whether this difference is dependent on greater cross-border activity, differences in technique, or from confounding environmental factors. Future surveys using standardized sampling techniques would increase accuracy.

Japanese knotweed (Fallopia japonica) is an herbaceous invader in North America and Europe with the ability to recruit via several modes (seeds, rhizome, and stem fragments). Within US riparian forests where Japanese knotweed invades, disturbances are common over space and time in the form of flooding and mowing. It remains unknown how disturbance influences the relative recruitment success of sexual and clonal propagules of this riparian invader. Using an experimental approach, we addressed this topic by planting seeds, and rhizome and stem fragments into riparian forest plots with intact Japanese knotweed subcanopies, and into plots with the Japanese knotweed subcanopy removed, simulating disturbance. We monitored canopy openness and propagule fate (shoot emergence and height) over five months. Regardless of treatment, rhizome fragments had a higher establishment probability (85%) than seeds (3%) or stem fragments (16%). Due to a small sample size, we did not analyze the effect of disturbance on seedling recruitment. Disturbance had little effect on the establishment of rhizomes and stems. Disturbance had a significant effect on the size and timing of shoot death from rhizome and stem fragments. During the fall we observed an earlier die-back of shoots from rhizomes in undisturbed treatment plots compared to disturbed treatment plots. Shoot height from rhizome and stem fragments was greater in undisturbed treatments than in disturbed. Our findings are limited to clonal propagules of Japanese knotweed but suggest that disturbance does not increase recruitment or propagule performance.

A Geographic Information System was used to analyze the protected fraction of river and lake ecosystem types in British Columbia (BC) to inform a more proportionally representative provincial protected areas system. Ecological Aquatic Units of BC (EAUBC) is a system of hierarchically classified rivers and lakes based on physiographic, climatic, and Zoogeographic characteristics. We analyzed the number and area of all 36 Ecological Drainage Units (EDUs), 23 river types (based on 18,100 classified rivers), and 12 lake types (based on 67,484 classified lakes) in BC, and considered each type under- or adequately represented relative to the total province-wide protected area (13.7%). Twenty-three of the 36 EDUs in BC are underrepresented. Coastal river ecosystems have a greater percentage of area protected relative to their total area compared to headwater, mainstem, and tributary systems. Underrepresented river ecosystem types include interior low-relief rivers, especially those in the northeast, and sheltered outer coast and island coastal rivers. Underrepresented lake ecosystem types include interior low-relief drainage lakes, interior low-relief isolated lakes in the northeast, and large, interior headwater lakes. Both river and lake high-relief systems have relatively high protection percentages because many of the province's larger protected areas are located in mountainous regions. Based on our river and lake representation analysis, we suggest focusing protection efforts on low-relief river and lake ecosystems, particularly interior and small isolated lakes. The methods described here provide a relatively simple GIS-based method for conservation managers to assess river and lake representation gaps.

Patterns of elevational distribution of alien plant species in the southern Sierra Nevada of California were used to test the hypothesis that alien plant species invading high elevations around the world are typically climate generalists capable of growing across a wide elevational range. The Sierra Nevada has been heavily impacted for more than a century and a half, first by heavy grazing up into high elevation meadows, followed by major logging, and finally, by impacts associated with recreational use. The comparative elevational patterns of distribution and growth form were compared for native and alien plant species in the four families (Asteraceae, Brassicaceae, Fabaceae, and Poaceae) that contribute the majority of naturalized aliens in the study area. The distribution of realized climatic niche breadth, as measured by elevational range of occurrence, was virtually identical for alien and native species, with both groups showing a roughly Gaussian distribution peaking with species whose range covers a span of 1500–1999 m. In contrast to alien species, which only rarely occurred at higher elevations, native species showed a distribution of upper elevation limits peaking at 3000–3499 m, an elevation that corresponds to the zone of upper montane and subalpine forests. Consistent with a hypothesis of abiotic limitations, only a few alien species have been ecologically successful invaders at subalpine and alpine elevations above 2500 m. The low diversity of aliens able to become established in these habitats is unlikely due to dispersal limitations, given the long history of heavy grazing pressure at high elevations across this region. Instead, this low diversity is hypothesized to be a function of life history traits and multiple abiotic stresses that include extremes of cold air and soil temperature, heavy snowfall, short growing seasons, and low resource availability. These findings have significant implications for resource managers.

Thalictrum cooleyi (Cooley's meadowrue, Ranunculaceae) is a federally endangered dioecious herb of wet pine savannas of the southeastern United States. We studied aspects of T. cooleyi biology crucial to conservation including its association with woody species, reproduction, and genetic structure in 11 populations in North Carolina and Georgia. Thalictrum cooleyi presence was negatively associated with canopy closure, but positively associated with shrub cover, including wax myrtle Morella cerifera. Deviations from strict dioecy are uncommon in T. cooleyi. Sex ratios differed significantly from 1:1, but despite male-bias in populations, pollen supplementation experiments found evidence for pollen limitation to seed set. Seeds are dormant at maturity. Cold stratification or gibberellic acid can break dormancy. Warm temperatures followed by cold stratification may increase germinability. Germination rates were low, likely due to low seed viability. Thalictrum cooleyi can be propagated vegetatively from caudex and rhizome divisions. AFLP analyses suggested that genetic diversity within and among populations is low. North Carolina and Georgia populations are genetically distinct, yet these limited data do not support hypotheses of separate species status or hybrid swarms. Our work suggests that habitat loss (i.e., transition of open pine savanna to dense forest), pollen limitation of seed set, poor seed viability, and possibly low genetic diversity within populations are major challenges to the recovery of T. cooleyi.

Amphibian species composition from arid and semiarid environments is different from that in tropical and temperate environments. Extensive areas of desert occur in the Chihuahuan Desert Region in protected areas, where the diversity of amphibians has not been analyzed. In this study, we analyzed anuran species richness of the protected area Real de Guadalcázar State Reserve. We also provide data on native species abundance during the dry and wet seasons. The area contained 37% of the amphibian species recorded from the entire Chihuahuan Desert Region. Various species of Anaxyrus occurred in different vegetation types, in addition to having high abundances during dry and wet seasons and low vulnerability scores. This study contributes to the knowledge of the diversity of anurans from arid and semiarid environments in the natural protected areas of northern Mexico. We also address possible conservation measures for these species.

We studied an upland forest located within the Grand Prairie region of Illinois and utilized tree-ring analysis to document tree cohort development and radial growth in relation to stand disturbance and climate. The overstory within the Humiston Woods Nature Center (Livingston County, Illinois) study area was dominated by oak (Quercus spp.), hickory (Carya spp.), and ash (Fraxinus spp.), while the subordinate crown classes were principally composed of elm (Ulmus spp.) and sugar maple (Acer saccharum). The study area contained tree cohorts originating during two recruitment periods. Overstory oaks and hickories primarily established between 1865 and 1900. A second tree cohort was associated with a timber harvest occurring in the late 1960s. In contrast to the 1865–1900 recruitment period, trees within the 1965–1980 cohort were primarily ash, elm, sugar maple, and black cherry (Prunus serotina). RWI values were most strongly correlated with Palmer Drought Severity Index, precipitation, and temperature in June of the current growth year. RWI and radial increment data for overstory oaks highlighted a sustained growth increase following a late 1960s timber harvest that remained high relative to predisturbance growth rates even in pronounced drought years. Data provide needed insight into oak woodland recruitment patterns relating to disturbance regimes that are difficult to recreate at the landscape level but often serve as ecological restoration objectives. Our findings help extend the foundational knowledge regarding forest composition, stand level dynamics, and radial growth relationships present among upland forests and changing disturbance patterns in the Grand Prairie region of Illinois.

Invasive nonnative species of woody plants can alter landscapes in ways that are detrimental to native wildlife. We studied branch structure of invasive nonnative Elaeagnus shrubs (autumn and Russian olive E. umbellata and E. angustifolia) as a potential influence on native bird activity in Midwestern habitats. In a comparison to three common native woody plants, Elaeagnus shrubs had a finer branch and denser structure than native black cherry (Prunus serotina) but did not differ from natives in other characteristics tested. Further, the morphological characteristics of Elaeagnus branches did not appear to affect preference for perching substrate at feeders or activity of birds moving through Elaeagnus and native shrub areas monitored using mist nets. Thus, we concluded that any morphological changes that may occur when Elaeagnus shrubs invade a habitat would not negatively impact overwintering and breeding bird perching behavior or movements during the nonfruiting season.

As a consequence of extensive habitat loss and fragmentation, grassland bird populations have declined substantially across much of North America. To assess management strategies for restoring and maintaining suitable habitat for grassland birds, we conducted a four-year survey of grassland-breeding passerines in the restored tallgrass prairies of the Carleton College Cowling Arboretum in Northfield, Minnesota. Between 2010 and 2013, we sampled bird populations weekly during the breeding season in ten adjacent management units that differed in size and spatial configuration. We used principal components analysis (PCA) to compare avian community composition among the units and to examine the association between habitat properties and makeup of the community. The size of a management unit had no effect on the bird community, but there was a strong impact of forest edge on community composition. Management units with less exposure to forest edge had greater abundance of grassland-obligate but not grassland-facultative birds. Management units that were less exposed to forest edge also had greater overall grassland bird diversity. These findings highlight the importance of maintaining grassland patches far from forest edges to increase habitat suitability for a diverse assemblage of grassland avifauna.

States in the Northern Rocky Mountains of the United States manage the gray wolf (Canis lupus) at low population levels through trophy hunting and lethal control. Although protected in Yellowstone National Park (YNP), wolves are subject to removal when they cross park boundaries. Thus, wolf management in the states adjacent to YNP is pitted against a large group of stakeholders interested in park wolves and their well-being. Federal and state decision makers should adopt “compassionate conservation” for Yellowstone wolves as a matter of equitable public policy and to improve biological and societal outcomes. Humane considerations should be paramount, given the high value and level of public interest in park wolves. This paper addresses the need to make animal welfare an essential aspect of wolf management in the YNP area.

The rich Western Balkans biodiversity and ecosystem services suffer from negative anthropogenic activities. Solving those problems requires a coherent strategy for biodiversity conservation with a focus on the involvement of relevant stakeholders. This paper presents a Local Biodiversity Action Plan (LBAP) as a tool for biodiversity protection and conservation on a local level in five countries of the Western Balkans. Results indicate that the LBAP improved local planning practices and secured stakeholder involvement by adequate stakeholder analysis and well defined incentives in the form of probiodiversity business (PBB). LBAP also enabled municipalities to assess biodiversity potential on their territory, and to develop a comprehensive planning document and biodiversity protection action plan.