As conservationists develop strategies for managing coarse woody debris in natural areas information on the volume and distribution of deadwood in relatively undisturbed forests provides a valuable baseline for management goals. Hyrcanian mixed hardwood forests, within middle elevations of the Alborz Mountains bordering the Caspian Sea in northern Iran, experience few human disturbances and provide an ideal study site to examine woody debris in a mature forest. This study had three object tives: (1) measure volume of coarse and fine woody debris in Hyrcanian mixed hardwood forests; (2) compare density of forms of coarse woody debris (stumps, logs, and snags); and (3) correlate volume of living trees with volume of coarse woody debris. To sample the density and volume of dead wood, 15 plots of 1 ha (coarse woody debris) and 15 plots of 4 m2 (fine woody debris) were established. Coarse woody debris had an average volume of 15 m3 ha-1 and fine woody debris had an average of 10 m3 ha-1. The most common form of coarse woody debris was logs (67%) and the most frequent species was Oriental beech (Fagus orientalis) (55%). The volume of Oriental beech coarse woody debris was no significantly correlated with the volume of living Oriental beech trees (P = 0.77); however, the volume of European hornbeam (Carpinus betulus) coarse woody debris was significantly correlated to the volume of living European hornbeam (P = 0.01). The volume of coarse woody debris found in this study was considerably lower than has been measured in other Oriental beech forests and this may be a long-tern effect of historical grazing practices at this site, which emphasizes the importance of gathering a full historical context for a forest before it is used as a baseline for conservation management.

To investigate the hypothesis that Frangula alnus, glossy buckthorn, is causing a decrease in native plant diversity in forested plant communities of southwest New Hampshire, thirty nine 20-m × 20-m plots were established in five different forest types, and all buckthorn saplings and seedlings were removed from 15 of the plots. A nested plot design was used to sample shrubs and herbs. Treatment plots were kept free of buckthorn for five years. There was a positive relationship between pre-treatment buckthorn density and percent openness of the forest canopy, and with basal area of white pine (Pinus strobus), but not with soil wetness indicators. No significant changes in overall plant diversity or stem density were detected after buckthorn was removed, although stem density of woody plants, and seedlings of Acer rubrum did show significant increases in the treatment plots when compared to controls, but these effects were only seen in areas with the highest densities of buckthorn. No effects of buckthorn were observed below an average of 8.25 stems per m2. Compared to other areas of the northeastern United States, the densities of buckthorn were very low. Buckthorn seedling densities showed small increases in the control and monitoring plots, perhaps indicating a slow build-up to a “threshold” density, beyond which greater impacts on native species may be seen.

Astragalus microcymbus (Fabaceae) is a rare forb endemic to Gunnison County, Colorado. For 17 years, Denver Botanic Gardens and the U.S. Bureau of Land Management (Colorado State Office) have monitored four populations of this candidate species under the ESA in the South Beaver Creek Natural Area. Large, statistically significant population declines have been documented, as have prolonged dormancy, episodic fruit production, and herbivory. This study was initiated to learn about the life history of this rare species, determine the population trends, and examine management actions that will best support long-term survival of this species. Results indicate that while Astragalus microcymbus is declining in overall population size, it is following a large time scale cyclical pattern of growth and decline. Additional study is needed to fully understand the mechanisms driving mast seeding, prolonged dormancy, and population trends in this rare species.

Streptanthus bracteatus A. Gray, bracted twistflower (Brassicaceae), is a rare, endemic of the Edwards Plateau ecoregion of central Texas. We examined effects of light levels on the growth of S. bracteatus in a field experiment and also the combined effects of a canopy ( /-) and exclosure ( /-, herbivory) in a 2 × 2 factorial field experiment. Plants in the light experiment in high light had significantly greater growth compared to plants in the low light treatments. For most variables, plants in the factorial field experiment were negatively affected by herbivory (likely white-tailed deer, Odocoileus virginianus) and the presence of woodland canopy with significant interactions between herbivory ( /exclosure) and canopy treatments ( /-). Survival was 100% in exclosures and 58% when unprotected. Plants protected from herbivory and in the open had the greatest basal diameter, height, aboveground, belowground, and total dry mass, while those not protected from herbivory had much lower responses. Plants in the open, full sun, but not protected from herbivory, were lower in basal diameter, shoot height, aboveground, belowground, and total dry mass. Response variables were dependent on the presence or absence of an exclosure and canopy. Streptanthus bracteatus appears to be a sun-adapted plant, but is susceptible to herbivory by large ungulate herbivores. Both factors appear to determine, in part, the niche of this rare species.

We studied great gray owls (Strix nebulosa Forster) in Yosemite National Park, California, measuring variables that could potentially influence patterns of occurrence and conservation of this stateendangered species. We found that owl presence was closely tied to habitat (red fir (Abies magnified A. Murray) and the abundance of meadows), prey, and snags across the landscape. We also found that indicators of human recreational activities negatively influenced owl distribution and habitat use. Great gray owls appear to prefer mid-elevation red fir forest with meadows that are drier and more productive in terms of small mammal populations. That these areas also have the highest human activity presents a paradox, both for individual owls and for the future conservation and management of this California endangered species. The extent to which human recreation in natural areas affects animal behavior, species distribution, and productivity is a growing issue in natural area management. We present information that will allow land managers to better understand how existing natural resources, coupled with human recreation, influence the distribution and habitat use of the great gray owl.

The Colorado National Monument (COLM), on the northeastern edge of the Uncompahgre Plateau, supports a persistent Piñon (Pinus edulis Engelm.) — juniper (Juniperus osteosperma (Torr.) Little) woodland, which has not been disturbed by large stand-replacing fires since modern fire records began. We examined the fire history of large (> 100 ha) stand-replacing fires, documented tree population structures, and characterized tree density, quadratic mean diameter (QMD), relative composition, and cumulative mortality using 431 -0.1-haplots distributed over 1600 ha of the Monument. We found no evidence of large stand-replacing fires (charred wood or truncated stand structures) in the study area. Stand ages inferred from size structures suggest that large stand-replacing fires have been absent for possibly a millennia. Tree population structures show a more stable stand structure for juniper; Piñon pine population structures show a more recent and sustained regeneration pulse. Cumulative mortality of Piñon pines was 18%, peaking at 47% in trees 20 – 24.5 cm diameter. Spatial patterns of juniper density, QMD, and mortality were more homogeneous than those of Piñon pine. Results suggest temporal dynamics and spatial patterns of the COLM woodland are more influenced by drought and small fires (< 10 ha) than large fires (> 100 ha). This study provides important baseline data for changes that may be brought about by climate change in coming decades. It also stresses the importance of controlling cheatgrass (Bromus tectorum) and other invasive species to increase resistance of these persistent Piñon-juniper woodlands to future fires.

Non-native invasive plant species pose a serious threat to forest ecosystems around the world. Forest edges are associated with non-native invasive plants and forest interiors are often regarded as more resistant to invasion. The objective of this study was to determine if a large-scale wind disturbance facilitated the invasion of forest interiors by non-native invasive plant species. The northern portion of LaRue Pine Hills — Otter Pond Research Natural Area in the Shawnee National Forest of southern Illinois, was severely damaged by high winds during a powerful storm event on 8 May 2009. In the summer of 2011, 53 permanent research plots, as well as 20 additional plots located along roads that form the boundaries of the study site, were surveyed for the presence of 20 non-native invasive plant species. Only three of 53 interior plots (5.6%) contained invasive plant species (Lonicera japonica Lonicera maackii, and Rosa multiflora). Sixteen of 20 road plots contained a non-native invasive species (80%), and six species were identified (Dioscorea oppositifolia, Lactuca serriola, Lonicera maackii, Microstegium vimineum, Rosa multiflora, and Sorghum halepense). These findings indicate that wind damage does not appear to have facilitated invasion of forest interiors in the first two years following the storm. The spatial distribution of non-native invasive plants in the study area fits the pattern of other studies conducted in southern Illinois with non-native invasive plants associated primarily with forest edges and diminishing in the forest interior despite the apparent opportunity for establishment following the wind disturbance.

The Florida Scrub ecosystem depends on fire to sustain ecosystem function and to support resident plant and animal species. A recent study addressed the relationship between the time since last fire (TSF) and resident amphibians and reptiles in rosemary bald, one Florida Scrub habitat type. This is a parallel study in another Florida Scrub habitat type, scrubby flatwoods, at Archbold Biological Station (ABS), Lake Placid, Florida, USA. We installed 36 400-m² enclosures (four burn units within each of three TSF categories X 3 replicates per burn unit) at ABS. Bucket trap sampling, within and outside the enclosures, occurred during the spring and late summer in 2007 and 2008. Ten environmental variables that reflect differences in the biotic and abiotic conditions of the microhabitats associated with different TSF were surveyed. Eleven species of reptiles and six species of amphibians were captured. Three lizard species together accounted for > 95% of the reptile captures, and two toad species together accounted for > 96% of the amphibian captures. Abundance of the Florida Sand Skink (Plestiodon reynoldsi Stejneger) was highest in long-unburned areas, probably because of the accumulated litter; but abundances of the other two lizard species did not show a relationship with TSF. Differences in relative abundances of species between sampling years may be a function of the difference in rainfall. Despite substantial variation in sampling methods between this study and the previous one, the herpetofaunal composition of the two habitat types were found to be similar; differences in diversity between them was attributable mostly to differences in relative abundances. Species inhabiting the Florida Scrub ecosystem respond differently to TSF: the federally-listed Florida Scrub Jay (Aphelocoma coerulescens Bosc), for example, requires more frequent burning than appears to be the case for the Florida Sand Skink. A land management plan of stochastic return intervals and spatial variation of high-intensity fires to maintain a mosaic landscape would be ideal; but management options for maintaining the diversity of all species inhabiting the Florida scrub ecosystem are limited, because of the generally small size of remaining habitat patches.

Fire and grazing can interact to affect the structure and composition of vegetation communities in a manner that may differ from the effects of fire or grazing that occurs in isolation of the other. In order to better understand the effects of a fire-grazing interaction at the level of an individual plant species, we studied the response of a perennial tallgrass prairie forb, Arnoglossum plantagineum Raf., to the interaction of spring and summer fires with grazing by bison (Bison bison L.). During one field season (2006), we collected data in areas that had been treated with summer fires while in a subsequent field season (2007) we collected data in areas that had been treated with spring fires. Many measures of plant growth (plant height, vegetative biomass, and total biomass) and reproductive effort (reproductive biomass, indices of flowering plant density) suggested greater resource availability for individuals of A. plantagineum growing in areas that had been recently burned and were being heavily grazed by bison. However, the response of these variables to the fire-grazing interaction often varied among differing topographical positions. Our results demonstrate that the interaction of fire and bison grazing can further interact with topographical position in tallgrass prairie to affect the growth and reproductive effort of the perennial forb A. plantagineum.

Mangrove communities usually occur in the intertidal zone within tropical and subtropical coastal zones in sheltered saline to brackish environments. It is difficult to monitor and manage mangroves due to a lack of baseline data on the mangrove stmctural properties in the Persian Gulf and Oman Sea. This study investigated the structure of mangrove forests in the Hormozgan province, south of Iran. This study was performed in the Hara Protected Area (HPA) and Gaz and Hara Rivers Delta (GHRD), using random 5-m x 5-m quadrates. A total of 101 Avicennia marina trees in HPA and 172 Rhizophora mucronata trees in GHRD were measured. The average density, tree height, diameter at breast height, crown spread, canopy index, above ground biomass, and litterfall were 1005 ± 68.11 stem ha-1, 2.51 ± 0.17 m, 17.44 ± 0.8 cm, 1.97 ± 0.16 m, 56.06 ± 2.85 (%), 72 ± 9.8 t ha-1 and 9.4 ± 8.5 t ha-1 yr-1 for the A. marina stands, respectively, while 1110.77 ± 182.58 stem ha-1, 2.78 ± 0.46 m, 11.73 ± 1.50 cm, 1.39 ± 0.06 m, 78.54 ± 2.4 (%), 66 ± 11 t ha-1, 5.1 ± 6.9 t ha-1 yr-1 were recorded for R. mucronata stands, respectively. The density, tree height, and canopy of R. mucronata were higher than A. marina (p < 0.05). The diameter at breast height, crown spread, above ground biomass, and litterfall were higher at A. marina habitat. All parameters except tree height were significantly different between HPA and GHRD habitats. Due to the different structure of A. marina and R. mucronata along the Hormozgan coast of Persian Gulf and Oman Sea, the best management strategies to conserve these productive habitats are required.

Much of conservation biology has focused on developing approaches for selecting high value sites for protecting biodiversity; what has been lacking are objective criteria for delineating conservation boundaries. Defining protected area boundaries based on occupied species' habitat offers no guarantee that those reserves will continue to provide suitable habitat over time. Focusing on ecosystem protection rather than just species' populations offers a mechanism to protect those species, and does so in a dynamic context. It is the multiple temporal and spatial scales of ecosystem processes that drive habitat dynamics, foster biodiversity, and facilitate adaptations to changing conditions. Embracing the dynamics of ecosystems and their boundaries as criteria for reserve designs also forces a conceptual shift in how to assess populations within conservation areas. Monitoring programs must focus on understanding drivers of change rather than how much change has occurred relative to an arbitrary baseline. The conceptual shift to an ecosystem focus broadens the levels of biodiversity encompassed in a conservation design, and gives greater resilience to the stressors of fragmentation, invasive species, and climate change. California's Coachella Valley Multiple Species Habitat Conservation Plan is highlighted as a conservation design that has adopted an ecosystem focus.

Nature protection in The Republic of Serbia dates back to the Middle Ages. The current nature protection in Serbia has been regulated by the relevant legilsative and institutional framework harmonized with the European Union environmetal accord. However, the total protected areas are still small in comparison to the existing natural values that deserve to be protected and maintained.