Natural Areas

Grassland restoration attempts to rehabilitate and/or re-create biologically diverse native plant communities using a variety of management techniques including seeding, burning, grazing, and most recently using herbicides. Herbicides are an important tool for suppressing weed competition for initial seedling growth and removing exotic species in native plant communities. Little information is available on which species of native plants can endure a pre-emergent application of the imidazolinone herbicides. In spring 2006, we initiated a study testing responses of three native grasses and three native forbs to pre-emergent treatments of 0.035 kg ai/ha imazapic, 0.07 kg ai/ha imazapic, and 0.07 kg ai/ha imazapyr. Seedling establishment was monitored at 5 and 14 months after treatment and weed cover was monitored at 2.5, 5 and 14 months after treatment. There were no differences in the number of seedlings found in the untreated plots compared to all the herbicide-treated plots and there were no differences in seedling densities of green needlegrass (Nassella viridula) with the exception of the high imazapic treatment. Showy tick trefoil (Desmodium canadense) and Canada milk vetch (Astragalus crassicarpus) also appear to be able to tolerate applications of all herbicide treatments. There was less weed cover in the herbicide-treated plots when compared to the untreated control plots. This information provides managers options to include these species in initial seeding or restoration projects using these herbicides which may increase diversity and reduce restoration projects cost in the long term.

All species of the genus Turbinicarpus are considered to be at risk and are thus included in CITES Appendix I. Ex situ plant reproduction has been suggested to reduce illegal extraction of these species. However, literature regarding seed germination of these species is scarce and often contradictory. Propagation requirements among 17 taxa (including 12 species, six subspecies, and one hybrid) were analyzed. We used fresh seeds for all taxa plus aged seeds for five species. The response variable measured was Germinative Value (GV), which measures germination quality resulting from three variables: germinability, germination speed, and germination uniformity. For fresh seeds, significant differences were found between taxa. Germination varied broadly across taxa from 8% to 97% and GV ranged from 0.848 to 20.112. The two taxa with lower GV, T. lophophoroides and T. pseudopectinatus, showed higher GV in old seeds than in fresh seeds, which indicates this species might form seed-banks in the soil. T. knuthianus did not show significant differences between fresh and old seeds, which can be interpreted as a strategy to produce both seeds for immediate propagation and seeds for securing the medium and long-term survival of the species. In contrast, T. swobodae and T. valdezianus showed higher GV in fresh seeds than in old seeds, which would appear to represent an adaptation to germinate as soon as rainfall occurs. Our results contribute to understanding germination biology of a threatened genus and the potential role of soil seed banks. In addition, results presented here could contribute to in situ conservation of Turbinicarpus spp. populations, through promoting natural regeneration, and ex situ conservation, by promoting large numbers of cultivated individuals outside their habitats.

We analyzed germination percentages and germination rates at four temperature treatments (5/15, 10/20, 15/25 and 20/35 ºC) and in light or darkness in four endemic species of the genus Gymnocalycium with different flowering phenologies from the Córdoba Mountains (Argentina). Gymnocalycium bruchii flowered and dispersed its seeds very early in the season in comparison to the other three species. No seeds germinated in darkness or at the coldest temperature regime. For all species except G. bruchii, germination was higher at the two warmest treatments. Gymnocalycium bruchii germination was maximum at the second warmest temperature (15/25 ºC) and did not germinate at all at the highest temperature treatment (20/35 ºC). Germination varied strongly among species, from about 80% in G. quehliaum to 20% in G. monvillei. Germination rate (t 50 ) varied more strongly among temperature treatments (from 15 to 7 days in the coldest and warmest treatments respectively) than among species. The lack of germination of G. bruchii at 20-35 °C could be related to its early flowering phenology.

The state of Baja California Sur has the largest protected surface area in Mexico, amounting to approximately 2,813,914 ha (38.3% of the state area). Included are two biosphere reserves, a submanne refuge of flora and fauna, and severa1 islands in the Gulf of California. These reserves and refuges provide legal protection for most of the ecosystems of the region. The state's protected areas are distinguished by the occurrence of a great number of marine mammals, severa1 nesting and wintering sites for migratory and resident aquatic birds, severa1 endemic and threatened species, and numerous archaeological sites. This paper describes the status of these reserves and refuges in terms of category of protection, legal status, biodiversity, and species statuses. In addition, we appraise the management of these protected areas and the importance of management to the conse~ation of the natural resources of the state, region, and country.

Restoration and conservation may be enhanced by using ecologically-based methods for prioritizing actions. Efforts are currently underway to restore river flows to the San Joaquin River in California's Central Valley. Although fish are the primary restoration target for restored flows, complementary efforts are being designed to protect, enhance, and restore riparian and floodplain habitats to benefit the larger ecological community. We describe our efforts to use bird habitat distribution models to inform and prioritize conservation activities along the San Joaquin River. We demonstrate the integration of habitat distribution models into an established conservation planning process that illustrates the synergies and tradeoffs of protecting high quality habitat for multiple species-groups and other restoration opportunities on the San Joaquin River. We used quantitative models to develop habitat quality indices for marsh birds, early-successional riparian birds, and mid/late-successional riparian birds, and used these indices to rank 18 sites under consideration along the San Joaquin River. We found little evidence that the rankings of the 18 sites for the three habitats were correlated, suggesting that any prioritization decisions will need to consider the quality of all three habitats, rather than one habitat acting as a surrogate for the others. Considering the habitat model rankings together with expert opinion rankings based on existing habitat quality, restoration potential, and flood management opportunities allowed us to identify sites that ranked high across multiple criteria. These results illustrate a simple process by which quantitative information from habitat models can be combined with expert opinion to inform priorities for protection and restoration.

We surveyed high quality, remnant black oak sand savannas across four sites in northeastern Illinois to compare characteristics of stand structure and tree vigor with fire history. Dendrochronological methods were applied to 289 dated fire scars identified on 60 Quercus velutina trees. Stand structure was characterized using 30 circular plots (0.04 ha each) per stand during summer 2007. Tree recruitment dynamics differed among the four stands, suggesting that canopy decline dynamics among them is likely to differ in coming decades. Frequent fire intervals (less than two years) were associated with canopy openness, but also a paucity of future canopy trees. Under these frequent fire regimes, we predict a loss of canopy cover, as no smaller trees were present to assume dominance. Fire intervals longer than two years were associated with transition to closed canopy forests. These results suggest that savanna managers should consider other disturbances, such as selective cutting and or grazing, along with fire to sustain both herbaceous and canopy tree components.

The black-footed ferret (Mustela nigripes), once extinct in the wild, remains one of the most critically endangered mammals in North America despite 18 years of reintroduction attempts. Because black-footed ferrets are specialized predators of prairie dogs (Cynomys sp.), a better understanding of how black-footed ferrets select resources might provide insight into how best to identify and manage reintroduction sites. We monitored ferret resource selection at two reintroduction sites with different densities of prairie dog populations-one that contained a high density of prairie dogs (Conata Basin, South Dakota) and one that was lower (UL Bend, Montana). We evaluated support for hypotheses about ferret resource selection as related to the distribution of active burrows used by black-tailed prairie dogs (Cynomys ludovicianus), interactions between ferrets, and habitat edge effects. We found support for all three factors within both populations; however, they affected ferret resource selection differently at each site. Ferrets at Conata Basin tended to select areas with high prairie dog burrow density, closer to the colony edge, and that overlapped other ferret ranges. In contrast, ferrets at UL Bend tended not to select areas of high active prairie dog burrow density, avoided areas close to edge habitat, and females avoided areas occupied by other ferrets. The differences observed between the two sites might be best explained by prairie dog densities, which were higher at Conata Basin (119.3 active burrows per ha) than at UL Bend (44.4 active burrows per ha). Given the positive growth of ferret populations at Conata Basin, management that increases the density of prairie dogs might enhance ferret success within natural areas. To achieve long-term recovery of ferrets in the wild, conservationists should increasingly work across and outside natural area boundaries to increase prairie dog populations.

Lightning-and human-ignited fires have shaped many of Florida's natural communities. Plant persistence in these habitats requires adaptation to survive high temperatures, ability to respond to aboveground tissue loss, or avoidance of these conditions through survival in unburned patches or in the soil seed bank. Limited distribution of many rare species in increasingly fragmented habitats and uncertainty of whether rare species tolerate, require, or persist through avoidance of fire hampers fire management when it is possible and threatens long-term viability of plants. We review up to 14 years of monitoring data for 18 rare plant species from 14 families occurring on sandhill, scrub, pine rockland, and mixed deciduous hardwood communities across Florida. For a number of variables measured, including density, frequency, flowering, and recruitment, 50% of the species showed significant positive responses to burning and 50% of the species showed a neutral or no response. None of the species were unable to recover post-burn. These results suggest that prescribed fire in these pyrogenic habitats need not be delayed until species-specific responses to fire are understood.

We compared the native bees visiting the flowers of three species of invasive plants, saltcedar (Tamarix spp.) and white and yellow sweet clover (Melilotus albus, M. officinalis), with those visiting seven concurrently blooming native plant species in mid-summer at three sites in Capitol Reef National Park, Utah. Overall, as many total species of bees visited the flowers of the three invasive plant species as visited the seven natives. On average, invasive species were visited by twice as many bee species as were natives. With a single exception, visitors of invasives were generalist bees, rather than specialists. Colletes petalostemonis, the only native legume specialist recorded, was an abundant forager on the flowers of both species of Melilotus, demonstrating that at least some specialist bees will move to invasive plants that are closely related to their usual hosts. Species abundant on the flowers of invasives tended to collect both pollen and nectar, suggesting that bees are using pollen of Tamarix and Melilotus to provision their offspring. We argue that invasives with entomophilous flowers are unlikely to either facilitate the reproduction of uncommon native plants or consistently compete with them for pollinators. Rather, they are likely, over time, to selectively increase the carrying capacity and population size of native bees, specifically generalists, and specialists of closely related plant species.

The use of indicators for the determination of the sustainability is a relatively newly tool and for that reason it is loaded of improvement opportunities. The introduction of the concept of sustainable Development and later its polidimensional definition made by the Commission of Sustainable Development of the United Nations, allows that it is possible to be advanced in the construction of indicators with this approach. In this work were analysis 19 systems of indicators on international and national scale, as well as of specific level for natural tourism and areas; for it, a methodology based on the radial representation of the these systems of indicators was used, arranging as a axes each one of the dimensions of the sustainable development. This analysis allowed to observe that most of the works until now made they maintain a noticeable approach environmental (physical-natural), that limits so much the use of these systems of indicators, like the information that they provide.

Despite the proximity of Sonora, Mexico, to the United States, the mammalian fauna of Sonora has been poorly investigated, and many of the biological and ecological characteristics of these animals remain unknown. From July 1999 to August 2001, we carried out a mammalian inventory using camera traps surveys in order to provide information on the occurrence, distribution, habitat association, and activity patterns of medium and large-sized terrestrial mammals in the three major habitat types of the Sierra Madre Occidental foothills in east-central Sonora: (1) Sinaloan thornscrub (ST), (2) Oak woodland (OW), and (3) thornscrub-woodland ecotones (TW). Over 2348 trap-nights, we obtained 897 photographic records, documenting 18 species of wild mammals. White-tailed deer (Odocoileus virginianus), gray fox (Urocyon cinereoargenteus), mountain lion (Puma concolor), and coyote (Canis latrans) were the most frequently recorded and widely distributed species. In addition, we documented the presence of two endangered species, the jaguar (Panthera onca) and ocelot (Leopardus pardalis), as well as a threatened species, the badger (Taxidea taxus).

The identification and inventory of remnant-dependent or conservative species is an essential prerequisite to sound reserve selection and management in severely fragmented regions. We expanded an ongoing study of insect conservatism to include approximately 1200 additional species on 50 prairie and savanna remnants in the Chicago Wilderness Region (CW). Approximately 700 surveys were conducted from 1995 to 2006, with special emphasis placed on 15 high quality reserves. Our objectives were to:

Culturally modified trees (CMTs) are trees with scars that reflect human utilization of forested ecosystems. Some CMTs can reveal unique knowledge of native cultures and insight to peoples' subsistence and land use in the past, and are mostly to be found in protected areas since they contain very old trees. In this study, we examine attributes and the spatial and temporal distribution of barkpeeled trees, and present forest structure in two remnant ponderosa pine forests (Pinus ponderosa P. & C. Lawson) in western Montana. We also wanted to use an alternative method of dating CMTs and initiate a broader discussion of threats to such trees and needs for sustaining and protecting them. In total, 343 bark-peelings were recorded on 274 living and dead trees. Our results show that only certain trees were selected for harvest. Nearby trees of similar size and age were not used. The age estimation indicates that the bark-peelings were performed from the mid 1600s until the early 1900s. Today the forest at both study areas is generally low in density and all-aged with very old individual trees. They consist of a mosaic of uneven-aged tree groups and individual trees of various ages. We conclude that the abundance and density of bark-peeled trees at the study areas exceed values reported in most other North American studies (formally protected forests included), that the two areas represent different harvest areas for ponderosa pine inner bark, and that CMTs need to be recognized both as ecologically and culturally valuable features of old ponderosa pine forests.

Seed dormancy and seed longevity partially determine the crucial stages of germination and establishment of seedlings for rare Cactaceae in arid environments. We studied the effect of seed age and seed dormancy on germination and seedling establishment of an endangered species of cactus (Mammillaria huitzilopochtli) from Oaxaca, Mexico, in controlled and natural conditions. Germination experiments were conducted in greenhouse conditions and seedling survival was assessed in controlled and natural areas. We found that M. huitzilopochtli has non-dormant seeds and that germination occurred during the first seven days after sowing for seeds less than one year old (x = 90%). Germination decreased with time, which indicated that this species might be able to form a transient seed bank (maximum one year old). Scarification treatments in M. huitzilopochtli did not interact with seed age response and did not enhance germination percentages, asserting that seeds are nondormant. When compared with other species of the same genus inhabiting the same region, we conclude that dormancy in cacti is probably more related to environmental heterogeneity than to phylogenetic constraints. Similar to the majority of cacti species, seedlings of M. huitzilopochtli only established in shade conditions. The seeds and seedling traits of this endangered species must be taken into account for conservation programs. Because few seeds were produced yearly, no seeds could be stored at room conditions for long time periods (> 2 yr) and seedling survival was low (mean = 13.75%).

Grazing by large herbivores has the potential to facilitate invasion of natural grasslands by non-native plant species. Often, both herbivore identity and plant community type modulate this effect. The objective of this study was to evaluate the impact of grazing on non-native plant species richness and cover in montane grasslands of central Argentina as related to herbivore identity (horse or cattle) and plant community type. The study was conducted in piedmont valleys of the Ventania Mountains. The area is occupied by two major types of plant communities: short-needlegrass and tall-tussock grasslands. Short-needlegrass grasslands occupy poor soils and have higher plant species diversity compared to tall-tussock grasslands which typically grow on rich soils. Part of the study area is devoted to cattle husbandry, part is inhabited by feral horses, and part has been free of grazing by large herbivores for the last 15 years. We compared non-native species richness and cover at three levels of grazing (horse grazing, cattle grazing, grazing exclusion) and two levels of plant community type (short-needlegrass grassland and tall-tussock grassland) at the end of the growing season in 2006 and 2007. Thirty-one nonnative plant species were found growing in the study area. Grazing increased non-native species richness and cover and was highest under horse grazing and in communities on resource-rich soils. Our results are consistent with the hypothesis that grazing by large non-native herbivores can facilitate non-native plant species invasion of natural grasslands. They also suggest that herbivore identity and community type modulate the effect of large herbivore grazing on grassland invasion by non-native plant species.

Natural reserves or protected areas are a keystone of global strategies for biological conservation. With over 18% of its land under protection, Chile faces challenges similar to those in other developing countries. In this paper we describe the history and status of protected areas in Chile, and identify the challenges that the country confronts for improving the conservation and social efficacy of protected areas. Following the modern "pristine" concept of protected areas, Chile created its first protected area in 1907 and the first national park in 1925. Historically, several national and local agencies were in charge of the creation and management of protected areas. In 1984, the national public system of protected areas was created to organize the scattered protected areas around a unified system that seeks to conserve Chilean natural resources. The system has several problems that jeopardize its capability to conserve Chilean biodiversity: insufficient ecosystem representation, inadequate coverage of biodiversity hot-spots, low budgets, and boundary issues. Private protected areas have recently been considered as complementary units to SNASPE. But there are questions about long-term commitment and restriction to development in such areas. The growth of ecotourism may be boosting SNASPE and private reserve initiatives, but it may also threaten the conservation of pristine environments. We propose that protected areas in Chile be part of a comprehensive conservation policy that considers the entire range of natural resources. This policy should also address new ways to conserve biodiversity outside protected area boundaries, bringing both private and public initiatives together.

Deer have been overabundant throughout much of Pennsylvania since at least the 1940's. We compared plant communities in the Allegheny National Forest (ANF) on boulder tops and the forest floor to test the hypothesis that large boulders serve as refugia for plants threatened by deer herbivory. Five of the ten most common woody species (hemlock, Tsuga canadensis L., mountain maple, Acer spicatum Lam., red maple, A. rubrum L., striped maple, A. pensylvanicum L., and yellow birch, Betula alleghaniensis Britton) occurred at much higher densities on boulders than in randomly selected areas of the same size adjacent to these boulders on the soil surface. We never encountered any individuals of hemlock, mountain maple, or red maple on the forest floor. Total woody species density (excluding root suckers of beech, Fagus grandifolia Ehrh.) was nearly three times higher on the boulders. Woody species richness and evenness, as well as forb and shrub cover and richness, were also much greater on boulders. Our results strongly suggest that overbrowsing by deer can dramatically reduce tree regeneration and diversity as well as reduce forb and shrub abundance in the ANF. Furthermore, understory plant communities are now dominated by species that are known to be unpalatable or tolerant of deer browse, particularly beech, grasses, and ferns (Dryopteris carthusiana Vill. and Thelypteris noveboracensis L.). The primary alternative explanation is that conditions on the surface of boulders are superior for numerous woody and herbaceous species. Although we cannot rule this out, we consider this alternative improbable because of the poor nature of these habitats.

ABSTRACT: Fire regimes of pine savannas on barrier islands along the coast oí lhe Gulf of Mexico are unknown. We used dendrochronological techniques lo precisely date scars from 52 slash pines {Pinus eilioftii Engelm.) located within a 370 ha area on Linie St George Island. Florida, USA, an undeveloped barrier island. We determined the ytans and seasons of fires and turpentine operations, and mapped the Spatial distribution of past fires. We identified five separate periods with different fire frequencies. Fires were frequent between ...

Natural reserves or protected areas are a keystone of global strategies for biological conservation. With over 18% of its land under protection, Chile faces challenges similar to those in other developing countries. In this paper we describe the history and status of protected areas in Chile, and identify the challenges that the country confronts for improving the conservation and social efficacy of protected areas. Following the modern "pristine" concept of protected areas, Chile created its first protected area in 1907 and the first national park in 1925. Historically, several national and local agencies were in charge of the creation and management of protected areas. In 1984, the national public system of protected areas was created to organize the scattered protected areas around a unified system that seeks to conserve Chilean natural resources. The system has several problems that jeopardize its capability to conserve Chilean biodiversity: insufficient ecosystem representation, inadequate coverage of biodiversity hot-spots, low budgets, and boundary issues. Private protected areas have recently been considered as complementary units to SNASPE. But there are questions about long-term commitment and restriction to development in such areas. The growth of ecotourism may be boosting SNASPE and private reserve initiatives, but it may also threaten the conservation of pristine environments. We propose that protected areas in Chile be part of a comprehensive conservation policy that considers the entire range of natural resources. This policy should also address new ways to conserve biodiversity outside protected area boundaries, bringing both private and public initiatives together.

Sphagnum bogs in the southern Appalachian Mountains of eastern North America are rare and diverse ecosystems; the unique climate range they occupy allows for a mixture of northern and southern species to thrive, creating isolated biodiversity hotspots. Research on northern bogs in Europe and North America has found that climate change and atmospheric nitrogen deposition can shift species composition of bog communities and release carbon; however, research on southern bogs has not begun to answer questions about their fate. We reviewed research conducted in northern bogs and applied this information to southern Appalachian bogs to explore the potential impacts that climate change may have on southern Sphagnum bogs. The projected increase in evapotranspiration coupled with nitrogen deposition may lead to the drying up of southern bogs causing: (1) increased decomposition rates, which can lead to the system becoming a carbon source rather than a sink; and (2) local extinction of many bog species, allowing alternative ecosystems to replace the bogs. Because of these threats, we suggest a call to action for scientists and managers to begin investigating the specific impacts that climate change will have on bogs in the southeastern United States so we may better protect and conserve these unique and diverse habitats.

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.

Coastal succulent scrub of Baja California is being fragmented and replaced by agriculture, residential, recreational, commercial, and industrial land uses. This study evaluated fragmentation effects of a residential-recreational development. The site was a mosaic of native coastal succulent scrub (CSS) in a matrix of introduced grasslands and tourism infrastructure. Comparisons were made among extensive areas of mature or old CSS and smaller patches, which were either recently fragmented in a golf course or fragmented more than 20 years ago in a residential area. Total plant species richness was 108 species. New fragments exhibited the highest floristic richness due to invasion by opportunistic species. The number of CSS species increased with patch size. There were differences in flora among seasons due to spring annuals. In contrast, cover by native perennials was similar among all conditions and MANOVA results showed that only the variables related to origin (natives and nonnatives) were significant. This means that neither life form nor fragment type was related to the species number. Our study reflects the potential to preserve coastal sage scrub patches within an urbanized area.

The role of ungulates as contributors to establishment and spread of non-native invasive plants in natural areas is not well known. The objectives of this study were to document whether or not sulfur cinquefoil (Potentilla recta L.) is grazed by ungulates and to quantify the effects of ungulate herbivory on the density and demography of sulfur cinquefoil. Despite reports suggesting sulfur cinquefoil is minimally grazed, our results indicate that substantial grazing of sulfur cinquefoil occurs in a northeastern Oregon natural area. The number of sulfur cinquefoil flowers and seed heads differed significantly (P < 0.0001) among all grazing treatments at all sampling periods. Cattle (Bos Taurus) grazed sulfur cinquefoil throughout early summer, resulting in smaller plants with few flowers and subsequent seed heads. Sulfur cinquefoil was grazed by deer (Odocoileus heminous and O. virginianus) and elk (Cervus elaphus) primarily in the fall and winter by specifically removing just the seed heads. As sulfur cinquefoil reproduces only by seed and seeds typically fall within 3 m of a parent plant, grazing by ungulates and subsequent deposition of the seeds by endozoochory may explain the establishment of satellite infestations across susceptible natural areas.

The pace of habitat destruction and loss of biological diversity globally exceeds the current capacity of societies to restore functioning ecosystems. Working with prison systems to engage inmates in habitat conservation and ecological science is an innovative approach to increase our ability to reestablish habitat and at-risk species, while simultaneously providing people in custody with opportunities for reciprocal restoration, education, therapeutic activities, safer conditions, and lower costs of imprisonment. We present the benefits of working with prisons to conduct habitat conservation through nursery production of plants and captive rearing of animals, combined with educational experiences, and provide an overview of the Sustainability in Prisons Project Network. Examples of projects with prisons in Washington and Oregon include nursery production of Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis) for restoring habitat of the greater sage-grouse (Centrocercus urophasianus), nursery production of early blue violet (Viola adunca) to support conservation of threatened Oregon silverspot butterflies (Speyeria zerene hippolyta), captive rearing programs for Oregon spotted frogs (Rana pretiosa) and endangered Taylor's checkerspot butterflies (Euphydryas editha taylori), and nursery production of over 60 plant species for restoration of native prairies. Including incarcerated people in conservation and science could tap into the positive potential of over 2 million inmates at over 4000 prisons and jails in the United States and create new partnerships to support large-scale habitat restoration and ecological research.

We report the status of alien species on Isla de Cedros, Mexico, and analyze the information from different years that together with a collaborative effort between academic biologists, Mexican governmental agencies, and local individuals has resulted in major information about the alien species on this island. We also report species richness of distinct endemic mammal species and the presence of feral dogs (Canis lupus familiaris Linnaeus), which is the principal problematic situation in this "Marine Priority Region." The possible origin of feral dogs could be the migratory movement of stray dogs to find food in the inner part of the island, first moving to garbage dumps, reproducing in the area, and later hunting goats (Capra aegagrus hircus Linnaeus) in packs. The combination of the high density of stray dogs, urban and industrial food garbage dumps, and the large number of marine resources scattered along the seashore made ideal conditions for the establishment of feral dog packs that are affecting native species. The island does not have any natural mammal predator, but the presence of feral species, dogs and cats (Felis silvestris catus Schreber), could disturb the occurrence of endemic fauna as it has happened on other islands in the world.

Seed dormancy and seed longevity partially determine the crucial stages of germination and establishment of seedlings for rare Cactaceae in arid environments. We studied the effect of seed age and seed dormancy on germination and seedling establishment of an endangered species of cactus (Mammillaria huitzilopochtli) from Oaxaca, Mexico, in controlled and natural conditions. Germination experiments were conducted in greenhouse conditions and seedling survival was assessed in controlled and natural areas. We found that M. huitzilopochtli has non-dormant seeds and that germination occurred during the first seven days after sowing for seeds less than one year old (ξ = 90%). Germination decreased with time, which indicated that this species might be able to form a transient seed bank (maximum one year old). Scarification treatments in M. huitzilopochtli did not interact with seed age response and did not enhance germination percentages, asserting that seeds are nondormant. When compared with other species of the same genus inhabiting the same region, we conclude that dormancy in cacti is probably more related to environmental heterogeneity than to phylogenetic constraints. Similar to the majority of cacti species, seedlings of M. huitzilopochtli only established in shade conditions. The seeds and seedling traits of this endangered species must be taken into account for conservation programs. Because few seeds were produced yearly, no seeds could be stored at room conditions for long time periods (> 2 yr) and seedling survival was low (mean = 13.75%).

The Palouse Prairie of eastern Washington State and adjacent northern Idaho is an endangered ecosystem. Like other arable North American grasslands, the prairie was mostly converted to agriculture in the late 1800s, and native habitat is today highly fragmented within a matrix of production agriculture. Government and conservation groups are beginning conservation action in the region, but lack information regarding the number and nature of the prairie remnants. We used high-resolution aerial photography to identify potential prairie remnants in the southern half of the Palouse and describe their physical characteristics. We found that although there are many potential remnants, they tend to be small (most less than 2 ha) and have high perimeter-area ratios. Potential remnants are disproportionately found on rocky and shallow soils in the region, with only a few located on the deepest, most agriculturally valuable soil types. The remnants occur predominantly in a few large clusters near rivers and rocky buttes, and over half are within 150 m of the next nearest remnant. Almost all remnants are privately owned. The high number and clustered distribution of the remnants suggest a conservation strategy for the Palouse may be based on developing a network of small reserves. This may be best implemented at the county level through outreach efforts and partnerships with private landowners.

The loss of native biodiversity is a major ecological issue in human-dominated landscapes. In particular, the tree regeneration failure of deciduous forests remnants in suburban landscapes is of great concern to land managers and forestry associations. We tested the responses over two growing seasons of herbaceous plants and tree seedling survival and growth to the removal of invasive plant competition and deer herbivory. We first tested the response of understory vegetation to the removal of Microstegium vimineum (Japanese stiltgrass), a non-native invasive grass, and the removal of deer herbivory, via exclosures, in two forest fragments in central New Jersey. We then explored the restoration potential of planted seedlings of canopy tree dominants, Acer rubrum, Fraxinus americana, and Quercus rubra. The herbaceous community responded with an increase in species richness to the removal of M. vimineum. There was no response of the herbaceous community to the removal of deer herbivory, indicating that the herbaceous community will not recover rapidly from removal of these stressors alone. Survival and height growth of naturally regenerating tree seedlings increased with the removal of M. vimineum and the removal of deer herbivory, but these effects were not interactive. The survival and growth of planted seedlings of two tree species, F. americana and Q. rubra, were depressed by the presence of M. vimineum. Our results suggest that intensive management of M. vimineum and deer populations as well as active re-vegetation of herbaceous communities and tree seedlings are necessary to restore plant biodiversity in suburban deciduous forests.