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981.
Alternative forest management strategies to account for climate change-induced productivity and species suitability changes in Europe 总被引:1,自引:0,他引:1
982.
983.
Rebecca J. Howard Christopher J. Wells Thomas C. Michot Darren J. Johnson 《Environmental management》2014,54(1):30-50
Anthropogenic disturbances in wetland ecosystems can alter the composition and structure of plant assemblages and affect system functions. Extensive oil and gas extraction has occurred in wetland habitats along the northern Gulf of Mexico coast since the early 1900s. Activities involved with three-dimensional (3D) seismic exploration for these resources cause various disturbances to vegetation and soils. We documented the impact of a 3D seismic survey in coastal marshes in Louisiana, USA, along transects established before exploration began. Two semi-impounded marshes dominated by Spartina patens were in the area surveyed. Vegetation, soil, and water physicochemical data were collected before the survey, about 6 weeks following its completion, and every 3 months thereafter for 2 years. Soil cores for seed bank emergence experiments were also collected. Maximum vegetation height at impact sites was reduced in both marshes 6 weeks following the survey. In one marsh, total vegetation cover was also reduced, and dead vegetation cover increased, at impact sites 6 weeks after the survey. These effects, however, did not persist 3 months later. No effects on soil or water properties were identified. The total number of seeds that germinated during greenhouse studies increased at impact sites 5 months following the survey in both marshes. Although some seed bank effects persisted 1 year, these effects were not reflected in standing vegetation. The marshes studied were therefore resilient to the impacts resulting from 3D seismic exploration because vegetation responses were short term in that they could not be identified a few months following survey completion. 相似文献
984.
Bret A. Muter Meredith L. Gore Katie S. Gledhill Christopher Lamont Charlie Huveneers 《Conservation biology》2013,27(1):187-196
Investigation of the social framing of human–shark interactions may provide useful strategies for integrating social, biological, and ecological knowledge into national and international policy discussions about shark conservation. One way to investigate social opinion and forces related to sharks and their conservation is through the media's coverage of sharks. We conducted a content analysis of 300 shark‐related articles published in 20 major Australian and U.S. newspapers from 2000 to 2010. Shark attacks were the emphasis of over half the articles analyzed, and shark conservation was the primary topic of 11% of articles. Significantly more Australian articles than U.S. articles treated shark attacks (χ2 = 3.862; Australian 58% vs. U.S. 47%) and shark conservation issues (χ2 = 6.856; Australian 15% vs. U.S. 11%) as the primary article topic and used politicians as the primary risk messenger (i.e., primary person or authority sourced in the article) (χ2 = 7.493; Australian 8% vs. U.S. 1%). However, significantly more U.S. articles than Australian articles discussed sharks as entertainment (e.g., subjects in movies, books, and television; χ2 = 15.130; U.S. 6% vs. Australian 1%) and used scientists as the primary risk messenger (χ2 = 5.333; U.S. 25% vs. Australian 15%). Despite evidence that many shark species are at risk of extinction, we found that most media coverage emphasized the risks sharks pose to people. To the extent that media reflects social opinion, our results highlight problems for shark conservation. We suggest that conservation professionals purposefully and frequently engage with the media to highlight the rarity of shark attacks, discuss preventative measures water users can take to reduce their vulnerability to shark encounters, and discuss conservation issues related to local and threatened species of sharks. When integrated with biological and ecological data, social‐science data may help generate a more comprehensive perspective and inform conservation practice. Descripción de Tiburones y su Conservación por Medios Informativos Australianos y Norteamericanos 相似文献
985.
Christopher W. Simmons Hongyun Guo Joshua T. Claypool Megan N. Marshall Kristen M. Perano James J. Stapleton Jean S. VanderGheynst 《Waste management (New York, N.Y.)》2013,33(5):1090-1096
Soil solarization is a method of soil heating used to eradicate plant pathogens and weeds that involves passive solar heating of moist soil mulched (covered) with clear plastic tarp. Various types of organic matter may be incorporated into soil prior to solarization to increase biocidal activity of the treatment process. Microbial activity associated with the decomposition of soil organic matter may increase temperatures during solarization, potentially enhancing solarization efficacy. However, the level of organic matter decomposition (stability) necessary for increasing soil temperature is not well characterized, nor is it known if various amendments render the soil phytotoxic to crops following solarization. Laboratory studies and a field trial were performed to determine heat generation in soil amended with compost during solarization. Respiration was measured in amended soil samples prior to and following solarization as a function of soil depth. Additionally, phytotoxicity was estimated through measurement of germination and early growth of lettuce seedlings in greenhouse assays. Amendment of soil with 10% (g/g) compost containing 16.9 mg CO2/g dry weight organic carbon resulted in soil temperatures that were 2–4 °C higher than soil alone. Approximately 85% of total organic carbon within the amended soil was exhausted during 22 days of solarization. There was no significant difference in residual respiration with soil depth down to 17.4 cm. Although freshly amended soil proved highly inhibitory to lettuce seed germination and seedling growth, phytotoxicity was not detected in solarized amended soil after 22 days of field solarization. 相似文献
986.
This study examined resource conditions on backcountry campsites in Prince William Sound, Alaska, USA. In order to further the understanding of campsite impacts and to improve monitoring and assessment methods, we employed a multivariate analysis procedure, suggested in one study, but heretofore untested on data from other campsite assessments. Factor analysis of ten impact indicator variables from 146 campsites produced three dimensions of campsite impact—tree and vegetation disturbance, areal disturbance and visitor behavior-related disturbance. Three types of campsites, which differed substantially in the types of impact exhibited, were then derived from a cluster analysis of the factor scores. Further analysis revealed a significant relationship between the types of substrates where campsites were located and the types of campsites derived from the analysis. This work illustrates the utility of multi-indicator monitoring approaches and the use of multivariate methods for classifying campsites, as the campsite types identified would likely require different management strategies for limiting the proliferation and expansion of impacts. 相似文献
987.
Maria A. van Noordwijk Erik P. Willems Sri Suci Utami Atmoko Christopher W. Kuzawa Carel P. van Schaik 《Behavioral ecology and sociobiology》2013,67(5):805-814
In most mammals, females pay for reproduction by dramatically increasing net energy intake from conception to mid- or late lactation. To do this, they time their reproductive events in relation to environmental cycles so that periods of peak food availability coincide with peak demand or are used to build energy stores. This timing is not possible in species with slow development in which lactation is prolonged over a multi-year period with fluctuating food availability. Here, mothers are expected to sustain a stable but generally lower level of nutrient transfer. In a sample of over 1,050 complete follow days of eight mother–infant pairs collected over 7 years, we document maternal effort for wild Bornean orangutans (Pongo pygmaeus wurmbii) over their average 6.5-year lactation period. As predicted, maternal feeding time was independent of the age of her growing offspring, indicating a stable sustained “plateau” effort of ≤ 25 % above baseline level, instead of a short peak lactation as seen in seasonal breeders. Infant orangutans started to regularly supplement milk with self-harvested food when they were 1–1.5 years old, indicating milk intake was insufficient from this age onwards, even though maternal effort did not decrease. We expect the same regulation of sustained maternal effort in other large and large-brained mammals with slow infant development. We also predict that mother–infant conflict over suckling may show another peak at the onset of the milk?+?solid food phase, in addition to the well-known conflict around the endpoint of lactation (weaning), which is reached after a long and gradual increase in solid food intake by the infant. 相似文献
988.
Johan Höjesjö Bart Adriaenssens Torgny Bohlin Christopher Jönsson Illka Hellström Jörgen I. Johnsson 《Behavioral ecology and sociobiology》2011,65(9):1801-1810
The main aims of this study were to investigate (1) the occurrence and strength of the shyness–boldness behavioural syndrome
in brown trout fry, (2) whether this syndrome is associated with paternal migratory life history, (3) whether fry survival
and growth in the wild is associated with paternal life history and/or boldness and (4) whether offspring performance showed
maternal effects. Nine female migratory trout were each crossed with one migratory and one resident male and the offspring
were raised in hatchery tanks until first feeding. The behavioural studies showed that fry that responded bold towards a novel
object also accepted a novel food item earlier and responded more aggressively towards their own mirror image. Principal component
analysis showed that this shyness–boldness syndrome (PC1) explained 34% of the behavioural variation. Offspring boldness was
not affected by paternal migratory life history, but significant effects of the female parent suggested maternal and/or genetic
effects. Deviations from this pattern (PC2), where some individuals behaved less aggressively and performed more approaches
to food, explained an additional 17% of the variation in behaviour, and was significantly influenced by length and paternal
migratory life history. Fry growth and survival in nature was not associated with boldness (PC1) or PC2, suggesting that alternative
behavioural strategies can be successful in nature. However, female parent effects on variation in fry size persisted over
the first growth period in the wild, suggesting that these effects may influence offspring fitness during early life when
major selection occurs. 相似文献
989.
While US climate change mitigation policy has stalled at the national level, local and regional actors are increasingly taking progressive steps to reduce their greenhouse gas emissions. Universities are poised to play a key role in this grassroots effort by targeting their own emissions and by working with other local actors to develop climate change mitigation programmes. Researchers at the Pennsylvania State University have collaborated with university administrators and personnel to inventory campus emissions and develop mitigation strategies. In addition, they have facilitated a stakeholder-driven climate change mitigation project in one Pennsylvania county and started an ongoing service-learning project aimed at reducing emissions in another county. These campus and community outreach initiatives demonstrate that university-based mitigation action may simultaneously achieve tangible local benefits and develop solutions to broader challenges facing local climate change mitigation efforts. Outcomes include improved tools and protocols for measuring and reducing local emissions, lessons learned about service-learning approaches to climate change mitigation, and methods for creating climate change governance networks involving universities, local governments and community stakeholders. 相似文献