Effects of Recreational Impacts on Soil Microbial Communities

/ The functional diversity of soil microbial communities in heavilyimpacted subalpine campsites and adjacent undisturbed areas was comparedusing the Biolog method of carbon utilization profiles. Principal componentsanalysis of patterns and level of microbial activity indicate that microbialcommunities differentiate in response to disturbance in the top 6 cm of soil,while below 6 cm there were no recognizable differences between disturbed andundisturbed soil communities. Analysis of the factors that differentiate theupper microbial communities between disturbed and undisturbed sites revealedthat the percent of total carbon sources utilized was significantly less inthe disturbed (54%) than in undisturbed areas (95%). Carbonsubstrates important in the discrimination between soil communities includeplant, invertebrate, and microbial derivatives that could not be metabolizedby microbial communities from disturbed sites. Comparisons of totalculturable actinomycetes, bacteria, and fungi reveal no difference in overallnumber of colony forming units (CFU) on disturbed and undisturbed sites, buta marked decrease in actinomycetes on disturbed sites. Biolog andspread-plate data combined indicate a shift in the structure and function ofthe microbial community in campsite soils, which may be a useful indicator ofsoil community disturbance.KEY WORDS: Microbial functional diversity; Anthropogenic disturbance;Recreational impacts; Carbon source profile; Subalpine     

The remaining islands with primary rain forest: A global resource

Islands with large tracts of primary rain forest constitute a distinct complex of terrestrial and marine ecosystems with global significance because of high levels of biological richness or, in the case of oceanic islands, the evolutionary distinctiveness of the organisms that they support. The myriad of small habitat units makes these settings particularly prone to fragmentation and thus problematic for the conservation of biological diversity. Most of the remaining examples of islands with primary rain forest are in the Pacific Rim, particularly in Indonesia, and there are threats from intensive timber harvesting, mining, tourism, and dismemberment of traditional convervation systems. Prospects for inventorying, monitoring, and protecting the remaining islands with relatively pristine successional mosaics of humid forest and shallow marine habitats within a framework global monitoring are explored. Recommendations are made for a program of expanded use of the biosphere reserve designation for rain forest islands and adjacent marine areas.     

Cooperation or conflict? Interagency relationships and the future of biodiversity for US parks and forests

Cooperation between the United States Department of Agriculture (USDA) Forest Service and the United States Department of Interior (USDI) National Park Service is most often advocated to protect biological diversity on national forests and parks, but the agencies, so far, have done little to implement the biodiversity mandates of such laws as the Endangered Species Act and the National Forest Management Act. The ideological and political history of the Forest Service and Park Service is explored to determine the roots of interagency conflicts. Several recent models of cooperative reform are also critiqued and found to be insufficient to stimulate better working relationships. To protect biodiversity, cooperation must be framed within conservation biology and must place primary emphasis on ecosystem patterns and processes as well as on individual species. Increased education of agency managers, ecosystem-level research, local and regional public participation, scientific oversight committees, new legislation, and enlightened leadership also play important roles. Ultimately, management policies must be reframed within a context of ecocentric values.     

BENTHIC INVERTEBRATES IN A NORTH-FLOWING STREAM AND A SOUTH-FLOWING STREAM,BROOKS RANGE,ALASKA1

ABSTRACT: Benthic invertebrate faunas were compared to two fifth-order streams, the Atigun River flowing northward and the Dietrich River flowing southward. Sixty-eight taxa were collected, forty-nine from each stream. Aquatic insects comprised 88% of the taxa and 97% of the individuals from the Dietrich River and 73% of the taxa and 97% of the individuals from the Atigun River. Diptera, especially Chironomidae, were most abundant. Plecoptera, Ephemeroptera, Oligochaeta, Acarina, and Collembola were significant. In both streams the headwaters were dominated by the subfamily Diamesinae which was replaced by Orthocladiinae downstream. Diversity seemed to increase with stream order. Cluster analysis showed a high degree of resemblance between the benthic faunas of the rivers. Faunal resemblance decreased with increasing distance between stations, both within and between the streams. Although some taxa may occur in only one stream, the evidence for faunal resemblance is stronger than for faunal differences. Other studies have shown that differences in total radiation associated with valley aspect affect local climate, hydrology, and distribution of terrestrial plants and animals. However, the benthic faunas of Atigun and Dietrich Rivers were remarkably similar. Factors which operate independently of aspect, possibly freezing solid in winter, may control the occurrence of species in these streams.     

Assessing vulnerability to invasion by nonnative plant species at multiple spatial scales

Basic information on where nonnative plant species have successfully invaded is lacking. We assessed the vulnerability of 22 vegetation types (25 sets of four plots in nine study areas) to nonnative plant invasions in the north–central United States. In general, habitats with high native species richness were more heavily invaded than species-poor habitats, low-elevation areas were more invaded than high-elevation areas, and riparian zones were more invaded than nearby upland sites. For the 100 1000-m² plots (across all vegetation types), 50% of the variation in nonnative species richness was explained by longitude, latitude, native plant species richness, soil total percentage nitrogen, and mean maximum July temperature (n = 100 plots; P < 0.001). At the vegetation-type scale (n = 25 sets of four 1000-m² plots/type), 64% of the variation in nonnative species richness was explained by native plant species richness, elevation, and October to June precipitation (P < 0.001). The foliar cover of nonnative species (log) was strongly positively correlated with the nonnative species richness at the plot scale (r = 0.77, P < 0.001) and vegetation-type scale (r = 0.83, P < 0.001). We concluded that, at the vegetation-type and regional scales in the north–central United States, (1) vegetation types rich in native species are often highly vulnerable to invasion by nonnative plant species; (2) where several nonnative species become established, nonnative species cover can substantially increase; (3) the attributes that maintain high native plant species richness (high light, water, nitrogen, and temperatures) also help maintain nonnative plant species richness; and (4) more care must be taken to preserve native species diversity in highly vulnerable habitats.     

Quantitative Response of Vegetation in Glacial Moraine of Central Himalaya

The snowline in Himalaya is rising ceaselessly due to regional and global climatic change. Upward rising of snowline leads to the formation of moraines. Due to extreme environmental conditions the existing vegetation of the moraine is scanty, rigorous and possesses different ecological adaptation. Ablation zone of the glacier is covered by a thick pile of supra glacial moraines and is characterized by several serrac ice sections, melting into pools of supra glacial lakes because of subsidence and fast degenerating nature of the glacier. Anaphalis triplinervis was observed to have highest importance value in ablation moraine zone. Here the species richness increased remarkably partially due to the invasion of plant species from lower alpine belt. The fresh lateral moraine displays distressed soil features with mosaic type of vegetation. Gaultheria trichophylla is a dominant plant species here and is associated with other stunted and cold resisting species. The old lateral moraine is dominated by Potentilla atrosanguinea with co-dominant species Iris kemaonensis and Danthonia cachemyriana.     

16S rRNA基因技术在环境科学领域中的应用

随着分子生物学的发展，16S rRNA基因技术被逐渐应用到环境科学领域中。目前在环境保护和治理中，该技术主要被用于鉴定污染物的生物降解菌和分析环境样品中的微生物群落多样性，由于它不必将微生物培养分离出来，也就避免了在培养过程中可能出现的微生物去失的情况。本文对16S rRNA基因技术及其在环境科学领域中的应用现状和发展作了一简要介绍，并对16S rRNA基因技术存在的不足进行了讨论。     

火对野生动物的生态作用

本文主要阐述了自然生态系统中，火对野生动物的直接影响及其通过改变动物的栖息环境、食物组成等因素给动物带来或可能带来的间接影响。强调火烧给动物生物多样性带来的威胁。最后探讨了人类控制火因子为人类服务的问题。     

Biotechnology is compatible with sustainable agriculture

Biotechnology can provide appropriate new tools for use in solution of specific problems in sustainable agriculture. Its usefulness will depend in large part on the degree to which sustainable agriculturists understand the utility of biotechnology and apply it toward ends they deem important. Biotechnology can give little assistance to sustainable agriculture in the short term. It can be more useful in the medium term, and it could be highly useful in the long term as an integral part of the art and science of plant breeding and other components of sustainable agriculture systems.     

管理者与员工在不安全行为控制认识上的差异研究

很多煤矿事故的发生都与管理者的不恰当控制行为有关。如果管理者对不同控制措施和手段的认识存在偏差或错误,势必影响其控制行为选择的科学性,进而影响实际的控制效果。通过对煤矿管理者和员工的问卷调查和研究,实证地分析了管理者和员工对不安全行为控制问题的认识,及其在该问题上的认识差异。研究表明,管理者在一些不安全行为控制措施和手段的认识上与员工存在偏差,管理者选择的控制行为与员工认为应该实施的控制行为间存在差异。要提高对员工不安全行为的控制效果,管理者应根据员工的认识来选择自己的不安全行为控制措施和手段。