论园林树木栽培学(各论)的精讲教学法

园林树木栽培学是一门实践性很强的有关园林绿化领域的专业课、必修课.1995年以来,本人在园林树木栽培学各论教学中尝试重点讲解、课堂点评的教学方法,取得了较好的教学效果.     

垂直流人工湿地水力学特性研究

通过示踪剂实验从停留时间分布（RTD）曲线及其统计特征值等方面对垂直流人工湿地的水力学特性进行了定性和定量的分析。研究表明水流在垂直流人工湿地中的流动是一种非理想的不均匀流动,存在一定的死区和水流的扩散;垂直流人工湿地较大的死区率与其表面布水的不均匀性有关,这也可能是其死区率大于表流人工湿地的最主要的原因。实验还表明,进水流量对垂直流人工湿地停留时间分布影响较大,随着进水流量的增加,平均停留时间减小,但标准平均停留时间增大,死区率减小;当进水流量为15L／h（水力负荷为620mm／d）时,水流在湿地中的散度最大,水流更接近全混流,不利于污染物的降解。     

Effects of Road Networks on Bird Populations

Abstract: One potential contributor to the worldwide decline of bird populations is the increasing prevalence of roads, which have several negative effects on birds and other vertebrates. We synthesized the results of studies and reviews that explore the effects of roads on birds with an emphasis on paved roads. The well‐known direct effects of roads on birds include habitat loss and fragmentation, vehicle‐caused mortality, pollution, and poisoning. Nevertheless, indirect effects may exert a greater influence on bird populations. These effects include noise, artificial light, barriers to movement, and edges associated with roads. Moreover, indirect and direct effects may act synergistically to cause decreases in population density and species richness. Of the many effects of roads, it appears that road mortality and traffic noise may have the most substantial effects on birds relative to other effects and taxonomic groups. Potential measures for mitigating the detrimental effects of roads include noise‐reduction strategies and changes to roadway lighting and vegetation and traffic flow. Road networks and traffic volumes are projected to increase in many countries around the world. Increasing habitat loss and fragmentation and predicted species distribution shifts due to climate change are likely to compound the overall effects of roads on birds.     

EFFECTS OF SELECTED HERBICIDES ON BACTERIAL POPULATIONS IN NONTREATED AND TREATED WATER1

ABSTRACT: Bacterial populations in nontreated and herbicide-treated waters were subjected to three different herbicides. Diuron, dichlobenil, and diquat were added (100 mg/l) to water samples from two fresh water lakes and two herbicide-treated ponds. Total numbers of bacteria were monitored. Bacterial populations in fresh lake water decreased after herbicide additions; however, final populations were significantly greater than the controls. Similar observations were recorded for bacteria in dichlobenil- and diuron-treated waters. Selective enrichment is probably expressed in these experiments.     

Modeling of power plant impacts on fish populations

A simulation model was developed for assessing the effects of power plant impacts on fish populations. The model was based on biomass changes in a fish population that divided into 4 life stages: eggs, larvae, juveniles, and adults. Metabolism of fish was included in the model as assimilation and respiration with the effects of temperature push-pull regulation. A cohort technique was used for life stage transfers in the young stages. Compensation was included in terms of density-dependent mortality of the young fish. Power plant impacts on a fish population included entrainment (eggs and larvae) and impingement (juveniles and adults).The model was applied to the gizzard shad (Dorosoma cepedianum) population in Pool 14 of the Mississippi River in Illinois and lowa. The nearby nuclear power plant, the Quad-Cities Station, is located on the Illinois side. The simulation of the model with the 1976 field data estimates of the power plant entrainment and impingement predicted a 10 percent potential reduction of the population over 30 years. The simulated reduction of the population with the effects of different river flows showed that the result with the 1976 river flow data gave 1.5 times higher reduction than the results with data of other plant operation years, 1972 through 1975. Because the 1976 data recorded low river flow, the 10 percent reduction quoted above may be high.     

Resident participation in post-Lushan earthquake housing reconstruction: a multi-stage field research method-based inquiry

In April 2013, a 7.0?Mw earthquake struck in Lushan County, Sichuan Province, China, causing serious housing damage. Housing reconstruction is a crucial part of disaster recovery, and resident participation has been recognized as a key part of reconstruction success. This paper examined housing reconstruction resident participation in the post-Lushan earthquake period as a multi-stage problem based on multi-stakeholder collaborative perspectives, which covered emergency shelter, temporary housing and permanent housing stages. Multi-stage field research was conducted in the affected areas, and the residents were found to be fully involved in the reconstruction with a ‘high – medium – high' distribution across the three stages. Resident participation experiences were summarized in terms of previous earthquake education, NGO participation and community-based organization functions, and the reasons discussed, such as civic awareness and civic rights. Problems regarding improper reconstruction and cultural conflicts were also examined and valuable suggestions given.     

An Adaptive‐Management Framework for Optimal Control of Hiking Near Golden Eagle Nests in Denali National Park

Abstract: Unintended effects of recreational activities in protected areas are of growing concern. We used an adaptive‐management framework to develop guidelines for optimally managing hiking activities to maintain desired levels of territory occupancy and reproductive success of Golden Eagles (Aquila chrysaetos) in Denali National Park (Alaska, U.S.A.). The management decision was to restrict human access (hikers) to particular nesting territories to reduce disturbance. The management objective was to minimize restrictions on hikers while maintaining reproductive performance of eagles above some specified level. We based our decision analysis on predictive models of site occupancy of eagles developed using a combination of expert opinion and data collected from 93 eagle territories over 20 years. The best predictive model showed that restricting human access to eagle territories had little effect on occupancy dynamics. However, when considering important sources of uncertainty in the models, including environmental stochasticity, imperfect detection of hares on which eagles prey, and model uncertainty, restricting access of territories to hikers improved eagle reproduction substantially. An adaptive management framework such as ours may help reduce uncertainty of the effects of hiking activities on Golden Eagles.     

Natural Movements of Tagged Beavers in Tyva

Ninety-three beavers were tagged in 1998–2000 on the Azas River (Tyva Republic), and 28 returns were obtained within one to two years. The results of the study indicated that, unfavorable environment notwithstanding, most beavers did not move outside their settlements. Animals under two years of age were especially active. Females were more resident, whereas males migrated over longer distances. The section of the Azas River with numerous rapids was not an insuperable obstacle for the animals; genetic exchange between the upper and lower subpopulations was found to occur through this section.     

Anaerobic phenanthrene biodegradation with four kinds of electron acceptors enriched from the same mixed inoculum and exploration of metabolic pathways

Anaerobic phenanthrene biodegradation enriched process was described in detail. The enriched bacterial communities were characterized under four redox conditions. The enriched archaeal communities were stated under high percentage conditions. Relatively intact pathways of anaerobic phenanthrene biodegradation were proposed. Polycyclic aromatic hydrocarbons (PAHs) are widespread and persistent contaminants worldwide, especially in environments devoid of molecular oxygen. For lack of molecular oxygen, researchers enhanced anaerobic zones PAHs biodegradation by adding sulfate, bicarbonate, nitrate, and iron. However, microbial community reports of them were limited, and information of metabolites was poor except two-ring PAH, naphthalene. Here, we reported on four phenanthrene-degrading enrichment cultures with sulfate, bicarbonate, nitrate, and iron as electron acceptors from the same initial inoculum. The high-to-low order of the anaerobic phenanthrene biodegradation rate was the nitrate-reducing conditions>sulfate-reducing conditions>methanogenic conditions>iron-reducing conditions. The dominant bacteria populations were Desulfobacteraceae, Anaerolinaceae, and Thermodesulfobiaceae under sulfate-reducing conditions; Moraxellaceae, Clostridiaceae, and Comamonadaceae under methanogenic conditions; Rhodobacteraceae, Planococcaceae, and Xanthomonadaceae under nitrate-reducing conditions; and Geobacteraceae, Carnobacteriaceae, and Anaerolinaceae under iron-reducing conditions, respectively. Principal component analysis (PCA) indicated that bacteria populations of longtime enriched cultures with four electron acceptors all obtained significant changes from original inoculum, and bacterial communities were similar under nitrate-reducing and iron-reducing conditions. Archaea accounted for a high percentage under iron-reducing and methanogenic conditions, and Methanosarcinaceae and Methanobacteriaceae, as well as Methanobacteriaceae, were the dominant archaea populations under iron-reducing and methanogenic conditions. The key steps of phenanthrene biodegradation under four reducing conditions were carboxylation, further ring system reduction, and ring cleavage.     

Measuring participation by socially vulnerable groups in hazard mitigation planning,Bertie County,North Carolina

In accordance with the Disaster Mitigation Act, most US counties have a hazard mitigation plan (HMP) to reduce future disaster losses. HMPs are important as they can be used to proactively assess risk, direct future development, raise awareness and build consensus. Using a population-based sample, we interviewed residents of Bertie County, NC, about their awareness of and participation in the HMP process to determine if demographics, social vulnerability or hazard vulnerability were associated with increased awareness or participation. We also assessed whether these factors were associated with knowledge of policy changes and investments that were adopted in the HMP. Overall, the unemployed were the only group less likely to report awareness of or participation in HMP development. African-Americans, mobile home residents, the poor, short-term residents and those with less disaster experience were less likely to be aware of policies and investments prioritised in the HMP. Targeted efforts to increase awareness could potentially improve disaster outcomes among vulnerable populations.