近来宿迁地震台地磁观测所受干扰之分析

2006年7月初期,宿迁地震台开工新建一监测楼,楼中使用了很多钢筋和其它铁磁性材料,由于它离地磁房较近,这些铁磁性材料所产生的磁场给该台的地磁观测造成了很大的干扰.本文就宿迁台地磁场的观测情况、根据IAGA推荐的理论公式计算理论上的干扰、实际产生的干扰效果等方面给出简单陈述,并就其中的因果关系做出简单的分析和推理,以求对这次干扰做一合理的解释.     

自然保护区学研究与景观生态学基本理论

本文尝试把景观生态学思想融于自然保护区理论中，较系统地论述了以景观结构与功能原理、景观异质性理论、景观格局理论、等级—尺度理论、干扰学说、生物多样性原理以及景观稳定性理论等景观生态学的基本理论为基础的自然保护区学的研究     

Effects of Tourists on Behavior and Demography of Olympic Marmots

Abstract:  If changes in animal behavior resulting from direct human disturbance negatively affect the persistence of a given species or population, then these behavioral changes must necessarily lead to reduced demographic performance. We tested for the effects of human disturbance on Olympic marmots ( Marmota olympus ), a large ground-dwelling squirrel that has disappeared from several areas where recreation levels are high. We assessed the degree to which antipredator and foraging behavior and demographic rates (survival and reproduction) differed between sites with high recreation levels (high use) and those with little or no recreation (low use). Compared with the marmots at low-use sites, marmots at high-use sites displayed significantly reduced responses to human approach, which could be construed as successful accommodation of disturbance or as a decrease in predator awareness. The marmots at high-use sites also looked up more often while foraging, which suggests an increased wariness. Marmots at both types of sites had comparable reproductive and survival rates and were in similar body condition. Until now, the supposition that marmots can adjust their behavior to avoid negative demographic consequences when confronted with heavy tourism has been based on potentially ambiguous behavioral data. Our results support this hypothesis in the case of Olympic marmots and demonstrate the importance of considering demographic data when evaluating the impacts of recreation on animal populations.     

南极菲尔德斯半岛空气微生物含量初报

南极菲尔德斯半岛外空气微生物的采样站分作３种类型，类型Ｉ．科考站及附近区域，类型Ⅱ．大型动物出没区，类型Ⅲ大型动物少，且保持荒凉状态区，结果显示，Ｉ类型区室外空气微生物含量明显高于Ⅲ类型区，平均Ｉ区有４９９４ｃｆｕ．ｍ＾－３，Ⅲ区仅１６ｃｕｆ．ｍ＾－３，结果提示，菲尔德斯半岛空气微生物已受到人类活动的干扰。     

Agricultural land-use change and ash (<Emphasis Type="Italic">Fraxinus excelsior</Emphasis> L.) colonization in Pyrenean landscapes: an interdisciplinary case study

Changes in agricultural land use are responsible for significant modifications in mountain landscapes. This study is part of an interdisciplinary research on the processes and consequences of spontaneous afforestation of Pyrenean landscapes by ash, and the possibilities for its management. We address the relationships between vegetation dynamics and land-use change from the combination of an agricultural study of change in farm management and an ecological study of grassland colonization by ash. In the framework of a village case study, we characterized parcels management and land-use histories, and analyzed the dynamics of the composition of grassland vegetation communities. From a joint analysis of the results obtained in each discipline, we discuss the limitations and complementarities of the two approaches for the interdisciplinary assessment of the afforestation process.     

基于岩体扰动参数的边坡结构优化

为了研究岩体扰动参数对边坡稳定性的影响,根据某露天边坡岩体物理性质及坡体钻孔勘探结果,分析了边坡体各岩组在不同扰动参数下的强度弱化过程;考虑由扰动产生的节理裂隙对边坡稳定性的影响,通过Phase^2软件对仿真计算模型进行了不同扰动程度的区域划分;同时提出了一种用于直观表征露天整天边坡稳定性的安全系数“玫瑰花”图。结果表明:各边帮受节理切割和爆破扰动的影响,稳定性差异较大,部分边帮安全储备充足,仍存在优化空间;节理裂隙几何位置对边坡失稳滑移面具有控制作用,对于近乎顺层岩质边坡,其破坏主要沿节理面剪切滑移;对于具有浅埋倾覆节理面边坡,由于岩体强度较高易发生倾倒破坏,所绘制的边坡安全系数“玫瑰花”图可直观表征露天边坡整体稳定性,考虑局部扰动影响对边坡稳定性分析进行精细化表征,为矿山边坡角度的进一步优化提供了一定的参考指标。     

Scale-dependent inconsistencies in the effects of trampling on a forest understory community

The response of forest understory vegetation to trampling applied at different temporal and spatial scales was determined in a cliff-edge forest in Ontario, Canada. Three frequencies (0, 50, 500 passes per year) of short-term trampling (one year) were applied to plots previously undisturbed. Existing trails that had received three frequencies (approx. 100, 500, 25,000 passes per year) of long-term trampling (18 years) were also studied. Community composition, species richness, and individual species frequency were recorded in plots within 4 m and (or) 1 m of the patch centerline. The quantitative and qualitative form of plant response to increased trampling was compared for short-term and long-term treatments, both within 4 m and within 1 m of the path centerline, to judge the consistency of trampling effects at different temporal and spatial scales. As trampling frequency increased, community composition changed progressively, but consistently, in plots both within 4 m and 1 m of the path centerline. Species richness was less affected by trampling and only decreased within 1 m of the path centerline at the highest level of trampling (25,000 passes per season for 18 years). Effects of trampling on individual species frequency were much less consistent at different temporal and spatial scales of trampling. The scale-dependence results suggest that field workers and resource managers both should try explicitly to include and define multiple scale components when trying to ascertain the response of vegetation to human disturbance factors.     

EFFECTS OF SIMULATED CANOPY COVER AND ANIMAL DISTURBANCES ON RILL AND INTERRILL EROSION1

ABSTRACT: A rainfall simulator was used on runoff plots to study the effects of simulated canopy cover, trampling disturbance, and soil type on nil and interrill erosion. Sandy loam soil was more erodible than clay loam soil. Furthermore, the simulated canopy cover signffi-Soilfactorsrelatedtonil cantly influenced nil and interrill erosion. The effect of trampling on rill and interrill erosion varied with soil type (clay loam versus sandy loam) and erosion type (nh versus interrill erosion). On large plots, where both nil and internill erosion were involved, 30 percent trampling significantly increased soil loss. However, on small plots, 30 percent trampling significantly reduced interrill erosion.     

Simulated grazing responses on the proposed prairies National Park

The tallgrass prairie version of the ELM Grassland Model was used to evaluate the potential impact of establishing a tallgrass prairie National Park in the Flint Hills region of Kansas. This total ecosystem model simulates (a) the flow of water, heat, nitrogen, and phosphorus through the ecosystem and(b) the biomass dynamics of plants and consumers. It was specifically developed to study the effects of levels and types of herbivory, climatic variation, and fertilization upon grassland ecosystems. The model was used to simulate the impact of building up herds of bison, elk, antelope, and wolves on a tallgrass prairie. The results show that the grazing levels in the park should not be decreased below the prepark grazing levels (moderate grazing with cattle) and that the final grazing levels in the park could be maintained at a slightly higher level than the prepark grazing levels.