南岳水濂洞景区规划设计初探

水濂洞是南岳风景区系中的一个重要组成部分,本文就水濂洞景区的规划、设计和建筑提出了一些看法。指出在设计时,要重点突出:静、险、古、幽、奇五个特点。     

Examining Landscape Dynamics at a Watershed Scale Using Landsat TM Imagery for Detection of Wintering Hooded Crane Decline in Yashiro,Japan

It is usually inappropriate to define rectangular land areas or administrative units as the extent for quantifying landscapes that possess hierarchical structure. As a functional unit established by geophysical relationships, the watershed is one of many natural scales in the hierarchical landscape. We examined the dynamics of the Yashiro watershed of Japan at the landscape level using pattern metrics based on Landsat thematic mapper (TM) imagery from 1985 to 1998. This watershed provides important habitats for the hooded crane (Grus monachus), a vulnerable species. While its world population has remained stable, the number wintering at Yashiro has declined in recent years. Changes in landscape metrics reveal that the spatial pattern within the watershed underwent homogenization due to depopulation of local people and shifts in local energy requirements and forest management policy at Yashiro. Specific changes include: a decrease in bare land area from 6.2% to 1.0% of the landscape, increased forest cover from 69.2% to 76.1%, reduction in patch number from 1194 to 616 and enlarged mean patch size, and a decrease in total edge from 223,740 m to 158,040 m. The rate of change in landscape metrics indicates a rapid change towards homogeneity in the landscape since 1990. The temporal changes in hooded crane populations corresponded to the changes in landscape. An alternative explanation has been proposed that decline of the species is influenced by landscape dynamics affecting both habitat selection and food resources. Conservation at the watershed scale is suggested to be complementary to the current conservation measures of the species.     

Landscape Metrics for Assessment of Landscape Destruction and Rehabilitation

This investigation tested the usefulness of geometry-based landscape metrics for monitoring landscapes in a heavily disturbed environment. Research was carried out in a 75 sq km study area in Saxony, eastern Germany, where the landscape has been affected by surface mining and agricultural intensification. Landscape metrics were calculated from digital maps (1912, 1944, 1973, 1989) for the entire study area and for subregions (river valleys, plains), which were defined using the original geology and topography of the region. Correlation and factor analyses were used to select a set of landscape metrics suitable for landscape monitoring. Little land-use change occurred in the first half of the century, but political decisions and technological developments led to considerable change later. Metrics showed a similar pattern with almost no change between 1912 and 1944, but dramatic changes after 1944. Nonparametric statistical methods were used to test whether metrics differed between river valleys and plains. Significant differences in the metrics for these regions were found in the early maps (1912, 1944), but these differences were not significant in 1973 or 1989. These findings indicate that anthropogenic influences created a more homogeneous landscape.     

利用森林景观优势 发展森林旅游业

森林旅游资源的开发与利用是当今各国森林公园建设所面临的一个重要问题。本文就如何克分利用森林旅游资源,发挥森林景观优势开展多种旅游项目,提出了自己的看法与对策,为发展我国旅游业提供了理论依据。     

城市景观水体中腐殖酸的臭氧氧化去除

以南京师范大学德风园池底泥中提取的腐殖酸(HA)为研究对象,采用臭氧氧化技术对其进行去除,对初始pH值、混合气体流量、腐殖酸(HA)初始浓度以及水中常见离子等因素对去除效果的影响进行了研究。实验结果表明:腐殖酸(HA)的去除率随初始pH值的升高而提高,随混合气体流量减少而提高;当腐殖酸(HA)初始浓度为5 mg/L时,反应过程中溶液的UV254升高,紫外扫描结果发现,溶液在200~220 nm内出现杂乱的吸收峰,表明有新物质生成;水中常见的无机阴离子(CO32-、HCO3-)和二价金属离子(Ca2+、Cu2+)的存在会降低臭氧对腐殖酸(HA)的去除率。     

融雪剂对园林植物种子萌发的影响

使用融雪剂是高纬度城市冬季除雪的主要措施之一,但融雪剂中含有的盐类物质可以对园林植物造成伤害。在此研究了融雪剂对刺（Robinia pseudoacacia）、万寿菊（Tagetes erecta）、矮紫薇（Lagerstroemia indiea’Petite pinkie＇）、草地早熟禾（Poa pratensis）、侧柏（Platycladus orientalis）种子发芽率和相对受害率的影响。试验结果表明：5种植物种子的发芽率随融雪剂浓度的升高而降低．相对受害率则随融雪剂浓度升高而增大。其中草地早熟禾种子时融雪剂最敏感,可以用草地早熟禾种子萌发为指示,间接检验融雪剂对植物的伤害程度。     

浅谈齐齐哈尔市大气环境污染特征及其防治对策

齐齐哈尔市城区大气环境污染物主要为降尘、可吸入颗粒物(PM10)、SO2、NO2。其中降尘、PM10为首要污染物,降尘、PM10污染源来自煤烟尘、城市扬尘、机动车尾气尘等方面,属于复合污染类型,同时,人为活动所形成的二次扬尘正成为城市颗粒物污染的主要来源。因此,控制城区大气污染必须采取综合措施。     

Phylogeny of Collembola based on cuticular compounds:inherent usefulness and limitation of a character type

The phylogeny of Collembola, originally discussed from a morphological point of view, has more recently benefited from novel insights brought by molecular analyses. Both morphological and molecular characters produced a well-resolved phylogenetic hypothesis including all orders, most families, and a large number of genera. However, several conflicting points exist between molecular and morphological data, and new characters are clearly needed to resolve these inconsistencies. In this study the usefulness of a new character type not previously used in the phylogenetic study of Collembola was tested: the epicuticular chemical compounds. Our phylogenetic analysis was based on 380 compounds from 26 Collembola species. The results show good resolution for terminal branches but not for internal nodes. This is probably due to the partial involvement of epicuticular lipids in ecological functions such as water conservation and sexual attraction. Thus, this character type is appropriate for reconstructing phylogenetic relationships among recently diversified groups. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Fragmentation drives tropical forest fragments to early successional states: A modelling study for Brazilian Atlantic forests

Land use leads to massive habitat destruction and fragmentation in tropical forests. Despite its global dimensions the effects of fragmentation on ecosystem dynamics are not well understood due to the complexity of the problem. We present a simulation analysis performed by the individual-based model FORMIND. The model was applied to the Brazilian Atlantic Forest, one of the world's biodiversity hot spots, at the Plateau of São Paulo. This study investigates the long-term effects of fragmentation processes on structure and dynamics of different sized remnant tropical forest fragments (1-100 ha) at community and plant functional type (PFT) level. We disentangle the interplay of single effects of different key fragmentation processes (edge mortality, increased mortality of large trees, local seed loss and external seed rain) using simulation experiments in a full factorial design.Our analysis reveals that particularly small forest fragments below 25 ha suffer substantial structural changes, biomass and biodiversity loss in the long term. At community level biomass is reduced up to 60%. Two thirds of the mid- and late-successional species groups, especially shade-tolerant (late successional climax) species groups are prone of extinction in small fragments. The shade-tolerant species groups were most strongly affected; its tree number was reduced more than 60% mainly by increased edge mortality. This process proved to be the most powerful of those investigated, explaining alone more than 80% of the changes observed for this group. External seed rain was able to compensate approximately 30% of the observed fragmentation effects for shade-tolerant species.Our results suggest that tropical forest fragments will suffer strong structural changes in the long term, leading to tree species impoverishment. They may reach a new equilibrium with a substantially reduced subset of the initial species pool, and are driven towards an earlier successional state. The natural regeneration potential of a landscape scattered with forest fragments appears to be limited, as external seed rain is not able to fully compensate for the observed fragmentation-induced changes. Our findings suggest basic recommendations for the management of fragmented tropical forest landscapes.     

Landscape--wildfire interactions in southern Europe: implications for landscape management

Every year approximately half a million hectares of land are burned by wildfires in southern Europe, causing large ecological and socio-economic impacts. Climate and land use changes in the last decades have increased fire risk and danger. In this paper we review the available scientific knowledge on the relationships between landscape and wildfires in the Mediterranean region, with a focus on its application for defining landscape management guidelines and policies that could be adopted in order to promote landscapes with lower fire hazard. The main findings are that (1) socio-economic drivers have favoured land cover changes contributing to increasing fire hazard in the last decades, (2) large wildfires are becoming more frequent, (3) increased fire frequency is promoting homogeneous landscapes covered by fire-prone shrublands; (4) landscape planning to reduce fuel loads may be successful only if fire weather conditions are not extreme. The challenges to address these problems and the policy and landscape management responses that should be adopted are discussed, along with major knowledge gaps.