Ski slope vegetation in central Honshu,Japan

To determine the status of the vegetation of ski slopes in northeastern-central Honshu, Japan, 94 plots (2×2 m) were set up on five ski areas (101–520 m elevation) which were established between 1945 and 1985 by forest clear-cutting, land modification, and seeding. Six vegetation types were recognized: five grasslands dominated byDigitaria adscendens, Miscanthus sinensis, Zoysia japonica, Festuca rubra, andPteridium aquilinum var.latiusculum, respectively, and bare areas of very low to no vegetation cover. Of the dominant species,F. rubra is the only introduced species; it does not, however, appear to persist. After the introduced grassland declinesM. sinensis or annual grasslands develop. Native plants, especially woody species, can establish inM. sinensis grassland but do not establish in the other grasslands. It is concluded that the introduction of exotic species is inappropriate to maintain ski slope vegetation, and the development ofM. sinensis grassland is desirable to promote natural revegetation.     

Opportunities and constraints for development and conservation: Teller County/Woodland Park growth management plan

This is the second of three articles prepared to explain the Teller County growth management process. As part of an ongoing growth management process in Teller County, Colorado, opportunities and constraints for development and conservation were identified. The scenic mountain county faces a number of issues because of growth. The recognition of those issues has resulted in the goal to direct future growth to the most appropriate and cost-effective places. To determine those places that are best for new development, thorough ecological inventories were conducted for the entire county as well as for the City of Woodland Park area. From these inventories, environmentally sensitive areas were identified. The environmentally sensitive areas were considered constraints in conducting suitability analyses for a variety of potential land uses. The suitability analyses resulted in the identification of opportunities for future growth in Teller County generally as well as the more specific Woodland Park planning area. This article, like the other two, is part of a reflective analysis by the planners who were involved. Paper 2 in a series 3.     

Patterns of development and succession of vegetated hummocks in slacks of the Alexandria coastal dune field, South Africa

Dune hummocks (small aeolian dunes formed by sand deposition in and around pioneer plants) are the smallest vegetated dune unit; they occur along the entire South African coastline but are poorly studied. Structural properties and distribution of the two main hummock-forming plants:Arctotheca populifolia (a pioneer species with fast growth rate and rapid turnover) andGazania rigens (a later colonizer with slower growth) were investigated. A marked vegetation succession exists across the floor of the slack as a result of the migration of transverse dune ridges across the slack.Arctotheca hummocks were initiated on the newly exposed eastern margin of the slack, and were replaced about midway across the width of the slack byGazania hummocks. Hummocks increased in size with distance from the eastern side of the slack.Gazania hummocks attain a greater vegetation height, support a greater vegetation complexity and mass, and attain a larger maximum size thanArctotheca hummocks. Succession, defined as both the replacement of plant species as well as site modification within the plants over time, was evident. Since the growth form and dynamics determine (1) the ability of plants to trap wind-borne soil and detritus, (2) the shape of the hummocks, and (3) the habitat complexity available to spiders and insects, the ecology of the hummocks is probably determined largely by the vegetation characteristics of the hummock-forming plants.     

An early warning method of landscape ecological security in rapid urbanizing coastal areas and its application in Xiamen, China

Based on the Pressure-State-Response (P-S-R) approach, an index system for landscape ecological security (LES) was suggested using three dimensions, six factors, and three weights. The indicators in the system were divided into two groups: spatial interpolation (acquired by the remote sensing data) and non-spatial interpolation (acquired by consultation with experts). According to data of 2003 and 2006, coupled with current tendencies, the early warning method was classified into four categories: security and degradation, sub-security and slow degradation, sub-security and rapid degradation, and insecurity. Our research with early warning method finds three interesting phenomena: (1) mean value of LES in 2003 was 0.586, indicating medium security; while in 2006 it was 0.650, an upper medium security. The LES level within each districts of Xiamen in 2006 was better than the level in 2003. In terms of LES, the comprehensive condition within each district of Xiamen in 2006 was enhanced compared with 2003. Overall, there was improvement in 80.5% of areas from 2003 to 2006, showing promising signs of positive development. (2) The LES of Xiang’an District and Jimei District were in stages of high early warning given that the percentage of land in these districts that showed symptoms of insecurity and degradation was 41.03 and 34.89%, respectively. (3) On the whole, the areas that showed notable signs of insecurity and rapid landscape, and which can already be identified as early warning areas requiring immediate attention, correspond closely with the distribution of coastal industrial parks in these regions. In conclusion, the consequences of rapid industrialization and urbanization are far reaching and affect local and regional ecological security.     

Persistent organochlorine contaminants in hair samples of Northern Poland population, 1968-2009

The European regulation on chemicals, REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals), came into force on 1 June 2007. With pre-registration complete in 2008, data for these substances may provide an overview of the expected chemical space and its characteristics. In this paper, using various in silico computation tools, we evaluate 48 782 neutral organic compounds from the list to identify hazardous and safe compounds. Two different classification schemes (modified Verhaar and ECOSAR) identified between 17% and 25% of the compounds as expressing only baseline toxicity (narcosis). A smaller portion could be identified as reactive (19%) or specifically acting (2.7%), while the majority were non-assigned (61%). Overall environmental persistence, bioaccumulation and long-range transport potential were evaluated using structure-activity relationships and a multimedia fugacity-based model. A surprisingly high proportion of compounds (20%), mainly aromatic and halogenated, had a very high estimated persistence (>195 d). The proportion of compounds with a very high estimated bioconcentration or bioaccumulation factor (>5000) was substantially less (6.9%). Finally, a list was compiled of those compounds within the applicability domain of the models used, meeting both persistence and bioaccumulation criteria, and with a long-range transport potential comparable to PCB. This list of 68 potential persistent organic pollutants contained many well-known compounds (all halogenated), but notably also five fluorinated compounds that were not included in the EINECS inventory. This study demonstrates the usability of in silico tools for identification of potentially environmentally hazardous chemicals.     

单甲脒在土壤中的降解及持久性研究

本文对四种不同类型土壤中单甲脒及其盐酸盐在厌氧与好氧条件下的降解动态及其残留进行了研究。结果表明单甲脒及其盐酸盐均属不稳定的化合物，单甲脒在土壤中的半衰期为４．６－９．１ｄ，其盐酸盐的半衰期为２．０－６．２ｄ。结果还表明单甲脒盐酸盐在厌氧条件下较在好氧条件下降解缓慢；在厌氧条件时，土壤的ｐＨ值对其降解影响较大。在相同条件下，单甲脒比它的盐酸盐酸盐降解慢，其降解速率与土壤ｐＨ值无关。     

土地利用对流域氮素记忆效应的影响研究

"记忆效应"是一些流域实行了多年的氮污染控制实践却仍未见成效的主要原因之一.然而,目前对流域氮素记忆效应的认识还很有限.本研究利用温州市珊溪水源地13个集水区近5年的河流TN浓度逐月监测数据,运用重标极差(R/S)分析和Spearman秩相关分析方法,探讨了土地利用对流域氮素记忆效应的影响.结果表明,河流TN平均浓度与耕地(r=0.495,p=0.086)和建设用地(r=0.692,p=0.009)面积比例正相关,与林地(r=-0.604,p=0.029)面积比例显著负相关,与园地(r=-0.039,p=0.900)、未利用地(r=-0.176,p=0.566)、集水区面积(r=-0.335,p=0.263)和河网密度(r=0.148,p=0.629)的相关性不显著.13条入库支流TN浓度序列的Hurst指数变异范围为0.33~0.72,意味着其中11个集水区具有显著的氮素记忆效应(0.5Hurst指数1.0),而其余2个集水区不显著(0Hurst指数0.5).Hurst指数与耕地(r=-0.482,p=0.095)和建设用地(r=-0.311,p=0.301)面积比例均负相关,而与园地(r=0.479,p=0.098)和林地(r=0.510,p=0.075)面积比例正相关.同时,Hurst指数与集水区面积大小(r=0.118,p=0.700)和未利用地面积比例(r=0.032,p=0.917)的相关性不显著,而与河网密度负相关(r=-0.529,p=0.063).流域内"源"功能为主土地利用面积的增加和氮输移效率的提高加剧了河流氮污染,而对氮素记忆效应的作用则相反.因此,尽管增加"汇"景观面积、降低氮输移效率能缓解河流氮污染,但"汇"景观中截留的遗留氮对河流氮浓度会造成更长时间的影响.     

河口人工湿地植物配置与景观建设维护研究——以沈阳市辉山明渠河口湿地为例

以沈阳市辉山明渠入浑河河口湿地为研究对象,通过植物适应性分析、湿地植物选择、湿地植物优化配置、景观合理性配置等综合调控措施,使辉山明渠入浑河水质得到有效改善、湿地生物多样性得到恢复、人工湿地生态系统稳定性增强、形成独具特色的河口湿地景观。