搞好生态建设,转移农村剩余劳动力

大量闲置劳动力会造成巨大生态压力,加剧生态退化,但只要转移消化得当,便能化为强大的力量和优势。本文从区域→行业→企业→家庭→生态建设联合体五个层次和角度,对各种有效的和有可能的转移消化闲置劳动力生态建设途径进行了探索。     

Dynamics and Causation of Environmental Equity, Locally Unwanted Land Uses, and Neighborhood Changes

/ Why are some environmental risks distributed disproportionately in the neighborhoods of the minorities and the poor? A hypothesis was proposed in a recent study that market dynamics contributed to the current environmental inequity. That is, locally unwanted land uses (LULUs) make the host communities home to more poor people and people of color. This hypothesis was allegedly supported by a Houston case study, whereby its author analyzed the postsiting changes of the socioeconomic characteristics of the neighborhoods surrounding solid waste facilities. I argue that such an analysis of postsiting changes alone is insufficient to test the causation hypothesis. Instead, I propose a conceptual framework for analysis of environmental equity dynamics and causation. I suggest that the presiting neighborhood dynamics and the characteristics of control neighborhoods be analyzed as the first test for the causation hypothesis. Furthermore, I present theories of neighborhood change and then examine alternative hypotheses that these theories offer for explaining neighborhood changes and for the roles of LULUs in neighborhood changes. These alternative hypotheses should be examined when analyzing the relationship between LULUs and neighborhood changes in a metropolitan area. Using this framework of analysis, I revisited the Houston case. First, I found no evidence that provided support for the hypothesis that the presence of LULUs made the neighborhoods home to more blacks and poor people, contrary to the conclusion made by the previous study. Second, I examined alternative hypotheses for explaining neighborhood changes-invasion-succession, other push forces, and neighborhood life-cycle; the former two might offer better explanation.KEY WORDS: Environmental equity and justice; Locally unwanted lane uses; Siting; Market dynamics; Invasion-succession; Neighborhood changes     

A Marine Pollution Study of Northeast Coastal Water Off Taiwan Island

The coastal water of northeast Taiwan island, called 'Yin-Yang Hai' for its distinct yellow colour compared with blue offshore water, was investigated from 1989 to 1990 by the authors. Biological study showed the dominant species of plankton to be Copepoda, Cladocera, planktonic eggs and Diatoma. Dominant species of benthos were young crabs, Amphipoda and Annelida, with Amphipoda usually occurring in heavily polluted areas. Heavy metal data showed that the concentration of copper was high. the copper and iron concentration in algae of the intertidal zone was also high. the concentrations of iron and copper in inshore water were also higher than in offshore water. By comparison of the pH and salinity distribution of this area, we conclude that this coastal water has been polluted by acid waste water from coastal industry. the suspended solids concentration in sea water is high. Flocculation occurring at the boundary of fresh and saline water might be a reason for the distinct yellow colour of the water of this area. Further study is required.     

Effects of high temperature on larval development and metamorphosis of Arachnoides placenta (Echinodermata: Echinoidea)

Adults of the sea urchin Arachnoides placenta (L.) were induced to spawn, and eggs were fertilized at 28°C in September 1989. After 5 min, eggs were transferred to 28, 31, 34, or 37°C and reared to metamorphosis. Embryos were observed at 20-min intervals during the first 2 h; larvae were observed daily. The cleavage was higher at higher temperatures. Embryos reared at 28°C were still at the 4th cleavage (16-cell stage) after 100 min, while those at 34°C had reached the 5th cleavage (32-cell stage). All embryos reared at 37°C died on the second day. Incidence of abnormality was 20 to 30% at 28 and 31°C, 48% at 34°C, and 77% at 37°C. The 8-arm stage was reached after 4 d at 28°C, 3 d at 31°C and 2 d at 34°C. Larvae displayed decreasing body length and arm length with increasing temperature. Larvae at 31°C have relatively long arms, as a result of a decrease in body length, not because of increased arm length. Incidence of metamorphosis was 43.9±1.7% (mean/plusmn;SD) at 28°C, 24.5±1.9% at 31°C, and 5.3% at 34°C. The size of metamorphosed juveniles was significantly larger at 28°C than at 31 and 34°C. Temperatures of 31°C negatively affect larvae and juveniles of the sand dollar.     

Evolution and reconstruction of settlement space in tourist islands: a case study of Dachangshan Island,Changhai County

Environment, Development and Sustainability - This study analyzes the evolution of the land use structure, demographic reconstruction, and social reconstruction of Dachangshan Island, Changhai...     

Study on cooperative strategies of rural water environment governance PPP project between companies and farmers from the perspective of evolutionary game

Environment, Development and Sustainability - The PPP mode of rural water environment governance was conducive to attracting social capital for giving full play to the decisive role of the market...     

羽序灯心草作为酸性矿山废弃地先锋植物潜力

生态复垦是当前世界各国酸性矿山废弃地修复的主要方法.通过研究云南来利山锡矿区废弃地土壤pH值、肥力特征及重金属含量,以及矿区生长的羽序灯心草形态特征和植株体内重金属的分布特征,分析植株耐酸性、对废弃地土壤肥力的适应性及对Zn和Cu等重金属污染的耐性,探讨其作为酸性矿山废弃地先锋植物的潜力.结果表明,研究区域根际土壤pH值均值范围为3.46～4.01,呈酸性;土壤中有机质、全钾、全磷和速效磷含量分别为10.28～25.75g·kg~(-1)、 8.84～9.32g·kg~(-1)、 0.56～0.63g·kg~(-1)和1.82～5.72mg·kg~(-1),处于较低水平;土壤中Zn、Cu和Fe含量均值范围分别为54.93～114.49、 92.53～127.59和47 133.60～112 259.63 mg·kg~(-1),其中重金属Cu含量超出风险筛选值1.85～2.55倍;研究区域羽序灯心草株高均值范围为43.77～55.42 cm,对照组植株高度为51.38～57.66 cm,无显著差异,表明羽序灯心草具有耐酸性及对重金属污染具有耐性.进一步分析对重金属Cu和Zn的富集能力和转移特征,发现对Cu和Zn都具有富集能力,且对Zn具有运转能力,具有一定的富集吸收潜力.株高与根际土壤中速效磷的含量显著相关,后期羽序灯心草作为先锋植物在矿山废弃地进行种植时,可针对性地补充含速效磷的肥料改善土壤肥力条件.综合分析结果表明,羽序灯心草作为先锋植物修复酸性矿山废弃地具有巨大潜力.     

中国菌糠露天焚烧污染物排放时空分布特征

基于我国2000~2017年食用菌年产量数据,采用排放因子法估算了菌糠露天焚烧的污染物排放量,利用Mann-Kendall法和聚类分析法分析了排放量的时空分布特征,使用回归分析法预测了污染物的排放趋势.结果表明：（1）2000~2017年全国菌糠露天焚烧污染物排放量持续上升,PM_2.5、CO₂、CO、CH₄、NMVOCs、PAHs、NO_x、SO₂累积排放量分别为1.40×10⁶,3.48×10⁸,1.99×10⁷,8.43×10⁵,2.08×10⁶,3.00×10⁴,6.34×10⁵,8.29×10⁴t;（2）污染物排放量较高的省区包括山东、黑龙江、浙江、湖南、江苏、福建和河南,排放量较低的省区包括贵州、宁夏、天津、北京、新疆、重庆、甘肃;（3）预计2021年菌糠焚烧污染物总排放量高达4.25×10⁷t,其对生物质焚烧污染物总排放量的贡献率约为19.82%.我国菌糠露天焚烧污染物排放规模较大,应予以重点关注.