填埋场甲烷氧化传输与释放预测模型研究进展

基于目前填埋场甲烷氧化与释放过程的影响因素研究,综合评述了填埋场甲烷氧化、传输与释放模型的研究进展,分析了导致填埋场甲烷释放预测模型准确性、可靠性差的主要原因;通过系统分析植被对填埋场甲烷传输与氧化过程的影响规律,揭示了植被传输机制在提高填埋场甲烷预测模型准确性方面的重要作用.     

Analysis of deforestation pattern in the Niger Delta region of Nigeria

This study examines deforestation in a part of the Niger Delta region of Nigeria between 1987 and 2013 using remote sensing data and geographic information systems. The results indicate an increasing rate of deforestation, an increasing rate of water body loss and a decreasing rate of exposed surface/settlement increase. The results also show that the rate at which cropland/secondary vegetation is increasing is above average while sandbar is increasing below average. The implications of these changes include environmental degradation resulting from loss of biodiversity and loss of forest goods and services. These losses can also affect the social and economic conditions of local people. The study recommends that policies and strategies targeted at slowing down the rate of forest loss and degradation should be pursued.     

Spatially explicit models of land abandonment in the Amazon

Given growing concerns about biodiversity loss and carbon emissions stemming from tropical deforestation, it is important to identify the factors associated with land abandonment as they might indicate areas that were deforested but are unsuitable for long-term cultivation. This article utilizes a high-resolution, Landsat-based data-set called TerraClass to relate land abandonment to precipitation, slope, farmgate price of beef, market access, soil quality, and land tenure characteristics in the Brazilian Amazon. The spatially explicit statistical models reveal that rates of land abandonment increase with higher rainfall and slope values, even when controlling for distance to roads, farmgate prices, type of settlement, and soil quality. Moreover, land adjacent to a major road is more likely to be consistently cultivated, but land near large rivers and far from highways is more likely to be abandoned. Land ownership type also influences the likelihood of land abandonment as settlements based on communal property rights have higher rates of land abandonment than settlements with private lots. These results suggest that policies aimed at occupying tropical forests such as the Amazon must consider these biophysical and socioeconomic factors in order to foster human development aligned with sustainability principles.     

生活垃圾填埋场填埋气中汞的分布特征

利用Tekran 2537A和Lumex RA-915汞分析仪分别对生活垃圾填埋场排气筒、填埋场内部的气态总汞变化规律进行了分析,结果表明,填埋场排气筒中气态总汞含量呈现明显的昼夜变化规律,白天高于夜间,并于午间达到峰值。气象条件对汞的释放过程有重要影响,光照强度与排气筒中气态总汞含量的相关性明显。受填埋场内部物理、化学、生物作用的影响,填埋场内部填埋气的汞浓度明显高于排气筒中填埋气的汞浓度。填埋场内部气态总汞变化规律为:植被覆盖区域明显低于无植被覆盖区域,表明有效的绿化措施对于控制填埋场汞污染具有重要意义。     

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The study focused on the so-called dark coniferous forest belt on the northern slope of Changbai Mountain, at an altitude of 1100 to 1700 m. Forty tree species, 50 shrub species and 165 herb species were recorded in a series of transects. The main impact factors on forest diversity and proposals for sustainable management of this diversity were studied using an altitude and area gradient pattern method. The results showed that the diversity of dark coniferous forest gradually decreased from lower to upper altitude; while the importance value of key species increased. The methodology used to assess attributes for conservation of dark coniferous forest diversity involved measurement of individual trees, number of species, age structure, stand structure, diameter at breast height (DBH), and cumulative wood storage. Different conservation strategies have been developed and are discussed for different parts of the forest.     

Traditional Ecological Knowledge and Practice for Edible Wild Plants: Biodiversity Use by the Rarámuri,in the Sirerra Tarahumara,Mexico

The Rarámuri who live in the Sierra Tarahumara of Chihuahua State, Mexico have developed local knowledge and harvesting strategies for edible wild plants that have the effect of conserving the biodiversity of their forest ecosystem. This paper presents the results of ethnobotanical research undertaken in the community of Basìhuare in the Sierra Tarahumara, to provide details on some practical aspects of the Raráamuri worldview regarding interconnections between people and their environment. This traditional philosophy forms the basis for the use of edible wild plants and the harvesting strategies practiced in Basìhuare, such as selective harvesting, environmental modification and domestication. These activities provide the opportunity for harvesters to monitor the landscape and the plant resources that occur on the land, as well as present a setting for the communication and exchange of traditional ecological knowledge. However, Rarámuri harvesting practices are under stress because of increased external pressures from commercial timber extraction and other development. We discuss the state of traditional ecological knowledge and its transmission in the context of development activities in the region. The key to sustainability in the Sierra Tarahumara may be the maintenance of traditional management practices for edible wild plants, and other nontimber forest products, that lead to the conservation of biodiversity by creating patchiness and renewing the plant cover on the land.     

基于气象和遥感数据的河南省干旱特征分析

干旱是一种常见的自然灾害,严重影响着我国的农业生产。论文分别采用标准化降水指数(SPI)和条件植被指数(VCI)对河南省干旱时空特征进行分析,并探讨了气象干旱和农业干旱的相关性。结果表明:近60 a河南省气象干旱频率呈现出轻微上升的趋势,夏秋两季气象干旱频率较高,农业干旱频率在秋冬两季较高,气象干旱和农业干旱频率在不同季节呈现出不同的空间分布特点。整体上看,农业干旱相对于气象干旱,存在一定程度的滞后:冬季最长,约为2个月,春季较长,约为1个月,而夏季最短,小于1个月;河南省SPI和VCI的相关性具有明显的时空分布特征:冬季和春季相关性较强,夏季次之,秋季最差;平原和盆地区等冬小麦/夏玉米种植区正相关性较强,在非耕地区有所减弱,而在信阳南部等水稻种植区正相关性差。     

盐城海滨湿地植被地上生物量遥感估算研究

以盐城湿地自然保护区核心区的ETM+图像数据和同期野外实测的31 个样方地上生物量干重、湿重数据为数据源,分析了15 个遥感信息变量与湿地植被地上生物量干重、湿重的相关关系,并选择在0.01 水平上显著相关的8 个遥感变量建立一元线性回归模型、一元曲线回归模型以及多元逐步回归模型,并对比得出最优模型,进而计算出整个研究区的地上生物量。研究得出：①与研究区湿地植被地上生物量干重和湿重相关性最大的都是ETM+4 波段,干重的相关系数为0.833,湿重的相关系数为0.796;②研究区植被地上生物量干重和湿重的遥感估算模型都是一元三次函数模型,且干重模型的拟合精度要优于湿重模型;③得到研究区地上生物量干重总重量为2.28×10⁸ kg,湿重总重量为6.10×10⁸ kg。     

PCR-DGGE研究沸石植生混凝土微生物群落结构

采用PCR-DGGE技术研究了滨水区和非滨水区沸石植生混凝土内部微生物群落结构,结果表明:沸石植生混凝土内部微生物多样性指数和物种丰度值均很高,滨水区和非滨水区植生混凝土内部微生物多样性指数与物种丰度总体持平,但是各部分微生物丰度差异明显.滨水区微生物丰度值根部5~10cm>根部10~15cm>沸石表面生物膜.非滨水区微生物丰度沸石表面生物膜>根部5~10cm>根部10~15cm.基因测序结果和系统发育树分析可知.滨水区和非滨水区以及沸石混凝土内各部分之间优势菌种各不相同,在滨水区,沸石表面微生物膜中优势菌种为丙酸杆菌、都柏林克罗诺杆菌和葡萄球菌属,根部5~10cm中优势菌种为黄杆菌和沙门氏菌属,根部10~15cm中优势菌种为慢生根瘤菌属;非滨水区,沸石表面微生物膜中优势菌种为芽孢杆菌和红假单胞菌属,根部5~10cm中优势菌种为沙门氏菌、微球菌亚目的Agromyces和酸杆菌属,根部10~15cm中优势菌种为沙门氏菌属.     

Report of A Survey of the State of the Environment in the Estonia,Latvia and Lithuania

In connection with the change in economic principles and disintegration of big industrial enterprises, the environmental pollution in Baltic States decreased considerably in 1991-1996. Although there are still many things waiting to be done, the improvement of the Baltic environmental situation during the years of independence gives us a cause to be optimistic.