公路岩质边坡植被修复及生态防护景观营造研究

为应对四川省自贡市公路建设中面临的地形复杂、地质破碎、生态敏感和气候极端等工程难题,提升城市主干线大型绿化带的生态景观品质,采用植被生态修复防护技术,构建土壤生境、植被群落和物质循环3个系统。通过物理防护、抗蚀防护和植被生态修复防护3种措施,实现边坡的稳定性和生态环境的改善。研究结果表明,该技术能有效恢复植被生产力,保持名贵乔木的养分,并促进其快速生长,提高公路的安全性和美观度。

三系统耦合植被生态修复技术在乌拉山北麓铁矿区生态环境修复中的应用

矿产资源开发利用在国民经济建设中的地位日益重要,内蒙古自治区巴彦淖尔市乌拉特前旗乌拉山北麓铁矿区经过几十年露天开采,不但破坏了当地土地资源,而且破坏地貌景观,损害生态环境。对乌拉山北麓铁矿区矿山边坡采用三系统耦合植被生态修复技术,修复效果良好,取得显著的生态、经济和社会效益。本文详细阐述了三系统耦合植被生态修复技术设计方案和施工工艺,为矿山创面生态修复提供了可借鉴经验。

Effects of Acetochlor and Methamidophos on Fungal Communities in Black Soils

Using plate counting and ergosterol assay, single and joint effects of acetochlor and methamidophos on the dynamicsof soil fungal population and total fungal biomass in the black soil zone of Northeast China were investigated. The resultsdemonstrated that acetochlor at high concentration levels (150 and 250 mg kg-1) had an acute and mostly chronic toxicityon both the soil fungal population and total fungal biomass, but at a low concentration (50 mg kg-1) generally had astimulating effect that was stronger with total fungal biomass than with the soil fungal population. Methamidophos ata high concentration level (250 mg kg-1) alone and almost all of its combinations with various dosages of acetochlorincreased the soil fungal population, whereas at most sampling dates with 250 mg methamidophos kg-1 soil, total fungalbiomass increased, but in combination with acetochlor it was decreased in the early period of incubation and then increased28 days after incubation. Thus, through measuring the number of colony forming unit of the soil fungal population alongwith the total fungal biomass, a better understanding on effects of agrochemicals on soil fungi could be made.

STATUS, CAUSES AND COMBATING SUGGESTIONS OF SANDY DESERTIFICATION IN QINGHAI-TIBET PLATEAU

The Qinghai-Tibet Plateau is one of the major sandy desertification regions of China. Based on the recent investigation on sandy desertification, this paper analyses the status such as the type, area, distribution and damage of sandy land desertification in the plateau. Through the analysis on the factors affecting sandy desertification in the region’s natural and socio-economic systems as well as the processes and their interrelations, it can be concluded that sandy desertification in the Qinghai-Tibet Plateau resulted from the combined actions of normal natural sand drift processes, natural sandy desertification processes caused by climatic changes and man-made sandy desertification caused by improper human activities. In addition, it also predicts the possible developmental trend including the increase in desertification area and the enhancement in desertification developmental degree with the exacerbation of the complex processes, and finally puts forward some strategic suggestions to combat sandy desertification in the coming years.

Populus euphratica, a Tolerant Model but Endangered Arborescent Species

Populus euphratica is a most tolerant arborescent species to abiotic stress. It can adapt to extreme conditions, ranging from flood to atmosphere extremely dry, hot from + 54 ℃ to - 45 ℃, and from normal soil to the soil with very high salt concentration ( to 2 ～5%) although being a non-halophyte. However, the natural stands of P. euphratica have been shrinking tremendously for the past decades and some populations are facing the fate of extinction. The preservation of existing resources should be carried out as a burning issue. In parallel, P. euphratica could be taken as a model plant to explore the molecular mechanism of abiotic-stress tolerance and to exploit its tolerant genes due to its smaller genome and easy molecular manipulation. The measures for preservation, germ-plasma exploitation, tolerance mechanism exploration and resource utilization were also discussed in this paper.

Causal Analyses of Desertification in Semi-arid Agro-pastoral Ecotone of China: A Case Study in Ejin Holo County, Inner Mongolia

Desertification is one of serious problems menacing the global environment and food security, andthe determination of causes of desertification is the basic issue for the coordinate actions to fight against it. InChina, the most serious desertification occurs in agro-pastoral transition zone. Considering the consistencyof socio-economic factors, Ejin Holo county in Inner Mongolia was selected out to analyze the desertificationcauses in this paper. Results showed that erratically climatic factors provided fragile background and drivingforces for desertification processes, and sand-covered surface and its underlying materials and specificgeomorphologic features have a great contribution to desertification processes as well. Socio-economicdevelopment, especially the traditional land management, the landuse patterns and the increase of livestockand human population were the root causes for desertification occurrence and expansion.