The degradation of the algerian environment through economic and social ‘development’ in the 1980s

Concern for the better management of environmental resources grew during the 1980s. While this concern encompassed the misuse of the Third World's resources, those nations' governments and their peoples showed less awareness of the environmental damage being done in their quest for development. Environmental degradation has reached serious proportions in Algeria where oil wealth has masked failings of agricultural production and, together with industrialization, has provided a ‘veneer’ of economic development. The vulnerability of Algeria's natural environment and the fragility of its ecosystems have been stressed by Cǒte (1983). Once cleared, Algeria's woodlands and forests are slow to re-establish and surface deposits are easily erodable. Soils were largely formed under past climatic conditions, and so cannot be restored naturally by present pedogenetic processes. Such an environment is difficult and delicate to exploit to any high degree of agricultural intensification and is under increasing demographic pressure. Culturally and organizationally the agricultural system is far from ideal if agriculture is to be sustained. Often in Algeria the highest rainfall falls on the steeper slopes while the gentler slopes receive insufficient for agriculture. Only 500 000 hectares out of Northern Algeria's 38–40 million hectares receive more than 600 mm of rainfall and have slopes of less than three per cent (Cǒte, 1983). As much as 20 million hectares of Northern Algeria were identified by Dregne (1983) as … ‘vulnerable to desertification’ with large areas falling into his ‘severe’ risk category. This study seeks to demonstrate the dimensions of environmental degradation through observations and the monitoring (during the 1980s) of Algeria's media: largely newspaper and television reports. Particular emphasis is placed on the growing environmental ‘crisis’ since 1988. It should be stressed that the Algerian Government uses a controlled media to disseminate official information. Misuse and overuse of environmental resources have combined with inadequate government economic policies and a neglect of ecological issues to cause the ‘crisis’.     

沙化草地土壤有机碳及碳库管理指数的分异特征研究

本研究以宁夏盐池县潜在沙化草地(PD)、轻度沙化草地(LD)、中度沙化草地(MD)和重度沙化草地(SD)为对象,研究了不同沙化程度草地土壤有机碳(SOC)及其在不同粒径团聚体中的分布、活性有机碳组分和碳库指数在0～40 cm土层的变化,以探讨宁夏干旱风沙区沙化草地土壤有机碳及其碳库分配特征。结果表明：沙化导致草地SOC含量、储量及各粒级团聚体SOC含量显著降低,与PD相比,LD,MD和SD均降低40%以上。随草地沙化程度加剧,土壤易氧化有机碳(EOC)含量总体呈下降趋势,由PD的0.46～0.68 g·kg^-1降至SD的0.34～0.47 g·kg^-1,微生物量碳(MBC)含量在不同沙化程度草地之间差异不显著。伴随着草地沙化,EOC和MBC占SOC的比例逐渐升高,而碳库管理指数逐渐降低。由此,草地沙化可能会通过改变土壤有机碳活性而影响荒漠草原土壤碳库稳定性及草地生态环境质量。     

我国石漠化地区生态移民与人口控制的探讨

分析了石漠化地区的人口现状与特征;指出人口压力是石漠化形成的主要因素;提出解除和减轻石漠化地区人口压力的主要措施为控制人口和生态移民.     

半干旱沙地深栽造林钻孔机的性能试验与研究

深栽造林是解决半干旱沙地造林成活率和保存率最有效的方法之一，深栽造林钻孔机是用于深栽造林最为有效的设备。通过对设计制造的深栽造林钻孔机在实地－科尔沁沙地进行的钻孔阻力矩与钻头转速、进给速度不同造林地不同土壤硬度之间的关系等的性能试验表明：该机在科尔沁半干旱沙地进行造林作业、在钻头转速为360－400r/min和进给速度为0．047m/s时具有最佳工作状况和最大钻孔造林效率。在科尔沁沙地的土壤硬度条件下，用于深栽造林钻孔机的钻孔直径为90mm时最大的钻孔阻力矩为53Nm，而该机所能提供的钻孔力矩完全满足这一要求，并具有足够的扭矩储备。     

黄河故道区域土地沙漠化程度的景观尺度评价

黄淮海平原土地沙漠化扩展形势十分严峻,然而人们对它的发生、发展和存在潜在威胁的认识却远远落后于西北内陆和内蒙古高原沙漠区,这是防治该区沙漠化扩展、蔓延的最大障碍。黄淮海平原上的沙漠化以黄河故道和滦河下游冲积平原最为显著。作者以黄河故道典型区域山东聊城市为例,对该区的荒漠化程度进行景观尺度的评价。     

川西北草地沙漠化现状与防治对策研究

川西北高原草地沙漠化主要由气候、地质地貌、鼠兔虫害、过度放牧及不合理开发利用等方面因素综合影响造成。草地沙漠化不仅影响牧区生产生活与经济发展,而且还威胁到长江和黄河流域的社会经济可持续发展。为此,须采取部门配合、综合监测、林草结合、防止鼠兔危害、围栏防踏和生态性开发等综合措施加以防治。     

中国西部沙漠化与沙尘风暴问题探讨

我国西部地表植被向恶性循环方向发展，土地沙漠化面积迅速增长，沙尘风暴日趋频繁。分析中国西部沙漠化和沙尘风暴存在的主要问题，进一步探讨沙漠化和沙尘风暴形成的原因和对国民经济发展所造成的危害，因地制宜提出了相应的治理对策     

风蚀沙化对草原植被生物多样性的影响——以呼伦贝尔草原为例

通过对呼伦贝尔草地沙化过程中不同演替阶段植被物种组成和生物多样性研究,结果表明:草地沙化,灌丛化明显,群落结构趋干简单化;群落α多样性急剧下降,其中物种丰富度、多样性、均匀性,严重沙化草地分别比潜在沙化草地减少59.4%、54.0%和31.4%,而生态优势度增加44.9%,说明草地沙化后,群落物种数减少,优势种更加突出...     

关于水土保持专业课程体系设置的问卷调查

 课程体系的建立是水土保持与荒漠化防治特色专业建设的核心。通过座谈、问卷等调查形式,对水土保持与荒漠化防治专业本科培养方向、课程设置、学时安排、实践内容及学生实际能力等方面进行调查研究。结果表明：西北农林科技大学水土保持与荒漠化防治专业本科课程设置较合理,基本能满足社会实践需要,学生基础知识较扎实,但实际工作适应能力还有待提高;根据调查意见构建的新的课程体系,压缩了6门课程,增加了主要课程学时设置,可以更好地满足社会实践需要。     

旱胁迫条件下3树种幼苗光合特性比较研究

模拟石漠化山区土壤水分变化特征对滇楸、任豆和银荆当年实生幼苗的光合特性以及生理生态适应机制进行对比研究。研究结果表明,在CK,T1,T2,T34个不同处理组,3树种幼苗的净光合速率Pn、蒸腾速率Tr、表观光能利用效率LUE和表观CO2利用效率CUE的平均值均呈显著差异,其平均值的大小顺序为：银荆〉任豆〉滇楸,且各指标随着土壤含水量的减少而降低。在CK组,3树种幼苗的水分利用效率WUE的平均值均无显著差异,但在T2组银荆幼苗WUE显著高于任豆和滇楸。在4个不同处理组内,滇楸幼苗的气孔导度Gs显著高于任豆和银荆幼苗。