阿拉善盟处于内蒙古最西部的荒漠地区,长期以来除干旱性灾害外,还常受到虫害的侵袭,虫害是造成草原沙化、退化的重要因素之一.为了弄清阿拉善盟草原昆虫种类及其在阿盟生态系统的地位和意义,本文主要通过整理探讨阿拉善盟昆虫的种类组成,作为阿拉善盟生态系统研究的一个组成部分,以供开发、利用、保护资源和其他方面的参考.

For decades, arid desert ecosystems in northwest China, covering one-fourth the country’s land surface, have experienced a rapid decline in plant species diversity, productivity and soil carbon stock owing to degradation by overgrazing. In this study, plant community composition, diversity and productivity, as well as soil carbon (C) and nitrogen (N) stocks, were monitored over 26 years from 1981 to 2006 in a severely degraded Haloxylon ammodendron-dominated shrubland where livestock densities were reduced from 4–5 to 1–2 dry sheep equivalent ha-1. The objective was to assess long-term grazing effects on vegetation and soil C and N accumulation dynamics. Results showed that the reduction of grazing pressure significantly increased vegetation cover, plant diversity and productivity, resulting primarily from an increase in livestock-preferred species. Controlled grazing also led to marked increases in soil C and N stocks in the top 30 cm of soil. This increase was strongly associated with increased plant species richness, vegetation cover and biomass production. Averaged over 26 years, soil C and N accumulated at rates of 89.9 g C and 8.4 g N m-2 year-1, respectively, but rates of C and N accumulation varied greatly at different time periods. The greatest species regeneration occurred in the first 8 years, but the largest C and N accumulation took place during years 9–18, with a time-lag in response to changes in vegetation. Our results provide insights into the long-term recovery patterns of different ecosystem components from the influence of prolonged overgrazing disturbance that cannot be inferred from a short-term study. The findings are important for assessing the resilience of these livestock-disturbed desert ecosystems and developing a more effective strategy for the management of this important biome from a long-term perspective.

通过对内蒙古自治区阿拉善左旗的植被样方调查,研究干旱荒漠地区植物群落物种多样性的梯度变化和空间分布特征。通过对样方数据的群落生活型构成、物种丰富度、α多样性、β多样性分析,结合CCA排序和地统计方法,结果表明:（1）在该区域植物物种的α多样性和β多样性均起伏较大。（2）草本植物的丰富度由西向东呈增高趋势,而灌木的丰富度则呈降低趋势;随纬度的增加,草本植物丰富度呈现下降趋势,而灌木丰富度则显现出上升趋势。但是,38°～39.2°N之间出现了一个灌木和草本物种丰富度都相对比较低的异常区域。（3）α多样性与经度正相关,但与纬度存在负相关关系。β多样性显示,随着经度的增加,自西向东样方间物种构成的相似性降低,物种替代速率升高。随着纬度的增加,群落组成呈现逐渐单一化的趋势。（4）Shannon-Wiener指数和Shimpson指数的C0/（C0+C1）都在0.25～0.75之间,α多样性为中等空间相关性。CCA分析的结果表明,地理因素对于物种多样性有显著的影响,而且经度的影响大于海拔的影响。研究阿拉善左旗荒漠区植物物种多样性的梯度变化和空间分布特征,为认识和保护荒漠地区生物多样性资源提供了理论依据和实践基础。

“生态安全”是国家安全的重要组成部分,是维系一个国家经济社会可持续发展的基础。阿拉善位于内蒙古自治区最西部,总面积27万km2。辽阔的阿拉善植被是阻挡西北风沙入侵我国北方地区的重要天然屏障,长期以来,由于气候和人为影响,阿拉善植被遭到严重破坏。草地“三化”面积达到58 630.53km2,占全盟可利用草场面积的57.1%,生产力急剧下降。

近年来阿拉善荒漠植被害虫连年发生,不仅给畜牧业生产造成很大损失,而且使生态环境日趋恶化。本文根据近年来的调查和防治,对阿拉善草地几种主要害虫的生态环境、生物学特性、发生危害特点,进行了研究。目前阿拉善草地大面积发生的害虫主要有僧夜蛾白刺叶甲、巨膜长蝽、柽柳条叶甲和胡扬天幕毛虫,每年发生面积达400多万km2,严重发生区,造成荒漠植被连片死亡。为了有效的保护草地生态,通过研究,对不同害虫的治理提出了四点防治对策。

本文指示生态自我修复是指对因人类活动而受损的生态系统,通过直接社会控制手段,依靠生态环境演替自我修复,从科学和学术角度积极开展对生态自我修复的研究,大力开展生态自我修复工作,走人与自然的协调发展和西北经济社会的可持续发展意义重大.

Ammopiptanthus mongolicus, which is an endemic and endangered species in China listed in the Red Data book, is a type of evergreen broad-leaved shrub in dry deserts of Asia. A. mongolicus is distributed mainly in the Alashan region of Inner Mongolia, but, for unknown reasons, the range of the population has been declining. We studied the distribution patterns and characteristics of A. mongolicus as a preliminary step in understanding the dynamic changes of the population and community and the factors causing the population decline. In Alashan Zuoqi, 36 quadrats (20 m×20 m) and 150 grids (5 m×5 m) were set up at 3 sites (Dongqingliang, Sumutu and Luanjingtan). There were at least 12 quadrats and 50 grids in every plot. The distribution patterns, stand density characteristics, morphological characteristics, and dynamic changes of the A. mongolicus populations at the 3 sites were compared. The results showed that A. mongolicus populations formed different distribution patterns under environmental conditions. The population was distributed evenly on flowing-sand or semi-fixed windy sand but was distributed contagiously on ancient riverbeds or stone slopes caused by seasonal floods. Individuals of A. mongolicus had different morphologies based on the population density and environment characteristics. On flowing-sand, individuals had shorter heights and smaller diameters but the relationship between height and width was not significant (R_1=0.096). There was a negative relationship between population density and the height and diameter of individuals in the population on flowing-sand (R_2=-0.214, R_3=-0.339). Individuals growing on semi-fixed windy sand and stone slopes had significantly greater heights and diameters, but there was no significant relationship between population density, and the diameter and the height. On stone slopes, the relationships between individual diameters and the heights were not significant (R_1 = 0.886), and there were no significant relationships between population density and height and width (R_2 = 0.089, R_3= 0.055). The densities of A. mongolicus populations were the highest at the flowing-sand site and the lowest at the stone slope population where seasonal floods occurred. Populations of A. mongolicus had different age structures at the different sites. At the flowing-sand site, there were even numbers of mid- to old-aged individuals but few young individuals, indicating that the population was senescing. At the semi-fixed windy sand and stone slope sites, there were also very few young individuals, and the number of individuals in the different age classes was distributed very unevenly. All three populations had limited the regeneration questioning the long-term viability of these populations.

On the base of summary of past and present experience and achievements of desertification control, it was believed that the desertification in Inner Mongolia could be controlled by strengthening international and domestic close cooperation, establishing scientific development viewpoint, adjusting industrial structure, rehabilitating forest and vegetation, relying laws, engineering and science.

根据对腾格里沙漠周边地区的调查研究及科研成果,提出了只要很好地实施政策法律、科学技术、工程项目、产业结构调整和资金筹集等措施,该地区的生态环境综合治理目标有望能够实现.

Investigations on the soil seed banks of different grassland types of Alashan arid desert region in Inner Mongolia showed that when the altitudes of sampling plots increased from 1,370 m to 1,750 m, the soil seed densities of natural grasslands decreased from 326 grain.m-2 to 76 grain.m-2. At the altitude of 1,100 m, the soil seed density was 56 grain.m-2 in typical desert plot, but only 8 grain.m-2 in the sand dune plot. After the vegetation was restored with Artemisa sphaerocephala on sand dune, its soil seed density increased obviously, almost as 17-29 times as sand dune's. In this study, 31 seeds m-2 were sampled, which belonged to 11 families. Among them, annual plants accounted for 77%, 100% and 70%, perennial plants accounted for 21%, 0 and 16%, and semi-shrubs accounted for 2%, 0 and 14%, respectively for natural grassland, sand dune and sown grassland. Shrub seeds were not found in all the soil seed bank plots. When the altitudes of sampling plots increased from 1,100 m to 1,750 m, the species richness (Margalet index) of soil seed banks of natural grasslands increased from 1.49 to 2.77, and the species diversity (Shannon-Winner index) increased from 0.697 to 0.917.

1998年8～9月和1999年8～9月在内蒙古阿拉善地区对啮齿类进行了调查,捕到内蒙古兽类两个新记录种:间颅鼠兔(Ochotona cansus)和肥尾心颅跳鼠(Salpingotus crassicauda),经鉴定在国内属新的分布区.

Desert shrub land with Reaumuria soongrica as the dominant or edificator species is one of the main grassland types in the northwest of China. It plays an important role in environmental protection. Affects of different over grazing intensities and enclosure on vegetation succession of Reaumuria soongrica + Cliestogenes songorica grassland at Alxa region, Inner Mongolia, were reported in this study. The total vegetation coverage had reduced to 8% from 12% during the last 6 years. As grassland degraded (light, medium and heavy degradation), the R. soongrica shrubs were gradually decreased, it s coverage at medium and heavy degraded regions were 74% and 84% of that in the light degraded region respectively, where the cover was 7.5% (P0.05). Accordingly, the herbs with lower yield or poorer feeding value were increased. The increasing of C. songorica and Peganum nigellastrum could be the indicators for the medium and heavy degradation grasslands, respectively. Significant effects of vegetation restoration were obtained from short time fencing without grazing. One growing season after fencing, the average vegetation cover increased by 1.7% and forage yield increased by 218.8%, compared to that of open grazed, and seed yield of R. soongrica was 371 times of grazed paddock. However, during the fenced period the relative restoration rates of the dominant species R. soongrica were increasingly reduced (P0.05) both in coverage and yield as the grassland degradation become heavier. And restoration rate was zero at the heavy degraded paddock. Therefore, the fenced non-grazing technique is an effective approach to restore and protect the R. soongrica desert grassland, however, the fencing work need start as early as possible, otherwise, the restoration of R. soongrica vegetation will be either very slow or impossible.

Relationships of soil water content and plant growth in %A rtemisia sphaerocephala\% air-sown grassland were studied in southeastern edge of Tengger desert. The results showed that when vegetation densities was 5\^1～9 plant\5m -2, soil water contents were only 0\^55%～0\^70% in 0～100 cm laye r severely insufficient to need and plant mortality rates were as high as 55%～76\^ 7%; When vegetation density was 1\^9 plant\5m -2, soil water content were 0 \^65%～1\^01% and plant mortality rate was 21\^1%; However, when vegetation dens i ty was 1\^25 plant\5m -2, soil water contents were 0\^79%～1\^48%, no plant died, individual plant was growing better than those in high density field, and self-multiplied seedlings were growing under this condition. Therefore, the opt imal density of \%Artemisia sphaerocephala\% was about 1\^0 plant\5m -2 in this area. The study also indicated that soil granule constituent and microbioti c soil-crust depth were affected by vegetation density greatly. Coarse sand con tents were respectively 37\^0%, 25\^8% and 16\^3% in bare desert, middle vegetat ion density and high vegetation density, whereas the correspondent thick of crus ts were 0, 1\^1～1\^2 and 1\^4～1\^7 cm. By contrast, soil water content was 1\^ 3%～2\^48% in bare desert.

在飞播区根据牲畜对沙拐枣啃食程度的不同,采用人工模拟放牧方法对牲畜啃食的绿色部分设置了10%、30%、50%、70%、90%、对照6种不同啃食强度处理,以探讨啃食强度对沙拐枣生长的影响.试验结果表明,30%啃食强度的生物量比90%的高121.37%,比对照高34.85%.沙拐枣的啃食强度在30%～50%时生物量最高,完全不利用或过度利用都会影响其正常生长.

根据飞播区牲畜对白沙蒿啃食程度的不同,采用人工模拟放牧方法对牲畜啃食的嫩枝及绿色部分设置了10%、30%、50%、70%、90%、对照6种不同啃食强度的处理,探讨啃食强度对白沙蒿生长的影响.试验结果表明,白沙蒿放牧利用强度控制在30%以下,有利于白沙蒿的生长,否则会影响其正常生长.

对阿拉善草地几种主要害虫的生态环境、生物学特性、发生为害特点进行了研究.阿拉善草原大面积发生的害虫主要有白刺夜蛾、白刺粗角叶甲、巨膜长蝽、柽柳条叶甲和胡杨天幕毛虫,每年发生面积达400万hm2,严重发生区,造成荒漠植被连片死亡.为有效保护草地生态,研究并提出了对害虫治理的对策.

The ecological feature, distribution and their harmfulness of some rodents in Alashan desert were investigated. The results indicated that rodents started frequent action in April, which were harmful most of desert shrub species. The holes density reached 46% in severe rodent happened area. Rodent action was one of major factors which caused desert grassland deterioration and desertation. April to May were suitable season to control rodents. Poison bait, smoke and eco control were effective ways to control them.