内蒙古梭梭荒漠草地资源及其保护利用

在简述梭梭荒漠地理分布的基础上,着重阐述了内蒙古梭梭荒漠植物区系特征,植物学特征,生态环境和生物学特性,经济价值,内蒙古梭梭荒漠草地资源在全国和内蒙古天然草地及荒漠草地中的地位、现状、重点保护及合理利用。     

Physio-ecological response of Haloxylon persicum photosynthetic shoots to drought stress

This paper studied the seasonal characteristics to resist the drought stress of Haloxylon persicum Bge. Ex Boiss. et Buhse photosynthetic shoots at habitat. The results showed that the predominant drought resistance factors were varied at the different stage from growth to development. In the blooming season (from May 31 to June 29), endogenous ABA contents were rare; stomatal conductance and photosynthesis intensity were the highest at the whole stage from growth to development; soluble sugars contents had a decreasing trend and proline contents increased a little that made proline become the predominant factor to resist the drought under this light water stress. In the hot summer (from June 29 to July 26), ABA contents accumulated rapidly; stomatal conductance dropped to the lowest level of the growth and development; chlorophyll was also decomposed; both soluble sugars and proline contents showed the trend of quickly accumulating, but the former was faster than the latter. It was due to stomatal limitation and osmotic organic molecules accumulation that would affect the photosynthetic shoots to resist severe drought stress. At the late period of the development (from Aug 9 to Aug 22), ABA rapidly accumulated, its contents got to the highest level of whole life-span; stomatal conductance increased a little; proline and soluble sugars contents changed little at high level; while the ratios of ABA to CTK content and ABA to IAA content got up obviously, the effect to resist drought stress on high content ABA was inhibited by endogenous plant hormone CTK and IAA, then the continuing accumulation of proline and soluble sugars would be prevented. Osmosis of organic molecules was the most important factor to adjust leaves to severe water stress at this period. __________ Translated from Scientia Silvae Sinicae, 2005, 41(5) [译自, 林业科学 2005, 41(5)]     

不同结皮破坏对退化梭梭林地土壤水分及梭梭生长的影响

在甘肃民勤对20世纪60年代建植的人工梭梭林进行植被恢复研究试验,结果表明,结皮破坏可以增加林地水分入渗深度,降低地表径流,提高土壤含水率,对退化梭梭有恢复作用。3种改造措施中,土壤水分储存效果以处理Ⅰ和处理Ⅱ较好;结皮的存在易造成坡面径流,而结皮破坏则阻止了坡面径流的产生,并增加了土壤水分入渗;退化梭梭恢复以处理Ⅰ和处理Ⅱ梭梭的枝条成活率最大,达到6.67%,新枝枝数、枝长、基部粗度以处理Ⅰ占优势;新结皮形成方面,处理Ⅰ不易形成新结皮,处理Ⅰ,处理Ⅱ和处理Ⅲ形成的新结皮厚度分别为0.22 cm,0.27 cm和0.38 cm。     

乌拉特后旗努登梭梭林自然保护区资源现状及经营管理建议

天然林保护工程已列入国民经济重要议事日程 ,强化保护区建设是实施天然林保护工程的重要内容。文章通过分析保护区资源利用现状 ,提出保护区经营管理意见 ,仅供参考。     

梭梭种子性状和繁殖力的遗传变异与评价

通过对梭梭6个种源的种子性状和繁殖力的研究,结果表明:(1)不同种源间种子性状和繁殖力存在显著差异,其质量指标差异大于形态指标,即单株种子重差异最大,千粒重次之,果翅长度最小;成活率的差异性明显大于发芽率。(2)各种源区间的种子性状和繁殖力之间的遗传差异为极显著水平,环境差异为显著水平,梭梭种子质量主要受遗传基因控制,而种子繁殖力则受遗传基因和环境因素及土壤等多重因素控制。(3)种子各性状与成活率均呈正相关。除果翅长度与成活率相关不密切外,其它性状之间均为极显著相关。(4)在种子果翅长度、千粒重、单株种子重、发芽率和成活率等5个指标中,变异程度最高的是单株种子重,最低者为成活率;各种源区种子各性状具有较高的重复力(0.8580~0.9737),受强度遗传基因控制,通过种源选择可望获得良好效果;通过对发芽率指标选择,可比直接从成活率选择提高2.40%~24.86%(10%的选择率)的遗传进度;经综合选优评价,内蒙磴口种源的种子性状和繁殖力最好,青海次之,其次为甘肃和内蒙乌后旗,内蒙额旗和新疆最差。     

梭梭抗旱性相关研究现状及对今后研究的建议

梭梭是我国西北地区重要的沙生植物。文中综述了其形态解剖特征、光合特征、水分、保护酶和渗透调节等抗性生理方面的研究现状。建议开展梭梭无性繁殖、生理生化基础理论、常规杂交育种和基因工程育种、抗旱分子机制等方面的研究, 为充分挖掘利用梭梭所特有的优良性状及其基因打下基础。     

抗旱造林粉在民勤干旱沙区梭梭造林上的应用

2010年通过抗旱造林粉在民勤干旱沙区沙丘"双眉式"麦草方格沙障上进行梭梭裸根苗浸根法造林应用试验,结果表明:抗旱造林粉在民勤干旱沙区能提高造林成活率,可以提高植物体自身抗性,控制水分丧失,维持植物体水分平衡,延缓植物生命周期,抑制林木生长状态,降低造林成本,促进梭梭生长发育.因此,抗旱造林粉在干旱、半干旱地区应用已成...     

石羊河下游干旱荒漠区梭梭林害虫种类及防治对策

通过对石羊河下游干旱荒漠区梭梭人工林害虫的调查,结果表明：梭梭人工林发生的害虫有24种,其中：叶梢害虫有17种,枝干害虫有7种;害虫种类数量分布次序为：直翅目＞鞘翅目＞同翅目＞鳞翅目＞半翅目,其中梭梭绵蚧造成梭梭死亡率较高,是一种新发生的危险性较高的害虫.针对该区域梭梭林害虫发生现状,提出了防治对策.     

民勤绿洲外围人工梭梭林种子库研究

通过对石羊河下游民勤绿洲外围人工梭梭林土壤种子库特征调查分析,结果表明：种子分布在时间上,4月份158．0粒／m2,8月份86．6粒／m2,8月份的种子量只是4月份的54．8％;在种子水平分布上,种子分布规律是沙丘背风坡〉丘间滩地〉沙丘迎风坡〉沙滩地;在垂直分布上,0—2cm土层中分布植物种子总量的87．8％,2—5cm土层中分布植物种子总量的11．6％,5cm以下的土层中只分布植物种子总量的0．06％。梭梭林土壤种子库平均储种量为122．3粒／m2,其中,梭梭种子的平均储量为28．9粒／m2,最小储量为1．6粒／m2,最大储种量为56．1粒/m2。梭梭林土壤种子库中约80％的梭梭完整种子的生活力极低,但林中仍有梭梭幼苗分布,说明土壤种子库的梭梭种子具有一定的萌发能力。梭梭林土壤种子库储量为中等水平,并具有一定的萌发能力,能够为开展封沙育林草提供基本条件。     

Causes of seedling mortality in desert for the small xeric tree Haloxylon ammodendron

The destroyed vegetation dominated by Haloxylon ammodendron (C. A. Mey.) Bunge resulted in more moving sand dunes in Gurbantunggut Desert of Northwest China. Natural vegetation restoration is difficult due to high seedling mortality of H. ammodendron, which has unclear causes. Two independent field experiments on relationships between key environmental factors and survival of H. ammodendron seedlings were carried out in Gurbantunggut in the spring of 2008 and the summer of 2009. The spring experiment suggested that the number of ephemeral plants was significantly increased with more precipitation, and they competed for water and reduced survival of H. ammodendron seedlings. The highest H. ammodendron seedling survival was for treatment with least precipitation, though the differences were not significant among treatments. The summer experiment showed that variation in seedling mortality was well explained by water content in 0–20 cm layer. It is concluded that in spring, competition for soil water from ephemeral plants is the primary determinant of seedling survival. In summer, without competition of ephemeral plants, seedling survival was mainly determined by drought, which can be either drought of the soil or dryness of the air: when the soil moisture content at upper layer was <1.25%, dryness of the air governed the seedling mortality, otherwise the dryness of the soil governed the seedling mortality.