沙漠地区GPS精度分析

介绍了GPS在沙漠地区资源调查、工程造林中地块测量的精度,选择已知地物作为测量对象,对测量误差及其精度进行分析计算,结果表明:GPS测量在沙漠地区资源调查、工程造林中林地测量精度不能完全满足林业中的应用要求,同时对GPS在实际应用中应注意的问题提出建议。     

阿尔金山北麓野骆驼生境植被调查研究

阿尔金山北麓是野生双峰驼的主要分布地区之一,在该地区野生双峰驼的生境内设立样线样方,对野生双峰驼生境内沙漠植被组成、地理区系和群落多样性等特征进行调查分析。结果表明,该地区的沙漠植物较为稀少,有9科17属17种植物,植物区系倾向于集中在少数大科和单种属内,优势科属的组成较少;该地区植物科的地理分布型有3种,属有5种地理分布型和2个变型,总体植物区系的温带性质较为明显,并呈现了与古地中海成分的相关性;该地区的植物群落物种组成稀少,结构单一,群落多样性指数较低,这与荒漠植物生境的严酷性有密切关系。     

新疆荒漠几种重要野生药用植物资源及其人工栽培

药用开发利用是目前野生植物资源利用的重要途径之一，许多中草药都直接取自野生植物。中国沙漠地区约有植物1700余种，其中被收入《中国沙漠地区药用植物》一书中的药用植物为356种，而人们正在开发利用以及未被认识的野生荒漠药用植物的种数则远远不止于此。中国科学院吐鲁番沙漠植物园所引种的400余种荒漠植物中具有药用价值或属于药用植物以及原料药物类植物的占80％以上。     

沙米生长特性调查

通过对沙米生长特性、种群动态及其对水分的影响等方面系统的调查,探讨流动沙丘上若留有片状枯萎的沙米,（翌年）沙米植株之间就不再生长新生沙米的可能原因。同时,利用先锋植物的这种生态适应机制,探讨了沙漠地区短命植物适应干旱环境的生长特性。     

库布齐沙漠七星湖酒店景观绿化工程苗木栽植技术及成活率浅析

论述了在库布齐沙漠腹地进行景观绿化工程所采取的栽植技术措施,并分析探讨了在沙漠地区影响苗木成活率的重要因素,表明在沙漠地区进行景观绿化工程必须充分掌握引入种树木生物学特性,结合当地自然条件制定适宜的栽植技术措施;确保正常季节栽植,避免反季节栽植;尽量做到苗木随起随栽,避免假植;合理搭配植物,确保整体景观效果。     

利用ENVI和ArcGis对乌兰布和沙漠白刺沙丘边缘提取

本文以乌兰布和沙漠的遥感影像中白刺沙丘为研究对象,利用ENVI和ArcGis软件对其进行地物边缘提取。通过对比提取后的白刺沙丘形状和外业调查数据,发现其吻合效果较好。又通过对其测量精度验证,检验其有较高的提取精度。通过利用ENVI和ArcGis提取乌兰布和沙漠遥感影像中白刺沙丘边缘的研究,目的是为利用遥感影像提取沙漠地区植被的调查提供参考和技术支持。     

塔克拉玛干沙漠腹地植物引种与适应性评价

在对塔克拉玛干(塔中)引种植物进行调查的基础上,对所引种的植物进行了适应性评价.并为沙漠公路防护林工程建设筛选了适宜的植物种.结果表明,塔中共引种植物274种(隶属于34科83属),现存149种,死亡86种,流失39种.引种植物中灌木、草本较多,乔木较少,藤本极少;灌木是较适宜种,引种成活率最高,乔木和草本相差不大;草本流失率最高,灌木次之,乔木最低.适宜沙漠公路生物防沙的植物种主要为灌木(31种)、草本(14种)、乔木(2种).     

盐池县沙蒿资源的开发与利用研究

沙葛是盐池县流动和半固定沙地上理想的固沙植物,也是具有潜在利用价值的经济植物。通过对盐池县自然条件和沙蒿资源的调查,以及对沙蒿种植与资源利用前景的分析和研究,为当地进一步利用沙蒿类植物进行区域沙漠化治理和深度开发沙漠生态产业提供理论依据。     

新疆生产建设兵团白沙湖国家沙漠公园规划思路

白沙湖沙漠公园位于阿勒泰生态区,是我国土地荒漠化威胁最为严重的地区之一,为了有效遏止该区域沙化土地扩展趋势,丰富沙漠公园的生物多样性,改善生态环境,生态系统稳定性进一步增强,建设了白沙湖国家沙漠公园。文章分析规划区域内土地、植物、动物、景观、生态等资源的特点,对资源进行综合评价,提出沙漠公园的规划定位和规划目标,"三点一线带一面"的总体规划及功能区划构想,以构建人与自然和谐发展的综合型国家沙漠公园。     

永泰青云山国家公益林植物与植被调查初报

对青云山地区国家公益林采用线路调查和标准地调查方法进行植物、植被调查,结果表明该地区物种丰富,特别是珍稀濒危植物种类较多。并研究了主要植物群落的植被类型。     

和田地区野生甘草扩繁试验研究初报

野生甘草在保护荒漠生态环境和防治土地沙漠化方面起着重要作用,近年来,因各种人为和自然因素造成野生甘草资源日益减少,导致荒漠生态环境恶化。2012年对和田地区和田县荒漠全面调查研究的基础上,进行了野生甘草断根试验研究,结果表明:甘草具有发达的根系,断根可促使根蘖苗大量繁殖,开挖距母株30 cm、深40 cm左右的断根沟对甘草断根后,母株平均长出2株新植株,平均高度达28 cm;回填土出苗株数平均为0.6株,平均高度16 cm,不回填土平均株数为6株,平均高度22 cm。经试验,采挖后不回填土或少量回填对甘草出新苗有良好的效果。     

民勤荒漠植被的初步研究

民勤荒漠植被种类贫乏，结构简单，受地下水位下降的影响，形成了以唐古特白刺为建群种的顶极群落，其它植物种群均在衰退；降水量在现实状况下以木本植物的影响很小，对秋季短生植物影响较大，本区植被的演替趋向强旱生化。     

Trillium grandiflorum height is an indicator of white-tailed deer density at local and regional scales

High densities of white-tailed deer (Odocoileus virginianus) in the U.S.A. and Canada are reducing or preventing forest regeneration, and as a result, deer function as a keystone species in some sites. Management decisions about deer require reliable population density data, which are challenging to obtain at both regional and local scales. We tested the broad-scale applicability of the indicator species approach in which forage plant height was used to estimate deer density. The maximum heights of marked and unmarked plants of the widely distributed, spring-flowering polycarpic herb, white trillium (Trillium grandiflorum) were measured across southern Ontario, Canada, over a 15-year period. A significant negative relationship was found at 10 sites between maximum plant height and estimates of deer population densities, which were derived from counts of live or culled animals and varied from 7 to 40 deers km⁻². Maximum plant height could be reliably measured within a 4-week period. The underlying mechanism driving the negative relationship between plant height and deer density was attributed to deer preferentially selecting taller plants that grew less than ungrazed plants in the subsequent year. In 16 additional sites with locally high deer populations, the mean maximum height of T. grandiflorum appeared to be a more reliable indicator of deer density than estimates based on hunter returns across the broader regional scale of the Wildlife Management Unit. The ability to assess local scale white-tailed deer densities based on measuring heights of an easily identifiable, widespread plant, provides local residents and landowners with a tool for estimating the potential impacts of deer browsing and grazing in local woodlots and forests, improving local knowledge about herbivory pressure.     

Genetic variation for carbon isotope composition in honey mesquite (Prosopis glandulosa)

Carbon isotope composition (delta(13)C) is a useful surrogate for integrated, plant water-use efficiency (WUE) when measured on plants grown in a common environment. In a variety of species, genetic variation in delta(13)C has been linked to the distribution of genotypes across gradients in atmospheric and soil water. We examined genetic variation for delta(13)C in seedlings of honey mesquite (Prosopis glandulosa Torr.), an invasive grassland shrub that thrives in the southwestern USA. Fifteen maternal families, representing progeny of 15 adult trees, were studied in three common garden experiments in a greenhouse. The 990-km east-west transect along which the adult trees were located encompasses a wide precipitation gradient, and includes mesic grassland, semiarid grassland, and Chihuahuan desert ecosystems. Genetic variation for delta(13)C in mesquite was substantial, with the rank order of half-sib families based on delta(13)C relatively stable across experiments, which were conducted under different environmental conditions. Conversely, rankings of families by mean seedling height (an index of growth rate) varied markedly among experiments. Seedlings derived from Chihuahuan desert adults emerged more quickly and had more negative delta(13)C (indicative of lower WUE) than seedlings derived from the other regions. Although delta(13)C and seedling height were not correlated, these results suggest that mesquite genotypes at the drier, western extreme of the species' range are adapted for quicker emergence and possibly faster growth than genotypes from mesic areas. Together, these traits may facilitate exploitation of infrequent precipitation events.     

印度热带干旱地区沙漠柚木(Tecomella undulata)同龄林极限林分密度与基面积模型

对用于评价印度拉贾斯坦邦热带干旱区沙漠柚木极限林分密度的公式进行了研究。对5个不同密度的林分基面积预测模型进行测试和比较,这些模型属非线性生长函数的轨迹不变量代数差形式。这些模型可根据林分变量,如优势高／公顷、立木数／公顷,预测林分基面积,还可用于评估不同造林方案。利用所收集的22块样地的数据建立模型。使用各种可能的树龄数据结构,用定性和定量标准比较了这些替代模型。使用Akaike信息准则差异统计来分析各种模型的预测能力。结果表明：Hui和Gadow提出的模型预测效果最好,推荐在本研究区域内使用该模型来预测沙漠柚木林分基面积。但是,此模型并未使用间伐林分数据,因此,不能准确地预测林木有明显自然死亡的林分基面积。     

国外木本植物抗寒性测定方法综述

文中对目前国外采用的不同抗寒性测定方法的测定原理、测定程序以及优缺点等作了较为详细的介绍。这些测定方法有全株冰冻测试法（组织褐变法）、电解质渗出率法、叶绿素荧光法、热分析法（主要用差热分析法）、电阻抗图谱法以及核磁共振显微镜图谱法和可视＋近红外线光谱法等。并简介了这些测定方法的适用性和抗寒性测定方法的研究展望。     

Water stress responses of seedlings of four Mediterranean oak species

Effects of water stress on phenology, growth, stomatal activity and water status were assessed from April to November 1996 in 2-year-old seedlings of Quercus frainetto Ten. (Quercus conferta Kit.), Quercus pubescens Willd., Quercus macrolepis Kotschy (Quercus aegilops auct.) and Quercus ilex L. growing in containers in northern Greece. All four species developed more than 50% of their total leaf area before the beginning of June--an adaptation to arid climates. Well-irrigated plants tended to develop greater individual leaf area, number of leaves per plant, total plant leaf area, height and root:shoot ratios than water-stressed plants, but the difference between treatments was not significant for any parameter in any species. Quercus macrolepis appeared to be the most drought-tolerant of the four species. It maintained the highest number of leaves of the smallest size and increased the proportion of fine roots during drought. In all species, drought caused significant decreases in stomatal conductance and predawn and midday water potentials from mid-July until the end of August, when the lowest soil water content and highest mean daily air temperatures and midday leaf temperatures occurred; however, the responses were species-specific. Among the four species, Quercus macrolepis sustained the highest stomatal conductance despite very low water potentials, thus overcoming drought by means of desiccation tolerance. Quercus ilex decreased stomatal conductance even before severe water stress occurred, thereby avoiding desication during drought. Quercus pubescens had the highest water potential despite a high stomatal conductance, indicating that its leaf water status was independent of stomatal activity. Quercus frainetto was the least drought-resistant of the four species. During drought it developed very low water potentials despite markedly reduced stomatal aperture.     

塔里木沙漠公路防护林造林树种生长动态研究

2005年测定了塔里木沙漠公路防护林塔中段不同年龄防护林造林树种的树高、冠幅、基径及分蘖数,依据不同年龄的防护林植物的形态指标建立其生长方程。分析表明,梭梭和沙拐枣的树高、冠幅、基部截面积,柽柳的冠幅生长过程都符合对数型增长,用对数方程可以进行很好的模拟;柽柳的树高和基部截面积生长符合Logistic增长模型,可以用Logistic方程进行很好的模拟。依据测定的形态指标,建立了三种防护林植物生长的数学模型,为塔里木沙漠公路防护林的经营管理提供了依据。     

Pilot study on the effects of elevated air temperature and CO<Subscript>2</Subscript> on artificially defoliated silver birch saplings

The impacts of elevated temperature and CO₂ on young silver birch (Betula pendula Roth) saplings after 0, 25, 50 or 75% artificial defoliation were assessed by measuring plant height and dry mass of aboveground compartments and roots and various morphological and physiological variables. Defoliation either increased or decreased plant growth depending on the severity of damage and the climatic treatment. At 21 °C and 400 mg L^?1 CO₂, defoliated plants were not able to compensate for the lost foliage, but growth compensation and adaptation to the changed conditions were greater; growth of young defoliated silver birch saplings increased, which led to increased height and a tendency to enhance final aboveground and root biomass and leaf nitrogen and carbon content compared to the nondefoliated controls. Nevertheless, the short-term effect of the different climatic conditions did not result in a significant overgrowth of defoliated plants. A slight increase in temperature and CO₂ were the most acceptable conditions for defoliated plants; however, a 4 °C increase with correspondingly higher CO₂ was more stressful as shown by less growth in height and biomass allocation to leaves, stems and roots. The findings from the pilot experiment are more applicable to young birch trees, but stress on young trees may be reflected in future tree growth.     

兰新线清水段铁路防沙体系植物种适宜性研究

在荒漠地区的铁路防沙体系建设中，植物种的表现是决定防沙体系成败的关键因素之一。因为在极端干旱的荒漠地区，所采用的植物种不仅需要适应气候条件并能够正常生长，同时还必须具有较好的固沙防沙功能。本文根据各参试植物的保存率、冠幅、株高、地表分枝数、地径和抗病虫鼠害及自然灾害能力等指标进行模糊综合评价，最终选择出沙拐枣扦插造林，花棒、柠条、沙柳、柽柳等适于河西荒漠地区的植物种。