盐碱地营造沙棘林技术研究

通过3年（1998-2000年）沙棘改良盐碱土试验的结果表明，栽植沙棘二年后降低土壤pH值0.1，含盐量降低0.01％-0.02％，有机质增加0.21％左右，虽然试验年限短，但沙棘有改良土壤效果。试验结果指出沙棘在pH值8.77-9.18区间栽植可以成活，但pH值8.77以上有一定影响，沙棘是一种抗逆性强，生态作用明显的树种，耐涝性较差。     

陕西省沙棘资源建设稳步发展

1 沙棘资源建设自1985年钱正英同志提出:“以开发沙棘资源作为加速黄土高原治理的突破口”的号召以后,陕西省对沙棘资源的建设高度重视,相继开展了沙棘资源普查、良种选育、丰产林及防护林建设和天然林保护等工作.在全省适生的黄土高原沟壑区、风沙区大力发展人工沙棘林,截止1992年底,陕西省7年共营造人工沙棘林71.98万亩,累计达到130.53万亩,加上原有的天然资源总面积达323.93万亩,为陕西分沙棘资源的开发利用奠定了一个可靠的基础.     

盐碱地沙棘造林试验研究

齐齐哈尔市园艺研究所在完成了沙棘盐碱地栽培试验基础上进行了沙棘盐碱地造林试验研究，进行了不同造林模式比较，初步确定了沙棘盐碱地造林模式。     

小流域水土保持综合治理与山区林业建设：—兼论沙棘资源建设

小流域水土保持综合治理是山区治理开发的基本道路。在小流域综合治理中,林业始终是主导的关键措施。沙棘为广生态幅植物,沙棘资源建设已经同小流域水土保持综合治理紧密联系起来,沙棘已成为生产中受欢迎的主要造林树种。沙棘资源建设与小流域综合治理的结合,才能确保沙棘永续不断的生命力。     

结合重点流域治理 进行沙棘资源建设

按照甘肃省沙棘资源开发协调小组的统筹安排,甘肃省水土保持部门的任务是结合重点流域治理,进行沙棘资源建设.面上的沙棘造林和开发利用,由省沙棘办统一管理.1990年全国沙棘会议以来,甘肃省把沙棘作为小流域荒山造林的先锋树种,采用统一规划,集中连片的方法,大面积营造沙棘林,取得了显著成效.3年以来在700条重点小流域内营造沙棘林37.85万亩,育苗留床面积0.86万亩,使全省小流域沙棘面积累计达到68.38万亩,比3年前翻了一番.在沙棘资源建设的组织领导、政策方法,以及育苗、造林技术等方面也积累了一套符合甘肃实际的经验.3年来小流域沙棘资源建设的主要做法和体会是:     

青海沙棘资源开发利用现状及对策

青海省地处我国青藏高原东北部,是我国沙棘分布的重要省份之一,同时也是沙棘在世界上分布海拔最高的地区(平均海拔3000m).近多年沙棘开发利用的实践表明,沙棘在生态工程建设及深度开发利用方面蕴藏着巨大的价值,对实现青海省生态工程建设规划和林业可持续发展战略,尽快使山区、沙区群众脱贫致富,促进地方经济发展,加强沙棘资源建设和产业发展具有重要的意义.     

提高沙棘造林成活率的机理与途径

通过研究黄土高原地区沙棘造林后幼苗水分平衡与成活率的关系，证明维持幼苗水分平衡是提高沙棘造林成活率的关键环节，据此提出了几种应在生产中推广的抗旱造林技术措施。     

沙棘无性繁殖与沙棘园营造技术

沙棘是胡颓子科沙棘属的落叶灌木或小乔木。中国沙棘（HIPpophaerhamnoldesL．subsp．SlnenslsRollsi）具有许多优良特性,是营造水土保持林、防风固沙林、薪炭林和饲料林的优良灌木,已被国家列为重要经济树种之一。并提出了“以开发沙棘资源作为加速黄土高原治理的一个突破口”。自80年代中期以来,我国有组织有领导地进行沙棘资源开发利用,取得了举世瞩目的成就,并正向深度发展。我国目前沙棘加工所用原料,主要靠天然林或实生人工林来提供,这些林分产果量很低,难以满足现代加工业的需要。因此,需要大量营造高产优质的人工沙棘园…     

我国沙棘事业的发展

我国沙棘事业的发展高志义，火树华（北京林业大学）我国大规模地应用沙棘这一优良灌木树种于防护林体系工程建设、水土保持小流域综合治理和沙棘产品的开发利用已经整整１０年了。实践证明：１０年来，在沙棘资源建设和沙棘产品开发利用的过程中业已显示出其巨大的生态经...     

沙棘育苗造林技术

分析了沙棘的生态特征,从采种、育苗、整地、造林、病虫害防治等方面论述了沙棘的育苗及造林技术,以期为沙棘的广泛栽培提供技术参考。     

不同磷水平下刺梨实生苗生长及根系形态特征与内源激素含量的关系

【目的】探究不同磷水平对‘贵农5号’刺梨实生苗生长、根系形态变化的影响及其与内源激素的相互作用,了解刺梨应对低磷胁迫的适应策略,为喀斯特地区低磷土壤刺梨的磷养分管理和生长调控提供科学依据。【方法】采用基质培养方法,设5、25、45、65和85 mg·L^-1有效磷含量的5个供磷水平处理,对不同处理的生长和根系形态指标及叶、根中内源激素含量进行测定,解析不同磷水平下根系形态与内源激素含量变化的关系。【结果】1) 45 mg·L^-1磷水平下实生苗生长的最好,整株生物量、主根长度、总根尖数和根的总长度、总体积、总表面积、平均直径、侧根长度和数量、一级侧根密度均最大,根和叶中的GA₁₊₃含量最高,ABA含量最低。2)供磷水平低于或高于45 mg·L^-1后,植株生长受到抑制,生物量明显减小,GA₁₊₃含量降低,ABA含量增大,上述根系形态指标变小。在5 mg·L^-1的低磷胁迫下,植株根冠比、2级、3级侧根密度和根毛的密度及长度达到最大。3)根和叶中的IAA及ZR含量随磷水平的降低而增大。4)不同磷水平下植株的生长指标和生物量大小与根和叶中的IAA和ZR含量间均表现出极显著(P<0. 01)的一元二次非线性回归关系,与GA₁₊₃和ABA的含量分别呈极显著(P<0. 01)正相关和极显著(P<0. 01)负相关。供磷水平过低、过高对植株生长的抑制是IAA、ZR、GA₁₊₃、ABA含量改变后协同作用的结果。低磷水平下根的生长抑制与叶和根中的IAA、ZR和ABA含量增大和GA₁₊₃含量降低有关,高浓度的GA₁₊₃和低浓度的ABA能促进主根的伸长和侧根的形成,而高浓度的IAA和ZR对根毛的形成及伸长和增加根毛的密度有促进作用。【结论】45 mg·L^-1磷水平下刺梨实生苗生长和根系发育最好,主根长度、总根尖数和根的总长度、总体积、总表面积、平均直径、侧根长度和数量、一级侧根密度最大。降低或提高磷水平后植株生长受到抑制,上述根系形态指标随之变小。低磷胁迫下刺梨实生苗根冠比和2、3级侧根密度、根毛密度及长度明显增大。供磷水平变化导致刺梨实生苗叶和根中IAA、ZR、GA₁₊₃、ABA的含量发生改变,并共同对植株生长和根系形态变化产生协同调控作用。根冠比的增大,2、3级侧根密度和根毛密度及长度的增加是刺梨实生苗应对低磷胁迫采取的适应策略,根和叶中高水平的ZR和IAA发挥重要的促进和调控作用。     

一个世纪来黑龙江省森林景观动态研究

With the help of GIS tool of ARC/INFO,ARCVIEW and FRAGSTATS,the map of forest resource distribution of Heilongjiang Province was analyzed in 1896,1949 and 1981.Using total area,mean patch size,patch density,coefficient of patch size variation,mean patch fractal dimension and mean shape index,we studied the change of forest landscape pattem and the change of each patch types in this region.As a result,the total area of forest landscape and mean patch size decreased sharply,the quantity and density of patches increased,the juxtaposition of patches weakened,the shape of patch tended to become regular,and the border of patch simplified.All these showed that the forest landscape of this area tended to fragment gradually,and the fragment of Korean pine forest is the severest.the diversity of whole forest landscape and the eveness of landscape types distribution reduced gradually.Human impact,instead of climate change and forest community succession,is the most important reason for such dramatic chages.     

竹材半纤维素提取及其解聚过程研究进展

在当前碳达峰、碳中和的目标下，开发制备高附加值的半纤维素化学品具有广阔的应用前景，而且对人类社会可持续发展具有重要意义。但半纤维素由于其复杂和不均一的结构致使研究和利用受到限制，存在着易降解、收率低、纯化困难、成本高等问题。因此，如何提高木质纤维原料中半纤维素及其解聚产物的提取率成为研究的热点与重点。文章对近年来提取半纤维素及其解聚产物的研究进行了综述，简述了提取半纤维素的不同预处理方法，并分析了一定的降解方法得到半纤维素的解聚产物——木寡糖和木糖；在此基础上，为研究竹材半纤维素提取技术与工业应用提出了建议；最后，结合发展趋势，特别是针对竹材应用领域，指出了未来半纤维素及其解聚产物的发展方向。     

Estimation of genetic variances in flood tolerance of poplar and selection of resistant F1 generations

Five Aigeiros section poplar clones were adopted as parents to produce five full-sib families through cross-breeding. Morphological, ecophysiological, and growth characteristics of the five parents and their 15 superior F1 generations were investigated during 45 days of flooding followed by a 10-day recovery period. Cuttings were subjected to two treatments: watered (control) and flooded to 10 cm above the soil surface. Results showed that flooded cuttings showed significant reduction in growth of height, root-collar diameter and leaf area, and root and total biomass yield. All 20 clones formed hypertrophied lenticels and adventitious roots by day 6–14 of flooding. In flooded cuttings, net photosynthesis, stomatal conductance, transpiration, and chlorophyll fluorescence were decreased significantly compared with the control. After flooding ended, all plants recovered rapidly. Generally, progenies showed higher growth of height, root-collar diameter, root biomass and leaf area than their parents both under flooding and control conditions, showing that heterosis existed in F1 generations, regardless of flooding. However heterosis was lower under flooding conditions than in the control. Under flooding, the highest heterosis of higher-parent in height and root-collar diameter were 68.63 and 20.83%, respectively. Variability of flood tolerance among progenies was clear in growth of height and root-collar diameter. Selection criteria for parents in cross-breeding were different between control and flooding. Relative effect values of the specific combining ability (SCA) and relative effect values of the general combining ability (GCA) of parents were more important than their flood tolerance. Progenies with a higher level of flood tolerance could be obtained, even from parents intolerant to flooding. In terms of breeding, height growth would be most important characteristic to measure in flooding conditions, and root-collar diameter growth was also very useful. Based on all measured values, the tested 20 clones were classified into three groups using hierarchical cluster analysis. Clones Lu, E4, E9, E29, A2, A8, A9, B1, B3, B4, and D8, were flood-tolerant. Clones Lf, Ha, Lm, D1, D7, F9, and F21 were moderately flood-tolerant. Clones Sm and F13 were flood-susceptible.     

福建省樟树溃疡病病原菌的分离与鉴定

为了明确福建省樟树溃疡病的病原菌种类,对福建省福州市仓山区、三明市明溪县、南平市建阳区和顺昌县4个地区采集的樟树枝干溃疡样本进行分离、纯化和致病性分析,将病原菌进行系统形态学观察,并结合代表菌株的核糖体基因内转录间隔区(ITS)、翻译延伸因子(EF-1α)、RNA聚合酶Ⅱ大亚基(RPB2)和β-微管蛋白(BT)基因序列进行同源性分析,构建进化树,最终确定病原菌种类。结果表明,在福建省不同地区内采集到的75份樟树溃疡样本,经过组织分离、纯化和致病性检测,得到43个病原菌株,根据观察病原菌的菌丝生长状态和孢子特征,并结合系统进化树的结果,得到小新壳梭孢(Neofusicoccum parvum)、可可毛色二孢(Lasiodiplodia theobromae)、假可可毛色二孢(Lasiodiplodia pseudotheobromae)和Lasiodiplodia iranensis 4种类型菌株。接种菌株后发病症状与野外发病症状相同,但致病程度不同,其中小新壳梭孢最强,可可毛色二孢次之,L.iranensis最弱。     

Chemical study and medical application of saponins as anti-cancer agents

Saponins are a group of naturally occurring plant glycosides, characterized by their strong foam-forming properties in aqueous solution. The presence of saponins has been reported in more than 100 families of plants out of which at least 150 kinds of natural saponins have been found to possess significant anti-cancer properties. There are more than 11 distinguished classes of saponins including dammaranes, tirucallanes, lupanes, hopanes, oleananes, taraxasteranes, ursanes, cycloartanes, lanostanes, cucurbitanes and steroids. Due to the great variability of their structures, saponins always display anti-tumorigenic effects through varieties of antitumor pathways. In addition, there are a large amount of saponins that still either remain to be trapped or studied in details by the medicinal chemists. This article reviews many such structures and their related chemistry along with the recent advances in understanding mechanism of action and structure–function relationships of saponins at the molecular and cellular levels. These aglycones have been described and their classification and distribution have been listed in the review. Some special saponins with strong antitumor effects have also been exhibited. Ginsenosides, belonging to dammaranes, have been found beneficial targeted on inhibition of tumor angiogenesis by suppressing its inducer in the endothelial cells of blood vessels, and then on prevention of adhering, invasion, and metastasis of tumor cells. Dioscin, one of the steroidal saponins, and its aglycone diosgenin also have been extensively studied on its antitumor effect by cell cycle arrest and apoptosis. Other important molecules discussed include oleanane saponins such as avicins, platycodons, saikosaponins, and soysaponins along with tubeimosides.     

Socioeconomic research in agroforestry: a decade in review

Agroforestry research in academia and government and non-governmental agencies began by focusing on biophysical aspects. As this science represents a series of practices implemented by individual farmers, it requires in-depth social and economic analyses to assess economic feasibility of agroforestry systems, factors influencing the adoption of agroforestry, monitor the relevance and effectiveness of investigations, and guide future research efforts. This study presents literature dealing with socioeconomic issues in agroforestry research from interdisciplinary peer-reviewed journals, book chapters, and gray literature from 1992 to 2002. Over 500 publications were analyzed to determine relative dominance of geographical regions, types of analyses, agroforestry technologies, and socioeconomic issues. Trends were examined over time and by region. Overall, the body of literature exhibits an increasing trend toward regional and analytical diversity over time. Some deficiencies of regional and thematic nature were observed, which included underrepresented temperate regions and technologies such as riparian buffers, as well as only a small number of papers dealing with gender and property rights. These suggest opportunities for future investigations.     

漆树科4种植物次生韧皮部的解剖比较

【目的】以漆树科3属4个种(盐肤木、青麸杨、黄连木和黄栌)的次生韧皮部为研究对象,阐明各物种次生韧皮部组成细胞的结构特征和分布规律,为植物次生韧皮部组成细胞结构特征与分泌结构之间的关系研究提供理论依据,并为漆树科植物系统演化的相关研究提供参考依据。【方法】采集盐肤木、青麸杨、黄连木和黄栌的树皮样品(样品含形成层、次生韧皮部及周皮,不含次生木质部),采用比较解剖学的方法,对漆树科4种植物的次生韧皮部的结构特征、组成细胞的构成及其排列方式进行比较,并对4种植物的乳汁道结构进行研究。【结果】漆树科4种植物次生韧皮部均是由筛管分子和伴胞、韧皮薄壁组织细胞、射线细胞、乳汁道和韧皮纤维构成,呈切向带状相间排列。黄连木、青麸杨和盐肤木的具功能韧皮部和无功能韧皮部分界明显;青麸杨的射线细胞在无功能韧皮部中倾斜分布,其余3种植物均为整齐纵向排列;青麸杨的乳汁道为分枝型乳汁道,其他3个种的乳汁道均无分枝,仅有少量相邻乳汁道融合现象发生;黄连木和黄栌次生韧皮部内分布有大量的韧皮纤维,青麸杨韧皮部中较少,而盐肤木韧皮部中无韧皮纤维分布。【结论】漆树科4种植物次生韧皮部组成细胞及乳汁道结构存在一定差异,青麸杨乳汁道是目前为止漆树科植物中发现的较为稀有的分枝型乳汁道,研究结果能够为漆树科系统进化研究提供参考依据。     

气候因子对竹子生长的影响研究综述

竹子是集经济、生态和社会效益于一体的优良林种,是区域农村经济社会发展的重要资源和生态环境保护的重要屏障.温度、水分、光照、大气组分等的变化直接影响着竹子的生长发育和分布.该文从主要气候因子对竹子生物学特性、生态学特征及其分布和经济产出的影响研究现状进行了综述,提出了今后需要重点开展的相关研究内容.     

STUDIES ON STRUCTURE AND FUNCTIONS OF MONGOLIAN OAK FORESTS

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