云南橡胶园微量元素含量分析初报

通过对云南橡胶园植胶土壤和橡胶树叶片微量元素含量进行测定和分析,初步拟出云南橡胶树叶片微量元素养分含量的适宜范围,其中铜12.00～13.50mg/kg,锌30.00～40.00mg/kg,铁110.00～170.00mg/kg,锰350.00～600.00mg/kg,硼18.00～35.00mg/kg和钼0.05～0.20mg/kg;同时根据云南胶园微量元素营养水平,建议对不同土壤类型的胶园开展施用钼肥和硼肥的试验研究。     

基于GIS分析技术的橡胶树叶面积测定

利用GIS空间分析方法对标准面积的正方形、梯形等进行面积计算,GIS法提取的面积与准图形面积之间相对误差均小于0.54%,认为该法可以用于图形面积测算。对GIS法提取的橡胶树叶片面积结果与叶面积仪测量的结果进行相关分析和配对样本T测验,结果GIS法与叶面积仪法测量橡胶树叶片面积极显著相关且差异不显著。因此认为GIS法能够代替叶面积仪对橡胶树叶片面积的测定,且具有简便、精确、高效的特点。     

应用~(10)B示踪技术研究杨树幼苗对叶面硼的吸收和分配

[目的 ]研究不同硼肥条件下杨树对硼肥的吸收、分配和再转运能力,为杨树人工林的培育和经营提供参考。[方法 ]采用新疆杨(Populus alba var. pyramidalis Bunge)为试验材料,进行温室控制条件下的砂培试验,在营养液中添加不同浓度硼酸,并通过下部成熟叶片饲喂富~(10)B硼酸(H_3~(10)BO_3),记录杨树生长情况,测定各部位硼含量。[结果 ](1)砂培条件下,降低营养液中硼浓度(LB),新疆杨生物量和硼积累量显著下降,上部叶片硼浓度显著下降,分配给幼嫩叶片的硼占植株硼积累总量的比例显著下降。(2)在LB的基础上饲喂叶面硼肥(LB+F),可补充上部叶片硼浓度,在一定程度上缓减植株生物量和硼积累量的变化;大部分从叶面肥中吸收的硼被保留在饲喂叶片中,还可被再转运到幼嫩叶片(31.68%)、根(5.27%)和茎(1.06%)。(3)在营养液硼浓度足量(NB)的基础上饲喂叶面硼肥(NB+F),茎部硼浓度显著上升,但对根、叶硼浓度和各部位生物量的影响不明显;与LB+F相比,NB+F从叶面肥中吸收的硼较少,仅为前者的15.6%。[结论 ]低硼胁迫导致新疆杨幼嫩叶片的硼分配减少,影响植株生长,成熟叶片吸收的叶面硼肥可再转运并分配给以幼嫩叶片为主的其它部位,通过施叶面硼肥可弥补根际硼亏缺对植株生长的影响。     

橡胶树叶片花色素苷的提取与稳定性及其品种间含量变化研究

为探讨不同橡胶树品种叶片中花色素苷含量特征,首先通过对不同提取材料、提取液和提取时间的研究,以确定巴西橡胶树叶片花色素苷的最佳提取条件,然后对影响其稳定性的因素进行了测试,并利用最佳的橡胶树花色素苷提取条件对抗寒性不同的橡胶树品种的花色素苷含量进行测定。结果表明,用1%盐酸乙醇作为橡胶树古铜期叶片花色素苷提取液的效果最好,最佳的提取时间为6 h;橡胶树叶片花色素苷的稳定性受p H值影响较大,随着p H升高其稳定性明显下降,其对光强也比较敏感,但对温度较不敏感,可见,黑暗和酸性条件能较好地保持花色素苷的稳定性;不同抗寒性橡胶树品种的花色素苷含量存在差异。综上可见,本研究建立的花色素苷提取条件及其稳定性保持条件为后续橡胶树花色素苷的研究奠定了基础。     

电感耦合等离子体发射光谱法同时测定集中式生活饮用水源中13种金属元素试验

利用美国PE公司生产的Optima 8300电感耦合等离子体发射光谱仪同时测定了集中式饮用水源中铜、锌、铅、镉、铁、锰、钼、钴、铍、硼、镍、钒、钡等13种元素。试验将水样用0.45μm滤膜抽滤,取中段滤液100mL,加浓硝酸0.2mL。ICP采用轴向观测方式,同时采用石英同心雾化器加石英旋流雾化室,直接分析样品,减少背景干扰和其它元素干扰,提高了分析的灵敏度。结果表明:线性范围好,各元素相关系数均≥0.9995;灵敏性好,方法检出限为0.3~30μg/L;重现性好,各元素的相对标准偏差(RSD)为0.22%~3.89%;准确度高,样品加标回收率为95.0%~104.0%,并对标样进行了测定,数值均在允许范围内。该方法可多元素测定,操作简便、快速灵敏、线性范围宽、检出限低、结果准确可靠,能够满足集中式饮用水源水的测定要求。     

森林土壤有效硼的测定方法研究

本文通过单因素试验,利用稳定度、精度和变异系数作为评价指标,优化土壤样品浸提液中硼含量测定方法。基于硼在弱酸性水溶液中易与甲亚胺生成黄色络合物,在420 nm具有特征波长,在0~10 mg·10 ml-1测定范围内符合朗伯-比尔定律,灵敏度为0.0013mg·cm-2;同时,浸提液可直接利用电感耦合等离子体发射光谱(ICP-AES)进行测定,其检出限为0.0041,变异系数为3.49%,通过与国家土壤有效态一级标准物质测试相比较,ICP-AES、比色法变异系数分别为4.24%、20.82%,测定结果 ICP-AES优于比色法结果。     

叶面喷钙对金丝小枣矿质养分变化规律研究

为了解金丝小枣需钙规律,从而为金丝小枣合理施用钙肥提供理论依据,以金丝小枣为试材,分别对其叶面喷施有机钙(0.2%柠檬酸钙)和无机钙(0.2%硝酸钙),并于果实发育不同时期测定叶片、果实中矿质养分含量。结果表明:在金丝小枣发育过程中,叶片中钙含量呈不断增加趋势,果实中钙含量随生育期变化不断降低。喷施钙素显著提高了叶片中氮、磷、钙、硼含量,并显著降低了叶片中锰、锌含量。喷施硝酸钙显著提高了叶片镁含量。喷施钙素显著提高了果实中磷、钙、硼含量,喷施柠檬酸钙显著降低了果实中镁、硼、锌含量。综上所述,喷施钙素能显著提高叶片及果实中大多数矿质养分含量,故钙素对于维持树体养分比例平衡具有重要作用。     

电导法配合叶片SPAD值鉴定橡胶树无性系的抗旱性

以田间鉴定为依据,选择橡胶树6个优树无性系为材料,对叶片的相对电导率、相对含水量、持水力及SPAD值进行测定。结果表明,在干旱胁迫期间,橡胶树不同无性系的叶片相对电导率和含水量存在极显著差异,表现出抗旱性强的无性系其相对电导率低,相对含水量高,测定的SPAD值也相对较高;相关性分析表明,SPAD值与胁迫后电导率上升幅度、相对含水量及胁迫21 h持水力间呈显著相关(P0.05)。运用电导法配合叶片SPAD值对橡胶树种质资源的抗旱性进行规模化筛选简便快捷,结果具有一定可靠性。     

如何诊断花木缺少哪种元素

如何诊断花木缺少哪种元素花木在长生发育过程中需要大量的氮、磷、钾、钙、镁等元素，同时还需要很少的铁、硼、锰、锌、铜、钼等微量元素。花卉缺少某种元素时，就会表现出相应的缺素症状，如缺氮症状为生长势弱，叶色浅绿，基部叶片发黄或呈浅褐色；缺磷时叶片兰绿且略...     

孔雀绿—磷钼杂多酸分光光度法测定油茶叶片中的无机磷

用碱性染料孔雀绿,在非离子表面活性剂OP和明胶存在下,与磷钼杂多酸形成显色缔合物测定油茶叶片中无机磷(痕量)。结果表明,不同油茶品种,其叶片中无机磷含量存在着较大的差异,同时表明,用本法测定痕量磷时,稳定性好,灵敏度高,用混合还原剂可消除试液中砷和硅的干扰,是测定植物叶片中痕量磷含量的较佳方法。     

林木低磷胁迫适应机制研究进展

土壤有效磷缺乏在自然环境中是一种非常普遍的现象,近年来世界各国针对植物的觅磷和耐磷机制进行了大量研究,然而目前相关的综述性报道多限于农作物,对林木低磷胁迫适应性的综述性报道尚不多见。在长期进化过程中,林木为利用土壤中现有的含量极低的有效磷,形成了各种适应低磷胁迫的机制。文中从林木根系的形态学变化、根系分泌物对土壤难溶性磷的活化作用、林木对土壤低浓度有效磷的吸收利用以及应对低磷胁迫的遗传调控等方面综述了低磷环境中林木的适应机制,为揭示林木对缺磷环境的适应机理、发掘林木自身对土壤有效磷高效率的吸收利用能力、以及进一步筛选林木的磷高效品种和合理经营管理人工林提供参考。     

板栗优质高产途径及其技术措施的研究

增加结果母枝粗度、减少生理落果、改善内腔光照条件、适当控制树冠体积、提高栗棚内的栗果数与栗果重、缩短由小年到大年的时间,以及适时防治病虫害是板栗优质高产的有效途径。同时提出了实现各途径的主要技术措施。     

高等教育教学研究项目和教学成果综合管理系统的设计与实现

高校教学研究项目管理手段已经难以适应现阶段教研项目发展的需要,提高教学研究项目的管理水平,促进教学成果的推广和应用,实现信息化势在必行.本系统充分结合项目管理思想和实际需求,进行需求分析、结构设计、功能模块设计和功能实现,以东北林业大学为试点,最终设计出一款适应于普通高校教学研究管理工作的,操作简便、易学易用、科学有效的通用系统.该系统的设计实现和应用有助于高校项目管理实现科学化、规范化和高效化,对推动高校教学改革的深化和教育质量的提高具有重要意义.     

我国油茶产业发展现状与对策建议

为梳理制约我国油茶产业发展的瓶颈问题，文中介绍我国油茶产业发展历程，综述油茶产业发展现状，从良种繁育、栽培管理、加工和科技服务等方面分析存在的问题，并针对问题提出相应的建议:加大良种选育监管力度，限制认可度低的良种推广应用；建立良种基地动态评估和奖惩机制，加大育种资金投入；整改现有采穗圃，提高良种繁育单位准入门槛；扩大优良良种使用范围，加强良种繁育技术培训；分地区细化高效栽培和低产林改造技术；建立高产示范基地和专家库，引导经营者科学经营；推进油茶全产业链机械化建设步伐，完善加工工艺；制定油茶产品质量标准，建立油茶产业高质量发展公共服务平台；加强公共品牌建设与宣传，提高消费者对油茶品牌认知度；组建油茶科技服务团队，完善油茶科技服务体系。期望通过这些建议能够助力我国油茶产业高质量发展，使油茶产业加速从千亿向万亿规模迈进。     

Forest responses to climate change in the northwestern United States: Ecophysiological foundations for adaptive management

Climate change resulting from increased concentrations of atmospheric carbon dioxide ([CO₂]) is expected to result in warmer temperatures and changed precipitation regimes during this century. In the northwestern U.S., these changes will likely decrease snowpack, cause earlier snowmelt, increase summer evapotranspiration, and increase the frequency and severity of droughts. Elevated [CO₂] and warmer temperatures may have positive effects on growth and productivity where there is adequate moisture or growth is currently limited by cold. However, the effects of climate change are generally expected to reduce growth and survival, predispose forests to disturbance by wildfire, insects, and disease; and ultimately change forest structure and composition at the landscape scale. Substantial warming will likely decrease winter chilling resulting in delayed bud burst, and adversely affect flowering and seed germination for some species. The extent of these effects will depend on the magnitude of climate change, the abilities of individual trees to acclimate, and for tree populations to adapt in situ, or to migrate to suitable habitats. These coping mechanisms may be insufficient to maintain optimal fitness of tree populations to rapidly changing climate. Physiological responses to climatic stresses are relatively well-understood at the organ or whole-plant scale but not at the stand or landscape scale. In particular, the interactive effects of multiple stressors is not well known. Genetic and silvicultural approaches to increase adaptive capacities and to decrease climate-related vulnerabilities of forests can be based on ecophysiological knowledge. Effective approaches to climate adaptation will likely include assisted migration of species and populations, and density management. Use of these approaches to increase forest resistance and resilience at the landscape scale requires a better understanding of species adaptations, within-species genetic variation, and the mitigating effects of silvicultural treatments.     

Current Research and Development on Deformation and Fixation of Bended Wood and Wood-based Composites

There are many advantages of bended wood,such as good-looking shape,simple process and low cost.The product,however,is easy to get recovery,which is urgent to be dealt with.This paper concludes the features of deformation and recovery of bended wood and wood-based composites and summarizes four treating methods to keep dimensional stability.Compared to bended solid wood,some elementary perspectives on the research of bended wood-based composites are presented.The purpose of this paper is to suggest:1)to investigate the optimum heating time and temperature that bended wood and wood-based composites need from the formation of deformation to the recovery and to the permanent fixation,according to its changes of dimensional stability such as curvature radius;2)to measure the composites comprised of wood and adhesives on the changes of stress relaxation,dynamic viscoelasticity and crystal1ization field;3)to quantitatively analyze changes of the major components in wood cell wall polymers as well as the composites under heat/steam treatment and untreated conditions.It will be helpful for subsequent research to clarify on the mechanisms of permanent fixation of bended wood and also contribute to that of wood-based composites.     

白梭梭同化枝对干旱胁迫的生理生态响应

对白梭梭同化枝自然水分胁迫下的季节抗旱特征进行研究。结果表明:自然干旱胁迫条件下,不同生长发育时期同化枝的主导抗旱生理因子不同。5月31日至6月29日盛花期间,同化枝内源ABA含量甚微,气孔导度值与光合强度处于生长发育过程的最高水平,可溶性糖含量呈现下降趋势,而脯氨酸含量略有增加,植物通过渗透调节作用适应此阶段轻度干旱胁迫;6月29日至7月26日盛夏期间,ABA迅速积累,气孔导度值降为生长发育过程的最低值,叶绿素分解,可溶性糖与脯氨酸均呈现快速积累趋势,且可溶性糖积累强度大于脯氨酸;8月9日至8月22日同化枝生长发育后期,ABA急剧积累为生长发育过程的最高浓度,气孔导度值有所增大,脯氨酸和可溶性糖保持在高水平平稳变化。此阶段高浓度ABA调节植物生理过程适应干旱的效应受CTK、IAA两种内源激素的抑制,进而抑制脯氨酸和可溶性糖的继续积累。     

培育森林资源要走内涵增长的新路子

本文提出了培育森林后备资源的指导思想要实现６个转变：（１）森林更新方式由营造成片人工纯林为主向“人天混”上转变，（２）森林培育方式由粗放经营向集约经营上转变；（３）森林培育重点由人工造林向抚育天然幼壮林上转变；（４）种苗工作由常规技术向生物遗传工程技术上转变；（５）经营机制由单一全民造林向多元化造林上转变；（６）营林机构单一职能部门向公司化转变。这些举措对森林经营和营林体制改革都具有现实意义。     

外来杨树遗传资源及其存在的问题

简要回顾了我国不同时期引进的杨树遗传资源。在总结了外来杨树资源对推进我国杨树栽培品种化和育种上起到了重大作用的同时，针对目前存在的问题提出了今后应加强的研究工作：必须加强对基因资源研究的投入，建立完善的资源保存基地，增强今后杨树育种创新能力；扩大资源评价研究的规模和深度，使外来杨树资源利用更有预见性；杂种杨树的基因渗入可能会改变原有乡土杨树的遗传多样性和完整性，对人工育成品种导人不育基因是防止基因污染的关键技术措施，应作为今后推广新品种的一项必备新指标；为应对我国气候变化可能为杨树集约栽培带来的有益性（栽培区北移和生长期延长）和潜在的生态风险（干旱缺水）及病虫灾害所需求新品种作前瞻性准备，必须从现在起开始新一轮杨树种质资源的收集和研奔。     

Contour hedgerows and other soil conservation interventions for hilly terrain

Management of hillside cropland is a critical issue in the tropical world because of the extreme pressure on the land itself that results from the decision to farm what would be considered in many countries as marginal land. Practices such as contour hedgerows and other soil conservation techniques could be more effective if they are installed or aligned in such a way that they maximize the land capability potential in various sectors of typical soil catenas; and if biological control crops including trees, grasses and shrubs are spatially arranged to take advantage of their intrinsic biological potential to accommodate to the edaphic dissimilarities of steep hillsides. Spatial arrangements of annual and perennial crops in natural geosequences are discussed, and suggestions are given on how spatial considerations can be matched to preferred crop mixes of trees, shrubs and grasses, in an attempt to halt erosion and better protect the environment. Land use planning on a physiographic and soil capability basis is proposed, but acknowledges that effective implementation is subject to a determined campaign to extend both the theory of sound land management and the provision of technical assistance to peasants to demonstrate the concepts and to interpret the results of the practices. This paper explores certain aspects of physiographic and edaphic similarities and constraints of peasant farming practices on steep slopes, and offers some theoretical bases upon which hedgerow technology can be applied to improve water and plant relations, ameliorate environmental effects and be initiated by individual farmers at little cost. A range of other soil conservation or agroforestry techniques, as used in Haiti is described; and a simple monitoring or measurement model to determine the amount of soil saved is provided, and the possibility of teaching the methods to minimally trained field technicians is explored, pursuant to encouraging farmers to give greater attention to the value of soil conservation and proper land use planning. Presented at the 6th International Soil Conservation Organization Conference, Soil Conservation for Survival, Addis Ababa, Ethiopia, 6–18 November 1989