抗蒸腾剂对枣树幼苗几项生理指标的影响

研究了1年生灰枣嫁接苗在移栽过程中,喷施不同浓度的薄膜型抗蒸腾剂(Transfilm)对其生理指标的影响。结果表明:抗蒸腾剂能抑制枣苗中MDA含量的升高,同时抗蒸腾剂能提高枣树幼苗中可溶性糖和可溶性蛋白的含量;处理浓度以50ml.L-1的效果较好。     

抗蒸腾剂在华北紫丁香上的应用研究

抗蒸腾剂是指作用于植物叶表面,能降低蒸腾强度,减少水分散失的一类化学物质。文章在常见的园林绿化植物华北紫丁香的叶面上喷施抗蒸腾剂,测定喷药后不同阶段的光合速率、蒸腾速率、叶绿素相对含量和叶片含水量。结果表明:喷药后,植物叶片的光合速率和蒸腾速率与对照相比,出现了显著的下降,而叶绿素相对含量和叶片含水量没有显著差异。     

河西走廊沙漠人工林群落结构特征

在实地踏查的基础上,设置典型调查样地,调查分析了河西走廊沙漠人工林植物的物种组成和群落类型,描述了物种的地理成分、区系特征和生活型谱。结果表明:1)河西走廊沙漠人工林共有种子植物48种,分属14科41属,物种组成以藜科、禾本科和菊科等植物为主。2)群落植物的科、属、种区系成分类型多样,温带成分占优势,其次为地中海区-西亚-中亚分布成分,具有温带荒漠性和古老性;科的分布型有3个分布型2个亚型,属和种的地理成分可归入8个分布型4个亚型;生活型谱以1年生植物(37.5%)为主,地下芽植物(27.1%)次之。3)研究区植被可划分为3个典型群落:梭梭群落、胡杨群落和红柳群落。梭梭群落是主要建群种,分布面积广、物种数较多,优势种梭梭的重要值在0.34~0.73。胡杨群落和红柳群落分布面积少,群落盖度较低,植被稀疏。     

自然干旱胁迫下喷施抗蒸腾剂对砂生槐生理特性的影响

以西藏砂生槐为供试材料,叶面喷施不同质量浓度的抗蒸腾剂溶液,干旱处理后测定砂生槐叶片叶绿素含量、脯氨酸含量等抗旱生理指标的动态变化,研究抗蒸腾剂对提高砂生槐抗旱性的影响。结果表明,抗蒸腾剂具有提高砂生槐抗旱性的作用,其中400倍稀释抗蒸腾剂溶液处理可以提高叶片的叶绿素含量,明显的降低脯氨酸含量的增加幅度,从而增强砂生槐的抗旱能力。     

10种国产玉兰属植物挥发油成分及系统学意义

对10种国产木兰科玉兰属(原木兰属玉兰亚属)植物辛夷挥发油成分及其含率进行分析和研究，其中腋花玉兰、河南玉兰、椭圆叶玉兰、舞钢玉兰、两型玉兰、罗田玉兰和鸡公玉兰7种植物为首次测定。结果表明，10种植物共检测出84种成分，每种植物为36～56种成分，鉴定出62种化合物，其含率占挥发油的98．4％。有17种成分为10种植物所共有，含率达72．9％，以单萜类化合物为主，占64.8％，其余为倍半萜类化合物，占8．1％。主要共有成分为桉油醇、香桧烯、β-蒎烯、月桂烯、α-松油醇，其中桉油醇的含量最高，通常在20％以上，最高达35.5％。5种成分在玉兰属植物挥发油中为首次报道，其中1种共有成分：1羟基-1，7-二甲基-4-异丙基-环癸二烯，其平均含率2.72％；4种非共有成分：α-姜烯、大根香叶烯β、α-倍半水茴香烯和四甲基环癸二烯异丙醇。根据不同植物挥发油成分及其含率差异，提出河南玉兰与椭圆叶玉兰的亲缘关系较近，可能为同一杂种起源。玉兰属挥发油成分月桂烯与四甲基环癸二烯异丙醇具有重要的分类学意义，据此可把10种玉兰属植物分为2类，一类为朱砂玉兰、玉兰、舞钢玉兰、两型玉兰、罗田玉兰和鸡公玉兰，其月桂烯含率在6．0％以上，四甲基环癸二烯异丙醇含率在1％以上；另一类为望春玉兰、腋花玉兰、河南玉兰和椭圆叶玉兰，其月桂烯含率在2．0％以下，不含四甲基环癸二烯异丙醇。     

广东省南水湖湿地维管植物区系研究

2014-2015年,采用线路调查法和样方调查法,对广东省乳源南水湖湿地维管植物进行调查。结果显示,该湿地有维管植物187种,隶属于67科122属;以草本植物为主;湿生植物比例最大。优势科是莎草科Cyperaceae、禾本科Poaceae、水龙骨科Polypodiaceae等,优势属是莎草属Cyperus、凤尾蕨属Pteris、蓼属Polygonum等。南水湖湿地维管植物表征科的地理成分有6个分布型1个变型,热带成分占83.33%;维管植物属的地理成分包括13个分布型7个变型,以热带成分为主体。与其他高纬度地区及同纬度的内陆地区相比,南水湖湿地表现出更强的热带性质;不同地区植物区系聚类分析表明,植物属区系地理成分变化趋势跟地理位置和纬度有关。     

湘西南两江流域支流分流山地区维管束植物区系研究

采用线路和标准地调查,对湘西南长江、珠江流域(两江流域)支流分流山地区的维管束植物进行分析研究,结果表明:①有野生维管束植物241科983属2638种,科、属、种数明显大于邻近同纬度和相近纬度地区,较大类群出现于蕨类植物和被子植物,特别是双子叶植物;②872个种子植物属分布于14个分布型27个变型中,R/T值为1.31,明显大于邻近同纬度区和相近纬度区;③有单种属59属,寡种属165属,单种属特有成分占35.59%,寡种属以14型、7型、9型、8型占优势;④珠江支流浔水区黔桂、华南植物区成分为其重要组成成分,有黔桂、华南典型成分为优势种的植物群落,沟谷分布有沟谷雨林,以板根、茎花、大型叶、复叶增多为其外貌特征,在长江支流渠水区这些黔桂、华南成分不见或少见,其群落和其外貌特征不出现;⑤分水岭牛皮界至传素山及其延伸区是通道境内华中区与黔桂区植物区的分界线。     

大熊猫野化培训圈森林植物群落多样性研究

本文应用植物群落学理论分析了卧龙大熊猫野化培训圈的植物种类组成、区系地理成分、优势树种以及生活型谱等特征。结果表明：大熊猫野化培训圈主要为野核桃、红肤杨、华西枫杨、连香树、扇叶槭、五裂槭、大翅色木槭、长序稠李、槐树等树种组成的落叶阔叶林。栖息地群落中分布的常见种子植物有71种,分属39科,58属,其中裸子植物3种,双子叶植物63种,单子叶植物5种;且以槭树科、杜鹃花科、忍冬科、蔷薇科、竹亚科、虎耳草科、菊科、百合科、禾本科等科植物构成优势组分。占组成植物总数的40．8％以上。从植物地理成分分析来看,无论是科分布型,还是属分布型,大熊猫栖息地植物都以温带分布类型为主,分别占57．5％和46．55％。植物群落生活型谱中以高位茅植物占优势,达56．34％,反映出大熊猫野化培训圈的植物群落具有温带落叶阔叶林特点,这与卧龙大熊猫栖息地的植物群落的生态特征相似。根据植物群落分类原则,将野化培训圈的植物群落共划分为连香树-拐棍竹-黑鳞耳蕨群落、野核桃-短锥玉山竹群落、野核桃-拐棍竹-艾蒿群落和野核桃-薄叶鼠李-小鳞苔草群落等4个类型。     

塞罕坝自然保护区百合科植物资源调查统计与区系分析

2013-2014年,通过样线调查和样地调查相结合的方法,对塞罕坝自然保护区内的百合科(Liliaceae)植物资源种类进行了调查与统计,并对百合科植物区系组成及其特点进行了研究。结果表明:塞罕坝自然保护区野生百合科植物共10属19种。百合科植物属的地理成分以温带区系成分占绝对优势,占总属数的60%,占总种数的73.68%.     

黄平朱家山自然保护区种子植物区系分析

黄平朱家山自然保护区种子植物计145科448属812种(种级单位包括亚种、变种和变型,农作物除外),其中木本植物105科266属539种、草本植物68科201属273种,裸子植物6科7属8种、被子植物139科441属804种。植物科区系为温带-热带分布型,植物属区系为热带-温带分布型。植物区系为华中植物省西部,保留了许多古老成分并具有东亚植物区系的特有性。钙生种子植物区系占相当比例。在岩溶槽谷区的种子植物区系上具有一定代表性并可为石漠化综合治理提供树种选择依据。     

Efficacy of six antitranspirants on black spruce container seedlings

The antitranspirants Plantco, Cloudcover, Vapor Gard and Dow X2-1337 were effective in reducing water loss from black spruce container seedlings. Clearspray and Folicote were unable to reduce moisture loss. Toxicity symptoms and abnormal bud flushing were evident in Vapor Gard treated seedlings. Surfactants failed to increase the effectiveness of Vapor Gard at lower, non-toxic concentrations.     

间伐对库区生态公益林养分流失的影响

以福建永安安砂库区生态公益林为研究对象,通过设置径流小区法,分别在坡度25°和32°的林地中,设计不间伐、间伐强度20%、40%、60%4种处理,研究不同间伐强度对安砂库区生态公益林养分流失的影响。结果表明:林地坡度25°情况下,在养分月流失量及流失总量上,间伐强度60%、40%均明显大于不间伐处理,而间伐强度20%与不间伐处理间差异并不明显,且流失量较少。林地坡度32°条件下,养分的月流失量及流失总量总体上随着间伐强度的加大而增加。此外,同一间伐强度下,养分流失总量随着坡度的增加而增加。可见,对库区生态公益林进行抚育间伐时,选择坡度较缓的林地进行低强度间伐(间伐强度20%)较为合理,能够在很好地发挥生态公益林的生态效益的同时获得一定的经济效益,进而实现库区生态公益林的可持续经营。     

施肥对红松容器苗生长的影响

对基质配方为60%草炭土+30%腐殖土的红松容器苗进行了施肥试验,结果表明,对红松容器苗喷洒的营养元素种类不同,苗木的高、径生长量具有明显差异,其中"全喷"和"缺镁"两种处理的苗木高、径生长量最大。说明基质中除镁以外,其他营养元素均需要补充。     

包头市昆都仑区园林绿地防灾避险服务半径分析

包头市昆区园林绿地服务半径为500m时,缓冲区人口密度为47.5m2/人,服务盲区人口密度为18.7m2/人;服务半径为2000m时,缓冲区人口密度为46.9 m2/人,服务盲区面积人口密度为12.5 m2/人。昆区园林绿地以500m服务半径分析得出的服务盲区高达1/3,以2000m的服务半径分析得出的服务盲区为17%,说明服务盲区所占比例较高。昆区可作为中心防灾的公园只有植物园一处,作为固定避难的公园,只有3处,还远达不到防灾要求,今后应加大一些面积较大的公园绿地建设。       

Influence of temperature and leaf-to-air vapor pressure deficit on net photosynthesis and stomatal conductance in red spruce (Picea rubens)

The roles of temperature (T) and leaf-to-air vapor pressure deficit (VPD) in regulating net photosynthesis (A(net)) and stomatal conductance (G(s)) of red spruce (Picea rubens Sarg.) were investigated in a field study and in a controlled environment experiment. Both A(net) and G(s) exhibited a relatively flat response to temperatures between 16 and 32 degrees C. Temperatures between 32 and 36 degrees C markedly decreased both A(net) and G(s). Vapor pressure deficits above 2 kPa had significant effects on both A(net) and G(s). The influence of VPD on A(net) and G(s) fit a linear response model and did not interact significantly with T effects.     

福建永春油杉天然林群落结构及物种多样性研究

在对福建永春油杉天然林群落系统调查的基础上,对该群落的植物区系成分、结构特征和物种多样性进行了研究.结果表明：该群落共有维管束植物131种,隶属于60科111属 .包括藤本植物在内的高位芽植物占总数的71.75%,区系组成以泛热带成分较高 ,群落结构较为复杂.物种多样性指数（Shannon-Wiener指数）以草本层最高,为2.245 1.     

Finite element analysis of stress and strain distributions in mortise and loose tenon furniture joints

We studied the effect of loose tenon dimensions on stress and strain distributions in T-shaped mortise and loose tenon （M＆amp;LT） furni-ture joints under uniaxial bending loads, and determined the effects of loose tenon length （30, 45, 60, and 90 mm） and loose tenon thickness （6 and 8 mm） on bending moment capacity of M＆amp;LT joints constructed with polyvinyl acetate （PVAc） adhesive. Stress and strain distributions in joint elements were then estimated for each joint using ANSYS finite element （FE） software. The bending moment capacity of joints increased significantly with thickness and length of the tenon. Based on the FE analysis results, under uniaxial bending, the highest shear stress values were obtained in the middle parts of the tenon, while the highest shear elastic strain values were estimated in glue lines between the tenon sur-faces and walls of the mortise. Shear stress and shear elastic strain values in joint elements generally increased with tenon dimensions and corre-sponding bending moment capacities. There was consistency between predicted maximum shear stress values and failure modes of the joints.     

A new boron impregnation technique of wood by vapor boron of boric acid to reduce leaching boron from wood

This study was designed to reveal impregnation ability and to enhance leaching resistance of boron from borate-treated wood. Vapor boron treatment was applied in compressed and uncompressed states at high temperatures such as 180 and 200°C for 6, 8 and 15 min. Following ten-cycle leaching periods, amounts of boron leached from vapor boron treated wood was measured by ion chromatography. According to the results, boric acid can be vaporized under heat and can be impregnated into wood. Success of the technique can be increased by increasing vapor pressure in a closed chamber. Leachability results proved the boron vaporization along with water vapor at various ratios depends on the process variables. These results have importance on dry wood treatment under heat by boron vapor with a little water presence which does not necessitate a further drying process.     

Review on Nutritive Value of Edible Insects

As an importam bio-resource, insect resources have not been put into full play as healthy food. Based on study and analysis, the nutritive value of edible insects was reviewed. The results showed that insects have rich protein (20%-70%), amino acid (30%-60%),fat (10%-50%),fatty acid, carbonhydrate (2%-10%), mineral elements, vitamins and other activated elements which are good for human 's health. As protein resources, the nutritive value of edible insects is as good as animal and plant resources. Insects have feature of rich species and large population, therefore as nutritive resources, edible insects can befully used and have great development potentiality.     

Water sorption mechanisms of commercial wood adhesive films

As water moves inside the wood, the gluelines might act as barriers that are potentially leading to local moistening. Even low amounts of water may influence the mechanical performance of glued wood products. Dynamic vapor sorption analysis was performed to assess the sorption processes of six commercial wood adhesives. Vapor sorption isotherms were compared with vapor uptake dynamics. Phenol–resorcinol–formaldehyde showed high moisture uptake of 18 %, while vapor diffusion speed was low. Fish glue showed a water uptake of 45 % at otherwise moderate vapor uptake speed. Melamine–formaldehyde resin gained 22 % water, and polyvinyl acetate absorbed 10 %. The latter was also the fastest vapor absorbing adhesive. Polyurethane only absorbed 3.5 % of moisture at medium uptake speed. Mechanisms of water diffusion seem to be driven by (1) the available free volume in the polymer and (2) the interacting ionic groups of the polymer chain. While the free volume could be linked to the accumulated moisture, the ionic group interaction might determine the measured vapor diffusion dynamics.