树木单宁含量可作为对两种星天牛的抗性指标

对８７种常见造林绿化树种的主干树皮，嫩枝和树地的单宁含量进行了测定，并和两种星天牛这些部位相应的刻槽产卵，取食量进行了对比分析。结果表明，抗性树种具有较高单宁含量，而单宁含量较低的树种中有８０％是感虫树种，其余的大多为含有特殊成分的药用树种。     

榧树种子层积过程中主要贮藏物质含量及酶活性的变化

对2013年10月采自浙江省嵊州市榧树(Torreya grandis)种子当年进行层积催芽,通过测定种子胚乳淀粉、可溶性糖、蛋白质和脂肪含量以及与贮藏物质相关酶类中的淀粉酶、蛋白酶和酸性磷酸酯酶的活性变化,研究其主要贮藏物质和相关酶类的变化规律。结果表明:榧树种子层积150 d后,淀粉含量减少40.30%,蛋白质含量减少57.78%,粗脂肪含量减少22.45%;可溶性糖含量呈先降低后升高;淀粉酶、蛋白酶、酸性磷酸酶活性在层积处理0~120 d时逐渐升高,120~150d时略有降低。这说明榧树种子在层积处理过程中,主要贮藏物质在相关酶类的催化下逐渐分解,为种胚的发育和种子萌发提供能量和物质基础。     

浙江主栽板栗营养物质的品种和地域差异分析

本文分析了浙江省４个品种、７个产地共１１个板栗样品的含水量、还原糖、脂肪、蛋白质、氨基酸组分和含量以及支、直链淀粉含量与淀粉粒形状、直径等,在所测定的指标中,蛋白质含量与氨基酸含量、脂肪含量与还原糖含量、支链淀粉与直链淀粉含量呈较显著正相关,而含水量与蛋白质、氨基酸、批肪与支、直链淀粉、还原糖、支链淀粉含量呈较显著负相关。     

锥栗栽培品种果实营养成分差异的分析

本文分析了福建省建瓯市15个锥栗品种样品的淀粉、还原糖、总糖、脂肪和蛋白质的含量，并对淀粉、糖分进行了单因素方差分析，发现品种不同对糖分、淀粉含量均有显著影响。锥栗含有丰富的淀粉、蛋白质、糖分，不同品种间其含量有较大的差异，以乌壳长芒、嫁接毛榛、大尖嘴的含量最高，其蛋白质、总糖含量分别在6.64%和11.48%以上。     

不同种皮色木豆蛋白质淀粉含量的研究

对云南省 8个栽培地、10个种皮色的木豆籽实进行蛋白质及淀粉含量分析测定 ,结果表明 :蛋白质、淀粉含量均与栽培地、种皮色和栽培地×种皮色互作呈极显著差异。不同栽培地的蛋白质、淀粉含量分别为 2 0 .73%～ 2 4 .86 %和 4 8.2 3%～ 54 .2 2 % ;不同种皮色的蛋白质、淀粉含量分别为 2 0 .96 %～ 2 3.96 %和50 .0 2 %～ 53.34 % ;除元谋的淀粉含量为第三类以外 ,其余栽培地和种皮色的蛋白质及淀粉含量均为第二类。各栽培地、种皮色间蛋白质、淀粉含量有一定差异 ,但从总体看 ,仍缺乏高蛋白、高淀粉含量类型。     

湖南省板栗品种和栽培經驗的調查研究

一、前言湖南木本粮食资源丰富,粗略估计约有70多种,而且不论山区、丘陵地区都适宜种植。板栗树是湖南重要粮食树种,营养价值很高。其中淀粉和糖的含量高于小麦和大米,干栗中蛋白质、脂肪的含量高于大米和苞米(详见下表)。     

板栗白蚁防治措施

板栗为木本粮果树，富含淀粉、蛋白质、脂肪及多种维生素和矿物质．可作粮食食用。板栗适应性强，属喜光树种，我国大部分地区有栽植。     

城市绿化树种释放低分子化合物成分分析

对23种城市绿化树种释放出的低分子化合物成分进行了定量测定,根据测定结果,按含有抑菌作用的低分子化合物相对含量大小和含有芳香性质的低分子化合物相对含量的大小对树种进行排序,为不同功能区绿化树种的合理选择和配置提供科学依据。       

柳杉毛虫对不同寄主植物的选择性及适合度

柳杉毛虫可在不同地区为害不同寄主植物并造成生物灾害,通过观测其行为选择与寄主植物内含物成分,分析柳杉毛虫对不同寄主植物的选择性及适合度。以福建地区的柳杉、柏木、侧柏和马尾松为寄主,分别采用笼养法观测成虫产卵量(E),叶碟法观测初孵幼虫的取食选择频次以及取食量(D),并测定不同寄主针叶中主要营养物质(可溶性糖、可溶性蛋白质、淀粉)及植物次生物质(类黄酮、总酚、单宁)含量。结果表明:无论是产卵量,还是取食选择频次与取食量,柳杉毛虫的选择顺序均为柳杉>柏木>侧柏>马尾松,表明该虫对上述的选择具有一致性。4种寄主适合性指数(I_F)分别为0.48(柳杉)、0.39(柏木)、0.09(侧柏)和0(马尾松);进一步关联I_F、E分析发现,针叶中可溶性糖、可溶性蛋白含量均与I_F呈显著正相关(P<0.05),与单宁含量呈显著负相关(P<0.05),表明可溶性蛋白、可溶性糖及单宁含量是柳杉毛虫幼虫优先选择寄主的主要因素。系统聚类可将寄主划分为3类,分别为适宜寄主(柳杉、柏木)、较适宜寄主(侧柏)和不适宜寄主(马尾...     

黄刺蛾幼虫摄食量的初步研究

黄刺蛾是多种园林绿化树种的主要害虫。作者研究了黄刺蛾幼虫在观赏树种红叶李上的摄食习性和摄食量。该虫在湖南衡阳地区为害期为６～７月,幼虫共７龄,平均龄期２８ｄ,末龄９ｄ。每头幼虫一生平均取食红叶李叶片５４．８１９ｍｍ＾２,其中５龄以前取食量为１３６６ｍｍ＾２,仅占整个取食量的２．４％,末龄幼虫取食量为４６４９４ｍｍ＾２,占整个取食量的８４．８％。防治适期为６月上旬。     

过度修枝对油松生长及其抗虫性影响以及合理修枝探讨

油松幼林封山八年后,连续2-3年过度修枝(只留2轮枝)或过度修枝又失叶后,油松的光合强度、蒸腾强度、叶绿素含量及生长量都显著下降,针叶中可溶性糖、淀粉含量下降,脂肪与蛋白质含量反而增高,松毛虫食物的总热量增大,取食其针叶后,赤松毛虫幼虫体重增长率提高。合理修枝不仅能提高油松的光合强度与树势,还能增强抗虫性。研究还发现,油松第四轮枝的一年生针叶量与光合产物量最多,对增强树势与抗虫性极为重要,应予以重点保护,并据此提出了油松合理修枝的指标。     

Analysis of variables influencing tree cork caliper in two consecutive cork extractions using cork growth index modelling

The influence of tree and stand variables, debarking intensity, and precipitation on the caliper of cork produced by a tree and on the evolution of cork caliper between consecutive cork extractions was researched. A total of 370 cork samples were collected in 23 permanent plots distributed across the cork production area in Portugal, covering a period from 1984 to 2010. Cork growth was evaluated using the cork growth index (cgi), defined as the radial width of the first eight complete years of cork growth after stripping. The differences in mean cgi at plot level between two consecutive cork growth periods (cgp) were assessed using nonparametric tests. A mixed model approach was used due to the nested structure of the data for modelling cgi value at tree level. The cgi of two consecutive cork extractions is linearly related at tree level. At plot level, the mean value of cgi decreased in 5 out of the 23 plots and increased in 2 plots for α = 0.05. The number of debarked branches and the variation of precipitation between two cgp were the variables that explained the largest part of the cgi evolution. However, significance of plot random parameters indicates that other variables are involved in the tree cgi evolution, pointing out to the need of further research. Tree size and precipitation during the cgp are related to the individual tree cgi. The effect of increasing stand density and debarking intensity on cork growth was not clear. Long term research based on permanent plot measurements and research trials is needed to clarify the impact of tree competition and debarking intensity.     

Birds like it Corky: the influence of habitat features and management of ‘montados’ in breeding bird communities

In the southwest part of the Iberian Peninsula the dominant land-use are the Portuguese montados and Spanish dehesas, parkland forested areas of anthropogenic origin dominated by cork oak. They form a wooded matrix with open areas, scattered woodlands and undisturbed patches of Mediterranean forest and scrublands. The montados are characterized by a rich bird community. We have focus our study in a multidisciplinary approach, evaluating how management and landscape patterns influence the bird community in order to identify potential threats to its conservation. The study was conducted in the Site of Community Importance of Serra de Monfurado were 70% of the area is cork and holm oaks. We used data from 120 10-min point counts. Using variation partitioning, we determined the independent and joint effects of Forest, Management and Habitat variables. The variation captured in bird assemblage was 65.06%. Most of the explained variation was related to the Habitat and Management variables. The explanatory variables that were high-lighted as important predictors were variables that reflected tree and shrub density and cork removal. Modelling for forest species through generalized linear models (GLM) emphasize that the management plays an important role in the species distribution. The most important variables selected in models reflected cattle grazing and cork removal. Our results point out that the type of management is crucial to maintain the equilibrium in bird community associated to montados. Farmland and forest species will benefit from areas with different tree densities, small patches of Mediterranean scrubs in the understory and correct livestock numbers.     

Growth stresses and strains in cork

Summary A detailed study of the growth stresses and strains in the cork shell of the cork-oak was undertaken based on experimentally determined constitutive relations for cork in tension and compression. The stresses depend on the thicknesses of the cork shell and of the back layer around the cork shell, on the radius of the trunk and on its increase due to growth. The circumferential stresses in the cork shell and back layer are tensile and increase with increasing distance to the tree axis. The radial stresses are compressive and decrease with increasing distance to the tree axis. The strains due to growth are not recovered when the cork boards are removed, unless the boards are heated, for example, by immersion in boiling water. Other consequences of the growth stresses are analysed, such as the occurrence of corrugations in the lateral cell walls of cork, the variation of width of the successive growth rings and the occurrence of cracks in the back layer and outer cork layers.     

Method for evaluation of coarse cork oak root system by means of digital imaging

Digital imaging is becoming a powerful tool for data storage and information retrieval. Image comparison and similarity evaluation has become part of the information market and it is today a common part of, for example, web search engines. The cork oak tree (Quercus suber L.), the dominant species of the ??montado?? woodland system is, due to its cultural and socio-economic value, protected by law that prevents extensive destructive studies on an essential part of the tree??the root. Especially in the Mediterranean zone, where the water is the limiting growth factor, the root development studies are of significant interest. In this work we present a method of using digital images for cork oak coarse root systems-evaluation by means of digital imaging. Acquired images of structural roots are processed automatically to prevent subjective decisions by the human observer. The performance of the method, its potential for semantic retrieval and similarity assessment is demonstrated, having as example eight young cork oak root systems, and critical issues for evaluation and conclusion-making, are discussed.     

Cork weight prediction at tree level

In spite of the importance of cork and cork oak stands in the Portuguese forest and economic scenarios, little research work has been done with this species over the years. The main objective of this study is to define a system of prediction equations to assess air-dried cork weight using dendrometric variables of the tree as predictors. These equations can be used at an intermediate age of the cork production cycle, which is usually of 9 years, or at the year of the stripping process, with 9 years old cork. Several alternative models were developed, from simpler models, using variables easy to gather in the field, to more complex ones that maximise the prediction ability. The development of the weight prediction equations was based on data gathered on three stands located in a region located in the centre/south Portugal, the Coruche county, with average aptitude regarding cork production.     

Chronic cork oak decline and water status: new insights

Chronic decline and Sudden death are two syndromes of cork oak (Quercus suber) dieback. Mortality is associated with water stress, but underlying physiological mechanisms are poorly understood. Here, we investigated the physiological performance of declining trees during the summer drought. Leaf water potential, gas-exchange, fluorescence of photosystem II and leaf and root starch concentration were compared in healthy (asymptomatic) and declining trees. Low annual cork increment in declining trees indicated tree decline for several years. All trees showed similar water status in spring. In summer, declining trees showed lower predawn leaf water potential (?2.0 vs. ?0.8 MPa), but unexpectedly higher midday leaf water potential than healthy trees (?2.8 vs. ?3.3 MPa). The higher midday water potential was linked to by means of strongly reduced stomatal conductance and, consequently, transpiration. This study is pioneer showing that declining trees had high midday water potential. A tendency for lower sap flow driving force (the difference between predawn and midday water potential) in declining trees was also associated with reduced photosynthesis, suggesting that chronic dieback may be associated with low carbon uptake. However, starch in roots and leaves was very low and not correlated to the health status of trees. Declining trees showed lower water-use efficiency and non-photochemical quenching in summer, indicating less resistance to drought. Contrarily to chronic decline, one tree that underwent sudden death presented predawn leaf water potential below the cavitation threshold.     

人工林物种多样性与害虫的控制

根据国内外的最新研究成果,从人工林害虫可持续控制的需求出发,对利用物种多样性与系统稳定性控制虫害的可能性、人工林物种多样性与害虫控制的关系及其内在作用机制、天然林与人工林在抑制虫害能力上的差别进行综述,分析人工林植物物种多样性与昆虫物种多样性对害虫控制的影响,认为植物物种多样性主要从植食性昆虫搜寻寄主植物,植物营养的差异对植食性昆虫取食和发育的影响,及种类组成不同的植物群落中植食性昆虫天敌数量的变化3个方面影响害虫的发生;要通过调节植物群落中昆虫物种的多样性影响目标害虫的种群数量,既要维护其天敌类群的稳定,也要使与害虫处于同一营养层次的其他植食性昆虫有足够的多样性,甚至也要保护和利用中性、中位及顶位昆虫.对人工林害虫的控制,可借鉴天然林自控虫害的原理,采用生态育林、封山育林及生物技术措施,逐步调整林分的结构,提高其物种多样性,增强林分自身的抗虫能力.     

湖南省栎类资源开发利用研究

对湖南省栎类资源的分布特点,开发利用现状,开发利用途径及开发利用策略进行研究。湖南省栎类资源丰富,分布广泛,是本省残存不多的天然阔叶林中的优势种,有很高的经济价值,除传统上作为用材、淀粉资源、鞣料资源外,还可作为薪炭材、利用栓皮、培养菌菇、饲养柞蚕等;同时还具有涵养水源、保持水土、维持生态平衡等诸多极为重要的生态效益。栎类在本省的分布表现出明显的地带性差异和地域性特点,构成相对集中于湘东、湘南、湘西北山地一线,呈“马蹄形”分布的格局。由于常与其他树种混交,资源零星分散,且分布偏远,造成利用困难。对栎类资源的开发利用必须将保护现有栎类资源,发挥生态效益放在首位;对资源丰富的重要商品原料可加大开发力度;对一些有重要经济价值的栎类树种可进行人工驯化栽培。在开发利用模式上,要走立体开发、综合利用,可持续发展的道路,并注重深加工和新产品开发,将栎类资源优势转变为经济优势。