松材线虫病致死松树上的松褐天牛季节性分布规律

连续两年定期监测，调查采样和鉴定证明：每年６－１０月出现的松材线虫师Ｂｕｒｓａｐｈｅｌｅｎｃｈｕｓ ｘｙｌｏｐｈｉｌｕｓ致死松树上、松褐天牛Ｍｏｎｏｃｈａｍｕｓ ａｌｔｅｒｎａｔｕｓ虫株率为１００％，而１１月至次年５月间出现的病死株上，虫株率为零。对前者应集中砍除，并加以严格的除害处理，后者可经剥皮处理后在疫情发生区内加工利用，部分可留在林间作为天牛产卵我饵木。     

双斑锦天牛生物学特性观察

双斑锦天牛ＡｃａｌｏｌｅｐｔｅｓｕｂｌｕｓｃａＴｈｏｍｓｏｎ在山东省一年发生１代，以幼虫越冬。该虫危害冬青卫矛ＥｕｏｎｙｍｕｓｊａｐｏｍｃｕｓＬｉｎｎｅａｕｓ，成虫羽化盛期为６月上中旬，主要天敌为管氏肿腿蜂等，寄生率为２０％左右。对双斑锦天牛的防治可在幼虫期根施３％涕灭威或３％呋喃丹颗粒剂，也可在成虫期于根际喷洒４０％久效磷乳油８００倍液，均能取得较理想的防治效果。     

双斑锦天牛生物学特性观察

双斑锦天牛Ａｃａａｌｏｌｅｐｔｅ ｓｕｂｌｕｓｃａ Ｔｈｏｍｓｏｎ在山东省一年发生１代，以幼虫冬。核虫危害冬青卫矛Ｅｕｏｎｙｍｕｓ ｊａｐｏｍｃｕｓ Ｌｉｎｎｅａｕｓ，成虫羽化盛期为６月上中旬，主要天敌为管氏肿腿蜂等，寄生率为２０％左右。对双斑锦天牛的防治可在幼虫期根施３％涕灭威或３％呋喃丹颗粒剂，也可在成虫期于根际喷洒４０％久效磷乳油８００倍液，均能取得较理想的防治效果。     

两种杨树天牛综合防治和监测技术研究及其应用

在深入研究光肩星天牛ＡｎｏｐｌｏｐｈｏｒａｇｌａｂｒｉｐｅｎｎｉｓＭｏｔｓｃｈｕｌｓｋｙ与桑天牛ＡｐｒｉｏｎａｇｅｒｍａｒｉＨｏｐｅ的生物学、生态学和总结前人研究的基础上，应用以林业措施为主、辅以其他防治手段的综合防治技术，将８００ｈｍ２试验示范区内两种天牛的虫株率持续控制在３％以下。研究和应用简便易行的监测方法对这两种天牛的成、幼虫种群动态进行监测，取得了良好的效果。     

桑天牛辐射不育的研究

桑天牛ＡｐｒｉｏｎａｇｅｒｍａｒｉＨｏｐｅ成虫出现盛期６月下旬７月初，雌雄比为１：１．３，多次交尾，交尾前期４～６ｄ孵化率在６４％以上，６０Ｃｏγ辐照对雄虫寿命及交尾的影响没有不可育率的影响显著，经４．９０２ｃ／ｋｇ（准）处理的饲养雄虫，寿命及交尾变化不大，可育率却明显降低，仅为９％且无活幼虫。     

大造桥虫危害水杉

大造桥虫危害水杉１９９０年９月，湖北省仙桃市赵西垸林场发现大造桥虫ＡｓｃｏｔｉｓｓｅｌｅｎａｒｉａＳｃｈｉｆｅｒｍｉｌｅｒｅｔＤｅｎｉｓ暴发危害，发生面积约１００ｈｍ２，有虫株率达１００％。大造桥虫原为棉花主要害虫，近年发现为害林木，主害水杉。该虫一...     

双斑锦天牛生物学特性观察

双斑锦天牛ＡｃａｌｏｌｅｐｔｅＳｕｂｌｕｓｃａ对园林绿化树大叶黄杨构成严重危害。该虫一年发生１代，以幼虫在寄主枝条内越冬，７月上旬至１１月上旬、３月至５月为幼虫危害期     

生石灰处理松树伐桩防治松褐天牛试验初报

用生石灰处理伐桩,预防和杀灭松褐天牛Monochamus alternatus Hope卵、幼虫.在处理区天牛有虫株率仅2.5%,对照区有虫株率82.6%.     

印楝提取物防治桑天牛的林间试验

以桑天牛成虫Apriona germari Hope喜食的构树为引诱树6株，选取一块与周围树林相对孤立的杨树林为试验地，试验地面积约为0．13hm^2，设引诱树6株，胸径8～10cm。每年1次将2g含30％印楝素的印楝种核提取物配成制剂，注入构树中，进行防治桑天牛林间试验。结果表明：注药前，对照虫株率(57．50％)与处理虫株率(56．41％)之间差异不显著。注药1a后处理林的虫株率下降至38．46％，对照林的虫株率增加到70．00％；2a后，处理林的虫株率下降到23．08％，对照林的虫株率达82．50％。讨论了应用天然化合物防治林木害虫的优点和前景。     

天牛长尾啮小蜂的初步研究

天牛长尾啮小蜂ＡｐｒｏｓｔｏｃｅｔｕｓｆｕｋｕｔａｉＭｉｗａｅｔＳｏｎａｎ是星天牛Ａｎｏｐｌｏｐｈｏｒａｃｈｉｎｅｎｓｉｓ（Ｆｏｒｓｔｅｒ）、桑天牛ＡｐｒｉｏｎａｇｅｒｍａｎｉＨｏｐｅ的卵寄生蜂。在福建省沿海木麻黄林中对星天牛卵寄生率为７．５％－５８．７％,福建省惠安１年３－４代,以老熟幼虫越冬。越冬代成虫在５月旬开始出现。该文对其形态特征进行了描述,对生活史,活习性等进行观察观察。     

兴安落叶松过伐林枯立木分布格局特征分析

以内蒙古根河林业局潮查林场境内的在20世纪80年代初主伐利用后形成的兴安落叶松过伐林为研究对象,利用兴安落叶松林8块标准地每木定位数据,分析林木分布格局和样方(5 m×5 m)林木株数对枯立木株数影响,探讨了林分大树和更新幼树位置与枯立木位置的关系,阐明了枯立木分布格局形成机制。结果表明:1)各树种枯立木比例,随树种组成成数增加而增大。枯立木主要在更新幼树阶段形成,径级分布集中在4径阶以下,其株数占总数的比例平均达82.2%。在更新幼树(含枯立木)中,生成枯立木的比例平均达8.8%。2)枯立木分布格局为聚集分布。林木分布格局、样方林木株数和更新株数与枯立木株数有显著正相关关系,林木分布格局对枯立木分布格局无显著影响。林木聚集度越大,形成枯立木的可能性越大,数量也就越多。3)枯立木位置与更新幼树和大树位置有显著相关关系。主要表现为落叶松和白桦相互关系。枯立木出现位置主要在大树和更新幼树集聚区域。大树对枯立木形成影响较更新幼树大,而且均以落叶松较白桦明显。白桦更新幼树对落叶松枯立木的形成,无显著影响。受影响的枯立木主要是枯立木株数中所占比例和树种组成成数较高的树种。影响枯立木位置的林木主要取决于其样方内位置和林木株数。     

Advance Regeneration in the Inland West

Advance conifer regeneration readily survives release from overstory competition in the Inland West, but foresters are concerned about the ability of released trees to attain normal growth rates. There are also concerns about forest health issues associated with managing advance regeneration. The best pre-release predictors of post-release growth response are pre-release vigor and crown ratio at release. The fastest growing trees before release grow the fastest following release. A general recommendation is that at least a 0.50 crown ratio at release is necessary for good response to release. A 0.50 crown ratio means that trees will have the necessary photosynthetic capability to respond to changes in stand conditions. The best time to release advance regeneration is after budset in the fall but before budbust in the spring. Release during this time period means needles that develop the first summer after release will be adapted to full sunlight. A conceptual framework of physiological response to release is presented.     

Gender, neighboring competition and habitat effects on the stem growth in dioecious Fraxinus mandshurica trees in a northern temperate forest

? This study analyses the sex ratios, and the effect of gender, neighboring competition and habitat factors on the stem growth of dioecious F. mandshurica trees in the Changbai Mountains of North-Eastern China.

? The general sex ratio of the flowering trees did not significantly deviate from 1:1. The sex ratio varied among age classes. A female-biased sex ratio was found in the age classes of 65–75 years and 85–95 years, but departure from 1:1 was not significant in other age classes.

? An analysis of variance revealed that the growth rate was extremely sensitive to gender and tree size, as shown by a highly significant gender-related and size-dependent effect. Male trees had a faster stem growth rate than female trees, and the assumption is that trade-offs between reproductive and vegetative processes can induce the difference in stem growth rate between genders.

? Stem growth rates are positively affected by soil moisture and tree size for both genders at all considered neighborhood distances. The growth rates of female trees were negatively affected by neighboring competition from other female trees at all neighborhood distances between 1 and 10 m, but were not significantly affected by male trees. The growth rates of male trees were negatively affected by neighboring competition from male trees for neighborhood distances between 3 and 10 m, but were not significantly affected by female trees.

? These results suggest that intrasexual competition (male-male competition and female-female competition) may cause difference in stem growth for both genders. Intersexual differences in sensitivity to neighboring plants are considered to be an important factor driving gender-specific growth patterns.

     

Mobile carbohydrates in Himalayan treeline trees I. Evidence for carbon gain limitation but not for growth limitation

To test whether the altitudinal distribution of trees is determined by a carbon shortage or an insufficient sugar fraction (sugar:starch ratio) in treeline trees, we studied the status of nonstructural carbohydrates (NSC) and their components (total soluble sugars and starch) in Abies fabri (Mast.) Craib and Picea balfouriana var. hirtella Rehd. et Wils. trees along three elevational gradients, ranging from lower elevations to the alpine treeline, on the eastern edge of the Tibetan Plateau. For comparison, we investigated a low-altitude species (Tsuga yunnanensis (Franch.) Pritz.) which served as a warm-climate reference because it is distributed in closed montane forests below 3100 m a.s.l. in the study area. The carbon status of T. yunnanensis responded to altitude differently from that of the treeline species. At the species level, total NSC was not consistently more abundant in treeline trees than in trees of the same species growing at lower elevations. Thus there was no consistent evidence for carbon limitation of growth in treeline trees. For the three treeline species studied (P. balfouriana and A. fabri in the Kang-Ding Valley and A. fabri in the Mo-Xi Valley), winter NSC concentrations in treeline trees were significantly lower than in lower-elevation trees of the same species, suggesting that, in winter, carbon is limited in treeline trees. However, in no case was there total overwinter depletion of NSC or its components in treeline trees. Treeline and low-altitude species had similar sugar:starch ratios of about three at their upper-elevational limits in April. We conclude that survival and growth of trees at the elevational or latitudinal climate limit depend not only on NSC concentration in perennial tissues, but also on the maintenance of an overwintering sugar:starch ratio greater than three.     

东风橡胶分公司橡胶芽接树新割制生产情况调查

通过对橡胶树割胶树位调查,低于20割龄胶树实施新割制,一般表现干胶产量增产和年度间产量变化平稳,累计死皮病率低,而高于20割龄胶树实行新割制、老龄割制和强割制,虽然提高刺激剂使用浓度,仍不能表现干胶增产,同时4～5级死皮率明显增高;品系GT1表现比RRIM更耐刺激,增产幅度大,死皮率更低。     

行道绿化树种选择及其栽培管理中的经济学原则

相对于其它城市森林类型,行道树的功能突出,而其生长环境却最为恶劣。在相同的立地条件和相近的抚育管理条件下,行道树树种的选择与栽培管理对街道绿化、美化的景观效果以及行道树体系在减少地表径流、改善小环境气候、净化空气、节能降耗、房地产增值等方面的社会、生态与经济综合效益的发挥起着决定性作用。行道树树种的选择除了要遵循景观规划中的美学原则和适地适树的生态学原则之外,栽培管理方便、综合效益高、经营管理效益成本比值大的经济学原则,也应该成为行道树树种规划选择和栽培管理的重要原则。     

Modelling functional trait acclimation for trees of different height in a forest light gradient: emergent patterns driven by carbon gain maximization

Forest trees show large changes in functional traits as they develop from a sapling in the shaded understorey to an adult in the light-exposed canopy. The adaptive function of such changes remains poorly understood. The carbon gain hypothesis suggests that these changes should be adaptive (acclimation) and that they serve to maximize net vegetative or reproductive growth. We explore the carbon gain hypothesis using a mechanistic model that combines an above-ground plant structure, a biochemical photosynthesis model and a biophysical stomatal conductance model. Our simulations show how forest trees that maximize their carbon gain increase their total leaf area, sapwood area and leaf photosynthetic capacity with tree height and light intensity. In turn, they show how forest trees increased crown stomatal conductance and transpiration, and how the carbon budget was affected. These responses in functional traits to tree height (and light availability) largely differed from the responses exhibited by exposed trees. Forest and exposed trees nevertheless shared a number of emergent patterns: they showed a similar decrease in the average leaf water potential and intercellular CO(2) concentration with tree height, and kept almost constant values for the ratio of light absorption to electron transport capacity, the ratio of photosynthetic capacity to water supply capacity, and nitrogen partitioning between electron transport and carboxylation. While most of the predicted qualitative responses in individual traits are consistent with field or lab observations, the empirical support for capacity balances is scarce. We conclude that modelling functional trait optimization and carbon gain maximization from underlying physiological processes and trade-offs generates a set of predictions for functional trait acclimation and maintenance of capacity balances of trees of different height in a forest light gradient, but actual tests of the predicted patterns are still scarce.     

Phenotypic variation of baobab (<Emphasis Type="Italic">Adansonia digitata</Emphasis> L.) fruit traits in Mali

We analyzed the phenotypic variation of baobab (Adansonia digitata L.) fruits from Mali to define the domestication potential of this species. 269 trees, selected from 10 provenances distributed along a rainfall gradient, were characterized. Five fruits were sampled from each tree. Total individual fruit weight was partitioned into shell, pulp, and seed weight. Ratios were calculated between pulp + seed and total weight, and between pulp and seed weight. For all the measured fruit traits, we detected significant differences between provenances, as well as between trees from the same provenance. Assuming that the measured traits are under genetic control, the latter facts indicate that there are considerable opportunities for tree selection on a local scale. However, candidate plus trees with specific properties, e.g., extremely high pulp or seed weight, were found only in some locations. Mean pulp yield per fruit might be considerably increased by selecting the 5% trees with the highest pulp weight (mean: 45 ± 1 g, best 5%: >100 g). The same might be true for seed production (mean: 71 ± 2 g, best 5%: >150 g). Also the ratio between pulp and seed weight can be an important fruit characteristic for selection: in fruits with a low ratio, relatively more pulp sticks to the seeds when separating the two fruit parts by grinding, and thus more pulp will be lost for further processing. We identified several trees with a high pulp weight combined with a high ratio between pulp and seed weight. It is concluded that there is considerable phenotypic variability in traits of baobab fruit in Mali, offering opportunities for cultivar selection.     

北京栓皮栎林分的干形质量初步研究

探讨了划分林木干形质量的标准,将林木干形质量分为通直、轻度弯曲、二杈分枝、多杈分枝和重度弯曲5类干形。选择了胸径、树高、冠幅、冠长等6个因子,并研究了这6个调查因子随干形质量变化的关系。通过方差分析发现不同干形质量的林木胸径差异并不明显,而其它的调查因子却因干形不同而表现出显著差异。对表现显著的林分因子进行多重比较研究,发现通直干形生长得较高、有较小的冠径比;二杈分枝和多杈分枝林木的冠幅较大,且二杈分枝类型林木的高径比最小。可以得出结论:在近自然经营过程中,在选择以材质为目的的目标树时,首先考虑干形通直的林木。     

Growth and survival of termite-piped Eucalyptus tetrodonta and E. miniata in northern Australia: Implications for harvest of trees for didgeridoos

The most common canopy trees in the savannas of northern Australia, Eucalyptus tetrodonta and E. miniata are also two of the most common species harvested to make didgeridoos, the traditional musical instrument of northern Australian Aboriginal peoples now experiencing high demand from international markets. Most of the trees of the area naturally have hollow cores, or pipes, due to termite activity, but little is known of the relationships of the cores to size of tree, tree growth or survival. In a wooded savanna of northern Australia, 267 individual trees with known growth and survival rates were cored to determine degree of termite-piping. Generalized linear modelling and multi-model inference showed that frequency of piping increased with diameter (dbh) tree for E. tetrodonta, but >85% of E. miniata trees were piped regardless of dbh. Growth (dbh increment) and survival (4-year) were size-dependent. Survival of both species decreased strongly with degree of piping (pipe ratio). For any given diameter, the growth rate of E. miniata trees was independent of pipe ratio, but for E. tetrodonta trees decreased strongly with pipe ratio. From modelled data, a 10-cm tree with pipe ratio of 0.60 was very vulnerable, growing at 0.0 cm year⁻¹ with 46% survival rate, whereas a 40-cm tree, even with large pipe ratios (0.80), grew 0.05 cm year⁻¹ with 98% survival rate. Traditional methods of tree harvesting remove only those smaller hollow trees that are already suffering low growth rates and are likely to die before reaching maturity, whereas current large-scale commercial methods also remove trees with higher growth and survival rates—those trees most likely to contribute to sustainable tree populations. Incorporating traditional selection and harvest methods into current commercial operations would help ensure longevity of this source of livelihood for indigenous peoples of the region.