红松人工林幼龄材与成熟材干缩性的比较

对红松人工林幼龄材与成熟材气干与全干时的干缩性能进行了测试和分析。结果表明：幼龄材与成熟材气干与全干时干缩系数相比，幼龄材的径向、弦向、体积干缩系数均大于成熟材；气干与全干时差异干缩都是成熟材小于幼龄材。在木材利用上尽量选择成熟材，以提高产品质量，实现较高的经济价值。     

三峡库区莲峡河小流域马尾松水文生态效应

2004年,在三峡库区莲峡河小流域马尾松林地进行了大气降水、林内透雨、树干茎流的测定,进行了林下枯落物和土壤对降雨影响的研究.结果表明:观测期,马尾松林内透雨占大气降水总量的76.70%,林冠层截留量占降雨总量的23.03%,树干茎流占降雨总量的0.27%;林下枯落物的最大持水量为3.40 mm,林地0～40 cm层土壤饱和蓄水量为183.60 mm;林内透雨、树干茎流、林冠截流与大气降水量以及降雨强度具有显著的二元线性相关关系.     

黔中地区马尾松杜鹃群落杜鹃根围真菌多样性

选取黔中地区的贵阳市乌当区百宜乡(WD)、花溪区孟关(MG)和贵州省黔南龙里县龙架山森林公园(LL)3个地区的马尾松-杜鹃群落为研究对象,采集杜鹃根围土壤进行高通量测序,分析物种多样性,并通过数量生态学原理分析植物群落物种α多样性及土壤养分对真菌群落的影响.结果表明:从杜鹃的根围土壤中获得有效序列505 444条,隶属于9门23纲84目169科296属真菌(3 435 OTU),其中LL有真菌9门19纲53目90科127属(495 OTU)、 WD有8门21纲78目150科246属(1 076 OTU)、 MG有6门17纲55目99科129属(522 OTU).菌群α多样性分析显示, Chao1,ACE,Shannon指数均表现为WD大于MG和LL.菌群群落结构受生境植物多样性、土壤养分的综合作用,土壤有机质、 pH值以及速效磷、速效氮、全氮含量较大程度解释了真菌对土壤养分变化的响应.     

寄主树木、寄主和环境因子对松褐天牛深沟茧蜂寄生率的影响研究

[目的]松材线虫病是我国对森林危害和威胁最严重的病害,控制其传播媒介昆虫松褐天牛是防治松材线虫病的主要手段。作者发现的松褐天牛深沟茧蜂(Iphiaulax monochamusi Yang)是寄生松褐天牛中老龄幼虫的重要天敌。为明确松褐天牛深沟茧蜂的寄生率与寄主树木、寄主和环境因子的关系,开展了本研究。[方法]通过解剖46株松褐天牛危害致死的马尾松,调查了松褐天牛深沟茧蜂寄生率与马尾松、松褐天牛和环境因子之间的关系。[结果]调查研究表明:寄主树木的高度、胸径和树龄对松褐天牛深沟茧蜂寄生率没有显著影响,松褐天牛的数量对松褐天牛深沟茧蜂寄生率亦没有显著影响,而松褐天牛幼虫龄期和松褐天牛幼虫在树干上的位置显著影响松褐天牛深沟茧蜂寄生率。松褐天牛深沟茧蜂寄生率与松褐天牛龄期呈显著正相关,其偏好寄生3~5龄幼虫;就天牛在其危害寄主树木上的位置而言,松褐天牛深沟茧蜂偏好寄生马尾松主干上部和在韧皮部危害的松褐天牛幼虫,其对位于马尾松树干上部的寄主幼虫寄生率最高,达27.38%,对在韧皮部生活、危害的寄主幼虫寄生率为20.18%,显著高于位于木质部生活的寄主幼虫寄生率(5.46%)。逐步回归分析表明:影响松褐天牛深沟茧蜂寄生率的关键环境因子是寄主树木的坡位和其它天敌寄生率,其中,坡位与松褐天牛深沟茧蜂呈显著正相关,其它天敌寄生率与松褐天牛深沟茧蜂寄生率呈显著负相关。[结论]以上研究初步明确了松褐天牛深沟茧蜂的寄生率与寄主树木、寄主害虫和天敌之间的关系,为今后利用该重要天敌控制松褐天牛打下了基础。     

Customer adapted grading of Scots pine sawn timber using a multivariate method

To define new grading rules, or to customize the ones in use in a rule-based automatic grading (RBAG) system of boards, is a time-consuming job for a sawmill engineer. This has the effect that changes are rarely made. The objective of this study was to continue the development of a method that replaces the calibration of grading rule settings by a holistic-subjective automatic grading, using multivariate models. The objective was also to investigate if this approach can improve sawmill profitability and at the same time have a satisfied customer. For the study, 323 Scots pine (Pinus sylvestris L.) boards were manually graded according to the preferences of an important customer. That is, a customer that regularly purchases significant volumes of sawn timber. This manual grading was seen as reference grading in this work. The same boards were also scanned and graded by a RBAG system, calibrated for the same customer. Multivariate models for prediction of board grade based on aggregated knot variables, obtained from the scanning, were calibrated using partial least squares regression. The results show that prediction of board grades by the multivariate models were more correct, with respect to the manual grading, than the grading by the RBAG system. The prediction of board grades based on multivariate models resulted in 76–87% of the boards graded correctly, according to the manual grading, while the corresponding number was 63% for the RBAG system.     

次生马尾松林下植被恢复措施的水土保持效益

通过采集江西省赣县花岗岩区次生马尾松纯林地不同植被恢复措施坡面径流小区2010—2011年的降雨产流产沙资料,分析不同模式的水土保持功能及其植被恢复的水土保持效益。结果表明:1)次生马尾松稀疏纯林地水土流失严重,年产流系数为0.50～0.60,侵蚀模数在2 700～6 000 t/(km2.a)之间。2)植被恢复可以降低林地土壤侵蚀强度,但植被恢复的水土保持效益与林冠结构和地表覆盖度密切相关,当形成乔草或乔灌复合层时,可以起到50%～60%的年蓄水效益和65%～70%的年固土效益。3)植被恢复的水土保持效益亦受植被和降雨类型的影响,百喜草蓄水效益随降雨量先增后减,暴雨是蓄水效益变化的转折点,而胡枝子蓄水效益变化规律不一;植被恢复措施固土效益随降雨量的增加而降低,特别是在大暴雨情景时急剧下降。     

云南松与旱冬瓜混交林林地土壤养分及细根、叶片养分特征

为了探讨云南松与旱冬瓜混交对养分的利用情况,对云南松纯林、云南松与旱冬瓜混交林分、旱冬瓜纯林3种林分类型进行了林地土壤及叶片、根系养分质量分数的测定分析.结果表明:云南松与旱冬瓜混交林地土壤表层土的有机质、有效磷、水解氮、有效钾、全氮、全磷、全钾、交换性钙、镁离子等肥力指标都比纯林高,pH值也发生了变化,介于云南松纯林...     

旱冬瓜乙醇乙醚提取液对云南松种子发芽后幼苗生长的化感效应

旱冬瓜是云南松混交林树种之一,为了解旱冬瓜对云南松的化感作用,用旱冬瓜鲜枝、鲜叶、树皮、树根、凋落物乙醇乙醚的提取液对云南松种子进行处理,观察对其发芽后幼苗生长的影响,所用的提取液浓度分别为800、400、150mg/kg。结果表明,高浓度提取液对云南松幼苗的鲜重、胚根长、胚轴长起抑制作用,随着提取液浓度的降低,抑制作用减弱、促进作用加强;鲜枝中所含对幼苗鲜重起促进作用的化感物质比其他器官多;树皮中所含对幼苗鲜重起抑制作用的化感物质比其他器官多,而所含对幼苗胚根长和胚轴长起抑制作用的化感物质比其他器官少;就不同测试指标的敏感性而言,3个测试项目的敏感性顺序是胚根长﹥胚轴长﹥鲜重。营造云南松旱冬瓜混交林时,应适当控制旱冬瓜的比例,以利于云南松幼苗的生长。     

Salt distribution in response to optical stratification porosity and relative windspeed in a coastal forest in Niigata, Japan

Wind velocity, vertical stand structure and seasalt distribution were measured at various heights inside a plantation of coastal pine forest, with thinning and unthinning, to assess whether any relationships exist between the wind profile, stand structure and seasalt distribution in the coastal pine forest. The vertical stand structure, i.e., optical stratification porosity (OSP), which is defined as vertical distribution of the proportion of sky hemisphere not obscured by tree elements inside a forest stand, was determined for each height by computer analysis of digital images taken with a hemispherical lens. The distribution of OSP in the coastal forest follows the Lambert-Beer's law with absorbency coefficient (). The relative windspeed within canopy can be described using the exponential form with the attenuation coefficient (). The sea-salt was collected using salt gauze (a surgical dressing of loosely woven cotton) both inside and outside the coastal forest, and the distribution of sea-salt within canopy was also in accordance with an exponential function. The relationships among windspeed, OSP and sea-salt indicate that the distributions of both sea-salt and windspeed within canopy were very closely correlated with the distribution of OSP. A linear relationship between OSP and sea-salt has been found. Additionally, linear regression between coefficients and has been obtained as well. Based on these relationships between OSP, wind and sea-salt in the coastal forest, the sea-salt distribution and wind profile within the canopy of the coastal forest can be predicted according to OSP. These results may therefore be useful in analyzing the effects of sea-salt on vegetation and evaluating the filter functions of coastal forests.This revised version was published online in November 2005 with corrections to the Cover Date.     

黄龙山白皮松林林隙物种多样性动态

运用Margalef丰富度指数（R）、Shannon-Wiener多样性指数（H′）、Pielou均匀度指数（Js）和生态优势度指数（λ）对黄龙山白皮松林不同大小和不同发育阶段林隙的物种多样性的动态规律进行了研究。结果表明:林隙中草本层、灌木层、乔木层植物的Shannon-Wiener多样性指数在Ⅲ级林隙（400~600 m²）时最大,随着林隙面积的增大,Shannon-Wiener多样性指数呈下降趋势,各生长型多样性指数在林隙发育的中前期（45~90 a）达到最大值,随着林隙年龄的增加而减少;草本层、灌木层和乔木层植物的Margalef丰富度指数和Pielou均匀度指数的变化趋势总体上与Shannon-Wiener多样性指数一致,生态优势度指数与Shannon-Wiener多样性指数几乎相反;乔木层植物的Shannon-Wiener多样性指数随林隙大小和年龄的变化趋势较灌木层和草本层植物变化缓慢,灌木和草本对林隙微生境的时空变化很敏感;R、H′、Js和λ在白皮松林不同大小和不同发育阶段林隙中表现显著性差异。