云南切梢小蠹的室内饲养及隐蔽期生活习性的观察方法

云南切梢小蠹(Tomicus yunnanensis Kirkendall and Faccoli)是云南松(Pinus yunnanensis Franchet)的主要害虫之一[1],该虫于20世纪80年代首次在滇中地区大面积危害,以后蔓延至云南省15个州(市)65个县,迄今已导致6万多公顷云南松林死亡[2-5].2008年以前,该虫曾经长期被认为是纵坑切梢小蠹(Tomicus piniperda L.)[1].与大多数小蠹相似,云南切梢小蠹钻蛀在树皮与边材之间,终生潜伏生活,只有新成虫羽化后的短暂时间飞离树身,在林中活动、觅食、交配,另筑坑道入侵新寄主[6-7].     

麻栎 马尾松天然次生混交林生物量结构及根系分布特征调查研究

通过对马尾松、麻栎天然次生混交林林分生物量的测定,对林分生物量积累、根系分布特征的差异进行了研究。结果表明,两类树种混交造林方式能在一定程度上提高树干的生产量,天然次生麻栎较马尾松具有主根、水平根系均发达,且须根分布均匀的特点。     

微波处理松材线虫病疫木技术研究

该文对利用微波处理松材线虫病疫木技术进行了研究，结果表明：不论木材厚薄大小、含水量多少、在微波处理炉腔内怎样堆放，以及环境温度、微波功率等因素的如何变化，只要SWB-Ⅱ型隧道式微波除害处理设备显示的木材表面温度大于68℃，持续30min，就能有效地杀死松木中的松褐天牛和松材线虫。     

Prediction of pine mistletoe infection using remote sensing imaging: A comparison of the artificial neural network model and logistic regression model

In this study, the prediction of pine mistletoe distribution in Scots pine ecosystems was explored using remote sensing variables to compare the multilayer perceptron (MLP) artificial neural network (ANN) and logistic regression (LR) model performances. For this purpose, 109 sample plots were distinguished in pure Scots pine forests (natural) in the Eastern Black Sea Region of Turkey. Distinguishing mistletoe-infected stands (69) and uninfected stands (40) was performed with field observations. The variables acquired from Landsat 8 (Level 1) images were used as independent variables for independent-sample t-test, MLP ANN and LR models. Remote sensing variables indicated that mistletoe-infected stands were in drier areas with a lower vegetation-leaf area index. Based on the performance results of both models, the sensitivity (SEN), specificity (SPE), positive predictive value (PPV), negative predictive value (NPV) and accuracy of the MLP ANN model were superior to those of the LR model. The prediction percentages (SEN, SPE, PPV and NPV) of mistletoe-infected stands were better than the prediction percentages of uninfected stands. The prediction accuracies of LR and MLP ANN models were 74.3% and 89.6%, respectively. However, all remote sensing variables were included in the prediction equation of the MLP ANN model, while the thermal infrared 1 (TIRS1) variable was included in the LR model. In the MLP ANN model, the TIRS1 variable also had the highest normalized importance (100%). The area under the curve (AUC) value for identifying the mistletoe-infected stands of Scots pine forests used by the MLP ANN model (0.892 ± 0.034) was higher than in the LR model (0.838 ± 0.039), explaining the more accurate predictions obtained from the MLP ANN model. The MLP ANN model showed much better performance than the LR model. The results of this study are expected to make important contributions to the identification of potential mistletoe-infected areas.     

长白落叶松人工林的适宜经营密度

针对目前长白落叶松人工林间伐研究缺乏长期定位资料的状况,对东北东部林区同一立地条件下、同一林龄长白落叶松人工林采取不同密度经营指数(近似0.7、0.8、0.9、1.0、>1.0)进行了间伐,并长期记录其生长状况,研究其间伐的长期效果。结果表明:到达成熟期时,样地内保留木的平均胸径是随着经营密度指数的增大而减小,即间伐强度越大,林木的平均胸径越大。而不同的经营密度指数对单位面积蓄积量的影响没有明显差异。综合研究认为:落叶松人工林适宜采取的经营密度指数为0.7、0.8。     

华西雨屏区人工竹林凋落物及表层土壤的水源涵养功能研究

以华西雨屏区退耕还林后形成的人工竹林(慈竹林、苦竹林、撑绿杂交竹林、苦竹 光皮桦混交林)为对象,对其凋落物及表层土壤的水源涵养功能进行了初步研究。结果表明:几种竹林凋落物蓄积量的大小顺序是:撑绿杂交竹林>混交林>苦竹林>慈竹林,且都大于光皮桦林。叶凋落物持水量的大小关系为:慈竹林>混交林>苦竹林>杂交竹林,光皮桦林的持水量介于慈竹林和混交林之间。几种叶凋落物持水量与浸泡时间的关系符合指数函数的模型、持水速率与浸泡时间的关系符合幂函数的模型。不同林地的表层土壤容重在1.27~1.34 g/cm3之间,总孔隙度48.08%~55.96%,不同林地表层土壤的水分物理性质差异不大。     

马尾松人工林可燃物负荷量和燃损量的动态预测

森林可燃物是森林燃烧的物质基础,是林火行为预报的基本依据之一。基于森林燃烧和蔓延规律,选取地表层、树冠层为建模单元;利用林分因子和火环境因子,通过多元回归分析方法,建立了低山丘陵区马尾松人工林幼龄林及中龄林可燃物类型的可燃物负荷量和可燃物烧损量模型。     

加勒比松不同容器与基质育苗试验

试验结果表明，苗木５个月生时苗高生长，舒根型育苗器〉薄膜育苗袋〉硬塑管育苗器，已充分腐熟的木糠和高质量火烧土是两种优良的加勒比松育苗基质，基质的９种配方，１，２配方芽苗上袋成活率很低，６，７配方苗木生长最好。     

尾叶桉 湿地松1～6年生施肥效应研究

尾叶桉、湿地松１～６年生幼林施肥结果表明：１．尾叶桉在缺Ｐ的立地上,施Ｐ肥的效应极其显著。施Ｐ各处理在１～６年生时均显著或极显著地大于对照,其中以施ＮＰＫ全肥最好,６年生的树高、胸径和材积与对照比较,分别增长３５％,６９％,２４３％。而施ＮＫ肥的生长与对照差别不大。湿地松１～２年生的幼林施肥效果不大显著,３～６年生时才达显著差异,其中以施ＮＰＫ全肥的效果最好,６年生的树高、胸径和材积与对照比较仍分别增长１３％,１８％,５２％。２．尾叶桉、湿地松施Ｐ肥的各水平均达显著或极显著差异,施Ｎ、Ｋ肥的只在个别年度有差异。３．偏相关和复相关分析结果表明,尾叶桉施肥肥效主次顺序是Ｐ、Ｎ、Ｋ,湿地松是Ｐ、Ｋ、Ｎ。两树种均在５,６年生时,Ｎ、Ｐ、Ｋ的肥效最高。４．最优施肥配方：尾叶桉１～３年生以施Ｎ３Ｐ３为好,５～６年生以施Ｎ３Ｐ３Ｋ２为佳。湿地松１～２年生不用施肥,或薄施Ｎ肥;３～６年生以施Ｎ１Ｐ３Ｋ１较好。     

Growth and yield models for uneven-sized forest stands in Finland

Uneven-sized forestry is gradually gaining popularity and acceptability also in the Nordic countries. This is because of the willingness of the public and some forest owners to avoid clear-fellings and pursue more near-nature forest structures. It has also been realized that the profitability of uneven-sized forestry may be competitive with even-aged forestry. In Finland, management of uneven-sized stands is hampered by the lack of information about the dynamics of such stands, and about the yield and profitability of uneven-sized forestry. This study developed models which allow managers to simulate the growth and yield of uneven-sized stands in Finland, making it possible to predict the yield and analyze the sustainability of different management options. The model set consists of individual-tree diameter increment, height and survival models, and a model for ingrowth. The modeling data consisted of two long-term field experiments of uneven-sized forest management, a set of temporary sample plots measured earlier for growth modeling purposes, and the sample plots of the third National Forest Inventory of Finland. The application area of the models covers all growing sites, all main tree species, and the whole surface area of Finland. According to the models, the sustainable harvest of a fertile (Oxalis-Myrtillus site) uneven-sized Norway spruce forest varies between 5.5 and 7 m³ ha⁻¹ a⁻¹ in Central Finland, depending on the length of the cutting cycle, stand density, and shape of the diameter distribution. It is profitable to harvest large diameter classes more heavily than small ones. Due to the large amount of data the models for diameter increment are highly significant and reliably show the growth level of trees in uneven-sized stands. The weakest models are the ingrowth models, which are based on a clearly smaller data set than the other models.