我国森林生物灾害区划研究

在充分认识森林生物灾害系统的基础上,以承灾体森林植物区系特征为主线,结合孕灾环境的基本特征以及致灾因子的分布情况,在全部国土空间范围内,将我国森林生物灾害划分为3个一级区(灾害大区)9个二级区(灾害区)24个三级区(灾害亚区),并对划分结果进行相似程度对比分析。     

森林火灾风险评估技术体系探讨

综合利用森林火灾致灾危险性、承灾体暴露度、承灾体脆弱性,构建森林火灾风险评估指标体系。致灾危险性选取可燃物、气象条件、野外火源、地形地势等方面的内容为评估指标,承灾体暴露度选取地上活生物量、房屋建筑数量、人口数量、GDP等方面的内容为评估指标,承灾体脆弱性选取易燃林地比例、易燃建筑面积比例、老幼人口数比例、经济活动脆弱性等方面的内容为评估指标。采用层次分析法,通过专家打分的方式,确定各评估指标的权重。将森林火灾风险评估精度细化到小班、30弧秒地理格网,乡镇级、县级等多空间尺度,以满足国家、省、市、县不同行政级别森林防火管理精度需求,同时也为不同地区、不同时期的森林火灾风险识别提出最佳解决方案。     

沿海城市风暴潮灾害脆弱性分析——以山东沿海城市为例

指出了脆弱性评估是防灾减灾规划的基础,将脆弱性表示为暴露性、敏感性、适应能力3个方面的组合,综合考虑山东省风暴潮灾害承灾体的特征,利用效用函数评价法对山东沿海城市的风暴潮脆弱性进行了评价,得出了城市发展水平与脆弱性大小的相关关系。     

我国东北地区栗山天牛灾害成因分析

栗山天牛Massicus raddei引发的栎树林生物灾害在我国东北地区已由次要灾害上升为重要灾害。成灾原因分析表明，致灾因子栗山天牛的K-生态对策是灾害形成的内在原因，承灾体天然次生栎林的脆弱性是灾害形成的外在原因，防灾控灾措施不到位是致使灾害持续加重的人为因素。     

杨树天牛灾害可持续控制策略与技术

人工营建的森林生态系统组分过于单一 ,配置不当是三北地区森林生物灾害严重的根本原因。主要控制策略包括御灾控灾阵地前移 ,控制目标从种群密度控制转为灾害控制 ,对灾害调控从“点状调控”上升为“网状调控” ,提高对“潜在”生物灾害的预警能力。提出生物多样性与生态系统稳定性原理、风险分散理论和抗性相对论作为多树种合理配置抗御人工林生物灾害的 3大理论基础。以多树种合理配置控制杨树天牛灾害为实例 ,从结构和功能的关系 ,将现有防护林划分为 3类 :即一代林网、二代林网和加强型二代林网 ,分析了树种配置结构和抗天牛灾害的功能。进一步将加强型二代林网配置树种类群划分为非寄主树种、目标树种 (或抗性树种 )和诱饵树 ,并对各自的功能进行了定位 ,提出了较为合理的抗御天牛灾害的多树种配置模式以及简便有效的诱饵树管理技术。最后 ,以防护林 (特别是农田防护林 )的经营和管理由静态转变为动态为前提 ,探讨了诱饵树管理的一些新思路     

我国东北地区松材线虫灾害特征分析

依据森林生物灾害系统的基本原理,从致灾因子、承灾体和孕灾环境3个方面对东北地区松材线虫Bursaphelenchus xylophilus灾害特征进行分析。结果显示：东北地区松材线虫入侵途径呈多点多条,正在逐步适应当地的主要松树种类和孕灾环境,可通过云杉花墨天牛Monochamus saltuarius完成自然传播;越年枯死现象较为突出,已形成3个较大的发生集群,表现出典型的外来入侵生物的灾害特征,即灾情严重、损失巨大、发展快速、防控难度大,进一步扩散蔓延的潜在风险极大。     

森林火灾区域风险性分析与防范对策——以河南省范县为例

森林火灾是八大自然灾害之一，具有事发突然、蔓延快、防治难、不确定因素多且损失大的基本特点。以范县地区为例，采集森林火灾可燃调查数据，数据包括地表覆盖物、腐殖质厚度、林木密度、蓄积量、可燃物实验检测等，将调查单元（样方）的危险性评估各项指标数据化和指标化，带入危险性指数计算公式，通过ArcGIS软件导出危险性等级图，并评估单元的承灾体暴露度等级和承受体脆弱性，带入风险指数计算公式进行计算，通过ArcGIS软件导出风险性等级图，分析得出范县总体森林火灾发生可能性和危险性为中等水平，针对此情况采取加强森林防火队伍建设和物资储备措施，做到监管有效、防患未然，为我国平原地区森林防火提供理论依据。     

杨树天牢灾害可持续控制策略与技术

人工营建的森林生态系统组分过于单一，配置不当是二北地区森林生物灾害严重的根本原因。主要控制策略包括御灾控灾阵地前移，控制目标从种群密度控制转为灾害控制，对灾害调控从“点状调控”上升为“网状调控”，提高对“潜在”生物灾害的预警能力。提出生物多样性与生态系统稳定性原理、风险分散理论和抗性相对论作为多种合理配置抗御人工林生物灾害的3大理论基础。以多树种合理配置控制杨树天牛灾害为实例，从结构和功能的关系，将现有防护林划分为3类：即一代林网、二代林网和加强型二代林网，分析了树种配置结构和抗天牛灾害的功能。进一步将加强型二代林网配置树种类群划分为非寄主树种、目标树种（或抗性树种）和诱饵树，并对各自的功能进行了定位，提出了较为合理的抗御天牛灾害的多树种配置模式以及简便有效的诱饵树管理技术。最后，以防护林（特别是农田防护林）的经营和管理由静态转变为动态为前提，探讨了诱饵树管理的一些新思路。     

我国东北地区红脂大小蠹灾害风险分析

参照灾害风险分析方法,通过与华山松大小蠹Dendroctonus armandi、云杉大小蠹D.micans对比分析,从致灾因子的危害性、承灾体的脆弱性和孕灾环境的稳定性3个方面,对东北地区红脂大小蠹D.valens灾害风险进行定性分析。结果表明：红脂大小蠹灾害在东北地区的潜在风险较大,且有向东北腹地进一步扩散危害趋势。     

国家林业新时期的森林生物灾害研究

分析了国家林业新时期的重要特征，认为国家林业新时期是以六大林业重点工程启动为标志，以五大历史性转变为特征的新的发展阶段。阐明了国家林业新时期我国森林生物灾害的特征，包括：以国土生态环境整体恶化为诱导因素的森林生物灾害频繁发生；在西部为主的生态脆弱区，森林的寄主主导性生物灾害发生普遍；已入侵我国的森林有害生物逐步形成稳定生态格局的同时，伴随着国际、国内物流通径的增多和物流通量的增大，境外有害生物入侵的风险不断增强；全球气候变化导致天然林生态系统的生物灾害流行；森林的历史性生物灾害间歇发生的同时，次要性的生物灾害逐步演化成主要威胁；伴随都市化的高速进程，城市森林的生物灾害发生普遍且机理更加复杂。在此基础上提出了国家林业新时期六大工程的森林有害生物防治目标需求和实现对策。进一步提出了森林生物灾害管理的三大技术体系建设及其研究任务。具体内容为：森林生物灾害的信息管理，森林生物灾害的基因管理，森林生物灾害的生态管理。     

Leaf photosynthetic responses and related nitrogen changes associated with crown reclosure after thinning in a young Chamaecyparis obtusa stand

In order to quantify the effects of thinning on biochemical photosynthesis parameters and changes in leaf nitrogen contents associated with the process of crown reclosure, the maximum rate of carboxylation (V _cmax), the leaf nitrogen concentration per unit area (N _a), and the photosynthetic photon flux density (PPFD) were measured at four crown heights in both thinned (1500 trees ha⁻¹) and unthinned control (3000 trees ha⁻¹) stands of ten-year-old Chamaecyparis obtusa (36°3′N, 140°7′E) trees during four consecutive growing seasons after thinning. Thinning increased V _cmax in the lower and middle crowns in the first year after thinning, and leaves in the lower crown of the thinned stand maintained high V _cmax for four years, whereas they abscised in the second year in the control stand. Significant increases in V _cmax were detected even in the upper crowns of trees in the thinned stand in the second year. Thinning did not affect N _a at any of the crown positions in the first year, but significantly increased N _a in the middle crowns from the second year after thinning. Thus, the redistribution of nitrogen between leaves, driven by increases in light and nutrient availability due to the 50% thinning, appears to have enhanced photosynthetic rates in the thinned stand. Thinning also significantly affected the slope of the linear relationship between N _a and V _cmax initially after thinning, but its effect on this relationship was negligible after the second year. These quantitative results may be used to simplify the estimation of the likely effects of management practices on carbon fixation in forest canopies.     

Using canopy heights from digital aerial photogrammetry to enable spatial transfer of forest attribute models: a case study in central Europe

This paper describes a workflow utilizing detailed canopy height information derived from digital airphotos combined with ground inventory information gathered in state-owned forests and regression modelling techniques to quantify forest-growing stocks in private woodlands, for which little information is generally available. Random forest models were trained to predict three different variables at the plot level: quadratic mean diameter of the 100 largest trees (d₁₀₀), basal area weighted mean height of the 100 largest trees (h₁₀₀), and gross volume (V). Two separate models were created – one for a spruce- and one for a beech-dominated test site. We examined the spatial portability of the models by using them to predict the aforementioned variables at actual inventory plots in nearby forests, in which simultaneous ground sampling took place. When data from the full set of available plots were used for training, the predictions for d₁₀₀, h₁₀₀, and V achieved out-of-bag model accuracies (scaled RMSEs) of 15.1%, 10.1%, and 35.3% for the spruce- and 15.9%, 9.7%, and 32.1% for the beech-dominated forest, respectively. The corresponding independent RMSEs for the nearby forests were 15.2%, 10.5%, and 33.6% for the spruce- and 15.5%, 8.9%, and 33.7% for the beech-dominated test site, respectively.     

Plant biological diversity in natural secondary forests on Mao’es Mountains

The forest plant biological diversity investigations were conducted in Laoyeling Forest Ecological Experimental Station on Mao’er Mountains in eastern Heilongjiang Province. Sample plots were six different forest communities. Field works were divided into three seasons: spring, summer and autumn in one year. The results showed that forest plant biological diversity varied with seasons as well as growth forms. Herb species diversity values were the highest in the community growth forms. Diversity indices No,H′ andE ₁ were selected out as the best richness, diversity and evenness indices to indicate the biological diversity in forest community. Responsible editor: Chair Ruibai     

Process-based modelling of the severity and impact of foliar pest attack on eucalypt plantation productivity under current and future climates

We examined the impacts of a defoliating pest, Mycosphaerella leaf disease (MLD), on rotation-length Eucalyptus globulus plantation productivity under current and future climates by using the ecoclimatic species niche model CLIMEX to generate severity, frequency and seasonality scenarios for MLD for specific E. globulus sites. These scenarios were used as inputs to the process-based forest productivity model CABALA. Climate projections from two global climate models were used to drive CABALA with either no or full acclimation of photosynthesis to elevated atmospheric CO₂ assumed. In addition we varied water and nitrogen availability to examine the impacts of different severities of MLD on plantation productivity across environmental gradients. We predicted that, under current climatic conditions, rotation-length reductions in V associated with MLD damage would be no greater than 12%, with an across-site average of 6%. There was considerable between-site variation in predictions that reflected variation in site productivity. Under future climates, we predicted that MLD may reduce rotation length V by as much as 42%, although the reduction averaged across all sites was 11%. The predicted impact of MLD on V was greatest at lower productivity sites. The importance of N and water availability in recovery following MLD attack was highlighted. Uncertainty in model predictions revolved around the climate models used and assumptions of degree of photosynthetic acclimation to elevated CO₂. Large differences in predicted impact of MLD were associated with this uncertainty. Our results suggest that the effects of defoliation due to pests on plantation productivity should not be ignored when considering future management of forest plantations. The approach developed here provides managers with a tool to appraise risk and examine possible impacts of management interventions designed to reduce or manage risk.     

林木直径大小多样性量化测度指数的比较研究

[目的]为了客观恰当地量化表达林分水平上的林木直径大小多样性。[方法]采用6块定位样地数据,对比分析基于直径分布的Simpson(D_N)、Shannon(H_N)及单木断面积Gini系数(GC),基于直径大小分化度的Simpson(DT)、Shannon(HT)及其均值(T-)这6种林木直径大小多样性量化测度指数,筛选出符合逻辑排序且具有较好辨别能力的直径大小多样性量化测度指数。[结果]6块样地的林木直径大小多样性逻辑排序为吉林胡桃楸针阔混交林经营样地吉林胡桃楸针阔混交林对照样地甘肃锐齿栎阔叶混交林经营样地甘肃锐齿栎阔叶混交林对照样地北京油松落叶松人工混交林样地北京侧柏人工纯林;林木直径大小多样性为天然林高于人工林,更为成熟的吉林老龄林样地高于甘肃中龄林样地,经过至少5年结构化经营的样地高于对照样地,人工混交林样地高于人工纯林样地。基于直径分布的DN、HN和GC测度的6块样地林木直径大小多样性排序结果与逻辑排序不一致;基于直径大小分化度的D_T、H_T和珔T测度的各林分林木直径大小多样性排序与逻辑排序一致。[结论]基于直径分布的D_N、H_N和GC量化测度指数不能恰当地表达林木直径大小多样性。基于直径大小分化度的D_T、H_T和珔T量化测度指数能恰当表达林木直径大小多样性;相对D_T和H_T,珔T是一个连续型变量的测度指数,而且能从林分整体水平上量化林木间的大小分化程度,易于解释其生物学意义。因此,认为珔T是恰当表达及区分各林分林木直径大小多样性的最优量化测度指数。     

A silvicultural management tool for the Oriental beech (Fagus orientalis Lipsky) forests

Stand density management tools help forest managers and landowners to more effectively allocate growing space so that specific silvicultural objectives can be met. Due to the economic importance of Oriental beech (Fagus orientalis Lipsky) forests in Turkey, a stand density management tool was developed for this species to optimize regeneration success rate and tree growth. For the development of this tool, named stand density management diagram (SDMD), we utilized forest inventory data from the Kastamonu Regional Forest Directorate in Turkey. Previously published forest management approaches and models were employed during the development of the tool. The SDMD illustrates the relation among four forest indexes: the basal area per hectare, number of trees per hectare, forest stand volume per hectare, and quadratic mean diameter of the beech stands. The stand stocking percent (SSP) can be determined based upon any two of these four measurements. The results suggest that SSP is a better predictor of tree growth than BA in Oriental beech forests. The newly developed SDMD allows for a more effective use of the growing space to achieve specific silvicultural objectives including tree regeneration, timber production, thinning planning, and wildlife protection in Oriental beech forests.     

Moisture-related adjustment factor to obtain a reference ultrasonic velocity in structural lumber of plantation hardwood

Wave propagation techniques based on ultrasound for timber grading are influenced by the moisture content (MC) of wood. The ultrasound velocities at an equilibrium MC (V₁₂) and above saturation point (V_sat) were used to calculate moisture-related adjustment factors (k_H). Tests were conducted using plantation hardwoods (Corymbia citriodora, Eucalyptus grandis and Eucalyptus pellita) grown in Brazil. Below the fiber saturation point (FSP), k_H values were between 0.66% and 0.83%, which concurred with intervals proposed in existing literature for softwoods. However, the k_H inferred from the velocities obtained at MCs above the FSP increased (from 10% to 30%) with increasing density. The sound velocity under saturated conditions (V_sat) obtained by adjustment equations was 2–9% lower than the actual V_sat obtained from the tests. The obtained adjustment factors may be useful for the standardization of nondestructive timber grading based on ultrasound propagation.     

The behaviour of the species mingling index<Emphasis Type="Italic"> M</Emphasis><Subscript><Emphasis Type="Italic">sp</Emphasis></Subscript> in relation to species dominance and dispersion

Ecosystem conservation plays an increasingly important role in forest management. The value for such conservation has been directly linked to high diversity of species and structure within systems. In the past, forestry inventory practices have concentrated on aspects that were primarily required for timber management. Now, however, much interest has arisen in measures that will indicate higher or lower diversity. The interspersion of trees of different species reflects diversity at a local level and may serve as an important indicator for the simplification of a forest or woodland system. This article shows that the mingling index M_sp is robust in describing the spatial dispersion of plants; some guidelines for interpreting M_sp are provided.     

基因分化值和基因调控信息量研究

本文通过对基因调控、表达的分析,探讨了个体分化定量问题,提出用基因分化值D_(?)指标,度量分化细胞之间的内部差异;对调控、表达问题,用信息论的方法加以处理,得到了基因调控熵H_r,再从H_r指标估算出调控信息量。D_(?)具有强度性质;H_r具有容量性质。试验选用同功酶测定这两项分化指标。再用这两项指标进一步讨论分化、进化、生物信息、群体复杂性等问题。     

Microbial biomass in subtropical forest soils： effect of conversion of natural secondary broad-leaved forest to Cunninghamia lanceolata plantation

Conversion of natural secondary broad-leaved forest to Cunninghamia lanceolata plantation is a common management practice in subtropical China. In this study, we compared soil physico-chemical properties, microbial biomass in one natural secondary broad-leaved forest and two C. lanceolata plantation sites to estimate the effects of forest conversion on soil microbial biomass at the Huitong Experimental Station of Forestry Ecology, Chinese Academy of Sciences. Concentrations of soil organic carbon, total nitrogen, NH4^＋-N and microbial biomass carbon and nitrogen were much lower under C. lanceolata plantations as compared to natural secondary broad-leaved forest. Soil microbial biomass C in the first and second rotation of C. lanceolata plantations was only 53%, 46% of that in natural secondary broad-leaved forest, and microbial biomass N was 97% and 79%, respectively. The contribution of microbial biomass C to soil organic C was also lower in the plantation sites. However, the contribution of microbial N to total nitrogen and NH4^＋-N was greater in the C. lanceolata plantation sites. Therefore, conversion of natural secondary broad-leaved forest to C. lanceolata plantation and continuous planting of C. lanceolata led to the decline in soil microbial biomass and the degradation of forest soil in subtropical China.