湖南黄桑国家级自然保护区植被景观格局探讨

①斑块特征指数分析表明:各景观类型的密度、分维数指数都较小,植被景观的深展指数都不高,扩散比较均匀,没有极端复杂的形状产生,植被景观在演替系列中还没有普遍达到演替的顶级,斑块之间自相似程度较高。②多样性指数分析表明:总体多样性程度高。景观多样性指数、优势度指数与均匀度指数的结果所包含的意义一致,这种一致性充分说明了各植被景观类型分布均匀,各景观类型地位相差较小。③空间构型指数分析表明:保护区的斑块密度为1.001,即1 km2上有1.001个斑块。这说明斑块数目较少。各景观类型分布也较均匀。保护区景观破碎度指数为0.007,这表明该区植被景观在研究期内所表现的生境破碎化程度是很低的。每一植被景观类型破碎度指数最高的是灌丛和灌草丛景观,其次为栲林景观,其余的破碎度都处于较低的水平。内部生境破碎化指数以灌丛和灌草丛景观、栲林景观为最低,它们的单独斑块面积较大,故破碎化指数较低。其它景观类型的破碎化指数相差不大,这与植被顺向演替是相关的。景观分离度指数的排序结果与斑块密度的排序基本一致。     

A study of habitat fragmentation in Southeastern Brazil using remote sensing and geographic information systems (GIS)

The purpose of this work was to study fragmentation of forest formations (mesophytic forest, riparian woodland and savannah vegetation (cerrado)) in a 15,774-ha study area located in the Municipal District of Botucatu in Southeastern Brazil (São Paulo State). A land use and land cover map was made from a color composition of a Landsat-5 thematic mapper (TM) image. The edge effect caused by habitat fragmentation was assessed by overlaying, on a geographic information system (GIS), the land use and land cover data with the spectral ratio. The degree of habitat fragmentation was analyzed by deriving: 1. mean patch area and perimeter; 2. patch number and density; 3. perimeter-area ratio, fractal dimension (D), and shape diversity index (SI); and 4. distance between patches and dispersion index (R). In addition, the folowing relationships were modeled: 1. distribution of natural vegetation patch sizes; 2. perimeter-area relationship and the number and area of natural vegetation patches; 3. edge effect caused by habitat fragmentation. The values of R indicated that savannah patches (R = 0.86) were aggregated while patches of natural vegetation as a whole (R = 1.02) were randomly dispersed in the landscape. There was a high frequency of small patches in the landscape whereas large patches were rare. In the perimeter-area relationship, there was no sign of scale distinction in the patch shapes. In the patch number-landscape area relationship, D, though apparently scale-dependent, tends to be constant as area increases. This phenomenon was correlated with the tendency to reach a constant density as the working scale was increased. On the edge effect analysis, the edge-center distance was properly estimated by a model in which the edge-center distance was considered a function of the total patch area and the SI.     

Tangential and radial shrinkage variation within trees in sugi (<Emphasis Type="Italic">Cryptomeria japonica</Emphasis>) cultivars

The transverse shrinkage variation within trees was examined for five sugi cultivars. The within-tree trends of tangential shrinkage (α _T) were different by cultivar, whereas radial shrinkage (α _R) increased from pith to bark in most cultivars. The tangential/radial shrinkage ratio (α _T/α _R) decreased from pith to bark in most cultivars, because the radial variation of α _R was larger than that of α _T. The cultivars showed significant differences among cultivars in α _T, α _R, and α _T/α _R, but the difference among cultivars for α _T/α _R was smaller. The relationships between transverse shrinkage and microfi bril angle (MFA), basic density (BD), tree ring parameters, and modulus of elasticity were examined. The α _T and α _R showed positive relationships with BD, latewood percentage, latewood density, and modulus of elasticity, and negative relationships with MFA and ring width. The relationships with earlywood density were weak. Sugi exhibited variation in transverse shrinkage within stem and among cultivars, with the variation affected by MFA, density, and tree ring parameters. Part of this article was presented at the 56th Annual Meeting of the Japan Wood Research Society, Akita, Japan, August 2006, and the 57th Annual Meeting of the Japan Wood Research Society, Hiroshima, Japan, August 2007     

Differences in the forest landscape structure along the Finnish–Russian border in southern Karelia

Abstract

This study describes forest landscape fragmentation and connectivity along the Finnish–Russian border near the Karelian Isthmus. The landscape pattern was analysed using classification data based on Landsat ETM+ and Landsat TM images in combination with systematic surveys in Finland (Finnish National Forest Inventory) (n=546) and the authors’ own fieldwork data in Russia (n=101). On the Finnish side the forest patches are significantly smaller than on the Russian side. In addition, the Finnish forests landscape is more scattered and distances between patches of the same forest type are longer. The Russian side is more dominated by broadleaved and mixed forest stands. The disparities are due to differences in forestry policy and traditions of forest practices. The growing conditions of the areas are similar. The habitat fragmentation and habitat connectivity are important issues because the Karelian Isthmus is one of three main corridors and migrating routes connecting large Russian boreal taiga forests and their fauna and flora with Finnish isolated boreal forests.     

北京城市扩展轴上的绿地景观格局梯度分析

应用梯度分析与景观指数相结合的方法,分析了2004年北京城市绿地系统沿东西和南北两条城市扩展轴分布的空间格局。结果表明:城市绿地整体上破碎化程度高,连通性好,边缘效应较强;从城市中心到边缘,绿化覆盖率不随距城市中心远近而变化,小型斑块数量比例、斑块数量、形状指数、破碎度、平均最近邻体距离等指标则表现出明显的梯度变化;影响绿化覆盖率和斑块面积频率分布的主要因素是公园性质大型斑块的分布状况。研究结果说明:在目前城市绿化覆盖率较难提高的情况下,通过应用梯度分析与景观指数相结合的方法对现有绿地空间结构进行分析调整,不仅能优化城市绿地的景观格局,还能更好地发挥出城市绿地缓解环境问题的功能。     

大型山地城市绿地景观动态及驱动力分析

利用1995年和2007年两期TM和ETM遥感影像数据,结合实地调查,研究了重庆市主城区20世纪90年代中期以来绿地景观格局时空变化特点与成因,讨论了不同绿地类型景观区域格局变化。结果表明,（1）重庆成直辖市以来,研究区整体上绿地景观多样性增加,优势度下降,破碎化增加,景观结构变化呈上升趋势。（2）有林地和其他林地比重减轻,景观破碎度增加;高覆盖度草地面积增加明显,破碎化轻微增加,低覆盖草地破碎化降低。（3）绿地景观斑块形状较规则,其中林地景观斑块形状更复杂,属研究区内优势植被类型。（4）研究区内绿地景观同非绿地景观类型间转化明显,表明其受到较强烈的干扰。其中在海拔200 m以下、坡度6＆#176;下城市绿地受到干扰最强烈。北碚区和沙坪坝区内绿地景观年变化速率最高。（5）自然灾害（火灾和酸雨）和人为经济、社会活动（包括植被经营和管理、旅游开发和其他人为干扰活动等）是研究时段内绿地景观格局变化主要驱动因素。     

南部县升钟水库库区景观格局现状分析与评价

本文结合“3S”技术,利用景观格局分析软件Fragstats3．3,分别从斑块类型水平指数和景观水平指数两个方面对南部县升钟水库库区景观格局现状进行分析与评价。结果表明,研究区林地（针阔混交林、针叶林）和耕地（旱地、水田）控制着整个景观类型,呈现出林地与耕地交错的结构特征。该区域的景观类型丰富,多样性程度高。但是斑块数量多,破碎化程度高,而且景观类型的形状不规则,复杂程度高。林地作为研究区的基质,其面积偏小,并且受到较大程度的人为影响。     

Allomorphs of native crystalline cellulose I evaluated by two equatoriald-spacings

The aim of this study was to develop a facile method for categorizing native celluloses as the algal-bacterial type or the cotton-ramie type and for estimating the I_α/I_β (triclinic/monoclinic) ratio of the cellulose samples. We investigated various native celluloses by X-ray diffractometry; and discriminant analysis was carried out using two equatoriald-spacings: 0.59–0.62 nm (d ₁) and 0.52–0.55 nm (d ₂). All of the samples were classified into the two groups without error. The function used to discriminate between the two groups is represented as:Z=1693d₁ — 902d ₂ — 549, whereZ>0 indicates the algal-bacterial (I_α-rich) type andZ<0 indicates the cotton-ramie (I_β-dominant) type. Another X-ray diffraction study of hydrothermally treatedCladophora cellulose revealed the relation between thed-spacings (d ₁,d ₂) and the I_α/I_β ratio. A calibrating equation by which the I_α/I_β ratio was estimated from the two parameters,d ₁ andd ₂, was then prepared. In the case of relatively highly crystalline native celluloses, it was found that the I_α/I_β ratio is easily determined by applying the two parameters in the equation.     

纳板河自然保护区景观连接度变化分析

自然保护区是保护物种栖息地的重要基础,但频繁的人类活动干扰导致自然保护区内生物栖息地斑块破碎化的问题依然存在,景观连接度定量评价对于保护区生物栖息地保护具有重要作用。以纳板河自然保护区为例,基于图论的指数方法利用2014年和2018年高空间分辨率遥感数据,对保护区栖息地的景观连接度指数的变化及其驱动力因素进行分析。结果表明:1)2014—2018年的景观连接度指数中整体性连接度指数(IIC)、概率连接度指数(PC)都呈现下降趋势,IIC和PC指数分别下降0.29和0.53,指示保护区内栖息地破碎化加剧;2)最大斑块的重要性指数从85.14减少到84.19,重要性前十的斑块时空变化表明了自然保护区栖息地斑块面积不断减小,中部、中西部地区破碎化显著;3)土地利用变化对保护区景观连接度产生重要影响,其中橡胶林、耕地、水库、茶园4类土地利用增加是栖息地破碎化的驱动力因素。研究结果可为纳板河自然保护区栖息地保护管理提供科学依据。     

New diagrams to evaluate soil pore radius distribution and saturated hydraulic conductivity of forest soil

Based on the widely used soil pore classification systems, soil pore ratios α, β and γ were derived. α, β, and γ represent ratios of the fine capillary porosity, coarse capillary porosity, and non-capillary porosity to the effective porosity, respectively. The parametersψ _m and σ of the soil water retention model developed by Kosugi were related to these pore ratios, and a simple method was suggested to estimateψ _m and σ from measured soil pore ratios. By analyzing the observed retention data sets of forest soils, it was shown that the soil pore ratios are effectively used to evaluate the soil pore radius distribution. A coordinate system with log(−ψ _m ) on the abscissa and σ on the ordinate, which represents the constant α, β, and γ lines, was developed as a new diagram to evaluate the soil pore radius distribution in connection with the soil water retention characteristic. Then, the saturated hydraulic conductivityK _s of forest soils was correlated with the parametersψ _m and σ, and with the ratios α, β, and γ using the coordinate system and the triangle diagram. Results showed thatK _s is higher for the soil with a greater median and with a greater width of the pore radius distribution.K _s increases as the non-capillary pore ratio γ becomes greater and the coarse capillary pore ratio β becomes smaller. Functional relationships betweenK _s and the water retention parameters, and betweenK _s and the soil pore ratios were derived based on Mualem's model. The title is tentative translation from the original Japanese title by the author of this paper.     

信宜市土地利用景观格局研究

以广东省信宜市为研究区,利用patch analyst景观格局分析软件,选取斑块数目、斑块面积、斑块密度、平均斑块大小、斑块面积标准差、斑块面积变异系数、平均斑块形状指数、面积加权平均斑块形状指数、平均斑块分维数、面积加权平均斑块分维数、破碎度、均匀度和多样性指数等指标,对信宜市土地利用景观格局进行分析.结果表明:各类...     

Pyrolysis reactions of various lignin model dimers

Primary pyrolysis reactions and relative reactivities for depolymerization and condensation/carbonization were evaluated for various lignin model dimers with α-O-4, β-O-4, β-1, and biphenyl substructures by characterizing the tetrahydrofuran (THF)-soluble and THF-insoluble fractions obtained after pyrolysis at 400°C. Reactivity was quite different depending on the model structure: depolymerization: α-O-4 [phenolic (ph), nonphenolic (nonph)], β-O-4 (ph) > β-O-4 (nonph), β-1 (ph, nonph) > biphenyl (ph, nonph); condensation/carbonization: β-1 (ph) > β-O-4 (ph) > α-O-4 (ph) > β-O-4 (nonph), biphenyl (ph, nonph), α-O-4 (nonph), β-1 (nonph). Major degradation pathways were also identified for β-O-4 and β-1 model dimers: β-O-4 types: C_β-O cleavage to form cinnamyl alcohols and phenols and C_γ-elimination yielding vinyl ethers; β-1 types: C_α-C_β cleavage yielding benzaldehydes and styrenes and C_γ-elimination yielding stilbenes. Relative reactivities of these pathways were also quite different between phenolic and nonphenolic forms even in the same types; C_β-O cleavage (β-O-4) and C_γ-elimination (β-1) were substantially enhanced in phenolic forms.     

怒江流域中段典型地区(福贡县)景观格局变化研究

基于GIS 技术,以怒江流域中段典型地区(福贡县)为研究区域,利用1986 年、1994 年和2004年TM卫星遥感影像,分析了3个时期的景观格局特征及其变化.结果表明,怒江流域中段典型地区(福贡县)整体景观以有林地为基质,灌木林以及其它景观类型镶嵌于其中.有林地的面积1986～2004年呈持续减少趋势;灌木林、荒草地、耕地、滩涂和城镇则是持续增加.斑块数持续增加,景观破碎化趋势明显;景观多样性指数增加、优势度指数减小,景观趋于多样化和均匀化;斑块被分割严重,景观总体连通性下降.人为干扰是导致该区景观格局发生变化的主要驱动因子.     

Contemporary pollen flow and mating patterns of a subtropical canopy tree Eurycorymbus cavaleriei in a fragmented agricultural landscape

China's subtropical forests have experienced severe deforestation and most native forests have been fragmented into an archipelago-like landscape. The genetic effect of habitat fragmentation depends largely on the level of gene flow within and among population fragments. In the present study, Eurycorymbus cavaleriei, a canopy tree found throughout subtropical China, was selected as a representative insect-pollinated plant species to assess genetic consequence of forest fragmentation. Contemporary pollen dispersal and mating patterns were estimated in two physically isolated stands of E. cavaleriei within fragmented forests using six highly polymorphic microsatellite loci. We found high genetic diversity (H_E = 0.670–0.754) in both adults and offspring in the fragmented agricultural landscape, suggesting that habitat fragmentation did not necessarily erode genetic diversity of E. cavaleriei. Although substantial pollen travelled less than 100 m, paternity analysis revealed that a large amount of long-distance pollination events occurred, with the average pollen dispersal distance being 1107 m and 325 m for the two stands, respectively. Extensive pollen immigration (39.3–42.6%) indicated that there was effective genetic connectivity among E. cavaleriei stands in the fragmented forests. twogener analysis revealed that the exponential power model was the best-fitting dispersal curve with a fat-tailed (b < 1) dispersal feature. The results from a multilocus mating system analysis suggested that a small amount of biparental inbreeding and some correlated mating events occurred in the fragmented forests, which were similar to our parallel findings in the continuous forests of E. cavaleriei. Estimates of pollen pool structure (Φ_FT = 0.128–0.174) indicated large genetic differences between pollen clouds accepted by maternal trees. The number of effective pollen donors (N_ep) in E. cavaleriei, estimated using both mltr (N_ep = 4.2–5.3) and twogener (N_ep = 2.9–3.9) models, was equivalent to the number of effective pollen donors detected in continuous forests of E. cavaleriei. The pollen dispersal and mating patterns detected here indicated that habitat fragmentation did not have a negative impact on pollen movement in E. cavaleriei, possibly due to its generalist pollination system and the resilient foraging behavior of its pollinators in response to changes in landscape structure. The long distances of pollen-mediated gene flow between patches highlight the conservation value of remnant forest fragments in maintaining genetic connectivity at the landscape scale in subtropical China.     

八英庄林场砬沿沟流域森林景观变化分析

为更好地实现八英庄林场森林资源的优化配置,以河北省木兰围场国有林场管理局八英庄林场2010年和2015年2期地形图、遥感图像及二类调查数据为基础,运用ArcGIS10.0和Fragstats4.2软件,对砬沿沟流域森林景观变化进行分析。砬沿沟流域按一级景观分类划分,斑块类型共5类,有林地斑块面积由473.95hm~2增加为500.88hm~2,其他斑块面积相对减小;有林地的景观形状指数、散布与并列指数减小,分别由3.008 1、59.106 6降为2.481 6、49.060 4;景观多样性由0.426 9减小为0.233 4,说明各斑块的聚集程度有所增加,各斑块之间的连通性有所提高。砬沿沟流域按二级景观分类划分,在有林地类型中,2010年和2015年斑块类型都为5类,到2015年山杏林斑块消失,新增云杉林斑块;2010至2015年华北落叶松林斑块面积、斑块景观形状指数均增加,山杨林斑块面积、斑块景观形状指数均减小。砬沿沟流域森林景观香农多样性指数由1.602 7降为1.389 2。除去一级景观分类中有林地斑块破碎度减小,其他无论是一级景观分类还是二级景观分类,各斑块破碎度都有不同程度的增加,说明近5a一级、二级斑块在总数上有所增加,并且增加的斑块相对独立,并不连续。     

Individual and synergistic toxicity of solanaceous glycoalkaloids against two coleopteran stored-product insects

Toxicity of solanaceous glycoalkaloids against stored-grain insects was investigated under laboratory conditions. The total glycoalkaloids (TGAs), α-chaconine and α-solanine from potatoes, Solanum tuberosum L. and α-tomatine from tomatoes, Lycopersicon esculentum Mill. were isolated and tested in this bioassay. Their acute and residual toxicity were assessed against the rust red flour beetle, Tribolium castaneum Herbst (Coleoptera: Tenebrionidae), and the rice weevil, Sitophilus oryzae L. (Coleoptera: Curculionidae). All compounds were tested either individually or as binary mixtures. Results revealed considerable toxicity of the tested glycoalkaloids against the target insects. When adults of S. oryzae were exposed to a dry-film residue of these phytochemicals, the total glycoalkaloids (TGAs) fraction was the most toxic, followed by α-solanine, α-chaconine, and α-tomatine with LC_50s of (38.6 and 22.1), (48.2 and 38.9), (52.00 and 41.6), and (82.3 and 67.00) μg/cm² at 24 and 48 h post-treatment, respectively. The order of toxicity against T. castaneum in a descending order was TGAs > α-chaconine > α-solanine > α-tomatine. All compounds were more toxic when insects were fed grains treated with these phytochemicals (LC_50s of TGAs were 7.4 and 16.2 mg/kg grains at 48 h post-treatment against S. oryzae and T. castaneum, respectively. All compounds, particularly the TGAs, exhibited promising residual toxicity effects. Toxicity of glycoalkaloids was exceeded when tested as binary mixtures indicating their synergistic interaction. The study recommends the use of glycoalkaloids of Solanaceae as biorationals and natural leads to protect stored grains from insect infestation.     

Landscape pattern and fragmentation of natural secondary forests in the eastern mountainous region, northeast China: A case study of Mao'ershan forests in Heilongjiang Province

Mao'ershan region is a representative natural secondary forested region in the eastern mountainous region, northeast of China. Under the support of ARC/INFO and GIS technology, the landscape shape and fragment indices of Mao'ershan experimental plantation were studied by combining the forest type map (1∶10000), which was drawn from the aerial photographs (1999), field investigation (1999) and soil utilized map (1∶10000). The results showed that the shape index and shape fragment index of natural landscape were higher than those of artificial landscapes and landscape patch fragment index depended on the number of patches. The natural forest had complex shape, suffering little jamming, and its shape index was higher than that of artificial forest. The manual controlled landscape (e.g. nursery, cropland and cutting blank) had regular shape, and its shape index was smaller. The fragment index of patches in natural forest was higher than that of artificial forest. The soft broad-leaved had the highest fragment index of patch amount. Foundation item: This paper was supported by National Key Technologies P&D Program of China during the 10^th Five-Year Plan Period (2002BA515B040). Biography: LI Shu-juan (1977-), female, Lecturer in Ocean University of China, Qingdao 266003, P. R. China. Responsible editor: Zhu Hong     

Effects of side-chain hydroxyl groups on pyrolytic <Emphasis Type="Italic">β</Emphasis>-ether cleavage of phenolic lignin model dimer

Effects of side chain hydroxyl groups on pyrolytic β-ether cleavage of phenolic model dimers were studied with various deoxygenated dimers under pyrolysis conditions of N₂/400°C/1 min. Although phenolic dimer with hydroxyl groups at the C _α ⁻ and C _γ ⁻positions was much more reactive than the corresponding nonphenolic type, deoxygenation at the C _γ -position substantially reduced the reactivity up to the level of the nonphenolic type. These results are discussed with the cleavage mechanism via quinone methide intermediate formation, which is activated through intramolecular hydrogen bonds between C _α ⁻ and C _γ ⁻ hydroxyl groups.     

Feasibility of a harvesting system for logging residues as unutilized forest biomass

The concept of a “harvesting system for unutilized forest biomass by a processor and a forwarder” is examined for the purpose of constructing a system to harvest logging residues (or slashes) as a new resource for energy. The rate of slash harvesting, α, and the energy input rate of hauling slashes,p (%), are defined as indices of the possibility of harvesting slashes and the utilization of slashes for energy, respectively. From an analysis of the field experiment, both the volume of logs hauled by the forwarder per day,E _F (m³/day), andp are expressed as functions of the hauling distance,L(m). The productivity of the processor,E _P (m³/day), andL were used to calculate α. Results showed that α was approximately 0.95 for the experiment site, indicating that almost all the slashes could be hauled. It was recognized that the energy utilization of slashes was feasible for this site becausep was less than 1 %. The hauling cost per unit weight of slashes was calculated as 15.4 yen/kg on an oven-dry weight basis. This high cost clarified that the cost must be reduced by taking measures such as enhancing the hauling efficiency of the forwarder. A part of this paper was orally presented at the 5th Annual Meeting of the Japan Forest Engineering Society (1998).     

基于MODIS卫星影像的湖南省景观格局

景观格局是由自然或人为形成的一系列大小、形状各异,排列不同的景观要素共同作用的结果.利用2005年MODIS卫星数据,经过一系列处理后得到湖南省景观图.利用决策树分类法将研究区分为5种景观类型:水、自然植被、耕地、城镇用地、其它用地.选取斑块数、斑块密度、破碎度、斑块分维数、多样性指数、优势度、均匀度、聚集度、分离度等景观指数,从斑块、斑块类型和景观3个层次上对研究区景观格局进行定量分析.结果表明:湖南省景观斑块共39357块,总面积为21.1984万km2;在5种景观类型中,植被和耕地是主要景观类型,占研究区总面积的88.38%;湖南省景观多样性程度低,且斑块空间形状简单.