浙江风水林类型、特点及保护管理探讨

浙江风水林主要包括村落风水林、坟园墓地风水林、寺庙风水林等3种基本类型。阐述了浙江风水林的历史发展过程及浙江先民对风水林的保护管理,总结了浙江风水林的类型及基本特点,并提出风水林的保护管理对策。     

陕西省主要湿地类型及分布特点

湿地资源是相当重要的国土资源与自然资源,其拥有多种功能。根据陕西省第二次湿地资源调查结果,对陕西省主要湿地类型及分布特点进行分析,为进一步保护和开发湿地资源提供借鉴。     

浅谈云南湿地类型分布和特点

据2001年进行的全省湿地资源调查结果,将云南的湿地划分为永久性河流湿地、永久性及季节性淡水湖泊湿地、沼泽草甸湿地等6个湿地类型。详细阐述其数量及分布特点,并进一步分析了云南湿地所具有的多样性、数量多、分布不均匀、水生植被类型多样、野生动物物种数量多等特点,并提出相关问题予以探讨。     

浅谈毕拉河林业局立地类型分布特点

文章分析了毕拉河林业局的立地类型分布与特点。     

森林经营类型的划分及应用

森林分类经营实施后,森林经营类型已成为森林经营过程中合理经营和科学管理的重要依据,文章就林区森林经营类型划分及其在森林经营方案、森林监测中的应用进行了论述。     

近两年洪江市失火案件的特点、原因及预防

森林火灾是突发性很强、危害极大的自然灾害，它破坏生态环境，危及人们生命财产的安全，事关生态建设和环境保护大局，严重影响社会、经济的可持续发展，世界各国对此也普遍予以关注。     

国外松枯梢病症状类型及发生特点

根据作者在“国外松枯梢病综合防治技术研究”过程中的观察和调查,并参阅有关文献,将湿地松和火炬松枯梢病的发病症状归纳为三大类型：干枯型枯梢病、流脂型枯梢病和综合型枯梢病。并对各大类型枯梢病发生特点作简单阐述。     

十堰市绿篱主要类型及应用情况调研

为了解十堰市绿篱的主要种类及应用情况,笔者踏查了十堰市大部分绿篱使用地区,总结了该市绿篱使用种类及主要类型,对应用过程中存在的问题进行了分析,并提出了可行性的发展对策。     

森林火灾扑救类型划分及其特点规律研究

基于我国森林火灾复杂性的特点,本文提出了森林火灾扑救类型划分的原则和方法,系统地阐述了各森林火灾扑救类型的主要特点规律。     

家居内外园林植物生态类型及应用

介绍了现代人对人居环境在园林设计上的要求,从家居内外园林植物生态类型和绿化植物的选择及配置等方面探讨了家居园林植物的应用.     

STUDY ON THE TREE GROWTH, ARCHITECTURE AND STAND STRUCTURE OF KOREAN PINE PLANTATION

lNTRODUCTIONTherhythInofKorcanpinegrowingandtrpearchitectUreissubjectedtoitsownl1crcd-ityandforeststructUre.Tl1cil11portantefTcctsofgapdynamicsarethereasonsthatmaketl1cKoreanpinetrceformhighqualityoftimbcr.Whilecurrentn1anagemcntofKoreanpincforestmainlyfocusesonpurestand,thccco-logicalrelationshipsbetWcenKoreanpineandothcrsPecicsinaconununityareneglected,thcprimitivebiologicalconditionislost.TheKo-reanpinetrecsinplantationcasilydivergeonthctOpofmainsten1,thesescverelyaITectthcgrOedqu…     

Influences of life history, environmental gradients, and disturbance on riparian tree regeneration in Western Oregon

In two related field studies: (1) a multiscale riparian forest inventory and (2) a comparative study of natural forest gap and nongap environments, we explored regeneration patterns of native riparian trees in relation to large- and small-scale ecological drivers in four western Oregon watersheds spanning a climatic gradient from dry to wet. Twenty-three tree species were classified by life history traits into five functional groups that differed in shade and drought tolerance; distribution and abundance of tree regeneration were analyzed by group. For most groups, seedling abundance varied substantially across the large scale climate gradient. In particular, drought tolerant species decreased sharply in abundance from the drier to wetter watersheds. Overall seedling frequency and diversity also decreased from the driest to wettest watersheds, while nurse log use increased. Regeneration of most, but not all, species was greater in gaps.Principal conclusions are that life history information was useful for categorizing species and quite predictive of regeneration behavior overall, yet for many species contextual factors such as climate, forest structure, and adjoining species were also very important. Species appeared to regenerate opportunistically wherever local conditions fell within their environmental tolerances and competitive abilities. Management or restoration of riparian forests, therefore, requires knowledge of site conditions, the life history of the riparian trees present, and in particular an understanding of the species’ environmental tolerances, disturbance responses, and competitive abilities relative to one another.     

湖南牡丹栽培历史和本土牡丹园建设

湖南牡丹药用有2 000多年历史,观赏栽培有1 000多年历史。明清时期形成湘西北以观赏牡丹为主和湘西南以药用牡丹为主的两个栽培中心。永顺县保存下来一批十分珍贵的古牡丹。2007年长沙王陵公园建立了湖南首个本土牡丹园,收集品种20多个,为湖南牡丹种质资源的科学保护及开发利用创造了条件。       

Soil organic carbon and aggregation under poplar based agroforestry system in relation to tree age and soil type

The poplar based agroforestry system improves aggregation of soil through huge amounts of organic matter in the form of leaf biomass. The extent of improvement may be affected by the age of the poplar trees and the soil type. The surface and subsurface soil samples from agroforestry and adjoining non-agroforestry sites with different years of poplar plantation (1, 3 and 6 years) and varying soil textures (loamy sand and sandy clay) were analyzed for soil organic carbon, its sequestration and aggregate size distribution. The average soil organic carbon increased from 0.36 in sole crop to 0.66% in agroforestry soils. The increase was higher in loamy sand than sandy clay. The soil organic carbon increased with increase in tree age. The soils under agroforestry had 2.9–4.8 Mg ha⁻¹ higher soil organic carbon than in sole crop. The poplar trees could sequester higher soil organic carbon in 0–30 cm profile during the first year of their plantation (6.07 Mg ha⁻¹ year⁻¹) than the subsequent years (1.95–2.63 Mg ha⁻¹ year⁻¹). The sandy clay could sequester higher carbon (2.85 Mg ha⁻¹ year⁻¹) than in loamy sand (2.32 Mg ha⁻¹ year⁻¹). The mean weight diameter (MWD) of soil aggregates increased by 3.2, 7.3 and 13.3 times in soils with 1, 3 and 6 years plantation, respectively from that in sole crop. The increase in MWD with agroforestry was higher in loamy sand than sandy clay soil. The water stable aggregates (WSA >0.25 mm) increased by 14.4, 32.6 and 56.9 times in soils with 1, 3 and 6 years plantation, respectively, from that in sole crop. The WSA >0.25 mm were 6.02 times higher in loamy sand and 2.2 times in sandy clay than in sole crop soils.     

美丽胡枝子的生物学特性研究

美丽胡枝子是一速生的豆科灌木树种,具有适应性强,耐旱、耐瘠、花色秀丽等优良特性。通过几年试验研究,分别从美丽胡枝子的自然分布、生境条件、群落结构、生长规律、开花结实、物候特征、萌蘖特性和根系生长特征等方面揭示其生物学特性。     

Detection of individual trees and estimation of tree height using LiDAR data

For estimation of tree parameters at the single-tree level using light detection and ranging (LiDAR), detection and delineation of individual trees is an important starting point. This paper presents an approach for delineating individual trees and estimating tree heights using LiDAR in coniferous (Pinus koraiensis, Larix leptolepis) and deciduous (Quercus spp.) forests in South Korea. To detect tree tops, the extended maxima transformation of morphological image-analysis methods was applied to the digital canopy model (DCM). In order to monitor spurious local maxima in the DCM, which cause false tree tops, different h values in the extended maxima transformation were explored. For delineation of individual trees, watershed segmentation was applied to the distance-transformed image from the detected tree tops. The tree heights were extracted using the maximum value within the segmented crown boundary. Thereafter, individual tree data estimated by LiDAR were compared to the field measurement data under five categories (correct delineation, satisfied delineation, merged tree, split tree, and not found). In our study, P. koraiensis, L. leptolepis, and Quercus spp. had the best detection accuracies of 68.1% at h = 0.18, 86.7% at h = 0.12, and 67.4% at h = 0.02, respectively. The coefficients of determination for tree height estimation were 0.77, 0.80, and 0.74 for P. koraiensis, L. leptolepis, and Quercus spp., respectively.     

对当前昭通市林木种苗管理工作的思考

介绍昭通市林木种苗工作的基本情况,分析全市林木种苗工作发展中存在的主要问题,提出今后一段时期内,昭通市林木种苗管理工作的解决思路。     

Hurricane disturbances,tree diversity,and succession in North Carolina Piedmont forests,USA

Windthrow plays a critical role in maintaining species diversity in temperate forests. Do large-scale strong wind events(i.e., tropical cyclones, including hurricanes,typhoons and severe cyclonic storms) increase tree diversity in severely damaged forest areas? Do hurricanes(tropical cyclones that occurs in the Atlantic Ocean and northeastern Pacific Ocean) lead to altered relative abundance of shade-tolerant and shade-intolerant species? Did historic hurricanes alter the succession trajectory of the damaged forests? We used nearly 70-year tree demographic data to assess the effects of two major hurricanes on woody species diversity in Piedmont forests, North Carolina, USA. Species richness(S) and Shannon–Wiener's diversity index(H') were used to evaluate the changes in tree diversity. The changes in composition were assessed with Nonmetric Multidimensional Scaling. The pre-hurricane successional phase can strongly influence both the damage severity and subsequent responses. Although there is often an immediate drop in diversity following a hurricane, understory tree diversity quickly increases to levels that exceed those prior to the disturbance. This leads to an increase in diversity in stands that were substantially damaged. Hurricanes significantly decrease the dominance of shade-intolerant canopy species while increasing preestablished, more shade-tolerant species. We conclude that large, and infrequent hurricanes help to maintain local tree diversity, but also accelerate the increase in dominance of understory species such as red maple and beech.     

Tree and livestock productivity in relation to tree planting configuration in a silvopastoral system in North Wales, UK

Silvopastoral systems in Europe offer the potential of introducing environmental benefits while at the same time increasing the diversity of farm outputs. The establishment of new silvopastoral systems by planting young trees into existing pasture was investigated at a site in North Wales, UK. Two tree species, sycamore (Acer pseudo-platanus L.) and red alder(Alnus rubra Bong.), were planted into pasture at a range of densities and planting arrangements. Growth of trees planted in farm woodland blocks (2500 stems ha^–1) was compared with the growth of trees planted at 400 stems ha^–1 in clumps and dispersed throughout the plot and at 100 stems ha^–1 (dispersed). Over the first six years after planting, alder trees were significantly taller and larger in diameter than sycamore. Sycamore trees planted at close spacing in farm woodland or clumped arrangements were significantly larger in diameter than widely spaced sycamore at 100 and 400 stems ha^–1. Livestock productivity was unaffected by the presence of trees during the six-year establishment phase of the system. The planting of trees in a clumped pattern appears to combine silvicultural benefits to tree growth with agricultural benefits of maintaining livestock production while trees are established.This revised version was published online in November 2005 with corrections to the Cover Date.     

Fire cycle and fire adaptation of main tree species in Daxing’anling forest region,China

Based on the fire statistics, the Daxing’anling forest area were classified into three fire cycle regions: northern coniferous virgin forest region with a fire cycle ofl 10–120 years, middle conifer-broad-leaved mixed forest region with a fire cycle of 30–40 years, and southern broad-leaved secondary forest region with a fire cycle of 15–20. The percentage of conifers and broad-leaved trees, forest age and natural mature period of main tree species in different fire cycle regions were discussed in concern with fire occurrence. The characteristics of fire adaptation and fire resistance of main tree species, such as sexual and asexual reproduction, were discussed and evaluation of the synthetical fire adaptation was made.