小兴安岭阔叶红松林粗木质残体基础特征

以小兴安岭典型阔叶红松林大面积固定样地(9hm2)为对象,分析粗木质残体(CWD)的物种组成及数量特征、径级结构、存在形式、腐烂等级,揭示小兴安岭阔叶红松林CWD的基础特征。结果表明:9hm2典型阔叶红松林固定样地内共计有胸径≥2cm的CWD3418株(由于高度腐烂鉴别不出种的CWD有864株,占总个体数的25.3%),CWD的密度、胸高断面积和体积分别为380株.hm-2、15.80m2.hm-2和90.1m3.hm-2;花楷槭和枫桦是阔叶CWD的主要组成树种,红松和冷杉是针叶CWD的主要组成树种;针叶树种的胸高断面积(9.12m2.hm-2)和体积(57.68m3.hm-2)分别达到总体CWD的57.7%和64%;在各存在形式下不同种的CWD数量随着径级的增加而减少,均呈反J型;除未知种以外,其他CWD都主要以枯立木、干基折断和干中折断形式存在;针叶树种根桩形式CWD的数量随着径级的增加而增加,这一规律有别于其他种;样地内各树种CWD腐烂等级都大致呈正态分布,主要集中在Ⅱ和Ⅲ腐烂等级上;除针叶树种的Ⅴ腐烂等级外,各树种不同腐烂等级CWD的数量都随着径级的增加呈减少的趋势。     

2种火烧强度对大兴安岭偃松落叶松林粗木质残体的影响

比较了大兴安岭地区的偃松落叶松原始林和2种不同火烧程度森林类型(轻度火烧林、重度火烧林)之间粗木质残体(Coarse Woody Debris,CWD)组成的差异。结果表明:原始林、轻度火烧林、重度火烧林的CWD蓄积分别为59.92m3/hm2,199.77m3/hm2,217.73m3/hm2,原始林和火烧林之间CWD材积之间有差异,而2种火烧林之间没有差异,说明火灾干扰改变了偃松落叶松林的CWD的组成结构,但是不同的火烧程度对森林CWD的影响程度差不多。原始林和重度火烧林CWD径级大部分为2～20cm,其中立枯木、倒木和伐桩分别占各自总蓄积量的34%,64%,2%和94%,5%,1%,轻度火烧林CWD大部分径级2～10cm,其中立枯木、倒木和伐桩分别占总蓄积量的47%,50%,3%,由此可看出3种不同林型的CWD都集中在小径级的立枯木和倒木中,即小径级的立枯木和倒木是3种林分CWD的主要来源。火烧后偃松落叶松林的蓄积量增加明显,因此可认为火烧可以增加森林CWD的输入量。     

湖南莽山针阔混交林粗死木质残体的研究

通过实地调查,对湖南莽山国家森林公园针阔混交林的粗死木质残体(CWD)现状进行研究,以揭示莽山典型森林CWD的发生特征及分布规律,为莽山森林资源的经营与保护提供理论依据.通过在莽山针阔混交林内设置一个面积0.15 hm2样地,并将其分成15个小样方,调查分析每个小样方内CWD的输入方式、径级结构、贮存量和腐烂等级.莽山...     

缙云山常绿阔叶林粗木质残体储量及特征

【目的】实地调查缙云山常绿阔叶林粗木质残体(CWD)的储量和特征,分析其影响因素,为深入认识常绿阔叶林生态系统中与粗木质残体相关的物质循环等关键生态过程提供理论依据,并为全球碳汇及相关学科的研究提供基础数据。【方法】以缙云山常绿阔叶林内已建立的2块0.5 hm^2样地为对象,调查并分析样地CWD的储量、类型组成、分解等级、径级分布格局以及地形对CWD储量的影响。【结果】缙云山常绿阔叶林CWD储量为38.42 t·hm^-2,其中倒木、枯立木、大枯枝和木桩储量分别为27.70,4.91,2.91和2.90 t·hm^-2,倒木是CWD的主要组成部分; CWD的树种组成与群落优势树种的组成相似,栲占CWD总量的88.44%;从径级分布来看,直径>35 cm的倒木和枯立木是CWD的主体; CWD主要处于分解中后期,中级分解和高级分解CWD的比例分别为63.20%和23.01%;地形对CWD的分布具有显著影响,坡面和山脊CWD储量高于沟谷(P<0.01)。【结论】缙云山常绿阔叶林CWD储量较大,处于该类森林系统的前列; CWD主要以处于分解中后期的优势种大径级倒木和枯立木为主,并主要分布在坡面和沟谷。在森林管理中应降低对CWD的人为干扰和去除,维持森林中枯立木、倒木、大枯枝和树桩等组分的自然状态。     

大兴安岭林区粗木质残体管理评析

通过对林区粗木质残体界定、研究方法、生态功能的介绍,探讨粗木质残体在森林生态系统中的作用。指出大兴安岭地区粗木质残体研究不够深入,并针对目前国内外粗木质残体研究现状总结出应加强对大兴安岭林区粗木质残体的研究与管理,并加强森林经营与林业生态研究的结合,使我国对粗木质残体研究更具普遍性,从而得出更具科学性的结论为森林经营管理提供参考。     

森林粗木质残体研究综述

森林粗死木残体（coarse woody debris,CWD）是指所有地上和地下小头直径≥2．5cm的枯立木（snag）、倒木（Log）、树桩（Stump）、大枯枝（Large Branch）、小枯枝（Twig）、连接在活树上的枯死小树枝（Suspended Twig）等的总称。该文综述了近几十年CWD的研究成果,总结了CWD的概念及其在碳氮循环、生物多样性维护等方面的生态功能,CWD的贮量和养分动态。大量的研究证明,CWD对森林生态系统具有重要的生态功能,但它的蓄积量、空间分布以及它的生态意义因所研究的森林生态系统植被林型而异。另外,CWD还受诸多生物学和非生物学因子的影响,研究各因子与CWD的关系对于保持CWD的生态功能也是十分必要的。     

森林生态系统粗木质残体生态功能研究

粗木质残体(CWD)是森林生态系统中重要的结构性与功能性单元。本文在对国内外CWD 研究历史进行简要回顾的基础上,对其生态功能及其分解过程进行了系统分析。指出了目前CWD 研究的热点及存在的问题,并建议加强对CWD生态服务功能的定量化研究,为其在维持生物多样性、生产力和其它生态过程方面的经营管理提供科学指导。参57。     

森林生态系统粗死木质残体的研究进展

详细论述了粗死木质残体(CWD)的内涵及其分类系统,对国内外粗死木质残体的研究动态进行了梳理与归纳,并指出CWD的生态功能已引起国内外研究者的广泛重视,特别是对CWD的贮量、分解量(率)、养分贮量(C、N等)、动态变化过程及其特征、CWD对森林生态系统的更新演替和生物多样性的保护功能、强大的水土保持功能(抑制水土流失、改善土壤质地)以及与水土保持相关的幼苗保育功能等方面都作了较多的论述和研究.     

大明山常绿阔叶林粗死木质残体贮量的初步研究

以2008年初遭受特大冰雪灾害干扰的大明山国家级自然保护区常绿阔叶林为研究对象,分别坡位设计调查样区,样区内采用相邻网格样方法设置调查样地27个,样地总面积为10 800 m2。采用样方收获法测定林地上的粗死木质残体(Coarse Woody Debris,CWD)贮量及其腐解等级特征。结果表明:大明山常绿阔叶林的粗死木质残体贮量为33.142 t/hm2,其中倒木占CWD总贮量的95.75%。各腐解等级的贮量百分比序列为2级(60.8%)3级(21.7%)4级(13.6%)5级(3.9%)。2008年初的冰雪灾害干扰造成大明山常绿阔叶林的非正常CWD贮量骤然增大,高达20.172 t/hm2。     

抚育间伐对鲁中山区油松人工林生长的影响

以淄博市鲁山林场的油松人工林为研究对象,从胸径、单株材积和单位面积蓄积量3个林木生长指标来分析抚育间伐对林分生长的影响。结果表明,与对照样地相比,2000年抚育间伐的油松人工林在2001—2004,2005—2008和2009—2012年的平均胸径生长量分别提高了7.28%,78.95%和205.00%,平均单株材积生长量分别提高了15.38%,101.75%和312.24%。此外,与对照样地相比,2000年抚育间伐的油松人工林在2005—2008和2009—2012年的单位面积蓄积量分别提高了84.18%和294.50%。可见,抚育间伐可有效促进油松的生长,该研究为人工林抚育间伐提供了科学依据。     

Decreasing the error in the measurement of the ecosystem effective leaf area index of a Pinus massoniana forest

Decreasing the forest ecosystem leaf-area index error(LAIe)helps accurately estimate the growth and light energy utilization of aboveground foliage.Analyzing light transmission in forest ecosystems can effectively determine LAIe.The LAI-2200 plant canopy analyzer(PCA)is used extensively for rapid field-effective LAI(LAIe)measurements and primarily to measure forest canopy LAIe values.However,sometimes this parameter must also be measured in forests with small clearings.In this study,we used the LAI-2200 PCA to obtain one A-value and four B-values each for the canopy,herbaceous layer,and forest ecosystem LAIe.Field measurements showed that the three LAIe types were obviously different.In certain quadrats,the average herbaceous layer(Dicranopteris dichotoma Bernh.)LAIe apparently exceeded that of the Pinus massoniana forest ecosystem.The sources of this error were measuring and recording A-value readings for small canopies and underestimating the ecosystem LAIe.We obtained similar coefficients of determination for both the pre-recomputation and post-recomputation of the canopy and forest ecosystem LAIe(R^2C 0.96 and R^2C 0.99,respectively);thus,the error was decreased.Measuring field LAIe with the LAI-2200 PCA and recomputation should compensate for LAIe underestimation in complex forest ecosystems.     

Coarse woody debris and wood-colonizing fungi differences between a reserve stand and a managed forest in the Taborz region of Poland

The aim of this research was to evaluate the amount of woody debris (m3/ha) on the forest floor and the associated wood-colonizing fungi. The study was performed in the Taborz region, known for its Scots pine provenance experiments, against the background of a recently launched Polish legislation to protect the biodiversity on the forest floor in managed (harvested) stands. We investigated a managed stand (136-years-old) and the reserve stand ‘Sosna Taborska’(261-years-old). In the reserve stand, the mean volume of woody debris was six times higher than in the managed forests, i.e. 65 versus 11 m3/ha. In addition, in the reserve stand, the number of fungi taxa colonizing the dead wood was larger than in the managed stands, with a higher number of fruitbodies. Total fungal richness was higher in the reserve than in the managed stand, i.e. 28 versus 12 species. The dominant taxa at both sites were Fomitopsis pinicola and Fomes The aim of this research was to evaluate the amount of woody debris (m^3/ha) on the forest floor and the associated wood-colonizing fungi. The study was performed in the Taborz region, known for its Scots pine provenance experiments, against the background of a recently launched Polish legislation to protect the biodiversity on the forest floor in managed (harvested) stands. We investigated a managed stand (136-years-old) and the reserve stand ‘Sosna Taborska’(261-years-old). In the reserve stand, the mean volume of woody debris was six times higher than in the managed forests, i.e. 65 versus 11 m^3/ha. In addition, in the reserve stand, the number of fungi taxa colonizing the dead wood was larger than in the managed stands, with a higher number of fruitbodies. Total fungal richness was higher in the reserve than in the managed stand, i.e. 28 versus 12 species. The dominant taxa at both sites were Fomitopsis pinicola and Fomes fomentarius, although some taxa were only found in the reserve (e.g., Stereum hirsutum). The volume of woody debris as well as the diversity of fungi in the managed stand were lower than in the reserve, albeit greater than in other Scots pine stands in Poland. These results testify to the gains in biodiversity yielded by the management conservation management approach at the reserve stand.     

湖南楠木次生林胸径地位指数表的研制

以湖南省1989—2014年6期一类调查数据为基础,筛选出楠木株数占比大于20%的55块样地共299组年龄-胸径值,编制了楠木次生林地位指数表,为湖南省楠木次生林立地质量评价提供参考依据。用10个常用的数学模型对胸径生长进行拟合,理查德模型的相关系数最大(R^2=0.956),残差平方和最小(SSE=3.950),将其作为导向曲线方程,表达式为D=15.6829(1-e^-0.0457A)^1.0597。以40a为基准年龄,3cm为地位指数级距,得到9、12、15、18和21cm共5条地位指数曲线,分别采用标准差调整法、变动系数调整法和相对优势胸径法进行胸径地位指数表的编制,其中标准差调整法所展开的地位指数表落点检验精度高达(98.96%),不跳级比率为76.67%,且无跳2级或以上的现象,因此以该方法来展开湖南楠木次生林胸径地位指数表。以胸径评价林分立地质量,编制胸径地位指数表,其精度高,适用性强,能较好地反应林木的生长特性。     

马尾松大径材优良家系幼林期生长表现

2011年于大型水库周围的湖南省青羊湖国有林场营造马尾松大径材家系试验林,造林半年和1年3个月后分别观测其幼林期的生长表现。结果表明:马尾松大径材家系幼林期的地径、树高以及冠幅生长量的差异均达到了极显著水平,不同家系地径、树高、冠幅的变异系数均在19%以上。不同年份间不同家系地径的变异系数大于树高的,地径的变异系数在年度间变化不明显,而树高的变异系数则2012年的明显小于2011年的。27个大径材优良家系造林1年3个月后,以80、425、38、34的生长表现最好,其树高、胸径和冠幅均生长良好;27个家系的树高生长量均超过了国家标准1年生树高的生长量,全部家系的平均树高远远超过国家标准1年生树高的生长量;34号家系的树高超过了国家标准2年生树高的生长量。马尾松大径材家系幼林期各生长性状,包括2011年地径、2012年地径、2011年树高、2012年树高、2012年冠幅等,除2011年地径与树高相关性不显著外,其余各因子间的相关性均达显著或极显著水平。     

Long-term dynamics of large woody debris in a managed boreal forest stream

Little is known about how past forest management in Sweden influenced the quantity and quality of large woody debris (LWD) in streams. The present study provides information of the long-term dynamics of LWD in a reach of a boreal stream intersecting a managed forest. Dendrochronological methods were used to reconstruct mortality years of the pieces of LWD and the general history of fire and cuttings of the surrounding riparian forest. Today, spruce dominates among the living trees, whereas the LWD is dominated by birch in the forest and by pine in the stream. Fire frequency prior to active fire suppression was similar to values reported from boreal forests. Pine trees were more abundant in the riparian forest before selective logging operations and active fire suppression began in the 1800s. Many of the pieces of LWD found in the stream today died more than 200 years ago and derived from a cohort of pines that generated in the early 1600s. Pine LWD in stream channels is highly resistant to decomposition and can reside for more than 300 years. A substantial amount of the LWD found today in managed forest streams in boreal Sweden most likely derives from the time before extensive human influence and is likely to decrease further in the future. Management of riparian forests to ascertain future supply of long-lived LWD in streams should target to increase the proportion of pine trees.     

厦门城市森林马尾松宽带更新改造技术研究

厦门城市森林中马尾松劣质林分比例大,采用不同改造方式试验表明:宽带采伐更新改造效果较好,阔叶树种造林成活率高,幼林生长比较快,适宜阳性、强阳性和中性偏阳树种。且宽带更新改造技术较简单,可操作性强,便于推广应用。     

Effects of management on coarse woody debris volume and composition in boreal forests in northern Sweden

Forest management practices have led to a reduction in the volume and a change in the composition of coarse woody debris (CWD) in many forest types. This study compared CWD volume and composition in reserves and two types of managed forest in the central boreal zone of Sweden. Ten areas were surveyed, each containing clear-cut, mature managed and old-growth stands, to determine the volume of standing and lying CWD in terms of species composition, decay class and size class. Volumes of CWD on clear-cuts and in mature managed forests were high compared with previous studies. Old-growth forests (72.6 m³ ha^?1) contained a greater volume of CWD than mature managed forests (23.3 m³ ha^?1) and clear-cuts (13.6 m³ ha^?1). Differences were greatest for the larger size classes and intermediate decay stages. Despite stand ages being up to 144 years, CWD volume and composition in managed forests was more similar to clear-cuts than to old-growth forests.