不同人为干扰强度对米槠林乔木层组成和物种多样性的影响

本文从乔木层组成和物种多样性角度探讨不同人为干扰强度(天然米槠林CK、A级择伐更新、B级皆伐迹地天然更新、C级皆伐迹地人工促进天然更新和D级杉木林)对福建武平米储林恢复的影响.结果表明CK、A级和B级乔木层都是以米储为优势种,C级顶极种米槠处于第2优势种,阳性树种裂斗锥处于第1优势种,而D级受人工种植的影响乔木层优势种发生根本性变化而以杉木为优势种;通过乔木层组成和物种多样性分析,随着人为干扰强度的加大种类组成、各科含种数、各科含属数和各属含种数上升到B级或C级后下降或直接下降,而物种多样性指数和均匀度呈线性下降、优势度呈线性上升.特别是D级杉木林乔木层由于以人工种植杉木为优势种控制着整个群落的性质和环境、导致分析的各方面指标与天然米槠林CK相距甚远,目前较难恢复到米槠顶极群落,其余更新方式将能恢复到米槠顶极群落.     

海南岛热带山地雨林皆伐后不同更新方式对土壤物理性质的影响及恢复研究

通过样地调查和取样测定,运用方差分析、差异显著检验和聚类分析方法,以海南热带山地雨林原始林(0501,植被类型代码)为对照,对热带山地雨林皆伐后的天然更新林(0502)、皆伐炼山后人工促进天然更新林(0503)和皆伐炼山后种植人工林(0504)等3种次生林的土壤物理差异和恢复程度进行了研究,结果表明:(1)热带山地雨林采伐更新造成土壤密度的增加和表层毛管孔隙度的差异,进而引起总孔隙度的变化,影响040 cm土层的最小持水量及2040 cm土层的毛管持水量;皆伐天然更新措施(0502样地)的土壤质地较好,表层土粒淋洗下移较少,整个剖面土壤毛管孔隙度较高,土体发育良好,具有很强的持水保水能力;皆伐炼山措施(0503和0504样地)使表层土壤易于向下淋溶和淀积,底层毛管孔隙度降低,增加了中层土壤密度并形成明显的淀积层,影响土壤的通气透水性能,容易造成雨季地表径流和旱季底层水分难向上传输;人工造林更新措施(0504样地)造成土壤表层土粒淋洗严重,各层毛管孔隙度降低和中、底土层非毛管孔隙度的减少,中、底土层明显的板结,影响林地的通气透水性能,各种持水保水能力大大降低,容易产生地表径流和存在土壤表层砂化危险.(2)皆伐天然更新林具有与原始林相似的土壤物理性质.人工促进天然更新林土壤属黏壤土至黏土质地,表层毛管孔隙度较大,底层毛管孔隙度最小及持水量递减率明显.人工更新林土壤为砂质黏壤土至黏土,表层土粒淋溶下移和砂化现象明显,中、底土层具有明显淀积层,持水保水能力最低.(3)皆伐迹地天然更新林(0502)和人工促进天然更新林(0503)土壤物理恢复程度较接近原始林,人工更新林(0504)土壤恢复程度明显不及天然更新林,次生林的土壤总孔隙度和持水量恢复较好,土壤颗粒比例较难恢复,表层土壤密度和中层土壤粉黏比的恢复度较差,中层土壤的毛管与非毛管孔隙度之比的恢复度较表层和底层高,皆伐炼山对深层土壤的恢复影响较大.     

不同时空尺度下武夷山甜槠林物种多样性与生物量的动态关系

研究武夷山中亚热带甜槠常绿阔叶林9600和400m2样地物种多样性和生物量的动态关系。结果表明:随着演替进展,9600m2样地生物量增加,物种丰富度在群落总体、乔木层和下木层均表现为下降趋势,个体数量在群落总体表现为下降趋势,在乔木层表现为先增加后下降的趋势,在下木层表现为先下降后增加的趋势,Shannon-Wiener指数在群落总体和乔木层均表现为下降趋势,在下木层表现为先下降后增加的趋势,均匀度指数在群落总体、乔木层和下木层均表现为先下降后增加的趋势;400m2样地物种多样性各指标在不同层次不同时间进程中表现出明显的异质性,2001—2004年,随着活立木生物量的增加,下木层Shannon-Wiener指数和物种丰富度明显下降,2004—2007年,乔木层Shannon-Wiener指数和物种丰富度明显下降,物种多样性各指标与活立木生物量间均不存在显著相关性(P0.05)。物种多样性对生态系统功能的影响在不同的时空尺度中差异明显。     

干扰对天然红松林植物多样性的影响

对长白山林区受不同程度干扰（择伐）的红松林与红松林被皆伐后形成白桦次生林的植物多样性进行了研究，结果表明，白桦群落及其下木层的多样性高于各类型的红松林。不同类型的红松林中，以轻度干扰的红松原始群落及其立木层和草本层的多样性最大，这是群落长期演容、物种适应的结果。白哗群落处于演替的第二阶段，群落中侵入了较多的耐荫树种，加之林内光照条件好，故而有发达的下木层，致使树种的多样性很高。本文还分析了多样性与均匀度及生境条件的关系。     

海南霸王岭陆均松类热带山地雨林伐后林结构与物种多样性研究

霸王岭林区是海南岛最典型的热带山地雨林分布区.在该区,现存分布面积最广、资源数量最大的是热带山地雨林的各种伐后林.以霸王岭分布最广的以陆均松(Dacridium pierrii)为主的山地雨林的伐后林为对象,研究了其组成、径级、高度结构和物种多样性特征,对比分析了伐后林与原始林以及伐后林不同类型之间的异同.结果表明:原始热带山地雨林经采伐后中小乔木和灌木的优势度增大,而大乔木树种的优势度则明显下降.阳性树种的种类、数量和相对重要性随采伐破坏的程度而增加.伐后林中矮、小树木在林分中比例随采伐破坏的程度增加,而高、大树木,特别是进入主林层树木的比例则随采伐破坏的程度明显下降.从林分测树因子的变化来看,采育择伐和径级择伐的林分要优于大强度择伐和皆伐的林分.原始林的物种丰富度大于伐后林,但其多样性指数和均匀度指数大都小于伐后林.组成上与原始林相似性较大的伐后林是各种择伐后的林分,而皆伐后的林分与原始林在组成上已有很大差别.     

江西九连山不同恢复模式林分的物种多样性特征

[目的 ]分析人工恢复和自然恢复两种恢复模式下林分结构、物种组成与原始林的差异,了解不同恢复模式下森林生物多样性的变化规律,为森林生态系统人工恢复和重建提供理论和实践依据。[方法 ]选择九连山境内由人工种植杉木自然恢复36年形成的针阔混交林、皆伐后自然恢复32年的亚热带次生常绿阔叶林和未受人为干扰的原始森林(以下分别简称为杉木林、次生林、原始林)为研究对象,分析3种林分不同生长发育阶段(幼树1 cm≤DBH5 cm、小树5 cm≤DBH10 cm和成年树DBH≥10 cm)的物种组成、物种多样性及优势度、群落结构和功能群变化等,探究不同恢复模式下亚热带森林物种多样性恢复的特征变化。[结果 ]杉木林共有木本植物4 983株,隶属于29科75种;次生林共有2 879株,隶属于26科73种;原始林共有4 770株,隶属于38科126种。原始林与杉木林幼树的胸高断面积为次生林的2倍;小树阶段3种林分无显著差异;次生林和杉木林成年树的胸高断面积分别为原始林的37%和70%。杉木林与次生林在种-面积、种-多度及种-物种等级上的变化趋势大致相同;幼树阶段,次生林物种数随着抽取个体数增加积累速度高于杉木林;成年树阶段,杉木林物种个数的积累速度要快于次生林。杉木林和次生林总体的物种丰富度比较接近,约为原始林的55%,但次生林幼树及成年树的物种丰富度少于杉木林。总体上次生林的Shannon-Wiener指数显著地高于杉木林,各生长阶段并无显著差异。次生林在幼树、小树阶段的DBH和树高均显著大于杉木林,成年树阶段的DBH则显著小于杉木林。次生林各生长阶段的先锋种重要值均为最大,杉木林成年树的耐荫种重要值最小。[结论 ]人工恢复与自然恢复群落的物种组成、物种多样性、物种个数都能朝着当地顶级群落演替。相对于自然恢复的次生林,人工恢复的杉木林在短期恢复中有利于物种个体数及生物量的积累,能更快的形成复杂垂直结构的森林群落;但自然恢复的次生林更有利于物种多样性的恢复。     

徐州石质山地人工林物种多样性及群落稳定性

以徐州石质山地上发育的人工侧柏林和刺槐林为研究对象,在群落学调查的基础上,分析了人工林的物种多样性和群落稳定性,探讨了人工植被的动态特征和变化规律.结果表明:现有人工林的物种组成和结构发育存在较大差异,结构复杂的群落物种多样性高,刺槐林的群落总体多样性大于侧柏林;人工林优势种群的自我更新较弱,现有人工林均处于不稳定状态;现阶段人工林的变化主要反映在灌木和草本层;复杂的群落结构、丰富的物种多样性有利于群落的稳定,故可通过抚育间伐、补植和引入乡土树种等促进人工林的稳定发展.     

南岭山地杉木人工林与天然林群落特征研究

通过设置临时样地,对南岭山地九连山自然保护区人工杉木林(28a)和天然杉木林(100a)进行群落学特征比较研究.结果表明:两种起源的杉木林物种组成差异不大,人工林有维管植物39科59属83种,天然林有52科72属93种,二者种组成相似程度较高,相似性系数迭0.592,尤其是下木层和草本层;同时,二者物种多样性及均匀度也相似,但除下木层外,人工林乔木层和草本层的多样性指数和均匀度指数比天然林要低,而生态优势度正与此相反.人工林乔木层生态优势度最高;天然林与人工林杉木种群都属衰退型种群,一些中生或阴生及常绿阈叶树种却属增长型种群,这表明天然林与人工林杉木林都正在向常绿阔叶林演替.     

皆伐前后油松人工林下植物多样性变化及与土壤水分的关系

【目的】探讨油松人工林皆伐前后林下植物多样性的变化及与土壤水分的关系,为在油松林皆伐后植被恢复和发育阶段维持生物多样性、保持林分结构稳定、发挥更高生态效益等方面提供科学依据和经营措施建议。【方法】采用时序研究法,在河北平泉地区选择立地一致的不同林龄油松人工林(32年中龄林、40年近熟林、53年成熟林)和皆伐后不同时间(5、10、24 a)的天然更新林作为研究对象,分析不同生长发育阶段油松人工林下植物物种组成与多样性的变化规律及与土壤水分间的相关性。【结果】1)皆伐前后6种林分样地共出现灌木植物21种,草本植物65种,不同样地林下植物组成存在差异。胡枝子在各林分样地均有出现,且重要值均> 20%,在灌木层优势地位明显;草本层中菊科植物种类最多,有18种,其次是蔷薇科和禾本科,分别为6种和4种。2)不同林分样地林下植物多样性指数均表现为草本层>灌木层,皆伐前随着林龄增加林下植物多样性逐渐增加;皆伐后灌木层植物多样性表现为先下降后增加再下降,且变化幅度明显,伐后10 a灌木层Margalef丰富度指数、Simpson多样性指数、Shannon-Wiener多样性指数和Pielou均匀度指数最大,分别为1.40、0.61、1.24和0.74,与53年样地差异不显著。皆伐后不同时间的天然更新林草本层植物多样性均与伐前53年样地的差异不显著,皆伐对灌木层植物的影响较大。3)不同林地土壤水分变化规律较一致,表现为伐前随林龄增加而逐渐增加,伐后5~10 a仍保持较高水平,伐后24 a出现下降,经相关分析植物多样性指数与土壤水分之间有显著的正相关关系,与草本层的相关性达极显著水平。【结论】伐前林下植物多样性变化主要与林分密度降低、光照条件改善有关,伐后主要与油松天然更新及种间竞争有关。依靠油松天然更新恢复的林地保持了较高的生物多样性,但在皆伐10 a后出现下降的趋势,建议在此时对油松更新苗进行人工抚育、降低密度以维持植物多样性。土壤水分是影响植物多样性的关键生态因子,良好的土壤水分条件和林下植被的恢复和发展可以相互促进。     

马尾松母树人工促进更新的效果分析

对马尾松阔叶树混交林皆伐后留马尾松母树及保护阔叶幼树人工促进天然更新效果进行调查研究。结果表明 ,与皆伐炼山栽松群落相比 ,所形成的林分林木生长良好 ,并能以较少的投入获取较高的经济效益 ;同时群落物种丰富度和多样性指数较高且分布较为均匀 ,林地土壤与林分能保持良好的肥力水平与较高的水源涵养功能 ,是科学经营松阔混交林、保护物种多样性与维持森林良好生态功能的有效营林措施。     

Effects of topography and management history on natural forest recovery in abandoned forest after clear-cutting in Miyazaki, Japan

We investigated factors limiting the recovery of natural forest in former large-scale conifer plantations abandoned after clear-cutting in southwestern Japan. We analyzed forest recovery status (“recovered” sites covered by evergreen broad-leaved trees, and “unrecovered” sites covered by pioneer community or nonvegetated sites) using aerial photographs and field survey. We applied logistic regression analyses to evaluate the effects of topography, construction of harvesting roads, distance from remnant forest, stand condition before clear-cutting, and prior land-use history on forest recovery. Human factors, i.e., land use and clear-cutting age, were found to affect to forest recovery more than environmental factors such as topography. Harvesting roads had the strongest negative impact on forest recovery. Forest recovery after clear-cutting of young sugi plantations also took longer than after clear-cutting of old sugi plantations or evergreen broad-leaved forests. Furthermore, areas formerly utilized as meadows recovered less successfully than those that had been managed as coppices. The influences of these factors were thought to be promoted by the advance reproduction as the regeneration sources for forest recovery. The influence of stand age before logging suggested an effect of thinning, which might alter the abundance of advanced reproduction in the understory. However, distance from remnant forest appeared to be less important. An influence of topography was also detected, but this could be partly explained by the existence of advance reproduction in the understory in certain topographic positions. Thus, our analysis suggests that regeneration sources originating from advanced reproduction in plantations play a significant role for the recovery of natural forest after clear-cutting.     

红松皆伐迹地更新红松的效果分析

为了探讨红松皆伐迹地更新红松的效果,对红松皆伐迹地更新的红松的生长情况进行了调查研究,结果表明：红松皆伐迹地更新红松效果不良,无论是胸径还是树高,其生长量都比较缓慢,荒山荒地更新的红松,胸径生长量比红松皆伐迹地高32%,树高生长量高62%;红松皆伐迹地的土壤理化性质均不如荒地,针叶N、P、K的含量和叶面积指数皆低于荒地,更新10年后根系的分布,无论是水平分布还是垂直分布,都远不如荒地的更新效果。建议对红松皆伐迹地应该培养人工阔叶林或人工针阔混交林。     

Silviculture as a disturbance regime: the effects of clear-cutting,planting and thinning on polypore communities in mixed forests

The structure of modern forest landscapes is profoundly affected by human-caused disturbances, particularly forest management; however, the effects and prospects of individual silvicultural techniques are insufficiently understood. This study distinguishes the effects of clear-cutting, planting and thinning on species richness and community composition of polypore fungi. In 2008–2009, 181 forest compartments (ranging from naturally regenerated deciduous stands to planted Picea abies stands and 0–137 years post clear-cutting) were explored in a hemiboreal landscape subjected to even-aged management. Altogether 104 polypore species were recorded. For species richness, time since clear-cutting was the most influential factor at both stand and landscape scales, followed by thinning. Clear-cuts had distinct polypore communities (including several red-listed species) whose species richness declined in time. Following 20 years post clear-cutting, species richness started to increase along different community–composition pathways determined by regeneration type. The communities developed after planting were moderately species rich at stand scale but homogeneous over larger areas. Thus, at landscape scale, mature unmanaged naturally regenerated stands hosted most species; thinning reduced species richness by approximately 15%, and among thinned stands, planted areas had a further 9–22% fewer species than naturally regenerated areas. In such variably managed landscape, silviculture appeared to create particularly distinct communities in young stands on nutrient-rich soils, which naturally provide polypores with a rich supply of small deciduous snags absent from stands artificially planted with P. abies and intensively thinned.     

小陇山锐齿栎天然林空间结构特征

研究小陇山3个类型锐齿栎天然林的直径分布和空间结构参数(混交度、角尺度和大小比数),分析其空间结构特征.结果表明:王安沟100多年未经人为干扰的锐齿栎天然林和响潭沟皆伐迹地上经近40年封山后自然恢复的次生林均表现为异龄林的直径分布特征,但从q值来看,王安沟锐齿栎天然林直径分布较响潭沟次生林更加合理,白营西沟择伐林的直径分布虽然表现为小径木占的比重比较大,但各径阶间的变幅平缓,有明显人为干扰的痕迹;王安沟锐齿栎天然林和白营西沟次生林林木个体分布角尺度均值分别为0.489和0.487,林分内林木整体分布格局属随机分布,响潭沟次生林林分角尺度均值为0.520,其林木水平分布格局表现出轻微的团状分布,群落还处于演替的早期阶段;3个林分中王安沟锐齿栎天然林的树种隔离程度最高,响潭沟次之,白营西沟最低,混交度分别为0.598,0.542和0.451;白桦、华山松在不同的林分中所处的地位不同,从王安沟锐齿栎天然林、响潭沟次生林到白营西沟择伐林表现出大小比数依次降低的趋势,而锐齿栎、漆树等树种则在3个林分中所处的地位一致;人为干扰对白营西沟次生林的结构特征有明显的影响.     

Restoration and Rebuilding of Forestry Ecological System in Heilongjiang Province

IntroductionHeilongiiangProvinceisoneoftheIargestforestryregionsinChina,whichisnamedaspreciousregionsofforestsdeposits.Greatamountoftimberandrnanykindsofforestproductshavebeenproducedthere.Thedenseforestshaveprovidednaturaldefenseforthesucceedinghighand's…     

皆伐对细叶龙竹林分生长的影响研究

研究了不同皆伐方式、不同皆伐季节、不同伐桩高度、不同施肥方法以及不同松土深度对细叶龙竹林生长的影响。结果显示:小面积皆伐有利于机械化采伐作业,可降低劳动成本,提高劳动生产率,在生产上宜选择带状皆伐方式,带宽以8~12 m为佳;皆伐季节宜在冬季进行;伐桩高度以保留5~10 cm为宜;皆伐后进行伐桩施肥效果好于土壤施肥,以施复合肥为好;竹林伐后进行垦覆有利于竹林生长,松土深度应在20 cm以上。     

The role of different sources of tree regeneration in the initial stages of natural forest recovery after logging of conifer plantation in a warm-temperate region

We analyzed the role of regeneration type (surviving from advanced regeneration, resprouting from advanced regeneration, or newly recruited seedlings) in determining the quantity and quality of individuals in reestablishing a natural forest following clear-cutting of a conifer plantation. We experimentally clear-cut a plantation and undertook a detailed tree census before and after clear-cutting. After clear-cutting, a species composition partially representing warm-temperate evergreen broadleaf forest was present in the form of surviving and resprouted individuals originating from advanced regeneration that had established in the Chamaecyparis obtusa plantation. On the other hand, seedlings that established after clear-cutting were dominated by pioneer species, and the number of seedlings was far greater than the number of individuals originating from advanced regeneration. Our results suggest that the role of regeneration type would differ in relation to the objectives for forest recovery. When any kind of woody cover of the ground surface after clear-cutting would suffice, we suggest that the contribution of pioneer seedlings originating from buried seeds would be important. If the recovery objective is to form a simple evergreen broadleaf forest, such as a coppice woodland, all three sources of regeneration would play a similar role, provided the understory before clear-cutting was as well developed as the one in this study. If rapid establishment of a lucidophyllous forest with diverse species composition is desired, the role of the surviving and resprouting individuals originating from the advanced regeneration would be much more important.     

The effects of forest type on soil microbial activity in Changbai Mountain,Northeast China

Key message

Forty years after clear-cutting mixed old-growth forest (broadleaf/Korean pine) in the Changbai Mountain area (Northeast China), a mixed forest with natural broadleaf regeneration and larch plantation displayed larger microbial biomass and activity in the soil than either a naturally regenerated birch forest or a monospecific spruce plantation.

Context

Clear-cutting with limited restoration effort was until the end of the twentieth century the norm for managing primary forests in Northeast China. Forest restoration plays an important role in the recovery of soil quality after clear-cutting, but the effects of different regeneration procedures on forest soil quality remain poorly known in Northeast China.

Aims

We assessed the effects of three regeneration procedures, i.e., (i) naturally regenerated birch forest, (ii) spruce plantation, and (iii) naturally regenerated broadleaf species interspersed with planted larch on soil quality and microbial activity in the Changbai Mountain area. An old-growth mixed broadleaf/Korean pine forest was used as a reference.

Methods

Physical and chemical properties and microbial biomass were recorded in the soil. Basal respiration and carbon mineralization were measured with a closed-jar alkali-absorption method.

Results

Microbial biomass was smaller in the birch forest and spruce plantation than in the old-growth and the mixed broadleaf/larch forests. Moreover, microbial biomass, microbial quotient, and potentially mineralizable carbon were larger in the mixed broadleaf/larch than in the birch forest, while no difference was found between spruce plantation and birch forest for microbial biomass and microbial quotient. Basal respiration and metabolic quotient were larger in the birch forest as compared to the three other forest types, indicating a larger energy need for maintenance of the microbial community and lower microbial activity in the naturally regenerated birch forest.

Conclusion

Mixed broadleaf/larch forest displayed a larger microbial biomass and higher substrate use efficiency of the soil microbial community than either naturally regenerated birch forest or spruce plantation. The combined natural and artificial regeneration procedure (mixed broadleaf-larch forest) seems better suited to restore soil quality after clear-cutting in the Changbai Mountain.

     

Wood Use and Forest Management for Carbon Sequestration in Community Forestry in Sierra Juárez,Mexico

Forest managers and policy-makers are being encouraged to incorporate carbon sequestration as a criterion for decision-making. This is a great challenge for small-scale forestry where the conspicuous lack of practical knowledge available for managers prevents the implementation of criteria to promote carbon sequestration. The carbon simulation model CO2FIX combined with local data could provide valuable information for C sequestration in these small-scale forestry systems. The research reported here focuses on community forestry located in the Juarez Mountain Range (Oaxaca State, Mexico), and analyzes the influences of forest management and wood-use (20 scenarios based on five forest management plans and four wood-use strategies) on the changes of C stock (biomass C, soil organic C, products C and fuelwood C) over time. The comparison of the whole stocks to reference results show that group-selection, based on an uneven-aged forest management system involving small patches, has only about half the C benefit relative to clear-cutting harvesting. A forest management strategy focused on oak logwood has a lower C benefit (70 %), and a forest management strategy focused on oak fuelwood has a higher C benefit (120 %) relative to the average of the studied wood-use strategies. Thus, in the study area forest managers and policy-makers who wish to mitigate climate change should increase the rotation period from 40 to 50 years in clear-cutting areas, continue with 40 years in group-selection areas, and promote the use of oak for bioenergy.     

浅谈阔叶次生林的人工促进天然更新

人工促进天然更新是恢复和发展天然阔叶林的重要更新方式,具有投入少、恢复快、收益大和易于实施等特点.人工促进天然更新的阔叶次生林与人工营造杉木林样地比较结果表明,在同一立地条件下,同龄阔叶树的树种种类、郁闭度、生物多样性、高径比等各项生长指标均高于人工杉木林.文中阐述了人工促进天然更新中的抚育间伐、林分改造、封山育林和封禁保护、补植等具体措施,并提出保护现有阔叶林,实施人工促进阔叶林天然更新,扩大水源涵养林、水土保持林等防护林比重等建议.