天宝岩自然保护区长苞铁杉混交林粗木质残体蓄水能力研究

选择天宝岩国家级自然保护区内4种不同长苞铁杉混交林(A~D)粗木质残体(CWD)为研究对象,采用自然风干法与室内浸泡法对不同类型(倒木、枯立木、树桩)和不同腐烂程度(Ⅰ~Ⅴ级,腐烂由轻到重)CWD的蓄水能力进行测定分析和对比研究。结果显示:(1)CWD有效拦蓄量在不同长苞铁杉混交林下表现为:长苞铁杉+石栎+马尾松混交林(B,14.21t/hm2)长苞铁杉+甜槠+青冈混交林(C,7.78t/hm2)长苞铁杉+青冈+深山含笑混交林(D,6.99t/hm2)长苞铁杉+猴头杜鹃混交林(A,4.74t/hm2),而在各CWD类型下表现为:倒木(19.579t/hm2)枯立木(8.494t/hm2)树桩(5.661t/hm2)。(2)各长苞铁杉混交林CWD的蓄水量和蓄水速率在蓄水过程中都表现为BDCA,而在脱水过程中都表现为BCAD。(3)不同腐烂等级的CWD按其蓄水量、蓄水速率和脱水速率大小排列皆为:Ⅱ级Ⅵ级Ⅲ级Ⅴ级Ⅰ级。研究表明:CWD蓄水量的大小差异与群落类型、腐烂等级、CWD本身持水性等因素有关,其蓄水和脱水的速率与其持水量、蓄积量以及腐烂等级之间也存在密切的联系;CWD的自然持水率随腐烂等级增加呈增加趋势,而且腐烂等级越高CWD蓄水速率变化也越明显,CWD腐烂等级对其蓄水能力影响较大;倒木具有较好的持水能力,并在蓄积量上远大于树桩和枯立木,对降雨有较强的实际拦截能力。     

川西亚高山森林木质残体及其附生苔藓持水特性

木质残体及其附生苔藓是森林生态系统的基本结构,在水源涵养、水土保持、生物多样性保育、碳和养分循环等方面具有重要作用。然而,有关亚高山森林木质残体及其附生苔藓的水源涵养功能研究尚未见报道。因此,以川西亚高山针叶林区紫果云杉原始林、岷江冷杉原始林、方枝柏原始林等8种典型森林类型为研究对象,调查研究了木质残体及其附生苔藓持水能力随林型、腐烂等级和径级的变化特征。结果表明：（1）亚高山针叶林木质残体饱和储水量在林型之间变化显著。其中,紫果云杉原始林具有最大的饱和储水量（22.06 mm）,柳树次生林木质残体饱和储水量最小（4.55 mm）,但林型之间木质残体饱和持水率的差异不显著。（2）不同林型的附生苔藓持水能力具有显著差异。其中,紫果云杉原始林木质残体附生苔藓饱和储水量最高（7.01 mm）,方枝柏原始林最低（0.21 mm）。（3）腐烂等级显著影响木质残体饱和储水量,IV腐烂等级的饱和储水量较高（3.77 mm）,II腐烂等级较低（0.75 mm）;木质残体饱和持水率和附生苔藓饱和储水量与腐解程度显著正相关,均符合Q（Q''）=ex²+fx+g的函数关系式。（4）木质残体和附生苔藓的饱和储水量均随径级增大而升高,大径级（D5）的饱和储水量占比分别超过60%和40%。可见,林型和木质残体腐解程度及径级大小是决定亚高山针叶林区木质残体及其附生苔藓持水性能的关键因子,特别是附生苔藓对于提高亚高山针叶林水源涵养具有重要作用。     

广州三种森林粗死木质残体（CWD）的储量与分解特征

粗死木质残体(Coarse Woody Debris, CWD)对森林生态系统的稳定性具有不可忽视的贡献.对广州3种森林CWD的储量与分解特征进行了调查分析,结果表明:(1)CWD储量及其与相应森林总生物量比值均表现为常绿阔叶林>针阔混交林>针叶林;枯立木与倒木为CWD的主要成分,其中,针叶CWD主要物种为马尾松(Pinus massonianai),阔叶CWD物种主要为荷木(Schima superba)与黄杞(Engelhardtia chrysolepis)等.(2)CWD径级主要集中在<10cm的范围内,存在状态主要为中级腐烂状态,干扰与竞争是3种森林CWD产生的主要因素.(3)针叶林、针阔混交林与常绿阔叶林CWD的分解常数k分别为0 0244、0.0407和0.0487,即分解速率为常绿阔叶林>混交林>针叶林;随着CWD的分解,N、P与木质素的含量逐渐升高,C、C/N与木质素/N呈降低趋势.     

气候变化情景下天宝岩国家级自然保护区森林景观演替长期动态模拟

气候变化将会对森林树种结构、空间结构以及林龄结构等产生重大影响,准确预测森林景观演替对未来气候变化的响应,不仅能够为科学管理森林生态系统提供理论依据,而且对制定生物多样性保护与珍稀物种保护策略也具有重要意义。本文运用LANDIS Pro 7.0与LINKAGES模型,模拟天宝岩国家级自然保护区8个树种在2种不同气候变化情景(RCP4.5和RCP8.5)下未来300年的森林植被演替动态,分析森林景观格局变化特征及其对气候变化的响应。结果表明：毛竹、马尾松、猴头杜鹃、长苞铁杉以及杉木的潜在面积分布与景观格局指数对气候变化的响应较为显著。在气候变化情景下,各树种的景观分维度均介于1.03—1.08,保护区内各景观斑块相对简单规则。毛竹、猴头杜鹃和杉木聚集度下降趋势明显而斑块密度显著上升,长苞铁杉随演替进行面积逐渐减少而聚集度相对较高且斑块密度剧增,马尾松斑块密度缓慢增加而聚集度先降后升,随气候变化这些树种的景观完整度都遭到了不同程度的破坏,且在RCP8.5气候情景下景观破碎化更严重。而气候变化对阔叶林与柳杉的影响则较小,且阔叶林在演替期间斑块密度下降而聚集度稳中有增,潜在面积分布呈现出良好的...     

亚高山林区河岸带康定柳木质残体持水能力随径级的变化特征

为了解亚高山林区河岸带木质残体的持水能力,以王朗国家级自然保护区亚高山林区河岸带康定柳(Salix paraplesia)直径>30、30～20、20～10、10～5、5～2和2～1 cm六个径级的木质残体为研究对象,运用浸泡模拟法研究了其吸水过程和持水能力随径级的变化特征。结果表明:不同径级木质残体的最大持水量为1024.78～2674.67 g·kg^-1,不同径级木质残体的持水量大小顺序为10～5、20～10、30～20、>30、2～1、5～2 cm;不同径级的木质残体在吸水过程中随着浸泡时间的增加,其饱和含水量不断升高,吸水速率不断降低。同时,30～5 cm径级的木质残体具有良好的持水能力与吸水能力。川西亚高山林区不同径级的康定柳木质残体持水能力差异明显,建议在河岸带保留较大径级的木质残体,有利于提高河岸带水源涵养功能。     

物华天宝——记福建天宝岩国家级自然保护区的野果资源

天宝岩自然保护区,位于福建省永安市东南方向约36公里处的戴云山山系之中,山高林密,沟谷深邃,优越的自然条件孕育了种类繁多的野生动植物,是闽中地区一颗璀璨的植物资源明珠。     

湖南乌云界自然保护区典型生态系统的土壤持水性能

土壤持水性能是决定生态系统水源涵养能力的关键,是自然保护区生态服务功能的重要方面。以湖南省乌云界自然保护区为研究区域,选取森林、灌丛、竹林和草地4个典型生态系统,采用野外调查采样和室内分析的方法研究了土壤的物理性质和持水性能。结果表明,乌云界4种典型植被下表层0—20cm土壤有机质含量普遍较高(>76 g/kg)、容重较低(<0.85 g/cm3)、团聚体稳定性较强(>5mm水稳性团聚体达22.7%—52.3%),表明保护区土壤的结构发育总体上较好。森林和竹林土壤具有较多的大孔隙和较高的饱和导水率,有利于天然降水向地下水的转化,而灌丛和草地土壤毛管孔隙度则相对较高,其土壤中能够保持更多的有效水分。乌云界自然保护区4个典型生态系统0—40cm土层土壤重力水容量为:森林(83.5 mm)>竹林(79.2mm)>灌丛(66.9 mm)>草地(43.8 mm),有效水容量为:草地(128.7 mm)>灌丛(111.6 mm)>森林(95.9 mm)>竹林(83.9mm)。在明晰土壤总蓄水容量(>0 MPa)、重力水容量(0—0.01 MPa)、有效水容量(0.01—1.5 MPa)、无效水容量(>1.5 MPa)等概念的基础上,建议用重力水容量和土壤有效水容量两个指标来评价生态系统土壤的水源涵养功能,其中土壤重力水容量可以反映生态系统补充地下水和调控河川径流量的能力,而土壤有效水容量可以反映生态系统本身保蓄水分的潜力,这些指标均可以通过土壤水分特征曲线进行求算。乌云界自然保护区森林和竹林土壤对于补充地下水和调控河川径流量的能力较强,而灌丛和草地土壤保蓄水分的能力较强。     

Concept and Classification of Coarse Woody Debris in Forest Ecosystems

Coarse woody debris (CWD) is generally considered as dead woody materials in various stages of decomposition, including sound and rotting logs, snags, and large branches. CWD is an important functional and structural component of forested ecosystems and plays an important role in nutrient cycling, long-term carbon storage, tree regeneration, and maintenance of heterogeneous environmental and biological diversity. However, the definition and classification of CWD have been the subject of a long debate in forest ecology. CWD has not been precisely defined. Recently, with the rapid development of landscape ecology in CWD, the USDA Forest Service and the Long Term Ecological Research (LTER) have provided a standardized definition and classification for CWD, which makes data comparison in landscape scale possible. Important characteristics of their definition include: (1) a minimum diameter (or an equivalent cross-section) of CWD ≥10 cm at the widest point (the woody debris with a diameter from 1 to 10 cm should be defined as fine woody debris, and the rest is litterfall); and (2) sound and rotting logs, snags, stumps, and large branches (located above the soil), and coarse root debris (larger than 1 cm in diameter). This classification has greatly facilitated CWD studies. Therefore, it has been widely applied in some countries (particularly in North America). However, this classification has long been a source of confusion for forest ecologists in China. Furthermore, different definitions and criteria are still adopted in individual studies, which makes the interpretation and generalization of their work difficult. This article reviewed recent progress in classifying CWD, with an emphasis on introducing the classification system of the USDA Forest Service and the LTER. It is expected that this review will help facilitate the development of standardized definition and classification suitable to forest ecosystems in China. Translated from Acta Ecologica Sinica, 2005, 25(1) (in Chinese)     

Concept and Classification of Coarse Woody Debris in Forest Ecosystems

Coarse woody debris (CWD) is generally considered as dead woody materials in various stages of decomposition,including sound and rotting logs,snags,and large branches.CWD is an important functional and structural component of forested ecosystems and plays an important role in nutrient cycling,long-term carbon storage,tree regeneration,and maintenance of heterogeneous environmental and biological diversity.However,the definition and classification of CWD have been the subject of a long debate in forest ecology.CWD has not been precisely defined.Recently,with the rapid development of landscape ecology in CWD,the USDA Forest Service and the Long Term Ecological Research (LTER)have provided a standardized definition and classification for CWD,which makes data comparison in landscape scale possible.Important characteristics of their definition include:(1) a minimum diameter (or an equivalent crosssection) of CWD≥10 cm at the widest point (the woody debris with a diameter from 1 to 10 cm should be defined as fine woody debris,and the rest is litterfall);and (2) sound and rotting logs,snags,stumps,and large branches (located above the soil),and coarse root debris (larger than 1 cm in diameter).This classification has greatly facilitated CWD studies.Therefore,it has been widely applied in some countries (particularly in North America).However,this classification has long been a source of confusion for forest ecologists in China.Furthermore,different definitions and criteria are still adopted in individual studies,which makes the interpretation and generalization of their work difficult.This article reviewed recent progress in classifying CWD,with an emphasis on introducing the classification system of the USDA Forest Service and the LTER.It is expected that this review will help facilitate the development of standardized definition and classification suitable to forest ecosystems in China.     

古冰缘地貌森林粗木质残体水分和养分保持功能研究

基于辽东山地老秃顶子古冰缘地貌森林中主要树种的粗木质残体(CWD)样本,利用自然风干、室内浸泡、X荧光光谱方法,对CWD样本的吸水速率、持水率和养分元素含量进行系统分析研究。结果显示:(1)在水分保持功能方面,CWD样本在累计8h的浸泡过程中,6个主要树种CWD可吸持相当2.533mm降雨的水量,其中前15min(0.25h)吸水量占总吸水质量的60%;各性状CWD比较显示,以海拔900m以上、阔叶树种、高中腐级、根桩和倒木的CWD持水性较强。(2)在养分元素保持功能方面,CWD边材C含量为78.96%,心材为96.05%;边材中N、Ca、Si、K、Mg、P等6种养分元素的含量分别为心材的4.93、5.88、10.79、2.72、1.25、2.38倍;不同性状CWD边材中,诸元素含量略有差别,其中C元素在针叶树、高腐级、枯立木边材中含量最高,而N元素在阔叶树、低腐级、枯立木边材中含量最高。研究表明,辽东山地古冰缘地貌森林生态系统中,CWD有重要的吸持水分功能以及营养元素的缓释和富集功能,CWD中更接近外界的边材部分较心材有更强的元素缓释和富集的功能;CWD是古冰缘地貌土壤覆盖率低、土层薄而贫瘠的森林中重要的生态组分。     

Effects of Forest Type and Disturbance on Diversity of Coarse Woody Debris in Boreal Forest

Coarse woody debris (CWD) volume and diversity are vital attributes of forest ecosystems. However, despite their importance, their long-term dynamics associated with fire- or logging-origin and overstory type have not been examined in boreal forest. We hypothesize that (1) CWD compositional diversity increases with stand development whereas CWD volume follows a U-shaped pattern. Furthermore, we attempted to test if (2) CWD volume and compositional diversity converge for postlogged and postfire stands through stand development, and (3) mixedwoods have more CWD volume and greater compositional diversity than conifer or broadleaf overstory types. We sampled 72 stands ranging in age from 7 to 201 years in fire-origin stands and 7–31 years in managed stands with conifer, mixedwood, and broadleaf overstory types in central boreal Canada. For fire-origin stands, snag volume was 100–260 m³/ha in 7-year-old stands, 5–20 m³/ha in 25-year-old stands, and 25–60 m³/ha in older stands; downed woody debris (DWD) volume decreased from 7 to 72–90 year-old stands, increased in 124- to 139-year-old stands, then either decreased or increased in 201-year-old stands depending on overstory type. CWD diversity increased from 25 to 124–139 year-old and plateaued, but in 7-year-old stands, CWD diversity was as high as that in the 124 and up year-old age classes. Logging resulted in a smaller amount and lower size variability of CWD in 7-year-old stands, with a larger portion being fast-decomposing Betula papyrifera. Most CWD characteristics had not converged by approximately 30 years since disturbance between the two stand origins. More diverse CWD occurred in mixedwoods, but conifer stands contained the greatest CWD volume except in 7 year-old postfire stands. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. B. W. Brassard collected and analyzed data and wrote the paper. H. Y. H. Chen conceived and designed the study, analyzed data, and critiqued earlier drafts of the paper.     

鼎湖山锥栗粗木质残体的分解和元素动态

选取锥栗(Castanopsischinensis)粗木质残体(coarsewoodydebris,CWD)的3个径级(径级1-3分别为5-10cm,10-20cm和20-30cm),并且将每个径级的锥栗粗木质残体分为Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ5个分解阶段。通过测定锥栗粗木质残体3个径级的Ⅰ-Ⅲ阶段的7种化学元素(C、N、P、K、Ca、Na、Mg)的浓度和CWD密度变化来研究其分解过程中的元素动态、分解速率及其分解过程中基质质量的变化。到分解阶段Ⅲ时,3个径级的重量与原来相比分别损失了36%、48%和43%。元素N、P、Mg、Ca、Na的浓度升高。元素N的累积可能和锥栗粗木质残体中寄生着固氮细菌和真菌有关。元素P、Mg、Ca、Na的浓度升高则可能是由于这4个元素因淋溶流失的速度小于锥栗粗木质残体质量的损失速度,造成元素积聚,元素C、K的浓度降低。N/P比值是较好的分解指示指标。虽然存在元素的净释放,但是由于C和其它主要元素的释放速率较慢,因而锥栗粗木质残体是森林中重要的C库和长期的元素来源。     

白马雪山国家级自然保护区典型森林生态系统服务

生态系统服务是近年来生态学研究的热点领域,对关键区域生态系统服务的研究具有重要意义.云南省白马雪山国家级自然保护区地处青藏高原南延部分,拥有独特的地理位置,是生物多样性保护的热点区域.本文对该保护区森林生态系统的生物量与生产力、水源涵养、营养物质循环等3项服务的功能量进行了评估.结果表明:保护区森林总生物量2215.86×104t,生产力171.84×104t·a-1;水源涵养量11964.56×104m3;N、P、K年吸收量分别为26025.94t、2638.57t、12016.85 t.研究表明,保护区森林生态效益显著,对于维持当地以及周边地区的生态安全具有重要意义.     

广东省七目嶂自然保护区的森林植被类型

广东省七目嶂自然保护区的森林植被主要由5个植被类型、15个群系和26个群丛组成。代表性植被类型为南亚热带山地常绿阔叶林,其优势科为壳斗科、樟科、茶科、金缕梅科、紫金牛科等,以热带亚热带区系成分占优势,现状植被有较强的次生性特点。马尾松林是常见的类型,它逐渐过渡到针阔混交林。