鼎湖山木荷(Schima Superba)粗死木质残体的分解研究

以鼎湖山国家自然保护区季风常绿阔叶林优势种之一木荷的粗死木质残体为研究对象,采用目前国际较认可的腐解等级划分方法,对木荷粗死木质残体3个腐解等级(Ⅰ、Ⅱ、Ⅲ)的密度及养分含量进行测定分析.结果表明:①木荷粗死木质残体的密度随腐解等级的增加从0.58 g/cm3下降到0.16 g/cm3,分解速率常数K值为0.144 7/a,在自然状态下,木荷粗死木质残体分解95%所需时间约为21 a;②粗死木质残体C/N比值随分解的进行先降后升而N/P则相反;③K、Ca、Na、Mg离子浓度随腐解等级的增加出现不同程度的增加,但增幅不明显.研究结果旨在为系统评估粗死木质残体的分解行为在生态系统养分循环中的作用提供基础数据.     

格氏栲天然林与人工林枯枝落叶层和粗木质残体有机化学组成研究

对福建省三明市格氏栲天然林及在其采伐迹地上营造的33年生格氏栲人工林和杉木人工林这3种林分的枯枝落叶层及粗木质残体物质化学组成进行研究．结果表明：在分解过程中3种林分枯叶和枯枝水溶性物质和纤维素含量不断下降,而枯枝中苯醇溶性物质和粗蛋白质含量有所上升．除半纤维素和纤维素外,3种林分粗木质残体水溶性物质、木质素和粗蛋白质含量均为L层〉F层,而苯醇溶性物质含量为L层〈F层．格氏栲天然林枯叶和枯枝水溶性物质、木质素、粗蛋白质、半纤维素和纤维素总贮量最高,而苯醇溶性物质总贮量以格氏栲人工林的最高．3种林分F层枯叶和枯枝有机物质的总贮量高于L层．与2种人工林相比,格氏栲天然林粗木质残体中各种有机物质贮量均最高．     

森林植被的水分自营作用及其观测试验论证方法

作为陆地生态系统的主体,森林对地表圈层的水循环产生了重要的影响,其涵养水源、防止水土流失和维持水质的作用为多数学者所公认,但是对于森林是否增加或减少河川径流量,在学术界还存在较大的争议.作者根据国内外学者在森林水文效应方面的观测结果和理论分析,提出了森林植被的水分自营作用理论.该理论认为,森林具有对环境的正向改造作用,森林植被通过对林区水分分布场的自主营造(改造)机制来增加林地的有效水分供应,改善林区的水文气象环境,创造出有利于森林植被生存的条件,同时引起河川径流量的增加或者降低.森林植被的水分自营作用理论比较好地综合了森林影响径流形成的各个因素,能够统一解释森林水文效应中相互矛盾的试验结果.为了更进一步地认识和完善该理论,为森林水文效应评价服务,还提出了验证该理论的野外观测试验方法,包括典型森林区辐射能量和水分通量的精细测量、森林流域分布式蒸散发计算模式研究、森林水分调节的主要环节及其计量标定、林地水分调节关系解析和森林生态系统水文过程模拟.     

Effects of Woody Debris on Channel Morphology and Sediment Storage in Headwater Streams in the Great Smoky Mountains,Tennessee-North Carolina

Coarse woody debris (CWD) is an important component of headwater streams, however, few studies have investigated the geomorphic effects of CWD in the southern Appalachians. In the Great Smoky Mountains, debris slides supply large volumes of CWD and sediment to low-order streams. This study investigates the effect of CWD on bankfull channel dimensions and in-channel sediment storage along second-order streams. Comparisons are made between streams that have experienced recent debris slides and those that have not. CWD channel obstructions are larger but less frequent along debris-slide-affected streams. Dendrochronological evidence indicates that CWD can remain in channels for over 100 yr. Relatively short residence times of CWD along debris-slide-affected streams suggest that logs are frequently flushed through these streams. CWD causes channel widening along all study streams, but the volume of sediment stored in the channel behind CWD obstructions is up to four times greater than the volume of sediment represented by bank erosion associated with CWD. Two large log jams formed by debris slides at tributary junctions stored approximately 4000 m³ of sediment. Sediment stored by CWD was finer than mean bed particle size, and thus represents a significant sediment source when CWD obstructions are breached.     

祁连山不同植被类型残体碳库贮量研究

采用野外调查测定、野外定位研究和室内分析相结合的方法,在植被类型变化较大林区,选择邻近相同海拔、坡向和土壤类型的天然林(青海云杉林、祁连圆柏林、高山灌丛林)、人工林(13 a华北落叶松)、牧坡草地和农田几种植被类型土壤为研究对象,研究了祁连山不同植被类型残体碳库贮量、组成与形成特征,结果表明:天然林残体碳总贮量为510.09~639.7 gC/m2,农田和草地分别为71.4 gC/m2和169.65 gC/m2,人工林为503.75 gC/m2。天然林地上残体碳年形成量为63.48~485 gC/(m2.a)、地下为267.8~314.3 gC/(m2.a),人工林地上为203.7gC/(m2.a)、地下为187.2 gC/(m2.a),农田地上为47.8 gC/(m2.a)、地下为106.4 gC/(m2.a),草地地上为98.3 gC/(m2.a)、地下为147.3 gC/(m2.a)。在不同植被类型中,从天然林到农田或草地,残体碳库贮量及形成量减小。     

干旱区森林水源涵养生态服务功能研究进展

论述了干早区森林水源涵养的机理、研究方法及研究现状，根据长期的定位观测资料分析干旱区森林对降水到径流过程的影响及对水分归宿的作用。认为干旱区森林水源涵养的生态功能在干旱区生态环境建设中具有重要作用。目前国内对干旱区森林涵养功能的分析仍偏重于定点定位观测，获取的资料以统计分析为主，在大尺度上建立定量预测模型及监控措施等方面还需作深入的研究。     

黄土丘陵半干旱区人工沙棘林水文特性及效益

沙棘是黄土丘陵半干旱区的主要生态-经济型树种，在生态环境建设中有重要作用。利用野外长期观测资料，系统分析了该区人工沙棘林的水文作用。结果表明：7～10a沙棘林冠平均年截留率为8．5％，林冠截留率(I)与郁闭度(C)关系式为I=-1．59 0．018C^1.439。5～10a沙棘林枯枝落叶层单次降雨可截留0．89mm降水。林地土壤入渗速率大于荒坡，其稳渗速率为1．5mm／min。林地土壤水分随季节变化明显，5月末0～500cm土层平均含水率为生长季最低，10月末最高。0～100cm土层是沙棘利用水分的主要层次，100cm土层是沙棘抵御持续干旱的主要层次。和荒坡比较，2～3a沙棘幼林减少产流的作用较小，产流量占荒坡的90．8％～99．5％，从4a起，产流量迅速减少，占荒坡的35．5％，10a沙棘林地的产流量为2．74t/hm^2，仅占荒坡的5．3％。林地产流量(Rs)与降雨量(P)和最大30min雨强(I30)密切相关，关系式为Rs=0．094P^0.603I30^0．610。     

Ecosystem Carbon Allocation of a Temperate Mixed Forest and a Subtropical Evergreen Forest in China

Ecosystem carbon allocation can indicate ecosystem carbon cycling visually through its quantification within different carbon pools and carbon exchange. Using the ecological inventory and eddy covariance measurement applied to both a mature temperate mixed forest in Changbai Mountain (CBM) and a mature subtropical evergreen forest in Dinghu Mountain (DHM), we partitioned the ecosystem carbon pool and carbon exchange into different components, determined the allocation and analyzed relationships within those components. Generally, the total carbon stock of CBM was slightly higher than that of DHM due to a higher carbon stock in the arbor layer at CBM. It was interesting that the proportions of carbon stock in vegetation, soil and litter were similar for the two mature forests. The ratio of vegetation carbon pool to soil carbon stock was 1.5 at CBM and 1.3 at DHM. However, more carbon was allocated to the trunk and root from the vegetation carbon pool at CBM, while more carbon was allocated to foliage and branches at DHM. Moreover, 77% of soil carbon storage was limited to the surface soil layer (0-20 cm), while there was still plentiful carbon stored in the deeper soil layers at DHM. The root/shoot ratios were 0.30 and 0.25 for CBM and DHM, respectively. The rates of net ecosystem productivity (NPP) to gross ecosystem productivity (GPP) were 0.76 and 0.58, and the ratios of ecosystem respiration (Re) to GPP were 0.98 and 0.87 for CBM and DHM, respectively. The net ecosystem carbon exchange/productivity (NEP) was 0.24 t C ha^-1 yr^-1 for CBM and 3.38 t C ha^-1 yr^-1 for DHM. Due to the common seasonal and inter-annual variations of ecosystem carbon exchange resulting from the influence of environmental factors, it was necessary to use the long record dataset to evaluate the ecosystem sink capacity.     

甘肃祁连山国家级自然保护区森林生态系统服务价值评估

森林生态系统服务价值评估对于人们全面认识森林生态系统服务功能及制定森林资源保护法规政策具有重要意义。依据《森林生态系统服务功能评估规范》（LY/T 1721-2008）、祁连山区森林生态系统定位观测数据、2008年森林资源调查数据及社会公共数据,对甘肃祁连山国家级自然保护区森林生态系统服务价值进行了评估。甘肃祁连山国家级自然保护区森林生态系统年服务价值总计为654.44亿元。按服务功能类型的价值比例从高到低排序为:保育土壤（46.59%）>生物多样性保护（25.53%）>涵养水源（14.03%）>固碳释氧（12.69%）>森林防护（0.50%）>积累营养物质（0.41%）>净化大气环境（0.24%）>森林游憩（0.01%）。按森林类型的价值比例从高到低排序为:灌木林地（63.7%）>有林地（34.1%）>疏林地（2.18%）。单位面积林地年均产生的生态系统服务价值为7.47万元·hm-2,其中,最大为有林地,其次是灌木林地,第三是疏林地。本文还对比分析了本次评估与以前较为全面的7次评估之间的差别及原因。     

九华山森林生态系统生态服务价值评估

基于LY/T1721-2008((森林生态系统生态服务功能评估规范>,采用实证研究、意愿调查、文献研究等方法,估算了九华山森林生态系统生态服务价值,结果表明:2009年,九华山森林生态系统生态服务价值为84 208.50万元,实物生产价值为4 359.06万元,生态服务价值是实物生产价值的19.31倍.各项生态服务功能价值大小顺序为:涵养水源>保育土壤>生物多样性保护>固碳释氧>森林游憩>净化大气环境>积累营养物质.可为九华山管委会制定旅游、社会经济发展规划,合理开发九华山生态旅游资源,提供理论依据和数据支撑,也可增强人们对九华山森林资源保护的自觉性和主动性.