我国森林生态系统枯落物现存量研究进展

在参考大量相关文献的基础上,对我国森林生态系统枯落物现存量研究进展进行了归纳总结。我国枯落物现存量的研究主要集中在亚热带和温带,热带相对较少;枯落物现存量的研究主要采用收获法,但取样样方的布设、面积、数量及取样时间等尚没有统一的规定;在大区域尺度上,气候是影响森林枯落物现存量变化的主导因子,不同气候带森林枯落物现存量的大小顺序为温带>亚热带>热带;森林枯落物现存量还受林分起源、群落组成和结构、群落发育阶段、土壤、地形条件及干扰的影响。文中还针对全球变化背景下我国森林枯落物现存量研究中存在的问题及今后的研究方向进行了探讨。     

不同龄组马尾松林凋落物量及养分归还量研究

对不同龄组马尾松人工林的年凋落物量、林地凋落物现存量及其元素含量和养分归还量进行分析测定，结果表明，从幼龄林至成熟林，马尾松林的年凋落物量为４．３９～１１．４３ｔ／ｈｍ２，林地凋落物现存量为４．９９～１３．４５ｔ／ｈｍ２，凋落物养分的年归还量为８７．７４～３５３．７１ｋｇ／ｈｍ２，林地凋落物养分的总贮量为１０１～２４８ｋｇ／ｈｍ２．这说明森林凋落物是一个庞大的养分贮存库，它对于维护林地地力，提高森林生产力具有重要的意义．     

大青山水源林不同森林类型生物量与水文作用的研究

按照不同森林类型分别对阴山山地东段大青山水源涵养林进行了生物量及其吸水量的测定分析。结果表明，白桦次生要的总体生物量最高，为２２８．７５ｔ／ｈｍ＾２；人工油松林为１１４．２ｔ／ｈｍ＾２；阳坡灌丛为３１．９ｔ／ｈｍ＾２；阴坡灌木林生物量最小，为２８．２ｔ／ｈｍ＾２。     

日本柳杉和杉木人工混交林生物量及生产力研究

从日本柳杉和杉木人工混交林生物量及生产力的研究结果表明：１６年生，密度为１７７０株／ｈｍ＾２的日本柳杉和杉木混交林，其两个树种的单株生物量分别可达到１５２．１０Ｋｇ和７３．７Ｋｇ。林分生物量达到２６８．００ｔ／ｈｍ＾２，其中乔木层生物量为２４８．０５ｔ／ｈｍ＾２（日本柳杉生物产量为２２８．１５ｔ／ｈｍ＾２，杉木１９．９０ｔ／ｈｍ＾２）占林分总生物产量的９２．７０％；草灌层总量为１０．２２ｔ／ｈｍ＾     

茂兰喀斯特森林主要演替群落枯落物的水文特性

对茂兰喀斯特森林两种主要演替群落——喀斯特原生乔木林和次生林枯落物的储量和水文特性进行了调查研究,结果表明:两种演替群落枯落物的平均总储量为4.77 t/hm2,喀斯特原生乔木林的总储量要高于次生林;两种演替群落之间,枯落物的最大持水率和最大持水量均为喀斯特原生乔木林高于次生林;枯落物不同层次之间,两种演替群落枯落物未分解层的最大持水率和最大持水量均高于半分解层;枯落物的持水量和吸水速率与浸泡时间分别存在明显的函数关系:V=a ln(t)+b和S=ktn;在自然状态下,茂兰喀斯特森林两种演替群落枯落物的平均有效拦蓄量为8.31 t/hm2,喀斯特原生乔木林的有效拦蓄量要高于次生林。     

梯形整地桉松混交林模式的水文生态功能

１９８２～１９９１年，对广西宜山县庆远林场不同整地方式及其不同植被类型的水文要素进行对比观测研究。结果表明，梯形整地桉松混交林模式具有显著的涵养水源、保持水土功能；与其他植被类型相比较，具有以下几点显著的差异：ａ．森林群落冠层的年截留水量为２３０．１ｍｍ，占降水量的１８．４％，比其他森林群落增加截留量１２．０％～５７．１％。ｂ．枯枝落叶层贮量及其最大持水量分别为７．７ｔ／ｈｍ２和２３．０ｔ／ｈｍ２，是其他植被类型的１．４～６．４倍。ｃ．土壤层的最大贮水量为５１１．５ｍｍ，比其他植被类型增加贮水６．６％～１１．８％。ｄ．林地水、土流失量分别为４．６ｍ３／（ｈｍ２·ａ）和０．６３ｋｇ／（ｈｍ２·ａ），比其他植被类型减少７９．０％～９７．９％。     

头塘山地圣诞树人工防护林群落的结构特征与生物生产力

对金沙江流域头塘山地圣诞树人工防护林群落的结构特征与生物生产力的研究结果表明：５年生的圣诞树人工林具有较高的生物量和生产力,其值分别为４２．００ｔ／ｈｍ＾２和８．３０ｔ／ｈｍ＾２．ａ。乔木根系生物量大,占乔木层总和物量的２９．１５％,且根瘤菌发达。     

杉木光皮桦混交林效益的调查研究

对桂西北杉木光皮桦混交林和杉木纯林的对比研究表明,３５年生杉桦混交林的立木蓄积量为４４１．０８７ｍ＾３／ｈｍ＾２,比杉木纯林高３．６％。混交林枯枝地层现存量及其Ｎ、Ｐ、Ｋ、Ｃａ、Ｍｇ五种元素的积累量分别为１３．１８ｔ／ｈｍ＾２和２９９．５ｋｇ／ｈｍ＾２,分别比杉木纯林高９．７％和６９．９％。８混交林地（０～１００ｃｍ）土壤容重为０．８１～１．２２ｇ／ｃｍ＾３,比杉木纯林低１．０％～８．０％,而土壤孔隙度,通气度和持水量分别比杉木纯林高２．０％～３．９％。土壤有机质、全氮、水解氮、有效磷和速效钾分别比杉木纯高５．５％～４９．８％。     

靖远哈思山森林植被水文效应调查与分析

对靖远哈思山的天然油松林、云杉林、阳坡灌木林、阴坡灌木林４个主要植被类型的林冠截留、枯落物、枯落物水容量、土壤渗透、土壤物理性质等因子进行了调查测定和分析。结果表明，该区植被类型的林冠对降水截留效果较好，截持率为２０％－３２％，枯落物的吸水量是它自身重的２－３倍；每公顷森林土壤的贮水功益效能为１３２３．８４－２０８５．６７ｔ，具有较好的水源涵养功能。     

人工针阔混交林功能和作用机理研究

通过对辽东、辽西人工针阔混交林中凋落物分解动态、防火防病虫机理、森林益鸟的流动频率试验及调查研究，结果表明，日本落叶松与色赤杨混交林枯落物年失重率大于日本落叶松纯林。枯落物（叶、技）年失重率，第１年纯林分别为混交林的７８．３％、７５．０％；第２年为８７．５％、８２．１％。各林型枯落物年失重率为慢－快－慢的节律，枯落物害羞元素的释放率是阔叶树种高于针叶树种。针阔混交林能提高分的防火、抗病虫能力，招引     

缙云山两种典型林分枯落物保水功能

通过对重庆缙云山两种典型林分（灌木林和常绿阔叶林）枯落物储量调查分析和枯落物持水特性的研究,得到不同林分类型下枯落物储量、最大持水量、最大吸水速率等水文特征参数.结果表明：灌木林枯落物储量大于常绿阔叶林（32.42 · hm-2＞25.48 ·hm-2）,灌木林最大持水量大于常绿阔叶林（2.30 mm＞1.36 mm,5.76 mm＞2.96 mm）,灌木林平均吸水速率大于常绿阔叶林（1.60 mm ·h-1＞0.86 mm ·h-1,4.02 mm· h-1＞1.61 mm· h-1）,灌木林日均蒸发量小于常绿阔叶林（0.22 · hm-2＜0.47 · hm-2）.灌木林和常绿阔叶林枯落物的保水性能均比较好,但灌木林要高于常绿阔叶林.     

塞罕坝机械林场地表可燃物类型划分与载量研究

对塞罕坝机械林场8个林分类型108个林班的地表森林可燃物组成、载量、含水率等进行了调查。结果表明落叶松成林和幼林、樟子松成林和幼林、针叶混交林、桦次生林等林分地表可燃物以枯落物为主,栎次生林和灌木林地表可燃物由枯落物与灌木组成,未成林地与草地可燃物以草本植物为主;地表可燃物载量依次为落叶松成林〉落叶松幼林〉针叶混交林〉樟子松成林〉樟子松未成林〉针阔混交林〉桦次生林〉樟子松幼林〉落叶松未成林〉灌木林〉栎次生林〉草地;草地与栎次生林的含水率最低,着火点也最低,火险危险程度最高;将现有林分按燃烧类型划分为5个类型20个亚类,全场地表可燃物总载量约为2．5×10^6t。     

Economic Benefit Analysis of Carbon Sequestration of Five Typical Forest Types in BeijingMiyun Watershed

This study provides basis information for estimating the feasibility of the environmental and ecological forestry construction project in the area. Through the survey in Miyun watershed, the economical benefits of carbon sequestration in five typical forest types have been studied by calculating the biomass from the timber accumulation data and converting to the money value. The results show that： in the duration of 100 years, at a discount rate of 5%, and 197 RMB yuan/t as the price of the carbon sequestration, the present value （PV） of the carbon sequestration in different forests are： 6900-9300 yuan/ha in Chinese pine forest,6100-8200 yuan/ha in oak forest, 4500-6100 yuan/ha in other broadleaf forests, 2300-3200 yuan/ha in shrubs and 1300-1800 yuan/ha in cypress forest. The annual mean economic benefit of carbon sequestration is 770-1040 yuan/ha. The pine forest has the highest carbon sequestration benefit, followed by oak forest, other broadleaf forest, shrubs, and cypress forest. If the land is suitable for all forests, pine forest and oak forest should be planted in order to sequestrate more carbon.     

滇东北4种典型筇竹林凋落物的持水性

以滇东北4种典型筇竹林为研究对象,对比分析不同类型筇竹林凋落物储量及持水性能,从而为滇东北筇竹林生态可持续经营提供理论依据和实践指导。研究结果表明,凋落物储量为人工筇竹-黄皮树混交林（7.61 t/hm²） > 天然筇竹-人工黄皮树混交林（6.61 t/hm²） > 天然筇竹-人工厚朴混交林（5.73 t/hm²） > 天然筇竹纯林（5.23 t/hm²）。凋落物最大持水量为天然筇竹-人工厚朴混交林（3.45 t/hm²） > 人工筇竹-黄皮树混交林（3.22 t/hm²） > 天然筇竹-人工黄皮树混交林（2.89 t/hm²） > 天然筇竹纯林（2.69 t/hm²）。4种类型筇竹林凋落物吸水速率均随着浸泡时间延长而逐渐趋于一致,筇竹混交林凋落物吸水速率高于筇竹纯林。凋落物的总有效拦蓄量为人工筇竹-黄皮树混交林（9.74 t/hm²） > 天然筇竹-人工厚朴混交林（8.95 t/hm²） > 天然筇竹-人工黄皮树混交林（7.73 t/hm²） > 天然筇竹纯林（6.23 t/hm²）。     

长江上游绵阳官司河流域低山丘陵区不同植被类型生物多样性分析

本文用多样性指数（Shannon—Wiener指数、Simpson指数）、均度指数（Pielou指数）、丰富度指数（Margalef指数、Menhinick指数）对绵阳官司河流域5种不同的人工林进行生物多样性分析,结果表明：经过植被恢复,各林分类型生物多样性都有所提高,同时水土保持效益也明显提高,土壤侵蚀量减少了42％;在5种植被类型中,乔木层中以针阔混交林的生物多样性最高,灌木层以松柏混交林和麻栎林的生物多样性最高,草本层以松柏混交林的生物多样性最高;5种植被类型中,灌木层地上部分生物量以针阔混交林最大为1849．37kg·hm^-2,马尾松纯林最小为747．37kg·hm^-2,其大小顺序为：针阔混交林〉柏木纯林〉栎类林〉松柏混交林〉马尾松纯林;草本层植物地上部分部总生物量大小顺序为：松柏混交林〉柏木纯林〉栎类林〉针阔混交林〉马尾松纯林。     

广东省西樵山不同林分类型枯落物持水特性的研究

对广东省西樵山4种不同林分类型枯落物进行的研究表明：1）4种林分类型枯落物总储量大小顺序为：生态林〉景观林〉珍贵阔叶林〉常绿阔叶林;2）4种林分类型枯落物持水量、持水速率与浸水时间的动态变化规律基本相似。持水量随浸水时间增加呈上升趋势,但当浸泡8h之后,趋势变缓;不同林分类型持水速率在0～2h最快,在4～6h后逐渐减缓,6h后明显减缓;3）不同树种林下枯落物有效拦蓄率范围为160．05％～182．57％,有效拦蓄量大小顺序为：生态林〉景观林〉珍贵阔叶林〉常绿阔叶林,枯落物的拦蓄量与枯落物总储量和枯落物的持水特性相关。     

Structure changes and succession dynamic of the natural secondary forest after severe fire interference

The structure and dynamic succession law of natural secondary forest after severe fire interference in recent 20 years were studied by adopting the method of deducing time series from the spatial sequence of vegetation in Heihe region, Heilongjiang, China. Two typical and widely distributed forest types in the study area, namely forest type A and forest type B, were selected as study subjects. Forest type A is pure broadleaf forest or broadleaf mixed forest mainly composing of superior Betula platyphylla and Populus davidiana in the area with gradient <25°, while forest type B is pure forest or mixed forest composing of superior Quercus mongolica and Betula davurica in the area with gradient >25°. Species richness, vegetation coverage, important value, and similarity index of community in different layers (Herb, shrub, small tree, and arbor layers) were investigated and analyzed for the two typical forests. The results show that after fire interference, the species richness and coverage in each layer in forest type A were higher than that in forest type B. Both for forest type A and B, with elapse of post-fire years, the species richness and coverage of herbs and shrubs showed a decline tendency, while those of arbor layer present a rising tendency. Through comparison of the important values of species in each layer and analysis of community structure changes, the dynamic process of post-fire vegetation succession for forest type A and B was separately determined. Post-fire 80 years' succession tendency of forest type A is B. platyphylla and Larix gmelinii mixed forest. Its shrub layer is mainly composed of Corylus heterophylla and Vaccinium uliginosum, and herb layer is dominated by Carex tristachya, Athyrium multidentatum, and Pyrola incarnate; whereas, the post-fire 80 years' succession of forest type B is Q. mongolica and B. davurica mixed forest. Its shrub layer is mainly composed of lespedeza bicolar and corylus heterophylla and herb layer is dominated by Carex tristachya, Asparagus densiflorus, and Hemerocallis minor.     

辽东山区不同森林类型土壤改良效益分析

辽宁东部山区是辽宁省浑河、太子河等主要河流的发源地和集水区,为辽宁省中南部工农业生产和人民生活用水提供保障。通过对该地区柞树林、杂木林、落叶松林、红松林、油松林等5种主要森林类型的林下枯落物层积累、土壤的物理化学性质等方面进行比较分析,研究结果表明:阔叶林在土壤改良、涵养水源方面较针叶林好,因此,在辽东山区营林时应多营建阔叶林或针阔混交林。     

灵空山主要森林类型枯落物生物量及持水性能

通过对太岳灵空山四种主要森林类型 :油松纯林、辽东栎林、松栎混交林、油落桦栎混交林的枯落物生物量及其持水性能的调查分析 ,总结出不同森林类型的生物量、最大持水量、分解率的大小排序。为研究森林的水土保持、水源涵养功能以及进一步综合评价该区的森林生态功能提供了科学依据     

Impacts of mixed litter decomposition from Robinia pseudoacacia and other tree species on C loss and nutrient release in the Loess Plateau of China

The productivity of Robinia pseudoacacia(R.p.) pure forest usually declines at the late growth stage,and reforming it into mixed forests could be a promising way to resolve this problem. When choosing a suitable tree species that can be mixed with R.p., the interspecific relationship is an important issue. Therefore, we gathered the autumn litter fall from R.p. and 10 other species from the Loess Plateau of China were mixed in dual species litterbags(R.p.+each other species) and buried them in soil for a 345 days lab decay incubation. We measured the litter mass loss and nutrient contents to determine whether the nutrient release was affected by mixed species litter decomposition. The impacts of mixed litter decomposition on macro-elements release were more obvious than on micro-elements. The litters with similar substrate quality might show variable impacts on nutrients release in mixed decomposition. The C loss and release of nutrient was improved by descending order when R.p. litter was mixed with Hippophae rhamnoides, Ulmus pumila, Populus simonii, Larix principis-rupprechtii and Quercus liaotungensis(Q.l.). But, except for Q.l., only the other species were recommended as suitable mix-plants for R.p. since promoting a high turnover of the nutrient in the litter compartment and a rapid availability for tree.