青钩栲人工林生态系统生产力的研究

青钩栲(Castanopsis kawakamii Hayata)是福建中亚热带区域性代表种。在我国除三明市莘口格氏栲天然林保护区有成片的青钩栲优势种群以外,其区域性分布仅呈零星少量。为了繁衍珍贵树种资源,推广多树种造林,莘口教学林场自60年代以来,人工成片驯化栽培珍贵树种达45个,计400ha之多。其中青钩栲人工林23年生蓄积量高达163m~3/ha,最大单株材积为0.922m~3(胸径42cm,树高18m)。是一个很成功的造林树种。研究青钩栲人工林生态系统的生产力,可对制定合理的营林技术措施提供一定的依据。     

天然格氏栲林乔木层种群种间关联性研究

格氏栲 (ＣａｓｔａｎｏｐｓｉｓｋａｗａｋａｍｉｉＨａｙａｔａ) ,也称青钩栲 ,属国家二级保护植物 ,是壳斗科常绿阔叶大乔木 ,是亚热带珍贵稀有树种之一 ,其自然分布范围狭窄 ,在我国主要分布于福建、台湾、广东、广西、江西等地区 ,多零星生长在海拔 2 0 0～ 1 0 0 0ｍ的丘陵地的常绿阔叶林中。但在福建三明小湖地区有近 70 0ｈｍ2以珍稀濒危植物格氏栲占优势的林分 ,多由百年以上的大树组成 ,是中国目前较为罕见稀有的天然群落。其原生植被受人干扰 ,现为天然次生植被。格氏栲林以其整齐林相、丰富的物种等独特的森林景观 ,自 1 958年…     

青钩栲育苗的几个问题

青钩栲又称格氏栲(Castanopsis Kawaka Miihag)为壳斗科栲属常绿大乔木,是我国南方一种速生珍贵用材树种。材质良好,宜于培育大材。同时,树型优美,果味可口,也是风景树和木本粮食树种。为了迅速发展这个树种,扩大栽培,几年来,福建林学院莘口教学林场小湖工区和西芹苗圃进行了青钩栲育苗试验,就育苗的几个主要问题小结如下。     

格氏栲自然保护区米槠种群直径结构规律研究

对福建三明格氏栲自然保护区的米槠林种群直径分布进行调查研究,应用5种概率分布规律对米槠、木荷、杉木、石栎4个主要树木种群的直径结构进行拟合,比较不同类型的拟合效果,分析其直径分布结构特征,预测各径阶株数,为该区域米槠林经营管理和森林调查等提供参考依据。     

福建三明格氏栲保护区优势植物种群竞争的初步研究

通过对三明格氏栲自然保护区中以格氏栲,马尾松和米储为优势的针阔混交林１０个样地进行调查,估算并比较各优势种群的竞争系数与Ｋ值比的关系。结果表明,耐阴的格氏栲和米槠种群将取代喜光的先锋树种马尾松种群;现存林分中格氏栲种群密度比米槠大,但随着种间竞争的进行,米槠将不断扩大种群密度,达到与格氏栲种群共存的竞争结果。这主要与各树种的生态学特性直接相关,另外也受到环境因素的影响。     

小湖格氏栲天然林生长的生态环境

<正> 格氏栲又名青钩栲(Astanopsis Kawakmii,Hay),是壳斗科常绿大乔木。树干通直,材质良好,果味可口,是一种速生珍贵用材和木本粮食树种。我国南方只少数省份有零星分布,三明小湖地区却发现大面积的单优群落。     

绿竹种群生物量结构研究

研究了闽南绿竹种群的生物量及其种群结构,研究结果表明;１．闽南纱竹种群的现存生物量为１５６０８．７６５ｆ／ｍ６２,其中地上部分为１３４４９．７２２ｇ／ｍ＾２,占８６．１７％;地下部分为２１５９．０４３ｇ／ｍ＾２,占１３．８３％。其各组分分别为：秆９１５１．９０２ｇ／ｍ＾２,枝２８１６．８００ｇ／ｍ６２,叶１４８１．０２０ｇ／ｍ６２,竹蔸１１９９．５４３ｇ／ｍ＾２,细根９５９．５００ｇ／ｍ＾２;２;     

格氏栲苗褐斑病的研究

<正> 格氏栲(Castanopsis kawakami)又名青钩栲,是珍贵的用材树种和经济树种。据报道,仅1943年日本人伊藤诚哉在我国台湾省发现过煤病(Meliola sbiiae yamam),甚今未见有新病害的报道。我院莘口教学林场小湖工区自从1977年人工采种育苗以来,由于褐斑病的为害,格氏栲育苗濒于失败。据几年来的统计,平均发病率高达95％,病情指数63.7-70.2。病株与健株相比,高生长下降63％。为解决格氏栲育苗中的病害问题,笔者从1979-1981年对病害进行了定点观察研究及防治试验,现报道如下。一、病害的症状病原菌以风雨传播,4月底至5月初格氏栲苗出土展叶时初次侵染嫩叶。叶面上出现水渍状针头大小的深褐色斑点,斑缘的叶绿体被破坏后,则形成淡黄色晕圈。当日平均温度20-25℃,相对温度80％左右时,病斑扩散很快,约15-20天就形成不规则的大斑,直径5-15     

黧朔栲人工林生长量的研究

用常规法对黧蒴栲人工林生物量进行了测定。研究结果表明，１３年和１０年生人工林的生物量分别为１６０．７５４ｔ／ｈｍ＾２和９４．７２５ｔ／ｈｍ＾２。乔木层各器官生物量为树干＞根＞枝＞叶；其生物量空间密度地上部分为５．３４７～８．１８４ｔ／ｈｍ＾２．ｍ。林木叶面积指数为６．５５＞８．１３ｍ＾２／ｍ＾２。树干年生物量随林龄增加而增大，１２年生达最大值１１．７３ｔ／ｈｍ＾２．ａ。     

湿地松人工林间伐强度效应分析

对赣东北中等立地上的两片６年和９年生,造林密度分别为２５００株／ｈｍ＾２和１１１０株／ｈｍ＾２的湿地松林分进行了间伐强度的对比试验５ａ后的结果表明,前者以１２７５株／ｈｍ＾２,后者以５２５株／ｈｍ＾２的保留密,可以显著提高林分的胸径和蓄积生长量,改善立木的径级结构,并能有效地缩短轮伐期。对湿地松林的初植密度和初次间伐龄进行了讨论,认为造林密度１５００ｒｉ     

格氏栲群落的结构特征

在 1hm2 样地调查材料的基础上 ,分析了福建三明格氏栲自然保护区森林群落的种类组成、群落外貌、水平结构和垂直结构特征。该群落共有维管束植物 1 1 0种 ,隶属于 42科 6 8属 ,其中单种属占 6 7% ,包括藤本在内的高位芽植物占总数的 87 3%。除格氏栲种群符合随机分布外 ,其它乔木种群均服从聚集分布 ,在垂直空间上可分为 3个亚层。物种多样性指数介于南亚热带季风常绿阔叶林和中亚热带常绿阔叶林之间     

广东莲花山白盆珠自然保护区吊皮锥群落特征*

采用样方调查法,对莲花山白盆珠自然保护区吊皮锥（Castanopsis kawakamii）群落的物种组成、属的地理成分、群落结构及种群结构特征进行研究。结果表明,在3个400 m2的主样方中,共记录了维管植物71种,隶属于32科45属,以茜草科（Rubiaceae）、樟科（Lauraceae）、壳斗科（Fagaceae）和山茶科（Theaceae）为优势科,以大节竹（Indosasa crassilfora）、吊皮锥和革叶铁榄（Sinosideroxylon wightianum）为优势种,吊皮锥种群均为中树或大树,林下缺乏幼苗小苗;在其他12个副样方中均未见到吊皮锥个体,反映了吊皮锥种群为衰退型。基于研究结果提出了吊皮锥资源保护及可持续发展的建议。     

Secondary forest floristic composition, structure, and spatial pattern in subtropical China

Secondary evergreen broadleaved forests are precious remnants for biodiversity conservation and templates for sustainable management of natural forests in subtropical China. Floristic composition, size structure, and spatial pattern of dominant tree species have been investigated for a subtropical secondary evergreen broadleaved forest in the Huitong Yingzuijie National Forest Reserve, Hunan, China. The location of all trees greater than 4 cm in diameter at breast height (DBH) were mapped within a 0.96-ha plot in which species, DBH, and total tree height were recorded. Ripley’s K(t) function was used to analyze spatial patterns and associations. The secondary forest consisted of 74 tree species and 1,596 stems per hectare. A reverse-J shaped DBH classes distribution was observed for all stems and trees of later seral species whereas trees of earlier successional species were distributed irregularly. Significant aggregated spatial patterns were observed for all trees within the forest and for conspecific trees of each dominant species. This result, and a repulsive spatial pattern for interspecific trees of Choerospondias axillaries and Cyclobalanopsis glauca against other dominant tree species, support segregation hypothesis. Contributions of seed dispersal, topographic heterogeneity, and competition to spatial patterns of conspecific trees vary depending on tree species. Attractive spatial pattern among interspecific trees of Liquidambar fortunei, Liquidambar formosana, and Pinus massoniana reflects stochastic colonization of pioneer tree species and a facilitation relationship. Although deciduous species are long-lived and persist over long successional processes, they will eventually be replaced by late seral evergreen species within the secondary forest if no disturbance events occur.     

广东象头山吊皮锥种群及其群落结构研究

吊皮锥（Castanopsis kawakamiiHayata）为我国特有的第三纪孑遗植物,稀有种。文章应用样方调查法分析了惠州市象头山吊皮锥种群结构及其所在群落的物种多样性。在1800m。的样方内,共记录了维管植物172种,隶属73科126属;胸径≥2．5cm的乔灌木层物种丰富度指数为8．39,Shannon—Wiener多样性指数为3．06,Pielou均匀度指数为0．80。该群落以樟科、壳斗科和山茶科为优势科,樟科植物种类最丰富,具有最高的重要值。重要值最高的树种为黄果厚壳桂（Cryptocarya concinna）,其次为荷木（Schimasuperba）、唐竹（Sinobambusatootsik）和硬斗稠（Lithocarpus hancei）。比较分析了黄果厚壳桂、阿丁枫（Altingia chinensis）、鼠刺（Iteachinensis）、硬斗稠、荷木、黄杞（Engelhardtiaroxburghiana）、马尾松（Pinusmassoniana）、吊皮锥的种群结构。结果表明,黄果厚壳桂和鼠刺的种群较大,但以Ⅰ～Ⅲ级苗和幼树为主,缺乏大径级林冠层大树;荷木种群也较大,但缺乏幼苗;吊皮锥和硬斗稠为稳定型种群;阿丁枫、马尾松和黄杞的种群较小,有少量林冠层大树,但缺乏幼苗,林下自然更新不良,为衰退种群。建议加强吊皮锥的种群动态监测和迁地保护研究,促进吊皮锥资源的保护和利用。     

Successional process of Picea crassifolia forest after logging disturbance in semiarid mountains: A case study in the Qilian Mountains,northwestern China

Selective logging is the most widely employed method of commercial timber production in Asia, and its impact on forest structure, composition, and regeneration dynamics is considerable. However, the successional processes in forest communities after logging in semiarid mountains are poorly understood. To provide more information on these processes, we used data from tree rings, direct and indirect age determinations, and field measurements of stand structure to reconstruct the historical disturbance regime, stand development patterns, and successional processes in a natural Picea crassifolia forest community in the Qilian Mountains of northwestern China. The results showed that the density of P. crassifolia forest increased significantly after logging. The densities of second growth forests 30 and 70 years after logging disturbance had increased to 2874% and 294% of primary forest's density, respectively. Logging disturbance did not alter tree species composition of logged stands. However, the diversity of understory species changed significantly among the successional phases. Logging disturbance decreased the spatial heterogeneity of second growth forest. The spatial distributions of recruitment were affected by the location of the remaining trees. There was less recruitment near the remaining trees than near forest that had been cut. In addition, logging disturbance also induced a growth release for the trees on the sites sampled. Our results imply that the succession and regeneration of P. crassifolia forest may be improved if the remaining trees could be retained relative uniform distribution pattern, thinning or selective logging could be performed to height density, exotic shrubs could be removed or the shrubs cover could be reduced during the earlier successional stages.     

不同密度杉木幼林系统生产力和生态效益研究

杉木幼林系统是由４个不同密度级处理系列小区组成,栽植密度为１６６５、３３３０、４９９５和６６６０株／ｈｍ＾２（以下分别用Ａ、Ｂ、Ｃ和Ｄ代替）。这些小区土壤质地及地形别无二致,都是用１年生实生苗１９８７年春天定植。８年生时调查了这些幼林系统林木生长、冠层厚度、枝下高以及生态效益等。随着密度由Ａ增加到Ｄ：平均胸径生长量从８．１ｃｍ降到６．６ｃｍ;平均树高生长量由５．９ｍ降至５．４ｍ;平均冠层厚度自４．     

光皮桦天然林群落特征研究

光皮桦 (Ｂｅｔｕｌａｌｕｍｉｎｉｆｅｒａ)为桦木科落叶大乔木 ,具有生长快、适应性强、材质好、用途广、落叶量大、繁殖容易等特点 ,是一种极有推广前途的优良速生用材树种。由于材质致密坚韧 ,是室内装璜的优质用材。近几年来对天然林过度采伐 ,使得光皮桦天然林资源锐减 ,而人工造林并未引起重视 ,使光皮桦处于渐危状态。为此 ,通过对福建邵武光皮桦天然林进行群落学分析 ,以期为保护光皮桦天然林和推广光皮桦人工造林提供理论依据。1　研究地点与方法调查地点位于福建省邵武二都村天然阔叶林 (东经 1 1 7°59′,北纬 2 7°44′) ,该片…     

华山松大小蠹带菌部位及贮菌器结构研究

研究了秦岭林区华山松大小蠹带菌部位及贮菌器结构,结果表明：华山松大小蠹成虫具有前胸背板体壁凹陷和刺毛构成的贮菌器,用于携带和传播真菌,其所携带真菌种类以穿孔细帚霉和小线嘴壳为主,以真菌孢子为唯一携带方式,并在在虫入侵健康寄主华山检针携带真菌孢子接种于华山松木质部。华山松大小蠹消化道内不具有含菌细胞和特化的带菌结构,消化道内存在的真菌也没有菌丝发育形成的附着孢或吸盘结构,使真菌不能被有效地贮存或携带     

Assessing rates of forest change and fragmentation in Alabama,USA, using the vegetation change tracker model

Forest change is of great concern for land use decision makers and conservation communities. Quantitative and spatial forest change information is critical for addressing many pressing issues, including global climate change, carbon budgets, and sustainability. In this study, our analysis focuses on the differences in geospatial patterns and their changes between federal forests and nonfederal forests in Alabama over the time period 1987–2005, by interpreting 163 Landsat Thematic Mapper (TM) scenes using a vegetation change tracker (VCT) model. Our analysis revealed that for the most part of 1990 s and between 2000 and 2005, Alabama lost about 2% of its forest on an annual basis due to disturbances, but much of the losses were balanced by forest regeneration from previous disturbances. The disturbance maps revealed that federal forests were reasonably well protected, with the fragmentation remaining relatively stable over time. In contrast, nonfederal forests, which are predominant in area share (about 95%), were heavily disturbed, clearly demonstrating decreasing levels of fragmentation during the time period 1987–1993 giving way to a subsequent accelerating fragmentation during the time period 1994–2005. Additionally, the identification of the statistical relationships between forest fragmentation status and forest loss rate and forest net change rate in relation to land ownership implied the distinct differences in forest cutting rate and cutting patterns between federal forests and nonfederal forests. The forest spatial change information derived from the model has provided valuable insights regarding regional forest management practices and disturbance regimes, which are closely associated with regional economics and environmental concerns.     

马尾松林下套种阔叶树的凋落物生态学研究 Ⅳ.凋落物的周转时间

在马尾松林冠下分别套种火力楠、拉氏栲、青栲、闽粤栲、格氏栲和苦槠,形成针阔混交异龄林模式,通过对各林分凋落物的研究表明,上述6个混交林群落及马尾松纯林的林地凋落物现存量变化在3988 0～9269 8kg·hm-2之间,而年凋落量范围为2853 0～7078 0kg·hm-2。基于对凋落量积累和分解速率的比较分析,可预测上述7个群落的凋落物周转时间依次为1 15、0 76、1 42、0 97、1 17、0 84及1 52a。对凋落物各组分的进一步分析表明,枯枝的周转时间明显大于枯叶,且马尾松的枯叶和枯枝的周转时间分别相应大于与其混交的阔叶树。