Long term cone production and growth responses to crown management and gibberellin A4/7 treatment in a young western hemlock seed orchard   总被引：1，自引：0，他引：1  

Stephen D. Ross 《New Forests》1989,3(3):235-245

At age 5–6 years, rooted cuttings in a western hemlock (Tsuga heterophylla) clonal seed orchard received either a severe (ST) or moderate (MT) top pruning (upper 50 and 25% of live crown removed, respectively), or were left untopped (UT). Over the following 6 years, UT trees increased in height from 1.5 to 3.9 m, whereas through annual and biennial top and side pruning, MT trees grew to 2.2 m and ST trees were maintained at 2.0 m. Crown pruning had no effect on the subsequent annual production of seed or pollen cones. Spray applications of gibberellin A_4/7 in years 2 and 4 of the study increased 5-fold and 2-fold the percentage of trees producing a medium and greater crop, respectively, of seed and pollen cones in each year 3 and 5.  相似文献   

澜沧江自然保护区云南铁杉林种子植物区系特征研究     

苏文苹  杨宇明  杜凡  王娟 《西部林业科学》2007,36(2):80-85

从科、属、种级水平上对澜沧江自然保护区云南铁杉林的种子植物区系特征进行了研究。结果表明:①该云南铁杉林与热带区系的联系以泛热带、热带亚洲成分为主,与温带的联系以东亚成分和北温带成分为主;在云南与滇西、滇西北的关系最为密切;在全国与西南地区关系密切,在东亚地区与中国—喜马拉雅地区最为接近。②经对该云南铁杉林种子植物科、属、种级水平上的热带分布与温带分布之比作分析,得出其群落具有亚热带向温带过渡的特点。  相似文献   

秦岭中段铁杉森林群落的定量分析     

彭鸿 《西北林学院学报》1992,7(1):57-63

通过10个样地的调查资料,分析了秦岭中段天然铁杉林的种类组成、多样性以及结构和演替趋势。用群落相似系数排队和聚类分析方法把铁杉林划分为4个类型,并通过主成分排序研究,指出湿度和坡向是铁杉林群落的环境制约因子。  相似文献   

光照条件对长苞铁杉种子萌发与幼苗生长的影响   总被引：4，自引：2，他引：2  

朱小龙  宋爱琴  王建林  黄承勇  赖志华  李振基 《福建林学院学报》2008,28(3)

2004-2006年研究了在不同光照下(100%,50%,25%,10%全日照)长苞铁杉(Tsuga longibracteata)种子萌发率、幼苗存活率、幼苗生物量及其分配比例和幼苗根与叶、生理特性。结果表明,50%全日照条件下,种子萌发率和幼苗存活率最高;幼苗根、茎、叶及总生物量最高;光照的增强促使生物量往地下分配以加强根部吸收水分的能力,并促使地上部分的生物量更多的分配到叶片生长上。随着光强的提高,幼苗叶片叶绿素a、叶绿素b、总叶绿素和类胡萝卜素含量均呈下降的趋势,叶绿素a与叶绿素b比值和类胡萝卜素与总叶绿素比值呈上升趋势。在光强不超过50%时,随着光强的提高,幼苗叶片和细根的MDA含量、SOD和POD活性呈升高趋势;光照强度达到全日照时,叶片MDA含量、SOD和POD活性呈下降趋势。幼苗叶片和细根Pro含量在25%全日照时最低。50%全日照附近是长苞铁杉育苗的合适光照强度。  相似文献   

生长光照环境对长苞铁杉幼树的影响   总被引：1，自引：0，他引：1  

朱小龙 《福建林学院学报》2008,28(2):136-139

2005年,在长苞铁杉纯林林冠下、小林窗(A<50 m2)、中等大小林窗(50 m2相似文献   

梅花山自然保护区长苞铁杉林特征研究   总被引：6，自引：3，他引：3  

邓元德 《福建林学院学报》2000,20(2):165-168

梅花山自然保护区长苞铁杉林是以长苞铁杉占绝对优势的针阔混交林 ,物种多样 ,林分蓄积量较高 ,为较典型的复层异龄混交林 ,群落学及测树学特征的研究能为长苞铁杉林的有效保护、及时更新及合理利用提供基础依据  相似文献   

Microbial communities in forest floors under four tree species in coastal British Columbia     

Susan J. Grayston  Cindy E. Prescott 《Soil biology & biochemistry》2005,37(6):1157-1167

We compare forest floor microbial communities in pure plots of four tree species (Thuja plicata, Tsuga heterophylla, Pseudotsuga menziesii, and Picea sitchensis) replicated at three sites on Vancouver Island. Microbial communities were characterised through community level physiological profiles (CLPP), and profiling of phospholipid fatty acids (PLFA).Microbial communities from cedar forest floors had higher potential C utilisation than the other species. The F layer of the forest floor under cedar contained significantly higher bacterial biomass (PLFA) than the F layer under the other three tree species. There were differences in microbial communities among the three sites: Upper Klanawa had the highest bacterial biomass and potential C utilisation; this site also had the highest N availability in the forest floors. Forest floor H layers under hemlock and Douglas-fir contained greater biomass of Gram positive, Gram negative bacteria and actinomycetes than F layers based on PLFA, and H layers under spruce contained greater biomass of Gram negative bacteria than F layers. There were no significant differences in bacterial biomass between forest floor layers under cedar. Fungal biomass displayed opposite trends to bacteria and actinomycetes, being lowest in cedar forest floors, and highest in the F layer and at the site with lowest N availability. There were also differences in community composition among species and sites, with cedar forest floors having a much lower fungal:bacterial ratio than spruce, hemlock and Douglas-fir. The least fertile Sarita Lake site had a much greater fungal:bacterial ratio than the more fertile San Juan and Upper Klanawa sites. Forest floor layer had the greatest effect on microbial community structure and potential function, followed by site, and tree species. The similarity in trends among measures of N availability and microbial communities is further evidence that these techniques provide information on microbial communities that is relevant to N cycling processes in the forest floor.  相似文献   

The effects of feeding by Oniscus asellus on leaf litter sulfur constituents     

C. R. Morgan  M. J. Mitchell 《Biology and Fertility of Soils》1987,3(1-2):107-111

Summary Feeding by the isopod, Oniscus asellus, produced changes in the sulfur constituents of leaf litter substrates (Acer negundo, A. saccharum, Fagus grandifolia, Picea rubens, and Tsuga canadensis). Isopod consumption of leaf litter generally accelerated the mineralization of carbon-bonded S and increased the formation of ester sulfate in all substrates. After the isopod egestion of A. negundo leaves, fecal decomposition over 6 weeks increased total S concentration from 68 to 120 mol S/g due to the catabolism of organic carbon. During the same period sulfate decreased from 34 to 20 mol S/g and carbon-bonded S increased from 34 to 100 mol S/g. Thus the total S pool in aged feces became enriched with organic S (83% of total S). Macroinvertebrate consumption accelerated the transformation of S constituents and the carbon-bonded S concentration approached that of the Oa organic horizon of a northern hardwood forest.Dedicated to the late Prof. Dr. M.S. Ghilarov  相似文献   

长苞铁杉林主要木本植物种类组成的局域分布哪   总被引：5，自引：1，他引：5  

吴承祯  廖成章  洪伟  钱莲文 《福建林学院学报》2002,22(3):193-196

对福建、广东、广西、贵州和湖南分布的长苞铁杉(Tsuga longibracteata)群落主要木本植物种类的局域分布进行研究.结果表明,分布区内的7个长苞铁杉群落木本植物有168种;组成上除长苞铁杉外,仅福建省的天宝岩、梅花山和大丰山长苞铁杉群落共有种为甜槠(Castanopsis eyrei)、木荷(Schima superba)和深山含笑(Michelia maudiae);各群落物种种数在前几位的科具有很大的相似性,集中在壳斗科(Fagaceae)、杜鹃花科(Ericaceae)、山茶科(Theaceae)和樟科(Lauraceae)等少数几个科;整个分布区内除长苞铁杉外没有共有种,群落与群落之间的偏宜种有33种,群落的特征种共有134种.  相似文献   

长苞铁杉林林隙内外群落多样性及稳定性   总被引：7，自引：1，他引：7  

钱莲文  吴承祯  洪伟  陈睿 《福建林学院学报》2005,25(3):202-205

采用Margalef丰富度指数(R)、Shannon-Wiener多样性指数(H)、Pielou均匀度指数(E)、均优多指数(Z)、生态优势度指数(λ)及群落优势度指数(C)分析长苞铁杉林林隙与非林隙物种多样性;用改进的M.Godron稳定性测定方法测定群落的稳定性.结果表明:长苞铁杉森林群落林隙以个体数为基础的Margalef丰富度指数(R)、Shannon-Wiener(H)指数及均匀度(E)明显高于非林隙各项物种多样性指数;以重要值为基础计算的Shannon-Wiener指数(H)及均优多指数(Z)也是林隙高于非林隙;林隙植物群落均优多指数(Z)显著高于非林隙,而生态优势度(λ)和群落优势度(C)又明显低于非林隙,表明林隙的存在增加了群落物种多样性,但同时也降低了群落的稳定性,且这一结果与M法所测的群落稳定性结果相一致,M法结果也表明整个森林群落处于典型的亚稳定状态.  相似文献