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1.
北京西山地区火烧迹地植被恢复研究   总被引:3,自引:1,他引:2  
在土壤性质分析的基础上,应用丰富度、多样性、相似度指标,研究了火烧迹地植被恢复情况,并与未过火林地做出了比较,讨论了北京西山地区火烧迹地土壤性质的变化与植被恢复之间的关系。结果表明:1)火烧迹地土壤的土粒密度增加,pH值呈上升趋势,土壤有机质减少,全氮增加,有机质的C/N比值在15左右。2)火烧迹地上植被的物种丰富度、Simpson指数、Shannon-Wiener指数高于未过火林地,火烧迹地与未过火林地更新层的物种丰富度相差不大,灌木层和草本层的物种丰富度和多样性则是火烧迹地上较高。3)火烧迹地与未过火林地土壤性质的差异导致了植被的差异,植被恢复也对土壤性质的变化产生了影响。  相似文献   

2.
对大兴安岭松岭林业局所辖的古源林场和绿水林场不同年代落叶松白桦林火烧迹地的植被恢复情况进行了调查,用α多样性对火烧后乔木层、灌木层、草本层进行评价。结果表明:物种多样性指数在火烧后表现为先增加后减小,然后急速增加,在火烧20a后除草本层多样性指数继续增加外,乔木层和灌木层逐渐趋于稳定状态;在火烧后4a之内乔木层物种均匀度指数降低,灌木层和草本层均升高;草本层的丰富度指数在火烧后变化较大,乔木层和灌木层由于受物种基数低而变化较小。  相似文献   

3.
以内蒙古大兴安岭兴安落叶松林火烧迹地为研究对象,采用分层取样的方法对群落中植被进行了调查,分析比较了不同火烧木管理方式下兴安落叶松林林下群落恢复过程中物种组成、多样性指数及地上生物量的差异。结果表明:火烧木择伐方式下火烧迹地与未火烧对照样地林下群落相似性最大。不同火烧木管理方式下,火烧迹地林下群落多个α多样性指数均表现为草本层灌木层的趋势。不同火烧木管理样地草本层Simpson和Shannon-Wiener指数均小于对照样地,而在灌木层都大于对照样地。3种不同类型火烧木管理方式火烧迹地恢复13年后,林下草本层生物量均小于对照样地,而灌木层生物量较对照样地相比都有不同程度的增加。  相似文献   

4.
采用群落空间序列推断时间系列的研究方法,对黑龙江省黑河地区重度火干扰后天然次生林结构变化和演替动态规律进行了调查研究。选择该地区广泛分布2个典型森林类型作为研究对象,即林分类型A和林分类型B。林分类型A是以白桦、山杨为优势树种组成的阔叶纯林或阔叶混交林,分布在坡度小于25。的低坡度区域;林分类型B是以蒙古栎、黑桦为优势树种组成的纯林或混交林,分布在坡度大于25。的高坡度区域。对火烧后这2种林分类型不同植被层(草本、灌木、幼树和乔木层)的物种丰富度、植被盖度、重要值和群落相似度进行了调查分析。研究结果表明:火干扰后林分类型A各层物种丰富度、盖度大于相应年度林分类型B;这2种林分类型的草本层和灌木层的物种丰富度和盖度都随火后年度的推移呈下降趋势,而乔木层呈上升趋势。通过对各层物种丰富度重要值的比较和群落结构变化分析,确定了林分类型A和林分类型B火烧后植被的演替动态过程。重度火干扰后80年,林分类型A演替趋势为白桦、落叶松混交林,灌木层以平榛、笃斯越桔为主,草本层以苔草、猴腿蹄盖蕨、红花鹿蹄草为主:林分类型B演替趋势为蒙古栎、黑桦混交林,灌木层以胡枝子、平榛为主,草本层以苔草、天门冬、小花萱草为主。图4表3参33。  相似文献   

5.
以内蒙古大兴安岭兴安落叶松林轻度火烧迹地为研究对象,采用分层取样的方法对群落中植被进行了调查,分析比较了不同恢复年份后兴安落叶松林群落各层物种组成及多样性的差异。结果表明:不同恢复年份后群落各层α多样性指数总表现为草本层﹥灌木层﹥乔木层的趋势。群落物种总数随着恢复时间的推移呈逐渐增多的趋势。这种变化趋势主要出现在草灌层内,而在乔木层内并不明显。群落草本层物种数除1996L以外,其它3个恢复年份均小于对照样地,而群落灌木层物种数除1996L与对照样地相当,其它3个恢复年份均大于对照样地。总体来看,轻度火干扰有利于植被的更新与演替。  相似文献   

6.
岷江上游人工油松林群落空间结构:物种丰富度和盖度   总被引:9,自引:0,他引:9  
在岷江上游油松人工林中调查了1hm^2群落空间垂直结构上的乔木、灌木和草本层的盖度和物种丰富度,以及2个100m长样带上的林窗斑块和油松斑块(冠幅相互连接的油松个体被合并为同一斑块)内部的群落水平结构变化。结果发现:群落的垂直空间结构上,乔木层(油松)盖度与灌木层盖度、林下总盖度(灌木和草本层的盖度和),以及林下物种丰富度(物种数量)成显著负相关,灌木层盖度与草本层成显著负相关。林下物种丰富度与总盖度呈显著正相关,但在灌木层和草本层内部,物种丰富度与盖度间没有显著相关性。水平空间结构上,随油松斑块增大,斑块内灌木层盖度下降,草本层盖度上升;物种丰富度约在油松斑块直径为12~15m时达到最大。在林窗内部,物种丰富度和灌木层盖度在林窗边缘高于林窗中央,而草本层盖度在林窗边缘较高。考虑到不同斑块大小支持不同物种的生存,岷江上游油松人工林应建立由不同大小的斑块(林窗和油松斑块)组成的镶嵌式群落.  相似文献   

7.
大兴安岭火烧迹地植被天然恢复效果的评价   总被引:2,自引:0,他引:2  
通过对大兴安岭新林林业局宏图林场3个不同火烧恢复时期森林植被恢复的调查,以火烧迹地内生物多样性为研究对象,应用主成分分析方法,对各调查区恢复情况进行分析。研究结果表明:火烧迹地各层物种数随火烧后恢复时间的推移,乔木层与灌木层的变化不是很明显,而草本层变化较大,随着时间的推移物种数逐渐降低;各层的物种多样性随火后恢复时间的推移先增加后减少,之后逐渐处于平稳;各层的物种均匀度随火后恢复时间的推移也是先增加后下降,之后逐渐处于平稳,其中波动变化最大的是灌木层,说明火干扰对灌木层空间分布影响较大。  相似文献   

8.
【目的】探究青藏高原东北边缘云杉-冷杉林火烧迹地植被恢复与重建过程中的灌木群落特征动态,阐明火烧迹地灌木群落多样性格局和维持机制的生态过程,为在火烧迹地恢复与重建过程中对植被进行合理干预、尽快恢复生态效益提供合理依据。【方法】以空间代时间方法,分析恢复5年和15年火烧迹地灌木群落和未过火林地林下灌木层物种组成特征、α物种多样性和β物种多样性。【结果】在5年、15年火烧迹地灌木群落与未过火林地林下灌木层之间,植物种类组成存在差异,5年火烧迹地共调查到11科17属24种,15年火烧迹地共调查到8科10属17种,未过火林地共调查到12科19属35种。5年、15年火烧迹地和未过火林地的物种丰富度指数与Pielou均匀度指数,以及5年火烧迹地的物种丰富度指数与Simpson指数、物种丰富度指数与Shannon-Wiener指数的相关性均不强(P<0.1或P>0.1),其他指数间的相关性均较强(P<0.001或P<0.01)。物种丰富度指数为5年火烧迹地>15年火烧迹地>未过火林地,Shannon-Wiener指数和Simpson指数均为15年火烧迹地>未...  相似文献   

9.
以山西省三交林场火烧迹地为研究对象,采用群落调查方法,分析了在自然更新下的不同植被恢复类型(油松人工林、灌木林、草本丛)下物种的组成及生物多样性。结果表明:(1)与对照相比,重度火烧后,草本丛的优势种重要值变化不明显,但喜阴耐旱的植物重要值显著升高;而灌木林主要以阳生耐旱草本植物占主要优势;油松人工林林分群落结构变化只是在灌木层和草本层中一些物种的更替。(2)重度火烧后所有植物的Simpson多样性指数均大于对照样地,油松人工林在重度火烧后多样性明显升高,油松人工林草本丛灌木林地。说明重度火烧2a后,不同类型植被恢复仍有一定的变化。  相似文献   

10.
丛燕  魏云敏 《林业科技》2011,36(3):54-56
采用空间序列代替时间系列的方法,对不同程度火烧迹地中阔叶林和白桦落叶松林生物量变化进行动态研究的结果表明:在中、重度火烧迹地中,灌木生物量曲线波动幅度剧烈,草本生物量曲线波动幅度较小,最后都逐渐趋于稳定;在轻度火烧迹地中,草本、灌木生物量开始阶段迅速增加,之后呈现较小幅度波动,最后逐渐趋于稳定。乔木生物量在轻、中、重度火烧迹地中都呈增长趋势;在阔叶林和白桦落叶松林两种林型的不同程度火烧迹地中,总生物量与火后时间具有较强的相关性。  相似文献   

11.
火干扰强度对兴安落叶松林物种组成及多样性的影响   总被引:3,自引:0,他引:3  
以大兴安岭地区兴安落叶松林为研究对象,采用群落调查方法,分析不同火强度对大兴安岭地区落叶松林物种组成及物种多样性的影响。结果表明,重度火干扰对兴安落叶松林物种组成影响较大,火烧迹地的演替从喜光、耐旱的草本及灌木开始,形成以草本层占主要优势的白桦灌草林群落;中度火干扰保留了少量的兴安落叶松,白桦萌条形成更新层和演替层,促进森林群落由针叶林向针阔混交林演替的过程;轻度火干扰不能改变原有的树种组成,林分群落结构变化只是在灌木层和草本层中一些物种的更替。随着火干扰强度的增加,落叶松林物种多样性指数和均匀度而呈现线性下降趋势,优势度呈现乘幂性上升趋势。  相似文献   

12.
柞蚕场封山育林对植被恢复的影响   总被引:2,自引:0,他引:2  
对柞蚕场、柞蚕场封山育林6a、9a的植被调查数据进行了分析,结果表明:柞蚕场封山育林可明显促进蒙古栎等乔木的生长和郁闭,但由于萌生,林木的水平分布多呈现聚集于母树的丛状分布;封育后由于林分郁闭,林内光照降低,灌木和草本植物的盖度有所减少;通过多样性指数测度,封育后乔木层、灌木层、草本层的多样性指数均高于柞蚕场;封育后由于森林凋落物的增加使枯落物存储量不断增加,可改善土壤肥力、提高林地涵养水分的功能.  相似文献   

13.
This study was done using the non brown fractal model to quantify and compare the variations in the species richness of trees, shrubs, herbs and all plants along an altitudinal gradient and to characterize the dominating ecological processes that determine the variations. Two transects were sampled far away from any anthropogenic disturbances along the shady slopes of the Dongling mountains in Beijing, China. Both transects were continuous and 2 m wide, and every individual tree and shrub was recorded in each of them. Discrete quadrats of 1 m × 1 m were located along the transects A and B for estimation of the herb species richness along the altitudinal gradients. The level interval between the quadrats was 10 m and 25 m respectively. In this study, transects A and B were combined into one transect AB, and 40 m was selected as the optimal quadrat length along the altitudinal gradients for measuring the plant species richness patterns. Species richness in each quadrat was calculated using a program written in Matlab 6.0. Direct gradient analysis was used to describe the overall trends in the species richness of trees, shrubs, herbs and other plants with change in altitude, while the non-brown fractal model was used to detect more accurately their variations at various scales along the gradient. The model assumed that each class of ecological processes affecting the distribution of a variable could be represented by an independent spatial random function. Generally, ecological phenomena are determined not by a single ecological process but by multiple ones. These processes act on ecological patterns within their own spatial scales. In the non-brown fractal model, the spatial random functions are nested within a larger range of spatial scales. The relative contribution of the spatial random functions to the spatial variation of a variable is indicated by a weighting parameter that has to be greater than or equal to zero. In this paper, we reached the following results and conclusions. Firstly, the direct gradient method describes the general trends of trees, shrubs, herbs and all plants along the altitudinal gradient but is unable to provide further details on the altitudinal variations in the species richness. The non-brown fractal model brought out the altitudinal variations in the species richness of trees, shrubs and herbs at various scales and related them to the ecological processes. The sharp changes in the double-log variograms suggest that the non-brown fractal model is suitable for characterizing the altitudinal patterns in the species richness of trees, shrubs and herbs at various scales but is not appropriate for explaining the variations in the plant species richness, since no significant changes were found in the double-log variograms in this case. Secondly, for the trees, the double-log variogram was divided into two scale ranges (0–245 m and 245–570 m), with a fractal dimension of 1.83 and 1.10, respectively, implying that changes in the tree species richness were random at small scales (0–245 m) and almost linear at large scales (245–570 m) along the altitudinal gradients. This suggests that altitudinal variations in the tree species richness are dominated by short-range processes at small scales and by long-range processes at large scales. Thirdly, for shrubs and herbs, the double-log variograms exhibited three ranges (0–101 m, 125–298 m and 325–570 m), and the fractal dimensions were 1.78 and 1.97, 1.56 and 1.43, and 1.08 and 1.25, respectively. The results indicate that, as in the case of trees, species richness of shrubs and herbs are distributed randomly at small scales and change in a linear manner at large scales although variations in the herb species richness is less heterogeneous than shrub species richness at large scales. These results also indicate that species richness of shrubs and herbs change approximately like brown movement at middle scales. The results also suggest that altitudinal variations in the specie richness of shrubs and herbs are dominated by three ecological processes, short-range ecological processes at small scales, long-range ecological processes at large scales, and brown fractal processes at middle scales. Interestingly, comparisons of the variations in the species richness of shrubs and herbs reveal that shrubs and herbs present the same scale range in spatial variation in species richness but display different trends in species richness along the altitudinal gradient, i.e. the shrub species richness decreased with increasing elevation whereas the herb species richness peaked at the mid-high elevation. These patterns suggest that although the scales at which the main processes affect patterns in species richness are the same, the processes are completely different, or the processes are similar but the responses of the shrubs and herbs to the ecological processes are different. Finally, the plant species richness did not show any obvious pattern along the altitude gradient and maintained a constant fractal dimension across all scales, this is perhaps because the processes defining the patterns of plant species richness had similar weights and acted over closely related scales. __________ Translated from Acta Phytoecologica Sinica, 2005, 29(6): 901–909 [译自: 植物生态学报]  相似文献   

14.
海南霸王岭热带山地雨林森林循环与群落特征研究   总被引:6,自引:0,他引:6  
以海南霸王岭1hm^2热带山地雨林的网格样方调查数据为基础,首先对全林分的群落特征进行了分析,然后以森林循环理论为指导,研究了热带山地雨林的种群与群落特征。结果表明:热带山地雨林中不同生活型的树种在利用垂直和水平生态资源上是相对分离的,绝大部分的灌木或小乔木树种的水平生态位宽度较大,垂直生态位宽度较小,中、大乔木则正好相反,而那些低密度、稀有种的生态位宽度最小。随森林循环过程的进行,各树种在不同阶段斑块内出现的频度也会发生相应的变化。霸王岭热带山地雨林中占优势的乔灌木树种大都呈聚集分布的格局,个体数中等的树种大都呈均匀分布的格局,而那些个体数少的低密度种则大都呈随机分布的格局。随着森林循环过程的推进,每个树种所拥有的个体数和所占据的面积是逐渐减少的。森林循环不同阶段内的树种数随着个体数的增加呈现出逐渐减少的总趋势,尤其是由单个体和双个体所对应的物种数较多,3个以上个体对应的树种数则呈现出明显的下降。不同斑块之间组成相似性的大小在一定程度上表明了热带山地雨林森林循环斑块动态的连续性,相邻阶段斑块之间的相似性大于不相邻阶段斑块。以森林循环阶段为基础计算的生态位宽度表明,热带山地雨林中大部分低密度的树种或只集中分布在森林循环的少数阶段斑块内的树种对不同阶段斑块的生态资源利用较少,而那些在森林循环的不同阶段都出现,且个体数或断面积中等的树种,对森林循环不同阶段斑块的生态资源利用较大。  相似文献   

15.
The effects of microhabitat (shrubs and herbs), plant litter, and seed burial on the regeneration of Liaodong oak (Quercus wutaishanica Mayr) and Chinese pine (Pinus tabulaeformis Carr.) were studied in three typical stands (Liaodong oak forest, Chinese pine plantation, and grassland) in the Loess Plateau, China. We monitored the establishment and growth of seedlings of these two woody species in sown experimental plots, in which shrubs and herbs, plant litter, and seed burial were manipulated. In the grassland, shrubs and herbs facilitated Liaodong oak establishment, with no effect on the establishment of Chinese pine. In the two forest stands, shrubs and herbs primarily had an inhibition effect on the establishment of these trees. The effects of plant litter were facilitation or inhibition, depending on the target species and the habitat. Seed burial had a positive effect on seedling establishment. In all three habitats, shrubs and herbs had inhibition effects on seedling growth of both tree species. Plant litter and seed burial did not influence seedling growth in either species. Liaodong oak and Chinese pine use different regeneration strategies during early stages of succession and similar strategies during late stages of succession.  相似文献   

16.
森林采伐是森林经营中的一个关键环节。采伐对树木天然更新的影响直接关系到森林的结构、组成及森林的可持续经营。本文以长白山阔叶红松林为研究对象,对择伐5 年后不同作业迹地(集材道、楞场和采伐后林窗)的幼苗更新及灌木、草本的多样性进行研究,并以没有进行采伐干扰的林地作为对照。共设计样地23 块,在各个小样地内调查幼树的种类、树木、高度;灌木和草本植物的种类、树木、高度和盖度,应用SPSS 软件进行一元方差分析。结果表明,择伐作业影响幼苗的更新,灌木和草本的多样性在作业迹地增加,尤其在林隙处的多样性最高。适当采伐能促进幼苗的更新,特别是阔叶树种的更新。集材道对幼苗密度的影响比对幼苗高度的影响大,幼苗密度在集材道上密度最高;采伐作业对针叶树种有严重的影响,在三种作业迹地上针叶树种的密度都比对照低。为了维持森林的结构和组成,在森林收获和楞场的建立时,必须采取科学措施保护针叶树种。此外,采伐林窗和楞场的面积都应该减小。为了确保采伐迹地建群树种的更新,经营中应该在保护生物多样性的前提下,适当控制过于旺盛的灌木和草本层的生长。本研究结果将为采伐后作业迹地的恢复和森林的可持续经营提供科学的依据。图1 表4 参14。  相似文献   

17.
Wildfire effects on understory shrubs and herbs, regeneration of the seedling and sapling size classes, and downed and dead fuels were assessed in a mixed conifer stand located in the Lake Tahoe Basin in which California white fir (Abies concolor var. lowiana [Gord.] Lemm.) was most abundant but with Jeffrey pine (Pinus jeffreyi Grev. & Balf.) also prevalent. In burned and unburned stand portions, prefire measurements served as a basis of comparison for the postfire measurements pertinent to each study component. Fire severely suppressed the understory vegetation, which was dominated by shrubs such as bush chinquapin (Chrysolepis sempervirens [Kellogg] Hjelmqvist) and antelope bitterbrush (Purshia tridentata [Pursh] DC.), while a tepid postfire recovery of most of the preexisting species in the burned stand portion was augmented by new ones, including shrubs such as snowbrush (Ceanothus velutinus Douglas ex Hook.) and whitethorn (Ceanothus cordulatus Kellogg) ceanothus and herbs such as Holboell's rockcress (Arabis holboellii Hornem.). Tree seedling abundance was also substantially reduced in the burned portion, but the postfire population was dominated by Jeffrey pine whereas white fir had been most prevalent originally. Sapling regeneration was eliminated from the burned stand portion regardless of species. Downed and dead fuel loading was severely diminished by the fire, especially regarding fine fuels, permitting subsequent sheet erosion to imperil new seedling regeneration. These results contribute to an understanding of the direction and pace of postwildfire succession on sites occupied by Sierra Nevada mixed conifer and similar forest cover types, which is critical in decisions concerning the need for, and extent of, postfire site rehabilitation measures.  相似文献   

18.
文章以北京市海淀区道路绿地作为研究对象,使用分层抽样的方法选出37条道路作为道路样本进行实地调查,分析了生长季植物配置、地表覆盖及影响要素,初步得到以下结论:1)海淀区道路绿地的植物配置以复合结构为主,两层以上配置方式绿地面积比例超过绿地总面积的80%,乔木+灌木的配置模式比较常见。草坪是不同类型道路绿地覆盖材料中的主要类型,其中草本花卉在复合地表覆盖道路绿地中也较为常见;2)海淀区道路绿地在生长季的灌草及地表覆盖率分别为80.89%和55.29%,但有近45%的道路绿地是裸土的;3)灌草覆盖率超过80%的绿地单元数量占绿地单元总数的47.37%,超过60%的绿地单元数量占绿地单元总数的63.74%,而地表覆盖率超过80%的绿地单元数量仅占绿地单元总数的9.36%,超过60%的绿地单元数量占绿地单元总数的20.47%;4)五环以外道路绿地地表覆盖状况最好,二环到四环随距离中心城区的距离增加而逐渐变差。行道树绿地的灌草及地表覆盖率最低,地表覆盖材料单一,而街头绿地裸土灌丛率最高。总体来看,海淀区道路绿地的地上植物配置主要是增加了灌草覆盖率,而地表土壤裸露状况没有得到明显改善。多数道路绿地存在"头上有绿荫,脚下有裸土"的问题。文章最后分析了造成海淀区道路绿地地表土壤裸露的原因,以及绿地管理存在的问题,并提出了生态养护等改进意见。  相似文献   

19.
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.  相似文献   

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