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1.
广西亚热带落叶阔叶林的分类系统及其管理   总被引:15,自引:2,他引:13  
广西亚热带落叶阔叶林是亚热带地区几类顶极群落遭受破坏后恢复过程的一个演替阶段,类型多种多样。本文研究制定了它的分类系统,包括2个亚群系纲、10个群系组、27个群系和77个群丛,扼要地阐述了它们的地理分布和生境特点,为其科学的管理提供基本依据。  相似文献   

2.
广西光皮桦林的分类和演替   总被引:10,自引:1,他引:9  
王献溥  孙世洲  李信贤   《广西植物》1998,18(2):123-138
光皮桦林是常绿阔叶林或山地常绿落叶阔叶混交林遭受砍伐后,在保护较好的情况下自然恢复起来的一种演替系列群落,属亚热带落叶阔叶林的一种类型。本文通过群落分类研究,划分出3个群丛纲和11个群丛。从这些群丛的外貌、结构和种类成分的变化,可确定其演替的趋向和所处阶段,是合理经营管理它的科学依据。  相似文献   

3.
森林凋落物(litterfall)是森林植物在其生长发育过程中新陈代谢的产物, 在物质循环和能量流动方面起着重要作用。该文利用已发表的我国主要森林凋落物的研究数据, 分析了不同组分(叶、枝和繁殖器官)凋落物量之间及其与总凋落物量之间的异速比例关系。结果表明: 我国森林叶、枝和繁殖器官的平均凋落物量分别为3 810.34、1 019.07和767.95 kg·hm-2·a-1; 温度、降水量、林龄对森林凋落物量均有一定程度的影响, 其中温度对各组分凋落物量的影响最大。叶凋落物量(LL)与总凋落物量(LT)之间呈等速生长关系(LLLT0.96), 繁殖器官和枝的凋落物量(分别为LPLB)与LT之间呈异速比例关系, 分别为LPLT1.84LBLT1.61。不同组分凋落物量之间具有显著的异速比例关系, 其异速指数均小于1.0。不同林型(常绿林和落叶林)各组分凋落物量之间的异速比例关系无显著差异。了解不同组分凋落物量与总凋落物量之间的异速比例关系可以为更加精确地估算森林生产力提供理论依据。  相似文献   

4.
1 Changes in a population of Ulmus glabra in Lady Park Wood (UK), a mixed deciduous native woodland, were studied by means of permanent transects. All individuals reaching 1.3 m height were recorded at irregular intervals from 1945 to 1993.
2 Dutch elm disease struck this population in about 1972. Most of the canopy and subcanopy stems were killed, but a few, slow-growing, subcanopy individuals survived unscathed.
3 Subsequent seedling regeneration and growth of sprouts from rootstocks of infected trees was substantial and vigorous. Twenty-three years after the outbreak of disease the number of elm individuals had increased by about 40%. Disease has, however, continued to afflict vigorous, exposed individuals.
4 The large-scale distribution of elm has been unaffected, but the small-scale pattern has changed due to the concentration of seedling regeneration in gaps.
5 The elm population appears to be differentiating into (i) a large high-turnover subpopulation of fast-growing, but repeatedly diseased maiden individuals and sprouts, and (ii) a small, low-turnover subpopulation of slow-growing individuals rooted in suboptimally dry, secluded sites.  相似文献   

5.
6.
森林的常绿、落叶特征是土地覆被产品的重要属性。由于山区地形复杂,地表遥感辐射信号地形效应明显,导致山区森林常绿、落叶特征遥感自动识别一直是难点。提出了一种基于阈值法的山区森林常绿、落叶特征遥感自动识别简单实用方法。该方法利用多源、多时相遥感影像,选择归一化植被指数(NDVI)为指标,通过统计参考样本的NDVI在生长季和非生长季的差异,自动找出区分常绿、落叶特征的阈值,基于判别规则识别山区森林常绿、落叶特征。以贡嘎山地区为例,分别以多时相Landsat TM影像(简称TM)、多时相环境减灾卫星影像(简称HJ)为单源数据,多时相的HJ、TM组合影像为多源数据,验证该方法的有效性。实验结果表明,该方法能够有效识别山区森林常绿、落叶特征,总体精度达到93.87%,Kappa系数为0.87。该方法适用于山区大面积森林常绿、落叶特征遥感自动提取,已被成功应用于"生态十年"专项西南地区土地覆被数据的生产。  相似文献   

7.
广西落叶栎林的分类研究   总被引:4,自引:0,他引:4  
王献溥  李俊清   《广西植物》1999,19(4):323-333
广西的落叶栎林属亚热带落叶阔叶林的一个群系组, 常见有栓皮栎林、麻栎林和白栎林3 个群系。主要论述其类型划分和生境特点, 为其经营管理和合理利用提供基本材料和依据。  相似文献   

8.
We describe liana diversity and variation in morphology of flowers and diaspores in two tropical forests in Mexico: a seasonally deciduous forest at Chamela, Jalisco and a lowland rain forest at Chajul, Chiapas. Flowers were classified as inconspicuous (1 cm in length and white or pale green flowers) or conspicuous (> 1 cm and brightly colored flowers). Dispersal syndrome was classified as anemochory, barochory, and zoochory. We recorded a higher number of lianas species in Chajul (128 spp.) than in Chamela (71 spp.). In both sites, families with the highest number of species were Bignoniaceae, Leguminosae, Sapindaceae, and Malphigiaceae, and almost half of the liana species had inconspicuous flowers. Most of the species had an abiotic syndrome of dispersal with 40 (56.3%) and 71 (55.5%) wind-dispersed species in Chamela and Chajul, respectively. Zoochory was significantly associated with inconspicuous flowers and anemochory with conspicuous flowers. Our results suggest that (1) flower morphology and dispersal type are not related with the amount of rainfall and (2) lianas are more prone to be wind-dispersed.  相似文献   

9.
暖温带落叶阔叶林动态变化的模拟研究   总被引:3,自引:0,他引:3  
桑卫国 《生态学报》2004,24(6):1194-1198
用森林动态林窗模型 FORET1模拟了暖温带落叶阔叶林的长期变化特征。模型参数取自暖温带地区长期森林研究和经营的历史数据 ,对过去数据中缺少的参数进行了实地测定 ,并用观测的数据对模型作了检验。结果表明模型能较好地模拟暖温带落叶阔叶林的长期动态变化特征。通过模拟可以看出 ,森林的净初级生产力没有明显变化规律且极度不稳定 ,峰值出现在30 a左右 ,相似于世界上其它地区森林动态格局变化 ,生物量格局呈循环状态变化 ,循环周期大致在 110 a左右。  相似文献   

10.
滇南榆绿木群落的初步研究   总被引:9,自引:1,他引:9  
滇南小橄榄坝地区的榆绿木(Anogeissus acuminata)群落是一种次生性质的单优群落,具有典型热带季雨林的外貌和结构特征。该群落是原生植被混交落叶季雨林破坏后发展起来的。  相似文献   

11.
两种温带落叶阔叶林降雨再分配格局及其影响因子   总被引:8,自引:0,他引:8  
孙忠林  王传宽  王兴昌  张全智 《生态学报》2014,34(14):3978-3986
林冠对降雨的再分配是森林生态系统的重要生态水文过程,影响着生态系统生物地球化学循环。于2012年5—10月连续测定帽儿山森林生态站的两种温带天然次生林型——蒙古栎林和杂木林的林外降雨、穿透雨及树干径流,旨在量化其降雨再分配过程及其影响因素。结果表明:蒙古栎林的平均穿透雨、树干径流、林冠截留分别占同期林外降雨的76%、7%和17%;杂木林分别占85%、5%和10%。根据模型估算,当降雨量分别超过1.0mm和0.7mm时蒙古栎和杂木林开始出现穿透雨;当降雨量超过3.0mm开始出现树干径流。当降雨量超过5.6mm,树干径流体积会随着树木胸径的增加而显著增加;而当降雨量低于5.6mm则出现相反趋势。穿透雨、树干径流及林冠截留的绝对量均随降雨量的增大而显著增加,但其占降雨量的比例却表现出不同的变化趋势。穿透雨量的空间变异随降雨量和降雨强度的增大显著减小。两种林型的降雨再分配格局因受降雨量、降雨强度等降雨特征和林冠结构的影响而产生差异。  相似文献   

12.
Abstract. 1. The seasonal distribution of macrolepidopteran species richness on Finnish deciduous trees vaned from positively skewed (peak in spring) to negatively skewed (peak in autumn).
2. The skewness values of species richness had a significant negative correlation ( r = - 0.98) with the duration of the seasonal shoot-growth period of the tree species.
3. Trees which complete their shoot growth early in the season ( Quercus type) produce new leaves only during spring, while trees whose shoot growth continues to autumn ( Populus type) do so throughout the summer.
4. Consequently, there is a difference in the number of available resources in the late summer foliage of different tree species, Trees ceasing leaf production early such as oak ( Quercus robur ) and bird cherry ( Prunus padus ) have one major resource type (mature leaves) in late-season foliage while trees like birches and alders have two Ooung and mature leaves).
5. Because young leaves formed late in the season are preferred to mature ones by some species of herbivores and because other species prefer mature leaves at the same time, the species richness of Populus-type trees is higher later in the season than the species richness of Quercus-type of trees, which have just one type of resource available.  相似文献   

13.
The leaves of woody plants at Harvard Forest in Central Massachusetts, USA, changed color during senescence; 70% (62/89) of the woody species examined anatomically contained anthocyanins during senescence. Anthocyanins were not present in summer green leaves, and appeared primarily in the vacuoles of palisade parenchyma cells. Yellow coloration was a result of the unmasking of xanthophyll pigments in senescing chloroplasts. In nine red-senescing species, anthocyanins were not detectable in mature leaves, and were synthesized de novo in senescence, with less than 20µg cm–2 of chlorophyll remaining. Xanthophyll concentrations declined in relation to chlorophyll to the same extent in both yellow- and red-leaved taxa. Declines in the maximum photosystemII quantum yield of leaves collected prior to dawn were only slightly less in the red-senescing species, indicating no long-term protective activity. Red-leaved species had significantly greater mass/area and lower chlorophylla/b ratios during senescence. Nitrogen tissue concentrations in mature and senescent leaves negatively correlated to anthocyanin concentrations in senescent leaves, weak evidence for more efficient nitrogen resorption in anthocyanic species. Shading retarded both chlorophyll loss and anthocyanin production in Cornus alternifolia, Acer rubrum, Acer saccharum, Quercus rubra and Viburnum alnifolium. It promoted chlorophyll loss in yellow-senescing Fagus grandifolia. A reduced red:far-red ratio did not affect this process. Anthocyanins did not increase leaf temperatures in Q.rubra and Vaccinium corymbosum on cold and sunny days. The timing of leaf-fall was remarkably constant from year to year, and the order of senescence of individual species was consistent.  相似文献   

14.
山西霍山落叶阔叶林边缘效应的研究   总被引:7,自引:1,他引:6  
通过对山西霍山暖温带森林植被片断化后不同地带不同群落边缘的边缘植被的调查,运用Shannon-Wiener物种多样性指数(D),Simpson生态优势度指数(C),边缘效应强度指数(Z)和各层次各物种的重要值(IV),对霍山暖温带落叶阔叶林的边缘效应进行了初步的研究。研究表明:(1)在群落的各种边缘区,边缘具有增大物种多样性的作用.(2)距林道边缘10m左右,物种多样性指数呈一峰值,10m以后指数逐渐降低并趋于平缓,在距自然空地5~10m处是物种多样性指数最高的地段,随后,随进入林内而逐渐减少并趋于平缓,在人工林的交错区内是物种多样性指数的高峰段,随后进入林内逐渐减少。距灌木丛交错区10m以后物种多样性指数出现高峰,随后逐渐减少并趋于平缓.(3)连翘、羊胡子草等植物是群落的优势种,且大多呈连续分布。  相似文献   

15.
Summary The paper reports on the relationships between vegetation and climate in the Upper Catchment area of Narmada river in Central India. The study site was divided into four ecoclimatic zones based on the classification of Thornthwaite & Mather (1955). While no clear-cut relationships could be established for the subordinate species and climate, the leading dominant species showed interesting relationships. Zones A, B and C show a humid type and support forest dominated byTectona grandis, Dendrocalamus strictus andTerminalia alata. In contrast,Tectona grandis is totally absent in Zone D which falls in a dry sub-humid type.Dendrocalamus strictus forms a second storey species at all places whereTectona grandis is the leading dominant, because the former is not a shade tolerant plant. Growth of the dominant species vary from zone to zone with changes in precipitation, potential evapotranspiration, soil moisture surplus and altitude. With topographical changes the growth of the dominant species changes.Tectona grandis shows maximum growth values on tops of hills only because of their inaccessibility to man so that no disturbances due to illicit felling, shifting cultivation and a host of other disturbances occur. The exiting forest crop is the remnant natural wealth which is the net result of interactions between climate, soil conditions and anthropogenic pressure.Nomenclature follows Raizada (1958).The author gratefully acknowledges the painstaking training in the computation of water balances given to him by Professor V. P. Subrahmanyam and Dr. B. Subba Rao of the Department of Climatology, Andhra University, Waltair (India). Most of the work presented here is the result of prolonged and consistent discussions with my teacher, Professor S. C. Pandeya, Head of the Department of BioSciences, Saurashtra University, Rajkot, India, for which I am indebted. Financial assistance was provided by the Council of Scientific and Industrial Research, Government of India, in the form of a Senior Fellowship.  相似文献   

16.
东灵山地区落叶阔叶林长期动态的模拟   总被引:3,自引:1,他引:3       下载免费PDF全文
用林窗模型研究了暖温带辽东栎林的长期动态变化。用森林经营历史和实际调查数据求得模型的参数。经过与实际数据检验证明所得模型能合理地预测辽东栎林的物种组成动态变化。通过对辽东栎交生裸地的模拟,可以得到:辽东栎种群在森林动态变化过程中呈现波动的形式,波动的周期为110a左右,叶面积指数的动态变化过程与林分的竞争状况有密切的关系,生产力的变化有着明显的无规律性,变化极水稳定,在30a进有一个变化的高峰期,  相似文献   

17.
We studied selected leaf traits [leaf area (LA), leaf water content (LWC), leaf fresh weight (LFW), leaf dry weight (LDW), specific leaf area (SLA) and chlorophyll content] of eight woody species (Shorea robusta, Buchanania lanzan, Diospyros melanoxylon, Lagerstroemia parviflora, Lannea coromandelica, Terminalia tomentosa, Holarrhena antidysenterica and Lantana camara) dominant at four sites in a dry tropical deciduous forest over complete two annual cycles (2008–2010). Our results showed that leaf traits varied across species (1.7–11.5 fold), months (1.2–1.5 fold) and sites (1.1–1.3 fold). However, leaf traits showed smaller variation between sites than between species. Leaf lifespan varied from 7 months (L. coromandelica) to 12 months (S. robusta). On the same sites, species differed in the length of deciduous period. The maximum LA, LDW, LFW and LWC were recorded for the semi-evergreen species, SLA for long-deciduous species and chlorophyll content for short-deciduous species, respectively. The coefficient of variation was maximum for LDW and minimum for chlorophyll content. Among the eight woody species, T. tomentosa exhibited the greatest LA, LDW, LFW and LWC. LA, LWC, LFW, LDW, SLA, LD, SD, MD & SE confirm.  相似文献   

18.
广西的南桦林和西桦林及其演替趋向   总被引:3,自引:0,他引:3  
在亚热带地区,当常绿阔叶林或山地常绿落叶阔叶混交林被砍伐后,桦木常常迅速侵入并发展成林,构成亚热带落叶阔叶林的一种重要类型,在自然发展过程中,它们又将向原来的森林类型恢复和演变。本文重点介绍了广西南桦林和西桦林的一些群落类型及其演替替向、期待发挥它们在林业建设中应有的作用。  相似文献   

19.
We investigated the patterns of soil nitrogen (N) and forest floor light availability, forest structure and tree species distribution along a topographic gradient on a 200-m mountain slope in a cool-temperate deciduous broad-leaved forest in Japan. Rates of soil N mineralization and nitrification decreased from lower to upper slope positions, revealing that N availability decreased up the slope. Maximum tree height and above-ground biomass were greater on the lower than the upper parts of the slope. Canopy openness, an index of light availability at the forest floor, increased up the slope. Tree species could be placed into three groups according to their distribution patterns on the slope. Ridge and valley species were distributed on the upper and lower parts of the slope, respectively, whereas uniform species were distributed over the entire slope. Topography-mediated resource gradients of soil N and light may be important determinants of species distribution patterns and forest regeneration, and the results of this study imply that the determinants of the regeneration process differ between the lower and upper parts of a slope. The former may be relatively light limited and the latter may be soil N limited. Valley species may have a greater ability to compete for light, whereas ridge species have a greater ability to compete for soil N. The broad distribution of uniform species probably reflects an ability to effectively compete for both light and soil N.  相似文献   

20.
刘蕾  申国珍  陈芳清  罗璐  谢宗强  喻杰 《生态学报》2012,32(7):2142-2149
研究神农架地区典型森林凋落物现存量及其养分动态对认识我国北亚热带森林生态系统养分循环过程及森林碳循环的机理具有重要的参考价值。通过对神农架海拔梯度上4种典型森林常绿阔叶林、常绿落叶阔叶混交林、落叶阔叶林及亚高山针叶林凋落物年凋落量及其养分归还量的研究,发现:森林凋落物量随海拔增加呈现先上升后降低的趋势,由低海拔到高海拔,凋落物年凋落量分别为6807.97、7118.14、6975.2和4250.67 kg/hm2。各森林类型凋落物量年变化呈双峰型,高峰期出现在4-5月份、11月份。凋落物养分归还以N 最高(132.06、162.29、157.12和185.77 kg/hm2),以P最少(4.62、4.39、8.24和4.15 kg/hm2),养分归还总量随海拔高度增加而减少。  相似文献   

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