首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Quantitative assessment of tree species diversity from sample plots in seven forest ranges of Nayagarh Forest Division in Odisha state in the Eastern Ghats of India was made during the period April, 2011 to November, 2013. A total of 120 transects(1000 m × 5 m) were laid in Nayagarh, Odogaon, Pancharida, Khandapada, Dasapalla,Mahipur, and Gania forest ranges and tree stems of at least 30 cm GBH were measured. The regeneration potential of trees was assessed from 5 m × 5 m sample plots located within the main transect. A total of 177 tree species belonging to 120 genera and 44 families were recorded from the study area. Shorea robusta, Buchanania lanzan, Lannea coromandelica, Terminalia alata and Cleistanthus collinus were the predominant tree species. The stand density varied in the range of 355.33–740.53 stems h~a)-1) while basal area ranged from 7.77 to 31.62 m~2 ha~(-1). The tree density and species richness decreased with increasing girth class. The highest number of species and maximum density was recorded in the girth class of 30–60 cm. The Shannon–Weiner and Simpson Indices with respect to trees with C30 cm GBH varied in the range of 2.07–3.79 cm and 0.03–0.37 cm respectively and the values of diversity indices are within the reported range for tropical forests of Indian sub-continent. The families, Dipterocarpaceae,Anacardiaceae, Combretaceae and Euphorbiaceae contributed to maximum species richness, stand density, and basal area. Regeneration of many tree species was observed to be poor. The present study provides baseline data for further ecological studies, forest management, and formulation of site-specific strategies for conservation of biological diversity in moist deciduous forests of Eastern India.  相似文献   

2.
Wild pistachio tree (Pistacia mutica) is considered the most important species in the Zagros forests. It can adapt to unfavorable environmental conditions. To find the suitable ecological conditions for pistachio species, we investigated different environmental factors such as gradient, aspect and position of the slopes through the distribution area. Frequency of pistachio trees in the north and northwest of Qalajeh forests was 36.4% and 1%, respectively. Maximum (32%) and minimum (13%) number of wild pistachio trees were in 30%–60% and >120% slope classes, respectively. The most number and least number of pistachio trees were found at elevations of 1100–1200 m and 2200–2300 m, respectively. The percentage of pistachio canopy coverage was 10. The average percentage of herbaceous coverage was 6.5. Pistachio trees of diameter per hectare at breast height (DBH) >20 cm numbered 5 while average number of pistachio trees was 8 per hectare. Pistachio seedlings per hectare averaged 3.5. The number of other species per ha was 7 trees. The effect of aspect on other species was not significant (p=0.151). Slope class and geographical aspect did not affect regeneration (p=0.275 and p=0.111, respectively). Pistachio plays an important economic role in semi-arid areas, therefore it is essential to protect and restore Qalajeh forests through participation by government and local people.  相似文献   

3.
We investigated the floristic composition, phytosociological and regeneration status of Sarkot Van Panchyat (community forest) in Chamoli district of Garhwal Himalaya. A total of 52 plant species of 46 genera and 26 families were recorded, which included 12 trees, 18 shrubs and 22 herb species. Quercus leucotrichophora was dominant tree species in sapling and seedling layers, followed by Lyonia ovalifolia and Rhododendron arboreum.Out of 12 tree species, 7 species in seedling stage and 8 species in sapling stage were recorded in the study area. The 44.41% species in the study area showed good regeneration status, 16.66% species were fairly regenerating,and 8.33% species showed poor regeneration status, while 33% species were not regenerating. Number of individuals from lower girth classes (0 10 cmand 10 30 cm) showed decreasing trend with the increase in size of girth class. Shannon index (H) for trees, shrubs and herbs was recorded as 1.82,2.24 and 2.41 respectively. Simpsons index (CD) was recorded as 0.21, 0.12and 0.12 for trees, shrubs and herbs respectively. The forest should be divided into compartments for better management purpose and each compartment should be closed for five years to assist regeneration and enrichment planting may also be carried out for sustainable management.  相似文献   

4.
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.  相似文献   

5.
Sprout contribution to natural regeneration of Rhododendron arboreum following the tree felling for fuel wood and other purposes was studied in two disturbed sites (Paipraw and Falockchar) of Rhododendron forest in Arunachal Pradesh, northeast India. Cut stumps were categorized into seven girth and height classes to evaluate the effect of stump girth and height on production of sprouts. Effect of stump girth on survival of sprouts was also investigated. Results show that highest number of cut stumps is recorded in medium girth classes (50–80, 80–110, and 110–140 cm) in both Paipraw and Falockchar stands. However, density of cut stumps is higher in Paipraw (1 210 stumps·ha−1) than Falockchar (1 154 stumps·ha−1). Nevertheless, a little higher percentage of sprouting is recorded in Falockchar (18%) than that of Paipraw (15%). Similarly, maximum number of cut stumps is observed in the medium height classes (50–80, 80–110 and 110–140 cm) in both the sites. Cut stumps with lower girths show greater ability of sprouting than that of larger girth classes. Significant correlations are observed between stump girth and sprout number and between stump height and number of sprouts. Survival of sprouts also depends on stump girth. Survival of sprout shows significant variations between different sampling times in both the sites. Though overall sprout regeneration of R. arboreum is very poor, sprouts arising from lower girth classes survive well than those of higher girth classes. The findings of this investigation signify that stump sprouting is not playing much role in the natural regeneration of R. arboreum though it has the ability to sprout. Sprout survival is not adequate to restore a stand where indiscriminate tree felling is continued and the species may be considered as a poor coppicer. Therefore, regeneration through seeds and seedlings should be preferred over regeneration through sprouting.  相似文献   

6.
Tree species diversity and population structure at different community types were described and analyzed for primary and secondary lowland moist deciduous forests in Tripura.Overall 10,957 individual trees belonging to 46 family,103 genera and 144 species were counted at ≥30 cm DBH(diameter at breast height) using 28 permanent belt transects with a size of 1 ha(10 m × 1000 m).Four different tree communities were identified.The primary forests was dominated by Shorea robusta(mean density 464.77 trees ha-1,105 species) and Schima wallichii(336.25 trees ha-1,82 species),while the secondary forests was dominated by Tectona grandis(333.88 trees ha-1,105 species) and Hevea brasiliensis(299.67 trees ha-1,82 species).Overall mean basal area in this study was 18.01m 2 ·ha-1 ;the maximum value was recorded in primary Shorea forest(26.21 m 2 ·ha-1).Mean density and diversity indices were differed significantly within four different communities.No significant differences were observed in number of species,genera,family and tree basal cover area.Significant relationships were found between the species richness and different tree population groups across the communities.Results revealed that species diversity and density were increased in those forests due to past disturbances which resulted in slow accumulation of native oligarchic small tree species.Seventeen species were recorded with <2 individuals of which Saraca asoka(Roxb.) de Wilde and Entada phaseoloides(L.) Merr.etc.extensively used in local ethno-medicinal formulations.The present S.robusta Gaertn dominated forest was recorded richer(105 species) than other reported studies.Moraceae was found more speciose family instead of Papilionaceae and Euphorbiaceae than other Indian moist deciduous forests.Seasonal phenological gap in such moist deciduous forests influenced the population of Trachypithecus pileatus and capped langur.The analysis of FIV suggested a slow trend of shifting the population of Lamiaceae group by Moraceae species in secondary T.grandis L.dominated community.  相似文献   

7.
分别在哀牢山湿性常绿阔叶林沟谷和坡面调查了10个20m×50m的样地,研究哀牢山湿性常绿阔叶林木质藤本植物的物种多样性及其与支柱木的关系。结果表明:研究区共记录到DBH≥1cm的木质藤本植物402株(隶属于23种21属16科)和DBH≥10cm的林木1522株(隶属于47种30属15科);与其他亚热带森林比较,该森林中木质藤本植物物种较为丰富但多度较低;藤本植物的物种丰富度、密度和基面积在沟谷显著高于坡面,而林木的差异性不显著;木质藤本植物在支柱木上呈集群分布,并且不同种支柱木被藤本植物攀援的百分比间存在显著的差异(P0.001),说明藤本植物的攀援对支柱木具有选择性;云南越桔、薄叶马银花和景东冬青等树种因其树皮光滑而不易被藤本植物攀援,而腾冲栲、七裂槭、山矾和多花山矾等则易于被藤本植物攀援;大径级支柱木被藤本植物攀援的比率高于小径级支柱木;茎缠绕和钩刺攀援藤本的胸径与支柱木胸径极显著相关(P0.001),根攀援和卷须攀援藤本的胸径与支柱木胸径相关性不显著(P0.05)。  相似文献   

8.
Forest structure and floristic composition were studied in a series of 0.5 ha natural forest plots at four sites near Porto Trombetas in Pará State, Brazil, 11–12 years after being subjected to differing levels of above-ground biomass harvest and removal. In addition to undisturbed control plots, experimental treatments included: removal of most trees ≥45 cm DBH (low intensity harvest); removal of trees <20 and ≥60 cm DBH (moderate intensity harvest); clear-cutting (100% above-ground biomass removal). Post-harvest basal area growth generally increased with harvest intensity, and total basal areas for trees ≥5 cm DBH were, at the time of our study, 60% (in the clear-cut) to about 80% of those in the control plots. Biomass harvests stimulated recruitment and growth of residual trees, particularly in the smaller diameter classes, but had little effect on species richness for small trees, seedlings, vine, herbs, and grasses. Species richness for trees ≥15 cm DBH was greater in the control and low-intensity (74–75 species) than in the moderate intensity (47 species) and clear-cut (26 species) treatment plots. While the tree flora within all harvest treatments was broadly similar to the undisturbed (control) plots and included similar numbers of species of the major plant families typical of the surrounding forests, the more intensive harvest treatments, especially the clear-cut, were dominated by a higher proportion of short-lived, early successional tree species.  相似文献   

9.
Large cavity-nesting birds depend on large-diameter trees for suitable nest sites. The increased spatial extent of commercial timber harvesting is modifying forest structure across the land base and may thus compromise the availability of large trees at the landscape scale. In this study, our objectives were to (1) characterize the availability of large living and dead trees in old-growth stands dominated by different tree species and surficial deposits that encompass the range of natural cover types of eastern Québec's boreal forest; (2) analyze the distribution of trees among decay-classes; and (3) compare the availability of large trees in unharvested, remnant, and harvested stands for the entire range of decay-classes. A total of 116 line transects were distributed across unharvested forests, remnant linear forests, and cutblocks in cutover areas. Unharvested forest stands (black spruce [Picea mariana], balsam fir [Abies balsamea]–black spruce, balsam fir–white spruce [Picea glauca] and balsam fir) reflected a gradient of balsam fir dominance. The remnant forests selected were isolated for 5–15 years. Analyses were performed at two diameter cut-off values. Trees with DBH ≥20 cm were considered for availability of total trees whereas trees with DBH ≥30 cm were considered for availability of large trees. Forest stands comprised high proportions of standing dead trees (33% of all stems, 8% were large dead stems). Availability of total and large standing trees increased with the dominance of balsam fir in stands. Forest stands located on thick surficial deposits showed higher densities of large dead trees for every stand type suggesting a higher productivity on those sites. Availability of stems according to decay-classes showed a dome-shaped distribution with higher densities of snags in intermediate decay stages. However, for large stems, black spruce stands showed a significantly lower availability that was consistent across all decay-classes. In linear remnant forests, pure balsam fir stands were absent. Remnant stands thus showed a much lower availability in large trees when compared with unharvested balsam fir stands. Clearcuts had the lowest densities of dead trees across sampled stands. Current even-aged management practices clearly affect availability and recruitment of large trees, therefore forest-dwelling wildlife relying on these structures for breeding is likely to be affected by large-scale harvesting in coniferous boreal forests.  相似文献   

10.
We examined the floristic significance of soil seed banks in relation to valley, midslope and ridge sites in a 70–90-year old forest in northeastern Connecticut. A-horizon mineral soils were collected to 5 cm depth in the early spring from forest understory sites across the topography. Samples from each of the sites were exposed to full sun within a greenhouse. Records of germination were made at regular intervals over a 60-day period. These showed significant differences among sites in number of species and total number of germinants. Greatest numbers of species and germinants were recorded from valley sites and these progressively declined from midslope to ridgetop. Twenty-five different species were identified. Species were grouped into growth habits – graminoids, herbs, shrubs, trees, and vines. Over 61% of all germinants across all sites were graminoids. Seventy-four percent of all germinants in the valley sites were graminoids, with over 93% of them represented by two sedge species, Carex glaucodea and C. lupulina. On the ridgetop sites graminoids were more evenly distributed among six different species. The percentage in each growth habit changed rank across topographic position with germinants of graminoids and trees most abundant on valley sites; herbs, on midslopes, and shrubs, on ridgetops. All germinants, except for those of the trees, Carex spp., and two herb species were weedy species that were not characteristic of the existing vegetation. Germinants of the trees, Carex spp., and herbs that were characteristic of the existing vegetation were mostly confined to soils from the valley sites. Two weedy herbs, Plantago major and Verbascum thapsus, are exotic introductions that originally came from Europe. Only one vine, Vitis aestivalis, from a midslope site germinated. Species diversity is higher on midslope sites than valleys and ridgetops. The significance of these findings in relation to site productivity and disturbance history is discussed.  相似文献   

11.
以通山县大幕山林场国家储备林为研究对象,按蓄积采伐强度设置对照(0%)、低强度(15.7%)、中强度(27.0%)、高强度(36.0%)、超高强度(45.6%)5个处理建立20块固定样地,对杉檫混交林目标树经营成效进行了监测。结果表明:作业样地2020年与2019年相比,目标树平均胸径生长量增加0.52 cm/年,单位面积蓄积生长量增加4.38 m3/(hm2·年);同时,2020年4种采伐强度作业样地平均每100 m2天然更新树种数6.25个,新增天然更新株数21株,而对照样地每100 m2天然更新树种数仅3个,新增天然更新株数仅12株。由此可见,目标树经营既促进了林木胸径生长,增加了林分蓄积量,同时又改善了林下天然更新,增加了物种多样性,可为国家储备林项目营林措施的选择提供有力支撑。  相似文献   

12.
Sustained management of natural forest depends on their ability to regenerate. The pace at which older trees are replaced by younger ones is important in this respect. This study was conducted to assess the demographic details of natural regeneration dynamics of south Indian moist deciduous forests. The status of natural regeneration has been assessed in eight localities of varying levels of disturbance in Thrissur Forest Division of Kerala State of southwest India. Enumeration of trees and their regeneration were analyzed at three levels of organization; whole-stand, stratum, and species.The trees of the forest were grouped into upper, middle and lower vertical strata. Species richness was highest in the middle stratum. Upper stratum species were commercially important. The mean basal area for the Forest Division was 12.83 m2/ha. and average number of trees per hectare (>=20 cm dbh) was 150. Regeneration of the upper stratum species was higher at about 10% gap in the canopy.The growing stock of established seedlings and saplings (height > 100 cm and dbh <=10cm) was very low compared to unestablished seedlings (height <=100 cm). Owing to very low survival probability in the sapling stage (dbh >=1 cm to <=10 cm), a low numbers of poles (dbh >=10 cm to <=20 cm) in the upper stratum was observed. Presence of fire, grazing, browsing and over expoitation by humans are the major constraints of natural regeneration recognized in these forests.  相似文献   

13.
Increased mortality rates in Scots pine (Pinus sylvestris) forests have recently been observed in the inner alpine Swiss Rhone valley. Drought, in combination with stand competition, mistletoe infections as well as nematode and insect infestations, appears to be the main factor for the decline. In focus of this study was the occurrence and role of fungal pathogens in the decline dynamics. Branches, stems and roots of 208 trees in five different crown transparency classes were collected and inspected for blue stain and fungal infections. Neither Armillaria species nor Heterobasidon annosum s. str. were detected, but blue stain was commonly observed. Visible blue stain increased with increasing crown transparency. Among the recently dead trees, 80% showed visible blue stain in the branches, 90% in the roots and 100% in the stems. In the crown transparency classes 2 and 3 (25–60% crown transparency), five of the 103 trees showed visible blue stain in the roots, one of 130 trees in the stem but none in the branches. Blue‐stain fungi were isolated from all parts of the trees and from all crown transparency classes. Overall incidence of blue stain was highest in the roots and lowest in the branches. In class 2, roots of 60% of the trees were visibly blue‐stained or developed blue stain in culture, but stems of only 24% and branches of 14% of the trees. In the roots Leptographium species, mostly L. serpens, dominated. From stems and branches, mainly Ophiostoma species were isolated. The positive relationship between the incidence of blue stain and crown transparency, in combination with the high infection levels of roots of fairly vigorous Scots pines, indicates the pathogenic potential of the blue‐stain fungi. Hence, these fungi together with their insect vectors may well act as an important contributing factor involved in pine decline.  相似文献   

14.
15.
Abstract

In forestry operations riparian buffer zones have been retained mainly to protect water quality. Because riparian forests are also important for maintaining terrestrial biodiversity, the associated ecotones need to be characterized and defined. Forest characteristics were studied along 50 m lakeshore–upland gradients in semi-natural forests in boreonemoral Sweden. Significant changes in the density of living and dead trees, as well as in their diameters, were recorded. The edge influence was generally discernible 10–30 m from the shoreline and was manifested in the very high density of understorey and midcanopy trees. The species-specific responses reflected the known shade and flooding tolerances of tree species. Most dead trees were standing, or broken from the roots or tree base; relatively few uprooted trees were recorded, suggesting that wind is only a moderate mortality factor. In comparison with the literature, the studied lakeshore forests are distinct from managed and set-aside upland forests in terms of tree species composition and woody debris characteristics; they thus contribute to landscape heterogeneity. If buffer zones along lakes were designed so that they captured the entire riparian ecotone, this would increase their contribution to the conservation of terrestrial biodiversity.  相似文献   

16.
The African tulip tree, Spathodea campanulata Beauv., is an introduced species forming novel forest types in Puerto Rico. These forests develop naturally after deforestation, agricultural use and land abandonment, and there are many questions as to their ecological characteristics. We sampled structure and species composition of large, small, and juvenile trees (≥10, ≥2.5 to <10, and <2.5 cm diameter at breast height, respectively) in nine secondary forests dominated by S. campanulata on alluvial, karst, and volcanic substrates in northcentral Puerto Rico. No differences were found in S. campanulata forest structure between substrates. Of a total of 79 species found, 17 were introduced. Forests on karst and alluvium had the highest and lowest global species richness, respectively. Species richness increased from large to small to juvenile trees in most sites, but more so on karst. The percentage of introduced species was inversely related to species richness of tree size classes on all substrate types. The dominance of S. campanulata in the large tree size class was highest and lowest in alluvial and volcanic sites, respectively, and decreased from large to small to juvenile trees on all substrate types. Species richness of S. campanulata forests is lower than that of native forests on equivalent substrates. Although land use history affects composition, the juvenile tree species established in S. campanulata forests seems to correspond to the geological substrate were sites are found. This study shows S. campanulata restores forest structure and native tree species on abandoned agriculture and grazing lands in Puerto Rico. Management of these novel forests should consider them as resources were natural processes have the potential of making them more diverse.  相似文献   

17.
We examined the variation in woody plant species composition, regeneration and biodiversity in relation to topographic heterogeneity, specifically catena shape (V and Λ) and slope position (summit, shoulder, back slope, foot slope and toe slope). All research took place at the TMU Experimental Forest Station, located in northern Iran. Two sets of replicated quadrats were established along transects that encompassed the different catena shapes and positions. We recorded the density, height, and canopy cover of all trees ≥12 cm diameter at breast height within 30 quadrats (400m2), as well as the density of all tree regenerations within 120 quadrats (4m2). In addition, three measurements of biodiversity were calculated for both mature trees and regenerations. Mature tree species composition varied greatly with catena shape and slope position, as did that of regenerating trees. Despite differences in species composition, the various measurements of biodiversity were consistent across the landscape for mature trees, whereas significant variation in evenness was detected for regenerating trees. We concluded that the broad matrix of environmental conditions occurring within this rugged mountainous area generates a variety of microhabitats, which in turn contributes to both the variation in species composition and the consistent biodiversity of these forests.  相似文献   

18.
Abstract

Trends in the incidence of multi-trunking at 21 sites in Glenbranter Forest in western Scotland are reported. Monitoring began in 1978 and continued for 30 years except at five sites that were felled. Incidence varied greatly between sites, from 9% up to 67% of trees multi-trunked at age 15–16 years, but rates declined slowly at nearly all sites after this peak. Decline was partly due to trunk singling and partly to multi-trunked tree death; in generalised linear mixed model analyses, we found that singling showed a highly significant relationship to the girths of the main and second-ranked trunks, respectively positive and negative, and mortality showed a highly significant relationship to the difference between the main-trunk girth and plot mean girth. From observations at older sites monitored to felling, we predicted the final incidences of multi-trunking at three sites monitored since planting; for these sites, the trees predicted to remain multi-trunked had suffered substantially more leader browsing from deer when young than trees predicted to be finally single trunked. Sites planted in the 1970s are forecast to have final incidences of multi-trunking from 3 to 40%, with most expected to be in the range 20–30% multi-trunking. Hence appreciable losses in crop value are likely, and measures to combat multi-trunking are discussed.  相似文献   

19.
We studied temporal changes in the genetic structure and diversity of a naturally regenerated Picea abies (L.) Karst. (Norway spruce) population in the Bia?owie?a Primeval Forest, Poland. The analysis included five age classes of trees: newly germinating seedlings (in laboratory conditions), seedlings up to 3 years old, young trees 4–10 years old, middle-aged trees 11–100 years old, and trees older than 100 years. We conducted genetic analyses of 26 allozyme loci using dormant buds from 405 individuals and 100 embryos. The results showed that the naturally regenerating Norway spruce population is genetically heterogeneous across the studied age classes. As determined by Chi squared tests, there were statistically significant differences in frequencies of alleles and genotypes as well as Wright’s index values (F) among the five age classes. The level of genetic differentiation (pairwise FST = 0.5–2.3 %) among the age class groups was equal to levels previously determined for various populations of this species. The Ewens-Watterson test for neutrality showed that one or two loci across different age classes of Norway spruce were affected by the selection process. The distinctiveness of embryo and seedling classes was confirmed by the number of detected alleles, the number of private alleles, the level of observed heterozygosity, and Wright’s index value. The results obtained in the present study indicate there are interesting dynamics of adaptation processes occurring in the natural age-diverse population of Norway spruce in the Bia?owie?a Primeval Forest.  相似文献   

20.
We analyze the structure and composition of old-growth wet evergreen forest of Nelliampathy hills, the chain of hills lying immediately south of Palghat Gap, in the southern Western Ghats of India. We sampled 30 plots of 0.1 ha each (50m×20m) at six locations enumerating all plants≥10cm girth at breast height. We pooled the data and computed various structural parameters. There were 152 species of 120 genera and 51 families of the study area. Of these, 118 (77%) were trees, 24 were climbers (16%) and 10 were shrubs (7%). Species richness varied from 58 99 per 0.5 ha sample and Shannon indices of diversity ranged from 4.4 to 5.2. Fifty-nine per cent (89 species) of the species were Indian Sub-continent elements and 34% (51 species) are endemic to the Western Ghats. Fifteen species are listed in various threat categories. Aglaia and Litsea were the most species-rich genera. Numbers of families ranged from 27 43 per 0.5 ha sample. Euphorbiaceae and Lauraceae were the most species-rich families. Stand density varied from 1714 to 2244 stems·ha -1 and basal area from 53.6 to 102.1 m 2 ·ha -1 . The vegetation was dominated by 3 6 species and six dominance patterns characterized the species composition within the hill complex. The old-growth evergreen forests of Nelliampathy exist as small fragments rich in biodiversity and can be used as benchmarks for comparison with disturbed forests.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号