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1.
Traditional cultural and religious beliefs and practices in the form of sacred groves play a crucial role in environmental conservation and biodiversity. The present study was conducted to explore plant resources, their biological spectrum, leaf size spectrum, sacred grove conservation status, locally known as Kankabati Sitabala Than (KST) in the district of West Midnapore, West Bengal in India. The study's floristic list revealed that the KST vegetation was diverse and composed of 277 species of 238 genera distributed over 77 families under 36 orders according to APG IV classification, of which 87 species were aliens. Poales (23.40%) and Poaceae (15.38%) were the dominant order and family in terms of species wealth. Biological spectrum shows the study area was classified as “thero-crypto-chamaephytic” type of phytoclimate. Leptophyll (26.60%) and ovate (18.91%) were found to be high in the leaf size spectrum and lamina. The vulnerable climber and tree species are Cayratia pedata and Pterocarpus indicus. The vegetation phenology, observed during different seasons revealed that most of the species were dominant in rainy seasons (99.68%), followed by winter (69.87%) and summer (29.81%). The study area being a sacred grove remains fairly undisturbed. For the long-term conservation of germplasm of the grove some recommendations have been suggested.  相似文献   

2.
This paper reports the analysis of floristic composition and phenology of protected, annually scraped and fired, and heavily grazed grasslands community of Western Himalaya.
  1. A total of 19, 20 and 23 species were recorded at protected (S1), annually scraped and fired (S2) and heavily grazed (S3) sites respectively.
  2. Domination of therophytic flora as indicated by biological spectrum study, was noted in all the three sites.
  3. Density of plants reached a maximum in the rainy season and amounted to be 4300.5, 3439.8 and 3298.0 tillers/m2 on S1, S2 and S3 respectively.
  4. Maximum total basal cover was also recorded in the rainy season and amounted to be 769.9, 3390.6 and 2295.7 cm2/m2 on S1, S2 and S3 respectively.
  5. Correlation between density and basal cover was positive on all three sites.
  相似文献   

3.
R. S. Rana  V. Parkash 《Plant and Soil》1987,99(2-3):447-451
Summary Floristic composition studied in a 40 hectares representative site of alkali soils in the Indo-gangetic plains of Northwestern India revealed a remarkably restricted spectrum of natural vegetation. Soil analysis of specific niches, occupied by aggregations of different species, was employed to identify alkali halophytes. Response functions of eight prominent species to increasing levels of soil alkalinity, studied in pot culture, showed that most of them were adapted to alkali soils. Based on the computed importance value indices and observed biomass production maxima, it has been inferred thatSporobolus marginatus, Sporobulus coromandelianus, Diplachne fusca andChloris barbata, qualify as plant indicators of high-alkali soil conditions.  相似文献   

4.
This paper studies the crop biodiversity and its changing patterns across an altitudinal gradient of three highland village agroecosystems: Hinsa (2700 m), Jahlma (3000 m) and Khoksar (3200 m). It also deals with energy (kilocalorie (physiological); kcal or Megajoules; MJ) and monetary (Indian rupee; Rs) efficiency of traditional crops versus recently introduced cash crops in the cold desert of the Lahaul valley. Newly introduced cash crops like hop, pea and potato have drastically reduced the crop biodiversity along the increasing altitudes. Of the total cropped area, 70% is occupied by these cash crops. Organic manure, mainly derived from forests and night soil, accounted for 90 and 77% of the total energy input in traditional and introduced cash crops in all the three selected villages, respectively. The energy output/input for traditional crops ranged in Hinsa from 0.6 (Kuth (Sausurea lappa, family Asteraceae) — a root crop of medicinal use) to 6.1 (amaranths); for the introduced cash crops it varied from 0.9 (potato) in Hinsa to 2.8 (pea) in Jahlma. In terms of energy, traditional crops are richer and more viable than the introduced cash crops. Monetary output/input of traditional crops was 0.8 (maize) to 11.8 (Kuth) and for introduced cash crops it was from 1.8 (potato) to 6.2 (hop). Overall, the average monetary efficiency of introduced crops was higher than that of traditional ones. Taking the average of the three villages, the energy and monetary output/input for the introduced cash crops was 1.4 and 3.3, respectively. However, for the purpose of food security and environmental conservation there is a need to establish a balance between traditional and introduced cash crops. This will make farming sustainable in the cold desert environment where crop growth period is limited. The Lahaul valley is landlocked and due to heavy snow deposits at Rohtang pass (3978 m), its main entry from Kullu valley remains accessible only for 5 months (July–November).  相似文献   

5.
Most of southern Brazil is located in a subtropical region, thus representing a climatic and biogeographic transition, which results in different floristic contingents of both tropical and temperate origin in any particular study area. In order to verify the biogeographic affinities of climbing plants, a floristic survey was carried out in a Semideciduous Seasonal Forest remnant located in mideastern Rio Grande do Sul. The presence of the sampled species was recorded for three gradually more distant areas along four divergent expansion lines starting from the study area: northeast, northwest, midwest, and southwest. The distribution data were compiled from the available local and regional literature. The 82 species found comprised 55 genera and 33 families; most species occurred in a single family (Asteraceae), followed secondarily by Apocynaceae, Passifloraceae, Bignoniaceae and Fabaceae. Many species presented a relatively large geographic range, and most species occurred along the northern tropical expansion line. Multivariate analysis included the study area in a group formed exclusively by rain forests of a northeastern expansion line, indicating a southern continuity of the Brazilian Atlantic Forest, although it was locally represented by a lower number of species.  相似文献   

6.
Abstract. This study deals with the floristic composition of lowland tropical forest in the watershed of the Panama Canal. The floristic composition of large trees in 54 forest plots was analysed with respect to environmental factors, including precipitation, geologic parent material, stand age, topography, and soils. The plots contain 824 species of trees with a diameter at breast height ≥10 cm and represent a regional flora with exceptional β‐diversity. Plot data indicate that the Panamanian forest is strongly spatially structured at the landscape scale with floristic similarity decreasing rapidly as a function of inter‐plot geographic distance, especially for distances <5 km. The ordinations and patterns of endemism across the study area indicate broad floristic associations well correlated with Holdridge life zones. The results indicate the positive aspects of life zone classification at regional scales, while simultaneously highlighting its inadequacy for finer scales of analysis and resource management. Multivariate gradient analysis techniques (Non‐metric Multidimensional Distance Scaling and Detrended Correspondence Analysis) show clear patterns of floristic variability correlated with regional precipitation trends, surficial geology, and local soil attributes. Geologic and edaphic conditions, such as acidic soils or excessively drained limestone substrates, appear to override the effects of precipitation and modify forest composition. We conclude that the Panamanian forest shows clear patterns of spatial organization along environmental gradients, predominantly precipitation. The rapid decline in floristic similarity with distance between stands also suggests a role for dispersal limitation and stochastic events.  相似文献   

7.
In 1949 an area of undisturbed warm temperate rainforest (simple notophyll vine forest) in mid-north coastal New South Wales, Australia was studied in terms of both floristics and structure (Burges A. & Johnston R. D. J. Ecol. 41, 72-83, 1953). During 1955-56, the area in which the transect was located was logged. Over 90% of the upper closed canopy trees adjacent to the creek and on the lower slope and about 35% of canopy trees on the upper slope were removed. The area was reassessed in terms of floristics and structure in 1981. The greatest impact of logging in the study area was structural and largely confined to the flat adjacent to the creek and to the lower slope. With the exception of the remaining gaps covering 6% of the area, structural recovery time is estimated at 140-190 yr. In the gaps structural recovery may take up to 250 yr. All flowering plants, ferns and mosses previously recorded were present 25 yr after logging. The two alien plant species on the site are short lived intolerant species and gradually disappearing with canopy closure of the regenerating forest. The regeneration of the original tree species is healthy and vigorous with most regeneration resulting from the growth of advance regeneration present at the time of logging or the germination of new seedlings. Eleven per cent of the regeneration is attributable to coppicing. The importance of remnant canopy trees as a source of propagules for the trees and epiphytes is recognised. The larger openings are slower to recover as a result of lack of protection from frost. The stability of floristic composition of this area of warm temperate rainforest following heavy logging is demonstrated.  相似文献   

8.
van Andel  T.R. 《Plant Ecology》2003,167(2):293-317
This paper reviews the floristic composition, vegetation structure, and diversity of three types of swamp forest that cover a considerable part of Guyana's North-West District. Trees, shrubs, lianas, herbs, and hemi-epiphytes were inventoried in three hectare plots: one in Mora forest, one in quackal swamp, and one in manicole swamp. The Mora forest, flooded annually by white water, was dominated by relatively few, large individuals of Mora excelsa. The very dense, thin-stemmed quackal forest, almost permanently flooded by black water, was characterized by Tabebuia insignis and Symphonia globulifera and contained few palms. The somewhat less dense manicole swamp, flooded regularly by brackish water, was distinguished by large numbers of Euterpe oleracea. Although the three swamps showed little overlap in floristic composition and densities of dominant species, they represent some of the lowest diversity forest in the Neotropics, with an -diversity of 7.4 for the Mora forest, 8.2 for the quackal forest and 5.7 for the manicole swamp. When compared with similar vegetation types in the Guiana Shield, the swamp forests in this study show some interesting differences in species composition and density. The wetlands of the North-West District form the last stretch of natural coastline in Guyana and play an important role in the protection of riverine ecosystems. Furthermore, there is commercial potential for the extraction of non-timber forest products from these low-diversity forests. Nevertheless, in prolonged dry periods, large tracts of quackal forest are being burnt to give way to almost treeless, flooded savannas. For these reasons, adequate management and conservation strategies must be developed for the area.  相似文献   

9.
大别山山核桃林植物组成与区系特征研究张旭东,黄成林(安徽农业大学,合肥230036)叶志琪(合肥林业学校,合肥230031)FloristiccompositionanditscharacteristicsofCaryacathayensisfore...  相似文献   

10.
Communities containing bolster (hard cushion) plants are widespread in alpine and subalpine treeless plant communities in Tasmania. Numerical analysis of species presence/absence data from 227 quadrats defined thirteen communities, the distributions of which proved strongly related to a southwest to northeast edaphic gradient and altitude. The high altitude communities and those on oligotrophic soils are most likely to be dominated by bolster species, whereas the eastern communities are more frequently dominated by shrubs or graminoids.Nomenclature follows Curtis (1963, 1967), Curtis & Morris (1975), Curtis & Stones (1978) and Willis (1970) except where authorities are given at first mention. Structural nomenclature follows Kirkpatrick (1983).  相似文献   

11.
Traditional attempts to delineate floristic regions are typically based on the qualitative analysis of species distribution, often ignoring the phylogenetic relationships among their taxa. Ethiopia and Eritrea are in the Horn of Africa, known as one of the world's biodiversity hotspots. We quantitatively classified the flora of Ethiopia and Eritrea into meaningful geographical units by analyzing the taxonomic and phylogenetic β‐diversity at genera, total species, and endemic species levels at a scale of 0.5° × 0.5° grid cells. Hierarchical clustering was used to quantitatively delimitate the flora and analysis of similarities was used to test the significant difference between the derived groups in taxonomic composition and phylogenetic relatedness. In total, two floristic subprovinces, five floristic districts, and 13 floristic subdistricts, as well as three centers of species endemism associated with three floristic subdistricts were identified. Our results also showed that the species diversity, endemism, and turnover of the highlands in Ethiopia and Eritrea were much higher than the lowlands, indicating that the floristic differences are closely related to the topography of the East African Rift. In this study, we provided a scientific framework for the composition and relationships of the floristic units in the Horn of Africa, and similarly provided a scientific basis for better conservation of the diversity in this region.  相似文献   

12.
The floristic composition and structure of a premontane moist forest remnant were studied in the El Rodeo Protected Zone, Central Valley of Costa Rica. Three one-hectare plots were established in the non-disturbed forest, and all trees with a diameter at breast height (dbh) of 10 cm or greater were marked, measured and identified. The plots were located within a radius of 500 m from each other. A total of 106 tree species were recorded in the three plots. Average values: species richness 69.6 species ha-1, abundance 509 individuals ha-1, basal area 36.35 m2 ha-1. Total diversity was 3.54 (Shannon Index, H'), and the species similarity among the plots ranged between S = 0.68 and 0.70 (S?rensen Similarity Index). Most tree species are represented by few individuals (five or less). There is a lack of emergent trees and arborescent palms in the forest canopy. According to the Familial Importance Value, Moraceae, followed by Fabaceae, Lauraceae, and Sapotaceae, largely dominates this forest. Pseudolmedia oxyphillaria (Moraceae) is the dominant species (Importance Value Index), accounting for 25% of all the marked trees in the plots, followed by Clarisia racemosa (Moraceae), Heisteria concinna (Olacaceae), and Brosimum alicastrum (Moraceae). The size class distributions were similar among plots, and in general followed the expected J-inverted shape. Differences in tree abundance, floristic composition, and spatial distribution of some species among the plots suggest heterogeneity of this ecosystem's arborescent vegetation. Moreover, it is an important natural reservoir for the conservation of rare and endangered tree species in a national level. Using these results as a baseline, this study should start a long term monitoring of the structure and composition of this very reduced and fragmented ecosystem.  相似文献   

13.
《农业工程》2020,40(3):197-203
This study was conducted to assess the floristic composition, biological spectra and phenology of Tehsil Balakot. Frequent visits were made in different seasons during 2012–13. Field notebook was used to record the data within field. Biological spectrum and leaf sizes classes were determined. The floristic diversity revealed 228 plant species belonged to 184 genera and 72 families. Asteraceae family contributed maximum number of species (27) followed by Rosaceae (18), Apiaceae and Lamiaceae (12) species each, Papilionaceae (11) species while remaining 67 families contributed less than 10 species. Herbaceous growth form was the most leading one (71%), followed by shrub (15%) and tree (14%), respectively. Biological spectrum revealed that hemicryptophytes (32.45%) were the most prevalent, followed by therophytes (31.57%), nanophanerophytes (15.35%), megaphanerophytes (13.59%) and chamaephytes (4.38%). Leaf spectra showed that microphyll (28.94%) were dominant, followed by nanophyll (27.19%), leptophyll (22.80%), mesophyll (14.03%) and megaphyll (7.01%). The flora was influenced by two flowering seasons i.e. March to August and September to February. In the first spell, 193 species were recorded, of these 15.54% trees, 15.02% shrubs, 63.21% herbs, 3.62% grasses and 2.59% ferns; while in the second spell, there were 35 species having 2.85% trees, 17.14% shrubs, 74.28% herbs, and 5.71% grasses. The flowering data shows that June and July were the utmost flowering months with 28.50% in 65 and 20.17% in 46 plant species.  相似文献   

14.
The Amazon region is one of the most diverse areas in the world. Research on high tropical forest diversity brings up relevant contributions to understand the mechanisms that result and support such diversity. In the present study we describe the species composition and diversity of 15 one-ha plots in the Amazonian terra firme dense forest in Brazil, and compare the floristic similarity of these plots with other nine one-ha plots. The 15 plots studied were randomly selected from permanent plots at the Embrapa Experimental site, Amazonas State in 2005. The diversity was analysed by using species richness and Shannon's index, and by applying the Sorensen's index for similarity and unweighted pair-group average (UPGMA) as clustering method. Mantel test was performed to study whether the differences in species composition between sites could be explained by the geographic distance between them. Overall, we identified 8 771 individuals, 264 species and 51 plant families. Most of the species were concentrated in few families and few had large number of individuals. Families presenting the highest species richness were Fabaceae (Faboideae: 22spp., Mimosoideae: 22spp.), Sapotaceae: 22spp., Lecythidaceae: 15 and Lauraceae: 13. Burseraceae had the largest number of individuals with 11.8% of the total. The ten most abundant species were: Protium hebetatum (1 037 individuals), Eschweilera coriacea (471), Licania oblongifolia (310), Pouteria minima (293), Ocotea cernua (258), Scleronema micranthum (197), Eschweilera collina (176), Licania apelata (172), Naucleopsis caloneura (170) and Psidium araca (152), which represented 36.5% of all individuals. Approximately 49% of species had up to ten individuals and 13% appeared only once in all sampled plots, showing a large occurrence of rare species. Our study area is on a forest presenting a high tree species diversity with Shannon's diversity index of 4.49. The dendrogram showed two groups of plots with low similarity between them (less than 0.25), and the closer the plots were one to another, more similar in species composition (Mantel R = 0.3627, p < 0.01). The 15 plots in our study area share more than 50% of their species composition and represent the group of plots that have the shortest distance between each other. Overall, our results highlight the high local and regional heterogeneity of environments in terra firme forests, and the high occurrence of rare species, which should be considered in management and conservation programs in the Amazon rainforest, in order to maintain its structure on the long run.  相似文献   

15.
李保贵 《广西植物》2015,35(1):42-52
采用生态学样方调查及统计学方法,研究了云南勐腊望天树热带季节性雨林蕨类植物的组成及生态特征。结果表明:在1hm2(4个50m×50m,含400个5m×5m小样方)面积的样地里,记录有蕨类植物48种13 159株(丛);在生态特征上,40个地生蕨类的盖度之和占调查样地面积的22.45%,缺乏高盖度级种类;黑鳞轴脉蕨、长叶实蕨、多形叉蕨等属高频度级种类;长叶实蕨、多形叉蕨、黑鳞轴脉蕨、毛柄短肠蕨、薄叶牙蕨、思茅叉蕨等种的重要值之和占86.31%,它们是望天树林蕨类植物的典型代表种。生活型组成上,以地面芽植物占优势(达80%)。叶质主要由纸质叶(占54.17%)和草质叶(占27.08%)种类组成;叶形主要由羽状复叶种类组成(89.58%)。与西双版纳相同取样面积的山地常绿阔叶林比较,望天树林蕨类植物的种数及种群数量分别是山地常绿阔叶林的1.55倍及2.23倍。同一地区不同海拔和生境异质性是导致蕨类植物组成不同、种群数量变化的主要原因。该研究揭示了赤道热带北缘热带雨林蕨类植物的组成及生态特征,有利于与其它热带地区蕨类植物作进一步的比较研究。  相似文献   

16.
Abstract. Large isolated trees are a common feature of the agricultural landscape in humid tropical regions originally covered by rain forest. These isolated trees are primarily used as a source of shade for cattle and people. 13 pastures (totalling ca. 80 ha) currently used as cattle pasture were studied. In them, we registered 265 isolated trees belonging to 57 species. 50 trees of the most frequent species (Ficus spp. n = 30 and Nectandra ambigens n = 20) were selected to examine the influence of isolated trees on floristic composition and vegetation structure in the pastures. At each tree, three 4–m2 quadrats were sampled: under the canopy, directly under the canopy perimeter, and beyond the canopy in the open pasture. Under-canopy vegetation was structurally and floristically different from the other two sampling sites. Mean species richness per quadrat was significantly higher under the canopy (17.8 ± 4.3 SD) than at the canopy perimeter (11.2 ± 3.4) and in the open pasture (10.6 ± 3.6) sites. Stem density was higher at under-canopy sites, where greater proportions of endozoochorous and rain-forest species were found. Isolated trees function as nursery plants for rain-forest species by facilitating the establishment of zoochorous species whose seeds are deposited under the tree canopies by frugivorous birds or bats. Our results imply that isolated trees may play a major role in seed dispersal and establishment of native species, which is of consequence for the preservation of rain-forest species in these fragmented landscapes.  相似文献   

17.
The adequate protection and sustainable management of a tropical rain forest requires a good knowledge of its biodiversity. Although considerable parts of Guyana's North-West District have been allocated as logging concessions, little has been published on the forest types present in this region. The present paper reviews the floristic composition, vegetation structure, and diversity of well-drained mixed and secondary forests in northwest Guyana. Trees, shrubs, lianas, herbs and hemi-epiphytes were inventoried in four hectare plots: two in primary forests, one in a 20-year-old secondary forest and one in a 60-year-old secondary forest. The primary forests largely corresponded with the Eschweilera–Licania association described by Fanshawe, although there were substantial variations in the floristic composition and densities of dominant species. The late-succession forest contained the highest number species and was not yet dominated by Lecythidaceae and Chrysobalanaceae. There is a need for updating the existing vegetation maps of northwest Guyana, as they were based on limited information. Large-scale forest inventories may provide a fair indication of species dominance and forest composition, but do not give a reliable insight in floristic diversity. Although previous reports predicted a general low diversity for the North-West District, the forests plots of this research were among the most diverse studied in Guyana so far. These results will hopefully influence the planning of protected areas in Guyana.  相似文献   

18.
We conducted a phyto-ecological analysis of the Sebkha Djendli located in the semi-arid lands of the north-eastern Algeria in order to contribute in the understanding of flora composition, diversity and factors controlling plant zonation. Eight plots, distributed on the cardinal and intercardinal points of the site, were sampled. A floristic analysis (species richness, life forms, spatial occurrence, plant cover rate and similarity) and an assessment of the effect of soil salinity and pH on the cover of dominant halophytes were performed. The results of the floristic approach showed the presence of 51 species belonging to 21 families and 45 genera. The most frequent biological types were therophytes (58%) followed by chamaephytes (18%). Vegetation cover rate ranged from 50% to 95%. The distribution of vegetation all around the edges of the Sabkha revealed the dominance of halophytic species belonging to the family Chenopodiaceae. The variation of total halophytic vegetation cover over all sampled plots seems to be affected neither by the distance from waterbody nor by plot orientation nor by the electrical conductivity and pH of soil.  相似文献   

19.
Spectra on life form, leaf size, leaf persistence, flowering season, and shade tolerance of trees in different vegetation types occurring within the north-western catchment of the river Gola in Kumaun Himalaya are presented. The flora of Quercus leucotrichophora, Quercus lanuginosa and Quercus floribunda forests is phanerophytic, that of Pinus roxburghii and mixed forests therophytic. The grassland vegetation is characterized by the largest percentage of hemicryptophytes. The flora of the whole area, is therophytic. The biological spectrum for the entire Kumaun Himalaya is characterized as therohemigeophytic. Among the various altitudinal zones, the tropical has a preponderance of phanerophytes, the temperate and the alpine of hemicryptophytes.The observations on leaf size indicate that with the exception of Pinus roxburghii forest, in all vegetation types, the species with microphylls are greater in number. In this region, the vegetation expression is evergreen, although the tree flora has a considerable content of deciduous elements. In all the forests, the flowering period in most of the trees is vernal.On the basis of relative density, the greatest proportions of adult trees in the Pinus roxburghii and Quercus lanuginosa forests are shade intolerant, while in the mixed and Quercus leucotrichophora forests maximum trees are intermediate in shade tolerance. With the exception of the Pinus roxburghii forest, all the forests exhibit the dominance of trees which are shade tolerant at the seedling stage. On the basis of relative density, all forest types, except for Pinus roxburghii forest, have 74.5 to 100% trees with the potentiality of vegetative reproduction.Financial support from the Indian Space Research Organisation, Banglore and University Grants Commission, New Delhi is gratefully acknowledged.  相似文献   

20.
Field observations over a three-year period were used to document the floristic composition, flowering and fruiting sequences of the Sarcopoterium spinosa Mediterranean batha of Ariel. This plant community was found to be species-rich, with high percentages of annuals, bushes and geophytes, low percentages of herbaceous plants, climbers and trees, and ten species considered rare in Israel. Typical Mediterranean characteristics were observed in the S. spinosa batha: spring flowering reaching a peak in April, small between-year variation in flowering and fruiting, most species having Mediterranean distribution, and partial resistance to fire.  相似文献   

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