scholarly journals Species Diversity and Tree Regeneration Patterns in Tropical Forests of the Western Ghats, India

ISRN Ecology ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
R. Jayakumar ◽  
K. K. N. Nair

Study Aim. To assess species diversity and tree regeneration patterns of different vegetation types of Western Ghats, India. Rarefaction was used to estimate species diversity of different vegetation types. One-way ANOVA was used to test for differences in tree density and basal area of different vegetation types. Sorenson index of similarity was used to calculate change in species composition between mature trees and regenerating individuals. Results showed that species diversity and regeneration pattern of trees differ in different vegetation types of the forest landscape. Species-area and species-individual accumulation curve (rarefaction) against equal-sized sampling area in different vegetation types showed that species heterogeneity was higher in vegetation types at mid elevations while their abundance was higher in vegetation types at higher elevations. All the vegetation types of the study area were heterogeneously distributed. Tree regeneration was higher in species rich vegetation type with no sign of human disturbances. Change in species composition across mature and regenerating phase was more frequent in disturbed forest as compared to undisturbed or less disturbed forests. New entry species occur in all the vegetation types.

1999 ◽  
Vol 64 ◽  
Author(s):  
D. Van den Meersschaut ◽  
B. De Cuyper ◽  
K. Vandekerkhove ◽  
N. Lust

Natural  stand changes in the forest reserve of Liedekerke were analysed during the  period    1986-1996, using a permanent grid of circular plots. The monitoring  concentrated on natural    changes in species composition, using stem number and basal area as  indicators, and changes    in spatial distribution and colonization capacities of trees and shrubs,  with special interest in the    competition between exotic and indigenous species. After only a decade of  monitoring important    natural changes in the woody layer were detected. The pioneer forest is  gradually maturing    through self-thinning processes and shifts in species composition. The  overall stem number    decreased with 33.6%, while the basal area increased with 20.9%. Birch (Betula pendula/    pubescens) and indigenous oak (Quercus robur/petraea) remained  dominant. More tolerant    exotic species, like red oak (Quercus rubra) and sweet chestnut (Castanea  sativa), are slowly    increasing their share in the species composition and expanding their  range. Pioneer species on    the other hand, like aspen (Populus tremula), willow (Salix  capreaicinerealaurita), alder buckthorn    (Frangula alnus) and  common (Alnus glutinosa)  and grey alder (A. incana),  strongly declined.    Black cherry (Prunus serotina) seems to be slowly invading the forest due to its  massive    natural regeneration. Strong competition may be expected especially from  rowan ash (Sorbus    aucuparia), which showed similar regeneration  and colonization capacities. Elder (Sambucus    nigra) dramatically extented its range, though  its share remains marginal. Beech remained absent    most probably due to the lack of mature trees in the vacinity of the  forest. Finally this    change detection allowed that general predictions could be made on the  future natural development    and composition of this forest reserve, which could serve forest management  decisions.


2005 ◽  
Vol 32 (3) ◽  
pp. 248-259 ◽  
Author(s):  
RAMAN KUMAR ◽  
GHAZALA SHAHABUDDIN

Despite the fact that tropical dry forests are being exploited on a large scale for various forest products, there has been limited evaluation of the accompanying ecological impacts. In particular, there is no information on the effects of widespread biomass extraction such as grazing and firewood collection. A study was carried out in Sariska Tiger Reserve in northern India, to investigate the effects of biomass extraction on forest vegetation composition, diversity and structure. Biomass extraction caused significant changes in forest vegetation structure and species composition in the tree layer but the extent of these changes varied across the three major vegetation types found in the Reserve. Anogeissus-dominated slope forest showed significantly lower mean canopy cover, tree density, tree basal area and height of trees in disturbed sites in comparison to undisturbed sites. Riparian forest showed lower mean canopy cover, tree basal areas and number of recorded tree species in disturbed sites. Scrub forest had lower mean canopy cover, tree basal area and tree height. There were fewer tall trees but greater number of short trees in disturbed sites of all three vegetation types. Girths of trees similarly shifted towards lower values in riparian and scrub forest. In Anogeissus-dominated forest, disturbed and undisturbed sites did not differ in proportions of trees in various girth-classes. Tree species richness was substantially lower in disturbed sites of Anogeissus-dominated and riparian forest in comparison to undisturbed sites, but was not affected by disturbance in scrub forest. Understorey species richness was higher in disturbed sites of all three vegetation types but understorey changed structurally only in Anogeissus-dominated forest. Overall tree and understorey species composition was significantly different between disturbed and undisturbed sites of Anogeissus-dominated forest, but was unchanged in scrub and riparian forest. Observed changes in vegetation structure, diversity and composition of the different vegetation types due to biomass extraction have implications for biodiversity conservation in tropical dry forest ecosystems, and need to be addressed in future forest management planning.


Author(s):  
Nuru Mohammed

Aim: This study was conducted to assessing woody plant composition, population structure and regeneration status in lowland exclosure (EX) of Northern Ethiopia. Study Design: Investigation of parameters was undertaken from 71 plots with size of 20 m x 10 m laid systematically along transect lines for vegetation data. These 200 m2 plots were used for assessment of trees with DBH >5 cm. Small quadrats of 4 m*4 m (16 m2) nested within the bigger plots was laid at the four corners and center of each plots. These were used for measuring seedling and sapling individuals. To analyze species diversity, population structure and regeneration status of woody plants were by computing abundance, density, basal area, Importance value index (IVI) and using Shannon-Weiner diversity and evenness indices. Results: According to vegetation survey result, a total of 23, 17 and 26 woody species were recorded, at Kara, Erba and Shektekli exclosures (EXs), respectively. While 8, 7 and 5 species of woody plant were in open grazing land (OGL). The total mean densities of all woody plants were found to be 1530, 1480 and 2999 individual’s ha-1 at Kara, Erba and Shektekli in EXs. Conclusion: The study suggested that the regional government have to considering EXs as useful for restoration or rehabitation strategy in the region, the vegetation in all the EXs in the study sites have a higher species composition, diversity, density, increment of basal area and regeneration woody plants than OGL, as a result of management differences in EXs. However, there are also variation on species composition, diversity, density increment of basal area and regeneration woody plants among exclosures having similar age and altitude for instance the species recorded in Erba site is lower than with other of EXs, This could be due to among local site characteristic variation and high grazing happen before Ex establishment exists. Therefore, we need to apply soil and water conservation, enrichment planting with indigenous tree species and strengthen local management institution in effectively protect the exclosure.


Diversity ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 140 ◽  
Author(s):  
John L. Godlee ◽  
Francisco Maiato Gonçalves ◽  
José João Tchamba ◽  
Antonio Valter Chisingui ◽  
Jonathan Ilunga Muledi ◽  
...  

Seasonally dry woodlands are the dominant land cover across southern Africa. They are biodiverse, structurally complex, and important for ecosystem service provision. Species composition and structure vary across the region producing a diverse array of woodland types. The woodlands of the Huíla plateau in southwest Angola represent the extreme southwestern extent of the miombo ecoregion and are markedly drier than other woodlands within this ecoregion. They remain understudied, however, compared to woodlands further east in the miombo ecoregion. We aimed to elucidate further the tree diversity found within southwestern Angolan woodlands by conducting a plot-based study in Bicuar National Park, comparing tree species composition and woodland structure with similar plots in Tanzania, Mozambique, and the Democratic Republic of Congo. We found Bicuar National Park had comparatively low tree species diversity, but contained 27 tree species not found in other plots. Plots in Bicuar had low basal area, excepting plots dominated by Baikiaea plurijuga. In a comparison of plots in intact vegetation with areas previously disturbed by shifting-cultivation agriculture, we found species diversity was marginally higher in disturbed plots. Bicuar National Park remains an important woodland refuge in Angola, with an uncommon mosaic of woodland types within a small area. While we highlight wide variation in species composition and woodland structure across the miombo ecoregion, plot-based studies with more dense sampling across the ecoregion are clearly needed to more broadly understand regional variation in vegetation diversity, composition and structure.


Author(s):  
Omar Cabrera ◽  
Angel Benítez ◽  
Nixon Cumbicus ◽  
Carlos Naranjo ◽  
Pablo Ramón ◽  
...  

1) Background: Neotropical montane forests represent one of the most diverse ecosystems; however, they are also the most threatened for deforestation. Our main goal is to evaluate the change in Basal Area (BA), Density and Species Composition of montane forests in the southern Ecuador and to determine the influence on some critical ecological and geomorphological factors. 2) Methods: One hundred thirty-two temporary plots of 400 m2 each were installed; we identified and measured all trees> 10 cm DBH. We modeled species diversity (Fisher’s alpha) change in relation to climatic, elevational and geomorphological gradients with GLM and Kruskall-Wallis analyses. The change in composition was determined using Cluster Analyses (BIOENV analysis followed by a LINKTREE procedure). Non-metric multidimensional scaling (NMDS) was used to analyze changes across climatic and geomorphological gradients. Finally, we used SIMPER analysis to identify the species that contributed most to the dissimilarity among the different elevations. 3) Results: Formation of floristic groups was influenced by altitude, temperature and Isothermality; physiographic province, great landscape, geological landscape and lithology. Plots located in low hills have higher alpha diversity with respect to the high hills and dissected mountains. 4) Conclusions: The elevation is first hierarchical factor responsible of the division of structural and floristic groups. Plots located on the whitish tuff have a higher alpha value diversity compared with plots in andesitic tuffs. Wettest quarter (> 839 mm) and Isothermality (> 90.5) are the climatic factors that driven de floristic divisions.


2017 ◽  
pp. 17
Author(s):  
Enrique Valente Sánchez-Rodríguez ◽  
Lauro López-Mata ◽  
Edmundo García-Moya ◽  
Ramón Cuevas-Guzmán

In this paper we describe the structure, floristic composition and woody (tree and shrub) species diversity of a cloud forest at Cuzalapa, Sierra de Manantlán, Jalisco. Two localities with four 2,500 m2 plots each were established at El Durazno and La Pareja. All species present in the plots were identified and recorded, and their diameters at breast height (DBH ≥ 3cm) and heights measured. Forest structure is described using the relative values of density and basal area; in addition, a diagram  of forest profile was drawn for each plot. Among-plot similarity was assessed with Sørensen 's Index. Species diversity was evaluated using Shannon-Wiener 's, Simpson's, and Fisher's α indexes. In the total sampled area (2 ha) 2,086 individuals  belonging to 101 species (including two new records for the flora de la Sierra de Manantlán, Sapranthus foetidus and AIchornea  latifolia), distributed in 75 genera and 44 farnilies, were recorded. The families with the largest numbers of species were:  Leguminosae (8), Solanaceae and Fagaceae (7 each), Moraceae and Compositae (6 each), Lauraceae (5), and Rubiaceae (3).  Tree density at El Durazno and La Pareja was 1,084 and 1,002 trees ha-', and basal area was 38.7 and 31.9 m2 ha-', respectively.  At both localities, Styrax radians had the highest relative importance value. Forest structure and species composition at both  localities correspond to tracks of transitional forest between early to intermediate stages, which results from recurrent anthro- pogenic disturbances such as logging 50 years ago. Species diversity in Cuzalapa is one of the highest ever recorded for cloud  forests of Mexico, which presumably is a consequence of anthropogenic and natural disturbances. Both kind of disturbances  are important forces in maintaining the structure, species composition, and high species diversity in this cloud forest.


2021 ◽  
Author(s):  
Narasimha Hegde ◽  
Shrikanth Vasudev Gunaga ◽  
Hans Joosten

Abstract Sacred forests are of immense value for their ecosystem functions. Traditional indigenous conservation practices have helped maintaining biological diversity over centuries and have resulted in the preservation of some of the best patches of natural vegetation. Exclusive taxa find refuge in the micro-climatic conditions of sacred groves and many rare species are found here. Ten sacred swamps and ten non-sacred swamps in the central Western Ghats region, India, with a similar distance from roads, village settlements, or commercial orchards and with nearly the same size, were compared with regard to their species composition, floristic structure, diversity, occurrence of amphibians, odonates and birds. In the sacred swamps, 122 plant species from 99 genera and 58 families occur against 83 species from 72 genera and 47 families in the non-sacred swamps. Tree stem density was 277 individuals/ha in sacred swamps against 158.4 in non-sacred swamps. Average basal area was 47.57 m 2 /ha in sacred swamps and only 14.60 m 2 /ha in non-sacred swamps. Sacred swamps have higher number of endemic species (28%) when compared to non-sacred swamps. We conclude that the traditional belief system of treating the swamps as sacred has helped to protect these ecologically important forests.


Forests ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1207
Author(s):  
Soyeon Cho ◽  
Youngjin Kim ◽  
Sangyeop Jung ◽  
Yeonsook Choung

Sasa spp., monocarpic dwarf bamboos, are known to form recalcitrant understories, lower species diversity, and hinder forest development. Sasa borealis distributed throughout Korea showed a phenomenon of synchronized dieback after large-scale synchronized flowering nationwide around 2015. Therefore, we conducted this study to take advantage of the rare event and add prevailing activity of wild boars and culm removal to elucidate whether they promote the regeneration of a long-term suppressed forest. We set permanent plots in forests with different understory types, and tracked the vegetation change in 5 years with respect to species composition, tree regeneration, and S. borealis reestablishment. This study focused on comparison between plots established after mass flowering. In flowering stands, we found the species diversity increased significantly with increase in species evenness, but not with recruitment of new species. Furthermore, the seeds of mass-produced bamboo germinated, and the seedling abundance was found to increase considerably. In stands rooted by wild boar, species diversity increased through the recruitment of new species, including tree species. It increased the abundance of shrub and perennial herbs, while it suppressed the reestablishment of S. borealis. Although rooting effect was independently significant regardless of flowering, the synergistic effect of rooting and flowering on forest regeneration was outstanding. Wild boar seemed to function as a remover of dead culms and a breaker of remaining underground mats as well as a seed disperser. Consequently, the species composition became similar to the reference stands. However, culm cutting caused negative effects by facilitating S. borealis to re-occupy or resprout. Overall, as the wild boar population increases, the positive effect can be expected to enhance. At landscape scale, considering several factors such as flowering and non-flowering, and population size of wild boar, the long-term suppressed forests by S. borealis are projected to regenerate with mosaic forests.


1988 ◽  
Vol 18 (11) ◽  
pp. 1443-1456 ◽  
Author(s):  
Björn Hånell

The objective of this investigation was to determine a method for grouping and classifying peatlands in Sweden on the basis of site quality after drainage. Initially, sites were grouped in six vegetation types, defined by the presence and abundance of certain species in the field layer. Then, pure and mixed stands of mainly Pinussylvestris, Piceaabies, and Betulapubescens, for which the original vegetation type was known, were investigated. Data from temporary sample plots on these previously drained areas were used to reconstruct stand development after drainage. The reconstruction was based on single-tree functions derived from regression analysis. A computer routine was used to calculate stand yield in the period between ditching and data collection. With the use of this productivity analysis, the initial classification into vegetation types was revised and expanded to eight site types. From the same analysis, stand functions for form height and basal area increment were derived. These functions were used to calculate forest productivity on peatlands by simulation of postdrainage stand development. For each site type, postdrainage productivity was calculated for different climatic conditions and expressed in cubic metres per hectare annually. The accuracy of the productivity figures is discussed. A key for determining site types is presented.


2007 ◽  
pp. 23-31
Author(s):  
T. V. Kotova ◽  
G. N. Ogureeva

The means for improving of the information capacity of ecological maps have been discussed with special accent on zoocomponent usually underestimated. The concept of ecoregion has been applicated in the course of work on the new map "Bioms of Russia" (S 1 : 8 000 000). Three levels of mapping units has been proposed: 1) zono- and orobioms, 2) ecoregions, 3) regional bioms. The first one is based upon the dominance of one or several zonal vegetation types, zoocomponent being characterized by the share of different vertebrate classes in species diversity of animal population. The concept of ecoregion reflects provincial features of subdivisions such as formation diversity, ecological-coenotic spectra of plants, trophic-demension groups, genera diversity of animal population, presence of endemic species and relic communities. Regional biom (main mapping unit) is characterized by the dominating growth forms, coenotical composition of plant formations and by the original combinations of types of territorial animal groupings with the enumeration of prevailing types and their species composition.


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