scholarly journals Effect of forest fire on floristic composition, structure, dominance and species richness in subtropical pine forest of Ponda watershed, Rajouri, J&K

2014 ◽  
Vol 15 (1&2) ◽  
pp. 61-68
Author(s):  
Junaid Ahmed ◽  
Sanjay Sharma

Forest fires have profound impacts on physical environment including land cover, land use, forest ecosystem and biodiversity. In the present study the effect of fires on floristic composition, structure, dominance and species richness in subtropical pine forest of Ponda watershed, Rajouri, J&K, lying at an altitude range of 800 m to 1000 m above mean sea level, was assessed. The forests in the study area were divided into two strata i.e., burnt and un-burnt forest. Random sampling was carried out by laying out forty sample plots in all, with twenty sample plots in each strata covering burnt and unburnt forest sites of the study area. The plot dimensions of 20m x 20m were used for studying trees and 5m x 5m for shrubs (laid within the plots for trees). The density, basal area and IVI along with diversity and concentration of dominance of trees and shrubs in both forest sites were studied. Similarity index was also calculated for burnt and unburnt forest of the study area. The results show that the total density and total basal area of trees and shrubs was highest in un-burnt forest sites with density values of 468.75 and 5284 individuals/ha and 85.33 m2/ha and 25.42 m2/ha, respectively. The results on the basis of the comparison of IVI values of all species in both forest stands also reveal that the respective dominant tree and shrub species were Pinus roxburghii and Carissa opaca. The calculated values of Shannon-Wiener, Margalef and Menhinick indices i.e. 1.93, 2.53 and 0.82 for trees and 1.80, 2.08 and 0.44 for shrubs, respectively, reveal that the species richness and diversity was high for unburnt forest stand whereas, Simpson’s index value of tree (0.48) and shrub (0.75) show that an concentration of dominance was highest in burnt forest stands. The calculated value of Sorenson’s and Jaccard’s index of similarity for trees (0.60 and 0.43) was maximum as compare to shrubs (0.47 and 0.31) which shows that forest fire have profound effect on shrub than trees.

FLORESTA ◽  
2001 ◽  
Vol 31 (12) ◽  
Author(s):  
Raquel R.B. Negrelle ◽  
Ramoci Leuchtenberger

São apresentados dados de levantamento florístico-estrutural realizado em remanescente de Floresta Ombrófila Mista (Mata da Fortaleza) no Parque Estadual de Vila Velha, Ponta Grossa - PR (23° 3’ S, 50° 15’ W). Na aplicação do método de quadrantes (75 pontos) foram registrados 300 indivíduos arbóreos (DAP > 15 cm), sendo 11 arvores mortas em pé. Dentre os indivíduos vivos, catalogaram-se 67 morfo-espécies sendo 37 identificadas em nível de espécie, 15 em nível de gênero, 7 em nível de família e 8 não puderam ser identificadas. Para estes indivíduos detectou-se um valor de diversidade H’=3,538 (var. = 0,00413), densidade total de 658 árvores/hectares e área basal total de 32,97 m2. Cerca de 59 % dos indivíduos amostrados foram classificados como macrofanerófitos e 41% como mesofanerófitos, não ocorrendo registro de nanofanerófitos. As espécies de maiores valores estruturais foram Ocotea odorifera (VI=40,19), Araucaria angustifolia (VI= 30,39), Ocotea acutifolia (VI=19,0) e Luehea divaricata (VI=18,44). Floristic composition and structure of an Araucarian forest remnant Abstract Data from a floristic and structural survey in an araucarian forest remnant (called Mata da Fortaleza) in the Vila Velha State Park (Ponta Grossa - PR - 23° 3’ S, 50° 15’ W) are presented. With the application of the point-centered quarter method (75 sampling points), 300 trees (dbh > 15cm) were sampled, including 11 dead trees. Within the alive individuals, 67 morpho-species were detected, 37 identified at a species level, 15 at a generic level, 07 at a family level and 8 were not identified. For the alive component the diversity was H’=3.538 (var. = 0.00413), total density was 658 trees/hectare and the total basal area was 32.97 m2. Almost 59 % of all sampled individuals was classified as macrofanerophyte and 41% as mesofanerophyte, with no register of nanofanerophytes. The species with the greatest importance value were: Ocotea odorifera (40,19), Araucaria angustifolia (30,39), Ocotea acutifolia (19,0) and Luehea divaricata (18,44).


2020 ◽  
Vol 14 (5) ◽  
pp. 1558-1575
Author(s):  
Ismaila Coly ◽  
Tahirou Charles Diatta ◽  
Daouda Ngom ◽  
Aliou Badji ◽  
Omar Gueye

L’agriculture occupe une place très importante dans l’arrondissement de Tendouck. Pour augmenter leurs rendements, les agriculteurs laissent délibérément dans leurs champs certaines espèces ligneuses. Cette étude a pour objectif général de contribuer à une meilleure connaissance des caractéristiques des parcs agroforestiers du département de Bignona. Pour ce faire, une placette de 2500 m² (50 mx50 m) a été installée dans les champs de chaque agriculteur retenu dans un échantillon de 98 agriculteurs. Cet échantillon est réparti entre les différentes communes de l’arrondissement au prorata de leur poids démographique soit 16 ; 21 ; 22 ; 30 et 9 placettes respectivement dans les communes de Balinghore, Diégoune, Kartiack, Mangagoulack et Mlomp. La flore dans l’arrondissement de Tendouck est riche de 53 espèces réparties en 45 genres relevant de 20 familles botaniques. Au niveau de l'arrondissement de Tendouck la densité des arbres des parcs agroforestiers est de 42 pieds/ha, la surface terrière de 3,21 m²/ha et le taux de recouvrement de 18,82%. Ces parcs sont très diversifiés avec un indice de Shannon de 3,91 et un indice de Pielou de 0,79. Le taux de régénération y est très important (88,19%). La structure par classes de hauteur du peuplement ligneux des parcs agroforestiers révèle une prédominance des jeunes individus avec 24,73% des individus appartenant à la classe de hauteur [2-4 m]. La classe de diamètre la plus représentée est [5-20 cm] avec 42, 99% des individus. Ces résultats constituent une base pour une gestion rationnelle et durable de ces écosystèmes en vue de permettre aux agriculteurs de mieux tirer profit de leurs services dans l’arrondissement de Tendouck. Il apparait ainsi judicieux de poursuivre cette étude dans les autres départements de la Basse Casamance en vue de disposer d’une base de données des parcs agroforestiers de cette zone éco géographique.Mots clés: Champs, composition floristique, structure, agriculteurs, caractéristiques structurales   English title: Characteristics of the woody flora and vegetation in the agroforestry parks of the Tendouck district (Lower Casamance, Senegal)Agriculture occupies a very important place in the district of Tendouck. In order to increase their yields, farmers deliberately leave certain woody species in their fields. The general objective of this study is to contribute to a better knowledge of the characteristics of agroforestry parks in the Bignona district. To this end, a 2500 m² (50 mx50 m) plot was installed in the fields of each farmer selected from a sample of 98 farmers. This sample is distributed among the different communes of the district in proportion to their demographic weight, therefore 16; 21; 22; 30 and 9 plots respectively in the communes of Balinghore, Diégoune, Kartiack, Mangagoulack and Mlomp. The flora in the district of Tendouck is rich of 53 species divided into 45 genera belonging to 20 botanical families. At the level of Tendouck district, the density of trees in agroforestry parks is 41.55 trees/ha, the basal area of 3.21 m²/ha and the rate of covering of 18.82%. These parks are very diversified with a Shannon index of 3.91 and a Pielou index of 0.79. The regeneration rate is very high (88.19%). The height class structure of the woody stand in the agroforestry parks reveals a predominance of young individuals with 24.73% of the individuals belonging to the height class [2-4 m]. The most represented diameter class is [5-20 cm] with 42.99% of the individuals. These results provide a basis for rational and sustainable management of these ecosystems with a view to improving the living conditions of farmers in the Tendouck district. It therefore seems advisable to continue this study in the other departments of Lower Casamance in order to have a data of the agroforestry parks of this eco-geographical area.Keywords: Fields, floristic composition, structure, farmers, structural features  


2020 ◽  
Author(s):  
Annissa Muhammed ◽  
Eyasu Elias

Abstract BackgroundBale mountains national park (BMNP) is one of the 34 International Biodiversity Hotspots that comprise a variety of life forms. However, it faces a critical challenge from subsistence farming and overgrazing. This study was made to analyze the effects of landscape change on floristic composition, diversity, and structure in BMNP. The vegetation and environmental data were collected from 96 plots that were laid along 8 line transects. Vegetation hierarchical clustering and landscape structural analysis was made using R software version 3.5.2 and FRAGSTATS version 4.2.1, respectively. ResultsA total of 205 species that belongs to 153 genera and 71 families were identified. The overall Shannon diversity and evenness index was 4.34 and 0.81, respectively. Both the species richness and Shannon diversity index were significantly higher (p < 0.05) in the edge habitat (40 ± 0.2 and 2.93 ± 0.2, respectively) than the interior (25 ± 4.5 and 2.43 ± 0.4, respectively). Conversely, the basal area was lower in the interior habitat (173.79 m2 ha-1) than the edge (64.15 m2 ha-1). Moreover, as AREA_MN and COA of patches increases, species richness, diversity, evenness, woody species density, basal area, DBH, and height also increases. Whereas, as PN, SHAPE_MN, ED, ENN_MN, and IJI of patches increases, those floristic compositions and structural variables decrease. ConclusionThis study revealed that BMNP is a biologically diverse and ecologically significant area that provides a variety of ecological and economic benefits to the surrounding communities and the country at large. However, its landscape is changing alarmingly and urgent restoration and conservation action needs to be taken to reverse this condition.


2019 ◽  
Vol 13 (2) ◽  
pp. 177-184
Author(s):  
Bobbymoore Konsam ◽  
Shyam S Phartyal ◽  
Nagendra P Todaria

Abstract Aims To explain how plant community copes with a recurring anthropogenic forest fire in Himalayan Chir pine forest, it is important to understand their postfire regeneration strategies. The primary aim of the study was to know: (i) how fire impact soil seed bank composition and (ii) how much soil seed bank composition differs with standing vegetation after the forest fire. Methods Soil samples were collected from burned and adjoining unburned sites in blocks using three layers down to 9 cm depth immediately after a forest fire and incubated in the net-house for seedling emergence. Same sites were revisited during late monsoon/early autumn season to know the species composition of standing vegetation recovered after a forest fire. Important Findings Soil contained viable seeds of &gt;70 species. The average seed bank density was 8417 and 14 217 seeds/m2 in the burned and unburned site, respectively. In both sites, it decreased with increasing soil depth. Overall fire had no significant impact on seed density; however, taking individual layers into consideration, fire had a significant impact on seed density only in the uppermost soil layer. The species richness of soil seed bank and standing vegetation was 73 and 100, respectively (with 35 shared species), resulting in a similarity of about 40%. In contrast, &gt;80% species in soil seed bank was found similar between burned and unburned sites. Further, there were no significant differences in species richness of standing vegetation in burned (87 spp.) and unburned (78 spp.) sites. Our results showed that fire had an insignificant impact on soil seed bank composition and restoration potential of a plant species from seeds. The understory herb and shrub plant community’s ability to form a fire-resistant viable soil seed bank and capable to recover in the postfire rainy season, explains how they reduce the risk of recurring fire damage in maintaining their population.


2011 ◽  
Vol 72 (1) ◽  
pp. 61-69 ◽  
Author(s):  
Wojciech Bąba

<p>The calcareous grasslands belong to the species-rich plant communities in Poland. Most of them are of anthropogenic origin and they need specific management (i.e. periodical cutting suckers of trees and shrubs, grazing or mowing) in order to protect their floristic diversity. Many of calcareous grasslands have been overgrown by shrubs as a result of cessation of traditional management. The aim of this study was to compare the structure and dynamics of xerothermic hazel shrub patches, which were undergoing secondary succession with patches where different management practices aiming at restoration of species-rich limestone grassland were applied. The managed plots had a significantly higher species richness than the control one. However, they strongly differed in their floristic composition from well-preserved limestone grasslands. There were also significant differences observed between both the managed plots. Too intensive management, particularly frequent mowing of herbs resulted in expansion of grass species such as <em>Brachypodium pinnatum</em> and <em>Calamagrostis arundinacea</em> and caused a sharp decline in species richness.</p><p>The species composition and turnover rate strongly depended on succesional stage (soil layer thickness) of plots at the start of the experiment. The deeper was the soil, the higher was the rate of species turnover and the smaller was the share of xerothermic and thermophilous species. The last mentioned group was dominated by species with a persistent seed bank in the soil, frequently colonizing anthropogenic habitats.</p>


2019 ◽  
Vol 14 (4) ◽  
pp. 381-397
Author(s):  
Cássio Cardoso Pereira ◽  
Fernanda de Fátima Santos Soares ◽  
Rúbia Santos Fonseca ◽  
Nathália Ribeiro Henriques ◽  
Daniel Meira Arruda

The flora of the Rupestrian Savannah (Cerrado Rupestre) is composed of widely distributed species and endemic species from high altitude rocky outcrops. The aim of this study was to characterise the floristic composition, structure and diversity of fragments of Rupestrian Savannah in south-eastern Brazil and to examine the similarity with other rupestrian cerrado vegetations and with cerrado sensu stricto on profound soils. For this, phytosociological parameters, evenness and diversity were calculated and compared with other studies. The survey exhibited 72 species, 45 genera, 30 families and high floristic similarity with cerrado on profound soils. There were no indicator species of the Rupestrian Savannah, but there were typical species of rocky environments. The basal area was significantly larger in the profound soil cerrado in relationship to the Rupestrian Savannah and evenness was lower in the Rupestrian Savannah of this study compared to others. These variables reflect the lower exploration capacity of the root of rocky environments. The highest similarity between the Rupestrian Savannah and cerrado on profound soils refers to the canga ferruginous nature, which represents the limit of the tableland of cerrado on the edge of the plateaus, allowing greater sharing of flora.


2018 ◽  
Vol 48 (1) ◽  
pp. 46-56 ◽  
Author(s):  
Layon Oreste DEMARCHI ◽  
Veridiana Vizoni SCUDELLER ◽  
Livia Carvalho MOURA ◽  
Randolpho Gonçalves DIAS-TERCEIRO ◽  
Aline LOPES ◽  
...  

ABSTRACT The Amazonian white-sand vegetation presents a set of unique features, such as the dominance of a few species, high endemism and low species richness, which differentiate it from other Amazonian forests. Soil parameters have long been recognized as the main drivers of white-sand vegetation (WSV) characteristics. However, how they influence the composition, richness and structure of this vegetation type is still poorly understood. In this study we investigated the variation in floristic composition between patches and the soil-vegetation relations in three central Amazonian WSV patches. We tested whether slight differences in soil properties are linked with differences in floristic composition, species richness and forest structure in adjacent patches. In each patch three plots of 50 x 50 m were sampled (a total of 2.25 ha). Soil samples were collected for each plot. The sampling cutoff for arboreal individuals was DBH ≥ 5 cm. We sampled a total of 3956 individuals belonging to 40 families and 140 species. In each patch only a few species were dominant, but the dominant species varied among patches. Differences among patches were significant, but plots in the same patch tended to have similar species composition. The variable sum of bases (SB) was directly related to species composition, however, species richness and forest structure were not related to soil parameters. Even small variations in soil parameters can change species composition in WSV, although these variations do not necessarily influence the richness and other structural parameters.


2001 ◽  
Vol 58 (3) ◽  
pp. 483-497 ◽  
Author(s):  
B. S. MARIMON ◽  
J. M. FELFILI ◽  
M. HARIDASAN

The floristic composition, structure, soil fertility and leaf nutrient concentrations were analysed in a monodominant forest of Brosimum rubescens Taub. located in the Areões Xavante Indigenous Reserve (14°34′S, 51°58′W). The area lies in the ecotone between Amazonian forest and cerrado in the municipality of Água Boa, Mato Grosso State, Brazil. Sixty nested plots (10 × 10m each) were located in a representative portion of the forest, giving a total sampling area of 0.6ha (40 × 150m). A total of 609 trees ≥ 5cm dbh belonging to 57 species, 46 genera and 32 families were present. The most important family was Moraceae, with B. rubescens as the dominant species with a relative dominance of 59%. The diameter distribution of B. rubescens was unbalanced, indicating an episodic recruitment that could lead to future changes in the forest structure. The high basal area per hectare of B. rubescens indicates the possibility of sustainable logging for commercial exploitation. Analysis of composite soil samples collected from the surface layer (0–10cm) of each of the 60 plots did not indicate any significant gradients in fertility within the area sampled. Mean soil pH was 4.6 and the availability of essential nutrients was very low (0.22cmol(+) kg−1 K, 0.048cmol(+) kg−1 Ca, 0.167cmol(+) kg−1 Mg, and 1.5mg kg−1 P). The higher availability of Mg in the soils in comparison with Ca was a feature observed in other monodominant forests in the Amazon region, as well as in other parts of the world. Analysis of foliar samples showed that the dominant species, B. rubescens, maintained higher foliar concentrations of K, Ca and Mg than other species in the forest. This probably indicates a competitive advantage for this species. Also, the higher concentrations of Mg in the soil did not affect its uptake of Ca or K.


2014 ◽  
Vol 62 (1) ◽  
pp. 36 ◽  
Author(s):  
Rohan Etherington ◽  
Alison Shapcott

Habitat fragmentation is considered to be one of the greatest threats to biodiversity. Species richness is predicted to decrease with decreasing patch size and increasing isolation, and this has been shown in some ecosystems. However, few studies have specifically investigated the effects of fragmentation on specific vegetation types, or compared different vegetation types within the same region. In this study, we assessed the influence of habitat fragmentation and time since fire on the floristic composition, structure and diversity of three ecosystems with varying fire proneness within the Sunshine Coast region. This study found that the tall-open forest ecosystem (RE 12.9-10.14) had higher overall species richness within fixed sample areas used for this study than did either open forest (RE 12.5.3) or gallery rainforest (RE 12.3.1), because it was composed of species typical of each of these ecosystem types. Open forest species richness was found mostly in the lower stratum, whereas gallery rainforest diversity was found in the upper stratum. Species richness decreased with increasing isolation in the open forest ecosystem where seeds are mostly abiotically dispersed. However, this study did not find strong evidence for reduced species richness within smaller patches in any ecosystem type studied; instead, finding species richness decreased with increasing patch size in the open forest ecosystem. Overall, across ecosystems, time since fire affected vegetation structure, but in fire-prone ecosystems, time since fire was not a determinant of species richness within the sites studied.


2017 ◽  
pp. 19 ◽  
Author(s):  
José A. Gallardo-Cruz ◽  
Jorge A. Meave ◽  
Eduardo A. Pérez-García

In this study we describe the structure, floristic composition, and diversity of the tropical dry forest established on the Cerro Verde (Verde Hill), located at Nizanda (Isthmus of Tehuantepec, Oaxaca, Mexico). We censused woody plants with DBH Ɛ 1 cm (upper stratum) present in 30 100-m2 plots, and in five 4-m2 subplots within each of them, those plants with height &gt; 30 cm but &lt; 1 cm DBH (lower stratum). A total of 194 species belonging to 52 families were recorded. Species richness was identical in both strata (145 species), each contributing exclusively with ca. 25% of total recorded richness. Leguminosae was the most speciose family (27), followed by Asteraceae (20) and Euphorbiaceae (18). The most frequent species were Bursera simaruba + B. aff. cinerea (not distinguished in the field), Euphorbia schlechtendalii, Pilosocereus collinsii and Capparis verrucosa. Average richness by plot was 30 species. Mean values of indices based on species richness and abundances (Berger-Parker = 0.20;  Simpson = 0.09; Fisher’s[= 9.47; Shannon = 2.78; eveness = 0.82) indicated a high diversity and consequently a low dominance in this forest. Extrapolated values showed a total (upper + lower strata) density of 23,950 ind. ha-1 (830 ind. ha-1 with DBH Ɛ 10 cm), a forest cover of 446.7%, and a basal area of 53 m2 ha-1. Mean height of those individuals accounting for 10% of the highest trees by plot was 9.1 m. Tropical dry forest structure at Cerro Verde is comparable to other Mexican communities within the seasonally dry tropical region and indicates a good conservation status. This feature, together with its particular floristic composition, makes of this area a high priority site which requires inclusion in a formal conservation scheme.


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