scholarly journals Community Composition and Distribution Pattern of Herbaceous Flora in Holi Area of District Chamba in Himachal Pradesh

2020 ◽  
Vol 7 (1) ◽  
pp. 013-020
Author(s):  
Kehar Singh Thakur ◽  
◽  
Munesh Kumar ◽  
Rajan Bawa ◽  
Anita Kumari ◽  
...  
Keyword(s):  
Distribution Pattern ◽  
Dominant Species ◽  
Basal Area ◽  
Quantitative Information ◽  
Himachal Pradesh ◽  
Importance Value Index ◽  
Importance Value ◽  
North West ◽  
The North ◽  
The Mean

The present study was carried out in Holi Forest Range of district Chamba, which is the north-west district of Himachal Pradesh and is located between latitude 32o17’412’’ to 32o26’541’’N and longitude 76o31’504’’ to 76o35’385’’E. The territory is completely mountainous with altitude varying from about 2,000 feet (610 m) to about 21,000 feet (6,400 m) above the mean sea level. The quantitative information of herbs was collected from different sites i.e., Deol, Kut, Dal, Lahaud Dhar. Frequency (%), Density (plants m-2), Basal Area (cm2), Importance Value Index (IVI) and A/F ratio of plant species at different sites were recorded. Poa alpina was found to have highest frequency (90%) closely followed by Jurinea dolomiaea (80%) and Biebersteinia odora has the lowest frequency of 10%. Poa alpina has the highest density (60.6 plants m-2) at Dal followed by Gentiana kurrooa (35.8 plants m-2). Moschela esculenta was found to have highest basal area (1.234 cm2) at Kut. Viola serpens was the dominant species with highest value of IVI (78.77) closely followed by Poa alpina (65.91), Gentiana kurrooa (65.37) and Jurinea dolomiaea (65.36). Most of the species were distributed randomly followed by contagious pattern of distribution and least species were reported for regular distribution pattern.

scholarly journals Comparison of true mangrove stands in Dudepo and Ponelo Islands, North Gorontalo District, Indonesia

2018 ◽  
Vol 20 (1) ◽  
pp. 259-266
Author(s):  
FAIZAL KASIM ◽  
MIFTAHUL KHAIR KADIM ◽  
SITTI NURSINAR ◽  
ZULKIFLI KARIM ◽  
ALDIN LAMALANGO
Keyword(s):  
Similarity Index ◽  
Basal Area ◽  
Current Status ◽  
Survey Method ◽  
Landsat 8 ◽  
Importance Value Index ◽  
Importance Value ◽  
Mangrove Species ◽  
Rhizophora Apiculata ◽  
The Mean

Kasim F, Kadim MK, Nursinar S, Karim Z, Lamalango A. 2019. Comparison of true mangrove stands in Dudepo and Ponelo Islands, North Gorontalo District, Indonesia. Biodiversitas 20: 259-266. This study aimed to investigate and compare the current status of mangrove areas, as well as the composition and species diversity of mangrove stands in both regions of Dudepo and Ponelo Islands. The results showed that the mangrove areas calculated using the segmentation method in classifying image of Landsat-8 OLI (acquisition on September 2017) were 279.46 ha (Dudepo Island) and 113.35 ha (Ponelo Island) respectively. A total of 13 species of true mangrove were recorded from both islands, using survey method from 9 transect lines (TL), with a distance ranging from 40 to 210 meters (1-6 quadrats) per transect. The mean densities of trees were 2133 ± 329.78 ha-1 (Dudepo Island) and 2111 ± 234.28 ha-1 (Ponelo Island), while those of saplings and seedlings were 58 ± 13.48 ha-1 and 1425 ± 113.96 ha-1 (Dudepo Island), and 79 ± 14.51 ha-1 and 2963 ± 443.22 ha-1 (Ponelo Island). The mean diameter and basal area were 19.73 ± 10.65 cm and 84.22 ± 67.67 m2ha-1 (Dudepo Island), 17.04 ± 1.46 cm and 60.07 ± 15.12 m2ha-1 (Ponelo Island), respectively. The Importance Value Index (IVI) ranged between 3.97-114.87 (Dudepo Island) and 6.04-82.18 (Ponelo Island). The dominant and codominant species based on IVI in both islands were Rhizophora apiculata Blume and R. stylosa Griff. The indexes of diversity, richness, and evenness of mangrove species in both islands were 0.34-1.70, 0.48-1.18, 0.47-0.94 (trees), 0.00-1.10, 0.00-1.82, 0.00-1.00 (saplings), and 0.00.-1.48, 0.00-1.44, 0.72-1.00 (seedlings), respectively. The Bray-Curtis similarity index between Dudepo and Ponelo Islands, based on the overall values of community attributes, was 0.75.

scholarly journals How Timber Harvest Affects the Structure and Diversity of a Montane Forest in Southern Mexico

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 895
Author(s):  
Nayely Martínez-Meléndez ◽  
Neptalí Ramírez-Marcial ◽  
Pablo Martínez-Zurimendi ◽  
Manuel J. Cach-Pérez ◽  
José G. García-Franco
Keyword(s):  
Species Richness ◽  
Dominant Species ◽  
Basal Area ◽  
Timber Harvest ◽  
Montane Forest ◽  
Control Treatment ◽  
Importance Value Index ◽  
Importance Value ◽  
Southern Mexico ◽  
Timber Extraction

Timber extraction directly affects forest structure by opening the canopy, reducing the density and volume of dominant species, and transforming the composition, diversity, and functioning of the forest. We analyze the richness, diversity, and basal area of tree species in a pine–oak montane forest under two stages of the Silvicultural Development Method (thinning and liberation cut treatments) in comparison with remnants of forest considered to be control treatment in the Ocotones forest. Timber extraction began 14 years previously but its effect on the tree structure has not been studied to date in this area. We quantified and measured all the trees with a diameter at breast height >5 cm in 12 0.1 ha circular plots in each treatment. Diversity (Hill numbers) and the importance value index were calculated in each treatment. Observed species richness did not differ between treatments; Pinus oocarpa Schiede ex Schltdl. and Quercus sapotifolia Liebm. were the dominant species regardless of treatment. The principal differences in density and basal area among the treatments were found between the small oaks and small pines. In general, tree density recovered in managed areas because of newly recruited pines and re-sprouting oaks. Although no significant reduction in species richness was detected between treatments, species composition and vegetation structure were modified by the extraction of pine timber and the permanence of many large oaks. Silvicultural treatments appear to create conditions favorable to the maintenance of species richness. The silvicultural interventions in the site meet the objectives of timber production, regeneration, and biodiversity conservation; however, the question of how long the forest can maintain its species diversity and structure after timber extraction remains to be addressed.

scholarly journals COBERTURA Y ESTRUCTURA DE LOS BOSQUES DE MANGLE EN LA BAJA GUAJIRA, CARIBE COLOMBIANO

2016 ◽  
Vol 40 (2) ◽  
Author(s):  
Alianis M. Orjuela Rojas ◽  
Carlos A. Villamil ◽  
Adolfo Sanjuan Muñoz
Keyword(s):  
Forest Cover ◽  
Basal Area ◽  
Avicennia Germinans ◽  
Aerial Photographs ◽  
Mangrove Forests ◽  
Importance Value Index ◽  
Importance Value ◽  
The North ◽  
Conocarpus Erectus ◽  
Mangrove Trees

cover and structural attributes of mangrove forests in the Baja Guajira were estimated and identified. Forest cover was estimated from ASTER images and aerial photographs. The forest structure was evaluated along transects which were 10 m broad and as long as the width of the mangrove fringe. In each transect mangrove trees were identified and counted. The total height and the diameter at breast height (DBH) of the trees were measured and subsequently the basal area, density and Importance Value Index (IVI) calculated. The estimated mangrove cover of the Baja Guajira was 59.9 ha. The most frequent and dominant species was Laguncularia racemosa (0.54 m2.ha-1). Rhizophora mangle was present in 75 % of the stations, while Avicennia germinans was only found in the north of the study area. The highest average heights and diameters for R. mangle, L. racemosa and A. germinans were determined in Rincón Mosquito (12.9±2.3 m and 22.4±11.2 cm), Puerto Brisa (12.2±5.3 m and 20.8±9.8 cm) and La Enea (13.8± 4.3 m and 23.8±14.8 cm), sectors with a constant fresh water supply. The less developed forest, a monospecific forest of Conocarpus erectus, was observed in Dibulla station, with height and diameter averages of 2.8±0.6 m and 3.0±0.9 cm. In terms of natural regeneration, L. racemosa presented the highest proportion of seedlings in the study area, R. mangle was found in stations partly flooded and A. germinans had the highest density of seedlings and propagules at La Enea station.

scholarly journals On tho proportions of the prevailing winds, the mean temperature, and depth of rain in the climate of London, computed through a cycle of Eighteen Years, or periods of the Moon’s declination

1843 ◽  
Vol 4 ◽  
pp. 300-300
Keyword(s):  
The Moon ◽  
Fair Weather ◽  
North West ◽  
West Wind ◽  
North East ◽  
East Wind ◽  
The North ◽  
The Common ◽  
The Mean ◽  
Solar Influence

In this paper the author investigates the periodical variations of the winds, rain and temperature, corresponding to the conditions of the moon’s declination, in a manner similar to that he has already followed in the case of the barometrical variations, on a period of years extending from 1815 to 1832 inclusive. In each case he gives tables of the average quantities for each week, at the middle of which the moon is in the equator, or else has either attained its maximum north or south declination. He thus finds that a north-east wind is most promoted by the constant solar influence which causes it, when the moon is about the equator, going from north to south; that a south-east wind, in like manner, prevails most when the moon is proceeding to acquire a southern declination ; that winds from the south and west blow more when the moon is in her mean degrees of declination, going either way, than with a full north or south declination ; and that a north-west wind, the common summer and fair weather wind of the climate, affects, in like manner, the mean declination, in either direction, in preference to the north or south, and most when the moon is coming north. He finds the average annual depth of rain, falling in the neighbourhood of London, is 25’17 inches.

scholarly journals Biochemical parameters variations with season, age, sex, parity and pregnancy in crossbred goats raised in Tiaret, Algeria

2021 ◽  
Vol 8 (1) ◽  
pp. 69-79
Author(s):  
Berrani Abdelkader ◽  
Meliani Samia ◽  
Bourabah Akila
Keyword(s):  
Significant Influence ◽  
Biochemical Parameters ◽  
Physiological State ◽  
Mean Values ◽  
North West ◽  
The North ◽  
Nutritional Conditions ◽  
Physiological Stage ◽  
The Mean ◽  
Calcium And Phosphorus

Abstract The aim of this study was to determine the influence of season, age, sex, parity and gestation status on some biochemical parameters in local cross-bred goats raised in Tiaret, Algeria. Ninety cross bred local goats, from 2019 to 2020, aged between nine and seventy-two months at different physiological stage were used. Animals belong to different farms in Tiaret located at the north-west Algeria (35°22’ N, 1°19’ E). The mean values of triglycerides, creatinine and calcium were significantly (p<0,05) higher in winter than in spring. The physiological state of the goat had a significant influence (p<0,05) on cholesterol, urea, total proteins, calcium and phosphorus, with a high average values in non-pregnant goats, while triglycerides and globulin had significant higher values in postpartum and pregnant femals, respectively. In our work, parity had a significant influence (p<0,05) on cholesterol, calcium and phosphorus, with high average values in young goats and a significant influence (p<0,05) on triglycerides and creatinine with high average values in primiparous ones. Age significantly influenced (p<0,05) cholesterol, triglycerides, total protein, calcium and globulin. The results obtained from this study could serve as reference values for the local goats and other regions or countries with similar climatic and nutritional conditions.

SEDIMENTARY PROVENANCE STUDIES IN AUSTRALIAN BASINS USING NEODYMIUM MODEL AGES

1994 ◽  
Vol 34 (1) ◽  
pp. 320
Author(s):  
D. J. Whitford ◽  
P.J. Hamilton ◽  
J. Scott
Keyword(s):  
Sedimentary Rock ◽  
Quantitative Information ◽  
Basin Evolution ◽  
North West ◽  
Provenance Studies ◽  
Earth’S Mantle ◽  
The North ◽  
Sedimentary Provenance ◽  
Over Time ◽  
Eromanga Basin

An understanding of the tinting of basin evolution is fundamental to the development of successful play concepts. The Sm-Nd geochronometer can be used to determine quantitatively the `average' age at which segments of continental crust have been extracted from the earth's mantle. Variations in Nd model ages within sedimentary rock sequences indicate changes in sedimentary provenance over time and provide a potential correlation tool.In the Eromanga Basin, there is a distinct lithological contrast between the main reservoir unit, the Jurassic Hutton Sandstone, and the overlying Birkhead Formation. The quartz-rich Hutton Sandstone is characterised by relatively old Nd model ages, generally within the range 1.3–1.5 Ga. In contrast the lithic-rich Birkhead Formation has much younger model ages, generally Neodymium model ages measured in mudstones within the Flag Sandstone from the Harriet Field in the Barrow Sub-basin of the North West Shelf, range from 2.1–2.5 Ga. The old ages are consistent with the sediments being derived from the Archaean shield areas and the younger Proterozoic complexes of Western Australia. Tentative correlations based on model ages between mudstone units from two wells are consistent with correlations based on heavy mineral suites.Neodymium model ages have application to correlation at both regional and local scales within basins. Reliable information can be obtained on both sandstones and mudstones on samples as small 50 g. Potentially they can provide important quantitative information complementary to that derived from more conventional approaches.

Phocanema decipiens (Nematoda: Anisakinae): experimental infections in marine copepods

1982 ◽  
Vol 60 (4) ◽  
pp. 502-509 ◽  
Author(s):  
Gary McClelland
Keyword(s):  
Gravid Female ◽  
Mature Female ◽  
Cyclopoid Copepod ◽  
Calanoid Copepods ◽  
North West ◽  
The North ◽  
The Family ◽  
The Mean ◽  
Mean Time ◽  
Marine Copepods

Gravid female Phocanema decipiens were recovered from the stomachs of freshly killed harbour (Phoca vitulina) and grey seals (Halichoerus grypus). Ova dissected from the nematodes were incubated in seawater and the mean time to hatch varied from 8 days at 20 °C to 52 days at 5 °C. Posthatch survival of ensheathed larvae in seawater varied from 48 h at 20 °C to 140 days at 5 °C. Fifteen species of copepods collected from the North West Arm, Halifax, N.S., were exposed to freshly hatched larvae of P. decipiens. Exsheathed larvae of the parasite were subsequently detected in the haemocoel of 12 harpacticoid species including Danielsennia typica, Tisbe furcata, Ameira longipes, Enhydrosoma curticauda, and various undescribed species of the genera Halectinosoma, Tisbe, Alteutha, and Phyllothallestris and the family Diosaccidae. Phocanema decipiens also occurred in a cyclopoid copepod (Paracyclopina sp.) but calanoid copepods (Eurytemora sp. and Pseudocalanus sp.) did not become infected. The heaviest infections occurred in mature female copepods and prevalence and intensity of infection varied with host species. Adult male copepods and fifth copepodite females were lightly infected. Infected copepods survived for 3–7 days at 15 °C, 10–15 days at 10 °C, and 20–35 days at 5 °C. During the course of infection, larval P. decipiens grew an average of 60% and maximum of 130% in length but underwent little or no morphological change.

scholarly journals Fuel beds variation of coastal tropical freshwater forested wetlands in three disturbance regimes at La Encrucijada, Biosphere Reserve, Mexico

2020 ◽  
Author(s):  
Romeo de Jesús Barrios Calderón ◽  
Dulce Infante Mata ◽  
José Germán Flores Garnica ◽  
Jony Ramiro Torres Velázquez ◽  
Zulia Mayari Sánchez-Mejía ◽  
...  
Keyword(s):  
Forest Fires ◽  
Biosphere Reserve ◽  
Basal Area ◽  
Forested Wetlands ◽  
Material Surface ◽  
Importance Value Index ◽  
Importance Value ◽  
High Accumulation ◽  
Horizontal Structure ◽  
Tropical Freshwater

Abstract Background: Tropical freshwater forested wetlands in coastal regions are rapidly disappearing, one of the causes is forest fires. This is caused by high accumulation of fuel beds that can vary in origin and type. Therefore, the objective of this study was to characterize the fuel beds in tropical freshwater forested wetlands with three different level of disturbance at El Castaño, La Encrucijada Biosphere Reserve.Methods: Seventeen sampling units were used to described the strates of forest fuel beds (canopy, sub-canopy and understory) in both the vertical and horizontal stratum. Quantity and quality of dead (fallen woody material, surface litterfall and fermented litterfall) fuels were characterized using the planars intersections technique.Results: A total of eight tree species, two shrubs, five lianas and two herbaceous species were found in tropical freshwater forested wetlands. The vertical structure concentrates the highest proportion of trees between 2 and 12 m high, including the first two defined height classes. The horizontal structure denotes a higher percentage of trees with a normal diameter between 2.5 to 7.5 cm (61.4%) of the total. The sites none disturbance presented the highest arboreal density (2,686 ind. ha− 1), however the highest basal area was found in the sites with medium disturbance (39.41 m2 ha− 1). The richness and diversity of species shows that the Fisher, Margalef, Shannon and Simpson α indices were higher in the sites undisturbed, while the Berger-Parker index shows greater dominance in the sites high disturbance. Pachira aquatica Aubl. was the species with the highest importance value index, and contributes the most to the fuel beds. The average accumulation of dead fuel beds was higher in sites with high disturbance (222.18 ± 33.62 t ha− 1), with the largest accumulations of woody fuels occurring in the 1 h, 10 h and 1000 h classes, the latter in a state of fermentation.Conclusions: It’s important to consider the probability of occurrence of surface fires is high. In these tropical freshwater forested wetlands, independent of disturbance, underground fires have the same probability and the intensity will depend on the depth of the organic matter layer. This study contributes define fire-prone areas in these ecosystems. The results are of great importance to design fire prevention strategies.

scholarly journals Keanekaragaman Coccinellidae Predator Pada Beberapa Ekosistem Perkebunan di Kabupaten Dharmasraya

2019 ◽  
Vol 10 (2) ◽  
pp. 157-168
Author(s):  
Siska Chiko Efendi ◽  
Yaherwandi Yaherwandi ◽  
Ade Noferta ◽  
Aditya Muhammad
Keyword(s):  
Species Diversity ◽  
Dominant Species ◽  
Wiener Index ◽  
Simpson Index ◽  
Importance Value Index ◽  
Importance Value ◽  
Important Value Index ◽  
Sweep Net ◽  
Species Importance

The objectives of this research were to study the species diversity and to determine the dominant species of lady bird beetle predators in high land plantation ecosystem in West Sumatera. The samples were taken by hand collection and sweep net. The data of species diversity were analyzed using Shannon-Wiener index, evenness of species were analyzed by Simpson index, and  dominant species using important value index. The results showed that there were 91 individuals predator found which consisted of 7 species. The highest  species diversity (1.74) and evenness (0.89) were found in Pulau Punjung. The lowest diversity and evennes (1,40) and (0,75) was found in Koto Besar. The highest  species importance value index was 1,00, that was Menochillus sexmaculatus.

scholarly journals Population status of the tree Sacoglottis holdridgei (Humiriaceae) at Isla del Coco National Park, Costa Rica

2016 ◽  
Vol 64 (1) ◽  
pp. 263
Author(s):  
Luis Guillermo Acosta-Vargas
Keyword(s):  
National Park ◽  
Basal Area ◽  
Forest Monitoring ◽  
Diameter Distribution ◽  
Population Status ◽  
Importance Value Index ◽  
Importance Value ◽  
Data Points ◽  
Using Data ◽  
Annual Mortality

<p>Isla del Coco is the only oceanic island in the Eastern Pacific with humid tropical climate. Its forests have a particular structure with a unique array of plant species and high endemism. There are few studies on the flora or forest monitoring on the island.  The population structure of <em>Sacoglottis holdridgei</em> was analyzed using data from six years with data points taken in 2006 and 2012, including sampling of regeneration in 2012.<em> Sacoglottis holdridgei </em>was the most important tree species, presenting in 2012 the highest Importance Value Index (190.7±21.8), abundance (158.5±40.3 Nha<sup>-1</sup> or 39.5 % of the forest) and basal area (15.6 m<sup>2</sup>ha<sup>-1 </sup>or 72.9 % of the forest). It was present in all three height strata with dominance in the highest. Annual mortality was reported at 3.3 % and recruitment at 1.2 %. The diameter distribution of forest fits the inverted <em>J</em> model, but not for the reported species of which only <em>S. holdridgei</em> tends to adjust for DBH&gt;40 cm. Regeneration fitted the inverted<em> J</em> model with values below those reported for continental forests. Even though it was the dominant species, <em>S. holdridgei </em>showed low regeneration values. This particular condition, give way hypotheses related to the introduction of species, species biology and climate change which could influence the future development of <em>S. holdridgei</em> and forests of Isla del Coco.</p><div> </div>

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