Tree species diversity and stand structure along major community types in lowland primary and secondary moist deciduous forests in Tripura, Northeast India   总被引：1，自引：0，他引：1  

Koushik Majumdar  Uma Shankar  Badal Kumar Datta 《林业研究》2012,23(4):553-568

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   

Mechanism and pathway of glucose transportation in a digenetic trematode Ceylonocotyle scoliocoelium     

M Bose  C R Maity  S K Ghosal  G Majumdar 《Folia parasitologica》1990,37(2):151-156

The mode of absorption, kinetics and mechanism of transportation of 14C--glucose in a digenetic trematode, Ceylonocotyle scoliocoelium were studied by culturing the trematodes under in vitro condition in Hank's saline supplemented with radioactive tracer. It was then followed separately by autoradiography and liquid scintillation. Autoradiographic study reveals that the maximum amount of glucose uptake occurs through cuticle whereas the role of intestinal canal is insignificant in this respect. Maximum cpm is recorded in the precipitate followed by TCA treatment. This is due to the presence of a protein-bound 14C-glucose which is assumed as the carrier protein. The inhibitor, phlorizin, used here presumably acts noncompetitively.  相似文献   

Sunflower response to potassium fertilization and nutrient requirement estimation     

Shu-tian LI  Yu DUAN  Tian-wen GUO  Ping-liang ZHANG  Ping HE  Kaushik Majumdar 《农业科学学报》2018,17(12):2802-2812

Field experiments were conducted in oil and edible sunflower to study the effects of potassium(K) fertilization on achene yield and quality, and to estimate the nutrient internal efficiency(IE) and nutrient requirement in sunflower production. All trials in edible sunflower and 75% trials in oil sunflower showed positive yield responses to K fertilization. Compared with control without K fertilization, the application of K increased achene yield by an average of 406 kg ha~(–1) for oil sunflower and 294 kg ha~(–1) for edible sunflower. K application also increased 1 000-achene weight and kernel rate of both oil and edible sunflower. K fertilization improved the contents of oil, oleic acid, linoleic acid and linolenic acid in achenes of oil sunflower, and increased contents of oil, total unsaturated fatty acid and protein in achenes of edible sunflower. The average agronomic efficiency of K fertilizer was 4.0 for oil sunflower and 3.0 kg achene kg~(–1) K_2O for edible sunflower. The average IE of N, P and K under balanced NPK fertilization was 22.9, 82.8, and 9.9 kg kg~(–1) for oil sunflower, and 27.3, 138.9, and 14.3 kg kg~(–1) for edible sunflower. These values were equivalent to 45.5, 14.1, and 108.1 kg, and 39.0, 8.0, and 71.7 kg of N, P and K, respectively, in above-ground dry matter required for production per ton of achenes. The average harvest index of N, P and K was 0.47, 0.56 and 0.05 kg kg~(–1) in oil sunflower, and 0.58, 0.58 and 0.14 kg kg~(–1) in edible sunflower.  相似文献   

Modelling of ring yarn unevenness by soft computing approach     

Abhijit Majumdar  Mihai Ciocoiu  Mirela Blaga 《Fibers and Polymers》2008,9(2):210-216

This paper demonstrates the application of two soft computing approaches namely artificial neural network (ANN) and neural-fuzzy system to forecast the unevenness of ring spun yarns. The cotton fiber properties measured by advanced fiber information system (AFIS) and yarn count have been used as inputs. The prediction accuracy of the ANN and neural-fuzzy models was compared with that of linear regression model. It was found that the prediction performance was very good for all the three models although ANN and neural-fuzzy models seem to have some edge over the linear regression model. The linguistic rules developed by the neural-fuzzy system unearth the role of input variables on the yarn unevenness.  相似文献   

Activities of acid and alkaline phosphatase and alanine and aspartate aminotransferase in different regions of the alimentary tract of adult White Rock cockerels     

S Majumdar  J N Panda  B P Singh 《British poultry science》1988,29(3):677-681

1. Alkaline phosphatase [EC 3.1.3.1], acid phosphatase [EC 3.1.3.2], aspartate aminotransferase [ASAT, EC 2.6.1.1] and alanine aminotransferase [ALAT, EC 2.6.1.2] were measured in mucosal homogenates of different segments of the alimentary tract of White Rock cockerels. 2. The activities of acid and alkaline phosphatases were higher in the duodenum, jejenum and caecum than the anterior segments of the alimentary tract. 3. The activity of aspartate aminotransferase was higher in the oesophagus and crop than in the caudal segments of the alimentary tract. Alanine aminotransferase activity did not show any specific pattern. 4. The increased phosphatase activities in the caudal alimentary tract indicates their involvement in the nutrient transport across the mucosa. Aminotransferases were probably involved in the synthesis of amino acids and proteins in the anterior alimentary tract.  相似文献   

Multiple Lipomas in a Bonnet Monkey (<Emphasis Type="Italic">Macaca radiata</Emphasis>)     

Nagarajan P  Venkatesan R  Kumar MJ  Seshadri SJ  Majumdar SS 《Veterinary research communications》2005,29(5):415-420

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Confirmation of rinderpest from samples of affected gums     

R. S. Kataria  S. N. Shrivastava  S. S. Majumdar 《Tropical animal health and production》1977,9(4):232-232

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Assessing Impacts of Crested Wheatgrass AND Native Species Establishment on Soil Characteristics in Reclaimed LAND Using Bayesian Posterior Predictive Distributions     

Caley K. Gasch  Snehalata V. Huzurbazar  Abbey F. Wick  Peter D. Stahl 《Land Degradation \u0026amp; Development》2016,27(3):521-531

We examined the interacting effects of drastic disturbance and re‐vegetation communities on the development of soil properties over time. We compared soil characteristics from an undisturbed reference site with reclaimed mine sites that differed by vegetation type and time since reclamation: Three sites were seeded solely with crested wheatgrass (Agropyron cristatum) (11, 16, and 29 years old), and two were seeded with native cool‐season grass mixes (14 and 26 years old). We sampled soil at two depths (0–5 and 5–15 cm) for soil macroaggregate and microaggregate weights, aggregate carbon to nitrogen (C : N) ratios, and microbial abundance. We employed a Bayesian bivariate model to account for potential correlations in soil properties across depths and compared soil properties across sites using posterior predictive distributions. We found that all reclaimed soils, regardless of vegetation type, had total aggregate weights that were similar to the undisturbed reference soil but had a larger proportion of macroaggregates than the reference soil. Aggregate C : N ratios were similar between the undisturbed reference and crested wheatgrass soils, while the reclaimed native cool‐season grass soils had lower C : N ratios in the top 5 cm. Total microbial abundance in soils seeded with crested wheatgrass was an order of magnitude lower than that in soils occupied by native species (both reclaimed and undisturbed). The presence of crested wheatgrass on the reclaimed sites alone did not differentiate all soil properties across our reclamation sites, but seeding this single, aggressive species may have contributed to maintaining different belowground characteristics on reclaimed soils. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献