scholarly journals Carbon Stock and Respiration of Rhizosphere Soils of Sal (Shorea Robusta Roxb. Ex. Gaertn. F.) In Relation To Some Environmental Variables of Different Sal Forest Stands of Bangladesh

2021 ◽  
Vol 50 (3) ◽  
pp. 685-693
Author(s):  
Maliha Jerin Propa ◽  
Md Imran Hossain ◽  
Ashfaque Ahmed

Effects of some environmental variables (moisture, temperature, pH) on the carbon stock and respiration in the rhizosphere soil of Sal (Shorea robusta Roxb. ex. Gaertn. f.) of 11 different Sal forest stands situated in Cumilla, Gazipur, Sherpur, Modhupur, Dinajpur and Rangpur of Bangladesh were assessed. Soil samples were collected from two layers (upper layer, 0 - 15 cm and lower layer, 15–30 cm depth). During February 2019, samples were collected from Kotbari and Rajeshpur of Cumilla and during June 2019, samples were collected from the rest of the stands. The values of different variables showed fluctuations, e.g. moisture content (11.87 - 38.78%), pH (4.73 to 6.03), conductivity (63.13 - 248.83 μS/cm), soil organic carbon (135.43 - 1263.53 ton/ha) and respiration (75.95 - 91.8 mg CO2/g soil) respectively. Rates of respiration increased where pH remained 4 to 6 and the temperature 20 to 34ºC. Rate of respiration also increased when the amount of moisture content and carbon stock decreased. This research will help to understand the role of environmental factors on the variability of soil C dynamics in the natural Sal forest areas of Bangladesh. Bangladesh J. Bot. 50(3): 685-693, 2021 (September) 

2018 ◽  
Author(s):  
Enzai Du

AbstractBased on results of a 26-year soil warming experiment (soil temperature being elevated by 5 °C) in a Harvard hardwood forest, Melillo et al. demonstrated a four-phase pattern of long-term warming effect on soil respiration, while the mechanisms were not fully elucidated because they neglected the indirect effect due to warming-induced soil drying. By showing a significant correlation between precipitation anomaly and inter-annual variation of warming effect on soil respiration, we suggest a nonnegligible role of warming-induced soil drying in regulating the long-term warming effect on soil respiration. Our analysis recommends further efforts to consider both the direct and indirect (i.e., warming-induced soil drying) warming effects to gain more in-depth understanding of the long-term soil C dynamics.


2021 ◽  
Vol 2 (3) ◽  
pp. 204-212
Author(s):  
Supuspa Regmi ◽  
Krishna Prasad Dahal ◽  
Garima Sharma ◽  
Siddhartha Regmi ◽  
Mahamad Sayab Miya

The study was conducted to find the net carbon stock in the Sal (Shorea robusta) forest in Bagdaila Chisapani community forest of Dang district, Nepal. The inventory was done by a stratified sampling technique with 0.5% sampling intensity taking into account the woody plants with ≥ 5cm DBH. A total of 49 sample plots of radius 8.94m and 5.64 were established to measure tree biomass and sapling biomass respectively in the forest. The mean above-ground carbon (AGC) was 160.4 t ha-1 and the mean below-ground carbon (BGC) was 24.1t ha-1. The mean total carbon stock in the study area was estimated to be 99.02 t ha-1; of which maximum carbon stock of 143.51 t ha-1 was found in block number 5. Sal was the major tree species in the CF. The biomass and carbon content in this forest is found quite low as compared to other studies in the Sal forest and other tropical forests which were due to the presence of tree stands of less diameter and height. This study would be helpful in the long-term management of forests, planning, and research purposes. The data from this study could also be taken as a reference document for the participation of community forests in carbon accounting under the REDD+ scheme in Nepal.


Our Nature ◽  
2017 ◽  
Vol 14 (1) ◽  
pp. 30-38 ◽  
Author(s):  
Krishna Prasad Bhattarai ◽  
Tej Narayan Mandal

Physico-chemical properties of forest soil depends on a variety of natural factors, the most important are variation in altitude, vegetation cover and microbial activities. The present study was conducted to understand the effect of variation in altitude in the soil characteristics in Tarai Sal forest (TSF) and Hill Sal forest (HSF), of eastern Nepal. Soil samples were collected from thirty plots randomly in each forest from 0- 15cm and 15-30cm depths in May 2012. Both forests had sandy loam type of soil texture. However, the percentage composition of soil particles varies within the forest sites. Soil moisture was higher in TSF. It was maximum in the rainy season in both forests. Water holding capacity was slightly higher in TSF. Bulk density was higher in TSF and it increased with soil depth in both forests. The pH value was slightly higher in HSF than TSF however, the value increased in lower soil depth in both forest stands. In the upper soil layer (0-15cm) soil organic carbon (SOC) was higher in HSF (2.09%) than TSF (1.6%). Similarly, total nitrogen (TN) was also higher in HSF (0.173%) than in TSF (0.129%) while total phosphorus (TP) was more or less same in both forest stands. The potassium (K) a soil extractable nutrient also showed higher value in HSF (312.13 µg g-1) than TSF (238.47 µg g-1). The values of SOC, TN, TP and K decreased in lower depth (15-30cm) in both forest stands. In conclusion, variation in altitude causes difference in the microclimatic condition which resulted into the alternation in soil characteristics. This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. 


Author(s):  
Akash . ◽  
M. Zakir ◽  
Navneet . ◽  
B. S. Bhandari

Sal (Shorea robusta) forest is found in an extensive array of conditions in Western Himalaya. It has been heavily used for commercial purposes. Thus, we did a study to gather the information on sal forests occupying a broad range of the Rajaji Tiger Reserve which spans across an extensive range in the Western Himalaya. We tested the species diversity, soil nutrients status, and regeneration potential of the Sal forest. Vegetation was sampled in 10 transects zone of 20×20 m2 plots covering an area of 10.0 ha area. Trees, saplings, seedlings, shrubs, and herbs were sampled along the transects in the Chilla forest division of the tiger reserve. Samplings were done every 200 m along the transect with the help of the Nested quadrat method. Altogether 64 species were recorded: 24 trees, 12 shrubs, and 28 herbs. Environmental variables like pH, organic carbon, total nitrogen, available potassium, available phosphorous, and soil texture were also recorded to observe the effects of these environmental variables into diversity attributes. The Shannon Weiner index for trees was 1.350, for saplings 1.774, for seedlings 1.679. For shrub species, it was1.96. The Shannon Weiner index for herbaceous species in the rainy season was 2.8, in winter it was 2.36 whereas in summer it was 2.46. We concluded that the management of sal has enhanced the diversity and soil nutrients dynamics in the study area. Sal diversity also has enhanced the growth of co-dominant species like Mallotus philippensis, Aegle marmelos, Listea chinensis, Naringi crenulata, Ehretia laevis, Cassia fistula, etc. in the study area. Although we did not find any seedlings of the sal during the present study, the regeneration potential of sal forest increasing with a greater number of associated species provide a favorable environment for sal species.


Author(s):  
Rami Benkreif ◽  
Fatima Zohra Brahmia ◽  
Csilla Csiha

AbstractSurface tension of solid wood surfaces affects the wettability and thus the adhesion of various adhesives and wood coatings. By measuring the contact angle of the wood, the surface tension can be calculated based on the Young-Dupré equation. Several publications have reported on contact angle measured with different test liquids, under different conditions. Results can only be compared if the test conditions are similar. While the roles of the drop volume, image shooting time etc., are widely recognized, the role of the wood surface moisture content (MC) is not evaluated in detail. In this study, the effect of wood moisture content on contact angle values, measured with distilled water and diiodomethane, on sanded birch (Betula pendula) surfaces was investigated, in order to find the relationship between them. With increasing MC from approximately 6% to 30%, increasing contact angle (decreasing surface tension) values were measured according to a logarithmic function. The function makes possible the calculation of contact angles that correspond to different MCs.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anastasia Ricci ◽  
Sara Orazi ◽  
Federica Biancucci ◽  
Mauro Magnani ◽  
Michele Menotta

AbstractAtaxia telangiectasia (AT) is a rare genetic neurodegenerative disease. To date, there is no available cure for the illness, but the use of glucocorticoids has been shown to alleviate the neurological symptoms associated with AT. While studying the effects of dexamethasone (dex) in AT fibroblasts, by chance we observed that the nucleoplasmic Lamin A/C was affected by the drug. In addition to the structural roles of A-type lamins, Lamin A/C has been shown to play a role in the regulation of gene expression and cell cycle progression, and alterations in the LMNA gene is cause of human diseases called laminopathies. Dex was found to improve the nucleoplasmic accumulation of soluble Lamin A/C and was capable of managing the large chromatin Lamin A/C scaffolds contained complex, thus regulating epigenetics in treated cells. In addition, dex modified the interactions of Lamin A/C with its direct partners lamin associated polypeptide (LAP) 2a, Retinoblastoma 1 (pRB) and E2F Transcription Factor 1 (E2F1), regulating local gene expression dependent on E2F1. These effects were differentially observed in both AT and wild type (WT) cells. To our knowledge, this is the first reported evidence of the role of dex in Lamin A/C dynamics in AT cells, and may represent a new area of research regarding the effects of glucocorticoids on AT. Moreover, future investigations could also be extended to healthy subjects or to other pathologies such as laminopathies since glucocorticoids may have other important effects in these contexts as well.


2022 ◽  
Vol 503 ◽  
pp. 119789
Author(s):  
Alex Josélio Pires Coelho ◽  
Pedro Manuel Villa ◽  
Fabio Antônio Ribeiro Matos ◽  
Gustavo Heringer ◽  
Marcelo Leandro Bueno ◽  
...  

2017 ◽  
Vol 40 (1) ◽  
pp. 1-8
Author(s):  
Bhawna Adhikari ◽  
◽  
Bhawana Kapkoti ◽  
Neelu Lodhiyal ◽  
L.S. Lodhiyal ◽  
...  

Present study was carried out to assess the structure and regeneration of Sal forests in Shiwalik region of Kumaun Himalaya. Vegetation analysis and tree canopy density was determined by using quadrat and densitometer, respectively. Density of seedlings, saplings and trees was 490-14067, 37-1233, and 273-863 ind.ha-1 respectively. The basal area was 0.12-5.44 m2 ha-1 reported for saplings and 25.4-77.6 m2 ha-1 for trees. Regeneration of Sal was found good in Sal mixed dense forest followed by Sal open forest and Sal dense forest, respectively. Regeneration of Sal was assisted by the presence of associated tree species as well as the sufficient sunlight availability on ground due to adequate opening of canopy trees in Sal forest. Thus it is concluded that the density of tree canopy, sunlight availability and also associated tree species impacted the regeneration of Sal in the region.


2015 ◽  
Vol 87 (3) ◽  
pp. 1717-1726 ◽  
Author(s):  
JULIANA WOJCIECHOWSKI ◽  
ANDRÉ A. PADIAL

One of the main goals of monitoring cyanobacteria blooms in aquatic environments is to reveal the relationship between cyanobacterial abundance and environmental variables. Studies typically correlate data that were simultaneously sampled. However, samplings occur sparsely over time and may not reveal the short-term responses of cyanobacterial abundance to environmental changes. In this study, we tested the hypothesis that stronger cyanobacteria x environment relationships in monitoring are found when the temporal variability of sampling points is incorporated in the statistical analyses. To this end, we investigated relationships between cyanobacteria and seven environmental variables that were sampled twice yearly for three years across 11 reservoirs, and data from an intensive monitoring in one of these reservoirs. Poor correlations were obtained when correlating data simultaneously sampled. In fact, the 'highly recurrent' role of phosphorus in cyanobacteria blooms is not properly observed in all sampling periods. On the other hand, the strongest correlation values for the total phosphorus x cyanobacteria relationship were observed when we used the variation of sampling points. We have also shown that environment variables better explain cyanobacteria when a time lag is considered. We conclude that, in cyanobacteria monitoring, the best approach to reveal determinants of cyanobacteria blooms is to consider environmental variability.


2008 ◽  
Author(s):  
Carlos Gustavo Tornquist ◽  
Joao Mielnickzuk ◽  
Philip Walter Gassman

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