Search

Water induced soil erosion has always been a matter of concern in watersheds as they increase the soil vulnerability towards erosion. If unchecked, the eroded material reduces the capability of the river to carry the adequate amount of water and increase the amount of sediments in the watershed area. Determining vulnerability of soil to erosion plays a key role in identifying the extent of fragility and helps in making appropriate plans for conservation. Among various methods present to assess soil erosion vulnerability, there is a need to understand the frequently used methods so far and its advancement with time. Various models have been used in past two decades (1991-2019) and the Revised Universal Soil Loss Equation (RUSLE) is the most used model because of its quantitative ability to estimate the average annual soil loss due to erosion in a watershed and its compatibility with the GIS interface. Different approaches like MCDM, SWAT etc. are being utilised to study soil erosion vulnerability of watersheds. This review showed that the frequently used MCDM method is a Compound Factor (CF) method and that RUSLE is a most used quantitative approach. The review identifies 14 different methods which includes 4 methods which provide quantitative estimation while the other 10 methods are used for qualitative assessment of soil erosion vulnerability. Being the most adopted approach, various modifications of different factors of RUSLE introduced by researchers have made it more efficient with time. This review identifies the trend in advancement of various approaches and methods to study soil erosion vulnerability of watersheds around the world and also how various studies are distributed in the Himalayan and non-Himalayan region. The review also provides an understanding of the status of various current approaches to study soil erosion in a watershed and lists the improvements adopted in the frequently used approaches during 1991 and 2019.

Wetlands are very important ecosystems from the ecological, productivity and conservation perspective. Economic valuation of ecosystem services provided by wetlandsquantifies the various benefits derived from wetlands and puts a value on their conservation. One such wetland of importance is the Renuka wetland, which is a natural wetland located in the Western Himalayas, in the State of Himachal Pradesh of India. The article aims to assess and evaluate the wetland for its water purification service. The study is based on multisource data and conventional evaluation method. The results show that the average depth of the Renuka wetland is 6.01 m and average volume was determined as 1072530.176 m3. The economic value of water purification service for Renuka wetland is estimated to be INR 31.9 million(0.44 million USD) thus identifying the Renuka wetland as a significant healthy ecosystem. The water purification value itself advocates its proper management and conservation.

Ranked Set Sampling (RSS) is a sampling strategy which is advantageous when measurement of sampling units is very difficult but when small sets of units can be ranked according to other methods that do not require actual measurements. The units corresponding to each rank are used in RSS and RSS performs better than simple random sampling (SRS) when estimating the population mean of forestry or environmental parameters (say, below ground biomass). A new RSS procedure based on alternate order statistics for estimating the population mean (ARSS) is suggested in this paper. ARSS measures only the first, third, fifth and so on units so that the information on remaining order statistics is represented by their respective neighboring order statistics. The bias correction term in the proposed estimator is included and calculated for some skewed and symmetric (both mound and U shaped) distributions. The estimators under ARSS are then compared to the estimators based on balanced RSS and Neyman's optimal unbalanced RSS allocations. Based on the computed Relative Precisions (RPs), estimators based on ARSS are recommended for even set sizes of skewed distributions and odd set sizes of mound shaped symmetric distributions. RPs of these distributions are uniformly better than the other two methods (balanced and Neyman's RSS). To demonstrate the performance of the different estimators, an example from forestry that estimates total biomass of three tree species is presented. The proposed method is efficient in forestry and environmental applications. [ABSTRACT FROM AUTHOR]

Rising atmospheric carbon dioxide (CO2) and temperature alter gene-expression arrays commensurate with physio-morphological changes, resulting in issues of adaptation, growth patterns, and productivity of terrestrial vegetation. An experiment was conducted to investigate the adaptive response of Populus deltoides clone G48 to the combined effect of elevated CO2 and temperature inside open-top chambers. The elevated CO2 and temperature acted as environmental cues to help express upregulated/downregulated genes involved in important metabolic pathways. As a result, P. deltoides exposed to the elevated CO2 and temperature developed adaptation to undo the effect by enhancing gaseous exchange, transpiration, and carbon assimilation and partitioning as observed on 180 days after treatment. The elevated conditions significantly enhanced stomatal density and size on adaxial/abaxial leaf surfaces, chlorophyll b that augmented photosynthesis, stomatal conductance, transpiration, and internal CO2, but decreased instantaneous and intrinsic water-use efficiency. These stimulated biomass accumulation in root, stem, and leaves. Hence, the elevated conditions of CO2 and temperature operate at the gene-expression level that acts pleiotropically for reinforcement of photosynthetic apparatus, morphological amendment for accelerated gaseous exchange, and finally growth and biomass improvement, supporting adaptive plasticity of clonal planting stock of the species to future climatic change and global warming. [ABSTRACT FROM AUTHOR]

In the presented study we examine how the temporal variations of eulophid species richness in differed in three land-use patterns in five seasons over a span of three years in seven locations in Doon Valley, India In most of the locations highest values for temporal richness of eulophids were observed in summer season in most of the locations throughout study period and lowest values were observed in spring and post-monsoon season. The results of this study have important implications for the assessment of biodiversity status of family Eulophidae in different habitats. [ABSTRACT FROM AUTHOR]

Winter cherry or Ashwagandha (Withania somnifera) is an important medicinal plant used in traditional and herbal medicine system. Yet, there is no information available on response of this plant to changing climatic conditions particularly elevated atmospheric CO2 concentrations. Therefore, we conducted an experiment to examine the effect of elevated CO2 concentrations (ECs) on Withania somnifera. The variations in traits of physiological adaptation, net primary productivity, carbon partitioning, morphology, and biomass in response to elevated CO2 concentrations (ambient, 600 and 800 µmol mol−1) during one growth cycle were investigated within the open top chamber (OTC) facility in the foothill of the Himalayas, Dehardun, India. ECs significantly increased photosynthetic rate, transpiration rate, stomatal conductance, water use efficiency, soil respiration, net primary productivity and the carbon content of plant tissues (leaf, stem, and root), and soil carbon. Furthermore, ECs significantly enhanced biomass production (root and shoot), although declined night leaf respiration. Overall, it was summarized that photosynthesis, stomatal conductance, water use efficiency, leaf, and soil carbon and biomass increased under ECs rendering the physiological adaptation to the plant. Increased net primary productivity might facilitate mitigation effects by sequestering elevated levels of carbon dioxide. We advocate further studies to investigate the effects of ECs on the accumulation of secondary metabolites and health-promoting substances of this as well as other medicinal plants. [ABSTRACT FROM AUTHOR]