Journal of Research and Development

Centre of Research for Development

University of Kashmir

Print ISSN: 0972 - 5407 Online ISSN: 0972 - 5407

The paper reports about the impact of Conyza canadensis on species that co-occurs with it in invaded and uninvaded plots at the various sites located in Kashmir Himalayas. These invaded and un-invaded plots supports diverse plant species varying in their status like native and non-native species which were at different stages of invasion, including invasive species, naturalised species, casual alien and cultivated un-escaped alien. Various ecological factors, such as disturbance and pollution have caused prominent changes in the dynamics and distribution of the native species of Kashmir Himalayas. The paper highlights the adverse impact of the invasive species on its co-occurring native species and facilitative role to non native aliens. Higher number and better performance of alien species in invaded than un-invaded plots in comparison to higher number and better performance of native species in un-invaded plots indicates invasion meltdown.

Walnut wood an important natural resource is used in high class and decorative joinery for furniture and tableware, and also in decorative construction work such as in Mosques, houses, Khanqaas, Shrines and other public and private buildings, to which it is eminently suitable due to its strength and durability at the same time relatively little is known about anatomical characteristics of its wood. For this purpose sections were cut in three different planes and also maceration was done in order to know about wood anatomical features viz. fiber length, fiber diameter, fiber wall thickness, vessel element length and vessel element diameter, growth ring.

Environmental effects of harvesting have been reported in aquatic ecosystems around the globe. An ecological monitoring study was undertaken to ascertain the impacts of this lake management practice on the structure and distribution of Periphyton community of Dal lake ecosystem. Deweeding significantly reduced periphytic diversity and density (P<0.05). Upon initiation of deweeding process, maximum number of dominant taxa got removed along with the harvested weeds, which as a result provided an opportunity for few rare taxa to thrive at such sites. Bacillariophyceae was the dominant group in all seasons. Cyanophyceae (Oscillatoria sp. and Anabaena sp.) registered slight rise after deweeding. The species of Achnanthidium, Synedra, Chlorella, Navicula, Cymbella and Fragillaria were observed to be highly prominent at deweeding sites. Due to harvesting operation, species composition and distributional pattern of this very important autotrophic community got altered. The present study concludes that there was a negative impact on periphyton community by deweeding process soon after implementation of this practice. The recovery rate of studied periphytic community was slow. In order to ascertain the full recovery of periphytic community, long term ecological monitoring (>10 years) is mandatory.

The environment is currently polluted by thousands of chemicals or xenobiotic introduced into the environment by man to meet the demands of the modern era. The pollution is continuous and alarming in flux to aquatic environment worldwide from both naturally occurring and anthropogenic sources. The polluted water may lead to the destruction of the beneficial species either directly effecting aquatic forms of life in directly through breaking the biological food chain such as fish and their habitat and behavioral pattern. The fish as a bio indicator of aquatic medium plays an important role in the monitoring of water pollution because of the sudden death of fish indicates heavy pollution and the effects of exposure to sub lethal levels can be measured in terms of biochemical, physiological and histological responses of the fishes. In the present study, the sub lethal effects of arsenic on various biochemical parameters of Channa gachua were studied. The fish was exposed to sub lethal concentration of arsenic for 20 days for chronic toxicity studies. Total protein, amino acid and acetyl cholinesterase, glycogen and lactic acid were observed. The present study showed the protein content was decreased and amino acid content was increased significantly and also Acetyl cholinesterase was increased in the liver tissue of arsenic treated fish, Channa gachua. The present study shows the level of glycogen decreased and lactic acid increased in the liver tissue of fish exposed to arsenic. These changes were concentration dependent.

Micronuclei test is a system of mutagencity testing used for determining the pollution and chemicals causing changes in DNA fragments such as micronuclei in the cytoplasm of interphase cells. Damage caused on the DNA by genotoxic pollutants is the first consequence occurring in the aquatic organisms. The aquatic environment makes up the major part of our environment and resources, therefore its safety is directly related to the safety our health, thus, it was attempted to determine whether pollution affected the erythrocytes of fish Cyprinus carpio at the level of DNA by the means of micronuclei (MN) test. The test has been used successfully as a mutagenic assay. It is simple, reliable, sensitive, and it does not depend on any karyotypic characteristics. Fish were collected from locations that display differential environmental stresses. Organisms used in the MN test were collected from Dal Lake and Mansbal Lake. According to the results of the present study, frequency of MN was found higher in fishes from Dal water compared to Mansbal Lake. In conclusion, this study indicates that the micronuclei test gives sensitive results in monitoring the pollution, and thus it might be used as standard method in regular monitoring of pollution of water bodies.