BIOECOLOGICAL BASES OF INTERMEDIATE USE LOGGING IN NUT-PRODUCING AREAS OF CEDAR FORESTS

An increase in the production of scarce pine nuts provides for the creation of a reliable base of walnut harvesting in walnut-producing zones. A significant part of them (10.6 million hectares) does not correspond to the intended purpose and is used irrationally in the absence of documents regulating economic activity. The basis of the base being created can be cedar forest gardens of the near-settlement type, formed by intensive intermediate felling. They should contribute to the formation of the maximum volume of the female generative layer - the basis of the crop - by the age of the highest nut productivity. Bioecological features of the formation of the female generative layer depending on the lighting conditions and the age of the trees are described. It forms on the illuminated part of the crown, closer to the top, and its volume depends on the closeness and age of the trees. Female sexualization is characteristic of shoots of younger orders of branching and younger age. Older shoots and branching orders are characterized by male sexualization. After complete lightening, the female generative layer grows upward, and its volume increases. With moderate lightening, simultaneously with upward growth, branches in the lower part of the fruiting layer are reborn, and its volume changes slightly. The female generative layer is not formed in the middle and lower parts of the trunk after clarification. In clean closed 120-year-old cedar forests, narrow, 70-80% non-fruiting crowns with a highly raised fruiting layer are formed in trees. Its volume is 60-70% less than that of freely growing cedars. Clarification of trees at this age, with a decrease in the recommended fullness to 0.5, is ineffective. The female generative tier will no longer reach the biologically possible potential: in the middle and lower parts of the trunk, the branches of female sexualization are replaced by male and growth shoots. The upward expansion of the female generative layer will provide only a limited reproductive effect. Cutting operations 40 years earlier, i.e. at 80 years old, will increase the potential volume of the fruiting layer to 42-50%, and nut productivity by almost 1.5 times.rease the potential volume of the fruiting layer to 42-50%, and nut productivity by almost 1.5 times.

Effects of AgNPs on the Snail Biomphalaria glabrata: Survival, Reproduction and Silver Accumulation

Silver nanoparticles (AgNPs) are used intensively in medical and industrial applications. Environmental concerns have arisen from the potential release of this material into aquatic ecosystems. The aims of this research were to evaluate the potential accumulation of silver in the whole body of organisms and analyze the effects of AgNPs on the survival and reproduction of the snail Biomphalaria glabrata. Results show slow acute toxicity with a 10-day LC50 of 18.57 mg/L and an effective decrease in the eggs and egg clutches per organism exposed to tested concentrations. Based on these data, the No Observed Effect Concentration (NOEC) observed was <1 mg/L for snail reproduction. For silver accumulation, we observed that uptake was faster than elimination, which was very slow and still incomplete 35 days after the end of the experiment. However, the observed accumulation was not connected with a concentration/response relationship, since the amount of silver was not equivalent to a higher reproductive effect. The data observed show that AgNPs are toxic to B. glabrata, and suggest that the snail has internal mechanisms to combat the presence of Ag in its body, ensuring survival and reduced reproduction and showing that the species seems to be a potential indicator for Ag presence in contaminated aquatic ecosystems.

Assessment of knowledge and practice on plastics among the professional course students of Annamalai University, Tamil Nadu

Background: The use of plastics made life easy in day to day life. However, the disposal of it remains a public health problem worldwide. Plastic waste are major cause of environment pollution becomes carcinogenic to human, birth defects, impaired immunity, endocrine disruption, development and reproductive effect. Raising the awareness of the different stake holders is suggested by United Nations Environment Programme. Assessing the knowledge and practice of the student community, especially of the professional courses, in this regard is considered as a vital one.Methods: A total of 563 students of professional courses were included in the study. Their knowledge in terms general aspects, ill effects, reuse and practice in terms of usage and disposal were assessed with a questionnaire.Results: 46% of the students found having good knowledge. Only 27.6% were found to have good practice. Though the students have good knowledge on ill effects of plastics, their practice in terms of disposal was less. Significant variations were observed among the students of different courses.Conclusions: Addressing the gap between knowledge and practice in terms of designing messages for proper disposal and avoiding usage of single use plastics at individual and collective level is required.