PG Thesis
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Item Growth dynamics and physiological response of selected forestry species to CO2 enriched atmosphere(Academy of Climate Change Education and Research,Vellanikkara, 2019) Anusha, R M; Nameer, P OTerminalia arjtma, Terminalia bellirica and Terminalia chebula are important medicinal plants and part of Triphala, there is less study about the adaptation and mitigation of these species to elevated CO2. This study is helpful to understand about the adaptive and miligative and biochemical efficiency of these plants. Under elevated these three species are showed a belter response in elevated CO2 SOOppm over ambient 400ppm. The plant height, leaf length and width, stem diameter, number leaves and branches, root length, are higher in elevated SOOppm CO2 over ambient 400ppm as well as the biochemical properties like total chlorophyll and carotenoids, ascorbic acid, protein, proline, total sugar are increased dramatically at SOOppm over 400ppm. The photos>Tithetic rate was higher in elevated CO:in all seasons (winter, spring, and summer), stomatal conductance was higher in SOOppm spring and lower at summer. The intercellular CO2 concentration was higher in plants grown in SOOppm T.chebula in winter in the summer season. Transpiration rate was higher in winter and reduced over ambient in summer. Night respiration is less in T.arjuna compared to ambient, and there is a fluctuation concerning seasonality and species. Carbon sequestration, carbon partitioning, carbon mitigation and carbon stocks are high in elevated CO2 growing plants except for T.bellirica. Organic carbon was higher in elevated CO2 than ambient. Potassium, phosphorous and total nitrogen they with species and change in concentration according to elevated CO2. The plants grown in elevated CO2 are healthier than ambient condition and increases the health-promoting characters. These species are more adaptive and show mitigation efficiency and good biochemical efficiency. In future more studies needed to know about the response of plants towards elevated CO2.Item Quantify the temporal carbon, water and energy fluxes in selected land use systems in Himalayas(Academy of Climate Change Education and Research,Vellanikkara, 2019) Arya, M S; Nameer, P OAn investigation entitled “Quantify the temporal carbon, water and energy fluxes in selected land use system in Himalayas” was conducted at Forest Research Institute (FRI), Dehradun, during 2018 December to May 2019. The experiment was conducted in two seasons winter (December-February) and summer (March-May) with four land use i.e.; mixed forest, pine forest, grassland and bamboo forest. Soil physical properties are also considered at the depth of 015cm and at 15-30cm. The study aimed to give an insight of carbon, water and energy flux variations along micrometeorological observations. The results revealed that during summer season (air temperature increased) all the respective observed fluxes significantly rose, among selected land use. Grassland showed high flux release from the system to the atmosphere. While mixed forest, soil experienced gradual rise in flux exchange, but pine forest system stores greenhouse gases like carbon dioxide in a long time period in a safe manner. Apart from flux, soil temperature and soil moisture were also examined and obtained data showed a decrease in moisture and increase in soil temperature with air temperature rise except leaf shedding months. As the study show that different land use had evident impact on variability in climatic conditions and hence more than considering the green covers, specific land use flux exchange monitoring is required for all terrestrial land use.Item Carbon sequestration and crop weather relations in long term fertilizer experiments(Academy of Climete Change Education and Research, Vellanikkara, 2018) Sudhamani, P; Thulasi, VItem Forage yield, soil fertility and carbon dynamics of calliandra (Calliandra calothyrsus meissn,) in coconut plantation(Departament of Silviculture and Agroforestry , College of Forestry, Vellanikkara, 2017) Jilna Joy; Asha K RajA study entitled “Performance of calliandra (Calliandra calothyrsus Meissn.) under diverse management regimes in a coconut based hedge row fodder production system” was carried out at Instructional Farm, College of Horticulture, Vellanikkara during 2014-2015. The main objective of the study was to assess the influence of management practices like tree density, pruning height and pruning frequency on initial growth, forage yield and nutritional qualities of calliandra intercropped in coconut gardens under humid tropical conditions of Kerala. The treatments consisted of three levels of plant density (27,777; 22,222 and 17,777 plants ha-1), three levels of pruning frequency (8, 12 and 16 weeks interval) and two levels of pruning height (0.5m and 1m) in all possible combinations laid out under factorial randomized block design with three replications. The results revealed that various management practices had a profound influence on the forage yield and quality aspects of calliandra when grown as an intercrop in coconut garden. Comparing plant densities, highest density stand (27,777 plants ha-1) yielded 55 percent more forage (11.73Mg ha-1yr-1, dry basis) than the lowest density (17,777 plants ha-1), with higher foliage fraction. Quality parameters of forage like crude protein, ash, dry matter, phosphorus and potassium content increased and crude fibre content decreased at higher densities indicating closer spacing for production of tender nutritive fodder. Pruning at the prolonged interval of 16 weeks yielded more total forage, but the majority of the fodder comprised of stem fraction as indicated by the poor leaf-stem ratio. Leaf –stem ratio of fodder harvested at 8 and 12 weeks showed an increment of 125 percent over that of the 16 weeks interval, indicating more foliage production than stem fractions when harvested at shorter intervals. Pruning frequencies also had profound influence on nutritive value of the forage. Harvesting at shortest interval of 8 weeks and 12 weeks yielded fodder with maximum crude protein, phosphorus and potassium content when compared to 16 weeks. Ash and dry matter content in 99 fodder was significantly higher at the longest interval of 16 weeks. Crude fibre content of forage increased sharply from 28.33 to 49.98 percent by prolonging the harvest interval from 8 to 16 weeks thereby adversely affecting the palatability of the forage. Pruning height showed more prominent influence on forage yield of calliandra than the nutritive parameters. Dry fodder yield increased from 8.11 to 10.81 Mg ha-1yr-1 with increasing pruning height from 0.5 to 1m, with a higher leaf-stem ratio for taller stocks. Similarly there was a significant improvement in CP yield from taller stocks (1.67 Mgha-1 )when compared to shorter ones (1.23 Mgha-1) The interaction effects of plant density, pruning height and pruning frequency had no significant effect on yield and quality parameters of callianrda. The highest yielding combination (13.39 Mg ha-1dry basis) was found to be D1H2F2 (27,777 plants ha-1 + pruning height 1 m + pruning interval 12 weeks ) with higher foliage fraction and better nutritive parameters, compared to all other management levels, which were inferior either in forage yield or nutritive value or palatability of forage. On the whole, the study revealed that forage yield and quality of young stands of calliandra underneath coconut garden could be optimized at the cheapest level by adopting a tree density of 27,777plants ha-1, pruning height of 1m and pruning interval of 12 weeks. Moreover, based on the growth and yield performance and quality aspects, it is found that calliandra is a promising fodder tree, which can be successfully integrated with the existing coconut gardens of Kerala. Establishment and proper management of calliandra in coconut garden at appropriate management levels thus offers a cheap source of quality forage to Kerala farmers against the highly expensive concentrate feeds.Item Sequestration of carbon as influenced by nutrient management practices under long term fertilizer experiments(Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 2017) Sumayya Sulaiman; Thulasi, VItem Assessment of soil carbon pools in acid sulphate soils of Kuttanad(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2017) Dhanya, K R; Gladis, RItem Carbon dynamics in teak planted laterite soils of Kerala(Academy of Climate Change Education and Research Vellanikkara, 2016) Binsiya, T K; Kurien, E KGlobal warming due to increased concentration of greenhouse gases (GHGs) is one of the important concerns of mankind today. The global soils store about 2500 Gt of carbon which is approximately 3.3 times the atmospheric carbon pool (760 Gt) and 4.5 times than that of the biotic pool (560 Gt) . Kerala has a rich forest cover of which 10 per cent is occupied by forest plantations. Among the plantation species, teak occupies the most prominent position both in acceptance and coverage. However, continuous teak rotation affects the quantity and stability. Hence the present study was taken up to assess the changes in carbon fractions and carbon stability under continuous teak rotations in midland laterites of Kerala. Soils were collected to a depth of 1 m with a depth interval of 20 cm in a chronosequence from 16 plantations at Nilambur, Kerala. Basic soil parameters such as pH, electrical conductivity, bulk density, mean weight diameter, texture, available nitrogen, potassium, phosphorus, iron, calcium, copper, manganese, magnesium, zinc and boron content were analyzed using standard protocols. The carbon fractions were assessed with respect to active, slow, passive and total carbon in soil as well as macro and micro aggregates. The study also assessed the rate kinetics, thermal stability and cumulative CO2 efflux of soil carbon decomposition in these soils by batch incubation experiments at different temperatures. The results showed a reduction of soil basic characters below critical levels with continuous teak rotations. In general, the carbon content was found to decrease depth wise with rotation. However, in plantations without felling organic carbon was found distributed equally in all the layers which may be due to the unhindered transportation and translocation of humic materials with time in these plantations. The carbon stocks in the plantations do not have significant difference between the age groups in their carbon storage capacity. This indicated that carbon losses from the teak plantation are readily replenished and the changes may be expected only in the quality of the stored carbon. Macroaggregates were found to store more organic carbon than the microaggregates. The correlation between carbon and aggregate stability was found to decrease with rotation. Plantation that was grown continuously showed a relatively lower proportion of active carbon than slow and passive carbon fractions. This indicated that even though there was a total carbon increase in plantations under continuous growth, the entire carbon may not be in a labile form to support ecosystem services. Thermal stability studies showed that microaggregates provided better protection to organic carbon by a greater complex mechanism compared to macroaggregates. With temperature, there was an increased conversion of active carbon to passive forms and this conversion could lead to higher carbondioxide evolution once the threshold energy levels were attained. Carbon dioxide efflux studies confirmed these results as higher cumulative CO2 evolution was obtained at 40°C than 25°C in all soils. Further, cumulative CO2 evolution from continuous plantation without felling didn‘t get affected with temperature indicating a dynamic equilibrium with atmosphere. The present study concluded that continuous teak rotation destabilizes carbon in soil and shows the potential to revert to a carbon source than sink if not managed sustainably.Item Carbon dynamics of acid saline pokkali soil under long term fertiliser application in rice(Academy of Climate Change Education and Research Vellanikkara, 2016) Sharon Mathew; Sreelatha, A KThe amount of carbon in the atmosphere has increased by 30 per cent. The rising temperatures and carbon dioxide concentration and uncertainty in rainfall associated with climate change may have direct relationship with increased levels of carbon dioxide. One proposed method to reduce atmospheric carbon dioxide is to increase the global storage of carbon in soils with an added benefit in simultaneous enhancement in agricultural production. Soil organic carbon (SOC) is one of the main carbon reservoirs in the terrestrial ecosystem. It is important to study SOC dynamics and effects of organic carbon amendments in paddy fields and saline soils because of their vast expansion Objectives of the study were to estimate the soil organic carbon (C) status in acid saline soil and to assess the influence of long term fertilizer applications on soil carbon dynamics. Samples were collected from the experimental plot laid out in randomized block design with 10 treatments, each replicated four times with pokkali rice variety Vytilla 4 at RRS Vytilla, Kerala. The study revealed the baseline soil characteristics especially the soil carbon and its counterparts. Vertical distribution of SOC showed the storage profile of carbon and in cultivated sites a topsoil carbon sink (mostly labile carbon) is identified owing to increased fertiliser inputs whereas a potential subsoil sink (non labile carbon) is identified vertically downwards. However, the high content of non labile carbon in the subsurface showed the ability of Pokkali soil for carbon sequestrations. The labile carbon present in the surface soil resulted in the availability of nutrients to the plants which was evident from the high nutrient status of the control plot .all carbon fractions in the present study indicates the ability of Pokkali soils to sequester carbon. Therefore, the Pokkali ecosystem has to be maintained as such to mitigate the ill effects of global warming in the present climate change scenario.Item Comparative analysis of carbon and nutrient pools in soils of selected woody ecosystems of central Kerala(Academy of Climate Change Education and Research Vellanikkara, 2016) Veena Prasad; Kunhamu, T KPresent study entitled “Comparative analysis of carbon and nutrient stocks in soils of selected woody ecosystems of central Kerala, India” was carried out at the Academy of Climate Change Education and Research, Kerala Agricultural University, Vellanikkara, Thrissur during 2015-2016. The study showed that the carbon and nutrient stocks were significantly influenced by the treatments. Soil organic carbon is significantly different in each plantation and was significantly higher than corresponding contiguous treeless soils (p < 0.005). Also there was significant reduction in depth. Carbon stock was higher for mahogany plantation (116.01 Mg C ha-1) followed by homestead (105.41 Mg C ha-1) and teak (103Mg C ha-1). Lower carbon stock was found for mango (76.08Mg C ha-1) and acacia (75.19 Mg C ha-1). Carbon stock for each plantation was significantly higher than contiguous open plot. Similarly highest nitrogen and potassium stock was recorded for mahogany plantation (53.61 Mg N ha-1 and 1030.6 Kg K ha-1) which were significantly different from contiguous open plot. Nitrogen stocks were lower for acacia (26.77 Mg N ha-1) and mango (26.77 Mg N ha-1) but are significantly higher from treeless condition. Nitrogen stock in homestead (30.17 Mg N ha-1) and teak (38.29 Mg N ha-1) was higher than acacia and mango but lower than mahogany. Available phosphorous was lower in all woody ecosystems other than homestead (154.56 Kg P ha-1) with significant reduction across depth. The results of the present study revealed that soil organic and nutrient stock varied significantly with woody ecosystems and slow growing species as well as multi-strata ecosystem enrich soil with carbon and nutrient better than fast growing species like acacia. Also is significantly higher than treeless condition. Enhancing tree cover is thus an efficient method to mitigate global warming. Hence choice of the species and their management conditions are important considerations while designing plantation forestry programs particularly when their carbon sequestration and greenhouse gas mitigation potential are considered.Item Carbon storage potential of intensive silvopasture systems in humid tropics of kerala(Academy of Climate Change Education and Research, Vellanikkara, 2016) Varsha, K M; Asha K Raj