PG Thesis

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Functional trait variations and drought tolerance among teak (Tectona grandis Linn.f.) provenances
(Department of Forest Biology and Tree Improvement, College of Forestry, Vellanikkara, 2024-11-27) Muhammed Ajsal, K K; Delphy Rocha
The present study investigated, functional trait variations among six provenances of Tectona grandis L. f, in the 90 year old provenance trial plot at Aravallikavu, Nilambur consisting of Anamalai, North Burma, Nilambur, South Bombay, South Burma and Travancore provenances. In addition, genetic diversity among these six teak provenances using ISSR markers and drought tolerance of these six provenances were also studied. Functional traits such as height, GBH, crown width, and self-pruning activity of teak provenance showed significantly different variation. However, leaf thickness not showed significantly different variations among the provenances. The South Burma provenance showed highest height (28.48m), crown width (9.05m) and self-pruning activity (0.82), whereas Nilambur provenance showed highest GBH of 168.06cm. The South Burma provenance showed highest stem straightness. In addition, foliar nitrogen concentration showed significantly different variations among the provenances. South Bombay provenance showed highest leaf nitrogen concentration of (2.54%). However, both phosphorous and potassium concentration did not significantly vary among provenances. Genomic DNA from six teak provenance was extracted using the modified CTAB protocol, yielding DNA concentrations ranging from 117.3 to 284.11 ng µL-1, with OD260/280 values between 2.06 and 2.21. Amplified bands resulted in 37 observed alleles, of which 32were polymorphic, demonstrating genetic diversity, while 5 were monomorphic. The Jaccard dissimilarity coefficient between Anamalai and South Bombay was 0.43, suggesting their genetic similarity. Whereas highest dissimilarity was observed between South Bombay and South Burma with coefficient of 0.67. Morpho-physiological and biochemical responses of teak ramets to drought stress were evaluated. Based on morphological indicator (percent leaf retained), Anamalai and South Bombay provenances were classified as "moderately Tolerant," whereas South. Burma was "Susceptible". Photosynthesis varied, with South Bombay maintaining the highest rate (3.27μmol CO2 m-2 s-1) and Travancore exhibiting the lowest (1.75μmol CO2 m-2 s-1) under xvi drought. Provenance displayed diverse responses under drought for relative water content (56.61%- Travancore to 84.62%-South Bombay) and total chlorophyll content (4.94 mg g⁻¹ South Bombay to 2.84 mg g⁻¹-Travancore). Maximum proline was produced by South Bombay (9.11μg g-1). Similarly, South Bombay displayed higher peroxidase activity (8.53μmol min-1). Hierarchical cluster analysis categorized teak provenances into Susceptible (Nilambur and Travancore), Moderately Tolerant (North Burma and South Burma), and Highly Tolerant (Anamalai and South Bombay) categories. The study enhances understanding of the functional trait, genetic variations and drought tolerance of six teak provenances contributing valuable information for breeding programs and sustainable forest management. The multidisciplinary approach integrating physiological, biochemical, and genomic analyses offers a comprehensive framework for understanding and improving teak cultivation, ensuring sustainable production in the face of environmental challenges.
Foliar uptake and accumulation of nanoplastics and its effect on growth and physiology in selected tree seedlings
(Department of Forest Biology and Tree improvement, College of Forestry, Vellanikkara, 2025-04-26) Archana Abraham; Delphy Rocha; Misha Davis, A
The persistent nature of plastics, combined with inadequate waste management practices, poses a significant and escalating threat to both terrestrial and marine ecosystems worldwide. This study investigated the foliar uptake, accumulation and physiological effects of nanoplastics (NP) in seedlings of Tectona grandis, Gmelina arborea, and Macaranga peltata. Five-month-old seedlings were subjected to foliar application of NP solutions (0.1 mg L⁻¹ and 1 mg L⁻¹) for 21 days, with control plants serving as a baseline. Confocal Laser Scanning Microscopy confirmed the uptake and systemic transport of nanoplastics in leaves, stems, and roots of all species. Growth parameters, including height and collar diameter, showed significant reductions in Tectona grandis, while physiological parameters such as photosynthesis, stomatal conductance, transpiration, and chlorophyll content declined across all species, with the most pronounced effects observed at higher nanoplastic concentrations. Biochemical analyses revealed reductions in total soluble sugars, proteins, and phenolic content, particularly in Tectona grandis and Gmelina arborea, suggesting oxidative stress and metabolic disruptions. The results highlighted strong correlations between nanoplastic exposure and impaired physiological functions. These findings provide crucial insights into the species-specific responses of trees to airborne nanoplastic contamination, emphasizing the need for further research on the ecological consequences of nanoplastics in forest ecosystems. By examining these effects, the research aims to provide insights into the potential risks posed by airborne nanoplastics to plant health.
Risk assessment and habitat invasibility of Ageratine adenophora (Spreng) R.M. King & H.Rob in Pampadum Shola National park, Kerala
(Department of Forest Resource Management, College of Forestry, Vellanikkara, 2024-12-17) Nikhil, P V; Aneesh, K S
Characterization of wood physical and anatomical featurs for the development of identification keys for twenty tree species of South India
(College of Forestry, Vellanikkara, 2023-03-18) Ashline Shaji; Anoop, E V
Wood has played a vital role in the history of human civilisation. Mankind have been using it as a building material, for making furniture, paper and fuelwood since time immemorial. The demand for wood continues to increase annually, even today. The rapidly expanding global population has created consumer demand for wood and wood products. This has led to unsustainable exploitation of forests globally, paving the way for illegal logging and resultant timber adulteration (UNODC, 2020). Illegal logging and global trade of such timber accounts for 51-152 billion U.S. dollars annually (INTERPOL, 2019). Accurate identification of timbers is therefore a need of the hour. Identifying the timber is also a necessity, even to determine its general end-use. In this backdrop, the present study was conducted to characterise the physical and anatomical features of 21 timber species and to develop a dichotomous Key and an IAWA (International Association of Wood Anatomists) Key for the accurate identification of the selected species. A survey was conducted, and wood samples were collected from different parts of Kerala. The procured samples were cut to the required dimensions (1x1x1 cm3 ). Gross features were recorded, and sections were prepared using a sliding microtome (Leica SM 2000R). Permanent slides were then prepared. The photomicrography of Transverse Sections (TS), Tangential Longitudinal Sections (TLS), and Radial Longitudinal Sections (RLS) were taken using a Catymage® image analyzer using a Catcam 500E series microscope camera, mounted on a Motic BA210 trinocular microscope. Physical properties like colour, odour, lustre, texture, basic density etc. and micro anatomical properties like vessel, ray and fibre morphology were studied. All the quantifiable parameters differed significantly between the species and characteristic features were identified. Wood specific gravity differed significantly. Highest specific gravity was observed in Hopea parviflora and Cocos nucifera, while the lowest specific gravity was observed in Ceiba pentandra. All the species studied (except Cocos nucifera) were categorised as diffuse porous. Small vessels were found in Aegle marmelos and comparatively larger vessels were observed in Ceiba pentandra. Vessels were solitary and in radial multiples of 2-3 in most of the species studied, except Casuarina equisetifolia which were exclusively solitary and in Alstonia scholaris they were in radial multiples of 4-8. Maximum vessel diameter was observed for Ceiba pentandra with 258.38 µm followed by Bombax ceiba with 232.11 µm and Acrocarpus fraxinifolius with 224.34 µm. The lowest vessel diameter was recorded in Aegle marmelos (93.82 µm) and Casuarina equisetifolia (99.11 µm). mm2 Vessel frequency was found to be highest in Aegle marmelos (37 per mm2 ) followed by Bridelia retusa (24 per mm2 ) and the lowest was recorded in Acacia nilotica, Albizia odoratissima, Hopea parviflora and Lagerstroemia lanceolata with a value of 3 per . Rays were observed to be variable, with a mixture of homocellular and heterocellular rays to exclusively homocellular rays. In Aegle marmelos, Albizia odoratissima and Cassia fistula, only procumbent rays were observed. Ray frequency was analysed in the present study and it was found that the highest ray frequency was found in Casuarina equisetifolia (15 per mm) Cassia fistula (13 per mm) and Neolamarkiana cadamba (13 per mm) and the lowest was recorded in Ceiba pentandra (4 per mm), followed by Bombax ceiba (5 per mm) and Melia dubia (5 per mm). Ray height was highest in Bombax ceiba (1.25 mm), followed by Bridelia retusa (1.50 mm) and the lowest was recorded in Cassia fistula (0.21 mm ) followed by Casuarina equisetifolia (0.22 mm). Paratracheal parenchyma is an advanced character and was observed in most of the species. Angular vessel outline was observed only in Alstonia scholaris. Utilizing all the physical and anatomical information obtained from the study, a dichotomous key and an IAWA key was prepared for the selected timbers species.
Phylogenetic analysis of the endemic and threatened bat Hipposideros pomona K. Andersen, 1918 (Chiropetra: Hipposideridae) in the Western Ghats
(College of Forestry, Vellanikkara, 2023-03-02) Abhin M Sunil; Nameer, P O
Hipposideros pomona K. Andersen, 1918 is a small to medium sized insectivorous bat species endemic to the southern Western Ghats (SWG). According to IUCN, the species is endangered due to its restricted distributional. It is found mainly in thick forests of mid to high elevations of the SWG. Biogeographic barriers can act as a barrier to species dispersal, resulting in reproductive isolation and thus aiding speciation. The effect of the barriers depends on the motility of the animal. Actively moving and robust animals, such as higher vertebrates, may disperse across more minor barriers, while less mobile animals could be restricted due to the same. The 30 km wide Palghat gap in the SWG acts as a barrier to the species movement for many forest depended species, consequently acting as a barrier for gene flow, which can result in speciation as well as increase the chances of gene pool isolation. This barrier could affect the movement between subpopulations of H. pomona in the south and north of the Palghat gap. The current study was conducted in Kerala part of the SWG, on the locations where H. pomona was previously recorded. Bat sampling was carried out using harp traps of dimension 1.5m width, 2.2m height, 7.5cm between four frames and 2.5 cm between vertical monofilament fishing lines. Sixteen standard morphological measurements were taken on the bats captured in the harp trap (to the nearest 0.1mm) using a digital vernier calliper. Wing punches of 3 mm diameter were taken with a sterile biopsy punch, preserved in molecular grade ethanol, and stored in a deep freezer. DNA extraction was carried out using the standard protocol. Polymerase chain reaction performed to amplify the mitochondrial cytochrome oxidase 1 (COI), mitochondrial cytochrome b (Cyt b). Bat acoustic recordings were made using an ultrasound detector and analysed using the software BatSound Touch. Phylogenetic analysis was performed using software Molecular Evolutionary Genetics Analysis Version 11 (MEGA 11) and Population Analysis with Reticulate Trees (POPART). Morphometric analyses, acoustic analysis and principal component analysis (PCA) of morphometric parameters were done in R software. The current known distribution of H. pomona is restricted to the SWG, and the species was elevated to endangered status in IUCN red list due to the current restricted range. However, no genetic studies have been conducted to confirm the split. Present study results confirm that H. pomona and H. gentilis are genetically distinct species. Within the SWG, the Palghat gap is a potential biogeographic barrier for H. pomona. The present study compared the forearm length (FA), length of first phalanx of third metacarpal (1PH3MT), and length of fourth metacarpal (4MT) – (Morphometry), and frequency of maximum energy FmaxE (Acoustics) of H. pomona subpopulations in the north and south of the Palghat gap and found significant variation, indicating that they are phenotypically distinct. However, the PCA result indicated that these subpopulations are cryptic. Overall, phylogenetic analysis of H. pomona, which was recently split from H. gentilis solely based on morphology, was done by comparing mitochondrial cytochrome oxidase 1 genome, which showed a clear difference between the two species. Acoustic and morphometric analysis of the H. pomona subpopulations in the north and south of the Palghat gap revealed that they are phenotypically distinct. The PCA done on the morphometric parameters revealed that the subpopulations of H. pomona across the Palghat gap are morphologically cryptic.
Modelling habitat suitability and climate change impacts on Malabar Pied- Hornbill (Anthracoceros coronatus) of WG, India
(Department of Wildlife Science, College of Forestry, Vellanikkara, 2024-03-07) Gowri, C B; Nameer, P O
Climate change has become a pressing issue in the WG region, which is renowned as one of the most prominent biodiversity hotspots in the world. Due to significant changes in climatic conditions, there is a growing consensus that species are undergoing more rapid shifts and declines in their habitats than they did in the past (Dobrowski et al., 2013). The Malabar Pied-Hornbill (Anthracoceros coronatus) is a notable bird species found in the Western Ghats region of India. The present study aims to determine the patterns of species distributions shown by this particular species in the changing climate scenarios. Monthly Climate model data downscaled from CMIP6 for the future and present were downloaded from WorldClim (Hijmans et al., 2005). The projections were developed under different Shared Socio-economic Pathways (SSPs) like SSP 1-2.6, SSP 3-7.0 and SSP 5-8.5 (IPCC AR6, 2022) for the period of 2021-2040, 2041-2060, 2061-2080 and 2081-2100 at a resolution of 30 arc seconds. The Habitat Suitability Modelling (HSM) for this species was done using the maximum entropy (MaxEnt) algorithm. The MaxEnt model settings were obtained with the help of ENM evaluate tool in R and Akaike Information Criterion (AIC) was used to find the best performing model. Multicollinearity test was done to eliminate highly correlated variables and the model was built based on those variables. BIO 14 (Precipitation of the driest month) and BIO 9 (Mean temperature of highest quarter) was found out to be the most important variable for the model building of MPH. An area of 71,816.09 Km2 was predicted as suitable area for the species which is 8.78% of the background area. Only 8.34% of the suitable area fall under the protected area network. Under the future climate change scenarios, the species is predicted to have a net loss of the suitable habitat. Under SSP 1-2.6 climate change scenario, there is an expected loss of 45.88% of the total suitable habitat for the species. But under SSP 3-7.0 climate change scenario, the expected loss is 61.35% of the total suitable habitat. Meanwhile there is expected to be a net loss of 63.99% of the total suitable habitat for the species under the climate change scenario of SSP 5-8.5. To ensure the long term conservation strategy in favor of the selected species, realignment of the protected area network in the WG is recommended. Reduction of greenhouse gas emission and restoration of the degraded habitats are recommended as solutions for the adverse impact of climate change.
Plant diversity and microbial activity as a function of soil carbon stocks in selected homegardens in the midland laterites of Kerala
(Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2024-01-19) Athulya Tom; Divya Vijayan, V
In woody ecosystems, understanding the relationship between plant diversity, microbial activity, and carbon sequestration is crucial, particularly in the context of addressing climate change and promoting sustainable land management. Homegardens are traditional land use systems that evolved through the generation of crop intensification. Apart from the livelihood security and economic advantages, the homegardens play a vital role in delivering many ecosystem services. In this context, addressing the role of homegardens in terms of plant diversity, microbial activity, and carbon sequestration is essential for ascertaining their potential contributions to sustainable and environmentally friendly practices. With this background, the study was carried out to investigate the carbon flux in the soil aggregates and their functional relation with plant diversity and microbial activity in selected home gardens in the midland laterites at the College of Forestry during the period 2022-23. The research was conducted under five land use systems which include Small Homegarden (SHG 0.4ha), a Forest area (Fo) and Treeless open area (TrO) of the Agro Ecological Unit (North central laterite) of Kerala. The plant diversity of the various homegardens revealed that the Simpson index was high in the forest (0.90) and SHG (0.87) followed by MHG and relatively less in LHG (0.63). The result of the physico-chemical properties of the soil revealed that the bulk density was lower in the surface soil and increased with depth. The Mean Weight Diameter (MWD) indicated the structural stability of soil which depicted that the forest had MWD of 0.74 mm followed MHG (0.68mm) and SHG (0.63 mm) compared to an open area (0.57 mm). The available nutrient distribution in the land use systems showed a variable trend with available nitrogen and potassium higher in the forest followed by SHG due to high plant diversity and associated litter and root dynamics. The available phosphorus was higher in LHG and MHG compared to forest and SHG. Soil organic carbon per cent in the five depths under the landuse systems ranged from 3.78 to 0.09 per cent and depicted a significant difference between all the land use systems, greatly in the 0-20 cm depth, where forest reported high SOC followed by SHG. The SOC stock (Mg C ha-1) under different land use systems followed a trend of forest (202.21) > SHG (157.62) > MHG (135.79) > LHG (119.60) >TrO (24.29). Macroaggregates in the different land use systems were reported to have high carbon storage especially forest and SHGs compared to microaggregates or clay and slit fractions. The microbial studies of various land use systems indicated considerable variability. The bacterial populations were higher than actinomycetes and fungi in the different land use systems. Among the land use systems, forest had the highest microbial count and the bacterial and fungal population was on par with SHG. The seasonal variation of enzyme activities revealed higher dehydrogenase activity in forest followed by SHG. The microbial biomass Carbon (MBC) in the three homegardens was relatively good and on par with the forest. A random forest regression model was developed to understand the most important variable affecting soil carbon stocks and the result revealed that C: N ratio, followed by the Simpson index, clay and silt carbon influence the carbon stock. The hierarchical cluster analysis grouped the land uses into four clusters based on the Euclidian distance and average linkage method. The MHG and LHG were grouped into one cluster because of their similarity and all other land use remained as independent clusters. The SHG mimics forest, by the resemblance in numerous aspects, such as microbial activity, soil carbon stock, MBC, and enzyme activity. Thus, we can conclude that although SHG offer specific advantages due to the diverse plant species, efficient resource utilization and space optimisation, the overall sustainability and carbon sequestration potential of other homegardens classes can be improved with effective management practices. Homegardens can play a crucial role as a nature-based solution to mitigate climate change through various mechanisms that contribute to carbon sequestration, biodiversity conservation, and sustainable land management.
Comparative assessment of the spatial distribution and edaphic attributes of mangroves in Perumba and Puthuvype regions
(Department of Forest Resource Management, College of Forestry, Vellanikkara, 2024-01-25) Rohan, M S.
Mangroves are characterized by salt-tolerant vegetation thriving in tropical and subtropical coastlines. It provides critical ecological services and a source of livelihood for coastal communities. Globally, these crucial ecosystems are currently under threat due to the over-exploitation of natural resources. The mangroves in the state of Kerala have witnessed a drastic reduction in the area from seven hundred sq. km to a mere nine sq. km over the last five decades. Developmental activities and anthropogenic disturbances in the coastal areas are the major threats to these sensitive ecosystems. The knowledge of the extent of disturbance, the changes brought by the anthropogenic activities and their effect on the mangrove vegetation are the prerequisites for the sustainable management of these ecosystems. In this context, the present research work studied the extent of change in mangrove areas, variation in vegetation structures, soil and water properties among two contrasting regions namely, the Perumba river region with low and the Puthuvype region with high human disturbances. The Land Use Land Cover (LULC) classification for the current year has shown almost same percentage of mangroves to the total area in both the studied regions. In the present study, we used the three most widely used machine learning algorithms for the classification process. Among the machine learning algorithms studied, the Gradient Tree Boost (GTB) algorithm with a combination of Sentinel 1, 2 datasets and few spectral indices shown exemplary performance (88 % accuracy) in classifying mangrove areas. Change detection analysis showed a positive trend in mangrove cover in Perumba region (7.03 % increase) and contrarily a negative trend (66.51 % decrease) in the Puthuvype region during the study period (2013 - 2023). Phytosociological analysis figured out seven species belonging to four families in both Perumba and Puthuvype regions. The only difference in the species composition between the two regions is that Kandelia candel was found only in Perumba region, while it was replaced by Bruguiera gymnorhiza in the Puthuvype region. The common species present among these two regions were Avicennia officinalis, Bruguiera cylindrical, Excocaria agallocha, Rhizophora apiculate and Rhizophora mucronata. The Perumba region exhibits higher vegetation diversity indices when compared to the Puthuvype region. Perumba region exhibited higher seedling, tree, and sapling density, indicating a healthier mangrove ecosystem. In both regions, the majority of trees belong to the girth xii class of 20-30 cm. Further, Important Value Index (IVI) identified Avicennia officinalis as a dominant species followed by Rhizhophora mucronata in both the regions. Soil analysis showed a significant variation for chemical properties between the regions studied. Electrical conductivity, soil organic carbon, available nitrogen, available potassium, sodium, magnesium, lead, and chromium levels were recorded higher values in the Perumba region. Meanwhile, available phosphorus content was found higher in the Puthuvype region. In addition, biological properties viz, actinomycetes, bacteria, and fungi populations were higher in the Perumba region. Moreover, water analyses also revealed a maximum electrical conductivity, salinity and turbidity in the Perumba region. Altogether, the study showed a declining mangrove population in the Puthuvype region due to significant changes in the mangrove ecosystem brought by the intense anthropogenic interventions in the mangrove ecosystem, necessitating immediate action for the restoration of this fragile ecosystem.
Standardisation of macro - proliferation technology for mass production of selected bamboo species of Kerala
(Department of Silviculture and Agroforestry, College of Forestry , Vellanikkara, 2023-12-10) Devi, S R; Jamaludheen, V
Macro-proliferation is the technology where plants are multiplied by separating the rhizomes in a way that each part contains a shoot and root (Bainik, 2015). This method is useful to produce two to four bamboos in a single generation from a single sapling. This process can be continued by further multiplying the macroproliferated bamboo by following the same process. In the case of Bamboo, where the flowering cycle is large and the availability of viable seeds is limited this method of macroproliferation has a huge advantage. This can be used for the large scale propagation of bamboo, as it is economical, has minimal labour requirements and suitable procedure. In this study, three species of bamboos are selected which include Bambusa balcooa, Ochlandra setigera, Dendrocalamus asper. The planting stock of Bambusa balcooa and Dendrocalamus asper were obtained from GrowMore Biotech Ltd, Hosur, Tamilnadu. The plants were six months old produced by tissue culture and hardened and grown in the polythene bag of size 4’’x 8’’. The seedlings of Ochlandra setigera was obtained from Kerala Forest Research Institute, Peechi, Thrissur. The collected seedlings were kept in the shade house of Tree Nursery and regular watering was done except on rainy days. The weedings were carried out at regular intervals. After six months of growth, the seedlings of selected species were subjected to macro proliferation. Seedlings were separated and roots were dipped overnight in a solution containing the 0, 100, 250 and 500 ppm of IBA (Indole 3 Butyric Acid, make Merk), and NAA (Naphthalene Acetic Acid, make SRL) for plant growth hormone treatment. Three NPK doses (2.5, 5 and 7 g each of NPK) were applied per seedlings to evaluate the effect of fertilizer on the tillering and rooting. The seedlings without growth regulators and fertilization will be kept in control. The complex NPK fertilizer in the ratio 18:18:18 was used for the study. The fertilizer was applied after the establishment of seedlings and before the appearance of new tillers. The propagules were transplanted in polythene bags containing the medium soil, sand and cow dung in a ratio of 2:1:1. Potting media was properly filled with care to make sure that the seedlings have a strong base to grow upon with water-holding capacity and sufficient nutrients. The propagules were watered uniformly two times a day for the first three days and then watered one time every day. Different shoot growth parameters, root growth parameters and moisture content levels were studied in this research. In the case of Bambusa balcooa, pertinent to shoot growth attributes, the maximum number of tiller growth is observed in IBA@100ppm for 7.5g (6.33), where the maximum number of nodes (7.00), collar diameter (4.81 cm), total seedling length (45.00 cm), and internodal length (8.00 cm) is registered in NAA@500ppm for 2.5g. The maximum number of leaves (24.46) is observed in NAA@250ppm for 7.5g and the maximum leaf area (19.00 cm2) in IBA@250ppm for 7.5g. The root growth attributes of Bambusa balcooa infers maximum value in terms of root length (max) (26.00 cm), root length (min) (4.67 cm) and root number (32.00) for NAA @ 100 ppm for 2.5g, IBA@100ppm for 5.0g and NAA@250ppm for 2.5g respectively and the minimum value for root length (max) (12.00 cm), root length (min) (1.60 cm) and root number (6.00) are observed in NAA@500 ppm for 7.5g. The maximum moisture content of Bambusa balcooa stem (5.18%), root (0.77%) and leaf (0.40%) are observed for NAA@100ppm for 5.0g, IBA@500ppm for 5.0g and NAA@100 ppm for 2.5g respectively and the minimum value for moisture content of stem (0.31) for NAA@500ppm for 5.0g and minimum moisture content of root (0.77%) and leaf (0.40%) for NAA@500ppm for 7.5g. On comparing the shoot growth attributes of Ochlandra setigera, the maximum number of tiller growth is observed in IBA@100ppm for 2.5g (4.67), where the maximum number of nodes (3.75), collar diameter (5.49 cm), total seedling length (35.03 cm), internodal length (10.08 cm), number of leaves (7.64) and leaf area (43.33 cm2 ) is registered in NAA@500ppm for 7.5g, NAA@100ppm for 7.5g, NAA@500ppm for 7.5g, IBA@100ppm for 2.5g, NAA@100ppm for 2.5g and NAA@500ppm for 2.5g respectively. The root growth attributes of Ochlandra setigera infer maximum value in terms of root length (max) (28.67 cm), root length (min) (4.50 cm) and root number (21.50) for NAA @ 500 ppm for 2.5g, NAA@100ppm for 7.5g and IBA@100 ppm for 2.5g respectively and the minimum value for root length (max) (18.67 cm), root length (min) (2.50 cm) and root number (9.00) is observed in IBA@100 ppm for 5.0g, IBA@100 ppm for 2.5g, and NAA@500ppm for 7.5g respectively. The moisture content of the parts of Ochlandra setigera registers, the maximum moisture content of stem (7.43%), root (1.18%) and leaf (1.62%) for NAA@100ppm for 7.5g, and NAA@100ppm for 2.5g respectively and the minimum value for moisture content of stem (1.34%), root (0.07%) and leaf (0.37%) for NAA@100ppm for 7.5g, NAA@100ppm for 5.0g, and IBA@500ppm for 7.5g respectively. With respect to, sprouting attributes of Dendrocalamus asper on treatment, most of the seedlings didn’t survive, so a comparison was carried out with the survived seedlings under IBA @100ppm for different fertilizer levels with the control. On comparing the shoot growth attributes the maximum number of tiller growth (5.0) is registered for 2.5g @NPK and the minimum for control treatment (1.5). With respect to the number of nodes (4.23), collar diameter (4.11cm), number of leaves (6.79), total seedling length (29.70 cm), internodal length (7.47cm) and leaf area (52.25cm2), the maximum value is registered for the control treatment. The root growth attributes of Dendrocalamus asper infer maximum value in terms of root length (max) (31.70 cm) for 2.5g, root length (min) (3.40 cm) for 2.5 and 7.5g and root number (32.50) for control treatment respectively and the minimum value for root length (max) (22.25 cm), root length (min) (2.75 cm) for control treatment and root number (23.00) 7.5g of fertilizer dosages respectively. The moisture content of stem (6.81%), root (0.40%) and leaves (0.33%) of Dendrocalamus asper infers the maximum value in control treatment and the minimum value for moisture content of stem (0.62%) and leaves (0.14%) for 7.5g and moisture content of root minimum for treatment at 5.0g of fertilizer dosages respectively. The Bambusa balcooa, Ochlandra setigera and Dendrocalamus asper respond differently to the treatments. The survival percentage of the seedlings with respect to the treatments followed as Bambusa balcooa > Ochlandra setigera > Dendrocalamus asper. The species' sprouting performance followed the Ochlandra setigera > Bambusa balcooa > Dendrocalamus asper. On comparing the influence of the planting hormones, NAA has more influence on Bambusa balcooa and Ochlandra setigera where the NAA treated Dendrocalamus asper fails to survive. The majority of sprouting attributes also infer a negative correlation with the fertilizer dosages.
Development of wood derived bioplastics and its physico-mechanical characterization
(Department of Forest Products and Utilization, College of Forestry, Vellanikkara, 2024-11-26) Bharath, M R.; Vishnu, R; Vishnu, R
The global market for bioplastics is rapidly expanding, driven by the increasing demand for biodegradable polymers, especially in emerging economies. Despite only comprising 1% of the annual plastic production, bioplastics offer significant environmental benefits by reducing CO2 emissions and enabling new end-of-life management options such as composting. The development of wood-based bioplastics (lignocellulosic bioplastics) represents a sustainable alternative to traditional petrochemical plastics, addressing both environmental and waste management challenges. Utilizing lignocellulose biomass not only transforms waste into valuable materials but also supports a circular economy, fostering sustainable development and environmental stewardship. These materials, abundant and non-edible, are a major source of renewable organic matter from agricultural and industrial activities. In this background the study ‘Development of wood derived bioplastics and its physico mechanical characterization’ was formulated with objectives as to develop wood derived bioplastics and evaluate its physical and mechanical characteristics. The study comprises in two sections, development of lignocellulosic bioplastics (LCBP) and its characterization. For the production of LCBP various raw materials like mixed sawdust and Melia dubia sawdust have been used and evaluated. Among these, sawdust from Melia wood was found as a suitable raw material for producing lignocellulosic bioplastic. Starch films were produced using corn starch and glycerol as plasticizer, to compare its properties with wood derived bioplastics. The sawdust was treated with deep eutectic solvent (DES), which was prepared using choline chloride and oxalic acid to deconstruct the structure of wood and to obtain the lignocellulose slurry. When water is added to the slurry, lignin gets re-attached with the cellulose fibres, producing a dense and compact arrangement. It is later ultrasonicated using a probe ultrasonicator at 800W for 30 minutes. The slurry is then mixed with recycled cellulose fibres (RCF) obtained from recycled paper in various concentrations and hot pressing is done for 15 minutes to yield the final LCBP. The scanning electron microscope (SEM) and transmission electron microscopy (TEM) images of LCBP showed a continuous lignocellulose matrix with dispersed cellulose fibers. Processed into micro/nanofibrils, the cellulose was encased by lignin, acting as a natural binder. The tensile strength test revealed that incorporating RCF enhanced the mechanical strength of the bioplastics. Samples with the highest RCF content exhibited the greatest tensile strength, attributed to optimal reinforcement, while those with the lowest RCF content demonstrated the weakest strength due to inadequate cellulose reinforcement. The Fourier Transform Infrared Spectroscopy (FTIR) spectrum showed similar peaks in sawdust, and lignocellulose slurry, showing the preservation of lignin even after treatment. X-ray diffraction (XRD) patterns indicated the cellulose I crystalline structure was preserved post-treatment, with the bioplastic showing a 42.43% crystallinity index which is 19.43% higher than raw wood powder. The thermal gravimetric analysis (TGA) curve showed increased thermal stability for LCBP when compared with starch film. As lignocellulose content increased, the bioplastic's water contact angle increased upto 105.30 for pure lignocellulose, indicating strong hydrophobicity. Higher lignin content also reduced water absorption due to lignin's hydrophobic nature. The biodegradability of the LCBP was studied using soil burial test and was compared with starch film and compostable plastic (ISO 17088) and found that starch film achieved 88% biodegradation in one week and was fully degraded in 14 days. LCBP showed 50% degradation in one week and 55.97% in two weeks, outperforming compostable bioplastic (1.59% degradation in two weeks). From the study it was found that the LCBP has very good physical and mechanical properties which is comparable with commercially available alternatives and shows very good degradability, thereby addressing other environmental concerns too.

PG Thesis

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