Browsing by Author "Gopakumar, S"

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Analysis of urban microclimates (UMCs) in Thrissur corporation using micro meteorological measurements and remote sensing data
(Department of Natural Resource Management, College of Forestry,Vellanikkara, 2022-10-12) Mamatha, N A; Gopakumar, S
Global urban population is increasing at an alarming rate. Unplanned and inadequately managed urbanization has profound effects on microclimate. The unplanned urbanization could transform cities and townships into urban heat islands (UHI) one of the most evident climatic modifications in urbanized areas. The increased heat in the cities affect the environment and the thermal comfort of organisms. Understanding the urban climate is very necessary to make the cities sustainable. The objective of this study is to investigate and analyse the urban microclimates in Thrissur Corporation limits and to understand their linkages with urban greenery. This study will also examine and analyse the perceptions of urban residents in the study locations about different aspects of climate change. The LULC map of Thrissur Corporation was prepared based on NRC guidelines in ArcGIS using Landsat 8 satellite data acquired from Earth Explorer. Three urban LULC class were selected to take the in-situ temperature measurement. Ambient air temperature and relative humidity were measured during the study period in morning 7.30 am and afternoon 2.30pm, the data is further used to assessing urban heat island intensity. Highest temperature was recorded from LULC urban compact, that constitute the commercial center of the city, where the region occupied by highly dense buildings, dense population, heavy traffic, pavement and other impervious structures. The temperature recorded from other urban LULC classes such as urban_sparse and urban- _vegetation is comparatively low. The least temperature was recorded from urban_vegetation. It was noted that temperature difference between LULC classes such as urban_compact, urban_sparse and urban_vegetation is prominent during afternoon compared to morning air temperature. The urban heat island intensity ranging between 0ºC -5.53ºC was observed in LULC class urban_compact. Land surface temperature (LST) and normalized difference vegetation index (NDVI) of various LULC classes in Thrissur corporation was estimated and it was found that the LST is maximum in the LULC urban_compact, where the NDVI values are minimum. Whereas the LST is minimum in the LULC cropland_paddy where the NDVI is maximum. Among the three urban classes, viz. the urban_compact, urban_sparse and urban_vegetated the minimum LST was estimated in the LULC urban_vegetated. To understand the linkage between microclimate and urban greenery correlation test was done between the LST and NDVI values estimated in various urban LULC classes. A strong negative correlation was observed in LULC urban_vegetated (-0.35). The correlation coefficient estimated in urban_sparse and urban_compact is - 0.46 and -0.41 respectively. A perception study was done among 30 people residing in urban area. The way people think about climate change is crucial to developing strategies to address the problem. Among the respondents, majority (80%) have the opinion that the human interventions, predominantly deforestation are the major cause of climate change. On the other hand, 20 % of the respondents are not sure whether human interventions only causes climate change or any natural causes are also there. Chi-square test was done to find the association of respondent’s age and gender with their perception on various aspects of climate change, and no association was found between the respondents age and gender with their perception on climate change. From the study it was understood that the UHI has been developed in the core of Thrissur muncipal corporation belongs to LULC class urban_compact that includes places like East fort, High road and North bus stand. The study also observed the role of urban vegetation in mitigating the urbanization induced climatic modification. However a more focused study considering extra parameter such as air quality , wind speed and wind direction etc will give a better understanding of UMC. In the wake of rapid urbanization UMC study would be helpful in modelling cities for sustainable development.
Cause - consequence analysis of human-wildlife conflict in Wayanad district, Kerala
(Department of Forest Management and Utilization, College of Forestry, Vellanikkara, 2017) Ajaisanker, K; Gopakumar, S
Human-wildlife conflicts is now a paradox for foresters and policy makers across the globe. In Kerala, interaction between humans and wildlife is affecting many lives and livelihoods. The damage caused by these interactions are drastic, it can vary from crop loss in a small area to human deaths. For the people living near the protected areas crop losses and livestock losses due to raiding by wildlife are a serious social and ecological concern as this can create an anti-wildlife lobby in the long run. So, understanding the social dimensions of such conflicts is also important to frame effective mitigation strategies. The study titled “Cause-consequence analysis of human-wildlife conflict in Wayanad district, Kerala” conducted during 2015-2017 tried to discern the nature, frequency, distribution and intensity of human-wildlife conflicts in Wayanad district and to understand the causative factors involved in the conflicts. The study was also intended to suggest suitable mitigatory measures to enhance human-wildlife coexistence in Wayanad district. A total of 120 households were interviewed from four locations in Wayanad namely Meppadi, Odapallam (SulthanBathery), Bhoothanam (Chedleth) and Thirunelli. Detailed interviews using pre-tested questionnaire was conducted and Participatory Rural Appraisal (PRA) tools like timeline, problem tree and vulnerability mapping was employed at each location for collecting additional information. Crop raiding was found to be the major type of conflict occurring in the district. Over the past years there occurred a shift in the farming practices with banana becoming a popular crop at the expense of the traditional crops. Most of the respondents lived in the close proximity and practiced agriculture and also occasionally integrated livestock in their farms. More palatable crops in the forest fringes along with domestic animals and plentiful water attracted the wildlife to the farmlands. Plantations of teak, eucalyptus etc, together with the invasive alien weed species has smothered the natural vegetation thereby reduced the natural food resources triggering animal migration. Reduced rainfall, droughts and forest fires that the district now increasingly experience has further reduced the availability of resources for the wildlife. These were found to be the major causes leading to conflicts. People were well aware of the forest laws and the attitude of the farmers to wildlife was positive. They believed in coexistence and conservation to be unavoidable for human existence. Enrichment of the habitat and fencing around the farmlands were favoured as the best mitigation measure. People did support the compensation schemes and insurances, provided they were adequate and immediate. The study outlines the possible role of various stakeholders such as farmers, Non- Governmental Organisations, Research institutions, Local self-governmental institutions and governments in improving the conflict mitigation process.
Cause-consequence analysis of human-wildlife conflict at Nemmara forest division, Kerala
(Department of Forest Management and Utilization, College of Forestry, Vellanikkara, 2017) Anand, R; Gopakumar, S
A study titled “Cause-consequence analysis of human-wildlife conflict in Nemmara forest division, Kerala” was conducted during 2013-2017. The main objectives of the study were to portray the nature and distribution of human-wildlife conflict, study the land use and land cover change pattern. Another objective of the study was to assess the attitude and awareness of the people including the victims of human-wildlife conflict about forest conservation and human- wildlife conflict. The observations of the study would be made useful to evolve location specific management strategies at Nemmara Forest Division. A detailed pre tested questionnaire was used to gather information regarding socio-demographic details, land use and land cover change patterns, human wildlife conflict data, crop farming details and also attitude and awareness of the people. A total of 398 individuals were surveyed from Alathur, Kollengode and Nelliyampathy ranges of the forest division. Participatory Rural Appraisal (PRA) methods such as oral history, time line and problem tree methods were used to collect additional information. The study found out that major conflict areas were along the fringes of the forest areas. The type of conflict even though was mainly crop raiding, the nature of damage and the animal causing the damage were found to be different in different ranges in the forest division. Over the past 30 years there was significant change in the land use and land cover in the division. Over all, cropping pattern has changed from food crops to cash crops. The number of wild animals has increased and this was portrayed as the main reason for human-wildlife conflict. The people found the forest department as the best responsible agency to look up to take action regarding conflict mitigation and were also ready to join hands with them to resolve such issues. Even though the people had a positive attitude towards forest conservation and wildlife they were not satisfied with the conservation policies and human-wildlife conflict mitigation schemes of the government. The people did not favour compensation or insurance schemes as a mitigation strategy towards crop raiding mainly because of the low compensation amounts and difficulty in applying for such schemes. Site specific plans, based on the data generated from this study can be used to develop not only location specific plans but also both animal as well as people specific plans for conflict management and mitigation.
Characterisation of phytopathogenic fungi in nursery seedlings of Tectona grandis L.F, Swietenia macrophylla King and Cassia fistula L. In Central Kerala
(Department of Forest Management and Utilisation, College of Forestry, Vellanikkara, 2017) Kiran Mohan; Gopakumar, S
Characterization,Documentation and Management of fungal diseases of selected forest nursery seedlings of Kerala
(Department of Forest Resource Management,College of Forestry, Vellanikkara, 2024-06-04) Kiran Mohan; Gopakumar, S
Disease free planting stock significantly ensures better field survival, thereby reducing the burden of economic loss and meeting the targets of climate change mitigation. Teak (Tectona grandis L.f.), Indian beech (Pongamia pinnata (L.) Pierree), custard apple (Annona squamosa L.), guava (Psidium guajava L.), and Indian laburnum (Cassia fistula L.), which are extensively used for afforestation programs in Kerala, are severely affected by fungal pathogens at the nursery stage. Hence, an investigation was undertaken to identify the major fungal diseases associated with the above mentioned seedlings in Kerala and to assess the efficacy of selected fungicides and bio-control agents through in vitro and in vivo studies. A purposive sampling survey was conducted in 40 forest nurseries across the state during summer (Feb-May), monsoon (June-Sept), and post-monsoon (Oct-Jan) seasons in 2021 to monitor the occurrence of fungal diseases and collect diseased samples. Out of the seven major fungal diseases, three from teak, and one each from the other four tree crops were observed respectively. Major fungal diseases noticed from teak seedlings include teak leaf rust (TLR), teak die back (TDB), and teak leaf spot (TLS). Pongamia foliar disease (PFD) from Indian beech, annona die back (ADB) from custard apple, guava leaf spot (GLS) from guava, and cassia die back (CDB) from Indian laburnum are the other selected major diseases. Teak leaf rust (TLR) was the most common and severe foliar disease observed in teak from various nurseries across the state and irrespective of the five agro-ecological zones (AEZs), the maximum Percent Disease Index (PDI) and Percent Disease Severity (PDS) (60.0% and 52.8%, respectively) recorded from Chettikkulam (AEZ IV- High Hills) in the monsoon season. Teak die back (TDB) disease (PDI 62%) was observed only from Edayazham (AEZ I- Coastal Plain) during the pre-monsoon period. Teak leaf spot (TLS) was noticed only from Kudayathoor nursery (AEZ III- Foothills) during the pre-monsoon season. In Indian beech, PFD was observed from different nurseries irrespective of AEZs during the study period, and Chettikkulam (AEZ IV- High Hills) recorded the maximum PDI (80.0%) and PDS (63.2%) in the monsoon. The major disease of custard apple seedlings, i.e., ADB, was observed from different nurseries, and the maximum PDI (55.0%) was recorded at Kanakappalam (AEZ III- Foothills). Guava leaf spot (GLS) was noticed as the common disease in guava seedlings during the survey, and the maximum PDI (60.0%) and PDS (55.0%) were recorded at Varanadu nursery (AEZ I- Coastal Plain). In Indian laburnum, CDB was found to be a common disease throughout the state, and at the location Kattamudy (AEZ IV- High Hills), it recorded the maximum PDI (50.0%). Based on the available data during the study period, TLR showed a positive correlation with temperature and a negative correlation with rainfall. However, PFD showed a negative correlation with temperature and a positive correlation with rainfall and ADB showed a positive correlation with rainfall as well as relative humidity. In the case of GLS, no common trend was detected, and CDB showed a negative correlation with relative humidity. The typical orange colour urediniospores on the backside of the affected teak leaf characterizes TLR symptoms. Meanwhile, TLS is noticed as scattered black spots with a greyish center. Whereas TDB originates as leaf blight and subsequently spreads throughout the seedlings. Symptoms of PFD are observed as irregular chlorotic spots on the adaxial side and black dot-like sporodochia on the abaxial side. Leaf yellowing, followed by inward curling and the further spread of a necrotic area throughout the seedling, is the typical symptom of ADB. Meanwhile, GLS is noticed as grey to cream-colored blighted region surrounded by black, brown, or violet round margin. In the case of CDB, the initial symptom of leaf blight later spreads throughout the seedling. The pathogenicity of the major foliar diseases (TLR, TLS, PFD, GLS) was proven using Mycelial Bit Inoculation Method (MBIM), Micro Droplet Inoculation Technique (MDIT), and inoculation with the infected leaf method. Spore suspension method and mass multiplied pathogen in the substrate method were adopted for major root diseases (TDB, ADB, CDB). The obligate parasite (TLR) was identified as Olivea tectonae based on the morphological characters of urediniospores and all other major pathogens were identified upto the species level based on cultural as well as morphological characters, coupled with characters of amplified gene regions (ITS region and LSU region). The TDB pathogen was thus identified as Colletotrichum fruticola, TLS pathogen as Corynespora cassiicola, PFD pathogen as Cladosporium tenuissimum, ADB pathogen as Colletotrichum siamense, GLS pathogen as Colletotrichum siamense, and CDB pathogen as Alternaria alternata. In vitro evaluation studies revealed that carbendazim 12% + mancozeb 63%, mancozeb, and propineb stood out against major foliar diseases. However, in vivo experiment results showed that carbendazim 12% + mancozeb 63%, mancozeb, hexaconazole, and Trichoderma asperellum were observed to be efficient against major foliar diseases. Similarly, carbendazim 12% + mancozeb 63%, mancozeb, Bordeaux mixture, and hexaconazole showed promising results against major root diseases during in vitro as well as in vivo experiments.
Climate-forest fire linkages in selected protected areas in Kerala
(Academy of Climate Change Education and Research ,Vellanikkara, 2020) Sreedevi, K; Gopakumar, S
Co-managed forestry as a function of stakeholders perceptions and demographic profile in eastern Attappady, Kerala
(Department of Forest Management and Utilisation, College of Forestry, Vellanikkara, 2014) Remya Raghavan; Gopakumar, S
A study titled “Co-managed forestry as a function of stakeholders’ perceptions and demographic profile in Eastern Attappady” was carried out during 2013-2014. The main objectives were to analyse the performance of the co- managed forestry activities from the perspectives of the various stakeholders, and to explore the link between socio-economic variables and variations in members’ perceptions about the success of these initiatives. A pre-tested questionnaire was used to gather information on socio-demographic characteristics of the stakeholders’, performance and impacts of co-managed activities on forest and livelihood status. A total of 183 respondents from three Joint Forest Management Committees (JFMCs) and four Vana Samrakshana Samithies (VSS) drawn from seven locations, namely Sambarcode, Paloor, Kalkandy, Puthur, Bhomiampady, Sholayur, and Gonjiyur in Eastern Attappady, were surveyed. Additionally constraints of JFMC and VSS institutions were also studied using Participatory Rural Appraisal (PRA) tools such as Venn-diagram, Problem-causes linkages and SWOC analysis. The study found that the JFMC and VSS activities positively influenced the ecology of the area. However, there was a significant contrast between the perceptions of the JFMC and the VSS members with regards to its influence on the livelihood of the local people. The JFMC members’ reported that the co-managed activities, increased the household income and encouraged women participation, which reduced many social evils. Whereas, the VSS members opined that the performance of VSS activities was not upto the JFMC activities in improving the socio-economic status of its members. The JFMC was observed to be a better performer than VSS from the perspectives of stakeholders on the ecological and social aspects. Further, the study observed that the success of co-managed programs depended on education, age, income, occupation and social participation. All these significantly contributed to higher levels of women participation and livelihood opportunities. Social participation also influenced the attitude of people towards the forest and co-managed activities. The major constraints of JFMC, were lack of integration with other departments, unnecessary political interference and lack of group feeling among members. The major constraints for VSS were lack of income generating opportunities, lower level of people participation and constant transfer of VSS secretary.
Development and characterization of natural gum base Nanocomposite
(Department of Natural Resource Management, College of Forestry,Vellanikkara, 2019) Meghana Rose Joseph; Gopakumar, S
Natural gum based bionanocomposite film using babul gum obtained from Vachellia nilotica .L and cellulose nanofibrils (CNF) extracted from bamboo culms via steam explosion cum acid treatment was developed for biomedical and packaging applications. Alkali treatment (using NaOH) followed by bleaching (using sodium hypochlorite) of chopped bamboo culms resulted in removal of impurities like pectin, lignin, hemicellulose and other organic compounds. Steam coupled acid treatment of the bleached cellulose pulp resulted in the depolymerization and defibrillation of the fibres to produce cellulose nanofibrils. The structural, morphological, chemical, and thermal properties of CNF were analysed using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FT-IR), X-Ray Diffraction (XRD) and Thermogravimetric Analysis (TGA). TEM and SEM images showed that the CNF was composed of network like structure of long fibrils of nanocellulose having the size of few micrometres in length and 50-60 nm in width. The CNF had a crystallinity of 54.46% which was greater than that of the raw bamboo fibre (41%). The chemical composition of the raw fibre and the CNF was analysed by FT-IR micrographs. TGA showed that the CNF was thermally more stable than the raw fibre and the results of peak temperature of 10 and 20% weight loss of raw fibre and CNF substantiated the same. The effect of CNF content (1, 3, 5, and 10 wt% based on gum) on the thermal, mechanical, water solubility, contact angle, and moisture content of nanocomposites was studied. Properties of babul gum film such as mechanical properties were improved significantly (p<0.05) by combining with CNF. The TGA analysis revealed that the composites had more thermal stability than the pristine gum film. The tensile and elastic modulus of composites increased significantly (p<0.05) when the concentration of the CNF increased in the gum matrix, while the elastic property decreased with the addition of CNF. The contact angle was found to be increasing with increasing the concentration of CNF added to the gum 64 matrix resulting in less hydrophilic composite with high CNF content. The moisture content tested for the composite films showed no significant difference with the addition of CNF. Water solubility tested showed around 90-95% of the film was dissolved completely in water. The CNF obtained from bamboo fibre can be used as reinforcing agent for the preparation of bio-nanocomposites and they can have a high potential for the development of completely biodegradable edible films which can be used for biomedical applications and packaging.
Economic evaluation of mangrove ecosystem services in Thrissur district
(Department of Forest Resource Management , College of Forestry, Vellanikkara, 2024) Nayana, N C; Gopakumar, S
Economic evaluation of mangrove ecosystem services in Thrissur district
(Department of Forest Resource Management, Vellanikkara, 2024) Nayana, N C; Gopakumar, S
Ecotourism carrying capacity of Nelliampathy, Palakkad, Kerala
(Department of Forest Resource Management, College of Forestry, Vellanikkara, 2024-02-26) Rathna, V.; Gopakumar, S
Ecotourism is globally embraced as a niche segment of sustainable tourism, transforming conventional mass tourism and increasingly being recognized as a strategy for sustainable forest management in natural areas. However, to address the potential threats arising from an excessive influx of visitors and inadequate regulations in these areas, it is imperative that effective ecotourism planning and management must establish and uphold optimal thresholds, commonly denoted as the “carrying capacity of destinations”. Despite its importance in managing visitor numbers, many key ecotourism destinations currently do not adhere to this concept. This study focused on assessing the ecotourism carrying capacity (ETCC) for one of the major hill-based ecotourism attractions in Kerala, ‘Nelliampathy’, which faces immense pressure from tourists, by taking into account various site-specific physical, biological or ecological and social factors. Tourist's perceptions were also obtained through a survey conducted with 91 respondents with a pre-tested questionnaire, scheduled every fortnight from June to September. Furthermore, a brief study on the valuation of the use (recreational) and non-use values of Nelliampathy was carried out. The study established Effective Carrying Capacity (ECC) estimates for various destinations: Government Orange Farm, Kesavanpara, Seetharkundu, Pakuthippalam KFDC, Minnampara and Karappara Bridge at 587, 302, 153, 110, 40 (approximately 5 trips per day) and 8 visitors per day, respectively. The occupancy rate of destinations revealed that Karappara far exceeded the carrying capacity, followed by Minnampara and Seetharkundu. While the current visitation rates are actually below these estimates for some destinations like Kesavanpara and Govt. Orange Farm, there is a risk of congestion and overcrowding, particularly during peak seasons and holidays. ETCC assessment underscores the importance of improving the management capacity in terms of personnel, infrastructure and equipment and judicious monitoring of limiting factors that could reasonably increase the carrying capacity of these sites. Extended projection periods, especially for KFDC and Govt. Orange Farm could be strategically utilized to alleviate tourist pressure. The tourist profile indicated a significant majority from Kerala (92.31%), mainly comprising students (25.27%) and middle-aged individuals (46.15%) with a literate background (41.76%), favouring exclusive weekend day trips to Nelliampathy (79%). Overall, tourists held a positive perception about natural attractions and environmental characteristics of Nelliampathy, though a neutral stance was observed regarding travel-related concerns and other tourist assistance services. Despite its aesthetic beauty, Nelliampathy received negative feedback due to limited accessibility to emergency services. Tourists typically used personal cars (47%) and often engaged in group tourism with friends and family. Substitute destinations suggested include Munnar, Wayanad, Parambikulam Reserve and Silent Valley Park. The anticipated increase in tourist flows in Nelliampathy necessitates a re-evaluation of destination ticketing systems. Visitor willingness to pay (WTP) reflected environmental awareness, providing an opportunity for engaging tourists in destination improvement initiatives. This comprehensive understanding aids in shaping the future ecotourism management plan for Nelliampathy and the study offers a potential model for assessing carrying capacity at other ecotourism sites in the state
Effect of elevated CO2 concentration on growth and physiology of selected tropical tree seedlings
(Department of Forest Management and Utilisation, College of Forestry, Vellanikkara, 2010) Neenu Somaraj; Gopakumar, S
The present study entitled “Effect of elevated CO2 concentration on growth and physiology of selected tropical tree seedlings.” was carried out in College of Forestry, Kerala Agricultural University, Vellanikkara, Thrissur during the period 2008-2010. There are references that elevated CO2 typically increases tree seedling growth and has also modified physiological processes. Polybag seedlings of five economically important tree species were exposed to 500-550 ppm CO2 concentration and another similar set of plants were raised under ambient atmospheric CO2 condition (370-380 ppm). The growth rates and physiology were observed for eight months. Tree seedlings under elevated CO2 concentration put in more height and collar diameter than the seedlings under atmospheric CO2.A higher leaf production and larger leaf area was recorded in seedlings under elevated CO2 concentration. The different levels of CO2 also showed significant effects on the total dry matter content. However, interactions between two CO2 levels and five tree seedlings had no significant impact on the shoot: root ratios throughout the study period. The different CO2 treatment did not significantly affect the relative growth rate (RGR), net assimilation rate (NAR), specific leaf area (SLA) and the leaf area ratio (LAR) of seedlings. However, both CO2 levels showed significantly different impact on the leaf weight ratio (LWR) of seedlings. Seedlings under elevated CO2 recorded lowest number of stomata compared to seedlings under atmospheric CO2 concentration. The varying CO2 concentrations showed significant effect on the rate of photosynthesis of the tree seedlings. Chlorophyll a and Chlorophyll b in tree seedlings was not significantly influenced under different CO2 concentrations. However, total chlorophyll content showed significant influence. Seedlings under elevated CO2 recorded lowest soluble protein content compared to seedlings under atmospheric CO2 concentration. Hence, CO2 enrichment technique can be used as an economically viable nursery technology for production of more healthy and vigorous planting stock to meet the increasing demand for social forestry /agro forestry programme.
Effect of seed treatments and shade on seedling growth dynamics of pongamia pinnata (Linn.) Pierre in the nursery
(Department of Forest Management and Utilisation, College of Forestry, Vellanikkara, 2009) Gururaj Sankeshwar, B; Gopakumar, S
The present study entitled “Effect of seed treatments and shade on seedling growth dynamics of Pongamia pinnata (Linn.) Pierre in the nursery” was carried out in College of Forestry, Kerala Agricultural University, Vellanikkara, Thrissur during the period of 2007-2009. In the first phase, seeds were subjected to six pre-sowing treatments. GA3 treated seeds recorded highest Germination percentage, Final Mean Daily Germination (FMDG), Germination Value (GV) and Peak Value (PV). The effect of seed treatments were observed on various biometric parameters like height, collar diameter, number of leaves and primary branch. GA3 treated seeds recorded better height and collar diameter during the initial stage of seedling growth. At the end of study cold water seed treatment was found to be effective in enhancing seedling growth. However, none of the pretreatments was observed to cast a significant effect on biomass production and root growth parameters in Pongamia pinnata seedlings. In the second phase, to evaluate seedling growth under different shade conditions, seedlings were placed under 25 per cent shade, 50 per cent shade, 75 per cent shade and full sunlight situations. Shade treatments did not significantly influence height and collar diameter growth of Pongamia pinnata seedlings in the nursery. The maximum leaf production and primary branch production was observed in seedlings kept under full sunlight and 50 per cent shade respectively. Under seventy five per cent shade seedlings produce maximum shoot and root dry weight. The shoot: root ratio and total biomass was also maximum for seedlings kept under 75 per cent shade. Root length and spread were maximum under 50 per cent shade. However, shade did not significantly effect secondary root production. Shade levels also did not influence Pongamia pinnata seedlings with respect to relative growth rate and leaf area. However, Specific leaf area and Leaf area ratio was higher under 25 per cent shade. Highest Specific leaf weight was observed for seedlings under full sunlight. Shade had no significant effect on leaf weight ratio of seedlings. Maximum stomatal number was recorded under 25 per cent shade. In the nursery stage shade is casting an overriding influence with regards to various growth parameters of Pongamia pinnata.
Explorative study and capacity development on human wildlife conflict management in selected forest tracts of Kerala: Final project report
(Kerala Agricultural University, Thrissur, 2017) Gopakumar, S
Fire impacts on vegetation and soil in a forest ecosystem in Wadakkancherry forest range, Thrissur forest division, Kerala
(Department of Natural Resource Management, College of Forestry, Vellanikkara, 2023-04-18) Vivek Noel N.; Gopakumar, S
Fire is being used as a tool in forest management and protection in several parts of the world. A forest fire is an unplanned, uncontrolled and unpredictable fire in an area of combustible vegetation. The after effects of forest fire includes air pollution, destruction of forests and wildlife, altered species composition, outbreaks of pests and diseases etc. The frequency of wild fires around the world increases with changing climate. Considering the growing importance of tropical forest ecosystems and also because of its fire susceptibility, it is relevant to study the effects of forest fire on vegetation and soil in a forest ecosystem. The present study was undertaken in Chembikkunnu area of Poongode section of Wadakkanchery forest range in Thrissur forest division in state of Kerala. The study was carried out to assess the impacts of an unplanned forest fire on the vegetation and soil physico-chemical and biological properties in the fire burnt areas of Poongode section of Wadakkanchery forest range of Thrissur forest division. Concurrently the study also compared and contrasted the changes in vegetation and soil between burnt and control areas over a time period of six months. Physico- chemical properties of soil viz. soil moisture, bulk density, water holding capacity, soil pH, soil organic carbon, total nitrogen and total phosphorous showed marked differences between the fire affected classes themselves and between control areas. Other soil properties like soil texture, soil electrical conductivity and total potassium remained without any significant effects after the fire. Soil physico-chemical properties showed differences between pre-monsoon and post monsoon season. Soil moisture content (%) decreased with increase in frequency of fires. In the pre-monsoon conditions, the bulk density of the newly burnt area increased to 0.94g/cm3. Water holding capacity of the fire affected areas at the depth of 0-15 cm increased to 39.23% in pre-monsoon season. Soil pH of the newly burnt areas increased to 6.85 immediately after the fire. Soil organic carbon (%) followed the trend (NBP>OBP>CP). Total Nitrogen (%) and total Phosphorous (ppm) content of the burnt plots was higher compared to the control area. As vegetation intercepts rain and reduced the kinetic energy of rain water, soil erosion (Tonnes/ha/yr) of the study area followed the trend (NBP (0.13)> OBP (0.07)>CP (0.03)). Total enumeration of regeneration was carried out in the 10m x 10m plots on a monthly basis. 37 plant species representing 20 families were recorded. Among them there were 11 tree species, 2 grass species and 4 species of ferns. Hemidesmus indicus, Pycnospora lutescens and Drynaria quercifolia were found only in the fire affected plots. The Shannon- Weiner diversity index of saplings in the month of July are in the range of (1.45-2.37) while it is more for seedlings (2.76-2.96). The Sorrensen similarity indices of July (0.81(saplings), 0.91(seedlings)) points to the increased number of common species among plots. The increased evenness and reduced diversity in the fire affected plots are mainly attributed to the invasion of weeds like Chromolaena odorata, Mimosa diplotricha and grass species like Pennisetum polystachyon. Unavoidable physical, chemical and biological changes happening to the soil after every fire incident are potentially able to influence the soil fauna. Darkling beetles, broad shouldered water striders, dung beetle and centipedes were recorded only from the fire affected plots. Ants were present in all the plots in both the seasons. An increase in the number of individuals was observed after the monsoon. The hard coated beetles registered their presence in significant number in the burned classes and the soft bodied animal like earthworm, centipedes and millipedes were absent immediately after the fire but appeared after the monsoon suggesting that the temperature variation in the ecosystem might have made them to move away. The outcomes of present study necessitate longer duration study in different tropical forest types for more comprehensive understanding of the post fire dynamics of tropical forest ecosystems.
Floral biology and seed technological aspects of Jatropha curcas Linn.
(Department of Forest Management and Utilisation, College of Forestry, Vellanikkara, 2008) Gopakumar, S; Puttaswamy, H
Floristic and edaphic attributes of a shola forest ecosystem in Mankulam forest division Kerala
(Department of Natural Resource Management, College of Forestry, Vellanikkara, 2020) Abin M Thadathil; Gopakumar, S
Floristic and edaphic attributes of three land use systems in Wayanad, Kerala
(Department of Forest Management and Utilisation, College of Forestry, Vellanikkara, 2011) Aneesh, K S; Gopakumar, S
The present study was conducted in Thollayiram area of South Wayanad Forest Division of Wayanad district. The objective of the study is to compare the various floristic and edaphic attributes of three land use systems, viz an ecologically fragile land (EFL), a section 5 land (as per section 5 of Kerala Preservation of Trees Act (1986) and vested forest found in South Wayanad Forest Division. A total area of one hectare was surveyed in each of the three land use systems. The floristic study revealed that species richness of these land use systems were 40, 26 and 32 respectively. The major associations of trees in the ecologically fragile land were Melicope lunu-ankenda- Litsea oleoides- Litsea wightiana and Diospyros nilagirica. In section 5 land, the major associations are Litsea wightiana- Dillenia bracteata and Diospyros nilagirica whereas the vested forest is dominated with Palaquium ellipticum, Myristica beddomei, Dimocarpus longan and Mesua ferrea. Total basal area of vested forest is 44.56 m2 followed by ecologically fragile land (37.47 m2) and section 5 land (33.60 m2). By comparing the Shannon –wiener index of these land use system, vested forest recorded the highest value (2.96) followed by ecologically fragile land (2.93) and section 5 land (2.80) whereas Simpson indices are 0.93, 0.91 and 0.92 respectively. Regarding vegetation structure, a typical three storeys was noticed for ecologically fragile land and vested forest but section 5 land has only two storeys. Texture analysis revealed that soil texture of these land use systems are sandy loam. The pH values of the soil ranges from 3.84 to 4.79. The higher value of bulk density was recorded for section 5 land (1.46 g cm-3) followed by ecologically fragile land (1.34 g cm-3) and vested forest (0.88 g cm-3). There is no significant difference in the values of organic carbon and available potassium across three land use systems whereas available phosphorous was significantly higher in vested forest. The information regarding diversity of ecologically fragile land in Thollayiram will be helpful to the state forest department in designing better strategies for the long term conservation of this ecosystem.
Functional diversity of an evergreen forest ecosystem of Vazhachal forest division, Kerala
(Department of Forest Management and Utilisation, College of Forestry, Vellanikkara, 2016) Deepakkumar, R; Gopakumar, S
Impact of invasive alien Plants on understorey vegetation in Tholpetty range of Wayanad Wildlife Sanctuary
(Department of Natural Resource Management, College of Forestry, Vellanikkara, 2019) Harilal, K; Gopakumar, S
A study titled “Impact of invasive alien plants (IAP) on understorey vegetation in Tholpetty Range of Wayanad Wildlife Sanctuary” was undertaken to understand the distribution characteristics of selected invasive alien plant species (IAPS) viz., Lantana camara L., Senna spectabilis (DC.) H.S. Irwin and R.C. Barneby and Chromolaena odorata (L.) R.M. King & H. Robin in the three vegetation types (Plantation, NF, and Vayal) of WS I part of the WWLS. The additional objective was to assess the impact of these IAPS on the native plant communities in these vegetation types. In the WS I area, L. camara invasion was rampant, except in the southern regions. Higher invasion was seen in the Kaimaram and Thirulkunnu forest sections. C. odorata invaded all the four sections viz. Kaimaram, Dasanghatta, Thirulkunnu and Bavali. S. spectabilis invasion was heavy in the Kaimaram section near the boundary of Thirunelli RF, and in the boundaries between Nagarhole TR and Kaimaram section. In all the three vegetation types, the density of Chromolaena was high, while it was lowest for Senna. The density of Chromolaena in NF, Plantation and Vayal was respectively 3734.11 ± 5.65, 8457.64 ± 27.52 and 7761.17 ± 9.74 stems/ha. The density of Lantana in NF, plantation and Vayal was respectively 1061.17 ± 2.75,334.11 ± 1.02and 215.29 ± 0.50stems/ha. The density of Senna in NF, plantation and Vayal was 414.11 ± 1.55, 589 ± 2.67 and 34.11 ± 0.21stems/ha respectively. In the Vayals, Senna invasion, though minimal, could be noticed. Chromolaena had the highest percentage cover in both plantation (24.58 ± 3.06) and Vayal (46.19 ± 4.03). In NF, Lantana (19.46± 3.43) had the highest percentage cover. In all the three vegetation types, Chromolaena had the highest frequency and abundance. Out of the total 140 plant species identified from the WS I region, number of species recorded in each weed category types like L, C, S, LC, CS, LS, LCS and Control were 67, 96, 20, 64, 9, 7, 14 and 113 respectively. Vis-a-vis the impacts of IAPS in NF, highest MSR (Mean Species Richness) was seen in Control (weed-free area), followed by L (Lantana invaded) and C (Chromolaena invaded) regions. The lowest MSR was in LCS (Lantana, Chromolaena, and Senna invaded) and LS (Lantana and Senna invaded) regions. In plantation, highest MSR was seen in Control (weed-free area) and the lowest in L (Lantana invaded) area. In Vayal too, highest MSR was observed in control, followed by C (Chromolaena invaded) and lowest in LC (Lantana and Chromolaena invaded) areas. All three IAPS negatively influenced the native species richness, although no specific declining trend in species richness could be observed. Among the three IAPS, C. odorata had the biggest impact on the species richness of native species in both NF and Vayal. In the plantations, L.camara had the biggest impact on species richness. Canopy openness and percentage cover of IAPS were found to be positively correlated. In NF and Vayal, Lantana showed highest correlation with canopy openness, while in plantation, Chromolaena showed highest correlation with canopy openness. In plots where Senna and Lantana occurred together, plant species richness decreased from 67 to 7. Similarly, when Senna and Chromolaena came together, species richness dropped from 96 to 9. This probably indicates a dominating interference of Senna on the recruitment of native species which needs research attention. Left unmanaged, Senna will soon become a major “biological pollutant” of Wayanad WLS.