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Open Access
Evaluation of provenances for seedling attributes in teak
(Department of Tree Physiology and Breeding, College of Forestry,Vellanikkara, 1996) Jayasankar, S; KAU; Luckins Babu, C
A randomized block design experiment involving the performance of selected provenances ie., Arienkavu, Konni, Malayattur, Nilambur, Parambikulam, Wynad and Thrissur (Local provenance) of Tectona grandis Linn. F. initiated during June, 1995 was used for the present investigation. The objective of the study included qualifying the seed characters, growth parameters, physiological and anatomical characters, root growth potential, field establishment and also elucidating the extent of nutrient uptake pattern, besides characterising the nutrient status dynamics. Seed characteristics like mean number of seeds per kg, 100 seed weight, purity percentage and individual seed parameters were found to vary significantly among the provenances tested. Parambikulam was found to be superior to other provenances, while local provenance recorded the least values for most of the parameters. Germination behaviour of teak provenances in the laboratory varied considerably among provenances. The overall performance was better in Konni which recorded a high germination percentage, peak value and MDG. Malayattur was showed to be inferior in these respects. Shoot, root growth, biomass allocation pattern, RGR and NAR were followed the trend that, Parambikulam, Nilambur and Malayattur consistently registered better growth rates in most of the stages of experimental period while, local provenance recorded the least values. Physiological parameters like LDR, transpiration rate, leaf water potential and RWC were influenced considerably among the provenances. Anatomical character like stomatal frequency was also varied among provenances throughout the period. Concentration of nutrient in the different plant parts and uptake pattern were found to be higher in Malayattur, Nilambur and Parambikulam especially with a high magnitude of N use efficiency. Local provenance registered a low accumulation of nutrients in different plant parts. Root growth potential studies showed significant variation among the provenances. Malayattur and Nilambur provenances had relatively higher values in RGP. While, Thrissur recorded a poor growth performance in this respect.
Open Access
Biomass production and resource partitioning in silvi-pastoral systems
(College of Forestry, Vellanikkara, 1993) Suman Jacob, George; KAU; Mohankumar, B
A randomized block design experiment involving factorial combinations of four fodder species : Pennisetum purpureum (hybrid napier), Brachiaria ruziziensis (congo signal), Panicum maximum (guinea grass) and Zea Mexicana (Teosinte) and four tree species (Leucaena leucocephala, Casuarina equisetifolia, Acacia auriculiformis and Ailanthus triphysa initiated in June 1988 was used for the present investigations. The study was pursued with the objective of quantifying the biomass production potential of selected forage species grown in association with tree components after canopy closure, comparing the productivity of different tree components grown in silvopastoral systems; characterizing the micro-site enrichment and nutrient cycling aspects of silvopastoral systems, analysis the partitioning of solar radiation among the different components of the system and elucidate influence regarding the nature of root interactions in silvopastoral systems. The tree attributes such as biomass, height, DBH and crown diameter were in the order acasia > leucaena>casuarinas>ailanthus and the fodder biomasses were in the order hybrid napier> guinea grass > congo signal>teosinte. The concentration of N,P and K in the above ground portion decreased in the order: leaves >Branches >bole. The N-fixing trees, in general, had lower nutrient – use efficiencies. Amount of photosynthetically active radiation interception by the tree canopy was a cardinal factor effecting the herbage yield a direct correspondence was lacking. All the three N-fixing species had markedly higher soil nitrogen status. Soil organic matter, K and P were also higher under the tree canopy. Recovery pattern of 32p isotope injected in the soil revealed that 65 to 85 percent of the fine roots responsible for water and nutrient absorption were concentrated in the 0-15 cms layer of the soil profile. However, 32P recovery from the tree monocultures was generally low suggesting stimulatory effect of nutrient absorption by trees in presence of an associated field crop. The rate of litterfall amount of detritus produced ranged from 1.92 Mg ha-1 yr-1 (ailanthus) to 6.2 Mg ha-1 yr-1 (acacia). Relatively lower contents of nitrogen and phosphorus in the litter recorded during the dry period (March-April). Regarding the inter – specific variations with regards to litter decomposition rates, casuarina and leucaena litter decomposed at a faster rate than acacia and leucaena. The nitrogen and phosphorous contents of the decomposing litter increased during the one – year decay period for all the species. Although widely accepted and yield initial N, lignin or initial lignin/nitrogen could not be directly related to decay rate coefficients in the present study.
Open Access
Response of selected forestry and agroforestry tree seedling to water stress
(Department of Tree Physiology and Breeding, College of Forestry, Vellanikkara, Thrissur, 1996) Rajesh, N; KAU; Ashokan, P K
An experiment was conducted at the College of Forestry, Kerala Agricultural University, Vellanikkara, Thrissur during the period from 1994 to 1995 with seedlings of Acacia mangium Willd., Ailanthus triphysa (Dennst.) Alston., Pterocarpus marsupium Roxb., Swietenia macrophylla King and Tectona grandis L.F. to study the response of the species to water stress. The results showed that the growth characteristics and Physiological behaviour of all the five species were adversely affected due to water stress. Among the five species studied S. macrophylla was the most sensitive species and did not show much adaptations to tolerate water stress. Eventhough A. mangium showed adaptations like quick closure of stomata, thick cuticle and low chloroplast disintegration when exposed to water stress, growth characteristics were found to be adversely affected due to water stress. So the species has to be tested for its water stress tolerance in a long term experiment. Pterocarpus marsupium was also found to be sensitive to water stress and all the growth characters were adversely affected. However, it showed relatively high net photosynthesis and relative growth rate. Ailanthus triphysa was the least sensitive species to water stress. Considering the relative growth rate and net photosynthesis, A. triphysa and P. marsupium are rated to perform well under dry situations. Among the five species studied T. grandis seedlings showed symptoms of permanent wilting when the water stress was increased from moderate (~ 5 Bar SMT) to severe (~ 10 Bar SMT) levels. Other species did not show permanent wilting even when the plants were not watered for nine days condinuously (S3). Growth characteristics in T. grandis was not much affected due to mild (S1) levels of water stress eventhough the plants wilted and dried under severe water stress (S3).
Open Access
Growth and nodulation characteristics of selected indigenous tree legumes
(Department of Tree Physiology and Breeding, College of Forestry, Vellanikkara, 1997) Harikrishnan, Nair G; KAU; Asokan, P K
An investigation was carried out to study the nodulation characteristics of seven Indigenous/ naturalized tree legumes in Trichur district of Kerala State. The homesteads of five selected panchayats viz. Pananchery, Madakkathara, Nadathara, Puthur and Ollukkara of the district were surveyed to assess the natural nodulation and to collect nodules for isolating Rhizobium.• The response of these tree legumes to inoculation with local isolates and commercial cultures of Rhizobium were done by seed inoculation and growing the seedlings in a glass house. In a separate experiment, the soil collected from the base of the nodulating tree were also evaluated as an inoculant. The inoculation studies were laid out in CRD with ten replications.
Open Access
Habitat utilisation of animals and their parastic burden with special refference to elephant in Vazhachal Forest Division , Kerala, South India
(Department of Wildlife Science, College of Forestry, Vellanikkara, 1996) Animon, M M; KAU; Jacob, V Cheeran
An investigation was carried out in Vazhachal Forest Division, Kerala, South India during 1994-95 to identify the habitat utilization and seasonal movement patterns of the wild elephants (Elephas maximus indicus). Estimating the population of elephants, finding out the impacts of elephants on woody vegetation, identifying the internal parasites of elephants, studying the need and type of mineral supplements and assessing the importance of Vazhachal as a zone of tourism were also aimed by this study. Habitat utilisation and seasonal movements were studied by indirect methods based on dropping count. Population was estimated by a direct simultaneous count. Vegetation damages were assessed by demarcating plots of size 25x25 m randomly in the study area. Parasitic analysis of fresh dungs was done by centrifugal sedimentation technique and microscopical examination. Mineral mixtures of different concentrations were placed in the area to study the preference for minerals. Data on income from Vazhachal was collected to assess the importance of Vazhachal as tourism centre. Seasonal movements reflected the habitat utilization patterns. Preference of habitats by elephants varied with season. Moist deciduous forests were preferred most in winter season whereas it was least preferred in summer. Evergreen forests were preferred over the moist deciduous forests only during summer season. Acacia plantations were most preferred in summer seasons and was least preferred in first rainy season. Preference for teak plantations were comparatively high during summer and first rainy season. A seasonal movement from thickly vegetated east end of the division to open and secondary forest dominated west end was evident. Great variations in dung densities of individual transects indicated a continuous movement of elephants in the study area. Elephant population at Vazhachal comprised of 155 elephants with a sex ratio (male : female) of 1:6.5 and a crude density of 0.38 elephant/km2. Debarking and breaking tops were the main forms of damages in Teak (Tectona grandis), Papitta (Pterocymbium tinctorium) and Albizia (Albizia falcataria) plantations. Breaking of tops and pushing over accounted for main damages in Bombax (Bombax ceiba) plantations. Damages were comparatively less in moist deciduous and evergreen forests. A total of 35species were found to be debarked in whole of the study area. Elephants preferred mineral mixture with high concentration of minerals and this stresses the need of supplementation of required minerals. Majority of the dungs analysed showed the presence of parasites strongylus and tape worm, indicating heavy infection. Increase in income from tourism in Vazhachal indicates the increasing importance of Vazhachal forests in the tourism map of Kerala. The tourist influx was found to vary with changes in rainfall pattern.
Open Access
Ecophysiological studies in disturbed forest ecosystem: a case study at Pattikkad
(College of Forestry, Vellanikkara, 1993) Nameer, P O; KAU; Asokan, P K
Moist deciduous forests of Kerala are prone to comparatively more biotic interference, as it occupies a buffer zone between human population and evergreen forests. An investigation was carried out at Pattikkad range of Peechi- Vazhani wildlife Sanctuary, in Trichur Forest Division, Kerala. The objectives of the present study were to understand the floristic, structural, functional, physiological, edaphic and micrometeorological changes accompanying degradation. Three experimental plots namely highly disturbed ( PATK – BT), partially disturbed (PATK – MD) and more less undisturbed (PATK – TP) were identified taking into consideration the proximity to human settlement. Each plot had a size of 10000 m2 and were subdivided into quadrats having 100 m2 each and observations on frequency, density, basal area, Importance Value Index (IVI), diversity indices, height – diameter relationships, regeneration pattern, litter quantification, litter decomposition, phenology, leaf area, leaf area index, light infiltration, physic-chemical properties of soil, soil moisture and soil temperature were recorded at periodic intervals for an year. The results indicate that the moist deciduous forest tend to become a semi – evergreen forest it left undisturbed for several years. The undisturbed (PATK – TP) plot recorded maximum density (882), in 143 species (48 families) whereas the density is only 154 in the highly disturbed (PATK – BT) plot. The number of species at PATK – BT is only 31 (19 families). The species diversity is also very high in the undisturbed plot (Simpson’s index = 0.97 ; Shanon –Weiner’s index = 5.97) whereas the Simpson’s index and Shannon – Weiner’s index are 0.92 and 4.16 respectively for PATK – BT. The height – diameter relationship clearly show that the set of the future is more or less absent in the disturbed plots. The regeneration survey reveals that the regenerating community is sparse in the disturbed plots. While the disturbed plots (PATK – BT and PATK – MD) had 3825 and 5045 seedlings per hectare the undisturbed (PATK – TP) plot had 26,500 seedlings per hectare. The litter production was found to be positively correlated with basal area. The rate of litterfall ranged from 6.14 t ha-1 to 8.66 t ha-1 in the moist deciduous forests. The decay rate was fastest in the disturbed (PATK – BT) plot (‘K’ value = 0.26) and slowest in the undisturbed (PATK – TP) plot (‘K’ value = 0.17). The light infiltration to the forest floor was maximum in the highly disturbed (PATK – TP) plot (44.42 mol m-2 s-1 ). The PATK – TP had a leaf area index of 4.04 and that of PATK BT was only 1.06 While most of the leaves in the undisturbed plot belonged to notophyllous (leaf size = 20.25 cm2 to 45.00 cm2 ) type of leaves, that of distributed plots were mesophyllous (leaf size = 45.00 cm2 to 182.25 cm2 ). The physic – chemical properties of the soil were better in the undisturbed plot when compared to the disturbed plots. The gravel content was 23 to 33 per cent at PATK – BT whereas it was 22 to 23 per cent at PATK – TP. Soil was more acidic (pH 5.51 to 5.57 ) at PATK – TP, whereas at PATK – BT the pH varied from 6.13 to 6.14. The organic carbon at undisturbed (PATK – TP) plot ranged between 1.4 to 3 per cent while in the highly disturbed (PATK – BT) plot ranged from 0.9 to 2 per cent. N, P and K also followed a similar pattern. The soil moisture was always maximum in the undisturbed (PATK –TP) plot. The soil moisture varied between 14 per cent (March) to 50 percent (July). The soil moisture at the highly disturbed (PATK – BT) plot was always the minimum. The values varied between 3 per cent (March) to 30 per cent (July). The undisturbed (PATK – TP) plot consistently recorded minimum soil temperature throughout the year when compared to the disturbed plots. The values varied between 220 C (July) to 280 C (April). Whereas in the highly disturbed (PATK – BT) plot the soil temperature was always high. The soil temperature recorded at PATK – BT ranged between 250 C (July) to 360 C (April).
Open Access
Pheno-morphological studies of selected tree species in a tropical forest ecosystem
(Department of Tree Physiology and Breeding, College of Forestry, Vellanikkara, 1994) Gopakumar, S; KAU; Luckins Babu, C
A pheno – morphological study was carried out in pattikad Range of Trichur Forest Division, Kerala. Two groups of ten species each, where each group represented the moist deciduous and the semi – evergreen tract, were used for the present investigations. The study was initiated in March 1993 and was continued for a calendar year upto February 1994. The study was pursued with the objectives of supplementing information on the different phonological cycles of the commonly found species of this forest area. Along with this, the important macromorphological features of these trees were noted. An attempt was also done to understand the tree architectural principles of these species. The pattering of the phonological events like flowering, fruiting, leaf fall and leaf flushing, no doubt, are partly under endogenous control. However, in general, the timing of these life cycle events were noticed to follow a climatic cue. The deciduous habit exhibited by the study species during the dry weather had an ecological significance, because it strongly helped the trees to tide over the moisture limiting summer months. Likewise, dry season flower and fruit production shown by the species might be a part of a much complex adaptive strategy developed by these species through the course of competitive evolution. Apart from these climatic triggers, there exists possibilities of several, other external stimuli, that might have favoured these important seasonal cycles. However, the cardinal factor effecting these events would be the climatic factors, through its direct and indirect influences on the physiological mechanisms of these woody plants. Regarding tree architecture, it was noted that all the species build up through a progressive duplication of their basic architectural units. This architectural metamorphosis continued from seedling stage upto the death of the tree. Branch production and initiation of sexuality were intermediate events. However, the free expression of the architecture was found drastically affected, possibly due to the different stresses that perennial woody species encounters in its long life span.
Open Access
Incidence of tapping panel dryness in rubber in the small holdings of Meenachil Taluk
(Department of Plantation Crops and Spices, College of Horticulture, Vellanikkara, 1994) Sebastian Michael; KAU; Kesavachandran, R
The study was conducted to find out the extent of incidence of TPD and related parameters in the rubber growing small holdings of Meenachil taluk. Fifty four small holders who sell their produce as latex and representing different parts of the taluk were selected for the study. Holdings with trees tapped either on BO 1 or Bo 2 panel only were included in the study. The study revealed that the small holders have high preference for the clone RRII 105 due to its inherent capacity for faster growth, higher yield and disease resistance. Rainguarded tapping is not being practiced on a large scale, as only 35.19 per cent of the holdings resorted to this practice. Tapping intensity in the surveyed holdings was invariably 1/2S d/2, without any rest on Sundays. Planting density varied from 460 ha-1 to 550 ha-1 and density of trees under tapping varied from 300 ha-1 to 500 ha-1. Planting density upto 550ha-1 was found not to have any effect on bark thickness or incidence of TPD. The mean incidence of TPD, in terms of complete dry cuts, was 7.56 per cent for the clone RRII 105. During the initial four years of tapping, the incidence was below five per cent in the holdings surveyed. In the present study, positive correlation was observed between dry rubber yield per unit area and incidence of TPD. Mean bark thickness showed highly negative correlation with incidence of TPD. Also, bark thickness was found to have highly significant positive correlation with annual mean drc. But no correlation was observed between annual mean drc and TPD incidence. Bark consumption showed highly significant correlation with TPD incidence, and non significant correlation with yield. This indicates induction of TPD by recovery tapping without concomitant increase in yield. Thus comparable incidence of TPD was encountered in rainguarded and nonrainguarded holdings, without realizing comparable yield. Low incidence of TPD was observed in plantations with slower growth. High incidence of TPD was generally observed near house holds and cattle sheds, in low lying areas, banks of rivers and canals etc.
Open Access
Food and feeding habits of Asian elephants (Elephas maximus Linn.) - A case study of Idukki wildlife sanctuary
(Department of Wildlife Science, College of Forestry, Vellanikkara, 1994) Vinod, T R; KAU; Jacob, V Cheeran
The present investigation was carried out in Idukki wildlife Sanctuary, Kerala during 1992 – 94 with the objective of identifying the food plants of elephants and to study the feeding habits of the animal in its natural condition. The study also aimed at finding out how elephants acts as a seed dispersal agent and to estimate the elephant population in the study area. Information on food plants of elephants in the study area was obtained by direct observation. Activity time budget was also studied by direct observation. The proportion of time spent in grazing, browsing and debarking, were computed by observing the elephants in different habitats and noting the time spent on each category of feeding. Elephants in Idukki Wildlife Sanctuary were found to feed on 61 species of plants. About 38 per cent of the food plants belong to the family Poaceae. Barks of 24 species of trees were eaten. Fruits of Careya arborea and Dillenia pentagyna were also commonly consumed by elephants. Feeding accounted for 65.45 per cent of elephant activity in dry season whereas it was 80.77 per cent in wet season. Time spent in drinking varied from 2.73 per cent in dry season to 1.96 per cent in wet season. The seasonal difference in time spent in feeding is found to be significant whereas that of drinking is found to be non-significant. Grazing was predominant in both dry (63.89 per cent) and wet (71.43 per cent) seasons. Search for fresh elephant dung were made and undamaged seeds were collected. Trees were located and raw seeds were also collected and the germination rate was compared with raw seeds. Elephant in the area was found to act as a seed dispersal agent. A total of 682 seeds representing 4 species were collected from the elephant dung. Seeds of Dillenia pentagyna and Careya arborea were found to be most frequent and abundant in the dung examined. The germination rate was slightly higher in the ingested seeds as compared to the fresh seeds collected from the trees. A direct simultaneous count was made in the area. A total of 72 elephants were observed. The ecological density was estimated to be 1.6 animal/Km2 and crude density was about 0.9 animal /Km2. Herd size varied from 1 to 19 in wet season to 1 to 10 in dry season. The male-female ratio of adults was found to be 1:15.3. Dung density distribution showed a clear movement of elephants from the sanctuary to the adjoining areas.

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