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Open Access
Comparative performance of three exotic tree species in social forestry strip plantation in Trichur Social Forestry Division
(College of Forestry,Vellanikkara, 1990) Nandakumar, G; KAU; KrishnanNair, V R
A study was conducted in 1987-88 on the social forestry strip plantation on the premises of the Sitaram Textile mills Ltd. In the Trichur Social Forestry Division of Kerala State; to compare the performance of three exotic fast growing tree species, Casuarina equisetifolia, Acacia auriculiformis and Eucalyptus tereticornis in social forestry strip plantation. Comparisons were made on the three year old plantation in respect of growth, biomass production and impact on the soil and undergrowth. General observations were also made on the tree form, occurance of pests and diseases and wild life habitat improvement. The site of experiment was being used for dumping coal cinders and other wastes from the textile mill and was barren before planting. The experiment was laid out in RBD with five replications. The results obtained in the study have been summarised below : At the end of the third year Acacia auriculiformis had a DBH of 4.56 cm followed by Eucalyptus tereticornis with 3.82 cm and Casuarina equisetifolia with 1.62 cm. The mean annual diameter increments were 1.44 cm/year in Acacia, 1.20 cm/year in Eucalyptus and 0.51 cm/year in Casuarina. Acacia had more primary branches (27/tree) followed by Eucalyptus (23/tree) and Casuarina (17/tree). The first primary branch was 3.18 m above the ground in Eucalyptus, 2.22 m in Acacia and in 2.16 m in Casuarina. Acacia had 100% survival at the third year while Eucalyptus had 88%. But Casuarina had only 72% survival rates. In growth as well as survival, Acacia auriculiformis was found to be the best among the three. Eucalyptus tereticornis was found superior to Casusrina equisetifolia while the latter was the least impressive of the three. The total biomass yield at the third year was 98.438 mt (drymatter)/ha in Acacia auriculiformis, 48.424 mt/ha in Eucalyptus tereticornis and 12.506 mt/ha in Casuarina equisetifolia. Acacia had a mean annual biomass increment of 32.813 mt/ha. MAI of Eucalyptus was 16.141 mt/ha while that of Casuarina was only 4.169 mt/ha. In biomass production too, Acacia auriculiformis was found superior to Eucalyptus tereticornis and Casuarina equisetifolia. Of the three species Casuarina equisetifolia with a light intensity on the floor of 49.5% was the least shading one, followed by Eucalyptus tereticornis with 43.6% and Acacia auriculiformis with 30.6%. Eucalyptus was found to permit luxuriant undergrowth, so also casuarina. The above ground phytomass was 1.431 kg drymatter/m2 in Eucalyptus and 1,176 kg/m2 in Casuarina. But Acacia was found to inhibit undergrowth (0.183 kg/m2 ). Even the little undergrowth that was permitted by it comprised mostly of its own seedlings. The undergrowth in Eucalyptus comprised mostly of woody species (65.5%) while that of casuarina comprised mostly of grasses (68.5%). The presence of coal cinders had caused a rise in the soil pH, organic matter content, available Nitrogen content and available phosphorus content of the soil. The lowest pH value in the top soil was found in Acacia soil 4.31. Eucalyptus soil had 4.69 and Casuarina soil had 4.94 compared to the barren laterite (5.16) and the barren laterite with coal cinders (5.32). At the depth of 30-45 cm, the pH values were 4.85 in Acasia soil, 5.17 in Casuarina soil and 5.32 in Eucalptus soil. The barren laterite had a pH of 5.24 and in the barren laterite with coal cinders it was 5.42. The pH at 60-70 cm depth was 4.88 in Acacia soil 5.24 in Casuarina soil, 5.33 in Eucalyptus soil, 5.36 in barren laterite and 5.52 in barren laterite with coal cinders. All the three species reduced the pH of the soil. But Acacia auriculiformis was found to lower the pH of the soil more than the other two. pH increased with the depth in all the treatments. The organic carbon contents in the top soils were 0.57% in Acacia, 0.41% in Eucalyptus, 0.49% in Casuarina, 0.39% in barren laterite and 0.43% in barren laterite with coal cinders. The organic matter content was found to decrease as depth increased in all the treatments. There was a general rise in the organic carbon content of the soils due to the impact of the three species with the maximum in Acacia soils and the minimum in Casuarina soils. The available Nitrogen content in the top soil was 1277 kg/ha in Acacia, 1165 kg/ha in Eucalyptus, 1098 kg/ha in Casuarina, 874 kg/ha in barren laterite and 963 kg/ha in barren laterite with coal cinders. There was a reduction in the available Nitrogen content as the soil depth increased in all the treatments. All the three species caused an increase in the available Nitrogen content of the soil, the highest being observed in Acacia auriculiformis followed by Eucalyptus tereticornis. The available Potash content of the soils did not record any change under the different species. The available phosphorus contents of the top soils were 92.7 kg/ha in Casuarina, 90 kg/ha in Eucalyptus, 81.5 kg/ha in Acacia. 79.3 kg/ha in barren lateric and 87.4 kg/ha in the barren laterite with coal cinders. There was reduction in the content of the nutrient as depth increased in all the treatments. In Acacia soils the content of the available Phosphorus had decreased. Regarding the general observations, Acacia auriculiformis showed pronounced branching habits while Eucalyptus and Casuarina had more or less clean boles. Pests and diseases were not observed excepting the pink disease (c.o. Corticium salmonicolor) in Eucalyptus. Crows and rodents were the principal representatives of wild life in the plantion. Honey bees commonly foraged the inflorescence of Acacia. Acacia auriculiformis proved itself to be a highly promising tree for energy plantations and for afforesting sites dumped with coal cinders and for sites offering little protection from anthropogenic influences and grazing. It also improved the organic matter content and available nitrogen content of the soil and was free from graziers. But at the same time there were also unwelcome effects due to Acacia such as increasing the acidity of the soil and supressing undergrowth. It also tended to be highly branching. Eucalyptus tereticornis also was found to be good in growth and biomass production and could be recommended for similar sites. The species also enriched the soil by increasing the contents of organic carbon and available Nitrogen. Though it too reduced the pH of the soil, the species was found to support luxuriant undergrowth and was spared by graziers. Casuarina equisetifolia was a less suitable species for such a site as seen from the performance of the species. It suffered heavily from browsing and showed lesser survival growth and yield. But the species increased the organic carbon content and available Nitrogen content of the soil and permitted luxuriant undergrowth especially grasses.
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
Stand density regulation in even aged teak plantations
(Faculty of Agriculture, College of Forestry, Vellanikkara, 1990) Prasoon, Kumar; KAU; Mohankumar, B
A teak density management diagram was constructed using the stand inventory data on teak collected from Parambikulam, Thrissur and Chalakudy areas. Density management diagram is a graphical representation of the stand growth through time, in terms of density and quadratic diameter, volume, height and Reineke’s stand density index. A size –density based index such as Reineke’s stand density index incidentally provides a good biological basis for the translation of management objective into levels of growing stock. Stand density index (SDI) incidentally is also independent of site quality and age. The data – set also revealed that Parambikulam is a better site for teak followed by Thrissur and Chalakudy. The maximum SDI for teak was found to be 600 which probably covers all possible combinations of size and density included in the data – set. The use of diagram for designing two alternate density management regimes for a hypothetical stand is illustrated. Designing a density management regime requires the translation of management objectives into appropriate levels of growing stock. Maximization of volume production and maximization of individual tree growth are the two alternate but contrasting silvicultural strategies in this context. For maximization of volume per unit area the level of the growing stock should fall in the zone 11 of the Langsaeter’s curve. On the other hand, if the land management objective is to maximize individual tree growth, then trees should not experience much competition (preferably in zone 1 of the Langsaeter’s curve). So, in the former case the levels of growing stock will be naturally higher than that of latter. After fixing the appropriate upper and lower levels of size – density relations the stand is allowed to grow till it reaches upper limit and then thinned down to the lower limit. This process is repeated as many times as necessary. The diagram has diverse utility from designing alternate density management regimes to comparing the results of optimization analyses. However, it suffers from some shortcomings such as lack of memory, prediction of same rotation age irrespective to the path taken by stand, rotation ending before culmination of periodic annual increment, the assumption of single maximum size – density relationship and slight bias of the model with respect to the independent variables outside the range of the data base. However, with more work many of these defects could be over come.
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.

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