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V. Subramanian , C. Buvaneswaran , K. Rajagopal , M. George

Abstract

Biomass production and nutrient cycling studies were carried out in a young teak (Tectona grandis L. f.) plantation of five year old (density 2,500 trees ha^-1). The trees attained an average girth and height of 23.1cm and 7.6m, respectively and the above ground biomass (agb) amounted to 76.9 t/ha, of which stem wood contributed 60%. The percentage of ischolar_main to agb was 20.5%. Investigations on nutrient content in the standing crop have shown that the per cent concentration of nitrogen (N), phosphorous (P), potassium (K), calcium (Ca) and magnesium (Mg) were highest in leaf. But on unit area basis, wood accumulated the major portion (39 to 60%) of all nutrients. Among the nutrients, maximum accumulation was accounted for Ca (1,619 kg ha^-1) and the minimum for P (178 kg ha^-1). With reference to nutrient return via litter, it was observed that the total litter produced was 4,574 kg ha^-1 and the nutrients returned amounted to 46 kg ha^-1 N; 3 kg ha^-1 P; 39 kg ha^-1 K; 86 kg ha^-1 Ca and 21 kg ha^-1 Mg. Studies on interception of rainfall and nutrient return through rain-wash have shown that among the nutrients return was highest for Ca (1.87 kg ha^-1) followed by Mg (1.09 kg ha^-1), K (0.98 kg ha^-1), N (0.36 kg ha^-1) and the least for P (0.11 kg ha^-1). Nutrient cycling on an annual basis was worked out for the plantation and it was found that of the total uptake of various nutrients (178kg N ha1 yr1, 248 kg K ha^-1 yr^-1, 387 kg Ca ha^-1 yr^-1 and 109 kg Mg ha^-1 yr^-1, 74 to 91% was retained in the non-photosynthetic biomass and the rest returned to soil. These results were compared with nutrient cycling in 20-year-old teak plantation and found that at younger age teak retains more nutrients in its biomass. As the plantation gets older, it retains less and returns more quantity of nutrients. These results suggest that as the age of plantation increases, teak becomes an eco-friendly species by not adversely affecting the ecology of the site.

Keywords

Nutrient Cycling, Young Teak Plantation, Coimbatore, Tamil Nadu

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K. Rajagopal , C. Buvaneswaran , V. Subramanian , M. George

Abstract

Studies on different pathways of nutrient return through litterfall and rain-wash were carried out in a young teak (Tectona grandis L. f.) plantation at five years age (Density 2500 trees/ha). The total litter produced was 4574 kg/ha and the nutrients returned amounted to : nitrogen - 46kg/ha; phosphorus- 3 kg/ha; potassium 39kg/ha; calcium 86kg/ha; and magnesium 21kg/ha. Studies on interception of rainfall have shown that, the total incident rainfall recorded for this study during the year 2000 was 1013 mm. Of which, 28.97% was intercepted by the canopy, while 7.66% was accounted for stemflow and 63.37% for through fall. With regards to nutrients return through rain-wash, it was found that, throughfall returned more quantities of all nutrients, than stemflow. Of the total return (litter + rain wash) of various nutrients, maximum amount (kg/ha) of return was accounted for calcium (87.40) followed by nitrogen (46.56), potassium (40.31), magnesium (22.13), and the least for phosphorus (3.31). Among these two pathways of nutrients return, litterfall contributed greater amount of all nutrients (from 95 to 99%), when compared to rain wash (0.8 to 4.9%). These results were compared and discussed with nutrients return and nutrient cycling in 20 years old teak plantation and suggest intensive silvicuItural practices in teak plantations during the initial stages of growth to enhance the productivity.

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K. Rajagopal , C. Buvaneswaran , M. George , P. Manivachagam

Abstract

Comparative studies on litter decomposition employing two methods - bag and non-bag, were carried out under teak plantation of age 30 years. Though a steady decline in decomposition of the litter occurred in both the cases, the rate of decomposition was faster in the non-bag method than that of the bag. The un-decomposed litter after a period of one year was 19.43% in non-bag method against 49.8% in the bag method. The decomposition coefficient (k) was higher in non-bag (1.638) when compared to bag method (0.697). With regard to nutrients in the decomposing litter, the concentration of different nutrients differed as the decomposition progressed. Among the nutrients (N, P, K, Ca and Mg), the release of potassium was faster when compared to others. Between the two methods the decomposition co-efficient (k) was greater for all nutrients in non-bag method.

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C. Buvaneswaran , M. George , S. Mohan

Abstract

Investigations carried out on stemflow, throughfall and interception in a 30-year-old Teak plantation (density 620 trees/ha) at Coimbatore Forest Division, Tamil Nadu have shown that, out of the annual rainfall of 1966.7 mm, 7.54% was accounted as stemflow and 51.20% as tbroughfall. Remaining 41.26% was accounted as interception. While maximum stemflow (8.68% of rainfall) and throughfall (56.71%) and minimum interception loss (34.61%) was recorded during the month of November; minimum stemflow (0.25% of rainfall) and throughfall (5.0%) and maximum interception (94.75%) was recorded during March, It was also found that the seasonal variation of rainfall influenced the stemflow and throughfall. Interception during South-West monsoon (June-August) was almost at par with average annual interception. But during North-East monsoon (September-November) the interception was much below the annual average. The results of the present study show that the interrelationship between rainfall, stemflow and throughfall in Teak is similar to that of broad leaved species like Shorea robusta. It was also found that the interception depends on parameters like crown form, density of the species, external structural features like bark characteristics and branching nature as well as rainfall pattern and other meteorological factors which influence the evaporation.

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J. Singh , M. George , G. Varghese

Abstract

Litter production and nutrients return in a tropical moist deciduous forest (Grewia-Dalbergia community) of the Western Ghats was studied. Litter fall was observed throughout the year with maximum fall during January and February. Average annual litter production amounted to 14220 kg/ha, of which leaf litter contributed 10754 kg/ha. Grewia tiliifolia being the dominant species in the community it contributed maximum leaflitter (1739 kg/ha) followed by Pterocarpus marsupium (1465 kg/ha), Dalbergia paniculata (1173 kg/ha) and D. latifolia (923 kg/ha). Shrubs and herbs contributed 39% of total leaf litter With regards to nutrients, leaf litter had the highest percentage concentration of nitrogen, phosphorus and potassium. Among the species,Anogeissuslatifolia had the higher concentration of nitrogen (2.7) when compared to other species. On an annual basis 238 kg/ha of N, 9 kg/ha of P and 89 kg/ha of K were returned through litter fall. The litter production as well as nutrients input through litter fall in the present community was much higher than those reported from other communities.

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M. George , G. Varghese

Abstract

Biomass, productivity and nutrient cycling In a Eucalyptus globulus plantation of age 10 years (density 1575) trees/ha) was studied. The total above-ground biomass produced was 76877 kg/ha of which wood contributed 50456 kg/ha and the rest by other components. Roots contributed 18% of above-ground biomass. Chemical analysis revealed that, on an annual basis, out of the 43 kg/ha of N,2.8 kg/ha of P and 36 kg/ha of K retained in the biomass, 19, 1.5,19 kg/ha of N, P and K respectively was accumulated in wood. Thus maximum drain of nutrients occurs through wood harvest and among the nutrients the highest drain occurs for N and K. Litter production in the plantation amounted to 8492 kg/ha, of which leaf litter contributed 3402 kg/ha, twig 3187 kg/ha and bark 1903 kg/ha. With regards to the nutrients return N amounted to 58 kg/ha; P, 4.0 kg/ha and K, 40 kg/ha and leaf litter contributed maximum amount of all nutrients. These results have been compared with other plantation species like E. hybrid, E. grandis, Dolbergia sissoo and Pinus palula. The article also points out the significance of biomass components harvest over complete tree harvest.

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M. George , G. Varghese

Abstract

Dry matter production, nutrients accumulation and nutrients removal through harvest in a 10 year old E. globulus plantation was estimated. The total above- ground biomass amounted to 76.877 kg/ha of which 66% was contributed by wood. Root biomass constituted 18% of AGB. On unit area basis 474 kg/ha of N, 32 kg/ha of P and 386 kg/ha of K was accumulated in the total (agb+ischolar_main) biomass of which 40% to 48% of all nutrients was removed by harvesting wood. The extraction of twigs and bark will cause an additional loss of 9-15% of various nutrients in addition to the loss caused by the removal of leaf which is 7% to 11%. The results emphasise that, necessary safeguards are to be taken to maintain the fertility status of the soils while large area is converted to plantations of E.globulus.

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M. George , G. Varghese

Abstract

Litter production and nutrients in Eucalyptus globulus plantation of age 10 years were studied for a period of one year. A total of 8492 kg/ha of litter was produced of which leaf litter contributed 40% (3402 kg/ha), twig 38% (3187 kg/ha) and bark 22% (1903 kg/ha) With reeards to nutrients. The highest concentration of N, P and K was in leaf. On an annual basis, the total return of nitrogen was 58 kg/ha followed by potassium 40 kg/ha and phosphorus 4.6 kg/ha. Maximum amoust of all the nutrients were returned thorugh litter and lowest through bark.

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S. K. Sharma , K. G. Prasad , M. George , S. B. Singh

Abstract

While various methods are available for collection of soil and vegetation data for further processing, no information is available from South Indian Forest, on the intensity of sampling for their survey, classification and mapping. An area of about 9000 ha in Coimbatore forest division was surveyed and both soil and vegetation data were collected at varying grid distances. The data were grouped, classified and mapped. Chi-square value of heterogeneity increased when the grid length was increased across the contour than along the contour. Considering the time and cost involved in survey, analysis of samples, processing of data and preparation of report, by compromising with accuracy, grid distance of 2km along the contour and 1 km across the contour may be used for forest soil and vegetation survey, classification and mapping.

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M. George , G. Varghese

Abstract

Structural formation of three deciduous forest vegetation communities were studied and profile diagrams were drawn and described. The communities grown at three different locations show differences in species composition, structure, growth parameters, species distribution etc. The area which receives an average annual rainfall of about 1500 mm to 2500 mm carries moist mixed deciduous forests where Terminalia tomentosa and Lagerstroemia microcarpa are the dominant trees, while areas where rainfall is about 750 to 1500 mm, dry deciduous forests with Tectona grandis and Anogeissus latifolia as dominant trees occur. Locations where the rainfall is less than 750 mm Anogeissus latifolia and Acacia chundra dominate.

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K. G. Prasad , S. B. Singh , G. N. Gupta , M. George

Abstract

Investigation on changes in soil properties owing to conversion of natural forests into mixed and teak plantations were carried out. Observations after 40 years of such conversion, indicate higher loss of soil fertility (organic C, P₂0₅ and Mg) under teak plantation than mixed plantation. Initiation of illuviation process was also noted under later. Morphological features, however, remained unaffected. Nonetheless, the study suggests more comprehensive studies on this aspect.

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M. George

Abstract

Biomass production and nutrients accumulation in three ten years old Eucalyptur hybrid plantations located in Tarai Bhabar. Pilibhit and East Dehradun divisions of Uttar Pradesh were estimated. The wood (under bark) production was 93187 kg/ha (992 trees/ha, 98683 kg/ha (1023 trees/ha) and 82804 kg/ha (1133 trees/ha) which formed 69 to 74% of total above ground biomass. Maxium accumulation of N, P, K and Mg was obsened in wood where as that of Ca was in bark. The results indicat that by clear felling ten years old plantations, of the total uptake, 43 to 44% of N, 48 to 50% of P, 31 to 35% of K and 37 to 47% of Mg is removed by wood harvesting alone. Nutrient removal by various biomass components and its implication on soil fertility is discussed.

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S. K. Sharma , M. George , K. G. Pasad

Abstract

The paper deals with the standardisation of quadrat size and recording of vegetation data with special reference to south Indian forests for its classification into communuties and mapping. The data were collected from south Indian dry deciduous, moist deciduous, semi-evergreen and evergreen type of forests. The minimal area for tree quadrat depends on the forest type and varies from 400 m³ for dry and moist deciduous forests to 900 m². For semi-evergreen and evergreen forests. Quadrat size of 9 m² was minimal for shurbs irrespective of forests types. Methods of laying out quadrat for convenient and speedy recording of vegetation data have been described.

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M. George

Abstract

Studies on litter production and nutrient return in three Eucalyptus hybrid plantations of ages 5, 7 and 10 years of East Dehra Dun Division were carried out for one year. A total of 3377 kg /ha, 3801 kg/ha and 6207 kg/ha of litter were produced by these three plantations respectively. Of the total litter, leaf litter contributed between 66%;' to 76%, twigs between 16% to 24% and bark between 5% to 10%. Leaf litter, therefore, contributed the bulk of the litter fall followed by twigs and bark. Considering the nutrients in the various litter components at different ages the concentration of all the nutrients (N, P, K, Ca and Mg) was highest in the leaf followed by twigs and bark, except for Mg which showed a higher concenration in the bark than in the leaves and twigs. The concentration of nutrients in all th litter components at all the three also decreases as Ca, N, K, Mg and P; the highest being that of Ca and N and lowest that of P. The total annual return of nutrients in all the three plantations is highest for Ca (49.2, 42.8 and 73.2 kg/ha respectively for 5, 7 and 10 years ages) followed by N (29.8, 32.1 and 59.2 kg/ha), K (15.0, 17.5 and 30.6 kg/ha), Mg (5.0, 6.1 and 9.3 kg/ha), and lowest for P (1.6, 1.9 and 3.9 kg/ha). The maximum amount of all nutrients is returned through leaf litter and lowest through bark.

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M. George

Abstract

Investigations on nutrients reuturn by stemflow, throughfall rainwater under a Eucalyptus hybrid plantation was carried out for a period of one year. Concentration of nutrients in stemflow and throughfall decreases in the order of K, Ca, Mg, N and P while in the case of rainwater the order was Ca K, Mg, N and P. The highest concentration of all nutrients was in stemflow followed by throughfall and rainwater. On a unit area basis the total return of various nutrients amounted to be 185 kg/ha of K, 18.5 kg/ha of Ca, 4.7 kg/ha Mg, 3.9 kg/ha of N and 0 4 kg/ha of P. These data have been compared with nutrients return throutgh litter fall in a Eucalyptus hybrid plantation and the importance of nutrients return by rain in nutrient cycling studies has been discussed.

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A. Balasundaram , M. George , K. G. Prasad

Abstract

Quadrat study was carried out on regeneration of rosewood (Dalbergia latifolia Roxb.), in the Janmam Forests of Gudalure Forest Division of Coimbatore Circle, Tamil Nadu. This is a mountainous forest tract consisting of moist deciduous, grass-phoenix, and semi-evergreen types of vegetation. More frequency, abundance and density of rosewood ischolar_main suckers were observed in Phoenix- Careya- Dalbergia association (0.67, 8.75,and 5.83 respectively) followed by Olea- Mallotus- Lantena association (0.36, 3.00 and 1.09 respectively), and Cinnamomum- Zizyphus- Dalbergia association (0.40, 2.00 and 0.80 respectively). Suggestions have been made to preserve and protect these young plants of rosewood which have come up naturally and to propagate ischolar_main suckers artificially which will improve the rosewood population in the tract.

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M. George

Abstract

Investigation and interception of precipitation, stemflow and throughfall were carried out for a period of one year in a Eucalyptus hybrid plantation of age 6 years and density 1658 trees/ha in the demonstration Area of F.R.I. & Colleges, New Forest, Dehra Dun. The total stemflow and throughfall over the year accounted for 7.60% (127.2 mm) and 80.75% (13497 mm) of the total rainfall (1671. 7 mm) respectively while only 11.65% (1948 mm) was intercepted by the canopy. The interception loss was 8% to 14% and 19% to 39% of the annual precipitation for rainy season and witer months respectively. The highest interception was recorded in October, the month, which had the lowest rainfall while the lowest interception was recorded in July and August, the months which had the highest rainfall (544.0 mm and 423.7 mm) The average stemflow per tree per year increases with increasing diameter on a unit area basis the amount of stemflow calculated from the sample trees and that of throughfall from sample troughs accounted 1,272.000 litres (kg/ha/year) and 13,497.000 litres (kg/ha/year) respectively. E. hybrid couducts more water as stemflow and throughfall, when compared with other species like sal, teak, chir and khair.

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M. George ¹, V. V. Parthasarathy ¹

Affiliations
1 Technical Information Centre, Electronics and Radar Development Establishment, Bangalore 1, IN

Abstract

Studies the scatter and seepage of documents on Electro-chemistry among 592 periodicals. About J 27 periodicals cany nearly 90 per cent of the documents on the subject. Less than 4 per cent of the documents are published in sources not dealing with Electro-chemistry or its penumbral areas. About 80 per cent of the documents are articles. The highest number of citations (19%) is to the host periodical studied, namely Journal, Electrochemical Society. The highest number of citations in any one volume of the Journal is to the documents published two years earlier. Approximately 40 per cent of the citations in any one volume of the Journal are to documents published during the preceding 5 years, and 69 per cent citations are to documents published during the preceding 10 years.

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