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.

Full Text

     

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.

Full Text

     

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.

Full Text

     

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.

Full Text

     

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.

Full Text