• J S Singh

      Articles written in Proceedings – Plant Sciences

    • Quantitative profile structure of certain forests in the Kumaun Himalaya

      A K Saxena J S Singh

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      The structure of forests occurring within the north-western catchment of the river Gola in Kumaun Himalaya is quantitatively described. All the forestt indicated a total of four strata; two upper strata represented by trees, the third stratum represented mainly by shrubs, and the fourth of herbs. The tree heighs of theA2 (top most) stratum decreased with an increase in altitude. On the other hand, the proportion of trees devoted to the canopy in theA1 andA2 strata increased with an increase in altitude. In all forests, the crowns of theA1 andA2 strata were more deep than wide. In general, the shrub layer in three oak forests was comparatively dense and the crowns of the shrubs overlapped with each other. The canopy index, a relative measure of canopy coverage, of tree and shrub layers was maximum forQuercus floribunda forest and minimum forPinus roxburghii forest. Further, the cooler aspects developed a greater canopy index for these layers as compared to the warmer aspects. Oak forests exhibited a poor development of their herb layers. The trees in theQuercus lanuginosa forest weere more stable, while inPinus roxburghii forest they were specially susceptible to wind effect. In general the warmer aspects had more stable trees, while the cooler aspects showed a lower tree stability. The different forest types, presently studied, could be graded, as follows, in a decreasing order of potential for soil protection:Quercus floribunda > Quercus leucotrichophora > Quercus lanuginosa > mixed >Pinus roxburghii.

    • Influence of clipping and water stress on growth performance and nutrient value of four range grasses

      Hema Pande J S Singh

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      The paper examines the effect of water stress and clipping treatments on growth behaviour and nutrient value of 4 grasses, viz.,Lolium perenne, Poa pratensis (both C3 plants),Chloris gayana andPanicum coloratum (both C4 plants).

      Biomass, net production, relative growth rates were affected more markedly and adversely in the two C4 species due to water stress. The effect of clipping varied with species and was generally more marked and adverse in two C4 species. The C3 plants developed higher R:S ratio under water stress. Water stress resulted in a greater decline of total non-structural carbohydrate and protein content in the two C4 species. Clipping affected adversely the nonstructural carbohydrate content and again the effect was more marked in the two C4 species. On the other hand, protein content in shoots of all plants increased due to clipping.

    • Structure and function of the Central Himalayan oak forests

      S P Singh J S Singh

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      Oak (Quercus spp.) forests represent the climax evergreen vegetation between 1000–3600 m in the Central Himalaya. Shrub layer is well developed in these forests and phanerophytes prevail (50–60%). Though one oak species mixes frequently with other oak species, or conifers, the single-species dominance is quite common. All the oak forests are vulnerable to fire. They support a great variety of wildlife. Coppicing subsequent to cutting is well developed in all oak species and helps them in regeneration. However, because of severe biotic stress oaks are failing to regenerate in forest stands. The forest biomass ranges between 294–787 t ha−1 and the net primary productivity generally between 16–21 t ha−1 yr−1. Oak forests store a large proportion of their nutrients in biomass component. Leaves are nutrient-rich and decompose rapidly. Evergreen woody species with concentrated summer leaf drop prevail in oak forests. The seasonality of the ecosystem activities seem to be influenced by the monsoon pattern of rainfall. Though the recovery is rapid after the forest destruction, because of continuous and severe biotic stress, oaks are being replaced with other communities.

    • Pigment concentration of ten bryophytes from Nainital, Kumaun Himalayas

      N Pande J S Singh

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      The chlorophylls, carotenoids and their ratios were determined in 6 liverworts and 4 mosses of Nainital, Kumaun Himalaya. The amount of chlorophylls and carotenoids was higher in liverworts except forStephensoniella brevipedunculata compared to mosses. Liverworts studied occurred in shady habitats, whereas the mosses occurred in open situations. The chlorophylla/b ratios were less than 1·5. This is a response of bryophytes to low light environments. The chlorophyll/carotenoid ratio did not show any remarkable difference among liverworts and mosses, as the study was carried out during the rainy season—the luxuriant growth period of bryophytes.

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