S. C. Agarwal , M. S. Jolly , A. K. Sinha

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S. C. Agarwal

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S. C. Agarwal , B. D. Patil

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Increasing demand for raw material for the paper industry has focussed attention on the immense resources locked up in Fir (Abies pindrow and A. webbiana) and Spruce (Picea morinda) forests. There are numerous difficulties in the proper exploitation of these forests, viz., absence of motorable roads and other means of communication, occurrence of black heart-wood which makes the timber liable to sink while being floated down and inadequate natural regeneration. The absence of adequate natural regeneration in these forests has drawn the attention of forest officers for a long time. Various factors responsible for the inadequacy of regeneration are discussed. It has also been noted that silver fir and spruce seedlings are shade demanders in early stages. Reproduction of both occurs plentifully at lower elevations under broad leaved trees. A large number of exotic and indigenous species ace under trial as nurse crops, e.g., Populus monolifera, P. generosa , P . ciliata, Aesculus indica, Prunus padus, Fraxinus excelsior, Thuja plicata, Larix europea and L. leptolepis, Cupressus torulosa and C.obtusa. The junior author while touring in the U.S.A. observed that aspen (Populus tremuloides) acted as a nurse crop in the regeneration of spruce. It is suggested that further work on the role of broad leaved associates may be taken up. Aspen seems to be a very promising nurse crop and is worth trial.

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S. C. Agarwal , N. D. Rege

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Factors affecting soil erosion like state of soil, its fertility, degree of slope, intensity of rainfall etc., are essential for consideration while planning soil conservation measures. But no amount of soil Conservation measures are fully effective without planning for adequate vegetative cover. The vegetative cover reduces run off and checks soil loss by interception, addition of organic matter to the soil thus improving the structure of the soil affecting porosity and infiltration -and even affording mechanical obstruction to the moving soil particles. The article deals with some trends seen in the studies carried out for determining the effectiveness of different covers in controlling run-off and soil loss and their effectiveness in changing porosity, infiltration etc. through addition of organic matter to the soil.

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S. C. Agarwal , S. Chinnamani , N. D. Rege

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Extensive plantations of Eucalyptus globulus and Acacia mollissima have been taken up in the Nilgiris and Kodaikanal as a planned Forestry measure. Experiments laid down at the Central Soil Conservation Research Station have indicated that Eucalyptus globulus even at an espacement of 6'× 6' permits a fairly heavy soil loss, even though the leaf litter was allowed to accumulate. From the fourth year onwards the soil loss was not experienced at this espacement. It is seen that in bigger and older plantations of bluegum the leaf is invariably collected for oil, the humus is poor and very often rills and gullies appear. Moreover this species is lopped very heavily for oil.

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S. C. Agarwal

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Forests require a particular combination of ecological conditions for their proper development. This hypothesis is true even in the case of the grassland communities. It is, however, believed that the environmental conditions required for the development of a particular grassland type are not so specific as in the case of forests. Thus, a grassland type may run across a number of varying forest types. This distribution becomes specific only if the edaphic conditions are overwhelmingly operative and biotic influences are too rigorous. Thus, a grassland type may co-exist with a forest type if the latter is conditioned by edaphic and biotic influences. Champian's forest types have been made use of while discussing the grassland types.

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S. C. Agarwal

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Grassland Communities occurring in Dry Tropical Forests are described and discussed. The three grassland types already discussed under Moist Tropical Forests also appear in Dry Tropical Forests, but here they develop luxuriantly and express their potential to the best extent due to lesser competetion from shrub growth. Inordinate biotic influence, however, may give a set back.

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S. C. Agarwal , U. S. Madan , S. Chinnamani , N. D. Rege

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Ecological studies under different associations existing in the Nilgiris have been taken up with a view to determine the trends of succession under prevailing conditions and possible introduction of secondary succession as an effective means of Soil Conservation. The studies so far carried out have given some very interesting information. When shola forests are cleared herbs like bracken and Hypericum mysorense come up along with members of Compositae and Leguminosae. If the area has been infested with Cytisus scoparius, Symplocos spicata is seen to be the first tree species to appear. In some places Rhododendron nilagirica comes first in the grasslands. Amongst the grasses the first to appear are Eragrostis spp., Setaria glauca, Digitaria spp., Bothriochloa pertusa followed by either Chrysopogon zeylanicus or Pennisetum clandestinum. Both of these are subsequently replaced by Arundinella or Themeda spp. This replacement of P. clandestinum may prove to be very useful with the help of Arundinella spp. The former is very aggressive and is not liked by local cultivators as it is an effective cover for harbouring rats which spoil the potato crop. The studies are being continued.

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S. C. Agarwal

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The Chakrata forest division, locally known as Jaunsar Bawar, consists of mountainous region with elevations varying from 1530' to 10,905'. It can be divided into four zones--(1) Subtropical zone having mostly the plains grasses like Dichanthium annulatum, Bothriochloa pertusa, Chrysopogon montanus, C. gryllus, Cymbopogon martini, C. jwarancusa, Heteropogon contortus, Ergrostis viscosa, Cynodon dactylon, Chloris montana, C. incompleta, Sporobolus pallidus, Eragrostiella nordioides, Digitaria marginata, D. longiflora along with subtropical grasses like Arundinella setosa and Themada anathera, (2) Temperate-chir zone having generally the sub-tropical grasses like Themeda anathera and Arundinella setosa forming a dominant stand and have an association of the above mentioned plains grasses, (3) Subalpine -deodar zone which is really a transition zone for the grass flora. At lower elevations and warmer aspects the subtropical grasses like Themada anathera and Arundinella setosa associated with some of the plains grasses as seen in the chir zone. But in addition some of the alpine grasses like Argostis spp., Festuca spp., Bromus etc., make their appearance. As the elevation increases the preponderance of the alpine grasses increases and after 8000' elevation they form the dominant stand, (4) The Alpine zone has the alpine association of grasses like Festuca rubra, F. bromoides, F. sibirica, Dactylis glomerata, Agropyron semicostatum, Agrostis spp., Arthraxon species, Avena and Bromus species etc. Management plans for the regions have been suggested.

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