A rapid assessment on the status and distribution patterns of coarse woody debris （CWD） was conducted by laying five curvilinear transects （transects A, B, C, D and E; major trails）, along an altitudinal gradient ...A rapid assessment on the status and distribution patterns of coarse woody debris （CWD） was conducted by laying five curvilinear transects （transects A, B, C, D and E; major trails）, along an altitudinal gradient starting from 900 to 2 600 m, in three major watersheds （Charigad, Dogarhigad and upper Gosigad） of Goriganga catchment in Askot Wildlife Sanctuary, India. At every 100 m rise in altitude a hectare plot （100 m x 100 m） was selected. Results showed that the percentage contribution by different succession phases was in the decreasing order： phase I 〉 phase II 〉 phase IV 〉 phase III for snags, and phase III〉 phase II 〉 phase IV 〉 phase I for logs. Snag density in chir pine forest was high in transect A （11 snags＇ha^-1） at 1 500 m, and the value in rianj oak forest was high in transect B （10 snags.ha-l） at 2 300 m. The total available mass of snags and logs in chit pine forest was 13.9 t, of which snags mass accounted for 41% of the total mass and logs mass for 59%. While the total value was 5.6 t in rianj oak forest, of which snags and logs accounted for 60% and 40% of the total mass, respectively. Moreover, the presence of CWD in the study area if not harvested, would provide a great opportunity to the orchids in future to flourish by providing protection. The high densities of snags and logs in chir pine forest at mid-altitudinal zone led to less species richness and lower density of ground flora as the zone receives more light, accompanying with lower soil moisture, and thus only the dominant species occupy the habitat.展开更多
The chemical and petrological correlation of metamorphic nappes and klippes overlying the Proterozoic sedimentary units in the Kumaun Himalaya is still debated. The Ramgarh and Almora gneisses, not previously distingu...The chemical and petrological correlation of metamorphic nappes and klippes overlying the Proterozoic sedimentary units in the Kumaun Himalaya is still debated. The Ramgarh and Almora gneisses, not previously distinguished in the Askot Klippe, show distinct field, petrological and chemical signatures markedly similar to the tectonostratigraphic disposition of the Almora Nappe. A negative Eu anomaly in the Ramgarh granitic gneisses indicates lesser plagioclase fractionation while the Eu anomaly in the Almora pelitic gneisses is likely to have been controlled by feldspar crystallization in restites. During the anatexis at > 776°C temperature and >6.6 kbar pressure, the melt moved slightly away to its crystallization sites. The Rb/Sr ratio ?0.54 and Nb ?10 ppm is consistent with the granodioritic composition. The negative Sr anomaly in the underlying Ramgarh granitic gneisses indicates a distinct mantle derived source/plagioclase fractionation with a notable correspondence to other late orogenic granites, particularly the basement Ulleri gneisses from the Nepal Himalaya. Ramgarh gneisses plot in the late-and post-COLG field. The Askot ensemble is likely to be the tectonometamorphically reworked basement, viz. the Ramgarh Group along with its metapelitic cover o f the Almora Group, together comprising southward thrust remnants of the leading edge of the Indian Plate that collided with Tibet during the Tertiary Himalayan orogeny.展开更多
A rapid assessment on the status and distribution patterns of coarse woody debris (CWD) was conducted by laying five curvilinear transects (transects A, B, C, D and E; major trails), along an altitudinal gradient star...A rapid assessment on the status and distribution patterns of coarse woody debris (CWD) was conducted by laying five curvilinear transects (transects A, B, C, D and E; major trails), along an altitudinal gradient starting from 900 to 2 600 m, in three major watersheds (Charigad, Dogarhigad and upper Gosigad) of Goriganga catchment in Askot Wildlife Sanctuary, India. At every 100 m rise in altitude a hectare plot (100 m x 100 m) was selected. Results showed that the percentage contribution by different succession phases was in the decreasing order: phase I > phase II > phase IV > phase III for snags, and phase III > phase II > phase IV > phase I for logs. Snag density in chir pine forest was high in transect A (11 snags·ha-1) at 1 500 m, and the value in rianj oak forest was high in transect B (10 snags·ha-1) at 2 300 m. The total available mass of snags and logs in chir pine forest was 13.9 t, of which snags mass accounted for 41% of the total mass and logs mass for 59%. While the total value was 5.6 t in rianj oak forest, of which snags and logs accounted for 60% and 40% of the total mass, respectively. Moreover, the presence of CWD in the study area if not harvested, would provide a great opportunity to the orchids in future to flourish by providing protection. The high densities of snags and logs in chir pine forest at mid-altitudinal zone led to less species richness and lower density of ground flora as the zone receives more light, accompanying with lower soil moisture, and thus only the dominant species occupy the habitat.展开更多
文摘A rapid assessment on the status and distribution patterns of coarse woody debris （CWD） was conducted by laying five curvilinear transects （transects A, B, C, D and E; major trails）, along an altitudinal gradient starting from 900 to 2 600 m, in three major watersheds （Charigad, Dogarhigad and upper Gosigad） of Goriganga catchment in Askot Wildlife Sanctuary, India. At every 100 m rise in altitude a hectare plot （100 m x 100 m） was selected. Results showed that the percentage contribution by different succession phases was in the decreasing order： phase I 〉 phase II 〉 phase IV 〉 phase III for snags, and phase III〉 phase II 〉 phase IV 〉 phase I for logs. Snag density in chir pine forest was high in transect A （11 snags＇ha^-1） at 1 500 m, and the value in rianj oak forest was high in transect B （10 snags.ha-l） at 2 300 m. The total available mass of snags and logs in chit pine forest was 13.9 t, of which snags mass accounted for 41% of the total mass and logs mass for 59%. While the total value was 5.6 t in rianj oak forest, of which snags and logs accounted for 60% and 40% of the total mass, respectively. Moreover, the presence of CWD in the study area if not harvested, would provide a great opportunity to the orchids in future to flourish by providing protection. The high densities of snags and logs in chir pine forest at mid-altitudinal zone led to less species richness and lower density of ground flora as the zone receives more light, accompanying with lower soil moisture, and thus only the dominant species occupy the habitat.
基金the financial support from the UGC CAS-I & II grantDSTs New Delhi for financial assistance to MJ. BPD
文摘The chemical and petrological correlation of metamorphic nappes and klippes overlying the Proterozoic sedimentary units in the Kumaun Himalaya is still debated. The Ramgarh and Almora gneisses, not previously distinguished in the Askot Klippe, show distinct field, petrological and chemical signatures markedly similar to the tectonostratigraphic disposition of the Almora Nappe. A negative Eu anomaly in the Ramgarh granitic gneisses indicates lesser plagioclase fractionation while the Eu anomaly in the Almora pelitic gneisses is likely to have been controlled by feldspar crystallization in restites. During the anatexis at > 776°C temperature and >6.6 kbar pressure, the melt moved slightly away to its crystallization sites. The Rb/Sr ratio ?0.54 and Nb ?10 ppm is consistent with the granodioritic composition. The negative Sr anomaly in the underlying Ramgarh granitic gneisses indicates a distinct mantle derived source/plagioclase fractionation with a notable correspondence to other late orogenic granites, particularly the basement Ulleri gneisses from the Nepal Himalaya. Ramgarh gneisses plot in the late-and post-COLG field. The Askot ensemble is likely to be the tectonometamorphically reworked basement, viz. the Ramgarh Group along with its metapelitic cover o f the Almora Group, together comprising southward thrust remnants of the leading edge of the Indian Plate that collided with Tibet during the Tertiary Himalayan orogeny.
文摘A rapid assessment on the status and distribution patterns of coarse woody debris (CWD) was conducted by laying five curvilinear transects (transects A, B, C, D and E; major trails), along an altitudinal gradient starting from 900 to 2 600 m, in three major watersheds (Charigad, Dogarhigad and upper Gosigad) of Goriganga catchment in Askot Wildlife Sanctuary, India. At every 100 m rise in altitude a hectare plot (100 m x 100 m) was selected. Results showed that the percentage contribution by different succession phases was in the decreasing order: phase I > phase II > phase IV > phase III for snags, and phase III > phase II > phase IV > phase I for logs. Snag density in chir pine forest was high in transect A (11 snags·ha-1) at 1 500 m, and the value in rianj oak forest was high in transect B (10 snags·ha-1) at 2 300 m. The total available mass of snags and logs in chir pine forest was 13.9 t, of which snags mass accounted for 41% of the total mass and logs mass for 59%. While the total value was 5.6 t in rianj oak forest, of which snags and logs accounted for 60% and 40% of the total mass, respectively. Moreover, the presence of CWD in the study area if not harvested, would provide a great opportunity to the orchids in future to flourish by providing protection. The high densities of snags and logs in chir pine forest at mid-altitudinal zone led to less species richness and lower density of ground flora as the zone receives more light, accompanying with lower soil moisture, and thus only the dominant species occupy the habitat.
