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Effect of grazing and changing climate on vegetation composition of alpine pasture at Tungnath, Garhwal Himalaya was observed. Growth form pattern and phytosociological attributes were analyzed during 1988 under grazed (exposed to extensive grazing) and ungrazed (protected from grazing) conditions. These observations were repeated during 1998. It was observed that number of early growing species and long vegetative growth cycle species had increased at both sites in 1998 in comparison to 1988. Further, some species, viz., Poa alpina, Polygonum spp., Ranunculus hirtellus, Anemone spp., are predominantly found near the timberline-subalpine region. These species are less palatable and were present at both sites with higher dominance (TBC) and niche width in 1998 indicating wide distribution of the species along an altitudinal gradient. These observations indicated the migration of these species towards upper slopes of alpine. Species diversity was also higher after ten years. However, it is clear that climatic changes alone are not responsible for these vegetational shifts. In fact, humaninduced changes are the main reason for habitat destruction and changes in vegetation composition of the alpine region of Garhwal Himalaya. Before final conclusions can be made, long-term studies on vegetation composition and changes are needed, especially in Himalayan region.
Dormancy-breaking and seed germination studies in genus Lilium reveal that the majority of Lilium spp. studied have an underdeveloped embryo at maturity, which grows inside the seed before the radicle emerges. Additionally, the embryo, radicle or cotyledon has a physiological component of dormancy; thus, Lilium seeds have morphophysiological dormancy (MPD). A previous study suggested that seeds of Lilium polyphyllum have MPD but the study did not investigate the development of the embryo, which is one of the main criteria to determine MPD in seeds. To test this hypothesis, we investigated embryo growth and emergence of radicles and epicotyls in seeds over a range of temperatures. At maturity, seeds had underdeveloped embryos which developed fully at warm temperature within 6 weeks. Immediately after embryo growth, radicles also emerged at warm temperatures. However, epicotyls failed to emerge soon after radicle emergence. Epicotyls emerged from >90% seeds with an emerged radicle only after they were subjected to 2 weeks of cold moist stratification. The overall temperature requirements for dormancy-breaking and seed germination indicate a non-deep simple epicotyl MPD in L. polyphyllum.
to study the effect of nine post-harvest treatments viz., fruit dipping in NAA at 100 mg L -1 , gibberellic acid at 100 mg L -1 , salicylic acid at 5 mM L -1 , covering the fruit with perforated polythene and newspaper bag, fruit coating with wax at 60 g L -1 , fruit dipping in maleic hydrazide at 500 mg L -1 , covering of fruit with dry straw and control, on fruit physico-chemical qualities and shelf life of pineapple cv. Giant Kew. Experiment was laid out in complete randomized design with three replications. Study revealed that among the different treatments, fruits treated with GA 3 at 100 mg L -1 showed delayed response of ripening and high shelf life (19.05 days) during storage. At 15 DAS, skin colour remained quarter yellow (average score: 3.2), flesh colour remained more white than yellow (average score: 3), whereas, fruits showed considerably higher amount of TSS (20.41°Brix), TSS : acid ratio (20.21), total sugar (13.67%) and ascorbic acid content (18.49 mg 100 g pulp -1 ) with less weight loss (11.61%) due to this treatment. However, among the other treatments, SA (5.0 mM) performed well in terms of fruit physico-chemical properties and shelf life. SA treated fruits showed less external disease (average score: 1.8) and fruit decay (average score: 2.0) with high juice content (71.63%) and TSS (19.12 °Brix) at 15 DAS along with high shelf life (17.05 days).
Observations on above ground litter decomposition and nutrient release in alpine ecosystem of the Himalaya were carried out. Monthly variation was observed for above ground litter crop and it was higher in the protected sites (PR) when compared with unprotected sites (UNPR). Turnover rate (TR) and time (TT) was also higher in PR sites and it corresponded to maximum net accumulation of standing dead and litter biomass. This resulted into low litter disappearance and therefore, low nutrient fluxes as well. Comparatively, potassium content was a maximum followed by N and OC in above ground crop of litter with significant variation among the sites (P \ 0.001 and 0.005, respectively). It was observed that only 9-12% litter of various categories was decomposed annually at the rate of 0.1-0.13%. Overall, decomposition process was a maximum during active growth season and only 13.2-16.2% of total litter was decomposed during the winter months (December-March). Release of OC and NPK to soil organic matter through the decomposition of various litter types was also observed and the pattern of release was similar to that of disappearance channel. All these parameters are reported and possible reasons are described in the present paper.
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