K. S. Shashidhar , A. N. Arun Kumar

Abstract

Of the diverse flora and fauna in an ecosystem, epiphytes in general and orchids in particular have a vital role to play in Mutualism. By virtue of their sensitivity to the changes in the climate they provide a forewarning about the impending damages due to these changes and act as bioindicators. Epiphytes constitute ten per cent of the higher plants in tropical forest ecosystem. They provide a niche to many flora and fauna by complimenting the life supporting systems and play a vital role in rainforest hydrology and mineral cycle. Orchids as a group of epiphytes with 900 genera and 30,000 species are sensitive to variations in microclimate and are known as keystone species in the forest ecosystem. Interrelationship of orchids with various biotas in the ecosystem is well documented. Orchid's dependence on other biota and their co existence for several important processes such as pollination, dispersal and sustenance is well known. Natural and man made changes have influenced the climate and in turn the ecosystem through several of its parameters such as rainfall and temperature. One of the direct effects of this is, change in the plant structure and composition. The changes in the climate have also affected sensitive events such as flowering and pollination. This has forced the plant species to shift to more congenial climate for its survival and eventually affecting the coexisting biota. Therefore, before planning any conservation strategies the reasons for threat (especially manmade) to these indicator species must be understood. We believe that, ideal long term orchid conservation approaches must lay emphasis not only on the species but also on its fragile habitat.

Keywords

Epiphytes, Orchids, Bioindicators, Climate Change, Conservation

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K. C. Chauhan , A. N. Arun Kumar

Abstract

Seeds collected from four different classes (D₁=<20.50 cm; D₂=20.51-30.50 cm; D₃= 30.51- 40.50 cm and D₄ =>40.51 cm) at six harvesting dates (Viz; C₁ = 30th Dec., C₂ = 15th Jan., C₃ = 30th Jan., C₄ = 15th. Feb., C₅ = 1st March and C₆ = 15th March) gave significant differences for different bio-chemical constituents viz; total, reducing, non-reducing sugars, total phenols, starch, total amino acids and soluble proteins. The combinations ofD₁C₆, D₂C₆, D₃C₆, and D₄C₆ registered the highest total and non-reducing sugars in their respective diameter classes. Whereas, harvesting date C₃ (30th Jan.) in all diameter classes recorded maximum content of starch, total phenols, soluble proteins and total amino acids. The present study suggested that C₃ (30th Jan.) was the best harvesting date irrespective of diameter classes in this species.

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