Diversity of fern's

Diversity of fern/ pteridophytes - introduction , history , classification of pteridophytes, diversity of fern in India , about fern , Fern's diversity alpha diversity and beta diversity , explanation of fern through the reproduction example , different varieties of fern.

1. Diversity of Fern’s By- Sneha sahu M.Sc. 3 rd semester in botany

2. Content Introduction History Classification of pteridophytes About Fern’s Diversity of Fern’s Variety of Fern’s

3. Introduction •A pteridophyte is a vascular plant that disperses spores. Because pteridophytes produce neither flowers nor seeds, they are sometimes referred to as "cryptogams", meaning that their means of reproduction is hidden ( Flower or seed). • The term 'Pteridophyta' for ferns was given by Ernst Haeckel. • Pteridophytes (pteron= feather, phyton= plant, i.e. plants with feather like leaves) • There are about 400 genera and about 10,500 species • They were the dominant plant during the Carboniferous Period. • Leaves may be very small ( microphylls ) as in Selaginella or large ( macrophylls ) as in ferns ( Dryopteris ) . • At maturity , leaves become modified as sporophylls and bear sporangia . • One of the important cut foliage and indoor potted plant grown for its attractive foliages is fern.

4. History Pteridophytes have a long geological history on our planet. They are known from as far back as 380 million years. Fossils of pteridophytes have been obtained from rock strata belonging to Silurian and Devonian periods of the Palaeozoic era.As a group, the pteridophytes lie between bryophytes and spermatophytes. Geographically, ferns are most abundant in the tropics. Arctic and Antarctic regions possess few species. On the other hand, a small tropical country such as Costa Rica may have more than 900 species of ferns—about twice as many as are found in all of North America north of Mexico

5. Fern diversity in India India with a highly variable climate has a rich Pteridophyte diversity. There are about thousand species occur in the different parts of India. Western Himalaya and Western Ghats supported pteridophytes species of fern and fern allies in India. Biodiversity conservation is the need of time and hence it has become imperative to develop in-situ and ex- situ conservation methods for the conservation of existing pteridophyte diversity in the area. In- situ conservation methods should be given prominence as it allows the evolution of the species within the natural habitat thus increasing its further diversity

6. Classification of pteridophytes pteridophyta

7. Fern’s • Largest group of extant (living) vascular plants Wide range of habitats (terrestrial, aquatic, arboreal ferns, epiphytic) •Can asexually reproduce by Rhizomes (underground stems) • Dominant Sporophyte stage has true roots, stems, and leaves •Roots and stems underground •Leaves called fronds found above ground and attached to a stem like petiole • Fern is also known as the snake of the plant kingdom • Most ferns are found in New Zealand

8. Diversity of Fern’s Alpha Diversity Alpha diversity refers to the diversity within a particular area or ecosystem and is usually expressed by the number of species in that ecosystem. Pattem of species richness B . Mountains as hot spots of biodiversity • Fern diversity among mountain ranges would vary depending on its elevation, because not all mountain ranges had the same elevation. • It has been observed that fern species have been dependent on humid microhabitats, mild temperatures, in ravines , streams rather than slopes.

9. Conti… Beta Diversity • Beta diversity is the change of plant communities along ecological gradients. Or animal • While these gradients can cover a wide range of spatial , temporal and ecological aspects, studies on the beta diversity of ferns have mostly focused on change in geological substrates and soils as well as elevation. Elevational Gradient Families Aspleniaceae and Dryopteridaceae Found to the lowest to the highest elevation 2. Family Hymenophylleceae Found at low to the middle elevation.

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