The
studies on diatom assemblages came into exit during the early 19th century (Gregory,
1854). Extensive studies on the diatom assemblages began during the 20the
centuries when the Kolkwitz and Marsson (1908) give the autoecological concept
of the indicator species further which improve latter by Patrick et al. (1954)
and gave the synecological approach to the assessing stream condition by
biological means. Such approach places the emphasis on the study of association
or communities of organism rather than upon the presence or absent of certain
species. Most of the studies based on synecology reflect the two basic ideas
concerning community structure which were set forth by Thienemann (1939), The
first of these ideas is that the more variable the conditions of life in a
place, the greater the number of species in the community. The second concept
is that the further the conditions of life are removed from the optimum for the
majority of species, the poorer in numbers of species becomes the community but
the remaining species tend to become more numerous in terms of individuals.
Diatom assemblages was conducted in different
regions of the world. (....Ref...). However, the studies were concerned largely
on the distribution of diatoms in various aquatic habitats in different period
and scale from the various part of the world (Riffe...). The studies on diatom
community structure came in to interest when the diatoms were used as
biological indicators in the 20th century. Documentation on diatom community
structure has been established by ... in .. for the water quality monitoring. The
studies on community structure were continued and carried out in different
region of the world from various habitats. However, in most of the studies diatom
assemblages were studied on the rivers, streams, lake and ponds. Diatom
assemblages were intensely studied worldwide from various water bodies concerning
various aspects, as assessing environmental conditions in river and streams
with diatoms (Patrick 1973; Stevenson and Love, 1986; Round, 1991; Whitton et
al. 1991; Coste et al. 1991; Whitten and Kelly, 1995; Rosen, 1995; Love and
Pan, 1996....)
the
approach was diatom community structure was studied with large aspect to the
water quality monitoring throughout the world wide (Jorgensen, 1957;
Christensen and Reimer, 1963; John & Jack, 1978; Olive and Price, 1978; Lamb
and Lowe 1981, 1987; Blinn, 1993; Charles, 1985; Nautiyal and Singh, 1996; Chiang
et al, 1997; Nascimento et al. 1998; Vibaste, 2001; Potapova and Patrick, 2002;
Rimet et al. 2004; Soininen and Eloranta, 2004; Leira and Sabater, 2005; Walker
and Pan 2006; Chathain and Harrington, 2008; Soininen and Weckstrom, 2009;
Leira and Kwandrans, 2007; Sonmez and Caglar, 2011; Zhang et al. 2011; Kivrak
and Uygun, 2012; Nautiyal and Mishra, 2013; Stanish et al. 2013; Vázquez and
Caballero, 2013; Bere and Mangadze, 2014; Singh et al. 2014; Darling, 2015). Many investigations have been
made in to the diatom community structure with reference to spatial and temporal
variations (Vaultoburg and Pederson, 1994; Pan et al. 2000; Xiuning et al.
2012; Soininen et al. 2004; Mc Clatchie et al. 2015). Other studies with
various prospects were as diatom community structure in relation to seasonal
changes (Ohtsuka, 1996; Nı´Chatháin and Harrington 2008 ); diatom community
with respect to land use (Mylvaganam and John, 1998); diatom community with changes
in altitude (Nautiyal, 1998); diatom assemblages in response to light (Ikeya
2001, Lange et al 2011,); diatom assemblages
as indicators of timber harvest (Naymik 2005), diatom community in
relation to the host (Jewaka et al 2013); diatom community structure from the
various fish gut (Bešta et al 2015), from the ship hulls (Hunsucker et al
2015), from riparian soil (Vachta et al 2012)
and diatom community from the artificial substrate (Dalu et al. 2014).
All
the above studies on the diatom community were not deal with the habitat
preference. There were a little studied which deals on the diatom community
structure in relation to the various habitats structure from the different part
of the world. In the context of habitat diatom assemblages were investigated in
both, micro-habitats such as epilithic, epipelic, epiphyitic, etc. and habitats
such as river, stream, pond, lake, spring, canal etc.
Some
researchers have found distinct associations of benthic diatom on different
substrate in rivers, lake, streams indicating specific habitat preferences (Reavie
and Smol, 1997; Round, 1993). From the microhabitats Nautiyal et al. (1996)
investigated the community structure in relation to substrate (epilithic and
epiphytic) and flow condition of the Himalaya river Alaknanda. Alkananda et al. (2011) studied the
microhabitat influence on the diatom distributional pattern in the lake from
south India. Kopalova et al. (2014)
studies the moss inhabiting diatoms from the maritime Antarctic island.
However studies on the diatom
assemblages with respective to the habitat were scare. Little studies on the
diatom in relation to habitat were studied from the various parts of the world.
De Vijver and Beyens (1996) studied the diatom communities from the various
water bodies in Stromness Bay area of South Georgia. De Vijver et al. (2001) investigated
the habitat preferences in freshwater diatom communities from the different
water bodies in sub-Antarctic Iles Kerguelen. Baier T (2005) studied the diatom
communities amongst the types of wetland habitats of the south-western New
Zealand, El-Awamri et al. (2005) investigated diatom flora from different
aquatic habitats such as river, irrigation canals, drains, springs, pools,
ditches and fountains in the Greater cairo (Egypt). Bere T (2010) investigated diatom community
structure and habitat preferences along the urban pollution gradient in
Monjolinho river of Brazil, Falasco and Bona (2011) studied diatom communities
colonizing in different habitats (river, spring, and bog) of the Valasco Valley
(in Maritime Alps Natural Park). Kova’cs et al. (2013) studied the diatom
assemblages in different stream order from the Hungary.
In India such diatom community in relation to
habitat preference is still lacking however large numbers of studies on diatom
community structure with various aspects from the river, stream and pond
separately have been investigated (Nautiyal 1997, 2001, Nautiyal et al. 1996 a, 1997, 1999, 2000, Nautiyal
et al. 2004, Ormerod
et al. 1994, Jüttner et al. 1996, Ormerod et al. 1996, Rothfritz et al. 1997, Cantonati
et al. 2001, Jüttner and Cox 2001).