A Review on Bryophytes as Key Bio-indicators to Monitor Heavy Metals in the Atmosphere

Abstract

Bryophytes are one of the simplest autotrophic cryptogams invading land and characterized either by simple thalloid or erect habit lacking true leaves, root and stem within the plant body. Although they are ubiquitous in distribution, yet becomes sensitive to certain environmental conditions that can be natural or induced due to anthropogenic activity. Due to their versatile tolerance and resistance capability they can be categorically used as potential bioindicators for monitoring pollution. Bryophytes can be utilized as ‘environmental specimen bank’ due to their unique capacity of indicating the presence of metal and their concentration gradient in the substratum. Apart from their utility in pharmaceutical products, horticulture, household purposes they are also ecologically important. As multidimensional applications of the flora are being increasingly standardized universally, their potential in the biomapping of atmospheric pollution as well as ecological biodegradation is also enormous. Currently, a change in global climate is intensified that affected Earth’s biomes and vegetation zones redistribution. At higher altitudes, this alteration is more promising with rapid consequences. Elevated temperatures are expected to produce a drier environment that affect site water balance and cause shifts in the distribution of ecosystems on a universal scale. These effects are rather evident in such ecosystems as peatlands which are sensitive to both climate and water level fluctuations. Decrease in epiphytic bryophytes because of gaseous and particulate pollutants as well as the greenhouse gases is also a serious problem. Besides this, very specific and unique responses are generated by the bryophytes; studies have proven that they act as potential monitoring bio-agents for heavy metal pollution. In the present paper, an attempt is done to do a comprehensive study on bryophytes that reflects their role as promising indicators in monitoring pollution.