Impact of Coal Mining on Vegetation: A Case Study in Jaintia Hills ...

IMPACT OF COAL MINING ON VEGETATION: A CASE STUDY IN JAINTIA HILLS DISTRICT OF MEGHALAYA, INDIANumber <strong>of</strong> quadrats <strong>of</strong> occurrence <strong>of</strong> a speciesFrequency (%) = ------------------------------------------------------------ x 100Total number <strong>of</strong> quadrats studiedTotal number <strong>of</strong> individuals <strong>of</strong> a speciesDensity = ----------------------------------------------------Total number <strong>of</strong> quadrats studiedBasal cover = Density x average basal area <strong>of</strong> individuals <strong>of</strong> a speciesBasal area was calculated based on the measurement <strong>of</strong> CHB at 1.37m heights.Number <strong>of</strong> individuals <strong>of</strong> a speciesAbundance = -------------------------------------------------------------Number <strong>of</strong> quadrats <strong>of</strong> occurrence <strong>of</strong> the speciesSimpson Dominance Index (1949) = (n i / N) 2where, n i = importance value indexN = total importance value <strong>of</strong> all speciesThe distribution pattern <strong>of</strong> the species was studied by using Whitford’s index (Whitford 1948).Abundance (A)Whitford’ s index = ----------------------;Frequency (F)if A/F ratio:< 0.025 :Regular distribution0.025 - 0.05 :Random distribution> 0.05 :Contagious or clumped distributionShannon-Weaver index <strong>of</strong> general diversity was calculated by using the formulaH = - ∑ (n i / N) ln (n i / N)where, H = Shannon-Weaver indexn i = importance value indexN = total importance value <strong>of</strong> all species27