Species Composition And Some Physico-Chemical Properties Of An Age Series Of Overburden Dumps In Sukinda Chromite Mines, Jajpur, Odisha, India

Abstract

Opencast mining replaces natural vegetation of an area with huge quantities of overburden dumps called mine spoils. Natural plant succession on these spoils cause changes in physico-chemical characteristic of soil leading to restoration and conservation of biodiversity. The present study, which was carried out in the Sukinda chromite mining region of the Jajpur district in Odisha, focused on vegetation composition and soil physico-chemical properties of an age series overburden dumps (OB) ranged in age from 1 to 18 years formed as a result of open cast mining activity of Saruabil and Tata steel chromite mines that were operated in this region.

Over the course of two-year reconnaissance survey, a total of 117 herb species of 41 families and 65 tree species of 25 families were identified from eight sites of the study area . Out of the eight sites, five were selected from the Tata Steel Mines with plantation ages of 1, 2, 4, 13, and 15 years, and three from the Saruabil Mines with plantation ages of 3, 14, and 18 years.

The sites were named based on the age of the plantations; for example, D1 was given to the location of a plantation that was one year old and so on.

At all the selected study sites, vegetation analysis was done for the planted tree species. The number of species were not demonstrated any particular pattern with the age of the sites. C. dactylon, one of the herb species, was present on each aspect of every site. M. pudica was present on every aspect of all sites except south of D5 and D7. P. foetida and R. quinqennalaris were observed on only east and south aspects of D6 and south aspect of D8, respectively.

However, species number of herb species was generally higher with increased number of tree species. The number of herb species recorded at different study sites were in the order of D4 (65)>D1 ( 62) ,D8 (62)>D2 (58)> D6 ( 56) ,D7 (56) > D5 (54) and D3 (40). Soil analysis results indicated that the clay content was less than 28% at all the sites. The soil was moderately acidic. pH was less than 6 at D8 and for other sites it varied from 6.1 to 6.5.

The trend of OC content at different sites was in the order of D8>D6>D7>D2>D1>D5>D4 and ranged between 0.695 to 0.11%. N content varied between 62.5 and 226.25 kg ha^-1. N content was maximum at dump 8 (D8) and minimum at D4. P content ranged between 5.45 and 9.58 kg ha^-1 across all the sites with a highest value at D8 and lowest at D2 and D5. K was found in the range of

37.63 and 349.44 kg ha^-1 with maximum at D6 and D8, and minimum at D1 and D3