Land quality and soil organic carbon stocks consequent to land use
change from natural forest to coffee plantation in a hot humid tropical
ecosystem of Western Ghats, South India: Is it restorative enough?
Abstract
Western Ghats, known for its biodiversity, once well covered with dense
forest, has been severely felled for cultivation of coffee, covering an
area of 3.81 lakh ha and production of 3.27 lakh tonnes. To evaluate the
effects of conversion from natural forests to coffee plantation on land
quality, the changes in soil physical and chemical properties and soil
organic carbon stock were assessed in selected hot per-humid, hot moist
sub-humid and hot humid forest and coffee ecosystems of Chikmagalur
district of Karnataka, Wayanad and Idukki districts of Kerala in the
Western Ghats. Sixty sites were studied to understand the soil quality
of which 46 sites were located in coffee plantations and 14 in forests
adjacent to coffee plantations. In this study, six typifying pedons
representing Chikmagalur district of Karnataka, Wayanad and Idukki
districts of Kerala in the Western Ghats are explained by comparing the
existing natural forest with that of coffee plantation ecosystem. The
increase in soil organic carbon stocks (16.32-16.38 kg m-2 in forests to
14.32-19.28 kg m-2 in coffee system), the most reliable indicator of
land quality and other soil properties like clay content, pH,
exchangeable bases, CEC, available nutrients like N, P, Ca, Mg, S, Zn
and Cu in the study area revealed that there was an improvement in land
quality, owing to lesser disturbance and better management in coffee
plantation compared to forests on its conversion which indicates the
restoration of land.