Recovery Pattern of Vegetation during Succession Following Slash and Burn Agriculture in Mizoram, North-East India

The recovery of forest after shifting cultivation (locally known as ‘jhum') has multiple complications as observed in various forest types, disturbed regimes, climate conditions and so forth. Rate of recovery and species composition are of major concern to understand the process of succession. The present study was carried out in Champhai district of Mizoram, India with the aim to comprehend the recovery of vegetation at different stages of succession after abandonment. Jhum fields of 5, 10, 15 and 25 fallow ages were located from the satellite imagery and the plot was navigated using GPS. Quadrats were randomly laid within those plots and the plants were enumerated and analysed. The species were contiguously distributed. Ecological indices indicated high diversity and species richness for tree and shrub components but low diversity and species richness for herbaceous component. The number of tree species declined by 5.1% from 5 years fallow to 10 years fallow. However, it increases from 10 years to 15 years fallow by 8.1% and was further enhanced to 32.5% on 25 years fallow. It was also observed that the number of shrub species declined from 5 years to 10 years fallow by 4.9% which worsened to 15.4% on 15 years fallow. Nevertheless, there was a distinct rise in the number of species on the 25 years fallow by 54.6%. Interestingly, the number of herbaceous species was observed to decrease from 5 years to 10 years fallow by 6.8% and further declined by 2.4% and 17.5% on 15 years and 25 years fallow, respectively. Therefore, the percent recovery of tree and shrub species from 5 years to 25 years fallow was 35.9% and 24.4%, respectively, while 25.0% of herb species declined during the same fallow period.