Diversity of soil macroarthropods in shifting cultivation and forest ecosystem of Mizoram, Northeast India

Abstract

Soil organisms are an integral part of agricultural ecosystems and are essential for the maintenance of healthy productive soils. Little is known about soil arthropods assemblages in shifting cultivation system. Therefore, we compared the diversity of soil macroarthropods in shifting cultivation (EXPTL) system and its adjacent natural forest (CTRL) ecosystem in Mizoram, northeast India and assessed the impact of shifting cultivation on the diversity. The study was conducted from 2013 to 2015, and the period was divided as pre-cultivation, cultivation and post-cultivation phases. Traditional shifting cultivation was practised in EXPTL site in the year 2014. Sampling was done by handpicking and digging from a quadrat (25×25×30 cm) located at least 10 m apart at monthly intervals. Specimens were preserved in 4% formalin and were identified up to the lowest possible taxa. A total of 97 taxa of arthropods belonging to five classes were recorded. 88 taxa and 48 taxa were recorded in CTRL and EXPTL respectively. Order-wise Shannon diversity index was significantly higher (p < .001) in CTRL as compared to EXPTL site. There were significant differences in both cultivation (p <.001) and post-cultivation (p <.001) phases between CTRL and EXPTL sites. There was a significant effect of shifting cultivation on the diversity of soil macroarthropods at the p <.05 level for the three cultivation phases in EXPTL site. Therefore, it was concluded that shifting cultivation system negatively affected soil macroarthropod diversity at least for a short duration. This study provided the first baseline data of soil macroarthropod diversity and its interaction with land-use system from Mizoram, northeast India.