Diversity of Arbuscular Mycorrhizal Fungi in Disturbed and Undisturbed Forests of Karbi Anglong Hills of Assam, India

Destruction of forests for agricultural purposes is a leading cause of forest disturbance and consequently of biodiversity loss. To assess the impact of such forest disturbance on microbial diversity, we investigated the diversity of arbuscular mycorrhizal fungi (AMF) in the rich forests of Karbi Anglong hills of Assam, India. Three forest types viz. undisturbed forests (UF), slash-and-burn field (SBF) and monoculture forest (MF) were selected. A total of 21 isolates of AMF belonging to 4 genera were extracted and identified from rhizospheric soil. ‘Species forming glomoid spores’ comprised Glomus sensu lato, Rhizophagus and Claroideoglomus were the dominant genera in all the three sites. Spore density was highest in UF and lowest in MF. Shannon–Wiener index of diversity and Simpson’s diversity index were almost similar in UF and SBF. Our results show that natural undisturbed forest and slash-and-burn field contained similar and a high AMF diversity compared to monoculture forest. The AMF diversity is not significantly affected by the slash-and-burn agricultural land use practices practised by the local tribes and, therefore, could be a component of a tropical forest ‘conservation–agriculture matrix’.