Diversity, ecology and biogeography of the family polyporaceae along an altitudinal gradient in forests of nagaland

Chuzho, K. and Dkhar, M.S.

Studies on diversity, ecology and geographical distribution of the family Polyporaceaewere carried out in 8 forest stands of Nagaland along an altitudinal gradient for two successive years (January 2015 to December 2016). Both quadrate and transect methods were followed for sampling Polyporaceae members. A total of 37 Polyporaceaespecies were identified. The results showed that the distribution of wood-rotting Polyporaceaespecies depend on different altitudinal zones, decay stages and availability of substrata. The occurrence of Polyporaceaespecies showed an increasing trend from an altitude of 221meters above sea level (msl) to 890msl, thereafter decreased with increase in altitude. The resultant correlation is of negative type. Ordination of species and environmental variables with canonical correspondence analysis (CCA) indicate that at lower altitudes, temperature was the major factor whereas, at higher altitudes, light intensity and relative humidity were the major factors for determining the occurrence of Polyporaceae members. Logs, twigs and wood decay stage III provided essential habitat for the formation of sporocarps of majority of the species. Shannon’s diversity index (H') was highest in site 3 (Alt. 890msl). Species diversity was higher in the tropical zone as compared to that of sub-tropical and lower temperate zones. Among the different seasons, species diversity was found to be highest during autumn.

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