Arbuscular mycorrhizal association and dependency determined the pioneer plant community, diversity structure and plant cover in two river bank under same climate

Early colonization of plants in an area is influenced mostly by climatic, edaphic and phytogeographic factors. As arbuscular mycorrhizae (AM) was associated with early invasion of land plants on earth, AM may have some role in defining the first seral community in any land. Two riverbanks were selected to study their pioneer plant community structure with species composition and diversity, soil characters and arbuscular mycorrhizal association; and correlations among these factors. Species composition, diversity and richness indices, active AM association of early colonizing plant species, soil texture, moisture, pH and E.C in two river banks differed. Similarity index for plant species between the two communities was poor. Diversity and richness indices were high in K site while evenness was high in R site. AM colonization and spore density correlated highly with plant cover and frequency in both riverbanks. Soil moisture showed a strong negative impact on mycorrhization, soil organic carbon showed little. Soil pH showed varied correlation in different sites. Early colonizing plants in R site with silt-loam soil with high moisture level are found poorly mycotrophic or nonmycotrophic; though plant cover correlated highly with mycotrophy in both sites. Plants in sandy soil of K site are highly mycotrophic and with high arbuscular and vesicular colonizations. The distribution of frequency in R site is highly deviated from Raunkiuer’s frequency class; in K site it is rather stable. The soil condition is only key factor to determine plant composition and plant-mycorrhizal relations influencing colonization of early seral community.