Distribution spread and impact of broussonetia papyrifera a fast emerging invasive tree species

Abstract

In the study, attempts are made to study the impact of its invasion on the understory vegetation to predicting its implications on community composition, so that the appropriate precautionary/management measures can be undertaken. The phenological aspects, functional traits and litter decomposition of B. papyrifera are also explored and compared with non-invasive con-familial species, Morus alba to understand its life cycle and invasion success. The spread of B. papyrifera was observed in eleven of the fourteen study sites in Chandigarh, comprising of three habitats, i.e., forest margins, roadside and wastelands further classified into four invasion classes, i.e., control (B. papyrifera rare or unavailable), sparsely invaded (IVI lt 100), moderately invaded (IVI 101and#8210;200) and highly invaded (IVI 201and#8210;300). The species richness was observed to decline with the invasion of B. papyrifera. The dominance of B. papyrifera increased with its increasing invasion; however, the diversity of species significantly decreased with the increase in the invasion of B. papyrifera. Broussonetia papyrifera favored the persistence of exotic species. Phenological studies of B. papyrifera were carried out in Panjab University, Chandigarh, India; as per an internationally recognized and scientifically acceptable phenological scale known as BBCH (Biologische Bundesanstalt, Bundessortenamt and CHemishe Industrie) scale. It was found that B. papyrifera has two developmental cycles in a single calendar year. The reproductive phase of B. papyrifera, constituted the major part of its life cycle, (7 months), which not only enhanced its reproductive output but also provided a longer window for seed dispersal. We hypothesized that an average daily temperature of about 28°C is required for fruit development in B. papyrifera, which was observed to be similar in both the cycles. The leaf functional traits significantly varied between B. papyrifera and M. alba.