Do invasive plants threaten the Sundarbans mangrove forest of Bangladesh?

Sundarbans mangrove forest has substantial ecological and economic importance at local, national and global scales. Over the past decades, invasive species have spread significantly in the mangrove ecosystem. We conducted a study to identify the different types of invasive species present, the rate and pattern of invasion, its intensity, association of invaders and their habitat preference in the Sundarbans mangrove ecosystem. Vegetation was sampled in 250 quadrats, each 10 m x 10 m, and 125 line transects each 100 m x 20 m; through a combination of random and systematic sampling. Altogether 23 plant species of two broad types'viz. aquatic weed and climbers were identified as invasive. Of the identified 23 invasive species, 19 are native or naturalized to Sundarbans mangrove. Invasives' abundance, diversity and rate of invasion (RI) were highest at the riverbanks and gradually decreased with increased proximity to the forests. Based on the severity of damage, species were classified as highly invasive, invasive and potentially invasive. Our study suggests that invasion in Sundarbans are still at a controllable stage. Continuous monitoring, policy change and management interventions must be triggered to target control of invasive plants of the Sundarbans. (c) 2007 Elsevier B.V. All rights reserved.