Diversity, Distribution And Control Of Aquatic Macrophytes Of Southern Ghana With Particular Reference To The Alien Invasives

ABSTRACT

The diversity and distribution of aquatic macrophytes particularly the invasives were studied in southern Ghana. The study area covered six regions in Ghana and these were: Greater Accra, Central, Ashanti, Eastern, Volta and Western. Forty-four sampling sites were visited and voucher specimens were collected and deposited in the Ghana Herbarium. Sixty-two aquatic macrophytes were encountered during the study which belonged to 48 genera and 30 families. Also, the invasive and non-invasive aquatic macrophytes that were encountered were also grouped according to the families they belonged. The Cyperaceae family emerged as the most dominant with 9 species. The criteria of IUCN (2004) were used in the identification of whether a particular species was an invasive or not. Based on this, the encountered aquatic macrophytes were separated into invasives and non-invasives. Eleven of the species were identified as invasives whereas the remaining fifty-two aquatic species were non-invasives. The life forms of the aquatic macrophytes were also determined. Forty one species (67%) were emergent, eleven species (17%) were free-floating, eight species (13%) were submerged and two species (3%) were floating-leaved. Distribution maps were drawn for the eleven invasive aquatic plants that were encountered. Pistia stratiotes was the most distributed invasive aquatic plant within the Southern part of Ghana with a total of seven distribution spots. A database was also created for all the sixty-two invasive and non- invasive species encountered. These comprised the scientific name and photograph of the species, synonym, common name, family, description, reproduction, habitat, distribution and uses. For each of the invasive aquatic macrophytes, the method of control was reviewed so as to make use of the best methods available that would help in their control/management.