Abstract:
Invasive alien species (IAS) have significant impact on natural and agricultural ecosystems in
the world which considered as irreversible and irreparable. Scientists have discussed about
ecological impacts of invasive alien plants in great detail and since recently the social and
economic impacts are also being considered as important. IAS also negatively effect on
agriculture and human health reducing the income from agriculture while increasing
expenditure on inputs. Its economic damage to tourism, fisheries, and forestry is immense.
However, social and economic damage of IAS could not exactly be estimated. In 2003, the
International Union for Conservation of Nature (IUCN), showed that the economic loss from
IAS is over 400 billion dollars annually and approximately $ 23 billion is lost due to the
effect of invasive plants on agriculture, industry, recreation and the environment.
This study was conducted in 2011 in Bellanvila-Attidiya area with the main objectives of
identifying the distribution of alien plant species and to find the major social and economic
impacts. Random sampling method was used to establish five field plots (10×10 m) for
collecting the floristic data. About 300 ground truths were collected and GeoEye1 and
Google Earth Images were used to identify the distribution of plants in the study area.
Satellite images were classified using unsupervised classification method. Questionnaire and
interviews were used to collect data to examine the social and economic impact of invasive
alien species. Stratified random sampling method was used to collecting these data (10,943
households and nine GN divisions were identified in this area) and descriptive statistical
analysis, ANOVA and chi-square test were used to analyse data. This study identified 13 IAS
and five invasive alien animals. Annona glabra was the most harmful one among all and
according to the result of questionnaire analysis, its socio-economic impact also high. This
study found that IAS was rapidly spreading at Bellanvila-Attidiya marsh and if necessary
actions are not taken, these invaders will rapidly encroach the entire area.
