Canadian Journal of Pure & Applied Sciences

Abstract: High resolution digital aerial photographs were used to rate the change and to evaluate the woody Prosopis juliflora dynamics in northern Unite Arab Emirates, Filayah (untreated) and Khut (treated). A time series of three different dates: 1986, 1996, and 2005 were chosen. On-screen digitizing of plant communities was conducted using interpretative elements such as shape, tone texture and shadow; production of final maps was achieved with acceptable accuracy. We built a geo-database containing layers representing different dates for both sites. We performed statistical analysis to rate changes of the following four spatial attributes: percent cover, patch density, patch size, and mean patch shape index. Finally, we conducted a GIS Overlay analysis to visualize plant dynamics and to explore possible spatial associations. Results confirm that Prosopis juliflora is a very active and dynamic invader which has the potential to threaten the local environment; as its percent cover as well as its patch density increased noticeably during the study period (1986-2005). We concluded that Prosopis juliflora seems to go through phases of expansion. First, an accelerated expansion earlier in the establishment period, then the distribution reaches a plateau. This plateau may be an optimum density of Prosopis juliflora in that region. The time period for such optimum is suggested to be 10 years from invasion.