干旱区生态环境知识资源中心

Opuntia ficus-indica (L.) Mill. has been propagated for its fruits and young pads for human consumption, as well as for forage for domestic livestock for hundreds of years. Recently, it has been suggested that this plant could be beneficial in arid regions of the world where it has not been introduced. We used environmental tolerances for O. Ficus-indica gleaned from literature reviews, a rapid survey of this cactus growing in Jordan, and climatic data in a Geographic Information Systems (GIS) context to build a simple model of O. Ficus-indica suitability for Jordan. Rainfall and temperature were deemed the most important environmental variables to be employed in our model. We identified areas of the country within the range of annual rainfall between 250 and 505 mm and those with an absolute minimum temperature in any month above 1.5 degrees C. Climate data in our analysis came from the WorldClim GIS data set. We then eliminated areas with salt-affected soils. We extracted soil type, temperature and annual precipitation from the climatic GIS layers at twenty-one sites in Jordan where O. ficus-indica was found to be growing. Nineteen locations had aceptable values within the environmental tolerances for annual rainfall and temperature specified by the literature review. Two locations were drier than the recommended climatic range for the establishment of catus, and probably represent sites ameliorated by supplemental irrigation or water harvesting. A conservative figure of seven percent of Jordan's 89,342 km(2) was determined to have potential for cactus, based on aforementioned tolerances of temperature and annual rainfall. Inclusion of high-resolution soil information and digital elevation layer in the model, when they become available, would further refine the prediction of areas with potential for O. ficus-indica growth and cultivation.