Establishing a baseline on the distribution and pattern of occurrence of Salvadora persica L. with meteorological data and assessing its adaptation in the adjacent warmed-up zones.

The natural occurrence of Salvadora persica L., stretching from the coastal area of the Arabian sea to northward along the Indus floodplains, was surveyed to document the pattern of its occurrence with the available meteorological record showing increasing trends of frost northwards. Information was compiled from various sources to generate the past and present temperature data in order to establish relationship between the changing temperature factors and the extent of the area available due to climate change over the years for introducing species beyond its range of natural distribution. In addition, the species was experimentally introduced in the warmed-up zones to monitor its performance and to evaluate its adaptability. The reconnaissance survey showed that the natural populations of thorn forest communities with S. persica, as associate, are now surviving only as degraded remnants. Its common occurrence is documented in zones where the mean winter temperatures are above the threshold level of frost, whereas it is rarely found in zones where it drops below this level for a single month, which seems to be its range edge. S. persica does not occur in zones where low temperature could persist for 2 months. Recent temperature data suggests that the month of December has warmed up above the threshold level; therefore, it was expected that correspondingly the range edge of the frost-sensitive species has potentially shifted further northwards. The response of the species introduced at the experimental sites beyond its natural occurrence suggests high survival and growth, demonstrating its adaptability to the new sites beyond its limit of distribution.