Spatio-temporal effects on association of plant species in Soone Valley of Pakistan.

摘要

Six ecologically diverse study sites viz., Khabeki, Khoora, Dape Sharif, Anga, Knotti Garden and Jallar were selected mainly on the basis of differences in their environmental attributes especially variations in elevation, slope, aspect, altitude, topography, soil composition, habitat, vegetation type and plant community. The available plant species at selected sites were enlisted. The ecological data was recorded during all the four seasons (autumn, winter, spring and summer) using quadrate sampling method. Soil physical and chemical properties of each site had their own impacts on the species association but seasonal effects, which were particularly due to different temperature and rain falls during different seasons of the year, were more pronounced. Most of the herbaceous species were frequent during summer and autumn due to suitable temperature and availability of moisture and nutrients. However during winter sparse vegetation did not show grouping of plants due to severe cold temperature. Availability of different nutrients at different sites and similar ability of some species to absorb these nutrients also had significant effect on association of species. Species sharing similar habitat were mostly associated as moisture loving species were grouped around water springs of Knotti Garden and Dape Sharif. Salt tolerant species were associated at Jailer site. Species which can tolerate both high salinity and pH were associated at Anga and Khoora sites.