Responses of Dobera glabra and Eight Co-Occurring Species to Drought and Salinity Stress at a Savanna-Scrub Ecotone: Implications in the Face of Climate Change uri icon

abstract

  • To quantify the resistance of different co -occurring species to drought and osmotic stress (salinity stress), plant water (Ψ) and osmotic (Ψ Ï? ) potentials were measured during the dry season. We ap - plied a pressure chamber and cryoscopy to measure Ψ and Ψ Ï? , respectively. The species revealed a wide range of responses to water stress ( â?? 0.8 3 to â?? 5.8 MPa) and osmotic stress ( â?? 1.3 to â?? 3.2 MPa) and not all plants fit closely into one or the other category. Evergreen species tended to have lower Ψ than deciduous species. Notably, Dobera glabra , well known as drought indicator tree in the re- gio n, showed the lowest Ψ (up to â??5.8 MPa) and Ψ Ï? ( â?? 3.2 MPa). This indicates its outstanding drought and osmotic stress tolerance and explains its ability to thrive in drought prone areas and years. The recent expansion of A. oerfota and A. mellifera in the study area could be related to their tolerance of osmotic stress, which may imply a trend of soil salinization. The division of plant re- sponses into categories or strategies can be valuable aid to understanding long -term plant sur - vival and dist ribution, monitor site condition and predict the direction of future changes

publication date

  • 2014