Chemo-ecotone’s soil characteristics and their effect on the ionic content and plants distribution

Abstract

The chemo-ecotone (Kamel 2003) is influenced usually by the chemical characteristic of the soil that causes the environmental gradient. The aim of the current work is to study the plants responses to overcome the high soil sodicity SAR. The impact of soil sodicity on the species distribution across the ecotone. Eleven species were selected for investigation. Soil analysis showed that SAR decreased far away from the sea gradually, causing environmental gradient. To overcome the soil salinity and sodium toxicity, the halophytes and salt resistant plants accumulated Na+ ions more than true xerophytes. All species were dependent on potassium and calcium as compatible solutes to avoid sodium toxicity. The results showed that vegetation diversity at the chemo-ecotone was controlled by soil sodicity and the ability of plants to overcome salinity. The chemo-ecotone width depended upon the ability of true desert species, Lotus hebranicus, to disperse toward the sea, as well as the true halophytes, Limonium pruinosum, toward the desert. It is concluded that the species diversity in the chemo-ecotone depends mainly on the soil sodicity as a limiting factor.

Growth, productivity and phytochemicals of Coriander in responses to foliar application of Acacia saligna fruit extract as a biostimulant under field conditions

“…The methanolic extracts of A. saligna had a greater impact on the seedling length of the plant diversity along Egypt's Nile Delta Coast than the aqueous extracts, but only at low doses 54 . Two agricultural crops, wheat and canola, showed persistent declines in their vegetative growth parameters (shoot and root length, fresh and dry weight), as the allelopathic extract concentration from leaves and stems of A. saligna increased to 10% 56 . A. saligna leaf and root aqueous extract concentrations (0%, 5%, 10%, 15%, and 20%) significantly increased the inhibition of seed germination and the lengthening of shoot and root, which gradually reduced the seedling performance of three native Mediterranean shrubs ( Astragalus armatus Willd., Retama raetam (Forssk.)…”

“…It is also described as a woody tree that grows quickly, is invasive, and has a sizable quantity of protein (18.25–35.5%) 53 . A. saligna extracts from the stem and leaves contain allelopathic compounds that are thought to be phytotoxic and inhibits plant development or germination 54 – 56 .…”