BOTA2000 Lecture Notes - Lecture 11: Soil Ph, Rhizosphere, Fire Regime
Document Summary
Symbiotic association of millions of photosynthetic microorganisms in a mesh of fungal hyp hae. Mycorrhizae: symbiotic associations between plant roots and fungi, mycorrhizal associations obtain phosphorus and other nutrients for plant and organic carbon for fungus. Characteristic of the climate the major driver of biotic patterns globally (climate stability. Landscape age influential in evolutionary traits & niche patterning (landscape age: fireas a glo(cid:271)ally rele(cid:448)a(cid:374)t disturbance driver of evolution (fire regime first plants to invade land) Human disturbance often detrimental criticality of leaving topsoil intact. Avoid importation of nutrients, groundwater extraction, logging. Particular land management activities exacerbate impacts of climate change in osls. Interacting threatening processes exacerbate impacts of climate change in osls. A novel root modification in response to p-poor soils. Growth is induced by p-deficiency (are not formed in high p soils) Exude organic compounds (citrate, malate) into the immediate soil (rhizosphere) that decreases the soil ph. These mobilise p that is otherwise unavailable to the plant.
