SEMINAR: Next CLR Seminar: Prof. Hans Lambers, Plant Biology

Centre for Land Rehabilitation Seminar, School of Earth and Environment, FNAS. - All welcome!

Prof. Hans Lambers: "Phosphorus nutrition and growth strategies of plants in a global biodiversity hotspot".

Abstract:Some of the most ancient parts of the Earth’ crust can be found in Western Australia, where the climate there has been oceanically buffered, and the landscape has not been glaciated for over 90 million years. The southwest of Western Australia is also one of the world’s hotspots of biodiversity, with plant diversity increasing with decreasing soil [P]. This environment offers a unique opportunity to study plant adaptations to nutrient-poor conditions.

A relatively large proportion of the species from the very phosphorus-poor soils in Western Australia cannot produce a symbiotic association with a mycorrhizal fungus, including most species belonging to the Proteaceae and Cyperaceae. Instead, many species in these families produce root clusters, which release large amounts of carboxylates, whose role is that of mobilisation of phosphorus (P) and micronutrients.

Leaf P concentrations in south-western Australia are amongst the very lowest in the world. Leaf N concentrations are also low, but relatively less so than leaf [P], and hence foliar N:P ratios are relatively high, compared with global datasets. Very high values for leaf mass per unit area, compared with data for plants elsewhere in the world, only partly account for low leaf [P]. For reasons that remain to be explored further, leaves of many south-western Australian plants are capable of functioning at very low leaf [P], including exhibiting relatively high rates of photosynthesis.