Phosphorus-acquisition and phosphorus-conservation mechanisms of plants native to south-western Australia or to Brazilian rupestrian fields

This thesis aimed to explore phosphorus acquisition and conservation mechanisms. Through field work I found functional equivalence in plant phosphorus nutrition of rupestrian fields (Brazil), kwongan (Western Australia) and fynbos (South Africa). I also recorded the first cluster roots in Brazil. In a glasshouse experiment, I detected stable internal phosphorus concentration in an Australian legume across phosphorus treatments, and observed that cluster root production was positively correlated with mycorrhizal colonisation. Another experiment demonstrated an inverse correlation between P-uptake down-regulation and P resorption from senescing leaves. My work interconnects ecophysiological aspects and has applicability in conservation and revegetation of P-impoverished environments.