Aims
We estimate organic carbon (C): total nitrogen (N): total phosphorus (P) ratios in soils under Australia’s major native vegetation groups.
Methods
We use digital datasets for climate soils and vegetation created for the National Land and Water Resources Audit in 2001. Analysis-of-variance is used to investigate differences in nutrient ratios between ecosystems. Linear discriminant analysis and logistic regression are used to investigate the relative importance of climatic variables and soil nutrients in vegetation patterns.
Results
We find that the N:P and C:P ratios have a greater range of values than the C:N ratio although major vegetation groups tend to show similar trends across all three ratios. Some apparently homeostatic groupings emerge: those with very low low medium or high N:P and C:P. Tussock grasslands have very low soil N N:P and C:P probably due to frequent burning. Eucalypt woodlands have low soil N:P and C:P ratios although their total P level varies. Rainforests and Melaleuca forests have medium soil N:P and C:P ratios although their total P level is different. Heathlands tall open eucalypt forests and shrublands occur on soils with low levels of total P and high N:P and C:P ratios that reflect foliar nutrient ratios and recalcitrant litter.
Conclusions
Certain plant communities have typical soil nutrient stoichiometries but there is no single Redfield-like ratio. Vegetation patterns largely reflect soil moisture but for several plant communities eucalypt communities in particular soil N and P (or N:P) also play a significant role. Soil N:P and the presence of Proteaceae appear indicative of nutrient constraints in ecosystems.
【高寒地区植物和土壤对氮素添加的响应】Yongwen Liu Xu-Ri Xingliang Xu Da Wei Yinghong Wang Yuesi Wang. Plant and soil responses of an alpine steppe on the Tibetan Plateau to multi-level nitrogen addition. Plant and Soil
