The Species Richness of Vascular Plants and Amphibia in Major Plant Communities in Temperate to Tropical Australia: Relationship with Annual Biomass Production

Figure 6

(a) Number (𝑁) of species of Amphibians in nutrient-rich, medium-nutrient, nutrient-poor, and extremely nutrient-poor habitats in northern and southern Australia (Table 1), plotted against the Evaporative Coefficient (𝑘) of the sampling locality [26]. Perhumid climatic zone–𝑘>0.75×10⁻²; humid climatic zone—𝑘=0.75−0.55×10⁻²; subhumid climatic zone—𝑘=0.55−0.45×10⁻²; semiarid climatic zone—𝑘=0.45−0.35×10⁻²; arid climatic zone—𝑘<0.35×10⁻². Nutrient-rich soils (Nth Aust.): 𝑁 = 0.737 k−11.01 (𝑛=4, 𝑟²=0.93). Medium-nutrient soils (Nth Aust.): 𝑁 = 0.629 k−11.61 (𝑛=6, 𝑟²=0.94). Nutrient-rich soils (Vic.): 𝑁 = 9 when 𝑘=0.45×10⁻² (only one site). Medium-nutrient soils (SE Aust.): 𝑁 = 0.300 k −5.59 (𝑛=8, 𝑟²=0.98). Nutrient-poor soils (SW Aust.): 𝑁 = 0.267 k −7.99 (𝑛=9, 𝑟²=0.98). Extremely nutrient-poor soils (S.A.): 𝑁 = 0.282 k −12.22 (𝑛=4, 𝑟²=0.93). (b) Number (𝑁) of species of Amphibians in nutrient-rich, medium-nutrient, nutrient-poor, and extremely nutrient-poor habitats in northern and southern Australia, plotted against the annual shoot growth (ASG, t ha⁻¹) of the major plant formation at the sampling site: 𝑁 = 3.81 ASG −2.56 (𝑛=32, 𝑟²=0.98).

(a)

(b)