Relationships between empirical and nominal indices of landscape function in the arid shrubland of Western Australia

The area occupied by vegetated patches in comparison with area of the inter-patch, is becoming an accepted and useful standard against which to assess ecosystem function in arid and semi-arid environments. Proportional areas of vegetated patches were found to be positively correlated with oxidizable C and total N in surface soil in low-woodland, but not in low-shrubland communities. Suggested indices of soil-surface condition and derived ratings of landscape function were positively related to soil fertility but less clearly with proportional areas of vegetated patches. These relationships were community-type specific. It is unclear whether the suggested approach provides more information on landscape function than simple measures of patch heterogeneity. Patch-structure of low-woodland, compared to low-shrubland communities, may be more resistant to disturbance, however once disturbed, low-woodland is less resilient in that nutrient losses are likely to be greater.