Fig 4. Variation explained by abiotic vs. biotic variables.

Relative variation in species composition explained by abiotic (black) and biotic (grey) environmental variables in site-wise redundancy analyses (RDA) performed across eleven grassland sites in alpine, sub alpine and boreal sites along a precipitation gradient from low (1) to high (4) in southern Norway. LOI refers to Loss-On-Ignition, a measure of soil organic matter.