Data from: Do grazing intensity and herbivore type affect soil health? Insights from a semi-arid productivity gradient

Grazing is one of the most widespread forms of intensive management on
Earth and is linked to reductions in soil health. However, little is known
about the relative influence of herbivore type, herbivore intensity and
site productivity on soil health. This lack of knowledge reduces our
capacity to manage landscapes where grazing is a major land use. We used
structural equation modelling to assess the effects of recent (cattle,
sheep, goats, kangaroos and rabbit dung) and historic (cattle, sheep/goat
livestock tracks) herbivore activity on soil health at 451 sites across
0·5 M km2 of eastern Australia. We assessed the direct and indirect
effects of increasing herbivore intensity, using dung and livestock
tracks, on 15 morphological, physical and chemical attributes that are
indicative of soil health, and we used these attributes to derive three
indices representing the capacity of the soil to maintain its structural
integrity (stability), cycle nutrients (nutrients) and maintain water flow
(infiltration). Grazing had negative effects on the three soil health
indices, but these effects varied with productivity. Grazing intensity was
associated with strong reductions in the stability and nutrient indices
under low productivity, but these effects diminished with increasing
productivity. Herbivore effects on individual attributes varied in
relation to productivity level and were strongly herbivore specific, with
most due to cattle grazing, and to a lesser extent, sheep, goats and
rabbits. Few effects due to kangaroos or historic grazing by livestock
were observed. Synthesis and applications. Our study shows that livestock
and rabbits degrade soil health through grazing, and its effects are
strongest under low or moderate productivity; however, kangaroo effects
are benign. Our findings support calls for resource management agencies to
consider site productivity, as well as herbivore type and intensity, when
developing strategies to manage grazing by livestock, and feral and native
herbivores.