Unexpectedly, intense livestock grazing in arid rangelands strengthens the seed-ling vigor of consumed plants.

M. TADEY; SOUTO, C. P.

AGRONOMY FOR SUSTAINABLE DEVELOPMENT

EDP SCIENCES S A

Lugar: Paris; Año: 2016

1774-0746

Grazing intensification with non-native livestock is11 known to degrade vegetation cover, particularly in arid envi-12 ronments where low resource availability strongly limits plant13 recovery after damage. However, it remains unclear whether14 the effect of grazing on consumed plants is transmitted to plant15 offspring. We hypothesized that grazing would reduce fruit16 weight, germination percentage, and seedling vigor of con-17 sumed vegetation. Therefore, we collected mature fruits from18 six dominant shrub species in seven independent paddocks19 with increasing livestock densities. Fruits were air-dried and20 weighed before seed sowing. After seedling emergence, we21 measured the percentage of germination and seedling vigor,22 i.e., height and number of leaves. Hierarchical models were23 used to account for the effects of plant species and year of24 collection. Results show that, in general, increasing livestock25 density reduced fruit weight and percentage of germination of26 consumed plants. However, surprisingly, increasing livestock27 density enhanced seedling vigor. Overall, increasing livestock28 density has both negative and positive effects on consumed29 plants offspring.