The impact of livestock grazing on the spatial pattern of vegetation in north-eastern Patagonia, Argentina

FLAVIA A. FUNK; GUADALUPE PETER; LEDER CINTIA; LOYDI ALEJANDRO; KRÖPFL ALICIA; DISTEL ROBERTO A.

PLANT ECOLOGY & DIVERSITY

TAYLOR & FRANCIS LTD

Lugar: Londres; Año: 2018

1755-0874

Background:The occurrence of shrub patches, alternating with either bare soil or lowherbaceous cover, is a common feature in arid and semi-arid shrublandsthroughout the world. This patchy pattern of vegetation may result from waterlimitation, modulated by plant interactions; grazing (offtake and tramping) bylivestock may cause further patchiness vegetation structure.Aims: We hypothesisedthat vegetation patchiness in the semi-arid shrublands of north-eastern Patagonia would be increased by livestock grazing, butnot by positive interactions between adult plants of shrubs and grasses.Methods: Wecompared vegetation cover and pattern at three grazing intensities (exclosure, lightand heavy grazing) and measured the growth of a representative shrub and grassin the presence and absence of the other to quantify the role of plant-to-plantinteractions and its interaction with grazing for vegetation structure.Results: Inthe grazing exclosure and in moderately grazed areas, vegetation cover amongshrub patches was larger, whereas the top cover of shrubs was lower than in theheavily grazed areas. We did not find any evidence of positive interactionsbetween shrub and grass life forms.Conclusions:Our results were consistent with the hypothesis that livestock grazingincreased the formation of patchy vegetation cover in arid and semi-aridshrublands