Forage provision is more affected by droughts in arid and semi-arid than in mesic rangelands

BONDARUK VIVIANA; OÑATIBIA GASTON; FERNÁNDEZ ROBERTO; AGÜERO WALTER; BLANCO, LISANDRO; BRUSCHETTI, C.M.; KRÖPFL ALICIA; LOYDI ALEJANDRO; PASCUAL JESUS; PABLO PERI; PETER GUADALUPE; QUIROGA EMILIANO; YAHDJIAN, LAURA

JOURNAL OF APPLIED ECOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2022

0021-8901

Droughtsare projected to increase in magnitude, frequency and duration in thenear future. In rangelands, the provision of valuable ecosystemservices (e. g. forage supply for livestock productivity) isintimately linked to rainfall patterns, which makes it particularlyvulnerable to extreme droughts. Nonetheless, rangelands can differ intheir sensitivity to droughts as shown by strong differences in theimpacts of inter-annual precipitation changes on vegetationproductivity in different sites. The aim of this study was to assessthe sensitivity to extreme droughts of nine rangelands located acrossa broad aridity gradient in Argentina, South America. Weexperimentally imposed comparable extreme droughts (ca.1/100 yr. occurrence)under field conditions by reducing incoming precipitation during 3consecutive years and assessed changes in forage productivity.We found that arid and semi-arid rangelands were more severelyimpaired in their forage provision by drought than mesic rangelands,i.e. that sensitivity to drought declined as aridity decreased. Theforage productivity decreased on average by 48.5% and 50%, in aridand semi-arid rangelands, respectively, whereas mesic sites did notexhibit significant changes between drought treatments and thecontrols. The negative impact in forage productivity of arid andsemi-arid rangelands was mainly driven by the productivity reductionof few key plant species. In seven of the nine rangelands, we foundthe detrimental effects of drought on forage productivity during thefirst drought-experimental year which indicates a serious threat ofthese extreme events even in the short-term. Our results highlightthe urgent need to implement management efforts to mitigate droughtdetrimental consequences on rangelands, particularly on arid andsemi-arid regions, since they provide essential ecosystem servicesstrongly associated with human well-being.