Ameliorative effects of nurse shrubs on soil chemical characteristics are driven by plant size in the Monte desert

ORDANO, MARIANO; RATTALINO, DONNA; VARAS, MARIANA; CRABBÈ, FRANCO; ORDANO, MARIANO; VARELA, OMAR; CRABBÈ, FRANCO; VARAS, MARIANA; RATTALINO, DONNA; VARELA, OMAR

ARID LAND RESEARCH AND MANAGEMENT

TAYLOR & FRANCIS INC

Lugar: California; Año: 2017 vol. 31 p. 418 - 430

1532-4982

In deserts, shrubs determine landscape structure and influence plantproductivity by creating nutrient-enriched environments. Attributesvary among shrub species, thus their contribution to soil characteristicsis expected to vary as well, and nutrient input under shrub cover willdepend on species attributes. We propose that plant size determinesthe contribution to soil chemical characteristics. Therefore, thecontribution of larger species will be higher than smaller ones. Also,each species will contribute differentially for each chemical parameter.To corroborate these premises, we measured six soil chemicalcharacteristics in areas covered by shrubs and in bare soil, as well asamong five nurse species, in four sites of the Monte desert (La Rioja,Argentina). A multivariate analysis of variance (MANOVA) indicatedsignificant variation between cover conditions and locations. Supportingprevious studies, the presence of shrubs improved soil properties.Chemical concentration between soils under shrubs and bare soils,respectively, showed as mean and (SD) were: carbon(%): 0.82 (0,47), 0.52(0.22); nitrates (ppm): 33,33 (67,36), 2.63 (0.56); phosphorous(ppm):16.76 (25.02), 6.56 (1.92); electrical conductivity (dS m􀀀 1): 0.24 (0,43),0.03 (0,02); pH: 6.93 (0.56), 7.62 (0.53); and water content (%): 3,17 (8.94),2.47 (9.15). Chemical characteristics also varied according to the nursespecies. Larger nurse species affected the ensemble of chemicalcharacteristics, after controlling for cover condition and site. Largerplant species (Bulnesia retama, Prosopis torquata, and Zuccagniapunctata) were significantly associated with higher carbon and highernitrates concentration. These results suggest that soil properties areenhanced by the size of nurse plant species.