INVESTIGADORES
GALETTO Leonardo
artículos
Título:
Forest fragment size and nutrient availability: complex responses of mycorrhizal fungi in native–exotic hosts.
Autor/es:
GRILLI, G.; URCELAY, C.; GALETTO, L.
Revista:
PLANT ECOLOGY
Editorial:
SPRINGER
Referencias:
Lugar: Berlin; Año: 2012 vol. 213 p. 155 - 165
ISSN:
1385-0237
Resumen:
In the past few decades, it has beenwidely accepted that forest loss due to human actionsalter the interactions between organisms. We studiedthe relationship between forest fragment size andarbuscular mycorrhizal fungi (AMF) and dark septateendophytes (DSE) colonization, and the AMF sporecommunities in the rhizosphere of two congenericEuphorbia species (native and exotic/invasive). Wehypothesized that these fungal variables will differwith fragment size and species status, and predictedthat (a) AMF and DSE colonization together withAMF spore abundance and diversity would bepositively related to forest fragment size; (b) theserelationships will differ between the exotic and thenative species; and (c) there will be a negativerelationship between forest fragment size and theavailability of soil nutrients (NH4?, NO3-, andphosphorus). This study was performed in the eightrandomly selected forest fragments (0.86–1000 ha),immersed in an agricultural matrix from the Chaqueanregion in central Argentina. AMF root colonizationin the native and exotic species was similar, andwas positively related with forest fragment size.Likewise, AMF spore diversity and spore abundancewere higher in the larger fragments. While DSE rootcolonization in the native host was positively relatedwith forest fragment size, DSE colonization in theexotic host showed no relationship. Soil nutrientscontents were negatively related with forest fragmentsize. In addition, NH4? and NO3- were negativelycorrelated with AMF spores abundance and rootcolonization and with DSE colonization in the nativespecies. The results observed in this study show howhabitat fragmentation might affect the interactionbetween key soil components, such as rhizosphericplant-fungal symbiosis and nutrient availability.These environmental changes may have importantconsequences on plant community composition andnutrient dynamics in this fragmented landscape.