TY - JOUR

T1 - Soil recovery after removal of the N2-fixing invasive Acacia longifolia: consequences for ecosystem restoration

AU - Marchante, Elizabete

AU - Kjøller, Annelise Helene

AU - Struwe, Sten

AU - Freitas, Helena

N1 - Keywords Ecosystem processes - Microbial activity and biomass - C and N-cycling - Potential nitrification - Soil ecology - ß-glucosaminidase activity

PY - 2009

Y1 - 2009

N2 - Invasion by Acacia longifolia alters soil characteristics and processes. The present study was conducted to determine if the changes in soil C and N pools and processes induced by A. longifolia persist after its removal, at the São Jacinto Dunes Nature Reserve (Portugal). Some areas had been invaded for a long time (>20 years) and others more recently (<10 years). For each type of invasion, (i.e., long-invaded and recently invaded), three treatments were used: (1) A. longifolia left intact; (2) A. longifolia was removed; and (3) both A. longifolia and litter layer were removed. Soil samples were collected once a year for four and half years and analysed for chemical and microbial properties. In general, microbial parameters responded faster than C and N pools. In long-invaded areas, two and half years after removal of plants and litter, basal respiration and microbial biomass had already decreased >30%, ß-glucosaminidase activity (N mineralization index) >60% and potential nitrification >95%. Removal of plants and litter resulted in a >35% decrease in C and N content after four and half years. In recently invaded areas, ß-glucosaminidase activity and potential nitrification showed a marked decrease (>54% and >95%, respectively) after removal of both A. longifolia and litter. Our results suggest that after removal of an N2-fixing invasive tree that changes ecosystem-level processes, it takes several years before soil nutrients and processes return to pre-invasion levels, but this legacy slowly diminish, suggesting that the susceptibility of native areas to (re)invasion is a function of the time elapsed since removal. Removal of the N-rich litter layer facilitates ecosystem recovery

AB - Invasion by Acacia longifolia alters soil characteristics and processes. The present study was conducted to determine if the changes in soil C and N pools and processes induced by A. longifolia persist after its removal, at the São Jacinto Dunes Nature Reserve (Portugal). Some areas had been invaded for a long time (>20 years) and others more recently (<10 years). For each type of invasion, (i.e., long-invaded and recently invaded), three treatments were used: (1) A. longifolia left intact; (2) A. longifolia was removed; and (3) both A. longifolia and litter layer were removed. Soil samples were collected once a year for four and half years and analysed for chemical and microbial properties. In general, microbial parameters responded faster than C and N pools. In long-invaded areas, two and half years after removal of plants and litter, basal respiration and microbial biomass had already decreased >30%, ß-glucosaminidase activity (N mineralization index) >60% and potential nitrification >95%. Removal of plants and litter resulted in a >35% decrease in C and N content after four and half years. In recently invaded areas, ß-glucosaminidase activity and potential nitrification showed a marked decrease (>54% and >95%, respectively) after removal of both A. longifolia and litter. Our results suggest that after removal of an N2-fixing invasive tree that changes ecosystem-level processes, it takes several years before soil nutrients and processes return to pre-invasion levels, but this legacy slowly diminish, suggesting that the susceptibility of native areas to (re)invasion is a function of the time elapsed since removal. Removal of the N-rich litter layer facilitates ecosystem recovery

U2 - 10.1007/s10530-008-9295-1

DO - 10.1007/s10530-008-9295-1

M3 - Journal article

VL - 11

SP - 813

EP - 823

JO - Biological Invasions

JF - Biological Invasions

SN - 1387-3547

IS - 4

ER -