RT info:eu-repo/semantics/article
T1 Time- and age-related effects of experimentally simulated nitrogen deposition on the functioning of montane heathland ecosystems
A1 Calvo Fernández, Javier
A1 Taboada Palomares, Ángela
A1 Fichtner, Andreas
A1 Härdtle, Werner
A1 Calvo Galván, María Leonor
A1 Marcos Porras, Elena María
A2 Ecologia
K1 Ecología. Medio ambiente
K1 Air pollution
K1 Calluna vulgaris heathland
K1 Plant-litter-soil nutrient relationship
K1 Extracellular enzymatic activity
K1 Soil microbial biomass
K1 Ericoid mycorrhizal colonization
AB Ecosystems adapted to low nitrogen (N) conditions such as Calluna-heathlands are especially sensitive to enhancedatmospheric N deposition that affects many aspects of ecosystem functioning like nutrient cycling,soil properties and plant-microbial-enzyme relationships. We investigated the effects of five levels of experimentally-simulated N deposition rates (i.e., N fertilization treatments: 0, 10, 20 and 50 kg N ha− 1 yr− 1 for3 years, and 56 kg N ha− 1 yr− 1 for 10 years) on: plant, litter, microbial biomass and soil nutrient contents,soil extracellular enzymatic activities, and plant root ericoid mycorrhizal colonization. The study was conductedin marginal montane Calluna-heathlands at different developmental stages resulting from management(young/building-phase and mature-phase). Our findings revealed that many soil properties did not show a statisticallysignificant response to the experimental addition of N, including: total N, organic carbon (C), C:Nratio, extractable N-NO3−, available phosphorus (P), urease and β-glucosidase enzyme activities, and microbialbiomass C and N. Our results also evidenced a considerable positive impact of chronic (10-year) high-Nloading on soil extractable N-NH4+, acid phosphatase enzyme activity, Calluna root mycorrhizal colonizationby ericoid fungi, Calluna shoot N and P contents, and litter N content and N:P ratio. The age of heathlandvegetation influenced the effects of N addition on ericoid mycorrhizal colonization, resulting in higher colonizedroots in young heathlands at the control, low and medium N-input rates; and in mature ones at the highand chronically high N rates. Also, young heathlands exhibited greater soil extractable N-NO3−, available P,microbial biomass N, Calluna shoot N and P contents, and litter N content, compared to mature ones. Ourresults highlighted that accounting for the N-input load and duration, as well as the developmental stage ofthe vegetation, is important for assessing the effects of added N, particularly at the heathlands' southern distributionlimit.
PB Elsevier
YR 2017
FD 2017-03-03
LK http://hdl.handle.net/10612/7422
UL http://hdl.handle.net/10612/7422
NO Science of the total environment, 2017, vol. 613-614
NO P. 149-159
DS BULERIA. Repositorio Institucional de la Universidad de León
RD 19-may-2024