Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - European semiarid Mediterranean ecosystems are sensitive to nitrogen deposition
T2 - impacts on plant communities and root phosphatase activity
AU - Ochoa-Hueso, Raul
AU - Stevens, Carly J.
PY - 2015/2/1
Y1 - 2015/2/1
N2 - Nitrogen (N) deposition is predicted to impact on the structure and functioning of Mediterranean ecosystems. In this study, we measured plant species composition, production and root phosphatase activity in a field experiment in which N (0, 10, 20 and 50 kg N ha(-1) year(-1)) was added since October 2007 to a semiarid shrubland in central Spain. The characteristically dominant annual forb element responded negatively to N after similar to 2.5 and similar to 3.5 years. In contrast, the nitrophilous element (mainly crucifers) increased with N after similar to 2.5 and similar to 5.5 years, a response controlled by between-year variations in rainfall and the heterogeneous distribution of P availability. We also described a hierarchy of factors driving the structure and composition of the plant community: soil fertility was the most important driver, whereas calcareousness/acidity of soils and shrub cover played a secondary role; finally, N deposition contributed to explain a smaller fraction of the total variance, and its effects were predominantly negative, which was attributed to ammonium toxicity. Root phosphatase activity of three species was not responsive to N after similar to 2.5 years but there was a negative relationship with soil P in two of them. We conclude that increased N deposition in semiarid Mediterranean ecosystems of Europe can contribute to cause a shift in plant communities associated with an increase in the nitrophilous element and with a decline in abundance of various forb species adapted to the local conditions.
AB - Nitrogen (N) deposition is predicted to impact on the structure and functioning of Mediterranean ecosystems. In this study, we measured plant species composition, production and root phosphatase activity in a field experiment in which N (0, 10, 20 and 50 kg N ha(-1) year(-1)) was added since October 2007 to a semiarid shrubland in central Spain. The characteristically dominant annual forb element responded negatively to N after similar to 2.5 and similar to 3.5 years. In contrast, the nitrophilous element (mainly crucifers) increased with N after similar to 2.5 and similar to 5.5 years, a response controlled by between-year variations in rainfall and the heterogeneous distribution of P availability. We also described a hierarchy of factors driving the structure and composition of the plant community: soil fertility was the most important driver, whereas calcareousness/acidity of soils and shrub cover played a secondary role; finally, N deposition contributed to explain a smaller fraction of the total variance, and its effects were predominantly negative, which was attributed to ammonium toxicity. Root phosphatase activity of three species was not responsive to N after similar to 2.5 years but there was a negative relationship with soil P in two of them. We conclude that increased N deposition in semiarid Mediterranean ecosystems of Europe can contribute to cause a shift in plant communities associated with an increase in the nitrophilous element and with a decline in abundance of various forb species adapted to the local conditions.
KW - Ammonium
KW - Calcareousness
KW - Inorganic N
KW - Local forbs
KW - Mediterranean ecosystems
KW - N deposition
KW - Nitrophilous plants
KW - Phosphorus availability
KW - Shrub cover
KW - Soil fertility
KW - SOIL
KW - PHOSPHORUS
KW - GRASSLANDS
KW - ENRICHMENT
KW - FERTILITY
KW - ADDITIONS
KW - GRADIENT
U2 - 10.1007/s11270-014-2278-1
DO - 10.1007/s11270-014-2278-1
M3 - Journal article
VL - 226
JO - Water, Air, and Soil Pollution
JF - Water, Air, and Soil Pollution
SN - 0049-6979
IS - 2
M1 - 5
ER -