Belowground effects of enhanced tropospheric ozone and drought in a beech/spruce forest (Fagus sylvatica L./Picea abies [L.] Karst).
The effects of experimentally elevated O(3) on soil respiration rates, standing fine-root biomass, fine-root production and delta(13)C signature of newly produced fine roots were investigated in an adult European beech/Norway spruce forest in Germany during two subsequent years with contrasting rainfall patterns. During humid 2002, soil respiration rate was enhanced under elevated O(3) under beech and spruce, and was related to O(3)-stimulated fine-root production only in beech. During dry 2003, the stimulating effect of O(3) on soil respiration rate vanished under spruce, which was correlated with decreased fine-root production in spruce under drought, irrespective of the O(3) regime. delta(13)C signature of newly formed fine-roots was consistent with the differing g(s) of beech and spruce, and indicated stomatal limitation by O(3) in beech and by drought in spruce. Our study showed that drought can override the stimulating O(3) effects on fine-root dynamics and soil respiration in mature beech and spruce forests.
Nikolova
Petia S
PS
Technische Universität München, Weihenstephan Center of Life and Food Sciences, Freising, Germany. nikolova@wzw.tum.de
Andersen
Christian P
CP
Blaschke
Helmut
H
Matyssek
Rainer
R
Häberle
Karl-Heinz
KH
D000393:Air Pollutants / Q000633:toxicity*; D057231:Climate Change; D055864:Droughts; D029964:Fagus / Q000187:drug effects* / Q000378:metabolism; D010126:Ozone / Q000633:toxicity*; D028222:Picea / Q000187:drug effects* / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects* / Q000378:metabolism; D012987:Soil / Q000032:analysis
D000393:Air Pollutants; D012987:Soil; D010126:Ozone