TY - JOUR
T1 - Evergreen leaf respiration acclimates to long-term nocturnal warming under field conditions
AU - Bruhn, Dan
AU - Egerton, John J.G.
AU - Loveys, Beth R.
AU - Ball, Marilyn C.
PY - 2007/6/1
Y1 - 2007/6/1
N2 - Acclimation of plant respiration rates (R) to climate warming is highly variable and many results appear contradictory. We tested the recently suggested hypotheses that pre-existing, long-lived leaves should exhibit a relatively limited ability for R to acclimate to climate warming, and that acclimation would occur via changes in the short-term temperature sensitivity of respiration. Seedlings of a subalpine, evergreen tree species (Eucalyptus pauciflora) were grown under naturally fluctuating conditions within its natural distribution. We used a free air temperature increase (FATI) system of infra-red ceramic lamps to raise night-time leaf temperatures by 0.3±0.1, 1.3±0.1, and 2.2±0.1 °C above ambient for 1 year. Light-saturated assimilation rates and plant growth did not change with nocturnal FATI treatments. Leaf R measured at prevailing temperatures did not differ between FATI treatments. Within each FATI treatment, nocturnal leaf R was highly sensitive to artificial temperature changes within minutes, and also correlated strongly with natural nocturnal and seasonal temperature variation. The corresponding values of Q10 of R varied according to time scale of measurements, but did not vary between FATI treatments. Instead, acclimation of R to nocturnal FATI occurred through changes in the base rate of respiration.
AB - Acclimation of plant respiration rates (R) to climate warming is highly variable and many results appear contradictory. We tested the recently suggested hypotheses that pre-existing, long-lived leaves should exhibit a relatively limited ability for R to acclimate to climate warming, and that acclimation would occur via changes in the short-term temperature sensitivity of respiration. Seedlings of a subalpine, evergreen tree species (Eucalyptus pauciflora) were grown under naturally fluctuating conditions within its natural distribution. We used a free air temperature increase (FATI) system of infra-red ceramic lamps to raise night-time leaf temperatures by 0.3±0.1, 1.3±0.1, and 2.2±0.1 °C above ambient for 1 year. Light-saturated assimilation rates and plant growth did not change with nocturnal FATI treatments. Leaf R measured at prevailing temperatures did not differ between FATI treatments. Within each FATI treatment, nocturnal leaf R was highly sensitive to artificial temperature changes within minutes, and also correlated strongly with natural nocturnal and seasonal temperature variation. The corresponding values of Q10 of R varied according to time scale of measurements, but did not vary between FATI treatments. Instead, acclimation of R to nocturnal FATI occurred through changes in the base rate of respiration.
KW - Acclimation
KW - Climate warming
KW - Field
KW - Free air temperature increase (FATI)
KW - Leaf
KW - Q
KW - Respiration
KW - Temperature sensitivity
UR - http://www.scopus.com/inward/record.url?scp=34250375112&partnerID=8YFLogxK
U2 - 10.1111/j.1365-2486.2007.01351.x
DO - 10.1111/j.1365-2486.2007.01351.x
M3 - Journal article
AN - SCOPUS:34250375112
SN - 1354-1013
VL - 13
SP - 1216
EP - 1223
JO - Global Change Biology
JF - Global Change Biology
IS - 6
ER -