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Limits to the height growth of Caragana korshinskii resprouts.
- Source :
-
Tree Physiology . Mar2013, Vol. 33 Issue 3, p275-284. 10p. - Publication Year :
- 2013
-
Abstract
- Predawn leaf water potential (LWP), the LWP between 09:00 and 10:30 h (termed minimum LWP), stem xylem hydraulic conductivity, foliar nitrogen, leaf gas exchange and leaf traits were measured on the same days in adults and 1-year-old to 7-year-old resprouts that had regrown after removing all the aboveground shoots. Height growth and accumulation of aboveground biomass quickly decreased with resprout age and there was no difference between 7-year-old resprouts and the uncut adults. Predawn LWP showed no significant difference between resprouts and adults, but the minimum LWP decreased gradually from −2.0 MPa in 1-year-old resprouts to −3.0 MPa in 7-year-old resprouts. The decrease in minimum LWP was associated with increased hydraulic resistance, as indicated by the gradual decrease in leaf area-specific hydraulic conductivity (KL) and sapwood area-specific hydraulic conductivity (KS) and the associated increase in stem native percentage loss of hydraulic conductivity in older than 2-year-old resprouts. The leaf nitrogen content per unit area (Narea) also decreased steadily from 3.6 g m−2 in 1-year-old resprouts to 1.7 g m−2 in 7-year-old resprouts. With the decline in LWP and Narea, the rate of leaf photosynthesis per unit area (Aarea) decreased from 20 μ mol m−2 s−1 in 1-year-old resprouts to 11 μ mol m−2 s−1 in 7-year-old resprouts. In adults, although KS decreased further compared with 7-year-old resprouts, the minimum LWP, KL, Narea and the rate of photosynthesis increased by 0.3 MPa, 29, 34 and 23%, respectively. The results show that a progressive loss of stem hydraulic conductivity and a steady decrease in foliar nitrogen with age were associated with a decrease in the photosynthetic rate of Caragana korshinskii Kom. resprouts, possibly changing the allocation of photosynthetic assimilates and slowing resprout height growth. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 0829318X
- Volume :
- 33
- Issue :
- 3
- Database :
- Academic Search Index
- Journal :
- Tree Physiology
- Publication Type :
- Academic Journal
- Accession number :
- 86427947
- Full Text :
- https://doi.org/10.1093/treephys/tpt006