Different patterns of gas exchange and photochemical efficiency in three desert shrub species under two natural temperatures and irradiances in Mu Us Sandy Area of China

Title:

Different patterns of gas exchange and photochemical efficiency in three desert shrub species under two natural temperatures and irradiances in Mu Us Sandy Area of China

Creator:

Jiang, G. M. and Zhu, G. J.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:61e869c5-3ac4-4fe9-b669-9729a800abdf
uuid:61e869c5-3ac4-4fe9-b669-9729a800abdf
issn:0300-3604
doi:10.1023/A:1013797023938

Subject:

Artemisia ordosia, chlorophyll fluorescence, diurnal courses, Hedysarum fruticosum var. mongolicum, irradiance, high temperature, photosynthetic rate, photosystem 2, stomatal conductance, and Salix pasmmophylla

Type:

model:article and TEXT

Format:

bez média and svazek

Description:

Field studies of gas exchange and chlorophyll fluorescence of three desert shrub species, Hedysarum fruticosum var. mongolicum, Artemisia ordosia, and Salix pasmmophylla, showed different patterns under different leaf temperature (T1) and incident photosynthetic photon flux density (PPFD). H. fruticosum var. mongolicum and A. ordosia exhibited higher PN and gs than S. pasmmophylla, especially under very high T1 (>46 °C) and high PPFD (>2 100 µmol m-2 s-1) in hot summer. The decreases of PN with the diurnal course were due mainly to stomata closure. However, PN of S. pasmmophylla was seriously depressed by very high temperature from midday to evening as shown by the negative PN in hot summer, whereas none of such depression was found in spring. Maximal spring photochemical efficiency of photosystem 2 (PS2), i.e, Fv/Fm, was the lowest at 16:00, indicating the injury of PS2 by heat at this stage. In hot summer again, all the three shrubs underwent pronounced midday depression of PN and gs, while in spring they showed a one-peak response. And the first peak appeared 2 h earlier in hot summer than in spring for all the three shrubs. It was the high temperature that led to the different patterns of gas exchange and the serious depression of PN in S. pasmmophylla. H. fruticosum var. mongolicum and A. ordosia were much more tolerant to heat and high irradiance than S. pasmmophylla, which fixed most of CO2 at the fast growing stage in spring. Nevertheless, in hot summer it had to survive the severe hot environment through strong respiration and storage of CO2 only in the early morning. and G. M. Jiang, G. J. Zhu.

Language:

Multiple languages

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Coverage:

257-262

Source:

Photosynthetica | 2001 Volume:39 | Number:2

Harvested from:

CDK

Metadata only:

false