Seasonal changes in photosynthesis and stomatal conductance of five plant species from a semiarid ecosystem

Title:

Seasonal changes in photosynthesis and stomatal conductance of five plant species from a semiarid ecosystem

Creator:

Tezara, W., Fernández, M. D., Donoso, C., and Herrera, A.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:fc758e0f-9411-4860-b328-581c6c94fe12
uuid:fc758e0f-9411-4860-b328-581c6c94fe12
issn:0300-3604
doi:10.1023/A:1006916419260

Subject:

Alternanthera crucis, C3 and C4 plants, Capparis odoratissima, drought, intercellular CO2 concentration, Ipomoeacarnea, Jatropha gossypifolia, photosynthetic rate, and Prosopis juliflora

Type:

model:article and TEXT

Format:

bez média and svazek

Description:

In order to determine whether stomatal closure alone regulates photosynthesis during drought under natural conditions, seasonal changes in leaf gas exchange were studied in plants of five species differing in life form and carbon fixation pathway growing in a thorn scrub in Venezuela. The species were: Ipomoea carnea, Jatropha gossypifolia, (C3 deciduous shrubs), Alternanthera crucis (C4 deciduous herb), and Prosopis juliflora and Capparis odoratissima (evergreen phreatophytic trees). Xylem water potential (Ψ) of all species followed very roughly the precipitation pattern, being more closely governed by soil water content in I. carnea and A. crucis. Maximum rate of photosynthesis, Pmax, decreased with Ψ in I. carnea, J. gossypifolia, and A. crucis. In I. carnea and J. gossypifolia stomatal closure was responsible for a 90 % decline in net photosynthetic rate (PN) as Ψ decreased from -0.3 to -2.0 MPa, since stomatal conductance (gs) was sensitive to water stress, and stomatal limitation on PN increased with drought. In A. crucis, PN decreased by 90 % at a much lower Ψ (-9.3 MPa), and gs was relatively less sensitive to Ψ. In P. juliflora and C. odoratissima, Pmax, gs, and intercellular CO2 concentration (Ci) were independent of soil water content. In the C3 shrubs stomatal closure was apparently the main constraint on photosynthesis during drought, Ci declining with Ψ in I. carnea. In the C4 herb, Ci was constant along the range of Ψ values, which suggested a coordinated decrease in both gs and mesophyll capacity. In P. juliflora Ci showed a slow decrease with Ψ which may have been due to seasonal leaf developmental changes, rather than to soil water availability. and W. Tezara ... [et al.].

Language:

Multiple languages

Rights:

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

Coverage:

399-410

Source:

Photosynthetica | 1998 Volume:35 | Number:3

Harvested from:

CDK

Metadata only:

false