Variations in daytime net carbon and water exchange in a montane shrubland ecosystem in southeast Spain

Title:

Variations in daytime net carbon and water exchange in a montane shrubland ecosystem in southeast Spain

Creator:

Serrano-Ortiz, P., Kowalski, A. S. , Domingo, F., Rey, A., Pegoraro, E., Villagarcía, L., and Alados-Arboledas, L.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:8befd4ae-3b15-46b9-9d71-c886c4746273
uuid:8befd4ae-3b15-46b9-9d71-c886c4746273
issn:0300-3604
doi:10.1007/s11099-007-0005-5

Subject:

carbon dioxide flux, eddy covariance, phenology, photon flux density, shrubland, and water vapour flux

Type:

model:article and TEXT

Format:

bez média and svazek

Description:

Carbon and water fluxes in a semiarid shrubland ecosystem located in the southeast of Spain (province of Almería) were measured continuously over one year using the eddy covariance technique. We examined the influence of environmental variables on daytime (photosynthetically active photons, FP >10 µmol m-2 s-1) ecosystem gas exchange and tested the ability of an empirical eco-physiological model based on FP to estimate carbon fluxes over the whole year. The daytime ecosystem fluxes showed strong seasonality. During two solstitial periods, summer with warm temperatures (>15 °C) and sufficient soil moisture (>10 % vol.) and winter with mild temperatures (>5 °C) and high soil moisture contents (>15 % vol.), the photosynthetic rate was higher than the daytime respiration rate and mean daytime CO2 fluxes were ca. -1.75 and -0.60 µmol m-2 s-1, respectively. Daytime evapotranspiration fluxes averaged ca. 2.20 and 0.24 mmol m-2 s-1, respectively. By contrast, in summer and early autumn with warm daytime temperatures (>10 °C) and dry soil (<10 % vol.), and also in mid-winter with near-freezing daytime temperatures the shrubland behaved as a net carbon source (mean daytime CO2 release of ca. 0.60 and 0.20 µmol m-2 s-1, respectively). Furthermore, the comparison of water and carbon fluxes over a week in June 2004 and June 2005 suggests that the timing-rather than amount-of spring rainfall may be crucial in determining growing season water and carbon exchange. Due to strongly limiting environmental variables other than FP, the model applied here failed to describe daytime carbon exchange only as a function of FP and could not be used over most of the year to fill gaps in the data. and P. Serrano-Ortiz ... [et al.].

Language:

Multiple languages

Rights:

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

Coverage:

30-35

Source:

Photosynthetica | 2007 Volume:45 | Number:1

Harvested from:

CDK

Metadata only:

false