Partial compensation in Psychotria marginata (Rubiaceae) after simulated defoliation increases photon capture and photosynthesis

Title:

Partial compensation in Psychotria marginata (Rubiaceae) after simulated defoliation increases photon capture and photosynthesis

Creator:

Gálvez, D. and Cohen-Fernández, A.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:2f5d948d-7aee-46db-beb8-0fb07f4203e7
uuid:2f5d948d-7aee-46db-beb8-0fb07f4203e7
issn:0300-3604
doi:10.1007/s11099-005-0157-0

Subject:

computer modelling, daily carbon gain, and photo capture

Type:

model:article and TEXT

Format:

bez média and svazek

Description:

We used Y-plant, a computer-based model of plant crown architecture analysis, to simulate effects of defoliation on daily canopy carbon gain in Psychotria marginata (Rubiaceae) plants under two contrasting irradiances. Five levels of defoliation were simulated using two different types of leaf blade damage. Compensatory increases in photon-saturated photosynthetic capacity (Pmax) of 25, 50, and 100 % defoliation were also simulated. In all simulations daily photon capture and CO2 assimilation increased with defoliation. However, without a compensatory response, daily canopy carbon gain also decreased with defoliation. Under high irradiance, reduction in daily canopy carbon gain was less than what would be expected if the response was proportional to leaf area reduction. Thus, 25 and 50 % defoliation resulted in only 20 and 41 % of daily canopy carbon gain reduction, respectively. In the scenario where 25 % of the leaf area was removed, if the Pmax value was increased by 25 %, the remaining leaves compensated for 94 % of the daily canopy carbon relative to an undamaged non-compensated plant. At the same defoliation level, incrementing Pmax values by 50 and 100 % resulted in overcompensation. Hence, because the increment of daily photon capture and CO2 assimilation after defoliation was more a passive consequence of the reduction in leaf area than an active response, under the conditions tested photosynthetic compensation could be only possible through an active mechanism such as the increment of Pmax values. and D. Gálvez, A. Cohen-Fernández.

Language:

Multiple languages

Rights:

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

Coverage:

46-52

Source:

Photosynthetica | 2006 Volume:44 | Number:1

Harvested from:

CDK

Metadata only:

false