Ecophysiological modelling of leaf level photosynthetic performance for three Mediterranean species with different growth forms

Abstract

A leaf gross photosynthesis (A) model for three Mediterranean species from different functional groups (the evergreen sclerophyll Arbutus unedo L., the deciduous tree Quercus frainetto Ten. and the semi-deciduous shrub Phlomis fruticosa L.) has been developed through a 3-year seasonal study of gas exchange and plant ecophysiological parameters. The model estimates photosynthesis through four easily measured ecophysiological parameters (chlorophyll content, leaf mass per area (LMA), pre-dawn water potential, leaf temperature) and two meteorological parameters (PAR and average temperature of the 33-day period before measurement (T33)), with a coefficient of determination r2 = 0.88 (P < 0.001). The enhanced accuracy of the presented model may be ascribed to the incorporation of (i) water potential effects on A and (ii) temperature effects on A not only in the short term, but also in the long term (acclimation). Water potential and temperature effects may be considered especially important for species of Mediterranean ecosystems, where strong seasonal variation of these parameters often have a major role in plant growth and survival.

Cultivating the Mediterranean Wild Edible Species Cichorium spinosum L. in Aquaponics: Functional and Growth Responses to Minimal Nutrient Supplementation

“…A standard protocol for the transition from high to zero light intensity was followed including 10steps, notably 1000, 800, 600, 400, 200, 100, 80, 50, 20 and 0 µmol m −2 s −1 , with a duration of 3 min each. The data were analyzed by a modified non-rectangular hyperbola proposed by Markos and Kyparissis [24], through which the maximum photosynthetic rate (A max ), quantum yield of photosynthesis (a, mole CO 2 per mole PAR incident on the surface of the leaf) and dark respiration (Rd) were estimated.…”

sCASE: A primary productivity monitoring system for the forests of North Pindus National Park (Epirus, Greece)

“…Field measured Ψ values in August 2013 are at relatively high levels in the F. sylvatica and P. nigra study sites (-1.24 and -1.45 MPa respectively), while the Quercus species presented lower Ψ values (-2.92 MPa), indicative of water stress conditions [Iovi et al, 2009]. Moreover, Α leaf field measurements in the same day gave an average of 5.51 μmol CO 2 m -2 s -1 for the Quercus species, that normally reach a photosynthetic rate of 15 -20 μmol CO 2 m -2 s -1 [Markos and Kyparissis, 2011]. Therefore, sCASE W scalar estimates for August 2013 are in accordance with Ψ and Α leaf field measurements that were conducted during this period.…”

“…About 8 to 10 samples from the outer part of the canopy and randomly distributed along the site were wrapped in aluminum foil and sealed in plastic bags for 10 minutes and then cut and measured immediately with the pressure chamber. Canopy photosynthesis modeling A leaf measurements were used to parameterize a leaf level photosynthesis model for the 4 dominant forest species of the Park (Fagus sylvatica, Quercus frainetto, Quercus cerris, Pinus nigra) [Markos and Kyparissis, 2011;Markos et al, 2014;Stagakis et al, 2014]. The leaf photosynthesis model is combined with a multi-layer canopy integration model [Spitters, 1986;Leuning et al, 1995;dePury and Farquhar, 1997;Markos, 2013].…”