TY - JOUR

T1 - Modeling the environmental response of leaf net photosynthesis in Pinus pinea L. natural regeneration

AU - Calama, R.

AU - Puertolas Simon, Jaime

AU - Madrigal, G.

AU - Pardos, Marta

PY - 2013

Y1 - 2013

N2 - Environmental factors as incident light, temperature and soil water content mainly determine the dynamics of growth and survival of natural forest regeneration in Mediterranean forests. The complex interactions among these factors highlight the need for physiology-based models which describe seedling and sapling performance under current and changing climatic conditions. These models should be flexible enough to take into account the effect of growth light environment changes on physiological processes and, therefore, to assist in the decision-making process on different silvicultural management alternatives under climatic uncertainty. In the present work the net photosynthesic rate of Pinus pinea L. natural regeneration is modeled as a function of light irradiance using the non-rectangular hyperbola function. The model fit was carried out following a two-step procedure, where the parameters of the original function were expanded over the most influential factors: leaf temperature, soil moisture, global site factor and needle type. The developed model allows defining the optimal niche conditions for the natural regeneration of the species and permits identifying the most limiting conditions which prevent natural regeneration. Regeneration niche was assessed by using the model to simulate net CO2 assimilation of a seedling over twelve contrasting light environments during both a normal and an extremely dry vegetative period. The model predicts that the most favorable carbon balance would be found in mid-shaded expositions, while fully exposed plants at midday during summer would exhibit longer periods of negative assimilation rates, especially on severe dry years.

AB - Environmental factors as incident light, temperature and soil water content mainly determine the dynamics of growth and survival of natural forest regeneration in Mediterranean forests. The complex interactions among these factors highlight the need for physiology-based models which describe seedling and sapling performance under current and changing climatic conditions. These models should be flexible enough to take into account the effect of growth light environment changes on physiological processes and, therefore, to assist in the decision-making process on different silvicultural management alternatives under climatic uncertainty. In the present work the net photosynthesic rate of Pinus pinea L. natural regeneration is modeled as a function of light irradiance using the non-rectangular hyperbola function. The model fit was carried out following a two-step procedure, where the parameters of the original function were expanded over the most influential factors: leaf temperature, soil moisture, global site factor and needle type. The developed model allows defining the optimal niche conditions for the natural regeneration of the species and permits identifying the most limiting conditions which prevent natural regeneration. Regeneration niche was assessed by using the model to simulate net CO2 assimilation of a seedling over twelve contrasting light environments during both a normal and an extremely dry vegetative period. The model predicts that the most favorable carbon balance would be found in mid-shaded expositions, while fully exposed plants at midday during summer would exhibit longer periods of negative assimilation rates, especially on severe dry years.

KW - Non-rectangular hyperbola model

KW - Net assimilation rate

KW - Physiological model

KW - Leaf respiration

KW - Ecological niche

U2 - 10.1016/j.ecolmodel.2012.11.029

DO - 10.1016/j.ecolmodel.2012.11.029

M3 - Journal article

VL - 251

SP - 9

EP - 21

JO - Ecological Modelling

JF - Ecological Modelling

SN - 0304-3800

ER -