Drought-related tree mortality is a global phenomenon that currently affects a wide range of fore... more Drought-related tree mortality is a global phenomenon that currently affects a wide range of forests. Key functional variables on plant hydraulics, carbon economy, growth and allocation have been identified and play a role in tree drought responses. However, tree mortality thresholds based on such variables are difficult to identify, especially under field conditions. We studied several Aleppo pine populations differently affected by an extreme drought event in 2014, with mortality rates ranging from no mortality to 90% in the most severely affected population. We hypothesized that mortality is linked with high levels of xylem embolism, i.e., hydraulic dysfunction, which would also lead to lower tree resistance to drought in subsequent years. Despite not finding any differences among populations in the vulnerability curves to xylem embolism, there were large differences in the hydraulic safety margin (HSM) and the hydraulic dysfunction level. High mortality rates were associated wit...
Cavitation, stomatal conductance, and leaf dieback in seedlings of two co-occurring Mediterranean... more Cavitation, stomatal conductance, and leaf dieback in seedlings of two co-occurring Mediterranean shrubs during an intense drought
Management strategies, using thinning combined or not combined with underplanting, have been test... more Management strategies, using thinning combined or not combined with underplanting, have been tested in experimental forests of Spain and southern France to promote growth, recruitment and increase their resilience. In dry and fire-prone areas of southern Spain and France, Pinus halepensis forests were thinned at different levels and hardwood species were introduced under pine canopy and in opened areas. Thinning activities increased light, modified microclimate and soil moisture availability. Growth was improved in all sites but survival showed a more contrasted response. In mountainous areas, thinning treatments applied on Abies alba forests of southern France and Pinus nigra forests of central Spain were tested. Thinned silver fir stands showed higher tree growth than the control stands. In black pine forests, maximal seedling emergence was found for high basal area values whereas survival and growth were the highest for lower values. Despite strong site differences, thinning to a...
Este trabajo que se esta desarrollando esta financiado dentro del marco de los proyectos Alteracl... more Este trabajo que se esta desarrollando esta financiado dentro del marco de los proyectos Alteraclim (CGL2015-69773-C2-1-P) y Survive-2 (CGL2015-69773-C2-2-P) con fondos del ministerio de Ciencia y Tecnologia (MINECO/FEDER).
In occidental Europe, Spain is one of countries the most severely affected by desertification (Ar... more In occidental Europe, Spain is one of countries the most severely affected by desertification (Arnalds & Arsher 2000). Particularly, South-eastern Spain is considered as one of the most threatened areas by desertification in Mediterranean Europe (Vallejo 1997). In 2003, the Valencia Regional Forest Service implemented a restoration demonstration project in this area. The project site is a small catchment (25 ha) located in the Albatera municipality. The catchment is highly heterogeneous, with terraced slopes, south-facing slopes and north-facing slopes. The restoration strategy was based on planting evergreen trees and shrubs which can grow quickly after disturbances, and on field treatments aimed at maximizing water collection (micro-catchments, planting furrows), organic amendment (compost), and conservation (tree shelters, mulching). On south landscape unit, the whole category of restoration treatments was applied : water micro-catchment + Tubex tree shelters + mulching & compost...
El objetivo del presente trabajo fue determinar el balance hídrico del suelo en bosques de pino c... more El objetivo del presente trabajo fue determinar el balance hídrico del suelo en bosques de pino carrasco con diferente densidad de arbolado utilizando el modelo ecohidrológico HYDROBAL, y evaluar sus efectos sobre la introducción y establecimiento bajo el dosel, de brinzales de especies ampliamente utilizadas en la restauración forestal. En este contexto, en La Hunde (Ayora, Valencia), y como consecuencia de previas labores de aclareo con diferente intensidad, se definieron tres tratamientos experimentales de acuerdo a diferentes densidades de pinos: Baja (100-300 pies ha -1 ); Media (300-700 pies ha -1 ) y Alta (700-1100 pies ha 1 ). De cada tratamiento se establecieron tres parcelas experimentales de 900 m 2 , localizadas en tres sitios (El Aljibe, El Lobo y El Mojón). En cada parcela se plantaron quince individuos de seis especies rebrotadoras con características morfo-funcionales contrastadas (Arbutus unedo, Rhamnus alaternus, Quercus ilex, Quercus faginea, Fraxinus ornus, Acer ...
Heavy metal contamination and drought are expected to increase in large areas worldwide. However,... more Heavy metal contamination and drought are expected to increase in large areas worldwide. However, their combined effect on plant performance has been scantly analyzed. This study examines the effect of Zn supply at different water availabilities on morpho‐physiological traits of Quercus suber L. in order to analyze the combined effects of both stresses. Seedlings were treated with four levels of zinc from 3 to 150 µM and exposed to low watering (LW) or high watering (HW) frequency in hydroponic culture, using a growth chamber. Under both watering regimes, Zn concentration in leaves and roots increased with Zn increment in nutrient solution. Nevertheless, at the highest Zn doses, Zn tissue concentrations were almost twice in HW than in LW seedlings. Functional traits as leaf photosynthetic rate and root hydraulic conductivity, and morphological traits as root length and root biomass decreased significantly in response to Zn supply. Auxin levels increased with Zn concentrations, sugge...
Drought-related tree mortality is a global phenomenon that currently affects a wide range of fore... more Drought-related tree mortality is a global phenomenon that currently affects a wide range of forests. Key functional variables on plant hydraulics, carbon economy, growth and allocation have been identified and play a role in tree drought responses. However, tree mortality thresholds based on such variables are difficult to identify, especially under field conditions. We studied several Aleppo pine populations differently affected by an extreme drought event in 2014, with mortality rates ranging from no mortality to 90% in the most severely affected population. We hypothesized that mortality is linked with high levels of xylem embolism, i.e., hydraulic dysfunction, which would also lead to lower tree resistance to drought in subsequent years. Despite not finding any differences among populations in the vulnerability curves to xylem embolism, there were large differences in the hydraulic safety margin (HSM) and the hydraulic dysfunction level. High mortality rates were associated wit...
Cavitation, stomatal conductance, and leaf dieback in seedlings of two co-occurring Mediterranean... more Cavitation, stomatal conductance, and leaf dieback in seedlings of two co-occurring Mediterranean shrubs during an intense drought
Management strategies, using thinning combined or not combined with underplanting, have been test... more Management strategies, using thinning combined or not combined with underplanting, have been tested in experimental forests of Spain and southern France to promote growth, recruitment and increase their resilience. In dry and fire-prone areas of southern Spain and France, Pinus halepensis forests were thinned at different levels and hardwood species were introduced under pine canopy and in opened areas. Thinning activities increased light, modified microclimate and soil moisture availability. Growth was improved in all sites but survival showed a more contrasted response. In mountainous areas, thinning treatments applied on Abies alba forests of southern France and Pinus nigra forests of central Spain were tested. Thinned silver fir stands showed higher tree growth than the control stands. In black pine forests, maximal seedling emergence was found for high basal area values whereas survival and growth were the highest for lower values. Despite strong site differences, thinning to a...
Este trabajo que se esta desarrollando esta financiado dentro del marco de los proyectos Alteracl... more Este trabajo que se esta desarrollando esta financiado dentro del marco de los proyectos Alteraclim (CGL2015-69773-C2-1-P) y Survive-2 (CGL2015-69773-C2-2-P) con fondos del ministerio de Ciencia y Tecnologia (MINECO/FEDER).
In occidental Europe, Spain is one of countries the most severely affected by desertification (Ar... more In occidental Europe, Spain is one of countries the most severely affected by desertification (Arnalds & Arsher 2000). Particularly, South-eastern Spain is considered as one of the most threatened areas by desertification in Mediterranean Europe (Vallejo 1997). In 2003, the Valencia Regional Forest Service implemented a restoration demonstration project in this area. The project site is a small catchment (25 ha) located in the Albatera municipality. The catchment is highly heterogeneous, with terraced slopes, south-facing slopes and north-facing slopes. The restoration strategy was based on planting evergreen trees and shrubs which can grow quickly after disturbances, and on field treatments aimed at maximizing water collection (micro-catchments, planting furrows), organic amendment (compost), and conservation (tree shelters, mulching). On south landscape unit, the whole category of restoration treatments was applied : water micro-catchment + Tubex tree shelters + mulching & compost...
El objetivo del presente trabajo fue determinar el balance hídrico del suelo en bosques de pino c... more El objetivo del presente trabajo fue determinar el balance hídrico del suelo en bosques de pino carrasco con diferente densidad de arbolado utilizando el modelo ecohidrológico HYDROBAL, y evaluar sus efectos sobre la introducción y establecimiento bajo el dosel, de brinzales de especies ampliamente utilizadas en la restauración forestal. En este contexto, en La Hunde (Ayora, Valencia), y como consecuencia de previas labores de aclareo con diferente intensidad, se definieron tres tratamientos experimentales de acuerdo a diferentes densidades de pinos: Baja (100-300 pies ha -1 ); Media (300-700 pies ha -1 ) y Alta (700-1100 pies ha 1 ). De cada tratamiento se establecieron tres parcelas experimentales de 900 m 2 , localizadas en tres sitios (El Aljibe, El Lobo y El Mojón). En cada parcela se plantaron quince individuos de seis especies rebrotadoras con características morfo-funcionales contrastadas (Arbutus unedo, Rhamnus alaternus, Quercus ilex, Quercus faginea, Fraxinus ornus, Acer ...
Heavy metal contamination and drought are expected to increase in large areas worldwide. However,... more Heavy metal contamination and drought are expected to increase in large areas worldwide. However, their combined effect on plant performance has been scantly analyzed. This study examines the effect of Zn supply at different water availabilities on morpho‐physiological traits of Quercus suber L. in order to analyze the combined effects of both stresses. Seedlings were treated with four levels of zinc from 3 to 150 µM and exposed to low watering (LW) or high watering (HW) frequency in hydroponic culture, using a growth chamber. Under both watering regimes, Zn concentration in leaves and roots increased with Zn increment in nutrient solution. Nevertheless, at the highest Zn doses, Zn tissue concentrations were almost twice in HW than in LW seedlings. Functional traits as leaf photosynthetic rate and root hydraulic conductivity, and morphological traits as root length and root biomass decreased significantly in response to Zn supply. Auxin levels increased with Zn concentrations, sugge...
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