Dark respiration in light as well as in dark was estimated for attached leaves of an evergreen (H... more Dark respiration in light as well as in dark was estimated for attached leaves of an evergreen (Heteromeles arbufifolia Ait.) and a deciduous (Lepechinia fragans Creene) shrub species using an open gas-exchange system. Dark respiration in light was estimated by the Laisk method. Respiration rates in the dark were always higher than in the light, indicating that light inhibited respiration in both species. The rates of respiration in the dark were higher in the leaves of the deciduous species than in the evergreen species. However, there were no significant differences in respiration rates i n light between the species. Thus, the degree of inhibition of respiration by light was greater in the deciduous species (62%) than in the evergreen species (51 %). Respiration in both the light and darkness decreased with increasing leaf age. However, because respiration in the light decreased faster with leaf age than respiration in darkness, the degree of inhibition of respiration by light increased with leaf age (from 36% in the youngest leaves to 81 Yo in the mature leaves). This suggests that the rate of dark respiration in the light i s related to the rate of biosynthetic processes. Dark respiration i n the light decreased with increasing light intensity. Respiration both in the light and i n the dark was dependent on leaf temperature. We concluded that respiration i n light and respiration in darkness are tightly coupled, with variation i n respiration in darkness accounting for more than 60% of the variation in respiration in light. Care must be taken when the relation between respiration in light and respiration in darkness is studied, because the relation varies with species, leaf age, and light intensity.
Leaf mass per area (LMA) is a morphological trait widely used as a good indicator of plant functi... more Leaf mass per area (LMA) is a morphological trait widely used as a good indicator of plant functioning (i.e. photosynthetic and respiratory rates, chemical composition, resistance to herbivory, etc.). The LMA can be broken down into the leaf density (LD) and leaf volume to area ratio (LVA or thickness), which in turn are determined by anatomical tissues and chemical composition. The aim of this study is to understand the anatomical and chemical characteristics related to LMA variation in species growing in the field along a water availability gradient. We determined LMA and its components (LD, LVA and anatomical tissues) for 34 Mediterranean (20 evergreen and 14 deciduous) woody species. Variation in LMA was due to variation in both LD and LVA. For both deciduous and evergreen species LVA variation was strongly and positively related with mesophyll volume per area (VA or thickness), but for evergreen species positive relationships of LVA with the VA of epidermis, vascular plus sclerenchyma tissues and air spaces were found as well. The leaf carbon concentration was positively related with mesophyll VA in deciduous species, and with VA of vascular plus sclerenchymatic tissues in evergreens. Species occurring at the sites with lower water availability were generally characterised by a high LMA and LD.
Extreme climatic episodes, likely associated with climate change, often result in profound altera... more Extreme climatic episodes, likely associated with climate change, often result in profound alterations of ecosystems and, particularly, in drastic events of vegetation die-off. Species attributes are expected to explain different biological responses to these environmental alterations. Here we explored how changes in plant cover and recruitment in response to an extreme climatic episode of drought and low temperatures were related to a set of functional traits (of leaves, roots and seeds) in Mediterranean shrubland species of south-west Spain. Remaining aerial green cover 2 years after the climatic event was positively related to specific leaf area (SLA), and negatively to leaf water potential, stable carbon isotope ratio and leaf proline content. However, plant cover resilience, i.e. the ability to attain pre-event values, was positively related to a syndrome of traits distinguished by a higher efficiency of water use and uptake. Thus, higher SLA and lower water-use efficiency characterized species that were able to maintain green biomass for a longer period of time but were less resilient in the medium term. There was a negative relationship between such syndromes and the number of emerging seedlings. Species with small seeds produced more seedlings per adult. Overall, recruitment was positively correlated with species die-off. This study demonstrates the relationship between plant traits and strong environmental pulses related to climate change, providing a functional interpretation of the recently reported episodes of climate-induced vegetation die-off. Our findings reveal the importance of selecting meaningful traits to interpret post-event resilience processes, particularly when combined with demographic attributes.
Cuadernos De La Sociedad Espanola De Ciencias Forestales, 2005
Page 1. ANÁLISIS DEL CRECIMIENTO DE PLÁNTULAS DE QUERCUS SUBER Y Q. CANARIENSIS: EXPERIMENTOS DE ... more Page 1. ANÁLISIS DEL CRECIMIENTO DE PLÁNTULAS DE QUERCUS SUBER Y Q. CANARIENSIS: EXPERIMENTOS DE CAMPO Y DE INVERNADERO Teodoro Marañón1, R. Villar2, Jose Luis Quero2,3 y IM Pérez-Ramos1 1 IRNAS. CSIC. Av. Reina Mercedes 10. ...
La mayoría de las repoblaciones forestales se realizan en zonas con poca cobertura vegetal, y, cu... more La mayoría de las repoblaciones forestales se realizan en zonas con poca cobertura vegetal, y, cuando la hay, normalmente se elimina para facilitar las labores de repoblación y para eliminar la competencia por otras plantas. Sin embargo, en algunos estudios se ha comprobado el efecto beneficioso de una cubierta vegetal sobre el crecimiento y supervivencia de las plántulas. Estos efectos podrían venir determinados por diferencias en la tasa de fotosíntesis y en la eficiencia del uso del agua (cociente entre tasa de fotosíntesis y tasa de transpiración). Por ello, hemos estudiado las tasas de fotosíntesis y transpiración y la eficiencia en el uso del agua para dos especies que se distribuyen en el Parque Natural Los Alcornocales: el alcornoque (Q. suber) y el roble melojo (Q. pyrenaica) en tres condiciones distintas: en zonas descubiertas, en zonas bajo cubierta arbórea y en zonas con cubierta densa de bosque. Las intensidades luminosas para las tres zonas fueron muy distintas entre sí, siendo, como cabía esperar, altas en los sitios abiertos, intermedias en los sitios con cobertura arbórea y muy bajas en los de zonas con cubierta de bosque. La respuesta de la tasa de fotosíntesis a la luz fue muy similar para las dos especies y tratamientos, aunque se encontraron diferencias significativas en el punto de compensación a la luz (la luz necesaria para que la ganancia de carbono por fotosíntesis equilibren las pérdidas por respiración). El punto de compensación disminuyó desde los micrositios abiertos a los que estaban bajo cubierta densa de bosque. La respuesta de la fotosíntesis a la luz muestra que para las dos especies una radiación mayor de 600 µmol m -2 seg -1 determina un descenso en la tasa de fotosíntesis (por fotoinhibición), por lo que en las zonas abiertas, este fenómeno se puede producir mucho más a menudo, determinando una menor ganancia de carbono para esas plantas. La ganancia de carbono diaria fue similar entre las plantas de los micrositios abiertos y con cobertura arbórea, y muy pequeña para las plantas de los micrositios de bosque cerrado, debido a la escasa luz que reciben. La eficiencia en el uso del agua nos muestra que las plantas en los micrositios con cubierta arbórea son las más eficientes, esto junto al hecho de que tienen una ganancia de carbono alta, nos sugiere que son los micrositios mejores para la regeneración de las plántulas de estas dos especies.
Respuesta plástica a la luz y al agua en cuatro especies mediterráneas del género Quercus (Fagace... more Respuesta plástica a la luz y al agua en cuatro especies mediterráneas del género Quercus (Fagaceae) Plastic response to light and water in four Mediterranean Quercus species (Fagaceae)
Respuesta plástica a la luz y al agua en cuatro especies mediterráneas del género Quercus (Fagace... more Respuesta plástica a la luz y al agua en cuatro especies mediterráneas del género Quercus (Fagaceae) Plastic response to light and water in four Mediterranean Quercus species (Fagaceae)
Aims Biochar is a carbon-rich product obtained from the pyrolysis of organic materials. Its use, ... more Aims Biochar is a carbon-rich product obtained from the pyrolysis of organic materials. Its use, combined with fertilizers, can modify soil properties and affect root morphology and functioning. The main objective of this study was to evaluate the impact of biochar and fertilizer addition on root development and morphology. Methods Durum wheat was pot-grown for 2 months using two types of biochar (produced from wheat straw and olive-tree pruning) applied at four rates (0, 0.5, 1 and 2.5 % w/w) and combined with three fertilization levels (0, 40 %-low and 100 %-complete).
Dark respiration in the light was estimated in leaves of two woody species (Heteromeles arbutifol... more Dark respiration in the light was estimated in leaves of two woody species (Heteromeles arbutifolia Ait. and Lepechinia fragans Greene) using two different approaches based on gas-exchange techniques: the Kok method and the Laisk method. In all cases, dark respiration in the light was lower (P < 0.05) than respiration in darkness, indicating that dark respiration was inhibited in the light. Rates of dark respiration in the light estimated by the Laisk method were 52% higher (P < 0.05) than those estimated by the Kok method. Differences between the methods could be explained by the low ambient CO2 concentrations required by the Laisk approach. The mean value of the inhibition of respiration by light for the two species, corrected for the ambient CO2 concentration effect, was 55%. Despite the differences in leaf characteristics between the species, values of the CO2 photocompensation point, at which the rate of photosynthetic CO2 uptake equaled that of photorespiratory CO2 evolu...
La superficie forestal de la Península Ibérica está dominada por especies del género Quercus. Sin... more La superficie forestal de la Península Ibérica está dominada por especies del género Quercus. Sin embargo, la regeneración de estos bosques está seriamente limitada por distintos factores, siendo la fase de plántula una de las fases más vulnerables. En este trabajo estudiamos algunos factores claves en el establecimiento de cuatro especies de Quercus (Q. ilex, Q. suber, Q. faginea, Q. pyrenaica) en el P.N. Sierra de Cardeña y Montoro (Córdoba), prestando especial atención a la variabilidad intraespecífica como modulador del éxito en las distintas fases de establecimiento. Para ello, dentro de cada especie, seleccionamos semillas de cinco progenitores, y estudiamos cómo el origen (progenitor) y distintos factores ambientales afectan a las fases de emergencia, crecimiento y supervivencia en los primeros años de vida. Nuestros resultados indican que el progenitor introduce diferencias importantes en las fases de establecimiento y en el crecimiento. Además, el progenitor modifica la respuesta a los factores ambientales o al propio peso de la semilla en diferentes fases del establecimiento, pudiendo ser este efecto de importancia en ambientes heterogéneos como el mediterráneo y en un escenario de cambio climático. Nuestros resultados sugieren la importancia del mantenimiento de la diversidad genética en las actuaciones de restauración para la persistencia de los bosques mediterráneos.
Go to AGRIS search. Vegetation response to climatic change in a dune ecosystem in southern Spain.... more Go to AGRIS search. Vegetation response to climatic change in a dune ecosystem in southern Spain. ...
Dark respiration in light as well as in dark was estimated for attached leaves of an evergreen (H... more Dark respiration in light as well as in dark was estimated for attached leaves of an evergreen (Heteromeles arbufifolia Ait.) and a deciduous (Lepechinia fragans Creene) shrub species using an open gas-exchange system. Dark respiration in light was estimated by the Laisk method. Respiration rates in the dark were always higher than in the light, indicating that light inhibited respiration in both species. The rates of respiration in the dark were higher in the leaves of the deciduous species than in the evergreen species. However, there were no significant differences in respiration rates i n light between the species. Thus, the degree of inhibition of respiration by light was greater in the deciduous species (62%) than in the evergreen species (51 %). Respiration in both the light and darkness decreased with increasing leaf age. However, because respiration in the light decreased faster with leaf age than respiration in darkness, the degree of inhibition of respiration by light increased with leaf age (from 36% in the youngest leaves to 81 Yo in the mature leaves). This suggests that the rate of dark respiration in the light i s related to the rate of biosynthetic processes. Dark respiration i n the light decreased with increasing light intensity. Respiration both in the light and i n the dark was dependent on leaf temperature. We concluded that respiration i n light and respiration in darkness are tightly coupled, with variation i n respiration in darkness accounting for more than 60% of the variation in respiration in light. Care must be taken when the relation between respiration in light and respiration in darkness is studied, because the relation varies with species, leaf age, and light intensity.
Leaf mass per area (LMA) is a morphological trait widely used as a good indicator of plant functi... more Leaf mass per area (LMA) is a morphological trait widely used as a good indicator of plant functioning (i.e. photosynthetic and respiratory rates, chemical composition, resistance to herbivory, etc.). The LMA can be broken down into the leaf density (LD) and leaf volume to area ratio (LVA or thickness), which in turn are determined by anatomical tissues and chemical composition. The aim of this study is to understand the anatomical and chemical characteristics related to LMA variation in species growing in the field along a water availability gradient. We determined LMA and its components (LD, LVA and anatomical tissues) for 34 Mediterranean (20 evergreen and 14 deciduous) woody species. Variation in LMA was due to variation in both LD and LVA. For both deciduous and evergreen species LVA variation was strongly and positively related with mesophyll volume per area (VA or thickness), but for evergreen species positive relationships of LVA with the VA of epidermis, vascular plus sclerenchyma tissues and air spaces were found as well. The leaf carbon concentration was positively related with mesophyll VA in deciduous species, and with VA of vascular plus sclerenchymatic tissues in evergreens. Species occurring at the sites with lower water availability were generally characterised by a high LMA and LD.
Extreme climatic episodes, likely associated with climate change, often result in profound altera... more Extreme climatic episodes, likely associated with climate change, often result in profound alterations of ecosystems and, particularly, in drastic events of vegetation die-off. Species attributes are expected to explain different biological responses to these environmental alterations. Here we explored how changes in plant cover and recruitment in response to an extreme climatic episode of drought and low temperatures were related to a set of functional traits (of leaves, roots and seeds) in Mediterranean shrubland species of south-west Spain. Remaining aerial green cover 2 years after the climatic event was positively related to specific leaf area (SLA), and negatively to leaf water potential, stable carbon isotope ratio and leaf proline content. However, plant cover resilience, i.e. the ability to attain pre-event values, was positively related to a syndrome of traits distinguished by a higher efficiency of water use and uptake. Thus, higher SLA and lower water-use efficiency characterized species that were able to maintain green biomass for a longer period of time but were less resilient in the medium term. There was a negative relationship between such syndromes and the number of emerging seedlings. Species with small seeds produced more seedlings per adult. Overall, recruitment was positively correlated with species die-off. This study demonstrates the relationship between plant traits and strong environmental pulses related to climate change, providing a functional interpretation of the recently reported episodes of climate-induced vegetation die-off. Our findings reveal the importance of selecting meaningful traits to interpret post-event resilience processes, particularly when combined with demographic attributes.
Cuadernos De La Sociedad Espanola De Ciencias Forestales, 2005
Page 1. ANÁLISIS DEL CRECIMIENTO DE PLÁNTULAS DE QUERCUS SUBER Y Q. CANARIENSIS: EXPERIMENTOS DE ... more Page 1. ANÁLISIS DEL CRECIMIENTO DE PLÁNTULAS DE QUERCUS SUBER Y Q. CANARIENSIS: EXPERIMENTOS DE CAMPO Y DE INVERNADERO Teodoro Marañón1, R. Villar2, Jose Luis Quero2,3 y IM Pérez-Ramos1 1 IRNAS. CSIC. Av. Reina Mercedes 10. ...
La mayoría de las repoblaciones forestales se realizan en zonas con poca cobertura vegetal, y, cu... more La mayoría de las repoblaciones forestales se realizan en zonas con poca cobertura vegetal, y, cuando la hay, normalmente se elimina para facilitar las labores de repoblación y para eliminar la competencia por otras plantas. Sin embargo, en algunos estudios se ha comprobado el efecto beneficioso de una cubierta vegetal sobre el crecimiento y supervivencia de las plántulas. Estos efectos podrían venir determinados por diferencias en la tasa de fotosíntesis y en la eficiencia del uso del agua (cociente entre tasa de fotosíntesis y tasa de transpiración). Por ello, hemos estudiado las tasas de fotosíntesis y transpiración y la eficiencia en el uso del agua para dos especies que se distribuyen en el Parque Natural Los Alcornocales: el alcornoque (Q. suber) y el roble melojo (Q. pyrenaica) en tres condiciones distintas: en zonas descubiertas, en zonas bajo cubierta arbórea y en zonas con cubierta densa de bosque. Las intensidades luminosas para las tres zonas fueron muy distintas entre sí, siendo, como cabía esperar, altas en los sitios abiertos, intermedias en los sitios con cobertura arbórea y muy bajas en los de zonas con cubierta de bosque. La respuesta de la tasa de fotosíntesis a la luz fue muy similar para las dos especies y tratamientos, aunque se encontraron diferencias significativas en el punto de compensación a la luz (la luz necesaria para que la ganancia de carbono por fotosíntesis equilibren las pérdidas por respiración). El punto de compensación disminuyó desde los micrositios abiertos a los que estaban bajo cubierta densa de bosque. La respuesta de la fotosíntesis a la luz muestra que para las dos especies una radiación mayor de 600 µmol m -2 seg -1 determina un descenso en la tasa de fotosíntesis (por fotoinhibición), por lo que en las zonas abiertas, este fenómeno se puede producir mucho más a menudo, determinando una menor ganancia de carbono para esas plantas. La ganancia de carbono diaria fue similar entre las plantas de los micrositios abiertos y con cobertura arbórea, y muy pequeña para las plantas de los micrositios de bosque cerrado, debido a la escasa luz que reciben. La eficiencia en el uso del agua nos muestra que las plantas en los micrositios con cubierta arbórea son las más eficientes, esto junto al hecho de que tienen una ganancia de carbono alta, nos sugiere que son los micrositios mejores para la regeneración de las plántulas de estas dos especies.
Respuesta plástica a la luz y al agua en cuatro especies mediterráneas del género Quercus (Fagace... more Respuesta plástica a la luz y al agua en cuatro especies mediterráneas del género Quercus (Fagaceae) Plastic response to light and water in four Mediterranean Quercus species (Fagaceae)
Respuesta plástica a la luz y al agua en cuatro especies mediterráneas del género Quercus (Fagace... more Respuesta plástica a la luz y al agua en cuatro especies mediterráneas del género Quercus (Fagaceae) Plastic response to light and water in four Mediterranean Quercus species (Fagaceae)
Aims Biochar is a carbon-rich product obtained from the pyrolysis of organic materials. Its use, ... more Aims Biochar is a carbon-rich product obtained from the pyrolysis of organic materials. Its use, combined with fertilizers, can modify soil properties and affect root morphology and functioning. The main objective of this study was to evaluate the impact of biochar and fertilizer addition on root development and morphology. Methods Durum wheat was pot-grown for 2 months using two types of biochar (produced from wheat straw and olive-tree pruning) applied at four rates (0, 0.5, 1 and 2.5 % w/w) and combined with three fertilization levels (0, 40 %-low and 100 %-complete).
Dark respiration in the light was estimated in leaves of two woody species (Heteromeles arbutifol... more Dark respiration in the light was estimated in leaves of two woody species (Heteromeles arbutifolia Ait. and Lepechinia fragans Greene) using two different approaches based on gas-exchange techniques: the Kok method and the Laisk method. In all cases, dark respiration in the light was lower (P < 0.05) than respiration in darkness, indicating that dark respiration was inhibited in the light. Rates of dark respiration in the light estimated by the Laisk method were 52% higher (P < 0.05) than those estimated by the Kok method. Differences between the methods could be explained by the low ambient CO2 concentrations required by the Laisk approach. The mean value of the inhibition of respiration by light for the two species, corrected for the ambient CO2 concentration effect, was 55%. Despite the differences in leaf characteristics between the species, values of the CO2 photocompensation point, at which the rate of photosynthetic CO2 uptake equaled that of photorespiratory CO2 evolu...
La superficie forestal de la Península Ibérica está dominada por especies del género Quercus. Sin... more La superficie forestal de la Península Ibérica está dominada por especies del género Quercus. Sin embargo, la regeneración de estos bosques está seriamente limitada por distintos factores, siendo la fase de plántula una de las fases más vulnerables. En este trabajo estudiamos algunos factores claves en el establecimiento de cuatro especies de Quercus (Q. ilex, Q. suber, Q. faginea, Q. pyrenaica) en el P.N. Sierra de Cardeña y Montoro (Córdoba), prestando especial atención a la variabilidad intraespecífica como modulador del éxito en las distintas fases de establecimiento. Para ello, dentro de cada especie, seleccionamos semillas de cinco progenitores, y estudiamos cómo el origen (progenitor) y distintos factores ambientales afectan a las fases de emergencia, crecimiento y supervivencia en los primeros años de vida. Nuestros resultados indican que el progenitor introduce diferencias importantes en las fases de establecimiento y en el crecimiento. Además, el progenitor modifica la respuesta a los factores ambientales o al propio peso de la semilla en diferentes fases del establecimiento, pudiendo ser este efecto de importancia en ambientes heterogéneos como el mediterráneo y en un escenario de cambio climático. Nuestros resultados sugieren la importancia del mantenimiento de la diversidad genética en las actuaciones de restauración para la persistencia de los bosques mediterráneos.
Go to AGRIS search. Vegetation response to climatic change in a dune ecosystem in southern Spain.... more Go to AGRIS search. Vegetation response to climatic change in a dune ecosystem in southern Spain. ...
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