Drought stress and fluctuating asymmetry in Quercus undulata leaves: confounding effects of absolute and relative amounts of stress?

Fair, Jeanne M.; Breshears, David D.

doi:10.1016/j.jaridenv.2004.11.010

Cited by 40 publications

(36 citation statements)

References 41 publications

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“…Decreased growth is often a more sensitive indicator of stress than is fluctuating asymmetry [205,206]. This is unsurprising because a decline in growth is simultaneously a direct indicator of stress (i.e., stress may dissipate energy away from growth [207]) and a likely adaptive modification maintaining lifetime fitness.…”

Section: Stressmentioning

confidence: 99%

Fluctuating Asymmetry: Methods, Theory, and Applications

et al. 2010

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Fluctuating asymmetry consists of random deviations from perfect symmetry in populations of organisms. It is a measure of developmental noise, which reflects a population's average state of adaptation and coadaptation. Moreover, it increases under both environmental and genetic stress, though responses are often inconsistent. Researchers base studies of fluctuating asymmetry upon deviations from bilateral, radial, rotational, dihedral, translational, helical, and fractal symmetries. Here, we review old and new methods of measuring fluctuating asymmetry, including measures of dispersion, landmark methods for shape asymmetry, and continuous symmetry measures. We also review the theory, developmental origins, and applications of fluctuating asymmetry, and attempt to explain conflicting results. In the process, we present examples from the literature, and from our own research at "Evolution Canyon" and elsewhere.

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Section: Stressmentioning

confidence: 99%

Fluctuating Asymmetry: Methods, Theory, and Applications

et al. 2010

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“…No statistical differences were found between the watered plants in all sampling dates. There were no statistical differences in the water potential of the water-stressed plants, Tsakaldimi et al (2000) and Fair and Breshears (2005) for water-stressed oak plants. Oaks growing with grass had higher water potential than those growing with clover.…”

Section: Methodsmentioning

confidence: 80%

Competitive effects of herbaceous species on water potential and growth of quercus ithaburensis ssp. Macrolepis seedlings

2013

Issue 4

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A noticeable decline of Quercus ithaburensis ssp. Macrolepis, a typical mediterranean species, has been recorded in the past few decades throughout Greece. The triggers were mostly human influences and specifically illegal cuttings, wildfires, and overgrazing. Regeneration and future management of this species is therefore questionable. To investigate the effect of companion plants on this decline as expressed by water availability and plant growth, a pot experiment was conducted and oak seedlings were planted with Bromus sterilis and a mixture of Trifolium repens and T. fragiferum as companion plants. Midday water potential from May to September and oak growth at the end of the experiment were measured as factors affecting oak physiology. The results suggest a different effect on the water potential of the oak seedlings depending on the companion plant species and the time of the year. The presence of a companion plant that has completed its life cycle by the end of spring may positively influence the water status of oaks during the summer months due to shading and lower soil water evaporation. On the contrary, when the companion plants continue their life cycle in the summer, the negative effect may be continued, specifically during the very dry months. The negative effect of grass on the growth of oaks may be attributed to their shading from the dense grass biomass. It can be concluded that control of competitive vegetation, especially of grasses, is crucial for Quercus ithaburensis ssp. macrolepis regeneration by natural (from acorns) or artificial (with up to one-year-old seedlings) methods. This control is necessary at least in the first year after establishment, when seedling height is less than that of the competitive vegetation. If the latter can not be removed by some ways (e.g. controlled grazing), then it is safer to use taller oak seedlings of an older age in the reforestation projects.

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“…Dicha afirmación se genera a partir de las marcadas diferencias que se presentan en estos indicadores morfométricos, cuando los individuos de G. arborea se someten a condiciones contrastantes de humedad del suelo. Esto es afín con los resultados encontrados para Argania spinosa y Quercus undulata, en estudios realizados por Alados & Aich (2008) y Fair & Breshears (2005), en bosques mediterráneos que presentan equivalencia ecológica con los bosques secos tropicales.…”

Section: Discussionunclassified

“…Entre estas se registraron el perímetro foliar (P) y área foliar (ARF), medidas con los analizadores LI-3000C Portable Area Meter y CI-200 Laser Leaf Area Meter, cuyas lecturas se registraron en cm y cm 2 , respectivamente. Peso de la materia seca de la lámina foliar (DWF), registrada en balanza digital con aproximación a miligramos; área foliar específica (AFE), generada a partir de la relación entre el área de la lámina foliar y su respectivo peso de materia seca expresada en metros cuadrados por kilogramo (Fair & Breshears, 2005).…”

Section: Variablesunclassified

INDICADORES MORFOMÉTRICOS FOLIARES PARA LA DETECCIÓN TEMPRANA DEL ESTRÉS HÍDRICO DE Gmelina arborea Roxb. EN SISTEMAS AGROFORESTALES, SANTAFÉ DE ANTIOQUIA

2012

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Palabras clave: asimetría foliar, bosque seco tropical, fenotipo foliar, inestabilidad del desarrollo.Key words: leaf asymmetry, tropical dry forest, leaf phenotype, developmental instability. Artículo de investigación RESUMENEn esta investigación se evaluó la asimetría foliar (ASF) en individuos de Gmelina arbórea Roxb., establecidos en sistemas agroforestales (SAF), en áreas de bosque seco tropical, en el municipio de Santafé de Antioquia. Estos individuos crecen bajo diferentes condiciones hídricas del suelo. La ASF se correlacionó con nuevos parámetros de tipo morfométrico como el ángulo de inserción del peciolo en la lámina foliar (AIP) en individuos maduros y la razón entre el número de dientes del borde de la lámina (RDF) en las hojas de individuos juveniles, propuestos como nuevos indicadores del estado temprano de estrés en la especie. Los modelos generados presentaron valores de R 2 superiores al 75 %, lo que soporta su utilización como indicadores tempranos del estrés hídrico en G. arborea. Adicionalmente, se evaluó la diversidad foliar entre los dos tipos de hojas (HM y HJ), con variables morfométricas convencionales, tales como la longitud de la nervadura principal (L), perímetro de la hoja (P), área foliar específica (AFE) y materia seca (DW), puesto que son caracteres relacionados con la forma y funcionalidad foliar. De lo anterior se dedujo que existen marcadas diferencias en forma y comportamiento entre los dos tipos de hojas. Los resultados de este trabajo permitirán la optimización de estrategias de manejo de G. arborea en el SAF, gracias a la identificación temprana de la presencia de este tipo de estrés. Esto permitiría mantener permanentemente el dosel de los árboles y así mejorar el ambiente de productividad de los cultivos agrícolas asociados. ABSTRACTLeaf asymmetry was assessed in individuals of Gmelina arborea Roxb. growing under different soil water conditions in a dry forest agroforestry system (AFS), in Santafé de Antioquia. Leaf asymmetry was correlated with additional morphometric parameters, such as angle of insertion of the petiole in the leaf in mature individuals and the ratio of the number of teeth on the edge of the blade in juvenile leaves to propose new indicators of early stage stress. The models generated had R 2 values of above 75 %, which support their use in identifying developmental instability as an early indicator of water stress. Similarly, leaf diversity was assessed between the two phenotypes of leaves (ML and JL), with conventional morphometric variables (length of the midrib, leaf perimeter, specific leaf area and dry matter), because they are characters related to leaf form and function. There were

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Drought stress and fluctuating asymmetry in Quercus undulata leaves: confounding effects of absolute and relative amounts of stress?

Cited by 40 publications

References 41 publications

Fluctuating Asymmetry: Methods, Theory, and Applications

Fluctuating Asymmetry: Methods, Theory, and Applications

Competitive effects of herbaceous species on water potential and growth of quercus ithaburensis ssp. Macrolepis seedlings

INDICADORES MORFOMÉTRICOS FOLIARES PARA LA DETECCIÓN TEMPRANA DEL ESTRÉS HÍDRICO DE Gmelina arborea Roxb. EN SISTEMAS AGROFORESTALES, SANTAFÉ DE ANTIOQUIA

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