{"id":102535,"date":"2010-06-07T00:00:00","date_gmt":"2010-06-07T00:00:00","guid":{"rendered":""},"modified":"2010-06-07T00:00:00","modified_gmt":"2010-06-07T00:00:00","slug":"contribution-to-the-ecology-of-the-middle-ebro-riparian-woodlands-implications-for-management-ingles-contribucion-a-la-ecologa%c2%ada-de-los-bosques-riparios-del-ebro-medio-implicaciones-para-la","status":"publish","type":"post","link":"https:\/\/www.deberes.net\/tesis\/ecologia-vegetal\/contribution-to-the-ecology-of-the-middle-ebro-riparian-woodlands-implications-for-management-ingles-contribucion-a-la-ecologa%c2%ada-de-los-bosques-riparios-del-ebro-medio-implicaciones-para-la\/","title":{"rendered":"Contribution to the ecology of the middle ebro riparian woodlands: implications for management (ingles). contribuci\u00f3n a la ecolog\u00eda de los bosques riparios del ebro medio: implicaciones para la gesti\u00f3n( espa\u00f1ol)"},"content":{"rendered":"<h2>Tesis doctoral de <strong> Eduardo Gonz\u00e1lez Sargas <\/strong><\/h2>\n<p>English version the riparian woodland ecology of one of the largest regulated mediterranean rivers, the ebro river (ne spain), was examined with the ultimate purpose of guiding through future management plans. To that end, some aspects of the tree structure, functioning and functions were explored in relation to their primary driver, the hydrogeomorphic regime, at different spatial and temporal scales. An 8-km river segment representative of the meandering middle ebro reach was selected for all studies. the first task was to study the structure and health of the riparian woodlands at the reach- and patch-scale, within the framework of an 80-year-chronosequence defined according to regulation-induced hydrogeomorphic changes. The changes in the forest structure and species composition were analysed using historical aerial photographs dated in 1927, 1957, 1981 and 2003 and a detailed field survey carried out in 2006 and 2007. The results revealed a dichotomous situation, with pioneer forests limited to narrow bands running parallel to the main channel and in-channel areas, contrasting with generalized senescence in the rest of the floodplain covered by natural vegetation. This situation was caused by a loss of hydrogeomorphic dynamism, and by the deficient replacement of pioneer species (populus nigra, salix alba and tamarix spp.) By late-seral species (fraxinus angustifolia and ulmus minor). In a second step, research was made on two key processes for forest structure dynamics: sexual regeneration and response of mature tree populations to the local hydrological gradient. Seed dispersal, germination and greenhouse studies showed that the sexual regeneration strategies of one of the apparently more negatively species affected by the new hydrogeomorphic regime, p. Alba, were equivalent to those of other pioneer species worldwide, highlighting the potential for forest restoration based on the renaturalization of the hydrogeomorphic regime. The relationship between the mortality rates of p. Alba, p. Nigra, s. Alba and tamarix spp. And the local hydrology was examined in detail after monitoring the water table levels in 2007, 2008 and 2009. All the species exhibited significant relationships, which was interpreted as an evidence of their phreatophytic (i.E., Groundwater dependent) nature. This information was used to propose some hydrologic thresholds for the conservation of their mature populations. Surprisingly, the shift in composition from salicaceae to tamaricaceae spp. With drier conditions, observed in other semi-arid regions of the world, was not detected in the ebro. Only s. Alba significantly lost importance with drier hydroperiods, relative to the other species. the role of leaf nutrient content in riparian trees as indicator of nutrient limitation in forested floodplains was examined to discuss the consequences of possible nutrient use differences on the competition between the two dominant tree genera in semi-arid regions of the world: populus and tamarix. To that end, the seasonal and spatial variability in leaf nitrogen (n) and phosphorus (p) content was analyzed in 720 leaves (2 tree genera x 3 seasons x 12 geomorphic sites x 10 tree replicates). The results showed that tamarix is more variable than populus in terms of leaf n and p content, which seems to support the hypothesis that tamarix is better adapted to low disturbance and high stress scenarios (floodplain stabilization and water and nutrient stress), compared to populus, more effective in high-disturbance and low-stress environments (higher flooding disturbance but water and nutrient availability), which would give a novel explanation to the success of tamarix in regulated rivers. However, these differences were obscured by a stronger spatial component that affected both genera, especially through phosphorus limitation along the flooding gradient, as shown by linear mixed effects (lme) models. In general, at shorter flood durations, n and p loss by trees with litterfall was lower and n:p ratio increased. the response of litter production to hydrologic gradients was also examined, as a key ecological function of the riparian woodlands for the floodplain ecosystem. In 2007, litterfall was monitored monthly in 12 plots covering a variety of forest patches differing in structure, soil and hydroperiod. Lme models and hierarchical partitioning were used to assess the spatial variability in litter production and to explore the relative importance of 17 parameters (representing the forest patch structure, soil, hydroperiod and litterfall chemistry) as potential litter production predictors. The results suggested that, although production in the ebro riparian woodlands (mean = 563 g\u00c2\u00bfm-2\u00c2\u00bfy-1) is medium-to-high compared to global and regional means, p limitation might be reducing it in the outer forest patches due to an insufficient input of nutrient-laden sediments with the lack of overbank floods. Forest structure was responsible for 30% of the explained variability, whereas flooding regime and soil fertility, directly or indirectly by litterfall chemistry parameters, explained the remaining 70%. based on all these results, which highlighted the disturbance-dependency of the middle ebro riparian woodlands, the recovery of some hydrogeomorphic dynamism at different scales (basin, reach and site) is recommended to guarantee the self-sustainability of their structure, functioning and free ecological services that they provide. Hopefully, these recommendations might help to take successful management decisions in other semi-arid and mediterranean watersheds with hydrogeomorphic constraints similar to those of the middle ebro.  keywords: hydrogeomorphic regime, linear mixed effect models (lme), litter production, management, mediterranean river, middle ebro river, nutrient use by riparian trees, n and p leaf content, populus alba, populus nigra, riparian woodland structure, river regulation, salix alba, semi-arid river, senescence, sexual regeneration, tamarix spp. versi\u00f3n en espa\u00f1ol  la ecolog\u00eda de los bosques riparios de uno de los mayores r\u00edos mediterr\u00e1neos regulados, el r\u00edo ebro (ne espa\u00f1a), ha sido examinada con el objetivo final de guiar planes de gesti\u00f3n futuros. A este fin, algunos aspectos de la estructura, funcionamiento y funciones de las formaciones arb\u00f3reas se exploraron en relaci\u00f3n a su principal factor controlador, el r\u00e9gimen hidrogeomorfol\u00f3gico, a diferentes escalas espaciales y temporales. Un segmento de r\u00edo de 8 km representativo del tramo medio del ebro fue seleccionado para todos los estudios. la primera tarea fue estudiar la estructura y salud de los bosques de ribera a las escalas de tramo y parcela, en el marco de una cronosecuencia de 80 a\u00f1os definida seg\u00fan cambios hidrogeomorfol\u00f3gicos inducidos por la regulaci\u00f3n. Los cambios en la estructura forestal y en la composici\u00f3n de especies se analizaron usando fotograf\u00edas a\u00e9reas hist\u00f3ricas fechadas en 1927, 1957, 1981 y 2003 y un detallado estudio de campo ejecutado en 2006 y 2007. Los resultados revelaron una situaci\u00f3n dicot\u00f3mica, con bosques pioneros limitados a estrechas bandas paralelas al cauce principal y a \u00e1reas dentro del propio cauce, en contraste con un envejecimiento generalizado en el resto de la llanura de inundaci\u00f3n cubierta por vegetaci\u00f3n natural. Esta situaci\u00f3n fue causada por una p\u00e9rdida de din\u00e1mica hidrogeomorfol\u00f3gica, y por un reemplazo deficitario de especies pioneras (populus nigra, salix alba y tamarix spp.) Por especies tard\u00edas en la sucesi\u00f3n (fraxinus angustifolia y ulmus minor). En un segundo paso, se investigaron dos procesos clave para la din\u00e1mica de la estructura forestal: la regeneraci\u00f3n sexual y la respuesta de los bosques maduros al gradiente hidrol\u00f3gico local. La dispersi\u00f3n, germinaci\u00f3n de semillas y estudios en invernadero sugirieron que las estrategias de regeneraci\u00f3n sexual de una de las especies aparentemente m\u00e1s negativamente afectadas por el nuevo r\u00e9gimen hidrogeomorfol\u00f3gico, p. Alba, eran equivalentes a aquellas de otras especies pioneras en el mundo, subrayando el potencial para la restauraci\u00f3n forestal basada en la renaturalizaci\u00f3n del r\u00e9gimen hidrogeomorfol\u00f3gico. La relaci\u00f3n entre las tasas de mortalidad de p. Alba, p. Nigra, s. Alba y tamarix spp. Y la hidrolog\u00eda local fue examinada en detalle despu\u00e9s de monitorizar el nivel fre\u00e1tico en 2007, 2008 y 2009. Todas las especies exhibieron relaciones significativas, lo que fue interpretado como una evidencia de su naturaleza freat\u00f3fita (i.E., Dependencia del acu\u00edfero). Esta informaci\u00f3n se utiliz\u00f3 para proponer unos umbrales hidrol\u00f3gicos para la conservaci\u00f3n de sus poblaciones maduras. Sorprendentemente, el cambio en composici\u00f3n de especies de salicaceae a tamaricaceae con condiciones m\u00e1s secas, observado en otras regiones semi-\u00e1ridas del mundo, no se detect\u00f3 en el ebro. \u00fanicamente s. Alba perd\u00eda importancia de forma significativa con hidroper\u00edodos m\u00e1s secos, respecto a las otras especies. el contenido foliar de nutrientes en \u00e1rboles riparios ha sido examinado como indicador de la limitaci\u00f3n de nutrientes en llanuras de inundaci\u00f3n arboladas para discutir las consecuencias de posibles diferencias en el uso de nutrientes sobre la competici\u00f3n entre dos g\u00e9neros de \u00e1rboles dominantes en las regiones semi-\u00e1ridas del mundo: populus y tamarix. As\u00ed, la variabilidad estacional y espacial en nitr\u00f3geno (n) y f\u00f3sforo (p) foliar se analiz\u00f3 en 720 hojas (2 g\u00e9neros x 3 estaciones x 12 unidades geomorfol\u00f3gicas x 10 r\u00e9plicas). Los resultados mostraron que tamarix es m\u00e1s variable que populus en su contenido foliar de n y p, lo que parece reforzar la hip\u00f3tesis de que tamarix est\u00e1 mejor adaptada a escenarios con baja perturbaci\u00f3n y alto estr\u00e9s (estabilizaci\u00f3n de la llanura de inundaci\u00f3n y estr\u00e9s h\u00eddrico y de nutrientes), respecto a populus, m\u00e1s eficaz en ambientes de alta perturbaci\u00f3n y bajo estr\u00e9s (perturbaci\u00f3n de inundaciones mayor pero disponibilidad de agua y nutrientes), lo que dar\u00eda una nueva explicaci\u00f3n al \u00e9xito de tamarix en r\u00edos regulados. No obstante, estas diferencias se oscurecieron por una componente espacial m\u00e1s fuerte que afect\u00f3 a ambos g\u00e9neros, como mostraron modelos lineales con efectos mixtos (lme). En general, a duraciones de inundaci\u00f3n m\u00e1s cortas, la p\u00e9rdida de n y p de los \u00e1rboles durante la ca\u00edda de hojas era menor y la relaci\u00f3n n:p aumentaba. la respuesta de la producci\u00f3n de hojarasca a gradientes hidrol\u00f3gicos tambi\u00e9n se examin\u00f3, como una funci\u00f3n clave de los bosques para el ecosistema ripario. En 2007, la ca\u00edda de hojarasca fue seguida mensualmente en 12 parcelas que cubr\u00edan una variedad de unidades forestales con diferente estructura, suelo e hidroper\u00edodo. Modelos lme y partici\u00f3n jer\u00e1rquica se emplearon para evaluar la variabilidad espacial en la producci\u00f3n de hojarasca y para explorar la importancia relativa de 17 par\u00e1metros (representativos de la estructura forestal, suelo, hidroper\u00edodo y qu\u00edmica de la hojarasca) como potenciales predictores de la producci\u00f3n de hojarasca. Los resultados sugirieron que, aunque la producci\u00f3n en los bosques riparios del ebro (media = 563 g\u00c2\u00bfm-2\u00c2\u00bfa\u00f1o-1) es medio-alta comparada con medias globales y regionales, la limitaci\u00f3n de p podr\u00eda estar reduci\u00e9ndola en los rodales m\u00e1s externos debido a un aporte insuficiente de sedimentos con nutrientes adheridos al escasear las riadas superficiales. La estructura forestal fue responsable del 30% de la variabilidad explicada, mientras que el r\u00e9gimen de inundaciones y la fertilidad del suelo, directa o indirectamente por medio de los par\u00e1metros de la qu\u00edmica de la hojarasca, explicaron el restante 70%. bas\u00e1ndose en todos estos resultados, que destacaron la dependencia de los bosques riparios del ebro medio a las perturbaciones, se recomienda la recuperaci\u00f3n de cierta din\u00e1mica hidrogeomorfol\u00f3gica a diferentes escalas (cuenca, tramo y parcela) para garantizar la auto-sostenibilidad de su estructura, funcionamiento y servicios ecol\u00f3gicos gratuitos que proporcionan. Estas recomendaciones podr\u00edan ayudar a tomar decisiones de gesti\u00f3n exitosas en otras cuencas semi-\u00e1ridas y mediterr\u00e1neas con constricciones hidrogeomorfol\u00f3gicas similares a las del ebro medio. palabras clave: contenido foliar en n y p, estructura forestal riparia, gesti\u00f3n, modelos lineales con efectos mixtos (lme), populus alba, populus nigra, producci\u00f3n de hojarasca, regeneraci\u00f3n sexual, r\u00e9gimen hidrogeomorfol\u00f3gico, regulaci\u00f3n fluvial, r\u00edo mediterr\u00e1neo, r\u00edo semi-\u00e1rido, salix alba, senescencia, tamarix spp., Tramo medio del r\u00edo ebro, uso de nutrientes por \u00e1rboles riparios<\/p>\n<p>&nbsp;<\/p>\n<h3>Datos acad\u00e9micos de la tesis doctoral \u00ab<strong>Contribution to the ecology of the middle ebro riparian woodlands: implications for management (ingles). contribuci\u00f3n a la ecolog\u00eda de los bosques riparios del ebro medio: implicaciones para la gesti\u00f3n( espa\u00f1ol)<\/strong>\u00ab<\/h3>\n<ul>\n<li><strong>T\u00edtulo de la tesis:<\/strong>\u00a0 Contribution to the ecology of the middle ebro riparian woodlands: implications for management (ingles). contribuci\u00f3n a la ecolog\u00eda de los bosques riparios del ebro medio: implicaciones para la gesti\u00f3n( espa\u00f1ol) <\/li>\n<li><strong>Autor:<\/strong>\u00a0 Eduardo Gonz\u00e1lez Sargas <\/li>\n<li><strong>Universidad:<\/strong>\u00a0 Alcal\u00e1<\/li>\n<li><strong>Fecha de lectura de la tesis:<\/strong>\u00a0 06\/07\/2010<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<h3>Direcci\u00f3n y tribunal<\/h3>\n<ul>\n<li><strong>Director de la tesis<\/strong>\n<ul>\n<li>Francisco A. Com\u00edn Sebastian<\/li>\n<\/ul>\n<\/li>\n<li><strong>Tribunal<\/strong>\n<ul>\n<li>Presidente del tribunal: eric Tabacchi <\/li>\n<li>Jos\u00e9 Mar\u00eda Rey benayas (vocal)<\/li>\n<li>dov Corenblit (vocal)<\/li>\n<li>francine Hughes (vocal)<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Tesis doctoral de Eduardo Gonz\u00e1lez Sargas English version the riparian woodland ecology of one of the largest regulated mediterranean rivers, [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""}},"footnotes":""},"categories":[16509,17426,620,3499],"tags":[207966,207964,207965,207967,18850,55268],"class_list":["post-102535","post","type-post","status-publish","format-standard","hentry","category-aguas-superficiales","category-alcala","category-ecologia-vegetal","category-hidrogeologia","tag-dov-corenblit","tag-eduardo-gonzalez-sargas","tag-eric-tabacchi","tag-francine-hughes","tag-francisco-a-comin-sebastian","tag-jose-maria-rey-benayas"],"_links":{"self":[{"href":"https:\/\/www.deberes.net\/tesis\/wp-json\/wp\/v2\/posts\/102535","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.deberes.net\/tesis\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.deberes.net\/tesis\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.deberes.net\/tesis\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.deberes.net\/tesis\/wp-json\/wp\/v2\/comments?post=102535"}],"version-history":[{"count":0,"href":"https:\/\/www.deberes.net\/tesis\/wp-json\/wp\/v2\/posts\/102535\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.deberes.net\/tesis\/wp-json\/wp\/v2\/media?parent=102535"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.deberes.net\/tesis\/wp-json\/wp\/v2\/categories?post=102535"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.deberes.net\/tesis\/wp-json\/wp\/v2\/tags?post=102535"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}