{"id":1131,"date":"2016-09-15T13:48:43","date_gmt":"2016-09-15T13:48:43","guid":{"rendered":"https:\/\/optmix.efno.fr\/?p=1131"},"modified":"2016-09-19T13:33:04","modified_gmt":"2016-09-19T13:33:04","slug":"experimentations-en-cours-sur-les-effets-de-la-secheresse","status":"publish","type":"post","link":"https:\/\/optmix.efno.fr\/?p=1131","title":{"rendered":"Exp\u00e9rimentations en cours sur les effets de la s\u00e9cheresse"},"content":{"rendered":"<p>Apr\u00e8s\u00a0un printemps 2016 tr\u00e8s pluvieux une s\u00e9cheresse importante s&rsquo;est install\u00e9e de juillet \u00e0 ao\u00fbt avec\u00a0des pr\u00e9cipitations tr\u00e8s faibles (20 mm sur les deux mois) et des temp\u00e9ratures tr\u00e8s \u00e9lev\u00e9es (plusieurs jours sup\u00e9rieurs \u00e0 35\u00b0C). Ces conditions climatiques ajout\u00e9es aux conditions de sols tr\u00e8s contraignantes de la for\u00eat d&rsquo;Orl\u00e9ans\u00a0ont entra\u00een\u00e9 un stress important pour les arbres. Afin de mieux comprendre les effets de la\u00a0s\u00e9cheresse sur le fonctionnement hydrique des arbres, des exp\u00e9rimentations ont \u00e9t\u00e9 r\u00e9alis\u00e9es pendant l&rsquo;\u00e9t\u00e9 dans le cadre de la th\u00e8se de Jordan Bello (doctorant Irstea). Deux m\u00e9thodes\u00a0ont \u00e9t\u00e9 mises en oeuvre : la premi\u00e8re m\u00e9thode\u00a0est bas\u00e9e sur la mesure du\u00a0potentiel hydrique foliaire de base et l&rsquo;autre sur la mesure du rapport isotopique de l&rsquo;oxyg\u00e8ne (O18 et O16) contenu dans l&rsquo;eau du sol et dans l&rsquo;eau des v\u00e9g\u00e9taux. Ces m\u00e9thodes permettront\u00a0d&rsquo;estimer le stress subit par les arbres et\u00a0d&rsquo;estimer la profondeur d&rsquo;acquisition de l&rsquo;eau par les arbres. L&rsquo;\u00e9chantillonnage a \u00e9t\u00e9 r\u00e9alis\u00e9 de fa\u00e7on \u00e0 savoir\u00a0si le stress et la profondeur d&rsquo;acquisition de l&rsquo;eau en cas de s\u00e9cheresse d\u00e9pendent de la composition du peuplement (pur ou m\u00e9lang\u00e9).<\/p>\n<p>&nbsp;<\/p>\n<p><a href=\"https:\/\/optmix.efno.fr\/wp-content\/uploads\/2016\/09\/Isotope_sol_CC_small.jpg\"><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-medium wp-image-1148\" src=\"https:\/\/optmix.efno.fr\/wp-content\/uploads\/2016\/09\/Isotope_sol_CC_small-300x225.jpg\" alt=\"isotope_sol_cc_small\" width=\"300\" height=\"225\" srcset=\"https:\/\/optmix.efno.fr\/wp-content\/uploads\/2016\/09\/Isotope_sol_CC_small-300x225.jpg 300w, https:\/\/optmix.efno.fr\/wp-content\/uploads\/2016\/09\/Isotope_sol_CC_small-768x576.jpg 768w, https:\/\/optmix.efno.fr\/wp-content\/uploads\/2016\/09\/Isotope_sol_CC_small.jpg 900w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/a><a href=\"https:\/\/optmix.efno.fr\/wp-content\/uploads\/2016\/09\/Potentiel_CC_small.jpg\"><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-medium wp-image-1147\" src=\"https:\/\/optmix.efno.fr\/wp-content\/uploads\/2016\/09\/Potentiel_CC_small-300x225.jpg\" alt=\"potentiel_cc_small\" width=\"300\" height=\"225\" srcset=\"https:\/\/optmix.efno.fr\/wp-content\/uploads\/2016\/09\/Potentiel_CC_small-300x225.jpg 300w, https:\/\/optmix.efno.fr\/wp-content\/uploads\/2016\/09\/Potentiel_CC_small-768x576.jpg 768w, https:\/\/optmix.efno.fr\/wp-content\/uploads\/2016\/09\/Potentiel_CC_small.jpg 900w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Apr\u00e8s\u00a0un printemps 2016 tr\u00e8s pluvieux une s\u00e9cheresse importante s&rsquo;est install\u00e9e de juillet \u00e0 ao\u00fbt avec\u00a0des pr\u00e9cipitations tr\u00e8s faibles (20 mm sur les deux mois) et des temp\u00e9ratures tr\u00e8s \u00e9lev\u00e9es (plusieurs jours sup\u00e9rieurs \u00e0 35\u00b0C). Ces conditions climatiques ajout\u00e9es aux conditions de sols tr\u00e8s contraignantes de la for\u00eat d&rsquo;Orl\u00e9ans\u00a0ont entra\u00een\u00e9 un stress important pour les arbres. &hellip; <\/p>\n<p><a class=\"more-link btn\" href=\"https:\/\/optmix.efno.fr\/?p=1131\">Lire la suite<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_mi_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"footnotes":""},"categories":[1],"tags":[],"_links":{"self":[{"href":"https:\/\/optmix.efno.fr\/index.php?rest_route=\/wp\/v2\/posts\/1131"}],"collection":[{"href":"https:\/\/optmix.efno.fr\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/optmix.efno.fr\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/optmix.efno.fr\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/optmix.efno.fr\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1131"}],"version-history":[{"count":8,"href":"https:\/\/optmix.efno.fr\/index.php?rest_route=\/wp\/v2\/posts\/1131\/revisions"}],"predecessor-version":[{"id":1154,"href":"https:\/\/optmix.efno.fr\/index.php?rest_route=\/wp\/v2\/posts\/1131\/revisions\/1154"}],"wp:attachment":[{"href":"https:\/\/optmix.efno.fr\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1131"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/optmix.efno.fr\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1131"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/optmix.efno.fr\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1131"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}