PAR\u00cd\u017d – Kedysi majest\u00e1tny dub je dnes prakticky m\u0155tvy. Po opakovan\u00fdch vln\u00e1ch hor\u00fa\u010dav zastavil svoje \u017eivotn\u00e9 funkcie, aby \u0161etril vodu, a v jednom z franc\u00fazskych lesov pomaly hynie. Ide o jeden z mnoh\u00fdch stromov v eur\u00f3pskych lesoch, ktor\u00e9 volia drastick\u00e9 a \u010dasto smrte\u013en\u00e9 met\u00f3dy pre\u017eitia tv\u00e1rou v tv\u00e1r zhor\u0161uj\u00facim sa vln\u00e1m hor\u00fa\u010dav a such\u00e1m s\u00favisiacim so zmenou kl\u00edmy, nap\u00edsala agent\u00fara AFP.<\/p>\n
Zatia\u013e \u010do Franc\u00fazsko za\u017e\u00edva rekordn\u00fa vlnu hor\u00fa\u010dav na za\u010diatku letnej sez\u00f3ny, vedci varuj\u00fa, \u017ee mnoh\u00e9 eur\u00f3pske lesy u\u017e nes\u00fa stopy nieko\u013eko rokov rast\u00facich tepl\u00f4t a intenz\u00edvneho sucha. Rovnako ako \u013eudia, ktor\u00ed sa ochladzuj\u00fa poten\u00edm, stromy reguluj\u00fa svoju teplotu transpir\u00e1ciou. To znamen\u00e1, \u017ee \u010derpaj\u00fa vodu z p\u00f4dy a uvo\u013e\u0148uj\u00fa ju vo forme pary cez drobn\u00e9 p\u00f3ry v listoch. S rast\u00facimi teplotami sa strata vody z listov a p\u00f4dy zr\u00fdch\u013euje, \u010do stromy n\u00fati k z\u00fafal\u00fdm opatreniam, aby si udr\u017eali vlhkos\u0165.<\/p>\n
Manuel Nicolas z franc\u00fazskeho N\u00e1rodn\u00e9ho lesn\u00edckeho \u00faradu tento jav sk\u00fama v lesoch po celej krajine u\u017e desa\u0165ro\u010dia. \u201eV\u0161etky stromy trpia, ale ich reakcie na teplotn\u00fd stres sa l\u00ed\u0161ia v z\u00e1vislosti od druhu a lokality,\u201c uviedol Nicolas, ktor\u00fd vedie n\u00e1rodn\u00fd program monitorovania lesn\u00fdch ekosyst\u00e9mov. Niektor\u00e9 stromy obmedzuj\u00fa stratu vody t\u00fdm, \u017ee r\u00fdchlo uzatv\u00e1raj\u00fa svoje prieduchy \u2013 mikroskopick\u00e9 p\u00f3ry na listoch alebo ihliciach, ktor\u00e9 reguluj\u00fa v\u00fdmenu plynov a uvo\u013e\u0148ovanie vodnej pary. Uzavretie prieduchov \u0161etr\u00ed vodu, no spoma\u013euje a\u017e zastavuje fotosynt\u00e9zu, teda proces, ktor\u00fd premie\u0148a slne\u010dn\u00e9 svetlo, oxid uhli\u010dit\u00fd a vodu na cukry potrebn\u00e9 pre rast a pre\u017eitie rastl\u00edn. Po \u010dase tak m\u00f4\u017ee strom v podstate vyhladova\u0165.<\/p>\n
Stromy s\u00fa vystavovan\u00e9 extr\u00e9mnym podmienkam<\/p>\n
\u010eal\u0161ou strat\u00e9giou, ktor\u00fa uprednost\u0148uj\u00fa najm\u00e4 stromy s hlbok\u00fdm kore\u0148ov\u00fdm syst\u00e9mom, je \u010derpanie vody z p\u00f4dy a udr\u017eiavanie prieduchov otvoren\u00fdch \u010do najdlh\u0161ie, poznamenal Nicolas. \u201eRizikom je v\u0161ak tentoraz smr\u0165 v d\u00f4sledku nedostatku vody,\u201c dodal vo Fontainebleau, rozsiahlom lese pribli\u017ene 60 kilometrov ju\u017ene od Par\u00ed\u017ea. Pod\u013ea Nicolasa je strom st\u013apcom vody, ktor\u00fd dok\u00e1\u017ee absorbova\u0165 a\u017e 200 litrov tekutiny denne a pren\u00e1\u0161a vlhkos\u0165 zo zeme do koruny. Tento syst\u00e9m v\u0161ak m\u00f4\u017ee by\u0165 pre\u0165a\u017een\u00fd hor\u00fa\u010davou alebo suchom a \u00faplne skolabova\u0165. \u201eDo ciev sa dost\u00e1vaj\u00fa vzduchov\u00e9 bubliny a br\u00e1nia cirkul\u00e1cii miazgy a\u017e ku koncom kon\u00e1rov. Tomu sa hovor\u00ed plynov\u00e1 emb\u00f3lia,\u201c povedal. \u201eA ke\u010f emb\u00f3lia postihne pr\u00edli\u0161 ve\u013ea ciev, cel\u00fd strom uhynie na dehydrat\u00e1ciu,\u201c dodal.<\/p>\n
Vedci tvrdia, \u017ee s rast\u00facou \u010dastos\u0165ou v\u013an hor\u00fa\u010dav a sucha s\u00fa stromy \u010doraz \u010dastej\u0161ie vystavovan\u00e9 t\u00fdmto extr\u00e9mnym podmienkam. Vo Franc\u00fazsku, kde sa nach\u00e1dzaj\u00fa jedny z najrozmanitej\u0161\u00edch lesov v Eur\u00f3pe, vl\u00e1dne \u0161tatistiky ukazuj\u00fa, \u017ee \u00fahyn stromov sa za posledn\u00fdch desa\u0165 rokov zdvojn\u00e1sobil. Progn\u00f3zy nazna\u010duj\u00fa, \u017ee do roku 2050 by mohlo ubudn\u00fa\u0165 pribli\u017ene 30 percent druhov stromov. Odborn\u00edci tvrdia, \u017ee lesy s\u00fa n\u00faten\u00e9 r\u00fdchlo sa prisp\u00f4sobova\u0165 klimatick\u00fdm zmen\u00e1m, ktor\u00e9 sa za norm\u00e1lnych okolnost\u00ed odohr\u00e1vaj\u00fa v priebehu tis\u00edcro\u010d\u00ed. Od predindustri\u00e1lnej \u00e9ry sa plan\u00e9ta Zem oteplila pribli\u017ene o 1,4 stup\u0148a Celzia a pod\u013ea vedcov je s\u00fa\u010dasn\u00e1 kl\u00edma pravdepodobne najteplej\u0161ia, ak\u00fa Zem za\u017eila za posledn\u00fdch 125-tis\u00edc rokov.<\/p>\n
Dopad na stromy je vidite\u013en\u00fd vo\u013en\u00fdm oko<\/p>\n
Dopad na stromy vo Fontainebleau je vidite\u013en\u00fd vo\u013en\u00fdm okom. Niektor\u00e9 obry tam zhodili svoje kon\u00e1re a listy v m\u00e1rnej snahe pre\u017ei\u0165. Medzi nimi je dub \u010d\u00edslo 37, ktor\u00fd st\u00e1le stoj\u00ed, no bez kon\u00e1rov a zbeda\u010den\u00fd. Nicolas a jeho t\u00edm ozna\u010duj\u00fa a pozoruj\u00fa stromy vo Fontainebleau u\u017e 34 rokov a vedia, \u017ee sa bl\u00ed\u017ei jeho koniec. In\u00e9 stromy v okol\u00ed v\u0161ak zost\u00e1vaj\u00fa vysok\u00e9 a zdrav\u00e9 z d\u00f4vodov, ktor\u00e9 vedci st\u00e1le sk\u00famaj\u00fa.<\/p>\n
Intenz\u00edvna vlna hor\u00fa\u010dav v roku 2018 zni\u010dila vo Fontainebleau skupinu borov\u00edc, ale in\u00e9 ihli\u010dnany v lese prosperovali z d\u00f4vodov, ktor\u00fdm vedci st\u00e1le dobre nerozumej\u00fa.\u00a0\u201eNiektor\u00e9 druhy stromov, napr\u00edklad tie stredomorsk\u00e9, m\u00f4\u017eu by\u0165 vo\u010di hor\u00fa\u010dave odolnej\u0161ie,\u201c povedal Nicolas. \u201eS\u00fa lep\u0161ie prisp\u00f4soben\u00e9 such\u00fdm podmienkam, preto\u017ee obmedzuj\u00fa stratu vody transpir\u00e1ciou v\u010faka mal\u00fdm, ko\u017eovit\u00fdm listom pokryt\u00fdm ch\u013apkami alebo nepriepustnou vrstvou, ako je to napr\u00edklad pri dube cezm\u00ednovom,\u201c povedal. Pod\u013ea Nicolasa je pre ochranu lesov pred nadch\u00e1dzaj\u00facimi hor\u00fa\u010davami k\u013e\u00fa\u010dov\u00e9 pochopi\u0165, ktor\u00e9 druhy bud\u00fa vhodn\u00e9 o 100 rokov. \u201eProti vln\u00e1m hor\u00fa\u010dav toho ve\u013ea urobi\u0165 nem\u00f4\u017eeme. M\u00f4\u017eeme sa v\u0161ak pok\u00fasi\u0165 pom\u00f4c\u0165 lesom prisp\u00f4sobi\u0165 sa,\u201c dodal.<\/p>\n","protected":false},"excerpt":{"rendered":"PAR\u00cd\u017d – Kedysi majest\u00e1tny dub je dnes prakticky m\u0155tvy. Po opakovan\u00fdch vln\u00e1ch hor\u00fa\u010dav zastavil svoje \u017eivotn\u00e9 funkcie, aby…\n","protected":false},"author":2,"featured_media":84316,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_share_on_mastodon":"0"},"categories":[8],"tags":[30639,317,33,43,40,42,36,7730,50,49,48],"class_list":["post-84315","post","type-post","status-publish","format-standard","has-post-thumbnail","category-svet","tag-fontainebleau","tag-francuzsko","tag-news","tag-sk","tag-slovak","tag-slovencina","tag-spravy","tag-stromy","tag-svet","tag-world","tag-world-news"],"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@sk\/116664348595105869","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/sk\/wp-json\/wp\/v2\/posts\/84315","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/sk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/sk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/sk\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/sk\/wp-json\/wp\/v2\/comments?post=84315"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/sk\/wp-json\/wp\/v2\/posts\/84315\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/sk\/wp-json\/wp\/v2\/media\/84316"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/sk\/wp-json\/wp\/v2\/media?parent=84315"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/sk\/wp-json\/wp\/v2\/categories?post=84315"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/sk\/wp-json\/wp\/v2\/tags?post=84315"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}