![\"\"](\"http:\/\/helix.mendelu.cz\/oryx\/les_jako_ekosystem\/wp-content\/uploads\/2018\/05\/slunecni_zareni.jpg\")
<\/p>\n
- \n
- – z\u00e1kladn\u00ed jednotkou z\u00e1\u0159en\u00ed \u2013 foton, kter\u00fd se m\u016f\u017ee jevit bu\u010f jako \u010d\u00e1stice nebo jako vln\u011bn\u00ed<\/li>\n
- – UV (7%), FAR (47%), IR (46%)<\/li>\n
- – na horn\u00ed hranici atmosf\u00e9ry dopad\u00e1 mno\u017estv\u00ed = sol\u00e1rn\u00ed konstanta<\/li>\n
- – So = 1373 \u00b1 20 W.m-2<\/li>\n
- – asi 1\/3 se odr\u00e1\u017e\u00ed zp\u011bt do kosmick\u00e9ho prostoru, zb\u00fdvaj\u00edc\u00ed \u010d\u00e1st pronik\u00e1 atmosf\u00e9rou, je j\u00ed zeslabov\u00e1na a m\u011bn\u00ed se spektr\u00e1ln\u00ed slo\u017een\u00ed.<\/li>\n
- – obvykle m\u011b\u0159en\u00e9 max. v \u010cR: 1000 W.m-2 ; max.denn\u00ed suma 30 MJ. m-2<\/li>\n<\/ul>\n
![\"\"](\"http:\/\/helix.mendelu.cz\/oryx\/les_jako_ekosystem\/wp-content\/uploads\/2018\/05\/8_forem_vyzarovane_energie.jpg\")
<\/p>\n\u00da\u010dinky z\u00e1\u0159en\u00ed na rostliny<\/h2>\n
![\"\"](\"http:\/\/helix.mendelu.cz\/oryx\/les_jako_ekosystem\/wp-content\/uploads\/2018\/05\/ucinky_zareni_na_rostliny.jpg\")
<\/p>\nModifikace z\u00e1\u0159en\u00ed rostlinou<\/h2>\n
P\u0159i pr\u016fchodu sv\u011btla listov\u00edm doch\u00e1z\u00ed k t\u011bmto z\u00e1kladn\u00edm jev\u016fm:<\/p>\n
Reflexe (odraz)<\/h3>\n
- \n
- \u2013 zelen\u00e9 listy odr\u00e1\u017eej\u00ed p\u0159ibli\u017en\u011b 10\u201320% slune\u010dn\u00edch paprsk\u016f (v z\u00e1vislosti na postaven\u00ed list\u016f a povaze povrchu list\u016f)<\/li>\n<\/ul>\n
absorpce<\/h3>\n
- \n
- \u2013 velk\u00e9 mno\u017estv\u00ed z\u00e1\u0159en\u00ed je absorbov\u00e1no, ale z t\u00e9to energie je pr\u016fm\u011brn\u011b pouh\u00e9 1% vyu\u017eito pro fotosynt\u00e9zu. V\u0161echna absorbovan\u00e1 energie s v\u00fdjimkou mal\u00e9 \u010d\u00e1sti v\u00e1zan\u00e9 fotosynt\u00e9zou je p\u0159em\u011bn\u011bna v teplo.<\/li>\n<\/ul>\n
![\"\"](\"http:\/\/helix.mendelu.cz\/oryx\/les_jako_ekosystem\/wp-content\/uploads\/2018\/05\/zareni_spektralni_absorpce.jpg\")
<\/p>\nTransmise<\/h2>\n
\u2013 z\u00e1\u0159en\u00ed, kter\u00e9 proch\u00e1z\u00ed listem (jeho mno\u017estv\u00ed a kvalita je z\u00e1visl\u00e1 p\u0159edev\u0161\u00edm na tlou\u0161\u0165ce listu). Tato kvalitativn\u00ed zm\u011bna je velmi d\u016fle\u017eit\u00e1 pro mnoho druh\u016f rostlin, kter\u00e9 d\u00edky pigment\u016fm dok\u00e1\u017e\u00ed reagovat na zm\u011bnu slo\u017een\u00ed sv\u011btla, konkr\u00e9tn\u011b na zm\u011bnu pom\u011bru \u010derven\u00e9ho ku infra\u010derven\u00e9mu sv\u011btlu (umo\u017e\u0148uje rostlin\u00e1m reagovat na p\u0159\u00edtomnost p\u0159\u00edpadn\u00fdch konkurent\u016f, informuje je to o vytvo\u0159en\u00ed voln\u00e9ho prostoru v porostu a v neposledn\u00ed \u0159ad\u011b je to velmi d\u016fle\u017eit\u00fd inhibi\u010dn\u00ed faktor vyvol\u00e1vaj\u00edc\u00ed stav dormance u n\u011bkter\u00fdch druh\u016f rostlin).<\/p>\n
Modifikace z\u00e1\u0159en\u00ed porostem<\/h2>\n
P\u0159i dopadu slune\u010dn\u00edho z\u00e1\u0159en\u00ed na porost doch\u00e1z\u00ed k:<\/p>\n
- \n
- – spektr\u00e1ln\u011b selektivn\u00edmu odrazu<\/li>\n
- – pr\u016fniku (transmisi) do spodn\u00edch \u010d\u00e1st\u00ed porostu<\/li>\n
- – spektr\u00e1ln\u011b z\u00e1visl\u00e9mu \u010d\u00e1ste\u010dn\u00e9mu pohlcov\u00e1n\u00ed (absorpci)<\/li>\n<\/ul>\n
Spektr\u00e1ln\u00ed slo\u017een\u00ed slune\u010dn\u00edho z\u00e1\u0159en\u00ed uvnit\u0159 porostu je tak odli\u0161n\u00e9 od z\u00e1\u0159en\u00ed na porost dopadaj\u00edc\u00edho.<\/p>\n
![\"\"](\"http:\/\/helix.mendelu.cz\/oryx\/les_jako_ekosystem\/wp-content\/uploads\/2018\/05\/zareni_na_ruzne_rostliny.jpg\")
<\/p>\nRelativn\u00ed oz\u00e1\u0159enost<\/h2>\n
– relativn\u00ed sv\u011bteln\u00fd po\u017eitek = intenzita oz\u00e1\u0159en\u00ed uvnit\u0159 rostlinn\u00e9ho porostu v % pln\u00e9ho oz\u00e1\u0159en\u00ed na voln\u00e9 plo\u0161e
\n– opadav\u00e9 lesy, \u0159\u00eddk\u00e9 porosty jehli\u010dnan\u016f m\u00edrn\u00e9ho p\u00e1sma ve vegeta\u010dn\u00edm obdob\u00ed 10-20%, v zim\u011b 50-70%
\n– v hust\u00fdch jehli\u010dnat\u00fdch porostech \u2013 n\u011bkolik m\u00e1lo %<\/p>\n\u00dabytek z\u00e1\u0159en\u00ed v porostu z\u00e1vis\u00ed hlavn\u011b na:
\n– hustot\u011b listov\u00ed (LAI)
\n– na uspo\u0159\u00e1d\u00e1n\u00ed list\u016f<\/p>\nSez\u00f3nn\u00ed zm\u011bny v pr\u016fniku slune\u010dn\u00edho z\u00e1\u0159en\u00ed lesn\u00edmi porosty podmi\u0148uj\u00ed rytmus v\u00fdvoje rostlin bylinn\u00e9ho patra. Nap\u0159. v listnat\u00e9m opadav\u00e9m lese se vytv\u00e1\u0159\u00ed jarn\u00ed jarn\u00ed_aspekta pozd\u011bji letn\u00ed aspekt letn\u00ed_aspekt. Pot\u0159eba i tolerance slune\u010dn\u00edho z\u00e1\u0159en\u00ed u rostlin i jejich jednotliv\u00fdch org\u00e1n\u016f je r\u016fzn\u00e1.
\n– minim\u00e1ln\u00ed oz\u00e1\u0159en\u00ed je ur\u010deno sv\u011bteln\u00fdm kompenza\u010dn\u00edm bodem fotosynt\u00e9zy sv\u011bteln\u00fd_kompenza\u010dn\u00ed_bod_fotosynt\u00e9zy
\n– minim\u00e1ln\u00ed pr\u016fm\u011brn\u00e1 hustota oz\u00e1\u0159en\u00ed, p\u0159i n\u00ed\u017e rostliny mohou je\u0161t\u011b r\u016fst, mus\u00ed le\u017eet nad t\u00edmto kompenza\u010dn\u00edm bodem a celkov\u00e1 denn\u00ed \u010dist\u00e1 fotosynt\u00e9za mus\u00ed kompenzovat ve\u0161ker\u00e9 i no\u010dn\u00ed ztr\u00e1ty d\u00fdch\u00e1n\u00edm.<\/p>\nK n\u011bkter\u00fdm projev\u016fm rostlin nesta\u010d\u00ed jen ur\u010dit\u00e1 intenzita a kvalita z\u00e1\u0159en\u00ed nebo jeho suma, ale t\u00e9\u017e ur\u010dit\u00e9 st\u0159\u00edd\u00e1n\u00ed sv\u011btla a tmy. Jde o fotoperiodismus, kter\u00fdm se rozum\u00ed d\u00e9lka denn\u00edho osv\u011btlen\u00ed, tzv. fotoperiody, rozhoduj\u00edc\u00ed o p\u0159echodu rostliny do reproduk\u010dn\u00ed f\u00e1ze.<\/p>\n
Slune\u010dn\u00ed z\u00e1\u0159en\u00ed p\u0159i sv\u00e9m pr\u016fchodu porostem mus\u00ed proj\u00edt postupn\u011b v\u0161emi patry listov\u00ed
\n– jeho intenzita kles\u00e1 t\u00e9m\u011b\u0159 exponenci\u00e1ln\u011b podle vzr\u016fstaj\u00edc\u00edho mno\u017estv\u00ed pokryvu (ve shod\u011b s Lambert-Beerov\u00fdm extink\u010dn\u00edm z\u00e1konem)
\n– p\u0159edpoklad: homogennost listov\u00fdch pater \u2013 pokles hustoty oz\u00e1\u0159en\u00ed: I = Io * e \u2013k * LAI
\n– extink\u010dn\u00ed koeficient ud\u00e1v\u00e1 stupe\u0148 oslaben\u00ed z\u00e1\u0159en\u00ed uvnit\u0159 porostu p\u0159i dan\u00e9m LAI<\/p>\nAbsorpce slune\u010dn\u00edho z\u00e1\u0159en\u00ed v porostech<\/h2>\n
Zachycen\u00e9 slune\u010dn\u00ed z\u00e1\u0159en\u00ed = rozd\u00edl mezi slune\u010dn\u00edm dopaden\u00fdm na porost a slune\u010dn\u00edm z\u00e1\u0159en\u00edm uvnit\u0159 nebo pod porostem
\nCharakter absorpce je d\u00e1n:<\/p>\n- \n
- – strukturou porostu (spon a vertik\u00e1ln\u00ed stratifikaci list\u016f v porostu i orientaci a inklinaci list\u016f)<\/li>\n
- – absorp\u010dn\u00edmi a reflexn\u00edmi vlastnosti list\u016f<\/li>\n<\/ul>\n
![\"\"](\"http:\/\/helix.mendelu.cz\/oryx\/les_jako_ekosystem\/wp-content\/uploads\/2018\/05\/absorpce.jpg\")
<\/p>\nSlune\u010dn\u00ed z\u00e1\u0159en\u00ed jako produk\u010dn\u00ed faktor<\/h3>\n
- \n
- – zachycen\u00e1 a absorbovan\u00e1 FAR – k odvozen\u00ed \u010dist\u00e9 prim\u00e1rn\u00ed produkce<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"
Slune\u010dn\u00ed z\u00e1\u0159en\u00ed Slunce \u2013 zdroj energie – p\u0159i praktick\u00fdch m\u011b\u0159en\u00edch se v popisu experiment\u00e1ln\u00edch podm\u00ednek pou\u017e\u00edvaj\u00ed jednotky: – W.m-2 intenzita z\u00e1\u0159en\u00ed (W \u2013 v\u00fdkon, z\u00e1\u0159iv\u00fd tok) – J.m-2.s-1 mno\u017estv\u00ed z\u00e1\u0159en\u00ed (J \u2013 pr\u00e1ce, energie) – z\u00e1kladn\u00ed jednotkou z\u00e1\u0159en\u00ed \u2013 foton, kter\u00fd se m\u016f\u017ee jevit bu\u010f jako \u010d\u00e1stice nebo jako vln\u011bn\u00ed – UV (7%), FAR (47%), […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":39,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":[],"_links":{"self":[{"href":"https:\/\/rumex.mendelu.cz\/oryx\/les_jako_ekosystem\/index.php\/wp-json\/wp\/v2\/pages\/43"}],"collection":[{"href":"https:\/\/rumex.mendelu.cz\/oryx\/les_jako_ekosystem\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/rumex.mendelu.cz\/oryx\/les_jako_ekosystem\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/rumex.mendelu.cz\/oryx\/les_jako_ekosystem\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/rumex.mendelu.cz\/oryx\/les_jako_ekosystem\/index.php\/wp-json\/wp\/v2\/comments?post=43"}],"version-history":[{"count":4,"href":"https:\/\/rumex.mendelu.cz\/oryx\/les_jako_ekosystem\/index.php\/wp-json\/wp\/v2\/pages\/43\/revisions"}],"predecessor-version":[{"id":123,"href":"https:\/\/rumex.mendelu.cz\/oryx\/les_jako_ekosystem\/index.php\/wp-json\/wp\/v2\/pages\/43\/revisions\/123"}],"up":[{"embeddable":true,"href":"https:\/\/rumex.mendelu.cz\/oryx\/les_jako_ekosystem\/index.php\/wp-json\/wp\/v2\/pages\/39"}],"wp:attachment":[{"href":"https:\/\/rumex.mendelu.cz\/oryx\/les_jako_ekosystem\/index.php\/wp-json\/wp\/v2\/media?parent=43"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
- – zachycen\u00e1 a absorbovan\u00e1 FAR – k odvozen\u00ed \u010dist\u00e9 prim\u00e1rn\u00ed produkce<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"
- \u2013 velk\u00e9 mno\u017estv\u00ed z\u00e1\u0159en\u00ed je absorbov\u00e1no, ale z t\u00e9to energie je pr\u016fm\u011brn\u011b pouh\u00e9 1% vyu\u017eito pro fotosynt\u00e9zu. V\u0161echna absorbovan\u00e1 energie s v\u00fdjimkou mal\u00e9 \u010d\u00e1sti v\u00e1zan\u00e9 fotosynt\u00e9zou je p\u0159em\u011bn\u011bna v teplo.<\/li>\n<\/ul>\n
- \u2013 zelen\u00e9 listy odr\u00e1\u017eej\u00ed p\u0159ibli\u017en\u011b 10\u201320% slune\u010dn\u00edch paprsk\u016f (v z\u00e1vislosti na postaven\u00ed list\u016f a povaze povrchu list\u016f)<\/li>\n<\/ul>\n