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812. Saranče horská - glaciální relikt a indikátor změn v prostředí
- Creator:
- Kuřavová, Kateřina
- Format:
- bez média and svazek
- Type:
- article, text, články, journal articles, model:article, and TEXT
- Subject:
- Biologické vědy, biologie, horské ekosystémy, bionomie, klimatické změny, mountain ecosystems, climate changes, biology, bionomy, glaciální relikt, herbivorní hmyz, glacial relict, herbivorous insects, 2, and 57/59
- Language:
- Czech
- Description:
- Saranče horská (Miramella alpina) patří mezi glaciální relikty, tedy živočichy osídlující velká území střední Evropy během dob ledových (glaciálů) v pleistocénu. Dnes je však jejich rozšíření většinou sporadické. Tyto druhy jsou přizpůsobeny k životu v extrémních podmínkách a u nás se vyskytují např. v horách nad hranicí lesa, v alpínských ekosystémech. Zde se musejí vypořádat s rychlou proměnlivostí prostředí (teplota nebo vítr) a s omezenou délkou vegetačního období. Saranče horská představuje jediný glaciální relikt ze skupiny rovnokřídlého hmyzu (Orthoptera) žijící v České republice. Vyskytuje se u nás v alpínském bezlesí Hrubého Jeseníku, kde může osídlovat i horské louky a paseky ve smrkových porostech, a dále obývá několik rašelinišť v jižních Čechách (např. Chlum u Třeboně, Vltavský luh - Mrtvý luh). Jde o evropský horský mezotopní druh rozšířený v Pyrenejích, Alpách a Karpatech, jenž nachází optimální podmínky pro život v subalpínském a alpínském stupni. K přežívání v podmínkách rašelinišť a horských bezlesých stanovišť od 500 do 2 200 m n. m. se výborně přizpůsobil a využívá hned několik strategií. Kvůli své potravní biologii a výskytu v alpínském bezlesí se saranče horská již několik let využívá při výzkumu vlivu zvýšeného množství oxidu uhličitého na bionomii herbivorního hmyzu v horských ekosystémech. Změny v koncentraci CO2 ve vzduchu vyvolávají totiž rozdíly v kvalitativním i kvantitativním zastoupení prvků a sloučenin v rostlinném těle a vedou k odchylné distribuci látek v listech. Herbivorové jsou tudíž těmito změnami prostřednictvím potravy ovlivňováni., Miramella alpina is a glacial relict, which occurred in large areas of central Europe during the ice ages in the Quaternary. This montane species lives in subalpine and alpine habitats, and is considered rare in the Czech Republic. Cryptic colouration, adaptation of the tarsi, food preferences and the onthogenetic cycle help the species to survive under extreme conditions. Due to its specific foraging biology it has been used as an excellent model in research on the effects of increased carbon dioxide concentration on the bionomics of herbivorous insects in mountain ecosystems., and Kateřina Kuřavová.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
813. Šavlozubí predátoři kenozoika. 1
- Creator:
- Knor, Stanislav
- Format:
- bez média and svazek
- Type:
- article, text, články, journal articles, model:article, and TEXT
- Subject:
- Biologické vědy, biologie, predátoři, evoluce (biologie), vyhynulí živočichové, kenozoikum, predators, biology, evolution (biology), extinct animals, cenozoic, šavlozubí, konvergentní evoluce, sabre-tooth, convergent evolution, 2, and 57/59
- Language:
- Czech
- Description:
- Opakovaný a nezávislý vznik i následná rozmanitost šavlozubých predátorů náležejí mezi nejpozoruhodnější jevy historie života na Zemi. Ti tak představují jedinečný příklad konvergentní evoluce, který zahrnuje celou řadu sdílených, velmi efektivních adaptací, vedoucích k jejich mimořádnému evolučnímu úspěchu. Důvod jejich zániku, ač k tomu v průběhu kenozoika došlo vícekrát, zůstává nejasný a poskytuje tím vděčný námět k četným spekulacím. Naposledy tento zajímavý ekomorfotyp vymizel z přírody zhruba před deseti tisíci lety. Snad ne navždy., Multiple independent origins and great diversity of sabre-tooth predators are one of the most remarkable phenomena in the natural history of life. Sabre-tooth predators provide a unique example of the convergent evolution that involved many kinds of very efficient functional adaptations leading to their unprecedented evolutionary success. The reason for their demise, although occurring repeatedly during the Tertiary, remains unclear and offers a broad matter of speculation. Nevertheless, this interesting ecomorphotype completely disappeared from nature roughly 10,000 years ago, but may be not for ever., and Stanislav Knor.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
814. Šavlozubí predátoři kenozoika. 2
- Creator:
- Knor, Stanislav
- Format:
- bez média and svazek
- Type:
- article, text, články, journal articles, model:article, and TEXT
- Subject:
- Biologické vědy, biologie, predátoři, neogén, pleistocén, kenozoikum, vyhynulí živočichové, kočkovití, šelmy, cenozoic, biology, predators, neogene, pleistocene, extinct animals, carnivora, Felidae, šavlozubí, Barbourofelidae, Carnivora, 2, and 57/59
- Language:
- Czech
- Description:
- V průběhu neogénu byli s výjimkou jihoamerických vačnatých thylakosmilidů po celém světě jedinými představiteli šavlozubého ekomorfotypu již pouze šelmy barbourofelidi (Barbourofelidae) a příslušníci čeledi kočkovitých (Felidae). Někteří z nich pak dosahovali značné velikosti a mimořádně robustní stavby těla, přičemž v těchto ohledech překonávali ty největší zástupce dnešních velkých koček. Zvláště šavlozubé kočky na dlouhou dobu obsadily pozici na vrcholu potravní pyramidy, než nakonec definitivně vymizely ke konci pleistocénu ze Severní a Jižní Ameriky. Ve Starém světě však vyhynuly již o něco dříve během čtvrtohor, zřejmě následkem zesílené vzájemné konkurence s velkými kočkami, především pak se lvy a tygry., During the Neogene, with the exception of thylacosmilids, barbourofelids and felids were the only representatives of the sabre--tooth ecomorphotype worldwide. Some of them attained tremendous size and were of very robust somatic constitution, exceeding in these aspects the largest contemporary cats. Especially the sabre-tooth felids occupied the top of the trophic chain for a long time before their demise at the end of the Pleistocene in both North and South America. But in the Old World these predators disappeared somewhat earlier, probably due to the strength of mutual competition with other large felids, namely the lions and tigers., and Stanislav Knor.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
815. Sazná nemoc kůry - hrozba pro naše kleny?
- Creator:
- Kelnarová, Ivana, Ondřej Koukol, and Černý, Karel
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Biologické vědy, mykologie, dřevokazné houby, javor, stromy, patogenní houby, mycology, wood-decaying fungi, maple, trees, pathogenic fungi, Praha (Česko), Prague (Czechia), sazná nemoc kůry, kůrová nekróza, patogeny, javor klen, kleny, Acer pseudoplatanus, Cryptostroma corticale, Sycamore trees, 2, and 57/59
- Language:
- Czech
- Description:
- Sazná nemoc kůry je méně známé onemocnění způsobené houbou Cryptostroma corticale (Ascomycota), s ostrůvkovitým výskytem v Evropě. Postihuje zejména javory kleny (Acer pseudoplatanus) a jejich hromadná vymírání byla zaznamenána u stromů oslabených stresem, především po nadprůměrně suchých a horkých letních měsících. Nedávný výskyt onemocnění v České republice podnítil studium druhu C. corticale a jeho rozšíření v Praze. Výsledek naší čtyřleté studie prokázal, že napadena je minimálně čtvrtina klenů v pražských parcích., Sooty bark disease is a less known disease caused by fungal species Cryptostroma corticale (Ascomycota), with patchy incidence in Europe. It mainly affects Sycamore (Acer pseudoplatanus), and its mass dieback was observed in trees weakened by stress, especially after the exceptionally dry and hot summer months. Recent record of the disease in the Czech Republic prompted the research of C. corticale and its occurrence in Prague. The results of our four-year study showed that at least 25 % of Sycamore trees in Prague parks are infected., and Ivana Kelnarová, Ondřej Koukol, Karel Černý.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
816. Sborník Bohemia centralis 32 - příroda Českého krasu
- Creator:
- Jarmila Kubíková
- Format:
- bez média and svazek
- Type:
- article, text, recenze, recensions, model:article, and TEXT
- Subject:
- Biologické vědy, biologie, biology, 2, and 57/59
- Language:
- Czech
- Description:
- [autor recenze] Jarmila Kubíková.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
817. Seasonal and interannual variations of ecosystem photosynthetic features in an alpine dwarf shrubland on the Qinghai-Tibetan Plateau, China
- Creator:
- Li, H. Q., Zhang, F. W., Li, Y. N., Cao, G. M., Zhao, L., and Zhao, X. Q.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, fenologie, photosynthesis, phenology, Čína západní, Tibet (Čína), China, Western, ecosystem photosynthetic parameters, eddy covariance technique, leaf area index, rectangular hyperbolic light response, 2, and 581
- Language:
- Multiple languages
- Description:
- Ecosystem photosynthetic characteristics are of utmost importance for the estimation of regional carbon budget, but such characteristics are not well understood in alpine regions. We collected CO2 flux data measured by eddy covariance technique over an alpine dwarf shrubland on the Qinghai-Tibetan Plateau during years 2003-2010; and we quantified the temporal patterns of ecosystem apparent quantum yield (a), saturated photosynthetic rate (Pmax), and ecosystem dark respiration (RDe). Results showed that the strong seasonality of a and RDe was driven mainly by air temperature (Ta), whereas that of Pmax was much more determined by leaf area index rather than abiotic factors. Diurnal thermal fluctuation inhibited significantly the daytime photosynthetic capacity. Stepwise regression revealed that the seasonal deviations of a, Pmax, and RDe were significantly controlled by Ta. The annual a was regulated mainly by annual growing season Ta, which indicated that the response of ecosystem a was instant. The annual variations of Pmax correlated positively with soil temperature 5 cm below ground (Ts) of the annual nongrowing season and those of RDe related negatively with the annual nongrowing season precipitation. We suggested that a lagged response regulated the annual Pmax and the annual RDe. Annual deviations of a and RDe were both significantly controlled by annual Ts, and those of Pmax were marginally determined by annual PPFD. Thus, the future warming scenario, especially significant for nongrowing seasonal warming in the Qinghai-Tibetan Plateau, would favor ecosystem photosynthetic capacity in the alpine dwarf shrubland., H. Q. Li, F. W. Zhang, Y. N. LI, G. M. Cao, L. Zhao, X. Q. Zhao., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
818. Seasonal dynamics of photosynthesis and total carbon gain in bearing and nonbearing pistachio (Pistacia vera L.) shoots
- Creator:
- Marino, G., La Mantia, M., Caruso, T., and Marra, F. P.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- alternativní ložisko, karbohydráty, křivka reakce na světlo, fotosyntetická hustota fotonového toku, alternate bearing, bud drop, carbohydrates, light-response curve, photosynthetic photon flux density, 2, and 581
- Language:
- Multiple languages
- Description:
- Seasonal changes in leaf gas exchange, assimilation response to light and leaf area were monitored in bearing and nonbearing pistachio shoots. Shoot bearing status did not directly affect leaf photosynthetic rate. However, photosynthetic light-response curves strongly varied during the season demonstrating the dominant effect of the tree’s seasonal phenology on assimilation. Early in the season low photosynthetic rates were associated with high rates of dark respiration indicating limited photosynthesis in the young leaves. As leaves matured, dark respiration decreased and assimilation reached maximum values. Photosynthetic efficiency was strongly reduced late in the season due to leaf age and senescence. Fruit load precipitated an early leaf senescence and drop that resulted in a 53% decrease in leaf area in bearing vs. nonbearing shoots, strongly decreasing the seasonal photosynthetic performance of bearing shoots. Bearing shoots produced a 26% lower seasonal carbon gain compared to nonbearing shoots., G. Marino, M. La Mantia, T. Caruso, F. P. Marra., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
819. Seasonal variation in photosynthesis performance of cassava at two different growth stages under irrigated and rain-fed conditions in a tropical savanna climate
- Creator:
- Vongcharoen, K., Santanoo, S., Banterng, P., Jogloy, S., Vorasoot, N., and Theerakulpisut, P.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, canopy, leaf gas exchange, light-response curve, Manihot esculenta, 2, and 581
- Language:
- Multiple languages
- Description:
- Seasonal variations in photosynthesis of cassava cv. Rayong 9 (RY9) under irrigated and rain-fed conditions were evaluated at the age of three and six months after planting (MAP). Photosynthetic light-response (PN/I) curves revealed that cassava leaves attained the highest maximum net photosynthetic rates (PNmax) in the rainy season, followed by the hot one, while the lowest PNmax was found in the cool season. Photosynthetic potential of the 3-month-old plants was mostly higher than that of the 6-month-old plants, and the seasonal variation in photosynthetic capacity was also more apparent in the younger plants. PN/I curves were used to predict daily net photosynthetic rate (PN) for each season based on daily average solar radiation data. The predicted PN were considerably lower than the PNmax values. This indicated that solar radiation is a limiting factor for photosynthesis, particularly in the rainy season. The data provided basic information for breeding cassava genotypes with enhanced photosynthesis during the period of unfavorable environment. Furthermore, the data are potentially useful in modeling photosynthesis and crop growth as affected by environmental factors., K. Vongcharoen, S. Santanoo, P. Banterng, S. Jogloy, N. Vorasoot, P. Theerakulpisut., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
820. Selenium delays leaf senescence in oilseed rape plants
- Creator:
- Rahmat, S., Hajiboland, R., and Sadeghzade, N.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- nitrát reduktázy, rychlost fotosyntézy, fluorescence chlorofylu, selen, řepka olejka, leaf photochemistry, nitrate reductase, photosynthetic rate, chlorophyll fluorescence, selenium, oilseed rape, 2, and 581
- Language:
- Multiple languages
- Description:
- Effect of selenium on leaf senescence was studied in oilseed rape plants treated with 10 μM Na2SeO4 at a rosette growth stage. In addition to developmental senescence, N deficiency and leaf detachment were used for induction of senescence. Nonphotochemical quenching declined in old leaves as senescence became more advancing but rose progressively in the plants supplied by Se. The total carbohydrate and protein pools decreased with leaf age, while increased by the Se treatment. However, during senescence induced by N deficiency, Se did not change remarkably the C and N metabolism, but delayed senescence mainly through protection of plants from photoinhibitory effects. After detachment, untreated leaves became chlorotic and necrotic, while the Se-treated ones remained fairly green. Our results demonstrated that Se delayed leaf senescence by a maintaining or even improving photochemical activities. During developmental senescence, the Se effect on the extending life span of the leaves was additionally linked to the metabolic regulation of senescence., S. Rahmat, R. Hajiboland, N. Sadeghzade., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public