Morphological and physiological traits of Crepis pygmaea L. subsp. pygmaea and Isatis apennina Ten. ex Grande growing at different altitudes in the Gran Sasso Massif (Abruzzo, Italy) were analyzed. The two populations of C. pygmaea and I. apennina growing at the highest altitude (Cp2 and Ip2 at 2,310 m a.s.l. and 2,350 m a.s.l., respectively) had a lower leaf mass area (LMA) than the two populations growing at the lowest altitude (Cp1 and Ip1 at 2,250 m a.s.l. and 2,310 m a.s.l., respectively). Leaf tissue density (LTD) had the same LMA trend, decreasing 23 and 10% in C. pygmaea and I. apennina, respectively, from the highest to the lowest altitude. C. pygmaea and I. apennina had the highest photosynthetic rates
(PN) in July decreasing on an average 17 and 30%, respectively, in August and 50 and 38%, respectively, in September. Leaf respiration (R) in Ip1 and Ip2 had the same trend as Cp1 and Cp2, showing the highest rates in September. Global warming could drive C. pygmaea and I. apennina toward higher altitudes in the Gran Sasso Massif. Nevertheless, C. pygmaea with the higher plasticity index (PI) both at physiological and at morphological levels (0.50 and 0.35, respectively) might have a competitive advantage over I. apennina over the long term., L. Gratani ... [et al.]., and Obsahuje bibliografii
a1_The study of plant responses to environmental stress factors is essential for management of plant systems and for anticipating their response to climate change. The main goal of this study was to determine morphological and physiological responses of Nothofagus obliqua and N. nervosa seedlings to light and temperature, two of the main stress factors acting in their current natural distribution in NW Patagonia. Responses to light were evaluated analyzing growth and survival, as well as morphological and physiological traits related to them, in seedlings subjected to three contrasting light conditions (full-sun conditions, 50% of sunlight and 20% of sunlight) during one growth season. Temperature photosynthetic responses were evaluated in seedlings subjected to temperature treatments between -5 and 40°C for 2 and 4 h. Growth rate and biomass partition were similar between light treatments in both species. High apical meristem damage and decreased photosynthetic capacity of preformed leaves were observed under full-sun conditions, suggesting that high light levels have a deleterious effect on plant yield. Both species produced neoformed leaves during the growing season with better photosynthetic capacity than preformed leaves under full sun conditions, contributing to plant acclimation. Almost no plasticity was observed in morphological traits in response to shade. Both species differed in optimum temperature for photosynthesis, with a wider temperature range at which high photosynthesis is maintained in N. obliqua. In both species the higher values of net photosynthetic rate were found at higher temperatures than the mean annual temperature of its current natural distribution range., a2_Under no water-stress conditions, future higher temperatures could increase carbon fixation of these species, with a little advantage of N. obliqua if temperature variance is high. Synergy effect of various environmental stress factors, particularly considering cultivation of these species outside their current natural distribution sites require further studies., S. A. Varela ... [et al.]., and Obsahuje bibliografii
The diversity of lichen flora is presented and compared with the neighbouring count - ries. The main phytogeographic elements are outlined and illustrated with representative examples. Changes in the flora along with the main causal factors are discussed. and Jiří Liška.
Botanical knowledge can be directly applied especially in nature conservation and ecological restoration. Extensive field experience, good knowledge of plants and thorough theoretical background are important prerequisites. Some applications are also possible in the agricultural, forestry, pharmacy, food and textile industries. and Karel Prach.
napsal V. Melzer, Obsahuje abecední seznam hub, klíč k určení našich nejdůležitějších hub jedlých i jedovatých s návodem, jak jich upotřebiti v kuchyni a hospodářství, and Converted from MODS to DC version 1.8 (EE patch 2018/05/24)
Predace semen je strategie, kdy živočich za účelem obživy napadá a zničí mnoho semen rostlin. V tomto krátkém sdělení přibližujeme aktuální poznatky o střevlíkovitých predátorech semen po uvolnění z rostliny. Střevlíkovití brouci zpravidla preferují semena odpovídající velikosti jejich těla, výběr druhů preferovaných semen je však pro daný druh střevlíka typický a během sezony se nemění. Během sezony značně kolísá množství spotřebovaných semen, za optimálních podmínek vysoké hojnosti a aktivity brouků může být denně zničeno až 1000 semen na ploše 1 m2. Střevlíkovití přitom preferují semena hvězdnicovitých rostlin (Asteraceae), jako jsou pampelišky (Taraxacum sect. Ruderalia) nebo pcháč oset (Cirsium arvense), dále semena brukvovitých (Brassicaceae), jako je kokoška pastuší tobolka (Capsella bursa-pastoris). Střevlíkovití tak přispívají k udržení biologické rovnováhy., Seed predation is a strategy where an animal attacks and kills the seeds of plants. In this contribution we report on the latest knowledge on carabid beetles (Carabidae) feeding on seeds after dispersal from the plant. In general, carabid beetles prefer seeds of appropriate size to their body size, but the selection of seed species is species-specific and remains stable across the season. The consumption considerably varies throughout the year, and under optimal conditions the carabid beetles may destroy up to 1000 seeds per 1 m2. Carabid beetles prefer seeds of Asteraceae, such as Dandelion (Taraxacum) or Canadian Thistle (Cirsium arvense), and of Brassicaceae, such as the Shepherd’s Purse (Capsella bursa-pastoris). In this way the carabid beetles contribute to the balance in ecosystems., and Pavel Saska, Alois Honěk, Zdenka Martinková.
Anthoxanthum odoratum (Sweet Vernal Grass), is a widespread grass species native to Eurasia and common also in the Czech Republic. Its name is derived from distinct scent, particularly strong in dry state, caused by coumarins. Eight other Anthoxanthum species can be found in Europe, one of which (A. alpinum) occurs in the Czech Republic. It replaces A. odoratum at higher altitudes. The genus encompasses both di - ploids and polyploids that have complex evolutionary history. We used DNA flow cytometry together with molecular markers to gain detailed insights into evolutionary processes shaping the genus. and Zuzana Khodlová, Pavel Trávníček.
Results of the long-term monitoring of spontaneous development in mountain Norway Spruce (Picea abies) forest in the Šumava Mts. after Bark Beetle (Ips typographus) gradation and windthrows are presented. The aim is to show the key role of natural disturbances for this ecosystem. and Magda Edwards Jonášová.
Converted from MARCXML to MODS version 3.5 using MARC21slim2MODS3-5.xsl (Revision 1.106 2014/12/19)(EE patch 2015/05/15), Upravili Josef Groulík a Josef Úlehla, ředitelé při školách měšťanských, Druhý stupeň, and Converted from MODS 3.5 to DC version 1.8 (EE patch 2015/06/25)