V článku je popsán původ, domestikace a současný význam kapra obecného (Cyprinus carpio) jako nejdůležitějšího druhu rybničních chovů v Evropě. Stručně je vysvětlena technologie chovu kapra a její vlivy na ekosystémy rybníků., The origin, domestication process and present value of Common Carp (Cyprinus carpio) as the most important species in pond aquaculture in Europe is described. The technology of carp production and the impact of carp culture on the ecosystems of fishponds are briefly explained., Josef Matěna, Martin Flajšhans., and Obsahuj seznam literatury
Haldy (odvaly), které na Ostravsku vznikaly jako průvodní jev dolování černého uhlí v první polovině 20.stol, se již staly typickým krajinným prvkem této oblasti. Později zde byly snahy dolováním pozměněnou krajinu „uzdravit“ finančně nákladnými technickými rekultivacemi. Výstupy z našich studií prokázaly, že spontánní sukcese na nerekultivovaných haldách probíhá rychleji a společenstva bezobratlých jsou zde lépe strukturovaná. Navíc nerekultivované haldy podporují populace ochranářsky cenných druhů bezobratlých. Jednoznačně proto doporučujeme haldy ponechat spontánní sukcesi, před finančně náročnými technicky vedenými rekultivacemi., The spoil heaps in Ostrava were created during mining of black coal in the first half of the 20th century. Later, there were efforts to “heal” the landscape by technical reclamations, which are rather expensive. Our studies showed that spontaneous succession on non-reclaimed spoil heaps is faster then succession on their reclaimed counterparts. The communities of invertebrates on non-reclaimed spoil heaps are also more mature and contain rare species in comparison with the reclaimed ones., and Jiří Hodeček, Tomáš Kuras.
The honey bee is usually thought of as a key pollinator in cultural landscapes. Our results evidence that although it may be the most abundant, its importance is lower compared to hoverflies and bumblebees both in terms of the pollinated plant species number and the spectrum of vegetation types covered. The broad spectrum of hoverfly diets suggests the cause of their high importance as pollinators. and Zdeněk Janovský.
Herbivorous insects are often highly specialised, likely due to trade-offs in fitness on alternative host species. However, some pest insects are extremely adaptable and readily adopt novel hosts, sometimes causing rapid expansion of their host range as they spread from their original host and geographic origin. The genetic basis of this phenomenon is poorly understood, limiting our ability to predict or mitigate global insect pest outbreaks. We investigated the trajectory of early adaptation to novel hosts in a regionally-specialised global crop pest species (the cowpea seed beetle Callosobruchus maculatus). After experimentally-enforced dietary specialisation for nearly 300 generations, we measured changes in fitness over the first 5 generations of adaptation to 6 novel hosts. Of these, C. maculatus reproduced successfully on all but one, with reduced fitness observed on three hosts in the first generation. Loss of fitness was followed by very rapid, decelerating increases in fitness over the first 1-5 generations, resulting in comparable levels of population fitness to that observed on the original host after 5 generations. Heritability of fitness on novel hosts was high. Adaptation occurred primarily via changes in behavioural and phenological traits, and never via changes in offspring survival to adulthood, despite high heritability for this trait. These results suggest that C. maculatus possesses ample additive genetic variation for very rapid host shifts, despite a prolonged period of enforced specialization, and also suggest that some previously-inferred environmental maternal effects on host use may in part actually represent (rapidly) evolved changes. We highlight the need to examine in more detail the genetic architecture facilitating retention of high additive genetic variation for host shifts in extremely adaptable global crop pests., Thomas N. Price, Aoife Leonard, Lesley T. Lancaster., and Obsahuje bibliografii
Giant rosettes are ones of the most striking features of the vegetation in the high tropical Andes, with Coespeletia moritziana reaching the highest altitudes up to 4,600 m a.s.l. Different from other giant rosettes, this species grows on rock outcrops with poorly developed soils and where water availability may be limited. Two questions are addressed in this study: How does this species respond in terms of water relations to maintain favorable gas-exchange conditions? Considering that adult plants rely on a water-reserving central pith, how do early stages respond to this environment’s extreme conditions? Water relations and gas-exchange studies were carried out on juveniles, intermediate and adult C. moritziana plants during wet and dry seasons in Páramo de Piedras Blancas at 4,200 m a.s.l. Adult plants maintained higher leaf water potentials (ΨL) during the wet season, however, no differences between stages were found for the dry season. Minimum dry season ΨL were never near the turgor loss point in any of the stages. Juveniles show a more strict stomatal control during the dry season to maintain a favorable water status. Net photosynthesis significantly decreased in intermediate and juvenile stages from wet to dry seasons. Our results suggest that
C. moritziana resists more extreme conditions compared to other Andean giant rosettes., F. Rada, A. Azócar, A. Rojas-Altuve., and Obsahuje bibliografii