Příspěvek se zabývá a) vztahem pravěkého osídlení k půdám na území dnešních Čech, b) vztahem mezi obilninami pěstovanými v pravěku a vybranými parametry přírodního prostředí, zejména půdní produktivity, na území celé České republiky. Vztahy archeologických období a půdních typů se dají na úrovni makroregionu rozdělit do čtyř skupin, které v zásadě odpovídají vývoji pravěkého orebního zemědělství. Všechny zemědělské kultury přednostně využívaly oblasti kvalitních půd, ale byly schopné hospodařit i na půdách s nižší kvalitou. Silná vazba osídlení a nejlepších orebně zemědělských půd přestává platit v průběhu mladší fáze starší doby bronzové, ale opět se projevuje v závěru pravěku zejména v době stěhování národů. Nejdůležitější environmentální proměnnou, která ovlivňuje složení pravěkých souborů pěstovaných obilnin je kvalita půdy. To je nejvíce patrné na poměru pěstovaných pšenic a ječmene: s klesající půdní kvalitou stoupá podíl ječmene a klesá podíl pšenic. Ačkoliv ekologické nároky pravěkých obilnin nejsou známy, ukazuje se, že prospívaly za podobných podmínek jako dnešní odrůdy a strategie pravěkého zemědělství byla podobná dnešním neindustriálním zemědělským komunitám, to znamená dosažení stabilní úrody pomocí vhodného výběru optimálních plodin vzhledem k lokálním podmínkám. and The study deals with: a) the relationship between prehistoric settlement and soil within the territory of today’s Bohemia, b) the relationship between cereals grown in prehistory and selected parameters of the environment, specifically the soil productivity, throughout the territory of the whole Czech Republic. The relations between archaeological periods/cultures and soil types on the level of macro-region can be divided into four groups generally corresponding the development of prehistoric arable agriculture. All prehistoric cultures using arable farming as the main subsistence strategy settled preferentially high-quality soil regions. However, they were able to farm on lower quality soils, too. The strong bond between settlement and the best arable soils ceased to apply during the later phase of the Early Bronze Age but it reappeared at the end of prehistory, especially during the Migration period. The most important environmental variable influencing the composition of cereals preserved within prehistoric macroremains assemblages is the quality of soil. This is manifested by the proportional representation of cultivated wheat and barley: as the soil quality goes down, the ratio of barley increases, while wheat decreases. Though the environmental demands of prehistoric cereals are not known, it turns out, that they thrived under similar conditions as current varieties and, moreover, the strategy of prehistoric arable farming was similar to present-day non-industrial farming communities, e.g. the stable yield was achieved through adequate choice of optimal crops corresponding local conditions.
The objective of this work was to compare the effect of selected feed mixtures on the duodenal morphology. One-hundred-four rats of the Wistar strain were divided to thirteen groups per eight rats. The experiment started in 35-day-old rats after birth and lasted for 32 days. The groups (A-M) were fed by commercial diet, 85 % wheat and 15 % oat diet, 85 % wheat and 15 % triticale, 85 % wheat and 15 % barley, 85 % wheat and 15 % amaranth, 85 % wheat and 15 % lantern, 85 % wheat and 15 % buckwheat, 100 % wheat, 100 % white lupine, 100 % flock peas – variety Garden, 100 % native peas – variety Garden, 100 % native peas – variety Zekon or 100 % extruded peas – variety Zekon diet, respectively. Samples from the duodenum were taken. The height of the villi and the depth of the crypts were measured. The tallest villi were measured in group F (474.33±114.36 µm) and the shortest villi were observed in group B (294.08±88.52 µm). The deepest crypts were measured in group K (166.41±35.69 µm) and the shallowest crypts were observed in group E (77.85±17.61 µm). The work documents that gluten-free and classical cereals combination can be a better choice for people who want to limit the gluten content of the diet.
The duration of the increase, peak and decline in abundance of the immature stages of sycamore and cereal aphids each year is ephemeral. These temporary resources are exploited by a sequence of aphidophagous insect predators. The temporal sequence in the appearance of the immature stages of coccinellids and syrphids in the sycamore and cereal aphid systems is defined. In spring in the sycamore aphid system and early summer in the cereal aphid system the immature stages of syrphids consistently appeared before those of coccinellids. In the case of the sycamore aphid the autumnal peak in abundance was on average larger than the spring peak, and although attacked by more syrphids, it was not exploited by coccinellids. These temporal patterns in the attack sequence are associated with a difference in the lower developmental thresholds (LDT) of these two groups of predators. The LDT of syrphids (4°C) enables them to be active at lower temperatures and to develop faster between 10° and 27°C than coccinellids, whose LDT is 10°C. As a consequence, early in the year, when temperatures are low but increasing, syrphids appear before and complete their development more quickly than coccinellids, and in the latter half of the year, when temperatures are generally lower and decreasing, only syrphids are likely to be able to complete their development before the aphids disappear. Thus, the niche shift between syrphids and coccinellids is possibly more a consequence of a phylogenetic constraint than a response to competition and or intraguild predation. The relevance of these findings for the ecology of intraguild predation is discussed.