Status zagrożonych gatunków chwastów na ścierniskach zbożowych Kielecczyzny

Abstract

At the stubble-fields, especially maintained through a long period after the cereal harvest, there are numerous segetal flora species which often are not meet in the crop canopy. A status of these flora species is usually different than in crop canopies. The cereals, as the cultivated plants, undergo different weed control field operations which limit the level of weed infestation or even eliminate some of the weed species from a canopy. The stubble-field conditions (warmth, light, rain and lack of competition) are conducive to weed emerging from soil seed bank as well as growing up and ending reproduction of those present in vegetation. It seems that stubble-field flora could be an important and rich source of information about species listed or suspected as endangered with extinction. In respect of the Polish endangered weed species list, 43 weed species were found on different soil units in the Kielce region. Only about 70% of them had diaspores in the soil (some with soil seeds were absent in overground regions). Most species in the E, V, and R categories of threat shoved critically low stability degrees and indice covers. However, from the indeterminate threat group, I, a few occured in high (III—IV) stability degree and deposited huge numbers of seeds in the 0-30 cm soil layer.