Vilém Pavlů

Sward structure and diet selection after sheep introduction on abandoned grassland in the Giant Mts, Czech Republic

The effect of rotational grazing on the sward structure of long-term abandoned grassland and the sheep diet selection were investigated in the Giant Mts (Krkonoše/Karkonosze). The aim of the study was to answer the following questions: (1) Does sheep grazing affect the sward structure of previously abandoned mountain grassland? (2) How does sheep diet selection develop within and among grazing seasons? (3) Which section of a pasture do sheep prefer to graze? Data was collected three times during each grazing season in spring, summer and in autumn in the years 2001, 2002 and 2003 Fifty 1 × 1 m plots were used where the plant species occurrence and damage of plants by grazing for all species were repeatedly recorded. 1) Nonsignificant changes in plant species occurrences were recorded in spite of obvious visual changes in sward structure due to grazing e.g. the retreat of tall dominant species characteristic of long-term unmanaged grasslands. 2) Seasonal as well as inter-annual changes in sheep diet selection were detected. In spring 2001, sheep grazed over a wide variety of plant species in low quantities. In subsequent springs, they preferred species favoured during previous autumns (Veratrum album subsp. lobelianum; Ranunculus platanifolius; Senecio ovatus) and changed the diet only as a result of the elimination of favoured plants. 3) Sheep preferred to graze at the highest elevated part of the pasture probably as a consequence of anti-predator behaviour not due to higher occurrence of favoured plant species or the presence of a drinking place or salt licks. Changes in the sward structure were mostly of a quantitative not qualitative character, thus the presence-absence data collection is not a suitable method for monitoring the effects of management restoration. The diet selection changed probably due to the animals’ experience; sheep had no experience with montane species in spring 2001. The sheep were able to recognize favoured plant species after 6 months of wintering in lowland.

Nutritive value of winter-collected annual twigs of main European woody species, mistletoe and ivy and its possible consequences for winter foddering of livestock in prehistory:

In Central Europe, forest grazing was probably the main way of providing winter feeding for livestock in prehistory; the main components of this diet most likely included annual twigs of woody species (Acer platanoides, Betula pendula, Carpinus betulus, Corylus avellana, Fagus sylvatica, Fraxinus excelsior, Picea abies, Pinus sylvestris, Populus tremula, Quercus robur, Salix caprea, Tilia cordata and Ulmus glabra), Hedera helix, Viscum album and senescent grassland biomass; however, their nutritive value has never been compared. Biomass samples were collected in the Czech Republic in February 2013 and analysed for concentration of nitrogen, phosphorus, potassium, calcium, magnesium, fibre and lignin. With the help of a recent analogy from the Altai Mountains (Russia), possible consequences of winter grazing on the development of forest vegetation and cattle breeds in prehistory were assessed. Hedera and Viscum were the best forage available in winter, and their nutritive value, according to the highest N and lowest fibre and lignin concentrations, was higher than the nutritive value of all winter-collected annual twigs of woody species. Nutritive value of annual twigs of all woody species was very low, especially compared with the quality of meadow hay, leaf-fodder or senescent steppe grassland biomass. Therefore, Hedera and Viscum might have been preferentially grazed by livestock and collected by ancient farmers for the supplementary feeding of privileged animals. According to recent analogy, annual twigs of woody species were browsed by livestock. Their insufficient quality could be one of the reasons for the low body size of cattle recorded in prehistory. The most realistic model of livestock breeding in prehistory seems to be year-round grazing, opening forests and causing deforestation in the surroundings of prehistoric settlements.

Cover estimation versus density counting in species-rich pasture under different grazing intensities

Two methods for monitoring of grassland vegetation were compared: visual estimation of plant cover (C) and plant densities counting (D). C and D were performed in monthly intervals for three vegetation growing seasons after imposing different grazing regimes on abandoned grassland in 1998. Species scores obtained from paired redundancy analyses (RDA) of C and D data were compared and Spearman’s rank correlations were used to show if the two methods give comparable results. Results of C and D were highly correlated in the first two growing seasons only. In the third season, correlation was substantially lower as the sward structure was more heterogeneous due to creation of differently defoliated patches especially under extensive grazing. Presence of the same plant species with different habit in frequently and in infrequently grazed patches, reduced significance of Spearman’s rank correlations. Cover estimation can fully substitute plant density counting in grassland with lower proportion of frequently and infrequently grazed patches only, but caution should be used when comparing different management regimes in long term analyses.

Sward-height patches under intensive and extensive grazing density in an Agrostis capillaris grassland

Patchiness is one of the important features of grazed temperate grasslands, but little is known about the structure of sward height patches under different grazing intensities. The present study examined the effect of continuous intensive and extensive stocking of heifers on the proportions of sward-height patch categories (short ≤ 5cm, moderate 5.5–10 cm, tall ≥ 10.5 cm) and their plant species composition in an Agrostis capillaris grassland. A four-year study was performed on an upland grassland maintained under a long-term grazing experiment in the Jizerské hory Mts (Jizera Mountains), Czech Republic. The contrasting stocking densities form the differences in the proportion of sward-patch categories and generated a similar level of patch heterogeneity, which was mainly affected by the proportion of tall- and short-sward patches. The floristic composition of patches within the same sward height category depended upon stocking density. Moderate and tall patches under a given stocking density had similar botanical composition. Vegetation within short patches differed considerably from that of other patches under extensive grazing whereas under intensive grazing the differences between short, moderate and tall sward-height patches were small. The findings show that grazing intensity is a key driver of the proportion as well as the floristic composition of sward-height patches in grasslands dominated by A. capillaris. These findings have implications for nature conservation, as they support the recommendation for extensive management of upland grasslands.

Assessment of the impacts of municipal solid waste dumps on soils and plants

ABSTRACT The study aimed at evaluating the impacts of open municipal solid wastes dumps on soil and vegetation near the main roads linking major cities in Nigeria. We hypothesised that the metals from the wastes exerted substantial impacts at the dump sites which affect the soil and plants. Data were analysed from five dump sites and five control sites. The result revealed that the effects of the heavy metals (HM) were significant and higher at the dump sites where their concentrations were far above the EU, and Canadian environmental quality permissible limits for agricultural soils and vegetation. In contrast with dump sites, a significant relationship (R2 = 0.70; p < .001) was found between the number of plant species and area at control sites. Shrubs and herbs were more tolerance with higher contents of HM compared with grasses. Plants leaves showed more HM contents compared to the shoots or roots. The soil and plants contents of the HM were relatively in the order of Zn > Cr > Pb at both dump sites and control sites. Further study on the effects of more HM on soil and plant is recommended in the area. Recycling and bio-phytoremediation processes should also be introduced.