Nitrogen deposition is generally considered as a main reason for many recent plant expansions, but management changes are often not taken into account. Understanding the effects of agriculture management in the past can be decisive in the explanation of plant expansions at present. In order to understand the spread of Molinia caerulea and Calamagrostis villosa into Nardus stricta dominated subalpine grassland in the Giant Mts. (Krkonoše, Karkonosze), we undertook an experiment to explain farmer decision making and we discussed its effect on grassland succession. We measured mowing productivity, yields, biomass quality and nutrient removal in N. stricta, M. caerulea, and C. villosa dominated swards. With regard to defoliation management performed on the subalpine grasslands for at least 500 years and cancelled after the Second World War, we found the following results and conclusions. 1. Mowing productivity, yield and forage quality were lowest in the N. stricta sward, therefore farmers preferred to harvest C. villosa and M. caerulea stands if they had the possibility to select a sward for mowing. 2. Removal of all nutrients was the lowest in the N. stricta sward. With respect to these facts, the competitive advantage of N. stricta is obvious under long-term scything without fertilization. Consequently, the recent increase of defoliation sensitive species M. caerulea and C. villosa above the timber line must be evaluated with respect to both: termination of agricultural activities and recent nitrogen deposition.
Seasonal composition and quality of diets of red deer Cervus elaphus Linnaeus, 1758 were investigated, basing on microhistolagical analysis of composite fecal samples in the Less Xingan Mountains, northeastern China. Red deer consumed more graminoids (46%) in spring, shifted to forbs (45%) in summer, and returned to graminoids (35%) in autumn. Availability and high quality [high level of crude protein (CP), and low level of neutral detergent fiber (NDF) and acid detergent fiber (ADF) in farbs in summer] appeared to be two key factors causing these changes in diets. Winter diets were dominated by browses (74%) and the horsetails Equisetum hiernale (21%). Three forbs (Oxalix corniculata, Caltha palustris, Agrimonia pilosa) were prevalent in diets during snow-free seasons, and aspen (Populus spp.) was an important browse species in all seasons, especially in winter (32%). Forage and diet quality changed seasonally. Dietary CP and in vitro dry matter digestibility (IVDMD) declined significantly from spring to winter (from 19.6 to 6.4% and from 61.1 to 32.9%, respectively). In contrast, dietary NDF and ADF increased from 55.6 to 69.9% and from 27.9 to 54.3%, respectively. Red deer diets showed different patterns of seasonal variation in mineral contents. In most cases, dietary Ca, P and K were adequate, but Na appeared deficient all the year round. It is concluded that red deer in this region are typical mixed feeders and their diet shows seasonal changes in quality, similar to those of North American wapiti. Although red deer may have enough protein in most seasons, energy might be a key limiting factor in severe winters.
In this review article, factors determining the sward utilisation of winter pasture in cattle feeding were defined and analyzed. The results from literature and own investigations have shown that yield and quality of autumn-saved herbage on winter pasture are determined by pratotechnical measures such as harvest date in winter and pre-utilisation date in summer, botanical composition of sward, and particularly the dominated grass species or community, nitrogen fertilisation and weather conditions in winter. The date of winter harvest as a dominating factor affects the development of dry matter yield as well as the digestibility of organic matter and nutrients concentration in herbage during winter. For the management of winter grazing systems it could be obtained that crude protein and energy concentration of the tested autumn-saved herbage met the requirements of suckler cows or beef cattle until the end of the year if they were pre-utilised in July. The weather conditions during autumn-winter period are important factor determining the accumulation of secondary metabolites formed by field fungi in herbage of winter pasture.