Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 7

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  browsing
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
1
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Influence of initial light intensity and deer browsing on Taxus baccata saplings: a six years field study

100%
Iszkulo G., Nowak-Dyjeta K., Sekiewicz M.
Dendrobiology
|
2014
|
tom 71
European yew (Taxus baccata L.) is a rare species, but is the focus of great interest because of the species recovery attempts and its use in medicine. The aim of this study was to determine the optimum conditions for the development of the young generation of this species. Four-year old yew seedlings were grown under artificial light reduction: 2, 8, and 30%, as well as in full light. The seedlings were then planted in natural conditions in fenced and unfenced areas. The results of six years field studies indicated that the greatest impact on survival was shown by the light conditions from the period before planting under the canopy of trees. Seedlings from the 2 and 8% of light showed the greatest mortality. The reason was the sudden change in light conditions, because at the time of planting (early spring), there was no reduction of light under deciduous trees. Almost all of the unfenced yew seedlings were grazed by deer, but yew survival in the unfenced group was surprisingly high despite the permanent grazing. This was explained by the high resistance of yew to cutting and the protection of seedlings by a dense layer of Rubus. The results indicated that yew trees require protection against animals for normal development, even if animals have not previously had contact with Taxus and that yew seedlings are very sensitive to sudden changes in light. Both conclusions can be applied in the development of natural and artificial regeneration of European yew and other endangered plants.
2

Foraging behavior and spatial use of a rock specialist: the southern vizcacha (Lagidium viscacia), and the exotic European hare (Lepus europaeus) in rocky outcrops of northwestern Patagonia, Argentina

80%
Galende G. I., Raffaele E.
Acta Theriologica
|
2013
|
tom 58
|
nr 3
The southern vizcacha (Lagidium viscacia) and the exotic European hare (Lepus europaeus) are two medium-sized herbivores that inhabit rocky outcrops in Patagonian steppe. These species overlap in diet and spatial use at medium distances from rocky outcrops in summer. We evaluated the spatial use through feces distribution in winter and determined seasonal foraging intensity in relation to the distances from rocky outcrops in order to elucidate how these herbivores use food and spatial resources in food scarcity periods. The vizcacha utilized the habitat close to rocky outcrops (<40 m) independent of season, while the hare exploited the space more widely, especially distances >40 m. However, in winter, at medium distances from rocky outcrops, there was partial spatial overlap because hares' activities were closer to rocky outcrops. Foraging intensity increased significantly in areas used by the vizcacha closer to rocky outcrops when food availability decreased, and the grasses Stipa speciosa, Poa sp., and Festuca pallescens were strongly foraged. In contrast, foraging intensity showed no changes in further distances to rocky outcrops and more use by the hare. The spatial and feeding behavior of the vizcacha, restricted to vicinity of rocky outcrops, showed high vulnerability to food availability changes. In resource scarcity situations, the spatial opportunistic behavior of the hare and the overlap in diet with the vizcacha constitutes a threat to this native herbivore. It is necessary to monitor populations of hare, since high densities could lead to food competition, impacting the small colonies of the southern vizcacha.
3
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

The spatial pattern and microsites requirements of Abies alba natural regeneration in the Karkonosze Mountains

80%
Szymura T. H., Dunajski A., Aman I., Makowski M., Szymura M.
Dendrobiology
|
2007
|
tom 58
51-57
Progeny of four adult silver firs, which were an admixture in Norway spruce (Picea abies) stand was, analyzed. The study was done in lower mountain zone of the Karkonosze (Giant Mts.) National Park (SW Poland). The seedlings occurred in two clumps related to the position of adult trees, whereas spatial pattern of the seedlings inside each clump was random. The seedlings were spaced mainly in distances 5–25 from the nearest adult tree. The maximal distance was up to 50 m. Most seedlings were established in accordance with main wind directions. Also, in these directions seedlings were more distant from adult trees than in other directions. The seedlings grew in better light environment (12% of PPFD) than average (9,6% PPFD). This effect was statistically significant. The height increment of the seedlings was low and was not correlated with light conditions. Similarly, there was not any correlation between the apical dominance ratio and light. The lack of this correspondence we attributed to browsing. The silver fir seedlings were significantly underrepresented in patches of Vaccinium myrtillus, on raw needles, under crown of adult trees and in concave micro-relief form. The underrepresentation in the places covered by canopy and in patches of bilberry we related to the indirect effect of continuous browsing, which leads to higher seedlings mortality in more shaded places and sites of stronger competition between forest floor vegetation and silver fir seedlings.
4

Seasonal diet of rabbits and their browsing effect on juniper in Bugac Juniper Forest [Hungary]

80%
Matrai K., Altbacker V., Hahn I.
Acta Theriologica
|
1998
|
tom 43
|
nr 1
Seasonal foods of European rabbits Oryctolagus cuniculus (Linnaeus, 1758) were studied by microhistological analysis of pellets in a protected area Bugac Juniper Forest, Hungary. Field experiments were also conducted to examine the role of rabbit foraging on common juniper Juniperus communis. The proportion of grasses, forbs and browses changed significantly throughout the seasons (p < 0.0001). Spring diet was dominated by grasses (89%), summer diet by grasses (30%) and forbs (42%), whereas in autumn grasses (60%) and browse (24%) were the main diet components. Juniper appeared only in winter diet (19%) together with other browse (60%). The high proportion of aromatic thyme Thymus glabrescens in summer diet (30%) and juniper in winter diet indicates that monoterpenoids of these plants did not keep rabbits from consumption even when other food sources were available. Planted juniper seedlings disappeared within weeks due to the browsing by rabbits.
5

Effect of deer and other environmental factors on growth of pine cultures in the Zielonka' Experimental Forest Division

80%
Labudzki L., Fruzinski B., Skubis J.
Acta Scientiarum Polonorum. Silvarum Colendarum Ratio et Industria Lignaria
|
2002
|
tom 01
|
nr 2
6

Moose browsing on pine and willow in the Biebrza Valley, Poland

80%
Borkowska A., Konopko A.
Acta Theriologica
|
1994
|
tom 39
|
nr 4
Utilization of browse supply and moose Aices alces Linnaeus, 1758 browsing intensity in relation to tree height (0.5-3.0 m) were estimated for Scots pine in thickets and willow in willow-birch shrubs. The thickets examined provided different browse resources (0.5, 2.0 and 3.2 t dry wt/ha) and the highest utilization (about 50%) was found in the poorest one (thicket 1). In the willow-birch shrubs the use of browse was high and amounted to 85% of total production in both the winter periods studied. The number and increase of biomass of browsed twigs per stem (or plot} was generally associated with the increase of tree height. Browsing intensity depended on the tree height. Pines of 1.5-1.99 m height were characterized by the greatest browse utiliza­tion (76.3%). Moose removed significantly more biomass and twigs from pines growing in the central zone of the thicket 1 than from those growing in the marginal zone. However, in the wiilow-birch shrubs the utilization of all tree height classes was above 70% of the production and moose browsed not only the last year's growth of shoots but also that of earlier years.
7

Palatability estimation of the trees by the sheep on the pastures

61%
Gasiorek S., Kostuch R.
Acta Agraria et Silvestria. Series Zootechnica
|
1997
|
tom 35
29-32
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.