Articles containing the keyword 'browsing'

Moose (Alces alces L.) browsing was studied in young Scots pine (Pinus sylvestris L.) stands mixed with deciduous trees in high-density winter ranges. The proportional use of twig biomass decreased as the availability increased. The total as well as proportional biomass consumption were higher on the moist than on the dry type of forest. The per tree consumption of pine was higher on the moist type, where the availability of pine was lower. Deciduous trees were more consumed on the moist type, where their availability was relatively high. The consumption of pine saplings increased as the availability of birch increased. Pine stem breakages were most numerous when birch occurred as overgrowth above pine and at high birch densities. The availability of other deciduous tree species did not correlate with browsing intensity of Scots pine. Moose browsing had seriously inhibited the development of Scots pines in 6% of the stands, over 60% of available biomass having been removed. Rowan and aspen were commonly over-browsed and their height growth was inhibited, which occurred rarely by birch. There was no difference in the proportion of young stands in forest areas with high and low moose density. A high proportion of peatland forests was found to indicate relatively good feeding habitats in the high-density areas.

The PDF includes an abstract in Finnish.

• Heikkilä, E-mail: rh@mm.unknown
• Härkönen, E-mail: sh@mm.unknown

The efficacy of pine tar as a moose (Alces alces L.) contact repellent was tested in young Scots pine (Pinus sylvestris L.) stands suffering from moose damage in Southern Finland during the winter 1981–82. Application of tar to shoots by spraying protected the trees satisfactorily throughout the winter.

The PDF includes an abstract in Finnish.

• Löyttyniemi, E-mail: kl@mm.unknown
• Heikkilä, E-mail: rh@mm.unknown
• Repo, E-mail: sr@mm.unknown

The light reflected from the crowns of Scots pine (Pinus sylvestris L.) clones was measured spectroradiometrically during and after growing season. Standard deviations of the spectra of pine clones showing differences in moose browsing intensity were compared. A new algorithm was developed for predicting the browsing intensity of moose (Alces alces).

The PDF includes an abstract in Finnish.

• Silvennoinen, E-mail: rs@mm.unknown
• Hämäläinen, E-mail: rh@mm.unknown
• Nygrén, E-mail: kn@mm.unknown
• Weissenberg, E-mail: kw@mm.unknown

The effects of plantation characteristics on moose (Alces alces) browsing intensity was studied in 82 Scots pine (Pinus sylvestris L.) plantations in Southern Finland. Moose browsing occurred most commonly in plantations established on relatively fertile soil, and the degree of damage was at highest in plantations with openings. A high amount of brush, especially aspen, increased the risk of damage. Furthermore, damage was intensified in plantations situated on hills, slopes or at a long distance from main roads or settlements.

The PDF includes an abstract in Finnish.

• Heikkilä, E-mail: rh@mm.unknown

The size, nutrient contents and terpene composition of needles of Scots pine (Pinus sylvestris L.) saplings untouched and repeatedly browsed by the moose (Alces alces L.) were compared. Material was collected from a 14-years old and 2.5 m high pine stand in Bromarv, Southern Finland. The average length and fresh and dry weight of the needles were measured, and nutrient content (N, P, K, Ca, Mg, B, Cu) was determined.

The needles of repeatedly browsed pines became long and robust. There was, however, no difference between the dry matter percentage between the needles. The average nitrogen content was higher in the rebrowsed trees. Nitrogen content is, however, not directly correlated with the palatability of pine needles. Even phosphorus and boron content were higher in the damaged trees. No difference was found in Ca, K, Mg and Cu contents of the browsed and control pine saplings.

The PDF includes a summary in Finnish.

• Löyttyniemi, E-mail: kl@mm.unknown

The study was carried out at Padasjoki, Southern Finland, where moose (Alces alces L.) density on the winter range had been over 1.5 individuals/km². Moose browsing intensity, expressed in terms of number of twigs eaten and biomass used, increased with stand density (biomass). Total biomass consumption (dry weight) per sample plot and per sapling. The number of bites increased, but the percentage biomass removed did not differ when stand density increased. A relatively large bite size was observed on the plots of low stand density. The quantity of food, which on average was of relatively low quality, was obviously important due to the benefit gained through reducing the search time.

The nutritive value of the browse, expressed in terms of chemical compounds indicating low food digestibility, was lower in the dense than in the sparse Scots pine stand. However, the amount of crude protein and arginine were relatively high in the dense stand. We concluded that shading affected the nutritional status of saplings on high density plots.

Although the biomass removed by moose per sapling was high for low density plots, the remaining biomass was larger than that on the high-density plots owing to the relatively large twig biomass of saplings. The number of saplings per hectare without main stem breakage increased significantly as stand density increased.

The PDF includes a summary in Finnish.

• Heikkilä, E-mail: rh@mm.unknown
• Mikkonen, E-mail: tm@mm.unknown

The utilization of available food resources by the moose (Alces alces L.) was studied in a Scots pine (Pinus sylvestris L.) plantation containing an admixture of deciduous species. Rowan (Sorbus aucuparia L.) and aspen (Populus tremula L.) were highly utilized compared to pine and both silver birch (Betula pendula Roth) and downy birch (B. pubescens Ehrh.). However, they were not capable of withstanding continuous browsing by moose owing to their diminished biomass. In total, the browsing intensity (number of browsed twigs/tree) on pine and birch was about double of that on rowan and aspen.

The number of browsed twigs per tree increased as the amount of available main branches increased. The number of bites per available branch, as well as the maximum diameter of the bites, decreased as the density of the plantation increased. Silver birch was more used by moose than pubescent birch as well as planted silver birch compared with naturally regenerated trees.

Main stem breakage was especially common in winter 1988, the average height of the pine and birch trees being over two meters. The tops of broken stems were commonly utilized as food. The increase in moose density and the relatively deep snow cover evidently promoted the incidence of serious damage. The number of undamaged trees/ha was greater in dense than in sparse parts of the stand.

The PDF includes a summary in Finnish.

• Heikkilä, E-mail: rh@mm.unknown