Mehrstufige Verjüngungskontrollen und Grenzwerte für die Verbissintensität | Comparitive regeneration control and limiting value of browsing damage intensity

Abstract

Storms such as Lothar often bring to light what has previously lain hidden in dark forests, thereby heightening our perception of problems in the realms of forest and game. Hunting and forestry measures can solve these problems and basic information is important in order to determine suitable measures. This is why regeneration control is called for after every storm to gather up-to-date information on forest regeneration and the influence of game. A collecting concept must include a supply of data from many levels. In a first step, on the basis of a survey assessment, we ask whether the region under investigation is a problem area or not and regions are accordingly assigned to one of either category. In a second step, measurements are carried out on samples in chosen indicator areas. These indicator areas are between 30 and 50 ha and representative of the forest and game conditions of the whole. In this phase woodland plants are inventoried according to the vegetation period of the previous year and the dormant phase directly preceding the time of the survey in spring according to tree species, size and damage to crown shoots. In a third step, silvicultural reference plots of around 0.5-1.0 ha serve to evaluate the undertaken measures and to compare the silvicultural goals on the stand level. Silvicultural evaluation is best carried out for the proportion of tree species in increment and growth stages, as well as for the distribution of tree species over sylvicultural reference plots,although not for the number of stems, as fluctuation is high in natural regeneration.

Initial Survival and Development of Planted European Beech (Fagus sylvatica L.) and Small-Leaved Lime (Tilia cordata Mill.) Seedlings Competing with Black Cherry (Prunus serotina Ehrh.)

“…The finding that more seedlings died outside the fence (Figure 1) can be explained by grazing mammals, whose browsing on seedlings commonly result in the loss of the leader shoot [32]. This loss is closely correlated to seedling mortality if approximately one third of the shoot length is browsed [33]. In the present study seedlings were sometimes browsed down to ground level or were partly missing.…”

Determining Statistically Robust Changes in Ungulate Browsing Pressure as a Basis for Adaptive Wildlife Management

“…Since quantifying browsing marks of ungulates on forest regeneration is more efficient than counting free ranging animals, and provides a higher information value of the ungulate impact on vegetation, this method is commonly used to assess ungulate browsing in forestry studies [6,[51][52][53][54]. However, the correct method to measure ungulate impact is still under debate (e.g., [26,53,[55][56][57]). While local scattered measurements such as wildlife enclosures are often used [8,53], periodic and systematic large-scale regeneration inventories are still rare due to their time-intensive and costly nature [6,52,58,59].…”

“…Regularly conducted browsing inventories serve as a monitoring and planning tool for adaptive wildlife management. Browsing impact is usually depicted by using a relative scale (e.g., [22,56]), such as the browsing percentage or intensity. Browsing intensity describes the relation of seedlings that have been browsed on their leader shoot to the total observations [23].…”

Ergebnisse aus Untersuchungen zum Wildtiereinfluss auf die Waldverjüngung in der Schweiz | Results of various studies on the influence of wildlife on forest regeneration in Switzerland

“…Der Aufwand kann aber erheblich reduziert werden, wenn die Stichproben auf eine relativ kleine, den Wildraum repräsentierende Teilfläche, die soge nannte Indikatorfläche, konzentriert werden. Eine Indikatorfläche hat eine Ausdehnung von 30 ha und umfasst 30 Stichproben (Rüegg & Nigg 2003). Gut belegte Gebiete weisen pro 500 ha Wald eine Indi katorfläche aus.…”