Content area
Full text
Eur J Forest Res (2015) 134:7587 DOI 10.1007/s10342-014-0834-2
ORIGINAL PAPER
Browsing regime and growth response of Abies alba saplings planted along light gradients
Andrea D. Kupferschmid Ulrich Wasem
Harald Bugmann
Received: 2 September 2013 / Revised: 24 June 2014 / Accepted: 28 July 2014 / Published online: 18 August 2014 Springer-Verlag Berlin Heidelberg 2014
Abstract Silver r is a highly desirable species in European mountain forests from a management and conservation point of view, but it is also highly palatable for ungulates. We planted Abies alba saplings along natural light gradients to explore under natural browsing: (1) the light conditions under which saplings grow best in the absence of browsing; (2) when and by which ungulate species which saplings are browsed; and (3) under which conditions saplings react most vigorously to browsing. The experiment was carried out in a Swiss forest using four fenced plots each containing about 30 saplings planted in 2001, which were between 17 and 100 cm tall in 2009. For half of the saplings, browsing was allowed and lmed from April 2009 to January 2010. Saplings grew better with more light (13 % rather than 10 % canopy openness). Browsing was not a single event per sapling but a continuous process during the winter months. Almost all saplings exposed to browsing suffered heavy browsing by chamois and red deer, but no roe deer browsing was observed. The remainder of the browsed shoots were longer and contained more buds under 13 % canopy openness. The browsing-induced height differences between browsed and
unbrowsed trees increased over time under all light conditions, and almost no diameter growth was measured in the years after browsing. In cases with severe browsing, management aimed at letting in more light does not lead to a substantially better tolerance of browsing. We thus recommend integrating the feeding strength in the assessment of browsing.
Keywords Ungulate browsing Herbivory Silver r
Natural regeneration Canopy openness
Introduction
Browsing by ungulates such as deer and chamois is one of many biotic factors that affect tree establishment, growth and mortality. Tree saplings are part of the normal food of ungulate species such as red deer (Cervus elaphus L.), roe deer (Capreolus capreolus L.) and chamois (Rupicapra rupicapra L.) (cf. Gebert and Verheyden-Tixier 2001; Tixier...