The ever growing presence of red deer (
Cervus elaphus) in the forest perimeters of the Lous? Mountain area of central Portugal is causing local conflicts among stakeholders who report
damage to agriculture
and forest. One of the forest perimeter regions (Lous?) has been selected to develop a Portuguese St
andard for the Forest Certification System (PEFCC). The aim of this study was to determine whether any real
damage or impact caused by red deer had in fact occurred in the area. Four types of forest cover were considered
and nine plots (150 m
2) were r
andomly selected within each type. All trees were recorded
and the diameter at breast height (dbh) was measured. The characteristics of marks of each rubbed tree were recorded. The amount of foliage
browsing was estimated visually as a percentage except in situations of regeneration where the total number of consumed leader or lateral shoots was counted. The shrub layer was scored according to height
and cover. Altitude
and distance to the nearest village, river or national road were measured in each plot to analyse their influence on the degree of
damage. Cluster analysis allowed us to observe a
damage pattern across the study plots that separated
browsing damage from
fraying damage. Pine regeneration type vegetation suffered significant
damage by
browsing but the percentage of
damage due to
fraying was not significantly different between forest types. Some species of trees, such as sweet chestnut (
Castanea sativa), were more susceptible to
fraying damage. In all cases, deer clearly preferred rubbing on the smallest trees.
A classification tree where the percentage of rubbed trees was the response variable, showed that diameter at breast height (dbh), distance to national road and the number of trees were primary contributors to probability of damage. We propose that new indicators should be introduced into the certification process and that there is also a need to find a balance between different stakeholders?interests and wildlife.