Consequences of increased deer browsing winter on silver fir and spruce regeneration in the Southern Vosges mountains: Implications for forest management

Abstract

-Forest and wildlife management practices in the Vosges have changed rapidly during the last 200 years, modifying interactions between animals and plants, especially deer and silver fir. In order to assess the impact of browsing on fir regeneration, we compared two sets of similar forests which differed primarily in terms of deer population dynamics and history. On slopes with southern exposures, many fir seedlings did not reach heights above 30 cm and spruce developed; this was related to browsing intensity. Spruce expansion was also facilitated by its presence in nearby mature stands, and was not related to a particularly high level of browsing. Of the six site characteristics taken into consideration, only the presence of foliage from the understorey above seedlings was found to benefit fir by limiting spruce development and reducing browsing intensity. Results are discussed in light of current and proposed management practices for silver fir-beech forests and their wildlife.silver fir-beech forest / regeneration / browsing / deer / management Résumé -Conséquences de l'augmentation de l'abroutissement hivernal par les cerfs et chevreuils sur la régénération du sapin et de l'épicéa dans les Vosges du Sud. Implications pour la gestion forestière. Les récents changements de gestion forestière et faunistique ont profondément modifié les interactions entre la flore et la faune, notamment entre les cervidés et le sapin. Pour évaluer l'impact de l'abroutissement sur la régénération du sapin, nous avons comparé deux ensembles de forêts sur la base de conditions environnementales similaires mais à différents degrés de colonisation par les cervidés. Les résultats montrent que les sapins des versants exposés sud subissent une pression d'abroutissement forte et poussent difficilement au-delà de 30 cm, alors que l'épicéa est particulièrement abondant. L'expansion de l'épicéa au détriment du sapin abrouti est également facilitée par sa présence parmi les arbres matures, mais ici sans relation avec un abroutissement particulièrement fort du sapin. Un seul facteur parmi les sept étudiés joue en faveur du sapin : la présence d'une strate arbustive, qui limite le développement de l'épicéa et réduit l'abroutissement du sapin. Les résultats sont discutés en relation avec la gestion actuelle des hêtraie-sapinières vosgiennes et de leur faune, et des propositions sont émises pour une gestion qui intègre davantage la présence des animaux.hêtraie-sapinière / régénération / abroutissement / cervidés / gestion

Effects of resource availability on condensed tannins and nitrogen in two Quercus species differing in leaf life span

“…Different studies have outlined the importance of environmental conditions to finally determine herbivory intensity [25,46]. Although we did not find effects of fertilization treatments besides leaf N, it is likely that perturbations that modify nutrient availability, such as forest fires, can potentially modify leaf chemistry and affect herbivore performance.…”

Influence of agricultural crops adjacent to forest on woody species browsing: Is it advantageous to have a tasty neighbour?

“…Very similar results of the impact of winter on large herbivores were reported in studies by Christianson and Creel (2007). In winter, the animals face a shortage of good-quality food and increased energy expenditure for thermoregulation and movement (Moen 1973;Parker et al 1996) and so they intensively exploit the shoots of woody species as the most attractive and often the only source of their food (Gill 1992;Heuze et al 2005;Hodder et al 2013). The winter supply of green cereal crops on agricultural lands was of higher quality than tree shoots in the forest environment but its quantity was too small to constitute a more significant component of large herbivore diet.…”

Ungulate Impact on Natural Regeneration in Spruce-Beech-Fir Stands in Černý důl Nature Reserve in the Orlické Hory Mountains, Case Study from Central Sudetes

“…Ungulates can be the most important driver of meta-community structure in mesic systems without strong abiotic influences in warm temperate forests [28]. An analysis of the global level of browsing revealed that seedlings on south-facing slopes were browsed more intensively than those on slopes with other exposures [29]. Similarly, Cagnacci et al [30] showed that probability of roe deer (Capreolus capreolus L.) presence decreased nonlinearly with elevation because the thicker snow cover and lower temperatures in spring reduced ungulate movement and the duration of the period when seedlings are available.…”