Clear-cuttings effect in ecological restoration of the Norway spruce stands damaged by red deer

Eurasscience Journals Eurasian Journal of Forest Science (2018) 6(1): 23-34 Clear-cuttings effect in ecological restoration of the Norway spruce stands damaged by red deer (Cervus elaphus) Radu Vlad1, Cristian Gheorghe Sidor*1 1) National Institute of Research-Development in Forestry "Marin Drăcea", Câmpulung Moldovenesc Station, Calea Bucovinei 73 bis, 725100, Câmpulung Moldovenesc, Suceava, România *corresponding author: Tel: +40230314747; Fax: +40230314746; E-mail: Abstract In the recent decades, in Norway spruce forests have been reported ecological imbalances caused by red deer (Cervus elaphus) by bark-stripping, with a great impact on stability and productivity of the stand. When the profitability of the Norway spruce stands starts to decrease, due to the wood volume with stem decay, an ecological restoration of this ecosystems is imposed. This study reports a case study from the north of Eastern Carpathians. It presents the results of nine experiments from two of the most affected area from North of Romania by red deer (Cervus elaphus), in order to test the success of applying some forestry treatments: the progressive clear-strip cutting (stands more than 10 ha) and the clear cutting on small areas (stand less than 10 ha), with reference to strip width, the direction of the strips, the felling direction, the regeneration process and the cuts return interval. Number of extracted trees∙ha-1 varied between 1340 and 324 and the removed volume was between 457 m3∙ha-1 and 181 m3∙ha-1. The proportion of stem decay volume was important (between 23% and 42%), being related to the stand age. In stands over 50 years, the wood volume with stem decay is less than 30% (23% to 27%), while in those over 35(40) years, it is greater than 33% (34% to 42%). A successful regeneration (natural and artificial), in the time elapsed from the implementation of the previous silvicultural treatments (about 25 years), support the success of the applied ecological restoration. The progressive clear-strip cutting and clear cuttings on small areas, as part of the ecological restoration of the red deer (Cervus elaphus) damaged Norway spruce stands, showed good results, and could be considered as a tool for the ecological restoration of these stands. Keywords: forest management, Picea abies, forestry treatments, stem decay Özet Son yirmi otuz yıldır, Norveç Ladini ormanlarında kırmızı geyiklerin (Cervus elaphus) kabuk soyma faliyeti sonucu, meşcerelerde büyüme ve dayanıklılıkları konusunda ciddi zararlar olduğu belirtilmiştir. Norveç Ladini ormanlarındaki kârlılık odun hacmi ve gövde çürüklüğü nedeniyle azaldığında, bu ekosistemlerde bir yenileme çalışması yapılması gerekliliği doğmaktadır. Bu çalışma, kuzeydoğu Karpatlar’daki ormanlarda yapılan bir araştırmayı sunmaktadır. Çalışma, Romanya’nın kuzeyinde kırmızı geyiklerin en yoğun zarar yaptığı 9 alandan 2’sinde yürütülmüş ve bazı ormancılık uygulamalarının, bu zararlara karşı elde edebildiği başarıyı sunmaya çalışmak için; kademeli etek şeridi tıraşlama (10 ha’dan büyük alanlarda), tam alanda tıraşlama (10 ha’dan küçük alanlarda) uygulanmış ve şerit genişliği, şerit yönü, devirme yönü, gençleştirme işlemi ve makta süresi faktörleri bağımsız değişken sınıfları olarak uygulanmıştır. Kesilen ve meşcere dışına çıkarılan ağaç sayısı 324 ile 1340 adet/ha ve kabuklu odun hacmi 181 ile 457 m3/ha arasında değişmiştir. Gövde çürüklüğü oranı da (%23 ile 42 arasında) yaşa bağlı olarak, önemli düzeyde yüksek bulunmuştur. Yaşı 50’den yüksek olan meşcerelerde gövde çürüklüğü %30’dan düşük (%23 ve 27), yaşı 35’ten büyük meşcerelerde (40 yaşındaki) 23 Eurasian Journal of Forest Science 6(1):23-34 (2018) %33’ten büyük (%34 ve 42) olduğu tespit edilmiştir. Bir önceki silvikültürel işlemin uygulanmasından itibaren yaklaşık 25 yıllık sürenin geçmesinin tamamlanmasının ardından gerçekleştirilen başarılı gençleştirme uygulamasının ekosistemin yenilenmesine iyi bir şekilde hizmet ettiği görülmüştür. Kademeli etek şeridi tıraşlama ve küçük alanlarda tıraşlama kesimi yapılması, kırmızı geyikler tarafından tahrip edilen alanların ıslâhında etkili olduğu tespit edilmiş ve bu tür alanların iyileştirilmesinde başarılı bir uygulama olarak seçilmesi önerilmektedir. Anahtar kelimeler: Orman yönetimi, Picea abies, ormancılık uygulamaları, gövde çürüklüğü. Introduction The future development of forestry needs improvements of the management (Schlaepfer 1987, Hasle et al. 2000) and, among others, attention should be pay on the possible actions of disturbing factors (e.g. wind, snow and deer) in some risk areas (deCalesta and Stout 1997, Akashi, 2009, Hlásny et al. 2011, Niinimäki et al. 2012). This is also the case of Norway spruce stands affected by red deer (Cervus elaphus), where in some cases the human intervention is necessary, in order to link the structure of the affected stands with the site potential and the ecosystem functions assigned (Jackson and Hobbs 2009). To promote a sustainable management of these stands, an appropriate framework should be considered (Ballon et al. 2005, Slodicak and Novak 2006, Vospernik, 2006, Kiffner et al. 2008), including key aspects as biodiversity or the multiple ecological and social-economic functions of these forest ecosystems (Kishimoto et al. 2010, Żmihorski and Durska 2010, Gheysen et al. 2011). In young Norway spruce stands, most of the red deer (Cervus elaphus) damaged trees belong to the upper canopy classes and, thus, the mid- and long-term management of these stands is affected (Welch et al. 1987, 1988, Verheyden et al., 2006, Gheysen et al. 2011). Many factors (stand age and composition, damage frequency and wound age and their location in the stand) must be accounted in their management, among which the costs of the wounds produced by red deer (Cervus elaphus) in forests (Ward et al. 2004). Past research (Vasiliauskas and Stenlid 1998, Welch and Scott 2001, 2008, Gill et al. 2001) emphasized the prejudices of the timber volume, by a qualitative downgrade of stem decay, as resulted from red deer (Cervus elaphus) wounds (Čermák et al. 2004, Čermák and Strejček 2007, Scott et al. 2009, Vasaitis et al. 2012). In Romania, the red deer population (Cervus elaphus) has grown significantly after the Second World War, when large gaps were created in the stands by clear-cutting on large areas or following extensive windfalls (Ichim 1990). As a result, in the Norway spruce forests located in the north of Eastern Carpathians important damages produced by the red deer (Cervus elaphus) were recorded. For example, in Suceava County, the affected stands represent about 21.3% of forest area; most affected being the Norway spruce stands between 20 and 80 years old (Vlad and Sidor 2011). The structure, function and dynamics of natural and artificial systems (Norway spruce stands, in our case) are affected when the systems are subjected to severe stress (damages produced by deer) and that can be considered, besides a major environmental (...truncated)