Coarse woody debris variability due to human accessibility to forest

Originally published in Forests (MDPI): Behjou FK, Lo Monaco A*, Tavankar F, Venanzi R, Nikooy M, Picchio R (2018) Coarse woody debris variability as result of human accessibility to forest. Forests 9(9): article number 509 (open access) Corresponding author: Angela Lo Monaco, [email protected] DOI: 10.3390/f9090509 The article can be dowloaded at: https://www.mdpi.com/1999-4907/9/9/509 Abstract: Coarse woody debris (CWD) plays an important role in supporting biodiversity and assisting ecological processes. Sometimes local people intervene modifying the expected distribution of CWD components, harvested as fuel wood. The effect of the human accessibility (HA) on the volume and characteristics of CWD (snag, downed log and stump) was investigated in the natural uneven-age mixed hardwood stands of the Hyrcanian forests of Iran to quantify the impact on CWD. The HA was classified into three classes (easy, medium and difficult) on the basis of slope class, slope direction to the nearest road and road type. As expected, a negative relationship between the degree of accessibility was found with respect to the main qualitative and quantitative indices referring to CWD. The results showed that the volume of CWD decreased with an increase in human accessibility class (HAC), thus the mean volume of CWD in the difficult, medium and easy accessibility classes were 14.87 m3 ha1, 8.84 m3 ha1 and 4.03 m3 ha1, respectively. The decrease in CWD volume was more associated with the decreasing volume of small diameter of low decayed downed logs. The ratio of snag volume to standing volume, the ratio of downed log volume to the volume of trees and the ratio of CWD volume to standing volume increased with a decrease in HAC, while the ratio of downed log volume to snag volume decreased with a decrease in HAC. No selective behaviour on the botanical species of CWD was recorded. For ecological forest management, the effect of HAC on CWD should be considered. A constant supply of snags and downed logs must be preserved to assure a high level of biodiversity. To balance social needs and biodiversity requirements, an increased level of CWD retention might be needed in areas with easy accessibility. The obtained results may be useful when ecological and socio-economical needs have to be taken into consideration in future policy-making decisions. Keywords: snag; downed log; stump; forest road; uneven-agemixed hardwood stands; Hyrcanian forest

Effect of logging wounds on diameter growth of beech (Fagus orientalis Lipsky) trees following selection cutting in Caspian forests of Iran

Background Logging damage to residual trees during selection cutting may lead to serious economic losses in terms of both timber quality and diameter growth reduction. In this study, we investigated the effect of logging operations on residual tree damage and the consequence of injuries on diameter growth in an uneven-aged mixed forest dominated by beech (Fagus orientalis Lipsky)

The Effect of Selection Cutting on Frequency and Characteristics of Thick Trees (Normal, Rotten, Dead Trees) in Asalem-Nav Forest

Rotten and dead trees are the main component of forest ecosystems and play an important role in maintaining forest biodiversity. In this research frequency and characteristics of large diameter trees (normal, rotten, and dead trees) with diameter at breast height greater than 60 cm were studied in two compartments (selective logged and protected) in Asalem-Nav forest. Random systematic sampling method with grid of 100 &times; 100 m and plot area of 0.2 ha was used for data collection. The results showed frequency and volume of large diameter trees of all three groups in the logged parcel were lower than protected parcel (P < 0.01). The height of rotten trees and dead trees in the protected compartment were greater than logged compartment (P < 0.01). Thick trees of all three groups in the protected compartment were compounded from more species than logged compartment as well. Cavities created by forest birds on the bole of rotten trees and dead trees have more frequency in the protected compartment than the logged compartment. This research indicated that protection of rotten trees, dead trees and remaining thicker trees from different species have special importance for protection of natural structure and biodiversity of forest stands