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, lomonaco@unitus.it

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 ha􀀀1, 8.84 m3 ha􀀀1 and 4.03 m3 ha􀀀1, 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 forests