Spatial Distribution and Volume of Dead Wood in Unmanaged Caspian Beech (Fagus orientalis) Forests from Northern Iran

Abstract

Unmanaged forests are remnants of natural ecosystems that provide a basis for close-to-nature silvicultural research and applications. These forests have high amounts of dead wood, and although this material is being increasingly studied, the diversity of dead wood in terms of different diameters, decay stages, and spatial distribution patterns is as important as its volume for understanding forest dynamics. Here, we study natural forests in northern Iran to investigate the spatial distribution, decay stages, and volume of dead wood in unmanaged temperate forests at different developmental stages. Three stem-mapped sampling plots (100 m × 100 m) were established in uneven-aged stands dominated by Caspian beech (Fagus orientalis Lispsky). The total dead wood ranged from 37 to 119 m 2 ha −1 . Our results imply a spatial distribution shift from aggregation to OPEN ACCESSForests 2013, 4 752 randomness for dead trees in Caspian beech forest succession. We detected significant spatial interactions (attraction) between living and dead trees at short to medium spatial scales (1-20 m) in the plot with the earlier successional stage, suggesting that intra-specific competition is a prevailing force causing tree mortality at the stem-exclusion phase. By contrast, as trees become dominant with the mortality of other trees, the random tree-mortality pattern prevails. The spatial distribution and volume of dead wood may serve as a management target in near-to-natural Caspian beech forest. On the basis of our results, conservation-oriented management strategies should take into account the increasing amount of dead wood, particularly of large diameter in a late stage of decay.

Effect of topography on tree species composition and volume of coarse woody debris in an Oriental beech (Fagus orientalis Lipsky) old growth forests, northern Iran

“…In this study we found a mean CWD volume of 74.6 ± 18.1 m 3 ha -1 with a range of 1.2-136.1 m 3 ha -1 , similar to several other studies carried out in the Iranian beech forests (Sefidi et al 2013, Amanzadeh et al 2013, Sefidi & Marvie-Mohadjer 2010. Contrastingly, the total volume of dead timber at the Milesice Forest Reserve in the Czech Republic reached 324 m 3 ha -1 (Vrska et al 2001), that was higher than our findings.…”

“…The same authors found a greater CWD volume on more fertile north-facing slopes than on south-facing slopes. Moreover, in the north of Iran Alidadi et al (2015) showed dead wood decomposition rates of F. orientalis and Carpinus betulus significantly different between north facing and south facing slopes (Alidadi 2013). In this study, slope aspect was not significantly correlated with CWD volume or density, despite an accumulation of CWD in north-facing slopes was expected.…”

“…The same authors also showed that different ecological conditions can affect decomposition rates and dynamics of woody debris as well as accumulation of CWD. Furthermore, Alidadi (2013) reported that the decomposition of oriental beech CWD largely differs from that reported for European beech, as tree dimensions affect the dead wood pool within stands. Indeed, long-lived oriental beech trees can reach more than 2 meters in diameter at productive sites, and show a high amount of forest dead wood in the studied sites (Sefidi & Etemad 2012, Moradi et al 2012.…”

Structure and Spatial Distribution of Dead Wood in Two Temperate Old-Growth Mixed European Beech Forests

“…Oheimb et al (2007) found the same pattern in a temperate near-natural beech forest in Germany; in an 8-ha sample plot, the overall spatial distribution of dead trees exhibited a random pattern, whereas uprooted beech trees deviated from random to an aggregated pattern. In unmanaged Caspian beech forests in Iran, Amanzadeh et al (2013) observed a random spatial pattern of dead trees in two plots and detected significant spatial aggregation in only one plot, a plot governed by high density-dependent competition (selfthinning). Conversely, a significant aggregated pattern of standing and fallen dead trees was detected in Albanian virgin beech forests according to Meyer et al (2003).…”

“…Although old-growth forests may serve as a reference for managed forests, providing important information for conservation and promoting biodiversity, few studies have examined quantity and quality (dead wood types, decay classes), size class distribution and spatial patterns of dead trees in natural forests (Oheimb et al, 2007;Rahman et al, 2008;Amanzadeh et al, 2013), mainly due to the scarcity and inaccessibility of remnant virgin forests. In particular, this applies to remnant natural beech forests in Southeastern Europe.…”