Pollen analysis of the peat in a small mire on the northern slope of the Alborz Mountains (550 m a.s.l.) in the Central Caspian forests of Iran reveals changes in forest and wetland vegetation during the last millennium. A forest, principally of Alnus and Carpinus occurred over almost the whole period. Quercus, Ulmus and Parrotia were less common, while Fagus, Pterocarya, Acer and Diospyros fluctuated as a probable result of human interference and/or climatic change. Two phases of clay deposition in the mire can be dated to the `Mediaeval Climatic Anomaly' (AD 1100) and the beginning of the `Little Ice Age' (AD 1560—1600). Although human activity seems to have persisted in the region during the whole of the past millennium, increased NAP values point to intensified human interference since the beginning of the nineteenth century.
Coarse woody debris (CWD) is an important structural and functional component in forests in Northern Iran. In this study we determine the temporal patterns of CWD in Kheyroud Forests by examining the CWD volume in different decay classes and size classes along a chronosequence of secondary forest succession. The volume of CWD followed the general “U-shaped” temporal trend: the highest in the late successional forest (51.25 m<sup>3</sup>.ha<sup>–1</sup>), lowest in the middle successional forest (25.95 m<sup>3</sup>.ha<sup>–1</sup>) and intermediate in the early successional forest (37.05 m<sup>3</sup>.ha<sup>–1</sup>). The late successional forest had a larger amount of logs, snags and stumps than the other two forests. In contrast, the snag volume did not differ between the late and middle successional forest. CWD in decay classes III and V was greater in the late successional forest than that in the other two forests, while CWD in decay classes II and I did not differ among the three successional forests. CWD in class II and I was significantly higher in the early successional forest than that in the middle successional forest. In the early and middle successional forests, CWD in early decay class was dominated by <I>Carpinus betulus</I> L. followed by <I>Fagus orientalis</I> Lipsky. In the late successional forest, CWD in early decay class was dominated by <I>Fagus orientalis</I> while CWD in the late decay class was dominated by <I>Carpinus betulus</I>. While forest succession had a large influence on the amount of CWD in different decay classes, it had no effect on CWD distribution among the different size classes. Our results suggest that both anthropogenic and natural disturbances have had a long-term effect on the distribution of CWD among three forests.
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