baumzaehlen - Primeval Forests & Their Trees

Alborz Mountains , Iran

There are at least 1000 km ² of untouched primary forests (in 2005) on the moist northern slopes of the Alborz Mountains ¹ . Precipitation is fairly high, over 2000 mm/year in the west decreasing towards the east ² .

The whole northern Alborz region has 65–90 tree species depending on the source and the definition of tree ^{1 2 3} . The most important trees on the lower slopes are Quercus castaneifolia (chestnut-leaved oak), Carpinus betulus (European hornbeam) and Parrotia persica (Persian ironwood). The next zone is often shrouded by fog and dominated by Fagus orientalis (oriental beech). The uppermost zone (to the tree line at 2500–3000 m) is drier, annual precipitation being only 400–600 mm with a 4 months dry period; it is dominated by low Quercus macranthera (Caucasian oak) and Carpinus orientalis (oriental hornbeam). Traditionally cattle graze the dry and cool upper ridges in spring and summer, and are taken down to the coast for autumn and winter; consequently, the forests in the moist and often steep-sloped Fagus zone are those best preserved. ²

The forests of northern Iran and western Georgia (see Mtirala National Park ) have a number of common features ⁴ , but western Georgia’s dense evergreen shrubby understorey is missing. Lianas are also prominent in Northern Iran. Thickets of thorny shrubs grow in openings.

The dry southern slopes of the Alborz Mountains were originally covered by Juniperus excelsa subsp. polycarpos (Persian juniper) woodland but it has mostly been cleared ⁵ .

References:

1 Knapp. H. D. (2005): Die globale Bedeutung der Kaspischen Wälder. In Nosrati, K et al. (eds.): Schutz der Biologischen Vielfalt und integriertes Management der Kaspischen Wälder (Nordiran) . Bundesamt für Naturschutz.

2 Sagheb Talebi, K., Sajedi, T. & Pourhashemi, M. (2014): Forests of Iran. Springer.

3 Seifollahian, M., Rastaghi, M. E. & Hedayati, M.-A. (2005): Die Bedeutung der Pflanzenarten der Kaspischen Wälder. In Nosrati, K et al. (eds.): Schutz der Biologischen Vielfalt und integriertes Management der Kaspischen Wälder (Nordiran) . Bundesamt für Naturschutz.

4 Nakhutsrishvili, G. (2013): The Vegetation of Georgia (South Caucasus). Springer.

5 Bobek, H. (1951): Die natürlichen Wälder und Gehölzfluren Irāns. Geographisches Institut Universität Bonn.