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Climate & the Ecology of Turkey's Temperate Rain Forest

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Murgul Mountain

Dario Martin-Benito

Dario Martin-Benito

Tree Ring Laboratory

Columbia University

Neil Pederson

Neil Pederson

Tree Ring Laboratory

Columbia University

Nesibe Kose

Nesibe Kose

Faculty of Forestry

Istanbul University

Current News:
  • We will start the 2013 Field Season. Until then, we do not expect much news.

  • Some updates from the project will be found here. Our field excursion in these wonderful forests start with this post.

    Project Overview:

    The first step in this project, funded by the LDEO Climate Center, allows for the collection of ancient trees from the grand temperate rainforests of northeastern Turkey. Specifically, we aim to reconstruct historical drought dynamics using tree-ring proxies from broadleaf species in temperate rainforests of northeastern Turkey (NET). This region is home to a unique temperate rainforests that comprises some of the last patches of old-growth forest in Eurasia. Despite the existence of several tree ring width chronologies and dendroclimatic reconstructions for Turkey, paleoclimate records from NET area are scarce. This region of wet climate, surrounded by much drier and even desert lands, is poorly represented in previous reconstructions. These reconstructions are essential to investigate the potential impact of climate change on these areas of high biodiversity. Currently anthropogenic threats to these forests (e.g. logging, hydroelectric projects) make our collection urgent and timely relevant.

    logged old-growth trees

    Jengis (2nd from lft), Nesibe, and Dario in front of logs from old-growth trees. For scale, Dario is ~ 2 m tall. Photo: N. Pederson

    Once we have established a network of climatically-sensitive tree ring records in northeast Turkey, we will examine the past, present, and potential future trajectories of the Colchic forest within the study region using an independent network of tree ring reconstructions of forest history.


    Mountains along the southeastern coast of the Black Sea experience a pronounced lake effect, which together with orographic precipitation, cause a wetter climate (Fig 1) than surrounding areas. Precipitation can reach over 2000 mm/year in parts of NET and western Georgia. The temperate Colchic rainforest thrives in this region making it (1) one of the few temperate rainforests in the world and (2) the most important refugium of Tertiary flora and tree diversity in Western Eurasia (WEA) (DellaSala, 2011). These forests likely still hold the largest remnant of old growth forest with minimal human influence in WEA making it an ideal region for dendroecological studies of long-term forest dynamics.

    Geography of Turkish rainfall

    Figure 1 - Annual precipitation (mm/year) in Turkey. The study area, shown by triangle, is located within the wettest areas of Turkey.

    Although several dendroclimatic reconstructions of drought have been developed for several areas of Turkey (Akkemik et al., 2005; Touchan et al., 2005; Griggs et al., 2007; Akkemik et al., 2008; Kose et al., 2011), most have focused on the drier regions. In contrast, very little is known about the past climate in the more humid areas of NET because it is not well captured in existing reconstructions. Thus, it is crucial to reconstruct hydroclimatic conditions for this region. There is much potential for success as several species have shown a demonstrated potential for dendroclimatic reconstruction for 400 years or more [N. Kose, personal communication and Kose and Guner (2012)]. On a brief trip to the area in April 2012, we had the opportunity to sample trees in these temperate rainforests with Dr. Kose and identified two species with a great potential for reconstructing drought (Fig. 2).

    an old Quercus petrea

    Figure 2 - Dario with an old Quercus petrea - Photo: N. Pederson

    Forest Dynamics

    Although, temperate rainforests would seem more resilient to climate changes because of their wet and cool climates, drought has been a historical driver of forest structure in these areas (Kvavadze and Connor 2005) and some trees are very sensitive to drought (Kose and Guner 2012). Under climate warming and increased climatic fluctuations, moist regions could experience unprecedented rapid ecological changes (Booth et al. 2012). Long periods of drought might be more stronger drivers for compositional and structural changes than shorter and more intense ones (Hanson and Weltzin 2000). Our knowledge on how wet forest ecosystems respond to climate is limited to the range of climate conditions observed during the last 100-150 years, conditions which might be unique compared to those experienced in the past (Nicault et al. 2008; Trouet et al. 2009). We will implement an improved scale of research using dendrochronology to identify the relationship between disturbance and drought over centuries by investigating differential climate response of trees and long lasting effects of past droughts in forest structure and composition. These empirical results will eventually complement a forest succession modelling approach to examine possible ecological trends under global change. Understanding the past will contribute useful lessons on the response of these communities to a changing environment.

    Murgul Mountain Beech dominated forest

    The diverse temperate rainforest on Murgul Mountain where "Emir loves Tayla 1978" ;) - Photo: N. Pederson

    This project focuses on the Colchic rainforest of NE Turkey for three main reasons: i) it is one of the few temperate rainforests in the world and the most important refugium of Tertiary flora and tree diversity in Western Eurasia (WEA) (DellaSala 2011) providing a phylogenetically diverse set of species upon which to carry out our integrative ecological research; ii) it might be the largest remnant of old growth forest with minimal human influence in WEA, and thus ideal for dendroecological studies of long-term forest dynamics; and iii) it includes broadleaf and conifers species covering a wide range of tolerance and resistance to drought and shade leading to differential species-specfic responses to environmental changes.

    Sponsored by the LDEO CLimate Center.

    Updated: Dec '12