Recent growth trends of black pine (Pinus nigra JF Arnold) in the eastern mediterranean

Abstract

Past and present environmental changes cause significant changes in tree growth in many parts of the world, where both decreasing and increasing growth trends have been detected over the last decades. The Mediterranean basin is especially sensitive to climate change and subsequent tree growth declines. In this article, we present the first study on recent tree growth trends in Turkey. Pinus nigra is a drought-sensitive species and one of the most common and economically important native conifers to Turkey. Tree-ring cores were taken from 61 Pinus nigra plots spread over the entire Lakes District (Southwest Turkey), near the species' southern range limit. The samples cover the 1839-2013 time period. We apply the Regional Curve Standardization technique and statistical modeling to the tree ring width data to investigate long-term growth trends. Both methods show remarkably similar results: a slowly increasing growth trend until the 1970s, followed by a decreasing trend. This recent negative trend is highly correlated with increased temperature and drought in summer, which suggests that it is likely caused by climate change.