Climate signals in the ring widths and stable carbon, hydrogen and oxygen isotopic composition of Larix decidua growing at the forest limit in the southeastern European Alps

Abstract

The southeastern border of the European Alps is not well resourced with high-resolution climate proxies and experiences a distinct climatic regime from the northern and western Alpine zones. Here, we present new high-resolution climatic proxies (AD 1907(AD -2006 from ring widths and stable carbon (d 13 C), non-exchangeable hydrogen (d 2 H) and oxygen (d 18 O) isotope ratios of cellulose extracted from Larix decidua tree rings, growing at the forest limit in the southeastern European Alps (Slovenia). d 13 C, d 2 H and d 18 O are strongly (p \ 0.001) and positively correlated with each other. June temperature has the strongest control on tree ring width (TRW), while later summer conditions (JulyAugust) influence the stable isotope composition. All four proxies are strongly correlated (r [ 0.4; p \ 0.001) with summer temperature and also sunshine hours, while precipitation has less impact. A combination of TRW and d 13 C provides the greatest potential for reconstructing past temperatures (June-August) with significant (p \ 0.001) correlations with gridded temperatures extending across a very large part of southern and western Europe west of the Carpathian Mountains. The water isotopes (oxygen and hydrogen) record conditions in the Adriatic and Mediterranean, which are the source area for the air masses that bring precipitation to this region giving strong correlations with temperatures in southern Italy and the western part of the Balkan Peninsula. Combining proxies with different spatial and temporal signals allows the strength and spatial footprint of climate signals to be enhanced. These findings open new perspectives for climate reconstruction in the southeastern European Alps and Western Balkans.

Simultaneous Determination of Stable Carbon, Oxygen, and Hydrogen Isotopes in Cellulose

“…This material was prepared from an absolutely dated tree ring series and had previously been analyzed (single measurements) by standard methods (combustion (δ 13 C), pyrolysis (δ 18 O), and nitration with combustion (δ 2 H)). 21 Figure 1 confirms the efficacy of the triple-isotope approach and the capability of the system to reproduce results generated using conventional methods. Common interannual trends were preserved throughout the series, with mean annual precision calculated from triplicate measurement of each of the 50 rings analyzed, well within acceptable limits (±0.07‰ δ 13 C, ± 0.20‰ δ 18 O, and ±1.28‰ δ 2 H).…”

Long-term summer sunshine/moisture stress reconstruction from tree-ring widths from Bosnia and Herzegovina

“…We used the term "lesssunny" to denote years with an unusually (below 1 or 2 SD) low number of mean June-July sunshine hours. Because the solar radiation can be reduced not only by the cloud cover (Suehrcke, 2000;Arking et al, 1996), but also by other factors, such as volcano eruptions (Handler, 1989), forest fires (Chubarova et al, 2008) and other aerosols (Satheesh and Krishna Moorthy, 2005;Moosmüller et al, 2009), we decided that the term less-sunny is the most appropriate.…”

“…However, despite the numerous dendrochronological investigations across the Balkan Peninsula, climate reconstructions in the north-western part of Balkan Peninsula are still not available. Current dendrochronological investigations in developing TRW and maximum density chronologies from across the Balkan Peninsula -Slovenia (Hafner et al, 2011), Croatia, BiH , and Montenegro (T. Levanič, personal communication, 2012), as well as Albania (Seim et al, 2012;Levanič and Toromani, 2010), Bulgaria Panayotov et al, 2010) and Romania , should soon yield results that enhance our knowledge of past variation and contribute to dendroclimatological network of Balkan Peninsula (Luterbacher et al, 2012).…”

Leaf habit of Late PermianGlossopteristrees from high-palaeolatitude forests

“…The southernmost part of Gondwana was interpreted to be a tundra ecosystem by Rees et al (2002), but modelled temperature using a dynamic ocean-atmosphere model produces conditions more favourable for forest growth (kiehl & Shields 2005;Roscher et al 2011). Ohashi et al 2009;Offermann et al 2011;Roden & Farquhar 2012), and to complement dendrochronology-based dendroclimatology studies (Wilson & Grinstead 1977;Schleser et al 1999;Poussart et al 2004;Treydte et al 2006;Hafner et al 2011;Au & Tardif 2012). Only in the last decade, however, have high-resolution (more than three measurements per ring) isotope analyses been completed on single growth rings in modern trees (e.g.…”

“…We interpret that erosion and fire were important disturbance processes. Erosive processes in extant boreal forests produce trends in forest structure and composition away from the margin of rivers and onto more stable floodplain environments (Gregory et al 1991;He & Duncan 2000). Comparing the sites, Graphite Peak and Wahl Glacier are proximal to the fluvial systems whereas Mt.…”