The long-term relationship between temperature and hydroclimate has remained uncertain due to the short length of instrumental measurements and inconsistent results from climate model simulations. This lack of understanding is particularly critical with regard to projected drought and flood risks. Here we assess warm-season co-variability patterns between temperature and hydroclimate over Europe back to 850 CE using instrumental measurements, tree-ring based reconstructions, and climate model simulations. We find that the temperature–hydroclimate relationship in both the instrumental and reconstructed data turns more positive at lower frequencies, but less so in model simulations, with a dipole emerging between positive (warm and wet) and negative (warm and dry) associations in northern and southern Europe, respectively. Compared to instrumental data, models reveal a more negative co-variability across all timescales, while reconstructions exhibit a more positive co-variability. Despite the observed differences in the temperature–hydroclimate co-variability patterns in instrumental, reconstructed and model simulated data, we find that all data types share relatively similar phase-relationships between temperature and hydroclimate, indicating the common influence of external forcing. The co-variability between temperature and soil moisture in the model simulations is overestimated, implying a possible overestimation of temperature-driven future drought risks.

Variations in the tree line position and glacier activity in the Central and Eastern Altai regions in the Holocene were reconstructed on the basis of analysis of sixty radiocarbon and eighteen dendrochronological dates. The tree line was higher than now in the Early and Middle Holocene, and the climate was warmer and, likely, more humid. Glaciers advanced in the forests 300, 1400, and 3000–6000 years ago. In the last millennium the forest decline at the upper tree limit occurred in 1206–1256, 1445–1501, and 1642–1736.

PICEA SCHRENKIANA RING WIDTH AND DENSITY AT THE UPPER AND LOWER TREE LIMITS IN THE TIEN SHAN MTS (KYRGYZ REPUBLIC) AS A SOURCE OF PALEOCLIMATIC INFORMATION