Mixed effects of climate variation on the scots pine forests: Age and species mixture matter.

Highlights • The spatial vulnerability of Romanian Scots pine stands to climate change impact is quantified. • A unique country-scale dendroecological network was developed and used. • Too hot and dry August climatic conditions trigger negative growth anomalies. • Relatively young Scots pine monocultures located below 1000 m a.s.l. in the western part of the Romania are most vulnerable. • To enhance the resilience of forest ecosystems we need to refine future forest management strategies. Abstract Understanding and unravelling the direct and indirect effects of ongoing and predicted climate change on the vitality and productivity of Scots pine forests is particularly important for Romania and other parts of eastern Europe, where the species represents an essential ecological and economic value. Here, we introduce the first nation-wide network of 34 Scots pine chronologies of basal area increment (BAI), and assess the species' vulnerability to climate change. Temperatures of the previous autumn, as well as current year spring and summer warmth are found to be most critical for the productivity of Romania's Scots pine forests. Negative growth anomalies after hot and dry August conditions are most severe in young (<50 years) Scots pine monocultures (>70% dominance) at lower elevations (<1000 m a.s.l.) across western Romania. Our findings emphasise the relevance and timeliness of carefully adapting sylvicultural management strategies to enhance the ecological and economic resilience of Romania's widespread forest areas under a warmer and drier future climate. [ABSTRACT FROM AUTHOR]