Q: What are the East Slovak wooden churches made of?
Most of those churches belong either to the Greek Catholic Church – often called Byzantine in the U.S. – or to the Eastern Orthodox Church. They date back to the 17th-18th centuries, one is about 500 years old. Out of about 40 such churches in North-East Slovakia, four are on UNESCO's World Heritage List – Bodružal, Hervartov, Ladomirová, and Ruská Bystrá (along with one Roman Catholic and three Lutheran wooden churches elsewhere).
The wooden churches were usually built of needle trees: most often of larch, whose sap content makes it particularly durable, less so of fir, spruce, or yew (e.g., the oldest of the wooden churches in Hervartov); occasionally of deciduous trees – oak, hornbeam, birch, poplar.
Their bell towers were sometimes built separately, but within the fence around the church.
Dendroclimatologists from the Swiss Federal Forest, Snow, and Land Research Institute matched tree rings in Slovakia's historical wooden structures and forests to map out weather variations around the High Tatras over the past millennium.
May-June temperatures with markers of the warmest and coldest years and decades in northern Slovakia from 1040 CE through 2011 compared to the 1961-1990 average ("zero").