To date, subfossil pines have been investigated in two bogs of Lithuania: Didysis tyras and Užpelkių tyrelis. Pine wood from "Užpelkių tyrelis" enabled the construction of a long-term chronology spanning 2145 years. This bog is situated in northwestern Lithuania (47 km from the Baltic Sea). More than 300 specimens of well-preserved pines were collected in 1971-1972. Excavated trees were of different ages, on average - 107 years old. Cross-dating of pine wood revealed that a strong similarity in growth fluctuations is characteristic of a smaller part of trees. That is why only about half of the trees (47 %) were successfully crossdated. As a result, five chronology fragments (173 BC–AD 593, AD 551–837, AD 951–1148, AD 1143–1474, AD 1773–1924) were constructed. The youngest fragment is precisely dated against living pine trees and older - relatively dated by radiocarbon. The longest gap in the chronology is recorded at the end of the 15–18th century. In that period, named "Little Ice Age", ground water increased due to low temperatures. It could be stated that optimal ecological conditions for pine growing in peat bog were in 1–3rd, 7–8th and 11th c. Cold and humid conditions predominated until the 1st BC, 4th, 5–6th, 9th, 12th and 16–18th centuries AD (Pukienė, 1997; Pukienė, 1998; Pukienė, 2001; Pukienė and Bitvinskas, 2001).
In addition, dendrochronological research has been carried out on subfossil pine timber found in Lake Stirniai, northeastern Lithuania. As a result, a tree-ring floating chronology spanning 213 years was compiled. Radiocarbon dating of the samples has shown that pines lived in the transition between the Medieval Warm Period and Little Ice Age (from 1103 ± 80AD to 1315 ±80 AD). Research has revealed that pines grew on peat soil, likely on Pinetum carico-sphagnosum forest type. It was discovered that the water level of Lake Stirniai in the Medieval Warm Period was probably below about 1.0 m than nowadays. Analysis of cyclic recurrence of the annual radial growth fluctuations of pinewood growing on boggy soil along Stirniai lakeside in the 12–14th centuries enabled the determination of at least six cycles longer than ten years (Stasytytė et al., 2005).