A forest of glass
In the Allahuekber Mountains of northeastern Turkey, the Sarıkamış forest endures a climate of extremes. Winter temperatures here can plummet to lethal lows, with average daily highs in January hovering around -3.7°C (25.3°F) and lows reaching -11.8°C (10.8°F). The dominant tree, the Scots pine (Pinus sylvestris), has evolved a sophisticated defense against this cold, transforming its own cells to survive conditions that would kill most other plants. The primary danger of freezing is not the cold itself, but the formation of ice crystals within living cells. These sharp, expanding crystals puncture delicate cell membranes, leading to death. To prevent this, the pines of Sarıkamış employ a process that effectively turns their cellular fluid into a form of glass.
This process, known as vitrification, is the tree's primary defense. As temperatures fall, the pine actively pumps water out of its cells and into the intercellular spaces. Simultaneously, it dramatically increases the concentration of sugars, such as sucrose and raffinose, and amino acids like proline within the cells. This sugary solution has a much lower freezing point than water. When subjected to extreme cold, this intracellular syrup does not crystallize. Instead, it becomes an amorphous, glass-like solid. This glassy state prevents the formation of damaging ice crystals and protects the cellular machinery until the spring thaw.