Drunken trees are a stand of trees displaced from their normal vertical alignment. This most commonly occurs in northern subarctic taiga forests of black spruce under which intermittent permafrost or ice wedges have melted, causing trees to tilt at various angles. Some trees survive their soil eroding and continue to grow. Others collapse or drown as the subterranean ice melts. As they are staggered across the landscape, people often refer to them as ‘drunken trees.’
Drunken Trees are also called, tilted trees, or a drunken forest may also be caused by frost heaving, and subsequent palsa development, hummocks, earth flows, forested active rock glaciers, landslides, or earthquakes. In stands of spruce trees of equal age germinated in the permafrost active layer after a fire. The tilting begin when the trees are 50 to 100 years old, suggesting that surface heaving from new permafrost aggradation can also create drunken forests.
What is Permafrost?
Permafrost soil or rock remains below 0 °C for at least two consecutive years. It forms a solid matrix in the soil which can spread to a depth of hundreds of meters. Permafrost is permanently frozen ground. Nonetheless, climate change has caused much of that ground to melt at an unprecedented rate.
The ground buckles and sinks, causing trees to list at extreme angles. Further, the permafrost prevents trees from developing deep root systems. Also, those areas where the permafrost temperature is close to the melting point of water.
Drunken Trees Relations with Climate Change
The climate variations, or loss of surface vegetation from fire, flooding, construction, or deforestation, can thaw the upper extents of the permafrost. This is creating a thermokarst, “the scientific name for a ground slump caused by melting permafrost”. The thermokarst undermines the shallow root bed of trees, triggering them to lean or fall. Thermokarst lakes are enclosed by a ring of drunken trees leaning toward the lake, which makes these land features simply identifiable. When permafrost melts, it affects a lot of erosion; a lot of trees can’t stand up straight. If the erosion gets worse, everything goes with it.
Drunken trees may ultimately die from their displacement, and in ice-rich permafrost. The entire drunken forest ecosystem can be damaged by melting. Drunken trees are not totally new phenomenon dendrochronological evidence can date thermokarst tilting back to at least the 19th century. Permafrost is naturally in disequilibrium with climate, and much of the permafrost that remains is in a relict state.
However, the rate of thawing has been increasing, and a great deal of the remaining permafrost is expected to thaw during the 21st century. At times the trees survive the pressure and continue growing, uprighting themselves to vertical. However, on the other side, trees collapsed or drown from rising water tables as subterranean ice melted. Because such trees seem to stagger across the landscape, people often call them “drunken trees.”
Moreover, Al Gore cited drunken trees caused by melting permafrost in Alaska. This is another piece of evidence of global warming, as part of his presentation in the 2006 documentary film An Inconvenient Truth. Alike warming leading to permafrost thawing in neighboring Siberia has been credited to a combination of anthropogenic climate change, and a cyclical atmospheric phenomenon known as the Arctic oscillation.
Moreover, the albedo positive feedback caused by both when melting ice expose bare ground and ocean which absorb, rather than reflect, solar radiation. The melting permafrost isn’t just affecting the trees. But it is also having an enormous impact on the people that live and work in the zone. Thus, slumping land cracks pavement breaks pipelines, and causes sinkholes to open, swallowing roads, and buildings.