A tree seems like an unlikely historian. It cannot write, speak, or remember in any human sense. Yet inside the wood of an old tree is a remarkably detailed record of the world in which it lived. Year after year, trees respond to temperature, moisture, sunlight, competition, fire, insects, disease and other environmental pressures. When those responses are preserved as growth rings, scientists can sometimes reconstruct not merely the life of an individual tree, but portions of Earth's environmental history extending back thousands of years.  
  
The science is called dendrochronology, and its most fundamental trick is beautifully simple: trees in suitable environments generally produce growth increments in a recognizable annual sequence. Researchers compare patterns of unusually wide and narrow rings among many trees, matching overlapping sequences to create a chronology extending farther backward in time than the lifespan of any individual tree. This process, called cross-dating, can link living trees with dead wood, ancient stumps, archaeological timbers and even submerged or buried wood. In some regions, these overlapping records extend through much of the Holocene. European oak chronologies, for example, reach back more than 10,000 years in some sequences.  
  
What makes tree rings especially valuable is their resolution. A lake sediment core may tell us that a period was unusually dry, for example, but a well-preserved tree-ring sequence can potentially show which individual years were dry and how severe the stress was... More> [https://www.patreon.com/DreamerBooksAnIceAgeSaga/posts/trees-as-time-at-167404679?utm\_medium=clipboard\_copy&utm\_source=copyLink&utm\_campaign=postshare\_creator&utm\_content=join\_link](https://www.patreon.com/DreamerBooksAnIceAgeSaga/posts/trees-as-time-at-167404679?utm_medium=clipboard_copy&utm_source=copyLink&utm_campaign=postshare_creator&utm_content=join_link)

Trees as Time Capsules