, it is pointed out that land plants are descended from aquatic plants.

dating of events from tree growth and wood structure-53

This required the physiological and morphological complexity found among the vascular plants.

provide structural anchorage to keep trees from toppling over.

Because organic soils were not widely developed, the earliest terrestrial plants probably first colonized bare rock near large water sources, such as oceans and lakes.

Generations of these plants recycling nutrients (e.g., nitrogen, carbon, and oxygen) and energy into the stratum contributed to the development of a rich organic soil suitable for large shrubs and herbs.

In 1859, the German-American Jacob Kuechler (1823–1893) used crossdating to examine oaks (Quercus stellata) in order to study the record of climate in western Texas.

During the first half of the 20th century, the astronomer A. Douglass founded the Laboratory of Tree-Ring Research at the University of Arizona.

Some of the possibilities and dangers of this method of dating are discussed.

(den-droh-cruh-NOL-uh-gee) means “the study of tree time.” Usually called tree-ring dating, dendrochronology is a science based on the fact that every growth season a tree adds a new layer of wood to its trunk.

Dendrochronology (or tree-ring dating) is the scientific method of dating tree rings (also called growth rings) to the exact year they were formed in order to analyze atmospheric conditions during different periods in history.