Drastic changes in climate have occurred many times in Earth's history. There is direct fossil evidence of global cooling that took place 35 million years ago, when a tropical climate shifted to a temperate one.
Upriver towns in the valley depended on the Willamette River for a connection to the outside world for decades before the railroads were built. Today much the the hustle and bustle of early city life has been replaced by agriculture. Periodic flooding has taught people to remove permanent structures from the floodplain.
Extreme weather events define which plants and animals can live in a place. Last week's big freeze defined the limits of cold weather in our area. The West Eugene Wetlands is now recovering from the freezing weather but there may be more to come.
As the fierce, icy heart of winter approaches plants and animals find shelter and food in newly created spaces. The leaf litter in the Cottonwood forest harbors an abundance of life during the wet, cold months.