Categories: Expeditions Date: Jan 15, 2009 Title: Black Walnut
Q: Where is the largest Black Walnut in the world? The woodlands of Texas? The hills of Missouri? Tennessee? A: On a river island in Oregon famous for its pumpkins.
06/09/07 Will Koomjain
The Sauvie Island Black Walnut is somewhat of an anomaly in the tree world; almost all world champion trees are found squarely within the native range and habitat for the species. The Black Walnut (Juglans nigra) live in conditions that they have evolved for millions of years to thrive within. None the less, the world's largest black walnut lives not in the eastern U.S., where it is native, but on a sandy island in the Columbia River just down stream from Portland, OR.
Early that Saturday morning we drove out to the tree, which grows on land belonging to a private resident. We first contacted them as they were still moving in, and yet unaware of the tree's special distinction. They told us that the presence of the many mature trees on the property had been a factor in buying the house, and they were excited to be the stewards for such a famous plant.
We laid our gear out on the large lawn under the tree and promptly set a line at approximately one hundred feet over one of the main arched leaders of the tree. Upon ascending that line we noticed that the highest point on the tree was not the trunk we were in, but in another trunk about fifty feet away. We made our way to that trunk to take a height measurement.
Then we descended into the lower canopy in order to investigate the lower branch structure. The structure was complex and unique.Many of the branches spread out horizontally to notable lengths, but one in particular caught our attention. It came off the trunk at about fifteen feet up and was without a doubt the longest horizontal branch we had ever seen. We found out later that this ninety-two foot long branch had been measured previously by Dr. Robert Van Pelt and declared to be the largest known self-supporting branch in the Pacific Northwest.
Another notable feature of the tree were the many branch fusions. Branch fusions occur in places where branches rest on each and eventually grow together creating a natural brace. We surmised that without these connections many of the branches would not be able to support their considerable weight.