Although the loss of trees during this unusually violent Santa Ana windstorm may have been inevitable, we know that many of our trees were at high risk because of how we select, plant, and care for them. Trees fail because we baby them. We over water them so they don't have to develop deep, broad, supporting roots to get water. We water frequently and for short periods so the roots grow near the surface, where the water is. Furthermore, when the winds came trees standing in soggy soil may have been an easy push-over.
We stake trees when they are young under the misconception that this will result in stronger, straighter trees. Not so! They cannot sway and move, and this is what is needed for the development of a strong root system.
We prune trees badly so the growth above ground is not in balance with the roots below. After severely pruning a tree, there is not enough energy generated through photosynthesis to feed the root system. The tree may respond with a flush of growth above, even though the roots are diminished. It takes time for balance between the top and bottom to be restored, but we just keep hacking away at the branches, year after year.
And of course, we plant fast growing trees because we can not wait for a steady oak to grow. Though this may provide quick gratification, especially when water and fertilizer further accelerate growth, the results are brittle, unstable, shallow-rooted trees that stand hazardously next to our homes.
Kids and adults stand around shallow, broad roots of uprooted pine. |
Broken roots of oak |
Workers remove debris. It would be nice if the material was chipped and recycled right here in Garfield Park, the place it grew. |
Children say good bye to trees. |
Emily Green, Why did santa ana winds fell so many trees?
Emily Green, Now that the winds have departed.
KPCC, Santa Ana winds blow through Southland toppling trees, power lines
LA Times Photography
Great post, Barbara. Thank you.
ReplyDeleteReally sad to see all those downed trees. And really sobering.
ReplyDeleteThat is an interesting observation. We had an early snow storm here in Buffalo NY 5 tears ago and 90% of the trees here were damaged or destroyed...old trees..it was heartbreaking...We didn't lose any but had damage and we don't water any of our property and are planting natives to replace non-natives....Michelle
ReplyDeleteI think it's also important to note the effect of soil compaction on urban tree root growth. Often, areas to be developed are artificially compacted to prepare for development, and subsequently the weight of structures, hardscapes, etc. makes the compaction worse. That's why the work that's been done at Cornell and other places on "structural soils" for urban tree installation is so important. If these problems aren't addressed at the time that trees are initially installed, there is little that can be done after-the-fact (for instance, by changing watering regimes) to alter the fundamental structure of the soil. See the article "Growing Trees in a Cement Forest" for more information from Cornell researchers: http://www.lowney.com/clientZone/articles/updates/updateCementForest.shtml
ReplyDelete@theparsley, Yes! Soil compaction really does matter. In this park the soil is compacted because it is often wet and people walk and run on it all of the time. I am not sure the "structural soils" would have worked in this case since these weren't parkway trees and I can't see how that kind of soil replacement in this open field could be accomplished. I think that the over watering was bad for many reasons and the soil compaction is probably not the least of it.
ReplyDeleteEven without compaction, or supplemental irrigation, I was impressed at the number of massive trees that were downed even here in last week's storm. I agree though, these manicured park areas very much shorten the lives of some of these beautiful trees, especially our oaks. That last photo is just heartbreaking.
ReplyDelete