Thursday, September 8, 2011

Dominating the landscape

     Last week, I wrote about tree age and response to drought. When I drove into work this morning, I noticed that our soybean crop provided the perfect example of how pecan trees come to dominate the landscape. In the photo at right, note the large native pecan tree marked with a yellow bar. The roots of this tree have suppressed the growth of the adjacent bean crop (out-competed the beans for water). The red arrow points to a distinctive line in the field of soybeans that marks the extent of the pecan roots domination over the bean crop. Even 60 feet away from the tree,  the beans are struggling for water. Outside the tree's influence the beans maybe drought stressed but the plants are 30 inches tall.  It is important to note that a tree's underground influence on its environment extends far beyond the "drip line" of the tree's canopy.