This information can be related back to records of stream flow characteristics for those years. As a result of this comparison, scientists can determine exactly how flow patterns affect growth. Some trees are scarred during periods of extreme flooding. Scars appear as indentations in rings on the upstream side of the tree. They occur when debris slams into the tree as it surges downstream during a flood.
Environmental scientists use tree ring cores to derive climate history.
Arizona's widely varying conditions and the hard life of southwest species like mesquite result in irregular growth that makes it difficult to obtain a reliable core. Instead, researchers study slabs, like the one shown here. Balancing Act Shafroth uses these clues and others to determine the best release patterns for a healthy riparian system. Once he gathers enough information, he will make recommendations to the U.S. Army Corps of Engineers, which manages the Alamo Dam. Alamo Dam provides a perfect work site for Shafroth.