If your favorite tree begins to show signs of thinning foliage or branch dieback, check where the natural gas pipeline is located. Gas leaks are often associated with declining trees, especially in older, established neighborhoods where pipes may be corroded or cracked. Leaking gas can drive most or all of the oxygen from the soil. Tree roots need oxygen for respiration and will begin to die if deprived of it. As roots die, branches and leaves soon begin to suffer.
Trees damaged by gas leaks initially exhibit sparse, stunted, yellow-green foliage.
On most healthy trees, you shouldn't be able to see a lot of blue sky if you stand next to the trunk and look up. On trees damaged by gas, you can. Chronic exposure to gas leaks will lead to branch dieback, weak shoots sprouting from limbs or the trunk, an overall decline, and finally death. This process normally progresses over a period of months or years, but rapid tree death may also occur if the leak is large. All trees and shrubs within 20 or so feet of a leaking gas line may be damaged, but large trees with deep root systems, such as pin oaks and pines, are particularly susceptible.