Soil Factors Related to Urban Sugar Maple Decline

Abstract

A study was conducted on soils surrounding forty roadside sugar maple (Acersaccharum) trees situated in an urban environment. The study examined the differences between declined and non-declined sites. Discriminant analysis implicated the following four soil properties with decline: depressed levels of exchangable K, elevated levels of exchangable Na, high total soil N, and a lower component of sand. In addition, thin sections of soil indicated a reduction in macropore space in the upper surface of crusted or compacted soil. Soil crusting and compaction appeared to be directly related to the devegetated condition of soil bordering roadways. The frequency with which decayed roots were found along roads, and under crusted or compacted soil, and in some cases the absence of any roots, suggest a possible root/shoot imbalance. Root mortality is likely the result of the interaction of low oxygen, low moisture, and high Na levels in encrusted or compacted soils.