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UC Master Gardener Tree Stumps

Master Gardeners find urban tree stumps, evaluate the visible wood decay and then enter the information into an online database. The presence of decay is an element of tree risk assessment, which is used in urban tree management (retention/removal). 

In this citizen science project, MGs find, evaluate, and enter into an online database information on urban tree stumps. The project includes three components: (1) a training (via webinar), (2) field data collection (via an online survey, that can be completed on a smartphone), and (3) yearly data review and refresher training.

The question we are trying to answer: “What is the prevalence of visible wood decay (at base) in removed urban trees?”  In other words, when we look at a reasonably fresh tree stump, do we see decay (and what kind of decay is it: hollow stem; decay on the outside of the stem; or some combination); AND what are the basic characteristics of the stump we are looking at (size, position in the urban landscape, etc.).

And WHY would we want to know this: Because the presence of decay is an element of tree risk assessment, which in itself is a formal process that has a great influence on urban tree management (retention/removal). Yet, there are no recent studies documenting the prevalence of decay in urban trees (i.e., is decay something that is the usual condition in urban trees, or is it an exceptional occurrence). This is the kind of information that is quite common in “regular” commercial forestry (because the volume of marketable lumber is directly affected by wood decay), but the same information is rather lacking in urban forestry. Let’s change that!