This dataset comes from a study of symptoms of crown dieback, cankers
and symptoms caused by other pathogens and pests in ash trees (Fraxinus
excelsior). In all 454 trees were observed in two plots. There are 8
categorical variables, 6 of which are binary and two are trichotomous
with values representing increasing severity of symptoms, and one
continuous variable, tree diameter at breast height (DBH).
Usage
data(ashtrees)
Arguments
References
Skovgaard JP, Thomsen IM, Skovgaard IM and Martinussen T (2009).
Associations among symptoms of dieback in even-aged stands of ash (Fraxinus excelsior L.).
Forest Pathology.