Very little mechanical damage was observed in the Park. Even broken tree tops, occurring from wind stress, were found to be less common than expected. The one exception that was observed, albeit not a serious condition, was that some trees have experienced some animal rub damage. A few redwood trees along the Big Trees Trail between Areas “I” and “J” lying just west of Skyline Boulevard have scuffed bark at two to six feet above ground level. This condition is not uncommon in forests where bear and often elk will return to a favorite tree to scratch themselves. The result is often that most of the bark gets rubbed off, and damage occurs to the underlying cambium layer. Trees do not usually die from this; however, their growth is often retarded. The trees observed in the Park had very light damage that was likely caused by horses hobbled in this area by equestrian users. This situation should be monitored in the future to insure significant damage does not occur.

Pathogens, rots and insect infestations, are less common in redwood than in other tree species occurring in this region. However they do occur. Often rot causing fungus will be introduced through a mechanical wound on a tree. The redwood trees in Joaquin Miller Park appear more resistant than average to effects of rot. Even where the base of a tree was observed to have damage that may expose the tree to a fungal infection, very little to no rot was observed. No problems with pathogens were observed.

No specific areas were observed that could be identified as significantly different from overall conditions observed in the Park trees relative to tree vigor, mechanical damage, or pathogens.

A total of twenty trees were bored to determine age and growth rate. Table 3 shows tree bore data including sample location, diameter at breast height (DBH), total height, and radial growth increments for five year time periods. Trees were sampled in areas “F, H, I, J", and "K” (Figure 1). Areas “D" and "E” were found to have very few redwood trees, those located were small saplings which were in good health and growth status. Area “G” exhibited significantly lighter trail use than other areas surveyed and was not sampled. Sample trees were selected from the heavier use trail areas. Trees were selected for growth measurement that were immediately adjacent to trails and had exposed roots on the trail (see Figures 3 and 4); and also trees located approximately 30 feet off the trail where the tree base was unaffected by trail use compaction and disturbance, but the tree crowns essentially occupy the same space as the trail adjacent trees.