Sound like a good idea. However the redwoods are not in the best health. If you notice sometime last year the mulching area has increased in the area you are suggesting. Talking to the park employees it was to protect the top roots and other aspects of the tree from the already high traffic they receive. Adding more traffic may cause those redwoods to come down at some point.

We did move picnic tables, do to severe compaction from foot traffic over root system, we are trying to improve root system for health of tree's.
Bill Hudson
Parks Maintenance Supervisor

Please see posting comment 04/24/18

Interesting point about protecting the roots. That sounds nice but I'm not sure that is the primary issue. The park benches have been there a long time, and lots of kids have climbed those same trees for a long time. Only in the last few years have the trees in that grove really taken a turn for the worst.

Was a determination made that a trampled root system was the primary culprit? How do insufficient water and/or disease play into the current state?

Water - The city stopped watering the parks during the drought, which, although I understand the reasoning, was a shame. Redwoods need moisture. With changing weather, we are not getting the fog we used to get so we have to supplement with more water. These trees are gone if the park doesn't step up the watering to compensate for the lack of fog, no matter how much mulch we put down.

http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=7948

Disease - I am not an arborist or biologist so have no idea if this is part of the explanation for the browning at Franklin or not, but it seems likely given the strange pruning patterns I've noticed on some of the more sickly trees.

http://homeguides.sfgate.com/brown-leaves-redwoods-64362.html

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