Tree Height, Cavities, and Water  

TOPIC: Tree Height, Cavities, and Water

== 1 of 7 ==
Date: Mon, Aug 25 2008 11:59 am
From: Josh Kelly


We are in the midst of the most severe drought in recorded history
here in western NC. Most streams are flowing at less than 1/6th of
their average volume for this time of year. Yet, while coring many
trees as part of an old-growth forest research project last week,
Kevin Caldwell and I found that many trees, both hollow and solid,
were storing dozens of gallons of water in cavities and even heart
wood. This led to some speculation about whether these water filled
cavaties and saturated sections of wood were available for the tree to
use. Most of these trees were oaks, and I doubt they have the ability
to root into these cavities, and they may not have a mechanism to
transfer water into their cambium layer from these reservoirs. A
yellow birch or sitka spruce however, could potentially root into one
of its own cavaties that held dozens of gallons, and if that cavity
was high enough in a tree, it could help relieve water stress during
droughts and increase the maximum height potential of individual

Are there documented cases of trees using water stored in cavities and
hollow boles?

Are there ways in which trees could access these reservoirs without
adventitious roots?

Hopefully some of you can help me answer these questions. Thanks.


== 2 of 7 ==
Date: Mon, Aug 25 2008 12:05 pm

I have wondered about this also, as one who has 'cored' enough trees to have been 'deluged' from such reservoirs. I have not read anything that would suggest that these reservoirs 'serve' a is my current supposition that water just goes were it can, and if there's no outlet, it merely remains there. Perhaps the bigger mystery is how much protection the tree provides those reservoirs, through seriously cold, winters when one would expect the expanding reservoirs to crack open, splitting trunks...

== 3 of 7 ==
Date: Mon, Aug 25 2008 3:22 pm
From: Lee Frelich

Don, Josh:

I doubt that trees can root into these internal cavities with wet wood,
because there is cambial tissue that could form buds in old xylem tissue. I
think its just water that is disconnected from the trees circulation system
and can't go anywhere.


== 4 of 7 ==
Date: Mon, Aug 25 2008 6:50 pm
From: Josh Kelly

Don, Lee,

Thanks for your thoughts. The water from the reservoirs within most
oaks has a high tanin content (it stains one's skin and clothing
black) indicating that it has been sitting there for a while. I would
not be surprised to learn of a tree, Ficus perhaps, that could take
advantage of a reservoir of water in a cavity.

The thought also occured to me that many of the trees that explode
upon being struck by lighting probably have internal reservoirs of
water that are instantly vaporized and blow the tree apart.


== 5 of 7 ==
Date: Mon, Aug 25 2008 8:35 pm
From: Randy Brown

If anyone is curious here's a useful site for looking at drought

I've seen lots of horribly topped/pruned silver maples grow adventious
roots into their own cavities
but haven't noticed any other species do this.

== 6 of 7 ==
Date: Mon, Aug 25 2008 11:22 pm

Presumably it's a tree's natural extractives that mix in with the reservoir fluids that keeps them from freezing and cracking the bole open, in cold climate environs?

== 7 of 7 ==
Date: Mon, Aug 25 2008 11:29 pm

While I don't have the URL on the top of my head, there's a great compendium of tree ring analyses that has been used to correlate the differences in tree rings over time to known climate data, then used to support climate proxies going back hundreds and some cases thousands of years. The graphics they use are very similar to the isobar graphs in your useful drought webpage...

TOPIC: Tree Height, Cavities, and Water

== 2 of 3 ==
Date: Tues, Aug 26 2008 4:54 am
From: neil

Hi Josh, Don, Randy, et al.,

I've only heard anecdotally from my plant physiology adviser that
trees can store more water in when larger; this was in reference to a
paper that suggested seeing changes in water use efficiency in trees
through time. I recently heard at a conference that trees can take
water up one side of the tree, pass it up and over the top of the tree
and 'provide' it to the other side of the tree. Still gotta find that
paper. This is all to say that it would not surprise me if trees
'found a way' to tap into stored water. Now, whether they could tap
into water behind compartmental walls that 'seal off' a wound is
another thing.

Drought: Indeed, tree rings are used to reconstruct drought for much
of North America - Mexico to Canada:
- a link at the bottom of that page goes to the reconstructions
revised for 2008. It is one heck of a network. Annual maps and time
series are available.


== 3 of 3 ==
Date: Tues, Aug 26 2008 2:24 pm
From: Lee Frelich


A lot of such trees actually do crack open, and then no longer hold water.
When I have cored trees in below zero weather, the sap has been frozen
quite solid. I suppose there might be some cavities that don't freeze
because wood is such a good insulator and there may decomposition and
animals living in there that generate heat. Some trees also have extra
space inside that the water can expand into if it freezes.


TOPIC: Tree Height, Cavities, and Water

== 1 of 1 ==
Date: Wed, Aug 27 2008 5:25 am
From: Randy Brown

Neil & Don,

Thanks for the drought history link. does look interesting.

TOPIC: Tree Height, Cavities, and Water

== 1 of 1 ==
Date: Thurs, Aug 28 2008 2:06 pm
From: Russ Carlson

There are several possibilities for the water sources. One, of course,
is water that is just standing in cavities within the tree. The other
is wetwood, pockets of high fluid concentrations within the wood. This
is often associated with bacterial infections. The fluid is often dark
and with a strong odor. It is not a pleasant ride home after getting
drenched when you break the pocket.

Water within the tree won’t be absorbed in any quantity by surrounding
wood. Most trees will develop adventitious roots in response to
wounding, and those roots will make use of water and organic matter that
collects in decay pockets. But if there is no wounding, the roots
probably won’t develop.

Russ Carlson, RCA, BCMA
ASCA Registered Consulting Arborist #354
ISA Board Certified Master Arborist PD-0008B