Black locust   Thomas Diggins
  Oct 01, 2003 10:26 PDT 


Quick comment on your black locust example. The species is regarded as non-native
through much of the Northeast, and of course was widely planted for fence rows,
etc. However, it naturalizes readily, and has made its way into all sorts of areas
where it was never planted. This begs the question, How much would this species
have expanded its range without the help of humans? I wouldn't be surprised if
there are data on the post-glacial range expansion of black locust that might
suggest what would have happened absent wide-scale planting.

A second interesting point. Black locust doesn't seem to be highly regarded as a
timber species, yet it is virtually immortal in its resistance to rotting. I know
there are more than a few suggestions that black locust could be a replacement for
pressure-treated wood. I'm under the impression that the contorted growth form
usually limits board length and size (sounds like a potential application of
silviculture/artificial selection here).

BTW, black locust is a handsome tree.


The issue of whether red pine or any other species is "natural" is
certainly a fuzzy one. As the climate has changed during the past few
million years, many species have moved through the area- which may not
by "natural", that is "native" at this time, which to me, doesn't make
them "un-natural". Almost certainly, at some time in the past thousands
of years, red pine was "native" to the Quabbin area, even if none were
there when the pale faces showed up.


Oh, another species disliked by the species fundies is black locust. I
like black locust. I once saw some monster specimens on the Pittsfield
City Watershed, which have been cut. I think they were around an old
celler hole, so were planted by some old timer, probably in the
nineteenth century.

And, I've noticed black walnut "escaping" in south Berkshire County-
I've seen in seeding in on very fertile soils and I expect that it has
"gone native". The species fundies may object, but walnut is a great
species- why object to them?

Joseph Zorzin 
RE: Black locust   Joseph Zorzin
  Oct 01, 2003 10:56 PDT 

I just recently saw a slide show on an acre of black locust some other
forester was managing- he marked it for a thinning, another consultant
who does lots of trail and foot bridge work likes the wood, so he
brought in a tiny machine (something from Italy) and did the harvest. He
took some of the wood and a local framer took the rest for his exotic
framing work. I inquired about the economics of the project, but didn't
get an answer.

I sort of assume, unscientifically, that if any tree species which is
native anywhere in the east, gets planted somewhere else in the east and
shows some propensity to "escape", the odds are it was once there, long
before farmers planted them, so it's just a return, not an invasion- a
dangerous political claim by humans, but legitimate enough to me for

Regarding data on post glacier movement of the species, great question-
just the sort of thing that Dave Foster at Hah-vid Forest should be able
to answer, seeing that pollen analysis is his speciality, unfortunately,
he ain't here.

Now, isn't black locust in the legume family? So, I wonder if it also
can add fertility to the soil, like many other legumes? Whenever I see
one, I sort of think of it as a asset to the local environment- a rare
gem. The bark on the older specimens is amazing, the most convoluted and
corky of any bark I can think of.

Re: Black locust   Lee E. Frelich
  Oct 01, 2003 11:15 PDT 


I haven't seen any papers on migration of black locust. The problem is
that it is insect pollinated, which means that very little pollen shows up
in sediment, so extremely large pollen counts would have to be done, or,
even more difficult, macrofossils would have to be examined to determine
its rate of migration. Few sedimentary basins have the right environment to
preserve a lot of macrofossils (seeds, leaves, buds, etc.), especially as
compared to pollen from wind pollinated species, which is very decay resistant.

Black locust is extremely shade intolerant, and a nitrogen fixer, so it can
invade open disturbed areas with poor soil, and actually improve soil
quality. It can't invade established forests, and it is usually replaced
by more shade tolerant species within several decades.

Re: Black locust   Colby Rucker
  Oct 01, 2003 15:04 PDT 


Indeed, black locust has many positive qualities. It appears quickly on
roadcuts and abandoned "waste land", where it fixes nitrogen and fosters the
growth of more permanent trees, such as yellow poplar. Locally, black
locust can't compete for height, seldom going over 100 feet, but the dead
and fallen trunks persist and can be utilized for fence posts. I put in
over 500 in the early 1970's. I cut heavier ones for post-and rail, and
many are still in place, especially in the drier areas.

I also cut some larger ones into fifteen foot lengths and had it sawed 4 x
4. I picked out the clearest and straightest 4 x 4's, and cut the rest in
half for posts. The best pieces were amazingly strong for their size, and I
used them to crosshaul logs from jobs where it wasn't worth taking a boom
truck for a single tree. Also used them for supporting trees on houses,
pulling engines, etc. Left elevated, but exposed to the elements, they just
got harder, and were always reliable. I still have several of them. Small
diameter pieces of slow growth, cut from whitened snags, make wonderful tool
handles. Cut down with a hatchet and drawknife, they take a high polish,
and linseed oil brings out a grain of lasting beauty and high reflectivity.

Due to their straight grain, basal growth is in line with the roots. The
cross-section may be like a six-leaf clover, with exposed dead wood between
the roots. The Fomes fungus destroys the heartwood, so that some trees are
left standing on stilts, like your fingertips on a table top. The fungus
also produces large woody polypore brackets higher on the trunk, a sure sign
that the inner trunk has turned to a soft sulfur-yellow material, and
breakage is imminent. For BTU's, locust is only surpassed by osage orange,
and will bow cast iron andirons, and burn common iron right through.

The matter of natural range is interesting, but I don't subscribe to all
that's said. We can see that many species of field and roadside, such as
persimmon, redcedar, and black cherry, would, without agriculture, be
restricted to more specialized habitat where they could compete for
sunlight. Persimmon arches over marshes. Redcedar and black cherry do well
on sandbars. Black locust persists on exposed bluffs along tidewater. Dry
sandy ridges - impoverished soils - provide habitat for many intolerant
species, including black locust.

So, I see no reason why black locust wouldn't have been present at such
specialized stations, and why it wouldn't have then spread to agricultural
areas without introduction by man. Boundary markers in old deeds and
timbers in early structures indicate the use of locust by early colonists,
but I'm unsure of the dates.

Lastly, we might extend our usual timelines. We speak of pre-colonization
forests, the influence of Indians, warming in the last 10,000 - 12,000 years
of the post-glacial period, and the movement of forest types.
(Incidentally, forests can't be "pushed;" they are drawn). Shoreline
erosion along the Chesapeake Bay exposed numerous baldcypress stumps five
and ten miles from here. A 1917 photographs shows the stumps, some very
large, in perfect condition after being buried for 100,000 years - since the
previous interglacial period. And, fossils show many familiar species
millions of years ago.

My point is that our trees are prisoners of their genetics, perhaps changing
little, and derived from unknown forests long ago in unknown times. Our
trees are now making the best of their inherent capabilities, some perhaps
not so tall, or so grand, or so "happy" as once in the past. We really
don't know, but the black locust, on its own, appears to persist at sites
which are perhaps not numerous, and certainly challenging, but possibly more
widespread than claimed.

Yes, for all its faults, black locust is an interesting species.

Re: Black locust   Thomas Diggins
  Oct 01, 2003 15:05 PDT 

Lee and Joe,

Thanks for the posts. I hadn't thought about the insect-pollinated nature of black
locust. Too bad, because there are good lake sediment pollen data for a number of
other species that trace their recolonization from glacial refugia. These questions
of invasion vs. recolonization are debated in terms of fishes as well. For some
species, it's obvious how human activities fostered their spread, but for others
it's not so clear. Sea lamprey is a good example. It definitely invaded the Upper
Great Lakes via canals, but some biologists suggest it colonized Lake Ontario
through a post-glacial marine intrusion. Or... maybe it was the Erie/Oswego Canal.
Unfortunately, once the anthropogenic experiments of habitat alteration,
disturbance, commerce, agriculture, etc., have been started, it becomes
increasingly difficult to tease out their effects from those of previously (and
continually) operating non-human factors. My hunch is that black locust, especially
in light of its N-fixing pioneer abilities, would be a big-time range expander even
in the absence of human influence. Interestingly, it behaves in Zoar Valley exactly
as we would expect. It colonizes islands and gravel bars, sometimes getting quite
big, yet we've only found one tree within a closed-canopy old-growth area. And that
one tree is amongst bottomland sycamores and cottonwoods, and it is only about 50
feet from the river's edge.


Black locust - More
  Oct 01, 2003 15:44 PDT 


After your superb endorsement for the black locust, I may have to add it to my list of favorites. It was never far away. I delight in the fragrance of its blossoms and even find its brown seed pods rather attractive - in an odd sort of way.

My quest for tall black locusts has turned up the following.

Hgt State Circ

126.6 NY 7.1
117.6 NY 5.5
116.0 NY 6.2
114.2 MA 5.8
112.8 MA 5.8
112.3 MA 6.4
110.8 MA 4.0
109.0 MA 7.1
103.3 MA 4.6
100.3 MA 6.5
74.6 MA 13.0

Breaking 90 feet is relatively easy, but black locusts over 100 feet are scattered rather widely in New England.

Will has broken 150 in the Smokies. I don't recall what Jess Riddle's best is.

black locust
  Nov 23, 2003 18:01 PST 

In all of my travels, I have not seen black locust the likes of which grow in
the Dummerston and Putney, Vermont area.

The general Putney area is where many western Massachusetts and southern
Vermont apple growers traditionally got locust posts for the deer fences they
installed around their orchards.

Given the size of some of the locusts along the road sides, I can only
imagine what could be back in the woods.

In West Virginia, black locust can be a common pioneer species but it is
disease prone and often wrecked by grape vines. It is only on rare sites where
you will see locust over 20" DBH. It is not uncommon for trees to reach 80 or
90 feet but taller trees are usually only a function of competetion.

I am reasonably certain that I regularly see older black locust in New
England as a casual and infrequent visitor than I encounter on almost daily forays
into the West Virginia woods.

Black locust revisited
  Nov 23, 2003 18:40 PST 


That's really fascinating. I'm going to head up Putney way the first chance I get and measure some locusts. Dummerston is the site of a huge colonial white pine. Maybe the general area has some special growing conditions. BTW, do people in WV use black locust for fuel and if so, what is their opinion about it? I've read that black locust is second only to osage orange in BTUs, surpassing hickory and white oak.

Re: black locust
  Nov 23, 2003 18:41 PST 


That is truly fascinating. Eastern New York is loaded with large, tall black locusts. The species seems to thrive in the latitude of southern to northen New York, which would include Putney, VT. You've really peaked my interest. The first chance I get, I'm headed for Putney. It isn't that far.

BTW, the question you asked about the WV white ash in terms of its impact on the Rucker indexing process. It would be one of ten species that got averaged to comprise the index. The one you identified would make a handsome contribution to an index though.

A question that comes to mind about the species is: do people in WV use black locust for fuel and if they do what do they say about its properties? I have read that from a BTU standpoint, black locust ranks second only to osage orange, outperforming hickory and white oak.
Re: black locust
  Nov 23, 2003 18:53 PST 

In WV Locust is more prized for fence posts and rails than almost anything

Small sawtimber trees 14-16" DBH are often sawn for naturally rot resistant
decking lumber.

Hickory is favored for firewood with localized and highly variable oak

In much of the state, Osage orange is not native and quite scarce and I have
never heard of anyone cutting it for firewood.