"What is a Carolinian Forest?"
|An avid gardener with an interest in
natural history walks into an Ontario garden centre and asks to see some
Carolinian species. The centre carries, among others, american beech,
tuliptree, carolina poplar and rhododendron caroliniense. Which of these
should be offered for purchase? Unsure? Confused? You are not alone.
Forester, landscaper, naturalist, biologist, neighbour and friend alike
can be perplexed by this term (and if they're not they should be, as we
will see). So ask us which of the above species are Carolinian and we
would safely say only that the rhododendron isn't native and the poplar
is a horticultural hybrid.
How did we reach this muddle; who do we
blame? Let's start way back in 1629. In that year King Charles I granted
his attorney general Sir Robert Heath the southern part of the English
claim in America called the Province of Carolana (land of Charles). In
some fashion, not explained in encyclopedias, this was corrupted to
Carolina. Then the area was chopped into a North and South to become the
states we like to golf in today.
|Historical Origins of the
But back to biology - in 1859, J.G.
Cooper used the term Carolinian to describe a forest region running in a
strip along the Atlantic coast from southern Long Island to Georgia.
This appears to be the first use of the term in a biological rather than
geographical sense. In 1892, J.A. Allen used Carolinian for a faunal
region stretching from the Carolinas to New Jersey and west to South
Dakota and Oklahoma. Both Allen and Cooper excluded southern Ontario
from their Carolinian regions. In 1898 C.H. Merriam published his
influential 'Life Zones and Crop Zones of the United States'. Merriam
used isotherms as well as plant and animal ranges to define a Carolinian
Area. "Counting from the north - the Carolinian Area is that in
which the sassafras, tulip tree, hackberry, sycamore, sweet gum, rose
magnolia, redbud, persimmon, and short-leaf pine first make their
appearance together with the opossum, gray fox, fox squirrel, cardinal,
Carolina wren, tufted tit, gnatcatchcr, summer tanager, and
yellow-breasted chat. Chestnuts, hickory nuts, hazel-nuts, and walnuts
grow wild in abundance."
Merriam's study correlated crop
adaptability with the life zones of the native plants and animals. For
example, peaches do well where chestnut grows. Southern Ontario from the
north end of Lake St. Clair to the west end of Lake Ontario was included
in his Carolinian Area.
1915, Canadian researchers Macoun and Malte used Carolinian to identify
the vegetation in southern Ontario bounded by "a line running
approximately from the northern shore of Lake Ontario to Windsor".
They characterized the vegetation as "the Hickories (6 species),
the Oaks (10 species), the Black Walnut (Juglans nigra), the Chestnut (Castanea
dentata), and the Sycamore (Platanus occidentalis). Less abundant and
more local in their distribution are: Cucumber tree (Magnolia acuminata),
Tuliptree (Liriodendron tulipifera), Flowering Dogwood (Cornus florida),
which have all beautiful and very conspicuous flowers, Papaw (Asimina
triloba), Red Mulberry (Morus rubra), American Crab Apple (Pyrus
coronaria), Sour Gum (Nyssa sylvatica), Sassafras (Sassafras variifolium)
"The herbaceous vegetation is very
rich, at least a hundred species occurring nowhere else in Canada being
found in the zone. A few of the most conspicuous may be mentioned, viz.:
Yellow Nelumbo or "Lotus Flower" (Nelumbo lutea), May Apple (Podophyllum
peltatum), Wild Lupine (Lupinus perennis), Tick Trefoil (Desmodium),
Flowering Spurge (Euphorbia corollata), Swamp Rose Mallow (Hibiscus
Moscheutos), Wild Pansy (Viola Rafinesquii~, Prickly Pear (Opuntia
Rafinesquii~, Poke Milkweed (Asclepias phytolaccoides), Wild Potato Vine
(Ipomoea pandurata), Downy Phlox (Phlox pilosa), Waterleaf (Hydrophyllum
appendiculatum), Bee Balm (Monarda didyma), Foxglove (Gerardia
pedicularia, G. virginica),Tall Bellflower (Campanula americana), Great
Lobelia (Lobelia siphilitica), Ironweed (Vernonia altissima, V.
illinoensis), Dense Button Snakeroot (Liatris spicata), Prairie Dock (Silphium
terebinthinaceum), Cup Plant (Silphium perfoliatum), Sunflower
(Helianthus decapetalus, H. divaricatus), Tall Coreopsis (Coareopsis
tripteris), Indian Plantain (Cacalia tuberosa). Golden Seal (Hydrastis
canadensis) and Ginseng (Panax quinquefolium) were at one time abundant
but are now practically extinct."
In 1938 another Canadian, John
Adams, mapped an "Interlacustrine or Carolinian Region"
with a northern limit along a line from approximately Toronto to
Sarnia. He listed most of the same species as restricted to the
region as Macoun and Malte. Finally Dice (1943) defined a
Carolinian Biotic Province which essentially followed that of
Allen & Merriam but excluded most states west of the
Mississippi and included Ontario below a line from Grand Bend to
After this the term should have gone off
to die in some biogeographical boneyard because other terms were
ascendent. For example W. Halliday (1937) in his 'Forest Classification
for Canada' outlined a Deciduous Forest Region described as "The
rather low-lying portion of the Ontario peninsula, enclosed by lakes
Ontario, Erie, and Huron... The associations are predominantly composed
of broad-leaved trees. A large number of these species, many of small
size, find their northern limit here. Amongst these are chestnut,
tuliptree, mockernut and pignut hickories, chinquapin, chestnut,
scarlet, black, and pin oaks, black gum, blue ash, magnolia, papaw,
Kentucky coffee tree, redbud, red mulberry, and sassafras. In addition,
within this Section is the main distribution for Canada of black walnut,
sycamore, swamp white oak, the shagbark hickory, together with the more
widely distributed butternut, bitternut hickory, rock elm, silver maple,
and blue beech.
|All these species occur as scattered
individuals or groups, either on specialized sites or within the
characteristic association for the Section. This association, made
up of widely distributed broad-leaved trees common in part to both
the Great Lakes - St. Lawrence and the Deciduous Forest Regions,
consists primarily of beech and sugar maple, together with
basswood, red maple, and (northern) red, white and bur oak. The
presence of the species listed above, and the predominance of
beech within the characteristic association, indicate a definite
relationship to an Ohio centre of distribution. Coniferous species
are poorly represented. . .
"Within the Deciduous Forest Region,
Halliday mapped a single 'Section' which he called the Niagara Section.
[J.S. Rowe in his Forest Regions of Canada (1959, revised 1972) followed
Halliday's work and retained the Niagara Section of the Deciduous Forest
Region.] In 1950, noted forest ecologist Lucy Braun mapped the area
south of the Toronto-Grand Bend line within the Beech-Maple Forest
Region of her Deciduous Forest Formation. Why Beech-Maple? The idea was
that a mature landscape (ie. well-drained would have a Beech-Sugar Maple
community at the termination, the climax, of plant succession. She was
clearly influenced by the earlier work on succession and climax
communities by Weaver & Clement (1938). This was a time when the
concept of climax vegetation was embraced by biologists eager to bring
order from nature's chaos.
Definitions of the "Carolinian Zone"
So now, at Mid century, Carolinian seemed
headed for extinction but instead it was merely extirpated from most of
its former range. The reprieve came at the hands of two Canadian
academics, J.H., Soper and W.S. Fox.
Soper was curator of the herbarium at the
University of Toronto and Fox was retired from the presidency of the
University of Western Ontario; you may remember him as author of
"The Bruce Beckons" or "T'aint Running No More" (or
something like that). From 1952 to 1954 they published three papers
entitled "The distribution of some trees and shrubs of the
Carolinian Zone of Southern Ontario". In the first of these papers
they noted that a floral "territory" (of trees and shrubs
particulary) formed a unit in eastern North America "From its
northern limit, somewhere in Canada, it stretched into the southland as
far as Tennessee and the Carolinas, and even beyond...Captivated by a
name redolent of the South, one investigator called, quite
appropriately, the last, roughly defined expanse, the Carolinian
Zone". They don't name the romantic investigator but in the final
paper they provide a genealogy of the word starting in 1859 with J.G.
Since the Fox & Soper publications,
the term Carolinian has received wide currency among Canadian authors in
a variety of fields, appearing in papers by Catling et al. (1992), Cody
(1982), Cruise (1969), Maycock and Fahselt (1987) Thaler and Plowright
(1973) and of course Soper (1956 & 1962), to name a few.
At some point the 'redolent' quality of
Carolinian must have struck a resonant chord within the Ontario Dept of
Lands and Forests and the Canadian Parks Service: Pinery and Rondeau
Provincial Parks, and Point Pelee National park began proclaiming 'Deep
South' Carolinian status.
"Carolinian" Really Mean?
What are we to make of this word
Carolinian? Perhaps, like many words, it is evolving; a semantic moving
target, blurred, difficult to define. We could make it a colloquial
scientific term, a kind of ethnocentric artifact; or a description of a
particular community. We could use it as a horticultural term, as a site
description for restorative work, or a "nickname" for the
Deciduous Forest Region. We could let it evolve until some consensus is
As it is we have a term that is
provincial in both senses. Is it reasonable to change terminology at a
political border? Perhaps we should use the term Deciduous Forest Region
(or Beech-Maple Forest) and retain Niagara Section as token chauvinism.
We could reserve Carolinian for communities dominated by the species
commonly used to typify the Carolinian Zone; species which are largely
restricted to well drained, sandy, often acidic, soils.
Many ecologists, such as Dice (1952),
have recognized associations within a biotic province. To quote Dice the
association is "a type of community that in aggregate covers an
important part of the area of a biotic province". Dice's
'association' is essentially synonymous with the mapping units of W.A.
Morsink (1984). Morsink used 5 'Deciduous Forest Mapping Units' for the
forest vegetation of Essex, Kent & Lambton Counties in Ontario.
These included "Carolinian Upland Hardwoods". This contained
Sassafras, Flowering Dogwood, Tuliptree, Black Gum and American Chestnut
as well as Sugar Maple & Beech.
The concept of plant "association" was also recognized by both
Halliday and Rowe. We can add further confusion at this point by noting
that some researchers, of which Maycock is a good example, have
emphasized the futility of defining associations because of the
"continuous characteristics of forest patterns within the Deciduous
What's our preference you will likely ask? Well, we would like to see
Deciduous Forest Region used instead of Carolinian Zone. We would prefer
Carolinian as a label for those associations within the Deciduous Forest
Region in which Sassafras and Tuliptree are dominants. Some Flowering
Dogwood in the understorey would be nice. Such an association would
likely have had a lot of American Chestnut at one time. Co-dominants
would include Black Walnut, Black Oak, White Oak, Red Maple, Pignut
Hickory, and Black Gum. The species common to the association could be
referred to as Carolinian in the nursery trade. By using Carolinian in
this way we may lose some of the romance (and redolency) but just might
gain some precision from conformity. We wouldn't be surprised if you
Adams, J., 1938. The Flora of Canada.
Reprinted from the Canada Year Book 1938. revised in 1945. pp 1-38.
Allen, G.M., P.F.J. Eagles and S.D: Price, 1990. Conserving Carolinian
Canada. University of Waterloo Press. Waterloo Ontario.
Allen, J.A., 1892. The Geographical Distribution of North American
Mammals. Bull. Am. Nat. Hist. 4:199-243.
Braun, L., 1950. Deciduous Forests of Eastern North America. Hafner
Press. New York.
Catling, P.M. V.R. Catling and S.M. McKay-Kuja, 1992. The extent,
floristic, composition and maintenance of the Rice Lake Plains, Ontario,
based on historical records. Can. Field-Nat. 106(1):73-86.
Cody, W.J., 1982. A comparison of the northern limits of distribution of
some vascular plant species found in southern Ontario. Naturaliste Can.
Cooper, J.G., 1859. On the Distribution of the Forests and Trees of
North America, with notes on its Physical Geography. Annual Report of
the Smithsonian Institute 1858.
Cruise, J.E., 1969. A floristic study of
Norfolk County, Ontario. Trans. Roy. Can. Inst. 72:116 pp.
Dice. L.R., 1943. The Biotic Provinces of North America. Univ. Mich.
Press. Ann Arbor, Mich.
Dice. L.R., 1952. Natural Communities. Univ. Mich. Press. Ann Arbor,
Halliday, W., 1937. A Forest Classification for Canada. Forest SeN.
Bull. 89. pp 1-50.
Hills, G.A., 1952. The classification and evaluation of sites for
forestry. Ontario Dept. Lands & Forests. Res. Rep. no 24.
Lamb, L. and G. Rhynard. 1994. Plants
of Carolinian Canada. Federation of Ontario Naturalists.
Macoun, J. and M.O. Malte, 1916. The Flora of Canada. The Canada Year
Book. pp 43-55.
Maycock, P.F., 1963. The phytosociology of the deciduous forests of
extreme southern Ontario. Can. J. Bot. 41 :379-438.
Maycock, P. and D. Fahselt, 1987. An inventory of ecologically
significant natural vegetation in the province of Ontario: I. Essex
County, Can. Field-Nat. 101(3) 474-486.
Merriam. C.H., 1898. Life Zones and Crop Zones of the United States.
U.S. Dept. Agric. Div. Biol. Surv. Bulletin No. 10.
Morsink, W.A., 1984. Deciduous forest mapping units and major tree lists
for the Essex, Kent and Lambton tri-county area of southwestern Ontario.
Ont. Field Biol. 38:17-28.
Rowe, J.S., 1972. Forest Regions of Canada. Canadian Forestry Service.
Pub. No. 1300.
Seasons, 1985. A special issue celebrating Carolinian Canada. vol. 25
no. 2 summer. Federation of Ontario Naturalists
Soper, J.H. and W.S. Fox, 1952. The distribution of some trees and
shrubs of the Carolinian Zone of Southern Ontario. Trans. Roy. Can. Ins.
Soper, J.H. and W.S. Fox, 1953. The distribution of some trees and
shrubs of the Carolinian Zone of Southern Ontario. Part II. Trans. Roy.
Can. Ins. 62:3-32.
Soper, J.H. and W.S. Fox, 1954. The distribution of some trees and
shrubs of the Carolinian Zone of Southern Ontario. Part III. Trans. Roy.
Soper, J.H., 1956. Some families of restricted range in the Carolinian
flora of Canada. Trans. Roy. Can. Soc. 65:69-90.
Soper, J.H., 1962. Some Genera of Restricted Range in the Carolinian
Flora of Canada. Trans. Roy. Can. Ins. 70:3-56.
Thaler G.R. and R.C. Plowright, 1973. An examination of the floristic
zone concept with special reference to the northern limit of the
Carolinian zone in southern Ontario. Can. J. Bot. 51:765-780
Waldron, G. 2003. Trees
of the Carolinian Forest: A Guide to Species, Their Ecology and Uses.
Boston Mills Press, Toronto.
Weaver, J.E. and F.E. Clements, 1938. Plant Ecology. 2nd ed.
McGraw-Hill. New York.
Acknowledgement: Although not
referenced above we acknowledge our debt to R.F. Brady et al. who trod
much of the same ground in their report "Regional Municipality of
Niagara's Environmentally Sensitive Areas". Dept. of Geography,
Brock University, St. Catherines, 1980
Essex Region Conservation Authority, 1993
Ken Colthurst, Forester Gerry Waldron,