A savanna relic: Open-grown oaks at Madison, Wisconsin's Picnic Point
The most common vegetation type in southwestern Wisconsin
was the oak savanna, characterized by large scattered oaks interspersed with
prairie grasses and forbs. This attractive landscape fascinated early explorers
and settlers, who had seen nothing like it in eastern U.S. Because the oaks
were so scattered, their lower branches were not shaded, permitting them to continue
growing. These oaks are potentially long-lived, retaining their large lower
branches as long as they are growing in the open sun.
The tell-tale sign of a former oak savanna today is the
presence of trees with the characteristic open-grown character. Once one realizes
what an open-grown oak looks like, it is easy to spot them, even if they are
now embedded in a dense forest.
It is only a brief walk through the gate and up the hill from
the Picnic Point parking area to reach an area with lots of open-grown oaks. In
the photo here, taken last Sunday, four or five open-grown oaks can be seen.
There are also more on the opposite side of the road.
 |
| Five open-grown oaks can be seen in this photo. They are recognized by the presence of large lower branches, or knobs where branches once grew. |
Unfortunately, the oak closest in the photo has lost many of
its large lower branches. Only their stubs remain. All these open-grown oaks
are surrounded by a dense grove of of smaller trees, not oaks but maples and
other so-called mesophytic species.
What did this area look like when these trees were out in
the open? It is easy to tell what the area was like about 80 years ago (when
Picnic Point was still in private ownership) because we have air photos from 1937
(taken by the U.S. Soil Conservation Service). The first photo below shows the
area where the open-grown oaks are now found, and the second photo shows a wider view to put the area in geographic perspective. The open-grown oaks are obvious.
 |
| Air photo from 1937 of the Picnic Point Entrance Area (See photo below for a wider perspective.) |
With high-accurate GIS measurements, one could probably
relate the trees in the air photo to those still present at the site.
 |
| This fascinating view of the Picnic Point Entrance Area in 1937 may be surprising to those familiar with the area today! |
In comparison, the photo below shows the same area in 2010,
about 73 years later.
 |
| Air photo of the same area in 2010. What happened to the former pasture and all the open-grown oaks? |
In addition to comparing the 1937 and 2010 photos, I have
examined air photos for other dates in between. The open characteristic of the 1937
landscape gradually filled in with woods and other woody vegetation. Bill’s
Woods, which was a “real” woods in 1937, remained mostly the same, but the
savanna area, where the open-grown oaks were so noticeable, gradually became
wooded. In 1990, the open-grown oaks still stood out, probably because the
invading woody vegetation had not “topped out” yet. But in the 2010 photo it is
not possible to see where the open-grown oaks were, or even see where the lane
ran, because the woods is dense.
Before 1937, what kept the savanna open, and why did it then
close in? The standard explanation, which is undoubtedly correct, is the
absence of fire since 1937. Almost certainly this area, as well as most of
Picnic Point, was subject to occasional fire, perhaps annual. It is well
established that “farmers burned their woods”, generally annually, in order to
promote “green-up” of the pasture.
There is a clear fence-line at the bottom of the hill
starting at the gate area. We also know from historic photos that cows were pastured
on Picnic Point, and there is one photo in this exact area that shows a cow. In
1937 the ownership was in the hands of the Young family, which we know from
oral history rode their horses on the Picnic Point lanes. These fields,
close to the Young house site, would have been an ideal location for horses.
On September 4, 1935 there was a major fire at the Young
house, essentially destroying it. Soon after that the Youngs decided not to
rebuild at Picnic Point. Instead, they built a new house in nearby Shorewood
Hills. Shortly thereafter, the Youngs decided to sell their holdings at Picnic
Point, and by 1939 the University had control of the property. This undoubtedly
brought a huge increase in use of Picnic Point. In fact, a caretaker was hired
to oversee the site, and he kept careful records throughout each season of
visitation. (The caretaker’s yearly journals are in the UW-Madison archives.)
It seems reasonable that there has probably been no fire at Picnic Point since the university
acquired the property.
What about the present open-grown oaks? These could be rehabilitated, even without fire, by careful clearing of the
understory woody vegetation. This is what has been done to two handsome
open-grown oaks in the Frautschi Point area. (A trail from the Frautschi Point
parking lot reaches these two oaks.) This sort of clearing is often called “daylighting
the oaks”. Bringing in more light to their large lower branches is a very
beneficial thing, and in many cases can “save” a handsome specimen.
That would be my recommendation for all the open-grown oaks
at the Picnic Point Entrance Area.
Incidentally, these oaks are easier to see now than they
will be in summer, when all their surrounding trees have greened up.
It’s only
a short walk up from the Gate, and well worth the visit!
