Pleasant Valley
Conservancy |
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| Our spring begins with major controlled burns. Once
burns are finished, we begin hand-planting seed in some of the burned
areas. While hand planting, we keep an eye out for what is growing
and flowering. We also enjoy bird watching, especially in our wetlands.
Spring is one of the busiest but also greatest times of the year
at Pleasant Valley Conservancy. |
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Early
spring flora |
| Timing of the spring depends on the weather, and our
spring weather is nothing if not unpredictable. This spring we had
unusually warm weather from mid-March through mid-April (great for
controlled burns, see below), and the early flora was really special
this year. Because the south slope warms up early, we had fantastic
displays of color |
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The whole south slope, approximately 30 acres, was
covered with violet wood sorrel (Oxalis violacea). Folks
driving along Pleasant Valley Road stopped to ask what the color
was due to. Violet wood sorrel is one of those species that is almost
impossible to plant, since collecting seed is really difficult (seed
pods mature and dehisce almost immediately). Due to extensive removal
of undesirable woody vegetation and yearly controlled burns, we
have created a habitat where this attractive species propagates
itself! |
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| Another early spring species is bird's-foot violet
(Viola pedata), which is very prolific in the original
"goat" prairie on the Conservancy, but is also widely
distributed throughout the south-facing slope. This year the blue
carpet of this characteristic dry-prairie violet was especially
nice. |
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Savanna flowers Two attractive
species that flower early in our savannas are early buttercup
(Ranunculus fascicularis) and wood anemone (Anemone
quinquefolia). They are small but pretty. Since we started
clearing undesirable brush from our oak savannas, these two species
have proliferated well and can be found here and there throughout
the Conservancy. Wood anemone in particular grows in patches,
sometimes of fairly large extent. |
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Controlled burns |
Controlled burns are a key management tool and
we spend quite a bit of time organizing and carrying out these
burns. Our burn season actually starts in late
fall, when we do most of our savanna burns, but resumes again
in early spring. Weather is a critical factor in determining what
burns we are able to carry out. Fortunately, spring 2005 had good
burn weather.
We had two large burns and several smaller ones, all successful.
The map below shows the areas burned
in fall 2004 as well as spring 2005. In addition, the U.S. Fish
and Wildlife Service carried out a very large burn of the Pleasant
Valley/East Blue Mounds Creek wetland. This burn involved not
only Pleasant Valley Conservancy wetland, but wetland of several
other property owners in the Valley. Details
of the U.S.F.W.S. burn. |
| Tutorial on prescribed
burns |
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South slope burn. Because the south slope warms
up quickly from the sun, snow does not remain long. The spring
had been cold and snowy and there had some wet snow about 2 weeks
earlier. Although this snow quickly disappeared on the south slope,
snow still persisted on northern exposures. The day of the burn
we had sunny weather with temperatures in the mid 60s and low
relative humdity. Wind was gusty varying from 7-18 mph from the
south east.
The principal fuel on the south slope is little blue stem grass
on the lower slopes and oak leaves up among the savanna.
We had spent quite a bit of time in the two days before the burn
clearing around birches and standing dead trees, since they are
fire-sensitive and provide problems on mop-up after the burn.
A crew of 10 people participated in the burn. We started the
burn on the upper NW ridge (downwind) and allowed the fire to
back down the ridge almost to the middle of the slope. Another
crew did a back burn from the middle of the ridge to the east
end. Thus, most of the upper slopes had been blackened before
the major head fire was started. Even so, lower branches of quite
a few trees caught fire due to the gusty wind. Lots of downed
timber burned as well. We spent all afternoon putting out burning
wood.
It was a very successful burn, with essentially 100% coverage.
Quite a contrast with the first year we burned this slope (1998)
when the coverage was about 30%!
Because of the low humidity and wind, the burn went very quickly,
and the whole slope, 25-30 acres, was burned in a little over
an hour.
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Prairie/savanna burn Our second major burn
involved our two planted prairies (Pocket and Toby's) and the
woods/savannas near them (Units 13, 17, 20, and 21 on the map
below). In contrast to the south slope burn, which could be
done as one large unit, the second burn involved a number of
small separate burns. These combined burns took all day, and
we were doing mop-up almost until dark.
We had a crew of 9 experienced people. There had been a bit
of rain two days before, and although the weather had turned
sunny, the morning of the burn was cool. There was a lot of
dew and we had to wait until almost 11:15 AM before we could
start lighting. However, the humidity was low and by 12:30 PM
conditions were quite favorable.
Toby's Prairie is our principal source of Indian grass for
seed collecting, and burning strongly stimulates seed set. However,
it had been burned for five years in a row and we thought part
of it deserved a rest. Since Toby's Prairie is essentially two
units divided by a lane in the middle, we burned only the north
unit. We made good use of the pumper unit on our Kubota tractor
in this critical job.
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Unit 13, a fine white oak savanna/woods, burned very well, with
virtually 100% cover. The burn on the other savannas, Units 20
and 21, was more spotty due to the fact that these units had only
been cleared a year before and had a large black walnut population.
This tree species produces a toxin, juglone, which inhibits many
native species of forbs, and the fuel supply was poor in parts.
Only about 50% of these two units burned well. |
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Wetland burn by
the U.S. Fish and Wildlife Service
On April 30, 2005, a major controlled burn was carried out on
the wetland in Pleasant Valley and the adjacent East Blue Mounds
Creek. This burn was managed by the U.S. Fish and Wildlife Service,
with participation of The Nature Conservancy. Mike Engel from
the U.S.F.W.S. wrote the burn plan and coordinated the whole burn,
and Hannah Spaul coordinated TNC's participation.
The wetland had multiple ownerships, and all owners gracefully
agreed to permit their portion of the wetland to be burned. The
total area was approximately 140 acres; the perimeter was about
3 miles in circumference.
U.S.F.W.S. provided most of the equipment and crew. The burn
plan was a detailed 18-page document which covered all contingencies.
The weather remained favorable throughout the burn, although some
traffic control on the surrounding roads was necessary because
of reduced visibility due to smoke.
Personnel assembled at about 9:30 AM and the burn ended about
5 PM.
A survey the following day determined that at least 50% of the
wetland burned, although some areas burned close to 100% and others
burned considerably less than 50%. Sedge meadow burned much better
than cattails. Wherever ground water was at the surface, burn
efficiency was low. Vegetation in areas with springs or open water
did not burn.
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| The wetland burned moderately well. Areas that did
not burn were had high groundwater and were wet. Numerous springs
and seeps arise in the wetland, and favor the growth of water-loving
plants. Marsh marigold (Caltha palustris) grows very well
here and these areas did not burn. Most of the cattail areas also
did not burn, although a few did. Sedge meadow and wetland grass
(including reed canary grass that lines East Blue Mounds Creek)
burned very well. The map below, and the photos here,
taken two days later, show the extent of the burn. The photo to
the right shows the two creeks, Pleasant Valley Creek at left, and
East Blue Mounds Creek at right. (Blue Mounds State Park is the
high hill in the distance.). This photo, looking south, should be
compared with the map below. |
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| Right. Close-up along East Blue Mounds Creek. This
is one of the few high-reed-canary-grass areas in this wetland.
As seen, it burned very well. |
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