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| Tom's Blog
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| 2/23/2008 | Snow Shoeing at Pleasant Valley Conservancy The weather is slowly turning favorable and today was a nice sunny day (34 F). Kathie, Susan, and I put on the snow shoes and toured the Conservancy.
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| 2/21/2008 | Seed Germination Tests I have been doing seed germination tests the last few years. These are important when one is dealing with hand-collected seeds. Purchased seeds always come with a viability test conducted by the vendor, but when we collect our own seed we need to have our own tests. We could have these done by the seed laborarory operated by the Wisconsin Crop Improvement Association, but these cost money (upwards of $20 per test). Since I don't need the "certification" that the seed lab provides, I have been doing these tests myself. The procedure for these tests is fairly simple. All you need is some covered flat plastic or glass dishes and some paper towelling. (I use plastic petri plates.) The towelling is moistened (and kept moist throughout the days of the test) and the seeds are laid down. The dishes are wrapped to keep them from drying out and placed in a refrigerator (4 C; 40 F) for a month or two. This cold moist treatment is essential to break the dormancy of the seeds. (Grasses and some other species do not need this cold moist treatment but most forbs do.) This treatment is called "stratification", and mimics what the seeds experience in their natural state. After stratification, the dishes are unwrapped and placed under lights in a warm place (20-30 C). I use banks of fluorescent lights controlled by a timer, giving the seeds 16 hours light and 8 hours dark. Again, this mimics conditions in nature. The seeds are checked every day to be sure they are still moist. If they are dry, the paper towels are remoistened. Within three or four days, a few seeds may show signs of growth. Usually the root is visible first, followed by the cotyledons. I make notes each day for the first two weeks, then continue observing every few days for the next month. With "good" seeds, the germination percentage may be as high as 50-70%, in some cases even higher. Other species may show lower viability, or none at all. We have found certain species take a long time to germinate, sometimes even a year or more. In those cases, we sew the seeds in potting soil in a flat and put them out doors, monitoring every week or so. Some species have special requirements for germination, such as warm moist stratification, and some require even more complicated strategies. See these references, or do an internet search for the species you are interested in. (The New England Wild Flower Society guide to growing and propagating wildflowers of the United States and Canada by William Cullina. Seed germination, theory and practice by Norman C. Deno.) My main interest has been in endangered or threatened species, of which purple milkweed (Asclepias purpurascens) is the most important at Pleasant Valley. I have found that the milkweeds show rather high viability rates, usually over 50% and sometimes higher. The photos below show a typical result after two weeks incubation.
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| 2/20/2008 | Collections at the UW-Madison Herbarium from Pleasant Valley Conservancy The University of Wisconsin-Madison Herbarium is a priceless repository of the Wisconsin flora. It contains around 1,000,000 specimens, which include the world's largest collection of Wisconsin plants. Although this is a museum of "just" dried specimens, each specimen sheet contains important geographic and botanical information. The Herbarium is housed on the first floor of Birge Hall. Among other things, the Herbarium has an outstanding web site where information on its collections can be obtained. One can do a search by common or Latin name, collector, or location. Many specimens contain surveyor's coordinates so that one can focus in on the flora of a specific area. We have deposited a number of unusual or interesting specimens from Pleasant Valley Conservancy. Some of these were done by Kathie or me, but a lot of them were done by two individuals we hired, Brian Huberty and Joshua Sulman. Brian's collections focussed on species we have that are less common in Wisconsin. Josh Sulman's collections dealt mostly with sedges and grasses, and with plants from the wetland. In a recent search using "Pleasant Valley Conservancy" as the search term, I found about 50 specimens. This is not the complete total, because not all deposits included the Pleasant Valley Conservancy location. A search using the Town/Range/Section numbers (T7N, R6E, Section 5) brought up a few other collections, including some made along County F many years ago. It is encouraging to know that the specimens we deposited will remain permanently in the Herbarium. As such, they join those made by 19th and 20th century collectors, which include some distinguished plant taxonomists such as N.C. Fassett, Hugh Iltis, Ted Cochrane, Floyd Swink, and Merel Black. |
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| 2/18/2008 | Life on the Edge On our way back from Florida we stopped at a very interesting natural area southeast of Atlanta, Georgia. In that area there are quite a few huge granite blocks forming small mountains. Stone Mountain, Georgia, is the most famous, but that is a tourist trap. We visited Davidson-Arabia Mountain Nature Preserve, which is part of a Dekalb County Park and well taken care of. There are 2000 acres of granite outcrop, wetlands, pine and oak forests, etc. in this area. See http://www.arabiaalliance.org/ for details. I was attracted to this interesting habitat because of my extensive work in extreme environments in Yellowstone National Park and other thermal areas. You learn a lot about ecology by observing how living organisms cope with extreme habitats. The huge granite mountains here provide great challenges for plant life. The rock is very resistant to erosion and soil formation is sparse. Small depressions formed in the granite provide the only habitat and the plants that develop are unusual. Two Federally protected plant species are present, as well as several other endemic plants. One of these endemic plants is Small's Stonecrop (Diamorpha smallii), which forms brilliant red patches. It is a succulent plant related to sedum and is called a winter annual. It overwinters as a fleshy succulent (see photo below), forms white flowers in April, and sets seed before the end of May. During the intense sunlight and heat of a Georgia summer the seeds remain dormant. The seeds germinate in the fall and form the red vegetative growth again. Another endemic is an oak, Quercus georgiana, found only in Georgia and parts of Alabama and South Carolina. It grows on dry granite and sandstone outcrops of mountain slopes. Broomsedge (Andropogon virginicus), a grass related to our big bluestem, is also present, along with a number of broadleaf species. The photos below give some idea of this interesting habitat.
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| 2/16/2008 | Some Florida Prairies and Savannas We are familiar with maps showing the distribution of prairies and savannas across the middle of North Ameria. The most common is Transeau's Prairie Peninsula map, which shows prairie dominant in the Great Plains, Illinois, and southern Wisconsin, with "fingers" extending into Indiana and a few outliers in Ohio and Kentucky. Such maps give the impression that "prairie" is a Midwestern phenomenon. Perhaps, but there is lots of prairie, and even savanna, in Florida! The Florida prairies and savannas are fire controlled ecosystems. They have been there a long time. Botanist William Bartram described them in the late 1700s, attributing them to the penchant of the Native Americans for burning. Although many of the prairies and savannas in Florida are the result of prescribed burns, lots of natural fires also occur. In fact, Florida has one of the highest frequencies of lightning-caused fires in the U.S. According to the Florida Native Plant Society, most lightning-caused fires occur early in the rainy season before vegetation and soils are well hydrated. They burn across broad areas, and create favorable conditions for the growth of many native plants. Florida's prairies once spanned the state, stretching virtually from coast to coast at the level of Orlando, with an area estimated at 300,000 acres. One area we visited that had some nice prairies was Ocala National Forest, which is a bit south of the city of Gainesville. Most of the prairies here were wet prairies, developing in depressions where water can accumulate at certain times of the year. I assume that it is the high moisture that keeps the trees and shrubs out. The first photo below shows one of these. The second photo shows a savanna-like area that has developed in the central sandy area of Ocala National Forest. Both of these areas had been burned within the last year or two.
Although these areas do not look much different than our prairies, the species are completely different. Among the grasses are wiregrass (Aristida stricta), broomsedge (Andropogon virginicus), and Florida threeawn grass (Aristida rhizomophora). The forbs also are quite different. Another area we visited was Apalachicola National Forest, a huge tract of land sandwiched between Tallahassee and the Gulf of Mexico. Prescribed burns are used extensively here also. We were able to drive over paved and dirt roads for many miles, coming on recently burned areas, and areas that had been burned in the last several years. There are no private residences, except for very rare inholdings. One can walk anywhere. One area that I was interested in was a "savanna" area on the west side of the forest (near the settlement of Sumatra). The savannas here were predominantly in wet areas. The photo below shows a typical example.
No open grown oaks in this savanna! Walking around was a little tricky, as despite the relatively dry area, there was water everywhere. Slight depressions had standing water, but even the slightly raised ground felt soft and mushy. Again, these areas are frequently burned. The pines here are either longleaf pine (Pinus paustris) or slash pine (Pinus ellottii). These are fascinating areas, and deserve more detailed study. Maybe next year!
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| 2/16/2008 | Longleaf Pine Burn We were in Florida when quite a few prescribed burns were going on. They were easy to find from the smoke, or from the signs along the road. We happened upon the one pictured here soon after it was finished. It was along US 98 a few miles from the village of Panacea. Things were still smoking. We were able to drive along the fire breaks on dirt roads and see the extent of the burn. I used my odometer to measure the size: 260 acres. A large burn for Wisconsin but routine for Florida! Across the fire break was an unburned unit that looked very similar. The comparison below of these two photos is interesting.
The fuel here is a mixture of grasses, pine needles, leaf litter, and shrubs. The saw palmetto's in the foreground seem to burn fairly well, although I suspect they resprout readily from underground buds. It is easy to see why it is essential to burn often in Florida. With the long growing season and humid (summertime) climate, things grow fast! The sign shown below is an indication that Florida thinks prescribed burns are important. This one was erected by the Florida Forestry Commission. The photo on the right shows some small longleaf pine saplings. This species is the principal pine in the southeast coastal forests. It is noteworthy for its resistance to fire.
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| 2/16/2008 | Tall Timbers Research Station During our recent visit to southeastern United States we visited Tall Timbers Research Station, a famous institution that has been a pioneer in promoting the use of prescribed burn for obtaining healthy forests. Tall Timbers is now 50 years old, and continues its research and advocacy in a vigorous manner. It is located in northern Florida just over the Georgia line. This area is prime habitat for longleaf pine, a fire-dependent species that covers vast acreages in the coastal southeast. Tall Timbers began with the work of Herbert Stoddard, who was a pioneer researcher on bobwhite quail. In the 1920s Stoddard was hired from the Milwaukee Public Museum by the U.S. Biological Survey to find out why the quail populations in the southeast had undergone a marked decline in numbers. Quail are highly prized by upland bird hunters, but the longleaf pine habitat must be burned to maintain hits health. Tall Timbers was the estate of Henry Beadel, a wealthy architect who was also a passionate quail hunter. The longleaf pine ecosystem had always been burned by landowners, usually on an annual basis, but in the 1920s the U.S. Forest Service convinced property owners in the southeast to stop these burns. Beadel complied but soon noticed that his land became choked with underbrush and the quail population markedly declined. He joined with other landowners in the area to induced the U.S. Biological Survey to hire Stoddard. Through the years after this, Beadel along with Stoddard and his assistant Edward Komarek continued scientific experiments on land and wildlife management. In 1963 the Tall Timbers Research Station was established on Beadel's property. The Fire Ecology Research Conferences, begun at that time, are priceless documents of the importance of prescribed burns, not only in the southeast, but throughout the country. Due to its significant role in promoting fire ecology, the Tall Timbers estate was listed in 1989 in the National Register of Historic Places. In the next post, I will give some of our discoveries of the longleaf pine ecosystem and its fire ecology.
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