Home

Archive

8/06
9/06
10/06
1/07
4/07
5/07
6/07
7/07
9/07
10/07
11/07

 

Tom's Journal (Blog)

 

Setting Up a Tree Database

One of the tasks we have set for ourselves this winter is to construct a database of our savanna trees. We are using a Garmin global positioning system to locate each tree. At the moment we are marking every tree greater than 4 inches in diameter. (We may increase this to 6 inches if we have to deal with too many small trees.) The photos show this task under way. A Waypoint is set for each tree, and the coordinates recorded, also the altitude. Each tree is permanently marked with a 1 1/4" aluminum numbered disk. In addition to diameter and the GPS coordinates, the species is recorded, and any other items of note. If the tree is dead, this is also recorded. Each day's data are uploaded to a computer and converted to an Excel file. The goal is to prepare a detailed map of the savanna trees. In past years, we have lost a few trees each year from windthrow. By having our trees permanently marked, we will be able to obtain useful information about this phenomenon. I'm not sure how long this project will take, but we have all winter, and can carry out this work when there is too much snow for useful brushcutting. It is hard to know how useful this database will be, but I have hopes that once we have it, we will find lots of applications..

 

Using GPS to Locate Bedrock Strata

Today I was testing a new GPS unit that I bought primarily for database uses. However, it had a good altitude readout, which made it possible for me to locate the boundaries of the various bedrock strata. If you refer to the geology page, there is a cross section of Pleasant Valley Conservancy drawn by Prof. Emeritus Bob Dott, who is the expert on Dane County bedrock geology. That cross section shows the locations of two dolomite layers, one at the top of the ridge, and a smaller one (the Black Earth Dolomite) about half-way down. The erosion resistance of the smaller one leads to the formation of a shelf-like layer about half way up the hill, which I call the "dolomite shelf".

There are ecological consequences here, as there are wet mesic plant species that can be found on the "shelf", a long way from the wetlands which they prefer. I assume that there is water seepage at the base of this dolomite which provides suitable habitat for the wet mesic species. The species found here are ironweed (Vernonia fasciculata), culver's root (Veronicastrum virginiana), and sweet Indian plantain (Hasteola suaveolens)

Because this layer runs level across the Conservancy, whereas the gullies and other erosional features modify its appearance, I have wanted to be able locate it in areas where its appearance is not so obvious. My new GPS unit is accurate enough to do this. I did some preliminary work today while snowshoeing and was pleased to see that I could get the data I need.

The photo below shows an area in the middle of our White Oak Savanna where we had constructed a fire break. The reason we constructed the fire break there was that the topography was fairly level there. The reason it is more level, my GPS tells me, is that this is where the Black Earth Dolomite is located. With the snow, this fire break stands out much better than it does in the summer. In fact, I can look across the basin and spot exactly where the dolomite layer is located.

Next spring I plan to put in some survey stakes along the whole length of the dolomite layer, and then do some more careful plant identifications along that route.

 

Finally Out in the Field (Snow)

The weather finally moderated enough so that Kathie and I were able to get out in the field. It was a good chance to use the new snow shoes that have been sitting in the closet for the past several winters, waiting from the right kind of conditions. The day started out sunny but then turned cloudy, but there was no wind and we had a nice time.

 

 

Getting Ready to Raise Seedlings

The weather is not any better; it's worse in fact. So we are starting our greenhouse work early this year.

We are rasing in the greenhouse seedlings of quite a few unusual, less common, or special concern species. These will be transplanted outdoors next May. The commercial people call these small plants "plugs".

This is the third year we have raised plugs in the greenhouse. The last two years were quite successful, so we anticipate another good year. There are some advantages to raising your own plants. First, they are lots cheaper. The commercial prices this year range from $2 to $6 a plant. Second, there are no commercial sources for plugs of many of the things we raise, such as Lespedeza leptostachya (Endangered in Wisconsin). Third, we can probably raise healthier plugs, since we can watch over them better, and adjust the conditions for each species.

Since the seeds of all the species we raise need a cold period before they will germinate, starting now makes a lot of sense. We plant the seeds in trays of moist potting soil mix and place them in a cold room at 4 C for a month or so. We will bring them out into the greenhouse around the first of March, transplant to pots around the first of April, harden them outdoors in early May, and transplant to Pleasant Valley Conservancy in late May.

Then we water them carefully as needed all summer.

The last two years we have set out around 300 plants of about 25 species. Our success rate has been about 70%, which we think is pretty good, especially with the drought conditions we had in mid-summer the past few years.

It was great working in the greenhouse headhouse today. Snow was falling outside, but inside we were in shirtsleeves. There is nothing like a greenhouse in winter time!

What do you do when the weather is bad?

The first of December the weather turned really bad. Snow/sleet/and ice made a hard crust and then 6 inches of real snow came down on top. It was almost impossible to stand up in the field, especially on our hills. Our plans for brush cutting had to be cancelled. Hopefully, we will get a thaw and we will be able to get back to this kind of work.

In the meantime, we are starting our data entry work. All of my notes from 2007 need to get computerized. These are primarily observations of plant species growth, flowering, seed set, etc., throughout Pleasant Valley Conservancy. I record these data frequently. I have been doing this for the past five years, and the records provide a great view of what has been happening in different parts of the Conservancy. In addition, they provide an excellent phenological record.

These are all recorded in Excel spreadsheets, and a given year usually has 6000-8000 lines of data. We use a lookup table routine that uses a six letter code for each species (for instance, Echinacea pallida is Echpal). The lookup table contains the Latin and common name of each species. Other columns include month and day, the Management Unit number, and observations on flowering etc. Type the six letter code and press F9 and the next two columns are filled in. Then record the date, Unit number, and detailed observations.

Last year I took all five years of data (2002-2006) and merged them into one big file, and then created a variety of reports. For instance, the list of species for each Unit, plus lists for various types of habitat (prairie, savanna, etc.)

It takes quite a while to computerize all these data, but it makes good work when the weather is bad.