Phenology Project: Lineage Mapping

One final component of my phenology project assignment is to do what my professor calls “lineage mapping” of our site – to create a map or other representation of its natural features, land use history, etc. As a reminder, here is where I am in Wisconsin, way up on the border with the UP (image from Google Earth).

Drainage Basin

This map uses images and data from the Wisconsin DNR’s GIS website, WebView. I added a red star to mark the approximate location of my phenology site. When a drop of water falls here, it eventually ends up in Lake Superior. However, I’m just a stone’s throw from the Mississippi River Drainage Basin – as you can see, it starts just beyond the eastern shore of the nearby lakes. (Yes, this is an odd quirk of topography, considering the Mississippi River is west of here.) Because this is Wisconsin data, it stops at the state line; the northern part of this map is Michigan.

Current Habitat Types

Now let’s look at the current habitat types around my site. This is another, more zoomed-in image from Google. The dotted line cutting through at a diagonal is the Wisconsin/Michigan state line. Again, I added a red star to show the approximate location of my phenology spot, and I also added the colored hashing to indicate the habitat types; this website was helpful in determining the type of forest that’s present. Click to view full size.

Past Land Use

That’s what’s here now, but what did this land look like in the past? This part isn’t so much a map as it is a detective investigation! I used information from Tom Wessels’s essay “Reading the Landscape’s History,” from the Orion Society publication Into the Field: A Guide to Locally Focused Teaching, to look for clues about this history of the forest around my phenology spot. Unsurprisingly, it appears to have been logged at some point in its history. In addition to old, large cut stumps…

…I also found a number of trees with multiple trunks, indicating they may have grown as sprouts from cut stumps themselves. The first is a hemlock, the second a sugar maple.

There’s no evidence that this land was farmed after being logged, though. I didn’t find anything that looked like a “pasture tree,” that is, wide, low-branching trees whose shape indicates they grew in the open, having been left to shade livestock when most of the original trees were cleared. (I’ve seen trees like this in other forests – huge, old, spreading oaks surrounded by second-growth forest. Just not here.) In addition to not having been used for pasture, this land must not have been plowed either, because if it had I wouldn’t have seen this.

See those humps of earth? The forest floor all looks like this. It’s called “pillow and cradle topography,” and result when trees fall with their roots intact (rather than being cut), tearing up the soil and creating humps and depressions that can persist for hundreds of years. This topography is the legacy of the original old-growth forest on this site, and if the land had been plowed we wouldn’t see it. The growing season here is so short that the only commercial crop grown in this area today is cranberries.

Future Changes

I’ve covered the past and the present. What changes might my site see in the future? The Wisconsin Initiative on Climate Change Impacts (WICCI) has created a series of maps projecting how the climate in different areas of the state might change in the coming decades. The full set of maps can be viewed here; below as an example is the one showing projected changes in annual average temperature.

Based on these maps, by 2055 my site is likely to see…

  • A 7°F increase in average annual temperature
  • A 6.5°F increase in average spring temperature
  • A 6°F increase in average summer temperature
  • A 6.5°F increase in average fall temperature
  • An 8°F (!) increase in average winter temperature – we’ve certainly had mild weather so far this fall and winter
  • An 0.5″ increase in average winter precipitation
  • An average of 2.5 more extreme precipitation incidents (more than 2″) per decade – actually we’ve been in a drought of late, we could use some more of these right now
  • 14 more days each year when the temperature hits 90°F, more than triple what we typically get now – when I moved here in July the area was in the midst of a genuine heat wave

The climate here will ultimately be more like that currently experienced by the more southern Great Lakes states – my home state of Ohio, for one. The semi-boreal communities that exist here now will probably retreat further north. Sorry to end this on a downer, but it is what it is.

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