Friday, July 30, 2010

Field Check - The Other Half

Well, I only got half way through the field yesterday. In the center of the field is a 70 foot diameter patch of Dwarf Sumac. Left to grow, the sumac would form a shrub 20 to 25 feet high. This would not fit well into the open grassland habitat I’m managing for, so the sumac gets mowed even more often than the rest of the field. Shrubs fit this type of habitat if they are kept short.

Last winter the sumac was cut back to four inch stubble. The sprouts are already over three feet tall and growing rapidly. Dwarf Sumac is the host plant of the Red-Banded Hairstreak, a butterfly species I have yet to see here. Instead of feeding on the green leaves, the larvae are reported to feed on decomposing leaves on the ground at the base of the plant.

Even though it is beginning to look a bit worn, this nest box has produced a lot of birds this year. I’ve attempted to clean it out several times, but each time I check, another nesting is underway.

The sequence has been Bluebird – Bluebird – Tree Swallow and now there are five bluebird eggs being incubated. The nests have been stacked so high there was no room for me to get my camera in for a shot. It’s odd that this box had no nests at all last year.

The ant hills have recovered from the freeze damage that occurred over the winter. This mound never had a chance to develop freeze damage because it was so thoroughly hidden by the Indian Grass last year that I hit it with JR in December. I’ve been watching to see what effect losing the top of the mound had on the health of the colony. Apparently no permanent harm was done in this case.

Many of the late summer bloomers are almost ready to put on a show. This boneset is enormous. You could normally cup the boneset flower head in your two hands. This plant has reached a height of five feet and has produced side branches the entire length of the central stalk. I don’t know if this is a result of being freed from competing with last year’s grass stalks or the weather we’ve had this year or some other factor. Whatever the cause, it’s a great looking plant.

Six weeks ago, this was a mass of Oxeye Daisies. Now all signs of that exotic invader have disappeared and native coneflowers have taken the dominant position. The trick will be phasing out the invaders while increasing the natives.

You can’t go more than 100 feet across the field without walking into a different vegetative mix. Each mix produces its own shade of color. Each vegetative block will eventually produce its own mix of animals, primarily insects, that are dependent on the plants found in that particular mix. Each year, the blocks become more distinct.

The diversity found across the field, continues into each individual block. Species diversity in each block is increasing as new plants with similar needs, join the mix.

It’s hard to identify all of the factors that influence development of the various blocks. Position on the landscape such as hilltop, side slope or swale definitely plays a role. Soil type, depth to bedrock, type of bedrock, effects of past farming practices and aspect also provide a strong influence. The result is an almost infinite range of possibilities. Each different combination produces a different mix of plants and an endless supply of interesting things to discover on my walks.

This is a look back the way I came. I’m quite satisfied with the way the field is responding to being mowed during the winter. Encroaching shrubs were severely reduced and those that were left are really being stressed as they become overtopped by the rapidly growing grass. Now I can stand back and watch the tall grass grow.

1 comment:

  1. These "field check" posts are fascinating--and your field is gorgeous. Even in a dry year, you get more precipitation than we do, and it's so beautiful, with all those classic prairie plants. I have serious prairie envy for someone whose big bluestem is covering a whole "dry" slope and can reach 10 feet. At least we have a little, now, but here it strongly prefers the damper sites.