Friday, July 2, 2010

Transition Zone

I’ve identified another area for the Maintenance Area portion of my updated management plan. I think of this as a transition zone between the open field and the closed forest. This rocky, shallow soil area is located on a south facing slope where it spends much of the year baking in the sun. Invasive plants are very rare on this site, so it should be a good area to clean up and monitor arrival of any new invasives.

Seedlings of Ash and other deciduous trees remain in a stunted condition because of lack of light. Is the ground cover staging to develop into full forest if given the chance? In any situation, there are always plants that persist in diminutive specimens, waiting for conditions to become favorable for their growth and dominance. On this site there are also grassland species in the same waiting mode as the trees. Both are waiting for the same thing – sunlight.

It doesn’t look like anything special, but I think there are important lessons to learn here about persistence of seeds and plants in a changing environment. Changes in sunlight levels cause changes in the health and vigor of the plants. A sudden increase in light levels, such as might occur as the result of clearing activities, can often trigger an immediate, dramatic change in the visible plant populations. The timing and amount of newly available sunlight would dictate which group of plants dominates in a new regime.

I’ve often wondered how species that were not present on a site could suddenly become a dominant species in the mix. Some people attribute the sudden appearance of previously unseen plants to seeds germinating from a persistent soil seed bank. Studies of seed viability under various conditions suggest that the seed of most species does not survive for long periods in the soil. Even if these new plants are coming from seeds, how can a species that takes several years to reach flowering age, be present and blooming a year after the site is exposed to sunlight. I believe that many species persist in the shade as small, poorly expressed individuals that are overlooked in a typical inventory. Sunlight gives them the ability to quickly transform into robust specimens. These transition zones will make an excellent place to discover what some of those plants look like when in bare minimum survival mode.

There are many of these transitional zones at Blue Jay Barrens, but this seems to have the greatest flora diversity and also contains my lone Yellow Lady’s Slipper Orchid. The seed pod is still looking healthy and has not lost its assassin bug guardian. As far as I can tell, the bug has never left the pod. I wonder what type of insects it has been capturing.


  1. My Yellow Lady slipper pods have disappeared...I have been watching it and suddenly it is gone!!!

  2. That is so cool how the assassin bug is still present and on the job! Who'd have thought?

  3. grammie g - Isn't it aggravating when plants disappear? Several years ago I was looking at a fern I had never seen before. I went back to the house to get my fern book and then went right out to check the fern against the descriptions. I couldn’t find the plant again. I knew I was looking in the right spot and finally I found just a little bit of the stem that was left. In a matter of 20 minutes, something had come by and eaten that fern. I decided later than touching a plant with your fingers makes it more likely to be eaten by a deer. Now I always use a stick to move flowers or turn over leaves. But even plants that don’t get touched can end up as meals for the local herbivores.

    Karen - I was amazed to find the assassin bug still on the seed pod. I’m wondering how big it will get before moving off to better hunting grounds.

  4. the deer are ruining almost all of my plants no matter how hard i try to keep them away they keep coming back for more they ate almost all of my stag-horn sumac plants/trees they ate all the leaves off my hickory nut tree its a small tree they ate my small walnut tree i just planted and i don't know what the hell to do now