So we know that adding midges to plots in areas where there normally are none changes the plant community from a heathland to a grassland and increases overall productivity - but what exactly is it about the midges that causes this change? The most obvious answer is that the midges add nutrients that are limiting in the soil, which in this case would most likely be nitrogen. To test this, we've set up plots in a variety of communities and are adding a nitrogen fertilizer to observe the effects. If we see the same results as we got when adding midges, then nitrogen in the midges is probably what is causing the community changes.
Yesterday we drove out to all the plots to apply a round of fertilizer and to take baseline measurements of all of the sites. This involved cataloging the plants encompassed within the plots as well as those in the site, measuring the amount of light that reaches the ground through the plant canopy (which correlates to plant biomass), and taking soil samples. This means I had a crash course in Icelandic plants and am now an expert in identifying them!
 |
| Tea Leaf Willow (Salix lanata) |
 |
| Heather (Calluna vulgaris) |
 |
| Bear berry (Arctostaphylos uva-ursi) |
 |
| Moss campion (Silene acaulis) |
Yes, I know the scientific names as well.
The coolest plot by far is in the lava field:
And we saw some impressive midge columns! Actually I got engulfed in a midge column, possibly because we had just learned that you can attracted midges by humming at a certain frequency. I'm not sure if someone actually hit that frequency or if there were just a lot of midges in the plants we were rustling up while fertilizing.
Personally, I think a certain frequency that repels midges would be much more useful.
No comments:
Post a Comment