Please
click here to return to main page
Survey
of Edge Effect of a Clear Cut Forest
Miles Robinson, Pam Norton, Karen Aleman, Matt Hayes, Bob Burtch, Carmen Nunez, Ron Hellstern
To survey the impact of the cut forest on the forest proper we evaluated several features of the plants along a transect that ran from the cut area, five meters into the forest cut designated at –5m, back into the forest for 50 meters on a line set at 290 degrees. Sampling and measurements were taken at negative five, zero (at the edge of the forest and the cut), 10 meters, 20 meters and 50 meters into the forest. Ground level plant cover and photosynthetic cover at chest heights was determined for a two meter square, one square meter on each side of the transect. In addition the diameter of any woody species of plant within four square meters of the sampling points were taken. Samples of plants at each point were taken back to the lab for identification.
|
Location
in meters |
%of
ground coverage |
% of
foliage cover at 1.3m |
D.B.H.
in cm |
D.B.H.
Plant Type |
|
-5 |
7 |
100 |
0 |
|
|
0 |
40 |
80 |
|
|
|
10 |
2 |
40 |
4.6 |
pentaclethrea,
cyclanthaceae, unidentified broad leafed woody stem |
|
20 |
2 |
55 |
5.5 |
rubiacae, |
|
50 |
1 |
15 |
5.9 |
papilionaceae |
Protocol
for measurements:
The ground cover at ground level was determined by moving aside any of the top material right down to the level of the ground. The amount of green, growing plant material actually covering the ground was then estimated in the two square meters and recorded as a percent coverage.
Chest height photosynthetic (foliage) covering was done by view from chest height (approximately 1.3m), the ground that was visible and recording the observation as a percent of visible covering.
Using a two-meter string any woody plant found in the sample area was measured at chest height.
Samples of plants within the two-meter square area of the sample areas was taken to identify for a general picture of the plants at each sample area. The trees that were measured also had samples taken so they could be identified.
Conclusion
As we moved into the forest ground cover decreased slightly. There was a dramatic drop in the amount of photosynthetic cover from the cut forest into the forest proper. We were surprised to see the lack of ground cover as the photosynthetic cover was 100 %. Our data on species diversity showed a decrease from the cut forest at –5m to the inside of the forest at 50m . Measurements of dbh in the cut forest were nonexistent as there were no trees present. Measurements of dbh along the transect line progressing further into the forest gradually increased. This increase was very modest as there were few trees along the transect line. This small sample size may not be representative of the entire forest. Further study is needed.
Footnote: Since starting point “0” was in the midst of a manmade trail, we took our sampling of plants to the right of the transect line to include plants at the edge.