 |
|
 |
|
|
Biomass Estimates for Dominant Tree Species
The tree species with the greatest amount of biomass on the Saltonstall ridge are american beech, white oak, sugar maple, white ash, hickory, and black oak.
|
Saltonstall Ridge |
1991 (Mg/ha) |
1999 (Mg/ha) |
Net % Change |
% of 1991 Total Biomass |
% of 1999 Total Biomass |
|
Fagus grandifolia |
13.40 |
9.41 |
-30% |
10% |
6% |
|
Quercus alba |
13.57 |
12.83 |
-5% |
10% |
8% |
|
Acer sacchrum |
37.25 |
51.11 |
37% |
28% |
34% |
|
Fraxinus americana |
19.33 |
21.82 |
13% |
15% |
14% |
|
Carya spp |
20.32 |
24.80 |
10% |
14% |
11% |
|
Quercus velutina |
1.32 |
9.57 |
625% |
1% |
6% |
|
Hubbard Brook |
1997 (Mg/ha) |
% of 1997 Total Biomass |
|
Acer sacchrum |
71 |
36% |
|
Fagus grandifolia |
62 |
32% |
|
Betula lenta |
40 |
21% |
|
|
The tables above illustrate the comparitive biomass of the dominant tree species found on our site. From the data it can be seen that sugar maple comprises the largest amount of biomass on the ridge in both 1991 and 1999. White ash is in second place. The biomass production of american beech seems to be decreasing on the ridge, possibly because the site is draughty. |
|
The data for the hickory and oak species is suspect because it appears there was a difference in how the species were classified in the two years. For instance, black oak (Quercus velutina) production was significantly higher in 1999 but it is not clear why this is the case. We believe that the black oak may have been misidentified or confused with the white oak species, resulting in the large differences you see between the 1991 and 1999 data. The Carya species data is also questionable. In 1991, the hickories were considered all one species and classifed together as Carya spp.(CASP), while in 1999 we attempted to identify the individual hickory species. As a result, we had to consider the hickories (Carya spp) together in both years to make the data consistent. |
|
|
One of the major lessons we take away from this class in Methods for Ecosystem Analysis is the difficulty in quantitative measurement of a dynamic ecosystem. The methods used to gather and analyze the data are subject to a wide array of variables and measurement error. This highlights the need for rigorous quality assurance and control for any method of data collection. Ecosystem analysis is limited by the quality and integrity of the data used. |
|
