Wednesday, January 13, 2016

Forest succession lab

We recently used data provided to us that took a census of tree species regarding size and number in given plots of land.  We graphed all of this data, and then the data of specific trees in order to observe the trends in the growth of the forests in these plots of land.
Full Group Data
Total Area=
3,000 sqft






Species
Saplings
Young
Adult
Mature
Old
Over-Mature

Species Density
Black Birch
23
17
0
1
0
0

#VALUE!
Dogwood
10
11
4
0
0
0

#VALUE!
Tulip Tree
5
0
0
0
5
21

#VALUE!
American Beech
8
17
5
7
16
3

#VALUE!
Sugar Maple
578
58
3
0
0
0

#VALUE!
Black Cherry
2
3
5
4
0
0

#VALUE!
Black Oak
0
0
0
0
5
4

#VALUE!
White Ash
0
3
0
0
3
5

#VALUE!
Chestnut Oak
1
0
0
3
15
8

#VALUE!
Red Maple
22
21
4
9
3
0

#VALUE!
Sweet Gum
0
0
0
6
16
27

#VALUE!















Total Tree Density

#VALUE!









Species
% Saplings
% Young
% Adult
% Mature
% Old
% over mature
Black Birch
56.09756098
41.46341463
0
2.43902439
0
0
Dog Wood
40
44
16
0
0
0
Tulip Tree
16.12903226
0
0
0
16.12903226
67.74193548
American Beech
14.28571429
30.35714286
8.928571429
12.5
28.57142857
5.357142857
Sugar Maple
90.45383412
9.076682316
0.4694835681
0
0
0
Black Cherry
14.28571429
21.42857143
35.71428571
28.57142857
0
0
Black Oak
0
0
0
0
55.55555556
44.44444444
White Ash
0
27.27272727
0
0
27.27272727
45.45454545
Chestnut Oak
3.703703704
0
0
11.11111111
55.55555556
29.62962963
Red Maple
37.28813559
35.59322034
6.779661017
15.25423729
5.084745763
0
Sweet Gum
0
0
0
12.24489796
32.65306122
55.10204082









 

We picked 5 different trees to show their spread across the sapling, young, adult, mature, old, and over mature size differences, in order to show when trees first show up in the forest.  the more old trees that there are, the longer that those trees have been present, making them pioneer species.  we picked Dogwood, Red Maple, Tulip Tree, Black Birch, and American Beech because they all have similar numbers of total specimens, but they vary in terms of size distribution.  We can see that tulip and beech trees are among the first present, while red maple, black birch, then dogwoods followed.  

In 50 years, this forest will have likely changed its dominant species.  The ash, oak, tulip, and sweet gum all had mostly old and over-matured individuals in this plot, so they will likely be less present in the future.  The two maple species both have many young individuals which will likely dominate the forest in the future, while the other species like beech, dogwood, and black birch will also be present, but not in the same numbers as the sugar maple.  Contrast this to 50 years ago, when the beech, tulip, chestnut oak, and sweet gum were the only trees that were present in any sort of size, and we can see the changes that occur in a forest as it grows and develops.  These changes happen because certain trees are better at growing in certain environments.  We can assume from this data that the sugar maple needs a semi-established forest before it is able to thrive, while species like the tulip and sweet gum do better before other trees have come into an ecosystem and crowded them out.  I’m completely confident with the data that we used in the lab because it was provided for us.  There isn’t any source of error in identifying the trees, because this isn’t necessarily a real plot of land, just a set of data.

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