Hendricks Park Project

Introduction: The Hendricks Park Service Learning Program team was assigned the task to re-inventory 24 forest monitoring sites originally established in 1999. The team collected data from the main forest monitoring plots and compared the updated forest inventory to the data collected in 1999. The analysis of this information will help aid park staff in determining management strategies to maintain ecological integrity. The data sets below found in tables and graphs are samples of some of data comparisons that are being assessed. See also: Inventory Zone Map

Data Collection ö After visiting the 24 monitoring plots the SLP project team collected data as directed by the established protocols. The graphs and tables below illustrate a few of the many types of data comparisons that will be conducted. These preliminary assessments show some interesting trends, for example overall tree vigor on the monitoring plots has declined slightly. See also: Sample Data Collection Sheet

The table below shows average tree growth for each plot. You may notice some plots seem to have lost growth, which is and indication that some trees were either cut or have fallen.

Average Tree Growth by Plot, Diameter at Breast Height (DBH) measured in centimeters
Plots	1999	2003	Difference	% Change
1-1	22.8	37.4	14.6	63.7
2-1	44.7	47.9	3.2	7.2
2-2	39.7	38.8	-0.9	-2.4
2-3	34.1	38.3	4.2	12.3
3-1	23.6	30.5	6.9	29.1
4-1	73.1	74.1	1.0	1.4
4-2	43.8	45.5	1.7	3.9
5-1	20.3	21.9	1.6	7.9
5-2	27.4	29.6	2.2	8.0
5-3	23.9	26.5	2.6	10.9
6-1	15.5	16.7	1.2	7.7
6-2	29.7	31.0	1.3	4.4
6-3	41.4	42.4	1.0	2.4
6-4	17.7	21.6	3.9	22.0
7-1	46.6	46.5	-0.1	-0.2
7-2	31.8	35.1	3.3	10.4
8-1	21.9	23.6	1.7	7.8
8-2	36.5	37.8	1.3	3.6
8-3	26.3	29.0	2.7	10.3
8-4	38.7	40.0	1.3	3.4
8-5	25.1	27.0	1.9	7.6
9-1	15.7	15.6	-0.1	-0.6
9-2	22.5	25.2	2.7	12.0
9-3	23.2	23.4	0.2	0.9

The following graph illustrates the overall composition of the monitoring plots. Notice the high percentage of Sweet Cherry, an invasive tree species that creates a secondary canopy which can affect the growth of groundcover shrubs and herbaceous plants--creating shade conditions favoring some invasive species.

The table below illustrates the average diameter of major tree species. This information is useful in understanding new growth and which species are reproductively successful in the park's environment.

Major Tree Species in Monitoring Plots 2003 Data ö Diameter at Breast Height (cm)
Species	Avg	Max	Min	Median
Big Leaf Maple	18.6	60.5	5.1	15.6
Douglas-Fir	63.0	131.4	4.5	64.7
Sweet Cherry*	12.6	31.7	4.8	10.7
Oregon White Oak	28.1	63.4	5.7	29.2
Pacific Madrone	15.1	25	7.7	14.9

Forest Inventory Data Analysis