We observed that non-native forest seemed to have a lack of variety in plants
The native forest had numerous ferns, mosses, and native trees
The non-native forests have a low plant diversity and richness than there would be fewer habitats for native plants and animals
affect water storage
Do the different forest types (native and non-native) hold the same plant diversity and soil characteristics?
If the native (ʻōhiʻa) and non native forest (Eucalyptus, cypress) overstories are equal, then there should be no difference in plant species diversity and soil characteristics.
Kamakou is one of the primary groundwater recharge and surface water source areas feeding the Moloka’i agricultural irrigation system
'ōhi‘a tree is the primary overstory in the preserve
Molokai’s Kamakou Forest, the invasive tree planting began in 1901 by George Munro
Passive and Active Restoration are key in restorational processes
1. We selected four study sites: one near the Wailoku overlook in a stand of E. robusta (elevation around 3,550; Figures 1 and 2), one at the same elevation but with a Monterey cypress overstory, one near the Hanalilolilo Trail with a `ōhi`a lehua overstory (elevation 3,550 feet) outside the Kamakou fence, and one with a `ōhi`a lehua overstory (elevation 4,140 feet) within the fenced area of the Kamakou Preserve.
2. At each site, we randomly selected starting points for our plots. (We closed our eyes, spun, and threw a stick.) Note: Our overall plot locations were not completely random, since they were located within easy access of the Moloka`i Forest Access Road, or the Hanalilolilo Trail, or the Pepeʻopae Bog Trail.
3. We set four100 ft measuring tape at the spot, two from North to South. The other two transect ran from East to West due to safety issues with terrain.
4. At every foot, we measured litter depth and/or moss depth (inches) with a ruler, recorded each plant growth form, and identified plant species
5. Took pictures of unidentified species in all forests
6. Collected approximately one cup of mineral soil from each transect.
7. Recorded bird calls in all plots on the same day
a. Count number of distinct bird calls within a two minute time period.
b. Discuss findings among team members
c. Repeat step 6a and 6b
8. Confirmed all plant species with a specialist
9. Calculated Simpsonʻs Diversity Index for plant species at each location.
10. Used a locally-purchased agricultural soil test kit to test for differences in Phosphorus, Nitrogen, pH, and Potash at each site.
11. Statistically analyze our data to determine if the differences we see are statistically valid given our sample sizes and results.
*Take soil samples about 4” below surface or bellow duff
1. Remove cap from one of the green capped tubes
2. Remove the green capsules
3. Fill the tube will soil until the first line
4. Carefully open the green capsule and pour the powder into the tube with the soil
5. Add water till the fourth line
6. Cap tube and shake thoroughly
7. Allow soil to settle and color to develop for a minute
8. Compare color of solution to the pH color chart
Nitrogen, Phosphorus, and Potash (Potassium) Tests:
1. Fill a clean jar with 1 part soil and 5 parts water
2. Thoroughly shake or stir the soil and water together for a minute
3. Allow the mixture to settle (clearer the better)
4. Remove cap from tube with colored capsules
a. Blue: Phosphorus
b. Purple: Nitrogen
c. Orange: Potash
5. Fill the tube up to the fourth line with the liquid soil mixture
6. Separate a capsule and carefully pour the powder into the tube
7. Cap the tube and shake thoroughly for a minute
8. Allow the color to develop for 10 minutes
9. Compare color of solution to the appropriate portion of the plant food color chart
- Non-native forests have less of a balanced plant growth form community when compared to its native forest counterpart.
- There appears to be an obvious difference in plant species diversity between the native and cypress forests (SDI includes abundance, not just presence)
- Besides the much greater number of species (18-22 vs. 9), there was a striking difference in the ratio of native to non-native species in the different plots (These results differ from Mascaro et al. (2008) on the Big Island)
Based on the data collected, our hypothesis is supported. The native forest plots have higher plant species richness than the non-native plots (Table 1). They also have much higher percentages of native species.
Therefore, the native (ʻōhia overstory) and non-native forest (eucalyptus and cypress overstories) are not equal; there are differences in plant growth form, plant species diversity and soil characteristics.
Through discovering the difference in plant species diversity between native and non-native plots, we hope that we can help make the community of Moloka‘i aware of this issue, and become active in the process of saving our native forests.