Normalized Difference Vegetation Index (NDVI)
The three treatments followed similar patterns of increased productivity (as measured by the “greenness” derived from reflected light from the plot) through the growing season. Both the drought and heat treatments maintained consistently higher levels of greenness than the control treatment. Heated plots yielded a higher level of primary productivity than either the drought or control treatments. Based on our observations from the field, we believe that the higher primary productivity in the heated plots could be due to invasive grasses rather than greater productivity of the focal species. However, one way ANOVA for each day data was collected revealed no significant differences (p<0.05) between any of the three treatments.
Figure 1: Average NDVI value by treatment
Figure 2: The average NDVI readings for each of the three treatments on Julian day 110 (April 19), the day on which the average NDVI measurements showed the highest deviation between treatment averages. One way ANOVA analysis shows that the difference between these measurements were not significant (p=0.2353, F-statistic =1.5775).
Phenology
Figure 3: Timing of flowering, senescence, and seed set on Julian day for 15 native plant species based on different treatment groups over an eight week observational period.
Only 9 out of the 15 focal species produced flowers during our eight-week observational period. Out of the nine species that flowered, seven flowered first in the heated plots, where Plectritis congesta and Thysanocarpus radians flowered first in the other treatment groups (Figure 3). There was no specific pattern evident for the timing of first flowering for each of the flowering species. Senescence and seed set occurred first within the heated plots for six of the nine species that flowered during our observation period (Figure 3).
Figure 4: Graph of which treatment group contained the most flowers within a single plot per flowering species, with two species (Sidalcea Malviflora and Thysanocarpus radians) counting in two groups since they had similar max values.
All but two of the species produced maximum flowers in a single plot solely within either the heated or drought treatment (Figure 4), with only two species (Plectritis congesta and Sidalcea malviflora) having maximum flowers in the control plots. However, even for these two species, we observed a similar number of maximum flowers in the drought treatment for Plectritis congesta and the heat treatment for Sidalcea malviflora. (Appendix A). The patterns in maximum flowering vary between species, where some species showed larger differences in maximum flowers produced within treatment groups, such as Eriophyllum lanatum (Appendix A). On the other hand, some species produced nearly equal maximum flowers between multiple treatment groups, such as Sidalcea malviflora (Appendix A).
Sidalcea malviflora (rosy checkermallow)
Figure 5: Total reproduction of all Sidalcea malviflora plants at the Willow Creek site by treatment. Total reproduction includes flowers, buds, and fruits.
Figure 6: The total number of flowering plants. Nine plants flowered in total, one in the drought treatment, three in the control treatment, and five in the heat treatment.
Figure 7: Total reproduction of Sidalcea malviflora (rosy checkermallow) by treatment.
Figure 8: Basal area of individual plants by treatment. Note that not all outliers are shown; both the heated and control plots had a single outlier with a basal area over 5000cm2.
Figure 9: The histogram illustrates the right skewness between the number of plants and the basal area.
Figure 10: Number of leaves by treatment. Outliers greater than 25 are not shown.
Analysis of the Sidalcea malviflora data was conducted by treatment on three measures of plant size and fitness: the total number of leaves per plant, total reproduction per plant (defined as the number of flowers and fruits), and basal area of each individual plant. The basal area data indicated a mean for the entire data set of 70.6cm2 and a median of 4.4cm2. Of the 366 plants measured, the largest measured basal area was 5586cm2 and the largest calculated total reproduction for an individual plant was 792, which is represented as the only outlier in the heated treatment (Figure 5). The mean number of leaves for the entire dataset was 4.7 leaves per plant. The mean total reproduction for the entire dataset was 169.3 and the max total reproduction was 792. Of 366 plants measured, a total of 9 plants flowered; one plant in the drought treatment, three plants in the control treatment, and five plants in the heat treatment (Figure 5). The relative pattern of total reproduction by treatment is the same pattern as the number of plants that flowered by treatment (Figure 5 & 6). The total number of leaves, total reproduction, and basal area for each individual plant were each greatest in the heat treated plots.
The total number of leaves (F=1.801, p=0.167) and the basal area of individual plants (F=2.126, p=0.121) varied more among treatments than within treatments. In contrast, the total reproduction data (F= 0.102, p=0.905) illustrates that there is more variability within treatments than among treatments. However, there were no statistically significant differences between treatments. ANOVA statistics were analyzed with two degrees of freedom.
The data concerning basal area is extremely right skewed (Figure 9). Due to this the mean is greatly affected, thus the median is a more accurate representation of basal area. The inner quartile range consists of values ranging from 2.00cm2 to 4.00cm2, which indicates that the middle 50% of the distribution lies between these two points (Figure 10).
Appendix A: Maximum Flowering Graphs for Each Flowering Species
Figure 1: Max flowering for Clarkia purpurea focal species based on the highest total number of flowers recorded in a single plot for each type of treatment group.
Figure 2: Max flowering for Collinsia grandiflora focal species based on the highest total number of flowers recorded in a single plot for each type of treatment group.
Figure 3: Max flowering for Danthonia californica focal species based on the highest total number of flowers recorded in a single plot for each type of treatment group.
Figure 4: Max flowering for Eriophyllum Lanatum focal species based on the highest total number of flowers recorded in a single plot for each type of treatment group.
Figure 5: Max flowering for Festuca roemeri focal species based on the highest total number of flowers recorded in a single plot for each type of treatment group. 
Figure 6: Max flowering for Navarretia pubescens focal species based on the highest total number of flowers recorded in a single plot for each type of treatment group.
Figure 7: Max flowering for Plectritis congesta focal species based on the highest total number of flowers recorded in a single plot for each type of treatment group.
Figure 8: Max flowering for Sidalcea malviflora focal species based on the highest total number of flowers recorded in a single plot for each type of treatment group.
Figure 9: Max flowering for Thysanocarpus Radians focal species based on the highest total number of flowers recorded in a single plot for each type of treatment group.