1. Macroinvertebrates of Anza-Borrego by Night and Day
Spencer Breining-Aday, Damin Curtis, Elizabeth Davis, Rachel Liu, Serena Stumpf

2. Why Macroinvertebrates?

3. Desert Environment Extreme temperatures Limited habitat Heat stress
Limited water and desiccation
Environmental stresses affect macroinvertebrates
The composition and distribution may change between night and day
The composition and distribution may change at different locations

4. Do desert macroinvertebrate communities differ between night and day at different locations?

5. Methods 4 Transects, each 45 m long 10 pitfall traps per transect
2 day samples and 2 night sample
one pitfall each 5 meters
Placed in the wash, the north slope, the ridge, and the south slope (not to scale)

6. Methods
Every morning we left at 6am and in the evening we left at 7pm to collect the data
We poured our pitfall trap cups into falcon tubes and labeled them to make it easier to carry it down the ridge

7. Methods Categorized by order and morphotype
Kept one of each morphotype to use as a reference
We figured out which order it belonged to and gave it a morphotype number. For instance coleoptera 1
Poured our samples out onto a plate, moved all of the macroinvertebrates to the side and compared them to our references

8. Quantifying Abundance
Total abundance = sum of individuals from all morphotypes in a sample Day: 13hrs Night: 11hrs Total abundance / # of hours = Hourly abundance Comparable between day and night

9. Refining our Test
Single Factor
Multi-Factor
Night vs. Day F Ratio: 1.2 P: 0.28 Site F Ratio: 4.9 P:
Night vs. Day F Ratio: 1.3 P: 0.25 Site F Ratio: 5.2 P:

10. Results: Abundance
Overall: No significant difference between day and night Between each site: There is a significant difference F Ratio: 3.35 *P < 0.05
Hourly Abundance
Day
Night

11. Morphotype Richness Ordinal Richness Night vs. Day: p-value<0.05

12. Within Order Richness
Day Orders
Night Orders

13. Within Order Abundance
Day Orders
Night Orders

14. What the data means
Overall abundance is not significantly different between day and night
Overall richness is higher at night
There are significant differences between the orders present at day and night.
160 different morphotypes in 2 days

15. Big picture WHY these patterns? Micro environments
Day & Night was pseudo replicated, need to fully replicate

16. Many Thanks Aviva’s ID help & pictures
Blake’s statistics expertise & pitfall help
Jodi & Jack & Maddie for sorting help and emotional support

17. Sources

18. Sampling Design 4 transects: Wash North facing slope Ridge
South facing slope
10 pitfall traps per transect:
45 total

19. Macroinvertebrates in the Desert Environment
Question
Introduction
Results and Discussion
Conclusions
Methods
Macroinvertebrates in the Desert Environment
Nocturnal vs. diurnal