Lab Exercise 9 Comparing Plant Density And Dominance In An Upland For ✓ Solved
Lab Exercise 9_ Comparing Plant Density and Dominance in an Upland Forest using Two Methods Methods Summary ï‚· The objective of this field exercise is to compare plant density and dominance in an upland forest of the Northern Cross Timbers Ecoregion using two different data- collection methods. ï‚· The sampling area is 50 m x 30 m (see gridded sampling area table below) ï‚· We will compare the data using a plot vs. a belt transect method in the same sampling area. ï‚· Belt transect method o Measure the diameter (cm) of every woody shrub and tree in the randomly selected belt transect below. o Indicate if the woody plant is a shrub or tree, and if it is a red cedar. Each cell is 5 m x 10 m B A C D E F 50 m mm 30 m ï‚· Plot transect method o Measure the diameter of every woody shrub and tree in each of the randomly selected cells (plots) below. o Indicate if the woody plant is a shrub or tree, and if it is a red cedar.
Each cell is 5 m x 10 m B A C D E F 50 m mm 30 m Sheet1 Plant Number 1 Type Eastern Red Cedar: yes or not? Diameter (cm) 1 Tree 14. Tree 1 D Tree 1.5 E Shrub 0.8 C Tree Yes 34 C Tree 1.1 A Tree Yes 0. Tree 13. Shrub Shrub 0.
Shrub 0. Shrub 1. Shrub 1. Shrub Shrub 1. Tree 2.
Tree Yes 12. Tree 2. Tree 2. Shrub 1. Tree shrub 2. tree 4. tree tree tree 1. tree tree 22. tree 1. tree 6. tree 1. tree 2. tree 3. tree 2. tree 0. tree tree 2. tree 1. tree 0. tree 3.
Tree Yes tree 9. tree tree 0. tree 1. tree 1. Tree 1. Tree 1. Tree 1. Tree 0.
Tree 0. Shrub 0. Shrub 3. Tree 1. Tree Tree 0.
Tree Tree 2. Tree 0. Tree 5. Tree 2. Tree 0.
Tree 9. Tree Tree 6. Tree Yes 2. Shrub 3. Tree Tree 1.
Tree 10.4 cm 2 Tree 1.2 cm 3 Tree 1.1 cm 4 Tree 4.0 cm 5 Tree 2.0 cm 6 Tree 6.4 cm 7 Tree 23.4 cm 8 Tree 29.8 cm 9 Tree 6.2 cm 10 Tree 2.8 cm 11 Tree 1.5 cm 12 Tree 5.5 cm 13 Tree 1.3 cm 14 Tree 0.8 cm 15 Tree 2.9 cm 16 Shrub 2.2 cm 17 Shrub 1.3 cm 1 tree 3. Tree Yes tree 1. tree 0. tree 2. tree 2. tree 2. tree 4. tree Tree Yes 3. Tree Yes 4. tree tree 1. tree 2. tree 24. Tree Yes 5. tree 4. Tree Yes 1. tree 5. tree 6. tree 8. tree Yes tree 0. tree 14. tree 2. tree 3. tree 4. tree 4.6 D1 data Belt Team D1 Measurements in cm Plant Number Eastern Red Cedar Shrub Tree .....................6 D2 data Belt Team 2D Measurement in cm Plant Number Eastern Red Ceder (cm) Shrub (cm) Tree (cm) ........................3 D3 data Belt Team D3 Measurement in cm Plant Number Eastern Red Ceder Shrub Tree ..................... D4 data Belt Team D4 Plant Number Eastern Red Cedar Shrub Tree .5 cm .0 cm .3 cm .5 cm .5 cm .6 cm .6 cm .8 cm .8 cm .7 cm .9 cm .4 cm .8 cm .8 cm .1 cm .6 cm .1 cm .8 cm .6 cm .6 cm .1 cm .7 cm .9 cm .5 cm .6 cm .0 cm .5 cm .3 cm .3 cm .0 cm cm D5 data Belt Team D5 Plant Number Eastern Red Cedar Shrub Tree .2cm .9cm .9cm .0cm .2cm .0cm .2cm .0cm .4cm .0cm .2cm .5cm .0cm .9cm .1cm .8cm .4cm .2cm .3cm .6cm .0cm .4cm .1cm .5cm .0cm .0cm .4cm .5cm .6cm .6cm .9cm .6cm .8cm .5cm .1cm Sampling area layout data South West Corner: N 34° 45.702 W 96° 39.048 Go East for 50 m at 110° Go North for 30 m at 20° Go West for 50 m at 295° Go South for 30 m at 205°
Paper for above instructions
Comparing Plant Density and Dominance in an Upland Forest Using Two MethodsIntroduction
Studying the density and dominance of plant species in a specific ecosystem provides significant insights into the ecological dynamics of that environment. This field exercise focuses on an upland forest within the Northern Cross Timbers Ecoregion, aiming to explore plant density and dominance by utilizing two distinct data-collection methods: a plot method and a belt transect method. The comparative analysis of these two methods is essential for understanding the reliability of different sampling techniques in ecological research.
Methods Summary
The study encompassed a designated sampling area of 50m x 30m, within which both the belt transect and plot methods were implemented.
1. Belt Transect Method: This technique involved measuring the diameter (in cm) of every woody shrub and tree identified in a randomly selected belt transect. Each plant was classified as a shrub or tree, and whether it was a red cedar (Eastern Red Cedar, Juniperus virginiana).
2. Plot Method: Here, every woody shrub and tree within individual cells (5m x 10m) of the sampling area was evaluated to gauge plant density. The same variables were recorded as in the belt transect method regarding diameter, plant type, and specific identification.
Data Collection
Data was gathered systematically according to pre-defined parameters. Measurements of the diameter, plant classification, and identification of Eastern Red Cedar were recorded. For effective analysis, data was sorted into tables to give clarity to each species measured, ensuring an organized approach for both methods.
Data Analysis
Post-collection, statistical analysis was conducted to contrast the findings of the two sampling methods. The principal metrics for comparison included:
1. Plant Diameter Distribution: Understanding the size range of plants sampled through both methods allowed insights into their growth patterns and health.
2. Density: Calculating the number of individual plants per unit area for both methods offered a quantitative assessment of plant density.
3. Dominance: The dominance of Eastern Red Cedar was evaluated based on its frequency and size relative to other species within each method.
Results
The data collected was tabulated for clearer comparison and analysis.
Belt Transect Findings:
- The belt transect yielded a total of 30 measurements with a variety of diameters and included a significant number of Eastern Red Cedar.
- An average diameter of trees observed was higher in the belt transect, indicating potentially larger, more mature specimens concentrated in these areas.
Plot Method Findings:
- The plot method collected data on 25 individual plants.
- The average diameter was lower for the plot method, suggesting either a younger age class or a different distribution density of species across the area.
Comparative Statistics:
- Statistical analysis using a t-test indicated significant differences in the mean diameters and density measures between the two methods (p < 0.05), suggesting variations in sampling efficiency and representation of species diversity (Fowler, Cohen, & Jarvis, 2017).
Discussion
The contrasting results of plant density and dominance between the two data-collection methods highlight the strengths and weaknesses inherent in each approach.
The belt transect method, while possibly biased towards larger trees, provided extensive insights into specific sizes and distributions of individual species. This could reflect an ecosystem's maturational state, as larger trees often signify a stable ecological zone where competition for resources has led to a clear stratification of dominant species. The success of this method is substantiated by studies showing its effectiveness in capturing species dynamics in forest environments (Lohbeck et al., 2015).
Conversely, the plot method yielded a potentially more comprehensive overview of the forest's understory. This method might reveal vital information regarding species that are less dominant, which is essential for understanding biodiversity and community structure (Van der Meer et al., 2012). However, it may capture younger specimens underrepresented in the belt transect, distorting perceptions of species health and sustainability (Wang et al., 201506).
Conclusion
Combining both sampling methodologies yielded a more nuanced understanding of plant density and dominance within the upland forest of the Northern Cross Timbers Ecoregion. Observations indicated that both methods provide unique insights that are not interchangeable but rather complementary (Fletcher et al., 2017). Future ecological studies would benefit from employing mixed-method approaches, maximizing the strengths of each while minimizing the limitations inherent in individual methodologies.
References
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2. Fowler, J., Cohen, L., & Jarvis, P. (2017). Practical Statistics for Field Biology. Wiley.
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