Grad Project Slideshare2
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This document outlines a study that aims to quantify plant ground coverage over time using digital photography and image analysis software. The study will compare growth rates of Christmas fern, coral bells, and Allegheny spurge planted alone and together on a shaded, eroding slope. Photographs of test plots will be taken monthly and analyzed using GNU Image Manipulation Program and SamplePoint software to measure plant pixel coverage compared to soil/litter pixels. The results will help select effective native plant combinations for revegetating the slope and reducing erosion.
Grad Project Slideshare2
- 1. Quantifying plant ground coverage using A. Thomas Crawley MALS Graduate Student digital photography and open-source image Virginia Polytechnic Institute and State University editing software ath0mas@vt.edu
- 2. Goal To evaluate and compare growth rates of test groundcover species in various combinations on a shaded, north-facing slope at the Maymont estate. This assessment will be made using a publicly-available, open source graphics editing program.
- 3. Maymont ● Opened to the public 1925 ● 100 acre arboretum. ● Granting institutions include: Institute for Museum Services America the Beautiful Virginia Department of Forestry UTM E: 0280907 UTM N: 4157236 UTM Zone: 18 County: Richmond State: Virginia
- 4. Erosion ● North-facing slope ● Steep grade 30 – 60° ● Exposed tree roots ● Tree stability at risk
- 5. Soil Structure Wateree ● sandy loam ● weak fine granular structure ● very friable ● strongly acid (mg/kg) pH-4.88 P-4 K-92 Ca-371 Mg-60 Zn-2.1 Mn-7.2 Cu-0.5 Fe-16.9 B-0.2 (meq/100g) EST. CEC-6.1 (percentage) Acidity-42.4 Base Sat-42.4 Ca Sat-30.5 Mg Sat-8.1 K Sat-3.9 OM-4.2
- 6. Invasive species English ivy (Hedera helix) & Liriope spicata ● Outcompeting native taxa ● Signs of recovery despite massive removal effort ● Invasives present on the edges of the wooded area have difficulty spreading onto the shaded hillside... ● ...but they stabilize soil.
- 7. Woody Overstory ● Red maple (Acer rubrum) ● Tulip poplar (Liriodendron tulipifera) ● White oak (Quercus alba)
- 8. Woody Understory ● Rhododendron spp ● Dogwood (Cornus florida) ● American Hornbeam (Carpinus caroliniana) ● Eastern Red Cedar (Juniperus virginiana) ● American Holly (Ilex opaca)
- 9. Native Groundcovers ● Christmas Fern (Polystichum acrostichoides) ● Coral Bells (Heuchera villosa) ● Allegheny Spurge (Pachysandra procumbens) The heuchera and ferns will be established as 2” plugs and the pachysandra, bareroot.
- 10. Objectives ● Develop a macro program free to users and capable of using hue selection with digital photographs to measure and compare the areas covered by groundcover plant species. ● Use that macro program to estimate the percentage of ground covered by test plantings at various stages during the first year of growth. ● Use the growth rate information, along with qualitative evaluations of the test plantings, to choose the most effective method to revegetate the shaded, north-facing slope with native plant species.
- 11. Method 1. Establish two sets of six 1m x 1m quadrats within the planting area. 2. Establish the test species and species combinations within each set of quadrats as shown. 3. Using a digital camera and stand constructed for photographing groundcover on a slope, photograph each of the 12 test plots monthly. FERN HEUCHERA PACHYSANDRA
- 12. Method 1. Establish two sets of six 1m x 1m quadrats within the planting area. 2. Establish the test species and species combinations within each set of quadrats as shown. 3. Using a digital camera and stand constructed for photographing groundcover on a slope, photograph each of the 12 test plots monthly. FERN HEUCHERA PACHYSANDRA
- 13. Method 4. Use the GNU Image Manipulation Program to assess the ratio of green (plant) pixels to brown (soil and leaf litter) pixels within the photographed quadrat. 5. Compare the results with those from Samplepoint, a program developed by the USDA which also measures the percentage of ground cover using digital image analysis.
- 14. Method 4. Use the GNU Image Manipulation Program to assess the ratio of green (plant) pixels to brown (soil and leaf litter) pixels within the photographed quadrat. 5. Compare the results with those from Samplepoint, a program developed by the USDA which also measures the percentage of ground cover using digital image analysis.
- 15. Samplepoint ● A manual image-analysis program designed by USDA. ● Facilitates vegetation cover measurements from nadir digital images of any scale. ● Stores classification data to a database as the user classes each point. Originators: Booth D.T., S.E. Cox & R.D. Title: SamplePoint: A manual image-analysis program Release_Date: 2006 Provider: USDA Agricultural Research Service URL: http://www.ars.usda.gov/services/software/download.htm?softwareid=128
- 17. References Booth, D. T.; Cox, S. E.; Fifield, C.; Phillips, P.; Williamson, N. 2004. Image Analysis Compared with Other Methods for Measuring Groundcover. Arid Land Research and Management. 19: 91–100. Booth, D. T.; Cox, S. E.; Berryman, R. D. 2006. Point sampling digital imagery with 'samplepoint'. Monitoring and Assessment. 123: 97–108. Johnson, D. E.; Louhaichi M.; Vulfson, M. 2003. VegMeasure: A C++ Computer Program for Field Measurement of Vegetative Cover, ASPRS 2003 Annual Conference Proceedings. May 2003; Anchorage, Alaska. 8 pp. Richardson, M. D.; Karcher, D. E.; Purcell, L. C. 2001. Quantifying Turfgrass Cover Using Digital Image Analysis. Crop Science 41: 1884–1888 Rotz, J. D.; Abaye, A. O.; Wynne, R. H.; Rayburn, E. B.; Scaglia, G.; Phillips, R. D. 2008. Classification of digital photography for measuring productive groundcover. Rangeland Ecology & Management. 61: 245–248. Wells, K.F. 1971. Measuring Vegetation Changes on Fixed Quadrats by Vertical Ground Stereophotography. Journal of Range Management, 24: 233–236.