Potential for pH to Limit Oriental Bittersweet Invasion in MN

1. Potential for pH to Limit Oriental Bittersweet Invasion in MN Celastrusorbiculatus Heather Pagelkopf August 14, 2013

2. Botanic Description • Deciduous climbing woody vine • Up to 66’ long • Large root system sends up new shoots • Flowers borne on axillary cymes (clusters along length of vines) • Bright ripe fruit bright red with yellow capsules

3. Botanic Description Celastrus scandens NATIVE Celastrus orbiculatus INVASIVE • Ripe fruit capsules orange with red berries containing <1 seed • Flowers found on terminal panicles • Ripe fruit capsules yellow with red berries containing > 5 seeds • Flowers found on axillary cymes

4. Damage Infests forests, grasslands and urban areas Shades out and smothers low-lying plants

5. Damage Girdles limbs and trunk, eventually causing tree death if phloem is damaged Weighs down limbs and trunk, causing breakage Reduces number of native Celastrusscandens through competition and hybridization

6. Invasive Properties • Extensive root system – regenerates asexually • Hybridization with native C. scandens • Faster growth than native liana • Up to 3 m annually

7. Invasive Properties • Exhibits “sit and wait” growth strategy • Tolerance to wide range of light intensities • Abundant seed production • High rates of germination and establishment

8. Possible Limits to MN Invasion ~ 4.1 to 7.9 ~ 4.6 to 7.1

9. Soil Preferences • Origin data hard to obtain • Literature suggests circumneutral soil preference (6.5 to 7.5) Infestations in MN: • Winona – 6.56 • Red Wing – 6.81 Minneapolis St. Paul Red Wing Winona

10. What Soil pH is Preferred for Growth? Research Questions: Is high pH a limiting factor for C. orbiculatus distribution, or has bittersweet simply not yet spread to regions with high pH? What soil pH values in Minnesota will be suitable for Celastrus orbiculatusseedling vigor?

11. Experimental Procedure • Pre-Germinated Seeds taken from Winona, MN in Nov. 2012 • Transplanted into Ebb and Flow Hydroponic Rockwool System • Three pH Nutrient Solutions: 6.5, 7.2, and 7.9 • Watered and drained every weekday with solutions and flushed with deionized water when EC of drained solution > 3.5 millimhos/cm

12. Preliminary Observations Seedling Deaths: (After 27 Days) pH 6.5 = 8 pH 7.2 = 32 pH 7.9 = 61 Chlorosis: pH 6.5 – very green pH 7.2 – slightly chlorotic pH 7.9 - chlorotic pH 6.5 pH 7.9 pH 7.2

13. Chi-Square Analysis of Seedling Deaths • χ2= 53.947; df = 2 • α < 0.001 • We cannot conclude that seedling death and pH treatment are independent of one another. • Therefore pH is somehow affecting seedling vigor. • Parenthesis indicate expected values.

14. Our study suggests a relationship between soil pH and seedling vigor. Regions of MN with soil pH higher than 7.2 will likely cause some decline in seedling vigor if C. orbiculatusestablishes there. Continued Analysis: • Comparison of leaf chlorophyll levels • Comparison of root and shoot biomass Other Future Study: • Replicated trial using narrow range of pH (e.g 7.5, 7.6, 7.8, and 7.9) • Similar trial using soils obtained from different regions of MN with varying soil pH Implications and Further Analysis

15. Thank You!