Effects of Biomass Production and Harvesting on Environmental Quality

1. Effects of Biomass Production and Harvesting on Environmental Quality Erik B. Schilling National Council for Air & Stream Improvement Southern Regional Center Newberry, FL

2. General Facts • Currently 32M acres of plantation forests in SE US • Predominately Loblolly Pine, lesser extent Slash Pine • SE US average growth rate of 5 tons ac-1 yr-1 • This is much less than many forest plantations throughout the world • Models, field trials, etc. indicate that growth rates exceeding 10 tons ac-1 yr-1 are biologically feasible.

3. Increasing Growth Rates • Genetics • Improve desired ecophysiological traits • Leaf area, water and nutrient use efficiency, etc. • Fertilize • Reduce competition • Traditionally, mechanical site preparation • Costs can be high, potential for environmental impacts • Today, industry relying heavily on chemical site preparation – herbicides

4. Soils and Sediment

5. Sediment and Intensive Forestry Temple Inland Alto Watersheds McBroom 2005 Blackburn et al. 1986

6. Fertilization, Herbicides and Water Quality

7. Forest Fertilization • Over 1.5M acres fertilized with P or N+P in 2002 • Mid-rotation fertilization (stand age 8-15 yrs) • 85% of FNC stands respond to fertilization • 150-200 lbs N + 25 lbs P acre most common • Costs - $100 per acre Fox et al. 2006

8. Forest Fertilization and Water Quality • NCASI Technical Bulletin #782 • National review of forest fertilization studies • Forest fertilization commonly leads to moderate increases in streamwater nutrient concentrations • Greatest nutrient increases come from: • Direct application to streams • Ammonium nitrate forms of fertilizer • Excessive application rates • Repeated applications • Even in these situations, impacts are too small to degrade water quality

9. Carteret 7 Study • Loblolly pine (15-yr-old stand) • 170 kg N + 28 kg P ha-1, as urea and DAP • Ground application • Nutrient concentrations • NO3 increased from 0.6 mg/L to 1.2 mg/L • NH4 increased from 0.06 mg/L to 3.8 mg/L • P increased from 0.04 mg/L to 0.18 mg/L • Returned to baseline levels ~ 3wks • Important to note that streams were avoided Campbell 1989

10. Why Interest in Herbicides? • Herbicide applications reduce competition for: • Light • Water • Nutrients • Increased productivity • Reduce site preparation costs • Questions on the fate of herbicides: • Water quality • Aquatics • Wildlife Haywood et al. 2003

11. Herbicide ResponseTemple Inland Alto Watersheds NCASI 2006

12. Herbicide Toxicity • Maximum measured concentrations • Hexazinone - 30 ppb • Imazapyr - 40 ppb • Detection levels below 1 ppb generally less than 150 days after application • Imazapyr and Hexazinone • Published LC50 values = 106 ppb NCASI 2006a, NCASI 2006b

13. Watershed Studies in the South • Consistent trends observed • Small, temporary changes in stream hydrology • Small, temporary changes in stream water chemistry following fertilization • Extremely low levels of herbicide residues • Disturbance events can be more significant than ‘intensive’ management prescriptions using fertilization and herbicides • Tropical and summer storm events significant

14. Harvesting

15. Forestry BMP Efficacy in the SE Figure from M. Miwa, International Paper

16. BMPs Simplified to Five Principles • Minimize bare ground and soil compaction • Separate bare ground from surface waters • Separate fertilizer and pesticide application from surface waters • Provide a forested buffer around streams • Engineer stable road surfaces and stream crossings Jackson and Olzewski 2005

17. Roads and Stream Crossings • Harvesting does not result in declines in environmental quality • Soils and Water • Roads & Stream Crossings are the greatest threats to water quality when… • BMPs not utilized • BMPs installed improperly • State BMP compliance reports point this out

18. Thank You…