Understanding the role of biochar in site restoration and carbon sequestration Deborah S. Page-Dumroese USDA Forest Service-Rocky Mountain Research Station ddumroese@fs.fed.us
Overview Dead trees and slash piles Why biochar? Why not Wood chips? Masticated wood? Opportunities Carbon sequestration
What is happening? Millions of acres of overstocked forests in the western US Millions of acres of beetle-killed forests in Canada and western USA Longer fire season and increasing fire severity Smaller burn windows Insect and disease risk map
What to do with the waste (non-merchantable) wood?
Current land management Forest restoration: thinning and salvage logging Pile and burn excess woody biomass Cheap, easy, reduces fire risk Pile burning can alter soil properties Long-term impacts
Slash pile burning Significant waste of energy Releases CO 2 and other GHG into the atmosphere Concentrates site nutrients at burn pile Volatilization loss of N, OM, etc. Kills bacteria and fungi No trees can grow!
Other concerns Bioenergy harvesting could degrade long-term productivity Sustainable harvesting and site impacts Air pollution
Chipping Chip on site Relatively uniform pieces Soil cover Can be applied too thick May block air and water into the soil Not a recalcitrant form of C Few long-term benefits
Mastication Make on-site Large and small pieces of wood Surface application Soil cover Not a recalcitrant form of carbon Few long-term benefits
Biochar Can be made on-site Converts waste wood into a recalcitrant form of carbon Alters soil physical and chemical properties Surface application that moves into the mineral soil Many long-term benefits
Making biochar Slash Kilns of piles various designed sizes to make more char. Plan to quench. Fast Pyrolysis
Some opportunities Forest Range Mine
Forest opportunities Use slash from thinning projects Restoration treatments Applied on top of forest floor
Key findings forest sites Slight increase in tree growth Increased available water Carbon sequestration Coarse-textured soil responds more robustly than fine-textured soil!
Mine land restoration opportunities Approximately 38,000 abandoned mine sites on Forest Service lands in the western US Used biochar, wood chips, and biosolids Biochar made from mixed conifer feedstock and fast pyrolysis
Key findings mine land restoration Combination treatments provided: Ground cover Better seed germination Better seedling survival Sequester C and improve soil moisture Increased water availability under biochar treatments
Rangeland opportunities Restoration of rangelands for increased forage Used piñon-juniper feedstock and fast pyrolysis Seeded with a local mix
Range restoration key findings No change in greenhouse gas emissions in treated plots Increased soil moisture PJ biochar sequesters 6-7 tons/acre C
Forest-to-farm opportunities Dead wood Slash/Residues Pyrolysis Manure filtering Increase crop yields Reduce methane Food supplement Animal bedding
Biochar Opportunities Using waste wood to create biochar reduces the need for slash piles Reduces GHG and particulate emissions Avoids long-term soil impacts Fast pyrolysis biochar is ~80+% C Forest floor applications of biochar impact the mineral soil within 2-5 years
Reducing Risk/Increasing Benefits Increase soil water Decreased wildfire Decrease insect risk Decrease disease risk Increase soil carbon Climate change Carbon credits Decrease GHG emissions
Biochar Opportunities Soil moisture in a changing environment With a 1% increase in soil OM, water holding increases from 2-4% Texture dependent 10,000-25,000 gallons of additional water Significant ways to increase: Agricultural yields Forest health Range forage Ecosystem services
What is the role of biochar? Waste woody biomass converted to biochar can: Increase food yields 10 tons/acre biochar increased wheat yield up to 35% Increase tree resistance to insects and disease Restore skid trails, log landings, road beds water relations carbon sequestration Improve soil resiliency less erosion and leaching; improved infiltration; more resilient to floods and droughts
This research is supported by: USDA National Institute of Food and Agriculture and Department of Energy, Biomass and Research Development Initiative, Competitive Grant DE- EE0006297
Thank you! Deb Page-Dumroese ddumroese@fs.fed.us