Life Cycle Analysis

Anaerobic digestion is a process where anaerobic bacteria break down organic material to produce biogas. This process occurs naturally in various environments and can be used in anaerobic digesters to treat and dispose of waste, generate biogas, and destroy pathogens. The biogas produced consists mainly of methane and carbon dioxide, with trace levels of other gases. Authors: Gary Felton, Stephanie Lansing, Andrew Moss, and Katherine Klavon; Title: Anaerobic Digestion: Basic Processes for Biogas (FS-994).

A soil quality management issue unique to tree nurseries is the removal of soil off site with sale of the ornamental trees and shrubs, which are harvested with a balled and burlapped (B & B) root ball. The amount of soil removed with B & B harvest and sale has been estimated as much as 5 cm per year. One piece of evidence that has been used to estimate soil loss during B & B tree harvest is the volume of the holes left behind. However, the soil balls wrapped for B & B removal are generally densely permeated with tree roots, leading some to assume that much or most of the ball removed consist of roots rather than soil. There is a dearth of published data on this soil removal or published methods that will allow for reliable calculation of soil being removed from individual enterprises.The main conclusion from this study is that a balled and burlapped (B & B) root ball consists almost entirely (99%) of soil and that the tree roots take up only a negligible portion of the mass and volume. Our results show that in fact the volume of the hole left behind is a reasonable estimate of the volume of soil removed. Authors: Ray Weil, Margaret Guthrie, Chuck Schuster, and Stanton Gill; Title: Assessing the Extent of Soil Loss from Nursery Tree Root Ball Excavation (EB-442)