Maintaining site quality is critical to sustaining forest productivity and health. Site nutrient supply may be degraded by silvicultural and harvest management operations that extract significant proportions of nutrient stocks. For example, harvest operations that remove whole trees to the landing may have greater impact than bole-only harvests because of significant removal of nutrient-rich tops and limbs to landings.
Impacts of whole-tree harvest nutrient extractions are expected to be lower on sites with high nutrient stocks compared with those of low nutrient stocks. However, there is little information available comparing high and low productivity sites. Forest harvest nutrient removals and site nutrient stocks can be determined, but questions remain over the relative impact of these removals’ site nutrient supply capacity and sustaining site yield into the future.
The Management Effects on Future Forest Productivity project involves a core experiment of long-term plots established on newly harvested sites comparing bole-only versus whole tree final harvesting. Study sites are located on soil/rock types that are considered either poor or high productivity. In conjunction with harvest treatment comparisons, various post-harvest silvicultural treatment options are established within the newly harvested areas. Each of these silvicultural treatments can affect a site’s nutrient status and therefore its productivity.
The long-term study is designed to monitor nutrient pools and seedling growth productivity on a series of permanent plots classified by level of slash retention across the various harvest and silvicultural treatment units and options. The objective is to develop guidelines for various site types that land managers can use to assess probable impact of management operations on future growth.
Conservation and/or enhancement of biophysical site factors through best forest management practices has proven to be one of the most useful methods to maintain or significantly increase forest stand productivity and reduce mortality in many conifer species across a range of geophysical site types in the Inland Northwest.
The IFC has developed balanced management prescriptions based upon current geophysical analysis and mapping and study trials on IFC cooperator’s lands within the Inland Northwest. These prescriptions provide general guidelines based on our understanding of mineral nutrition and forest growth across multitude of soil parent materials geophysical characteristics. These prescriptions can be influenced by the presence of combinations of surficial soil parent material deposits that characteristically differ from the underlying parent material.
Common surficial deposits in the Inland Northwest include glacial, alluvial and lacustrine deposits, volcanic ash and loess. Site type classifications that integrate surficial soil properties, geology and soil moisture regimes can facilitate the development of site-specific guidelines for nutrient capital conservation and thus management prescription.
The goal of the geospatial site type classification project is to integrate various site characteristics to provide best management productivity practices to forest landowners. The objectives are to: (a) integrate existing digital geospatial data layers available through collaborating agencies to develop site type characteristics; (b) define management regimes based on stand productivity and response to amendments from past field research; and (c) prepare management tools based on available data and refine management recommendations as additional data becomes available
The IFC is part of a multi-disciplinary, inter-organizational group of collaborators that include the Rocky Mountain Research Station, Umpqua National Forest, Renewable Oil International® LLC and the University of Montana studying the utilization of forest biomass to produce an energy product.
The biomass to biofuels project is a developing forest management option to help reduce fire hazard forest fuel loads on public lands while producing a sustainable source of bioenergy. Portable pyrolysis units convert biomass into bio-oil in the woods. A byproduct of pyrolysis is bio-char, which is equivalent to the charcoal found in fire ecosystems. Bio-char retains most of the carbon and nutrients contained in biomass and can be used as a soil amendment, which can be left at the field site to maintain soil fertility and sequester carbon in the soil.
Replacing fossil fuel with bio-oil and storing carbon in soil with biochar draws down atmospheric carbon more than other renewable energy schemes. The affects of forest biomass removal and onsite amendment with bio-char are keystone objectives of this collaborative research effort.
Removing forest biomass, such as slash from logging residues, pre-commercial thinnings, or hazard fuel reduction for product utilization has always been impractical, but now is becoming a viable option for land managers with many different benefits.
Innovative technology is emerging that allows conversion of biomass to higher value energy products such as bio-oil. Bio-oil is produced through the process of fast pyrolysis, which is the rapid heating of biomass in the absence of oxygen.
Biochar, typically thought of as a pyrolysis byproduct is receiving attention for its benefits as forest soil amendment. When added back to the soil it returns removed nutrients, acts as a liming agent, improves soil physical properties, and increases water and nutrient retention. Furthermore, biochar is resistant to decay with residence times of thousands of years; therefore, can be used to capture and store atmospheric carbon. Documentation is provided on using forest biomass for producing bio-oil and using biochar as a beneficial soil amendment.
- McElligott, K. 2011. "The Effect of Biochar on Forest Soil Chemical Properties and Tree Growth." IFTNC Annual Meeting. Univ. of Idaho, Moscow.
- McElligott, K. et al. 2011. "Biochar Application Effects On Forest Soil Properties and Woody Biomass Growth." Poster
- Coleman, M. 2011. "Biomass Research Opportunities and Nutrition Management." IFTNC Annual Meeting. University of Idaho, Moscow, Idaho.
- McElligott, K. 2010. "Effects of Biochar on Forest Soil and Plant Growth." IFTNC Annual Meeting. Univ. of Idaho, Moscow.
- McElligott, K. 2009. "Forest Biomass: A Source for Bioenergy, Nutrition, and Carbon Sequestration?" 2009. IFTNC Annual Meeting. Univ. of Idaho, Moscow.
- Shaw, T. M. 2006. "Coram Experimental Forest Logging Study: Nutrient and Biomass Status Related to Utilization Treatment Options." 2006 IFTNC Annual Meeting. Univ. of Idaho, Moscow.
- Johnson, L.R. and T.M. Shaw. 2005. "Impact of Biomass Removals on Forest Nutrient Status and Productivity: UI Experimental Forest Case Study." IFTNC Annual Meeting. Univ. of Idaho, Moscow.
- Coleman, M. "Biochar and Forest Ecology." 2011. Restoring the West Conference 2011. Cooperative Extension, Utah State Univ., Logan (VIDEO).
- McElligot, K.M. 2011. Biochar Amendments to Forest Soils: Effects on Soil Properties and Tree Growth. M.S. Thesis, University of Idaho, Moscow. 103 p.
- Robertson, et al. 2011. Comparing Regional And Site-Specific Biomass and Nutrient Budget Models for Douglas-fir. FRFS, Univ. of Idaho, Moscow. SBS, Wash. State Univ, Pullman.
- Kimsey, M., D. Roche. 2011. Site Preparation Effects on Volcanic Ash Forest Soils and Douglas-fir Regeneration. IFTNC, FRFSci, Univ. of Idaho, Moscow.
- Bioenergy Productions Systems and Biochar Application in Forests: Potential for Renewable Energy, Soil Enhancement, and Carbon Sequestration. UDSA Forest Service Proceedings RMRS-RN-46. 2011
- Can Portable Pyrolysis Units Make Biomass Utilization Affordable While Using Bio-Char to Enhance Soil Productivity and Sequester Carbon? UDSA Forest Service Proceedings RMRS-P-61. 2010
- Portable In-Woods Pyrolysis:
- Main Session Presentation
- Parallel Session Presentation
- Colin Sorenson, A Comparative Financial Analysis of Fast Pyrolysis Plants in Southwest Oregon, 2001
- Washington State Department of Ecology and Washington State University. Methods for Producing Biochar and Advanced Biofuels in Washington State. Part I: Literature Review of Pyrolysis Reactors. Ecology Publication Number 11-07-017. 2001
Links to Portable Pyrolysis Units and Forest Biochar Projects
Much of silviculture involves optimizing growing space of trees in forest stands. Silvicultural treatments or management practices such as planting density and mid-rotation thinnings affect site nutrient availability and therefore forest growth and productivity. IFC site type initiative research is focused on defining nutrient availability of various site types and developing site-type management classifications and prescriptions that integrate soil, geology and forest moisture regimes. Goals for integration of site-type with density management are three fold: 1) develop species-specific density management guidelines for various site types, where site is defined by rock and soil moisture-temperature regimes; 2) target tree nutrient status at various densities on a given site type determined through foliage sampling and estimates of canopy density; and 3) determine which stocking and nutrition combinations maximize young forest stand productivity.
Download the presentation on Site Type Effects on Stocking and Density Management from the Mixed Species Density Management Meeting (June 25, 2014)
Inland Northeast managers treat thousands of acres of forest managed lands annually as a silviculture treatment to reduce competing vegetation and improve seedling growth and survivability in young plantations. The primary objective of IFC is to provide managers with information on operational early stand establishment and seedling growth response across forest site types under various chemical treatment options.
Field trials located on collaborator lands test commonly used herbicide treatments across site-specific soil parent material environments to improve our understanding of soil-species-herbicide interactions and the inferences that can be used to develop an effective and safe chemical site preparation program.