Treesearch

To simulate stand-level impacts of climate change, predictors in the widely used Forest Vegetation Simulator (FVS) were adjusted to account for expected climate effects. This was accomplished by: (1) adding functions that link mortality and regeneration of species to climate variables expressing climatic suitability, (2) constructing a function linking site index to climate and using it to modify growth rates, and (3) adding functions accounting for changing growth rates due to climate-induced genetic responses. For three climatically diverse landscapes, simulations were used to explore...

The Interagency Mapping and Assessment Project (IMAP), a partnership between federal and state agencies, is developing mid-scale vegetation data and state and transition models (STM) for comparing the likely outcomes of alternative management policies on forested landscapes across the Pacific Northwest Region. In an STM, acres within a forested ecosystem transition between state classes defined by cover type and seral stage. Transitions resulting from natural and human-induced change can be modeled over long time horizons (centuries). Natural growth and mortality, silvicultural treatments,...

The Forest Vegetation Simulator (FVS) is a prominent growth and yield model used for forecasting stand dynamics. However, users need to be aware of model behavior regarding stocking density, tree senescence, and understory recruitment; otherwise over long projections, FVS tends to concentrate substantial growth on few survivor trees. If the intent is to forecast endemic conditions, model performance can be modified by establishing baseline trends from measured inventory data and configuring FVS to stay within the observed ranges. This paper will present the steps needed to carefully craft...

The “partial” establishment model that is available for most Forest Vegetation Simulator (FVS) geographic variants does not provide an estimate of natural regeneration. Users are responsible for supplying this key aspect of stand development. The process presented for estimating natural regeneration begins by summarizing small tree components based on observations from local Forest Inventory and Analysis (FIA) data sets. Average frequency and height for seedlings and small saplings by tree species are calculated from the data. Seedling recruitment is determined by relationships to the...

Carbon (C) sequestration has become an increasingly important consideration for forest management in North America, and has particular potential in pine-dominated forests of the southern United States. Using existing literature on plantations and long-term studies of naturally regenerated loblolly (Pinus taeda) and shortleaf (Pinus echinata) pine-dominated stands on the Crossett Experimental Forest, allometric biomass equations, and reasonable assumptions about forest product life cycles, we projected the net C pools of the following silvicultural systems over a 100-year period: a short...

Woody biomass utilization presents a tremendous opportunity to address energy independence directly through the use of domestic wood as an energy source that offsets fossil fuel. It also works indirectly through conservation by the substitution of wood for higher embodied energy construction materials such as concrete and steel. Both the direct and indirect measures mitigate climate change by reducing greenhouse gas emissions. By integrating these goals with treatments of forests to make them more resilient to disturbances, longer term C sequestration is accomplished in the live forest on...

Burning wood for energy is a back-to-the-future approach for solving modern problems. The burning of fossil fuels for energy and resultant carbon emissions are global concerns: “The world needs ever increasing energy supplies to sustain economic growth and development. But energy resources are under pressure and carbon dioxide (CO2) emissions from today’s energy use already threaten our climate. What options do we have for switching to a cleaner and more efficient energy future?” (IEA 2008). The basic choice is between action and delay, and forest management is among the set of options...

Silviculturists and ecologists may recommend land management prescriptions that are designed to be resilient to changing climatic conditions. When considering biomass utilization opportunities that may result from climate-change treatments, it really doesn’t matter what species mix or stocking levels are to be retained: if there are trees that need to be harvested, there will usually be opportunities for utilizing woody biomass.

The emissions from delivering and burning forest treatment residue biomass in a boiler for thermal energy were compared with onsite disposal by pile-burning and using fossil fuels for the equivalent energy. Using biomass for thermal energy reduced carbon dioxide emissions on average by 39 percent and particulate matter emissions by 89 percent for boilers with emission control. Over 21 units of bioenergy were produced for each unit of diesel energy used to collect, grind, and haul biomass. At prices in place at the time of the study, utilizing biomass was economically viable on 49 percent...

We describe a portable pyrolysis system for bioenergy production from forest biomass that minimizes long-distance transport costs and provides for nutrient return and long-term soil carbon storage. The cost for transporting biomass to conversion facilities is a major impediment to utilizing forest biomass. If forest biomass could be converted into bio-oil in the field, it may be more profitable to utilize forest biomass for bioenergy. Bio-oil can substitute for fuel oil, or be used as a crude oil and further refined into additional products. Transporting energy-dense bio-oil is more cost...