19 Oct 2008, 11:17am
Ecology Management
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Intense forest wildfire sharply reduces mineral soil C and N: the first direct evidence

Bernard T. Bormann, Peter S. Homann, Robyn L. Darbyshire, and Brett A. Morrissette. 2008. Intense forest wildfire sharply reduces mineral soil C and N: the first direct evidence. Can. J. For. Res. 38: 2771–2783 (2008).

Full text [here]

Selected excerpts:

Abstract:

Direct evidence of the effects of intense wildfire on forest soil is rare because reliable prefire data are lacking. By chance, an established large-scale experiment was partially burned in the 2002 Biscuit fire in southwestern Oregon. About 200 grid points were sampled across seven burned and seven unburned stands before and after the fire. Fire-related soil changes — including losses of soil organic and inorganic matter — were so large that they became complicated to measure. The 51 Mg ha–1 of loose rocks on the soil surface after fire suggests erosion of 127 Mg ha–1 of fine mineral soil, some of which likely left in the fire plume. After accounting for structural changes and erosion with a comparable-layers approach, combined losses from the O horizon and mineral soil totaled 23 Mg C ha–1 and 690 kg N ha–1, of which 60% (C) and 57% (N) were lost from mineral horizons. Applying a fixed-depth calculation — commonly used in previous fire studies — that disregards structural changes and erosion led to underestimates of loss of nearly 50% for C and 25% for N. Although recent debate has centered on the effects of postwildfire forest management on wood, wildlife habitat, and fuels, this study indicates that more consideration should be given to the possible release of greenhouse gases and reduction of future forest productivity and CO2 uptake.

Introduction

Forest ecologists think of wildfire as an important natural process that regulates fuel accumulation and successional patterns across most western US forests (DeBano et al. 1998). Forest wildfires also have great societal consequences. Rural communities and firefighters are well aware of the dangers of high-intensity (high-temperature) large-scale fires. Given dry conditions and sufficient fuels, these fires can make their own weather, spread at alarming rates, and often become nearly unstoppable. The monetary and human costs of fighting such fires — loss of property, timber, wildlife habitat, water quality, C stocks, and other resource values, and remediation expenses — can be substantial (Neuenschwander et al. 2000; Dombeck 2001). The direct cost of fighting wildfires nationally in 2002 was $1.6 billion, with nearly a tenth of this budget spent on a single fire, reported on here, called the Biscuit complex fire, in southwestern Oregon, USA (Government Accounting Office 2004). …

Current understanding of the ecological effects of intense wildfire is severely limited by the lack of detailed knowledge of soils before wildfire. To date, only one study has reported effects of wildfire based on before and after soil sampling, but fire intensity was unknown (Murphy et al. 2006; Johnson et al. 2007). …

When the 2002 Biscuit fire serendipitously burned through part of a 150 ha Long-Term Ecosystem Productivity (LTEP) experiment (Bormann et al. 1994; Homann et al. 2008), we were given an opportunity to examine soil changes in paired pre- and post-wildfire samples. Because we had clear evidence that these plots had burned at high intensity, our objective was to determine the effects of high-intensity fire on the loss of soil C and N mass. Volumetric soil sampling, which has not been conducted in previous wildfire studies, allowed us to rigorously evaluate changes on a per-area basis. The parallel data from unburned stands provided important evidence on soil development that was not attributable to the fire. Having archived prefire samples also allowed us to reduce analytical biases. By combining these data, we provide an assessment of the potential effects of wildfire that is the most rigorous to date. Our assessment of soil physical and chemical changes provides unique information about the effects of high-intensity forest wildfire on soils and greenhouse-gas emissions, along with important implications for long-term productivity and future C sequestration. …

Results

The clearest effect of intense wildfire on our plots, which has also been widely noted across the Biscuit fire,2 was a substantial increase in the amount of near-surface rocks on the burned plots — there was 51 ± 8 M ha–1 (mean ± 95% CI) of loose rocks on the soil surface after the fire. (Fig. 5). …

The second notable effect of high-intensity fire was the major loss of soil organic matter at the soil surface that extended into the mineral soil, and corresponding losses of soil C and N. In the uppermost comparable layer 1 (the O horizon and mineral soil to 3.7 cm), soil C decreased by 19 ± 2 Mg ha–1 from the prefire sampling value in 1992 (Fig. 7 left side, Table 4 method 1). A small but significant (p <0.05) amount of C (2.5 Mg ha–1) was lost from the two deepest layers combined (4 and 5). If all C in the prefire O horizon (9 ± 1 Mg ha–1) was combusted, then 60% of the soil C loss came from mineral soil layers.

Soil N losses were also large, 547 ± 79 kg ha–1. No significant subsurface soil N losses were seen, but an increase of 40 ± 32 kg ha–1 was observed in layer 3. If all N in the prefire O horizon (226 ± 21 kg ha–1) was volatilized, then 57% of the soil N loss came from mineral soil layers. …

Discussion

Comparison to other studies

Our estimated loss of 23 Mg C ha–1 from organic and minerals soil layers is higher than most previous estimates. Our losses of 500 to 700 kg N ha–1 fell in the upper range of reported values. Comparing our results with others is challenging, however, given the variety of assumptions, sampling methods and depths, and analyses used. Uncertainties with these studies come from multiple sources and cloud our knowledge of the effects of intense fire on soils. Because of the lack of opportunities to directly measure soil changes before and after intense wildfire, researchers have had to rely on estimates obtained in retrospective studies or extrapolated from laboratory and lower-intensity prescribed fire studies. …

We cannot rule out a bias in retrospective studies because they assume that unburned areas can be used to represent the preburn conditions (Baird et al. 1999). Inherent differences between burned and unburned areas with respect to moisture, site conditions, and burn history can influence soil properties, as has been demonstrated for part of the Biscuit fire (Thompson et al. 2007). Different site histories confound interpretations and may lead to incorrect conclusions about soil dynamics (Yanai et al. 2003). …

Several mechanisms may explain the loose surface rocks after fire (Fig. 3): postfire erosion of fines, small-scale resorting of soil constituents, and atmospheric losses during the fire. Most of the soil organic matter in the O horizon was burned, and the products of combustion, including CO2 and volatilized nutrients, were exported as gas or smoke particles, leaving behind over seven times more rocks above the mineral soil surface. Losses of fine mineral soil from upper mineral soil layers are usually attributed to postfire waterdriven erosion, and our erosion-box estimates support this explanation to a point. Water-driven erosion for the 2003–2004 water year on burned soils in erosion boxes, placed across a range of slopes, averaged 57 m3 ha–1 compared with 0 m3 ha–1 on unburned soils. Below a 15 ha catchment with two burned LTEP stands, only a tiny fraction of the estimated 850 m3 of moving sediment (extrapolated from the erosion-box data) appeared in the ditches along logging roads. The export of the 127 Mg ha–1 of missing soil, estimated by the difference between pre- and post-fire soil sampling (Fig. 6) and extrapolated to this catchment, would be about 1900 m3 (assuming a sediment bulk density of 1 Mg m–3). The complex microtopography — partly created by windthrows, downed logs, tree trunks, and needles cast off after the fire — appeared to capture much of the moving soil. The fire also created soil voids — where decayed stumps and roots burned deeply into the soil — that filled over time. This vertical sorting mechanism does not appear to be responsible for the increase in the amount of surface rocks because we observed no corresponding drop in the
rock concentration at deeper soil layers (Fig. 5).

An intriguing alternative explanation for most of the missing fine soil is transport via the massive smoke plume. The elevation of the smoke column and the spread of the plume provide a plausible convective erosion process for off-site transport of substantial material. Large plumes of smoke, some more than 1500 km long, were visible most days during the months of the fire from the NASA MODIS satellite (Fig. 9). Fine soil particles have been detected in smoke (Palmer 1981; Samsonov et al. 2005), and wind speeds near the soil surface — driven by extremely strong vortices resulting from fire-driven atmospheric convection (Palmer 1981; Banta et al. 1992) — can carry smoke to the lower stratosphere (Trentmann et al. 2006). The possibility that a substantial mass of fine particles, including mineral soil, was transported high into the atmosphere raises questions about the effects of intense fire on radiation interception, water-droplet nuclei, and off-site terrestrial and ocean fertilization.

Implications of intense-fire-induced soil changes on climate, forest productivity, and management decisions

Many previous estimates of fire contributions to greenhouse gasses (e.g., Crutzen and Andreae 1990) are based on biomass combustion alone and fail to consider mineral soil losses. Although Campbell et al. (2007) considered soil C losses from the entire Biscuit fire, a concern about the lack of prefire soils data in their estimates is expressed in the range of their C-emission estimates, 0.7 to 1.2 Tg C for the portion of the fire with vegetation damage classes similar to those of our plots. If we extrapolate our results to this area of the Biscuit fire, the resulting soil C loss would be about 1.6 Tg and N loss about 45 Gg. Mineral soil (<4 mm) particulate losses (Fig. 6), extrapolated to the same area, sum to nearly 9 Tg.

Our soil C loss is greater than the high end of the estimates of Campbell et al. (2007); this discrepancy may be related to bias from their unburned controls or to our small sample of the Biscuit fire area. To the extent that our estimates might apply more broadly to other intense fires, climate models may need to be recalibrated to account for effects of intense fire, including fire-induced greenhouse gases and emissions of particulates.

The intensity of wildfires and magnitude of losses of fine soils and soil C and N have additional implications for soil fertility and subsequent rates of plant production and C sequestration. Soil C losses lead to increased bulk density and reduced soil water-holding capacity, cation-exchange capacity, and sources of energy for microbial communities. To the extent that soil N, soil C, and soil structure control productivity, these changes should result in major declines that will last as long as it takes to return to prefire conditions. …

Any potential loss in productivity is relevant to the US National Forest Management Act of 1976, where the Secretary of Agriculture is required, “through research and continuous monitoring, to ensure that management systems will not produce substantial and permanent impairment of the productivity of the land”. The US Endangered Species Act of 1973 is also relevant to the management of high-intensity fires, for example, in the case of the northern spotted owl that nests primarily in stands of large trees averaging only 32 large trees ha–1 (Hershey et al. 1998). When soils can no longer produce such trees, the area of suitable habitat that could redevelop after fire is also lessened.

Much of the recent debate has centered on the effects of postwildfire management on tree regeneration, wildlife habitat, and future fire risk (Donato et al. 2006; Newton et al. 2006; Shatford et al. 2007; Thompson et al. 2007). In light of the first direct evidence of major effects of intense wildfire on soils — based on extensive and detailed pre- and post-fire soil sampling — we think that soil changes, especially the potential loss of soil productivity and greenhousegas additions resulting from intense wildfire, deserve more consideration in this debate. In forests likely to be affected by future intense fire, preemptive reduction of intense-fire risks can be seen as a way to reduce losses of long-term productivity and lower additions of greenhouse gases. Preemptive strategies may include reducing fuels within stands but also improving fire-attack planning and preparation and changing the distribution of fuels across the landscape to reduce the size of future fires. Practices can include thinning and removing or redistributing residues and underburning.

In forests already affected by intense fire, amelioration to increase C sequestration, tree growth, and eventually late successional habitat should be strongly considered. Amelioration practices might include seeding or planting N2-fixing and other plants, fertilizing, and managing vegetation and fuels through time. To the extent that receipts from pre- and post-wildfire logging are the only means of paying for these practices, such logging should be balanced against other management objectives and concerns. Harvesting before and after fire to generate revenue, if done improperly, has the potential to harm soils, but this outcome needs to be weighed against the outcomes resulting from increased high-intensity fire and from not ameliorating after soils have been burned intensely.

1 Sep 2008, 5:00pm
Ecology
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Interactions Among Livestock Grazing, Vegetation Type, and Fire Behavior in the Murphy Wildland Fire Complex in Idaho and Nevada, July 2007

Karen Launchbaugh, Bob Brammer, Matthew L. Brooks, Stephen Bunting, Patrick Clark, Jay Davison, Mark Fleming, Ron Kay, Mike Pellant, David A. Pyke,and Bruce Wylie. 2008. Interactions Among Livestock Grazing, Vegetation Type, and Fire Behavior in the Murphy Wildland Fire Complex in Idaho and Nevada, July 2007. Open-File Report 2008–1214, U.S. Department of the Interior U.S. Geological Survey.

Prepared in cooperation with the Murphy Wildland Fire Grazing and Fuel Assessment Team

Full text [here]

Selected excerpts:

Abstract

A series of wildland fires were ignited by lightning in sagebrush and grassland communities near the Idaho-Nevada border southwest of Twin Falls, Idaho in July 2007. The fires burned for over two weeks and encompassed more than 650,000 acres. A team of scientists, habitat specialists, and land managers was called together by Tom Dyer, Idaho BLM State Director, to examine initial information from the Murphy Wildland Fire Complex in relation to plant communities and patterns of livestock grazing. Three approaches were used to examine this topic: (1) identify potential for livestock grazing to modify fuel loads and affect fire behavior using fire models applied to various vegetation types, fuel loads, and fire conditions; (2) compare levels of fuel consumed within and among major vegetation types; and (3) examine several observed lines of difference and discontinuity in fuel consumed to determine what factors created these contrasts.

The team found that much of the Murphy Wildland Fire Complex burned under extreme fuel and weather conditions that likely overshadowed livestock grazing as a factor influencing fire extent and fuel consumption in many areas where these fires burned. Differences and abrupt contrast lines in the level of fuels consumed were affected mostly by the plant communities that existed on a site before fire. A few abrupt contrasts in burn severity coincided with apparent differences in grazing patterns of livestock, observed as fence-line contrasts. Fire modeling revealed that grazing in grassland vegetation can reduce surface rate of spread and fire-line intensity to a greater extent than in shrubland types. Under extreme fire conditions (low fuel moisture, high temperatures, and gusty winds), grazing applied at moderate utilization levels has limited or negligible effects on fire behavior. However, when weather and fuel-moisture conditions are less extreme, grazing may reduce the rate of spread and intensity of fires allowing for patchy burns with low levels of fuel consumption.

Introduction and Background

The sagebrush steppe ecosystem dominates about 73 million acres of western North America, but this amount is only about 55 percent of its historical potential (Connelly and others, 2004). Fire has been a major factor contributing to this change. More frequent and larger fires are a growing reality in the management of western rangelands. In Idaho and Nevada, the last decade (1997 to 2007) has yielded 18 fires greater than 100,000 acres. However, the size of these very large fires appears to be increasing given that 6 of the 10 largest fires of the decade occurred in 2006 and 2007 (National Interagency Fire Center [NIFC] records; http://www.nifc.gov). Impacts on natural and fiscal resources are high during those years when large acreages burn. Annual weather conditions undoubtedly contribute to the acreage burned in any given year, but other factors also may contribute to the risk of wildfire in the sagebrush steppe ecosystems. These factors include (1) changes in livestock management, such as reductions in stocking rates and changes in grazing seasons; (2) increased abundance of invasive species, such as cheatgrass; and (3) increased wildland-urban interfaces where human-derived ignitions can occur (Miller and Narayanan, 2008).

Heavy livestock grazing is thought to have affected fire regimes by severely reducing fuel loads and thereby reducing the potential for fires to sustain ignition and spread. The introduction of cattle, sheep, and horses to the Great Basin in the 1860s quickly created large ranching operations and excessive grazing pressure. The severe overgrazing removed fine fuels and resulted in a substantial reduction in the number of fires and the acres burned. Only 44 fires, burning a total of 11,000 acres, were reported from 1880 to 1912 in Great Basin rangelands (Miller and Narayanan, 2008). Evidence for reduced numbers of fires during this period is also deduced from the near elimination of fire scars on trees adjacent to sagebrush ecosystems during the late 1800s and continuing through most of the 1900s (Miller and Rose, 1999; Miller and Tausch, 2001).

The number of livestock in Great Basin and sagebrush ecosystems has dropped rapidly since the passage of the Taylor Grazing Act of 1934 (43 USC 315; http://www.blm.gov/wy/st/en/field_offices/Casper/range/taylor.1.html, accessed July 23, 2023). Livestock numbers in Idaho decreased in the 1950s primarily from loss of large sheep operations (indicated by changes in authorized use for grazing; fig. 1). Livestock numbers have fluctuated at or below this initial decrease through the remainder of the 1900s, with a steady conversion from sheep to cattle. In the last decade, a substantial decrease in authorized use on Bureau of Land Management (BLM) lands in Idaho has been recorded (fig. 1).

An important factor contributing to an increase in wildfires includes the expansion of cheatgrass (D’Antonio and Vitousek, 1992). Of the nearly 98 million acres of BLM lands in Idaho, Nevada, Oregon, Utah, and Washington, 17.3 million acres are believed to have at least 10 percent of the plant biomass composed of annual grasses, including cheatgrass or medusahead (Pellant and Hall, 1994). These annual grasses create fine-fuel loads that increase the probability of fire starts and the rate of fire spread in areas they dominate (Brooks and Pyke, 2001). …

The Murphy Wildland Fire Complex

On July 16 and 17, 2007, a series of wildland fires were ignited by lightning in rangelands near the Idaho-Nevada border southwest of Twin Falls, Idaho. The Rowland Fire (initiated west of Murphy Hot Springs, Idaho) and Elk Mountain Fire (initiated southeast of Three Creeks, Idaho) grew together and became known as the Murphy Wildland Fire Complex (fig. 2). The Scott Creek Fire (west of Jackpot, Nevada) also was ignited by lightning on July 17 and was later designated as part of the Murphy Wildland Fire Complex. Some of the fires in this complex burned for more than two weeks, and the complex was fully contained by August 2, 2007. This complex of fires burned across portions of three BLM FOs (Jarbidge, Bruneau, and Elko), portions of the Humboldt-Toiyabe National Forest, about 48 sections of land managed by the State of Idaho, and extensive stretches of private lands. A total of 652,016 acres was encompassed by this fire complex (NIFC data: http://www.nifc.gov).

These wildfires had tremendous impacts on the sagebrush steppe ecosystems of south-central Idaho and a portion of north-central Nevada. Seasonal and year-long habitats were altered for sage-grouse, mule deer, elk, bighorn sheep, pronghorn, Brewer’s sparrow, sage sparrow, other sagebrush-obligate birds, and many other wildlife species that use these rangelands. Severe impacts also were exacted on forage resources for livestock, cultural resource values, and watershed health and stability as a result of these fires. The ecological impacts of this fire will take several years to be fully realized and will vary depending on weather conditions in the coming years.

In the last three decades, several wildfires have occurred in the area that burned in the Murphy Wildland Fire Complex. Many of these burned areas were revegetated with perennial grasses, including both introduced and native species. Records from the Jarbidge Field Office (FO) of the BLM indicate that about 402,000 acres were seeded through the end of 2006. This number of acres represents 26 percent of the total public lands in the Jarbidge FO. Some land managers and livestock operators speculated that extensive seedings of perennial grasses following wildfires, without commensurate increases in livestock grazing, contributed to an increase in herbaceous production. The speculation in turn, considered the possibility that increased herbaceous production provided additional fuels for wildfire.

Purpose and Scope

In August 2007, a team3 of scientists, habitat specialists, and land managers was called together by Tom Dyer, Idaho BLM State Director, to examine initial information from the Murphy Wildland Fire Complex in relation to plant communities and livestock grazing patterns. This report is the result, which is presented to meet the following objectives:

Provide preliminary observations and recommendations regarding the effects, if any, of existing plant community composition (native rangeland and crested wheatgrass seedings) and current management of livestock grazing on fire behavior and rate of spread of the Murphy Complex Fires. Historical or potential vegetation composition, because it may have been influenced by historical livestock grazing levels or practices is, by necessity, background information and not the focus of this report.

Provide recommendations for long-term research or studies needed to address issues or remaining questions surrounding the use of livestock to reduce fuels while maintaining post-fire resource values in the area encompassed by the Murphy Wildland Fire Complex.

Discuss the potential application of the findings gleaned from the Murphy Wildland Fire Complex to other areas from a “lessons learned” perspective. …

This report focuses on the potential role that livestock grazing played in altering fuel loads and fuel types that affected the pattern and severity of fires in the Murphy Wildland Fire Complex. Because fire behavior, fire extent, and level of vegetation consumed result from many interacting factors, the specific role that grazing had on the fires was difficult to ascertain. The team preparing this report toured the area of the Murphy Wildland Fire Complex on August 28, 2023 and saw first-hand examples of completely burned areas, patchily burned mosaics, and contrasts where fires stopped at a fence-line or only fingered into the adjacent pasture. A reasonable explanation for these contrasts was a difference in the grazing management between the areas on each side of the fence-line (fig. 8).

Livestock operators in the area shared their knowledge of the pre-burn vegetation conditions, levels of grazing use, and on-site observations of fire behavior with the report team. These observations supported the possibility that livestock grazing resulted in a mosaic burn or observable fence-line contrasts that could be attributed to differences in utilization levels created by livestock grazing.

Major Findings and Lessons Learned

Much of the Murphy Fire Complex burned under extreme fuel and weather conditions. Weather conditions in the first four to five days of the fire were particularly dry, hot, and windy. It was during this period that between 75 and 90 percent of the total area burned. As confirmed by fire modeling, these extreme conditions likely overshadowed (or swamped) livestock grazing as a factor influencing fire extent and fuel consumption in many areas where these fires burned.

Level of fuels consumed (or burn severity) was affected mostly by the plant communities that existed on a site before fire (that is, shrubland communities can potentially experience a greater loss of biomass and vegetative structure than grasslands yielding higher burn severity values). Our study of fuel consumption and our field examination confirm that all vegetation types experienced a range of fuel consumption, including many acres in the low burn severity class, indicating patchy burning patterns or incomplete consumption of fuels. Greater proportions of plant communities characterized as grasslands were categorized in the low burn severity class than shrublands. This observation confirms that fuel consumption (or burn severity) is largely influenced by the kind of plant biomass and structure that exists before the fire.

There were many abrupt contrasts in fuel consumption (or, burn severity) primarily attributed to abrupt changes in vegetation type, such as a transition from seeded grasslands to shrubland communities. Burn severity contrasts throughout the Murphy Wildland Fire Complex were most strongly aligned with amount of shrub cover, current year’s biomass, and vegetation type. A few abrupt contrasts in burn severity coincided with apparent differences in actual use by livestock and other grazing factors, as illustrated by fence-line contrasts.

Potential effects for livestock grazing to reduce fuel and affect fire behavior were dependent on the vegetation type. Fire behavior in sagebrush vegetation types is driven by sagebrush cover and height, with the herbaceous component on which livestock focus their grazing, playing a lesser role. Consequently, opportunities to influence fire behavior through livestock grazing are greatest in grassland vegetation types. Fire modeling suggests grazing in grassland vegetation can reduce surface rate of spread and fire line intensity to a greater extent than in shrubland types where woody fuels generally are not reduced by cattle or sheep grazing.

Herbaceous biomass produced during one year and persisting into the next growing season contributes to the dead fine fuel load (that is, 1-htl fuels) in subsequent years. Livestock grazing that reduces the carryover of dead fuels from one year to the next can influence fire behavior, particularly under less intense fire conditions.

The potential effects of grazing on fire behavior are highly dependent on weather, fuel load, and fuel-moisture conditions. Extensive fires, such as those of the Murphy Wildland Fire Complex, generally result from a combination of many factors but are largely weather driven. Under such extreme conditions, grazing applied at sustainable utilization levels would have limited or negligible effects on the fire behavior. When weather and fuel moisture conditions are less extreme, grazing may reduce the rate of spread and intensity of fires allowing for more patchy burns with lower fuel consumption levels.

7 Apr 2008, 5:53pm
Ecology Management
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Montane Meadow and Open Area Encroachment in the Lincoln Forest, Sacramento Grazing Allotment

Frost, Ric, Casey Roberts, Garrett Hyatt, John Fowler. 2007. Montane Meadow and Open Area Encroachment in the Lincoln Forest, Sacramento Grazing Allotment. New Mexico State Univ. Cooperative Extension Service/Agricultural Experiment Station, Range Improvement Task Force, Report 69.

Full text [here] (12,952 KB)

and

Frost, Ric. 2007. Just One Match - An Easy Way To Destroy New Mexico. Range Magazine, Spring 2007.

Full text [here] (329 KB)

The second paper is a “popular” version of the first for lay readers, although both are very good and not too technical for most people.

Selected excerpts from “Just One Match“:

It is amazing how much fire one match can cause. Back in the year 2000, one match ignited the infamous Cerro Grande fire by Los Alamos, N.M. This same fire “ignited” an indepth study of Southwestern forest conditions by the state university. This report reveals that the Cerro Grande, Scott-Able, Viveash and several other fires on government lands that same season destroyed approximately 689 square miles of habitat in New Mexico.

The report points out that the intensity of the catastrophic habitat-destroying fires was a direct result of the fuel-load biomass levels created by the Mexican spotted owl environmental lawsuit. Logging restrictions were imposed on government-controlled lands. The study reveals that U.S. Forest Service-controlled lands in New Mexico forests alone had accumulated approximately 1.4 billion board feet of fuel-load biomass buildup between the years 1986 to 1999, as logging declined 82.4 percent during the same period. …

All of the Mexican spotted owl habitat in the Los Alamos area and the owl-nesting protected locations were lost, as were many of the ground-dwelling endangered species. Other endangered and protected habitat areas were also seriously compromised or destroyed by these fires.

The report also points out the loss of an entire cultural timber-harvesting infrastructure due to owl restrictions and the resulting loss of the economic sector to rural communities in the hundreds of millions of dollars. This is in addition to the costs of fire fighting, the personal costs and loss of homes (including the threat to the Los Alamos nuclear facilities in the path of the Cerro Grande fire), as well as the human lives lost as a result of these fires. It is doubtful that the families who lost everything were concerned over the the loss of a few birds.
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20 Feb 2008, 5:04pm
Ecology
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Late Succession Is Eco-Babble Nonsense

by Mike Dubrasich

The horrendous megafires that are punishing our landscapes arise in what many call “late successional stands”. Government vegetation maps indicate that the most fire-prone areas are designated late successional. The government has incorporated the term late successional into our legal system. It is a land use class, much as commercial, industrial, or residential zones are designated on urban zoning maps.

Many forest scientists maintain that late succession is some sort of ecological state or condition. And not just any condition; late succession is the cat’s meow, the most treasured condition that forests can attain. We have shut down and locked up tens of millions of acres of our public forests because they are or soon will be (we hope) late successional. Nobody talks about old-growth anymore; the term of art is late successional.

It therefore behooves us to try to figure out what the heck “forest succession” is and when it becomes “late.”

But that is a fool’s errand, because forest succession is itself a bogus concept.

Ideally, in the eco-babble dream world, forests begin as bare ground, totally seared to the dirt, with nothing alive above ground. First “pioneer” plant species move in, followed by “settler” species, and eventually “climax” species take over.

That’s succession, a gradual change in species, particularly tree species, until a stable, “climax community” of plants is established and sets there, unchanged, for the rest of time.

It is similar to the succession of kings to a throne. The first king named Henry is Henry I. When he dies, another king succeeds him. And then that king dies, and somebody else succeeds him. Eventually, if enough time passes, you might see another King Henry, and then another, all the way up to Henry the Eighth or even more. Of course, no king lives forever, so no climax stable kinghood ever comes about.

That’s true in nature, too, obviously. No tree lives forever. The theory of forest succession accounts for that: the individual trees may die, but the species eventually stop changing, and that is the climax state. Of course, eventually and inevitably another disturbance occurs, and then the whole successional parade starts over.

The problem with the theory of forest succession is that it does not occur in nature. It is a phenomenon that occurs only in the minds of dreamers. The real world is quite different than that.

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12 Dec 2007, 1:28pm
Ecology
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Historical Fire Cycles in the Canadian Rocky Mountain Parks

Van Wagner, Charles E., Mark A. Finney, and Mark Heathcott. Historical Fire Cycles in the Canadian Rocky Mountain Parks. Forest Science 52(6) 2006, (704-717).

Charles E. Van Wagner, Canadian Forest Service (ret.), Mark A. Finney, USDA Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, and Mark Heathcott, Parks Canada.

Full text [here]

Review by Mike Dubrasich

A remarkable and historic forest science paper was published last December in Forest Science, the leading US scientific journal about forest science. The paper is remarkable for a half dozen or more reasons, and in this essay we (attempt to) sort them out and explain them.

First, the authors are the cream of the crop. Charles E. Van Wagner is the unofficial dean of Canadian fire science. No one has advanced the science more, up there and few down here, during his lifetime. Finney and Heathcott are equally experienced grey beards of fire ecology. Hidden from direct view are dozens of field and laboratory researchers who contributed to the data collection for this paper, over a period of more than two decades.

Previous accounts of data collection and fire history have been published for all seven parks, some more than once. Jasper fire scar data were studied by Tande (1979a, b) but no formal reference exists for the whole-park age-class survey of 1987 to 1990. These data are on file at Jasper National Park; sampling work was begun by B. Wallace and G. Fenton, completed and mapped by S. Cornelsen, and finally compiled by R. Kubian. Fire history and age-class data for Banff National Park were reported by White (1985), Rogeau and Gilbride (1994), and Rogeau (1996); for Kootenay National Park by Masters (1990); for Yoho National Park by Tymstra (1991); for Peter Loughheed (formerly Kananaskis) Provincial Park of Alberta by Hawkes (1979, 1980), Johnson (1987), Johnson and Fryer (1987), and Johnson and Larsen (1991); for Mount Assiniboine and Spray Lakes Provincial Parks of Alberta by Rogeau (1994 a, b).

In addition, the authors acknowledge “Parks Canada for providing the data, and Ian Pengelly, Cliff White, and Stephen Woodley, all of Parks Canada, for helpful comment and interest.”

Historical Fire Cycles in the Canadian Rocky Mountain Parks is about the fire history of seven contiguous national and provincial parks in the Canadian Rockies. They include Banff, Jasper, Kootenay, and others. Their combined total area is 21,900 sq. km., or 13,600 sq. miles. Of those, 6,300 sq. miles are forest, and the rest are rock, ice, water, or treeless vegetation.

No matter what units are used, that is a very large chunk of forest for a study, and one of the paper’s remarkable features. Another is that the study took over twenty years to complete and is the work of dozens of researchers. Another is that the fire dates they discovered go back to 1280 AD. To my knowledge, no other fire study has ever come close to the breadth of acreage and time comparable to Historical Fire Cycles in the Canadian Rocky Mountain Parks.

Another remarkable feature is the principal finding of the study. Historically, forest fires in the Canadian Rockies have not been controlled by climate or random chance. Van Wagner et al. disproved those hypotheses, with an intensive yet elegant work of deductive science.

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11 Dec 2007, 7:10pm
Ecology Management
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Burning Banff

By Stephen J. Pyne

Originally published in Interdisciplinary Studies in Literature and the Environment 11.2 (Summer 2004) [here] by the Association for the Study of Literature and the Environment.

Full text [here]

Selected excerpts:

There are five of us, plus three pack horses, and we are strung along a trail that threads into Banff National Park. Banff is to the Rocky Mountains what the Grand Canyon is to the Colorado Plateau. A packtrip through its knotted peaks is the equivalent of a float trip down the Colorado River. We enter the park along the Red Deer River in the northeast.

Its critics dismiss Banff as a trash park-savaged by transcontinental highways and a railroad, the Bow Valley in particular deflowered by golf courses, ski resorts, swarms of tourists, a hydropower dam, its landscape degraded beyond redemption. In the mid-1990s Banff was even threatened with delisting as a World Heritage Site. Its defenders, however, note that the park has preserved nearly all its biotic pieces and holds intact its majestic matrix of streams, forests, storms, and slashing peaks. It yet retains its grizzlies, wolves, mountain lions; its elk, moose, bighorn sheep, mountain goats; a monumental megafauna to match its monumental scenery. Most spectacularly, nearly alone among Canadian parks, and rarely for North America, Banff has nurtured a habitat for free-burning fire.

A pack trip is thus a traverse through some of the most interesting fire management in North America. Banff is Canada’s first national park; a century later it had become for Parks Canada the flagship for an aggressive policy of ecological integrity for which free-burning fire was the vital spark. Ecological integrity aims to keep all the parts and processes of a biota and to grant them a suitable structure so that they can maintain themselves indefinitely. It contrasts with other preservationist philosophies by ignoring such standards as naturalness, wilderness, or historical authenticity, which may or may not contribute to the perpetuation of species and how they live. A policy such as Banff’s is, as postmodernists like to mutter, a contested matter.

All the themes are here: Banff is where they arose and where the relevant ideas took to the field to decide the issue. That makes Banff typical, or prototypical. What makes it special is that ecological integrity can apply to any landscape; at Banff it applies to an extraordinary menagerie of big animals and the habitats that sustain them. Fire matters because fire seems to be essential to those habitats. Ecological integrity may only succeed if Banff burns. The trick is to see that it burns properly. And that is the purpose for this curious expedition, an intellectual inspection…

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