“Early View” is like Christmas!

I’m extremely happy to say that the following papers are now out in early view – the first two papers are the results of Eryn Schineder’s and Kyle Rodman’s thesis work. For those who may not know, Eryn’s work focused on spatial patterns and reference conditions at the Barney Springs site south of Flagstaff, a pure ponderosa pine site on limestone soils that has managed to avoid being harvested. Truly a unique system to study… Kyle’s work also focused on spatial patterns and reference conditions, but in dry mixed-conifer sites along the Mogollon Rim. He presents a variety of reference attributes that will be interesting and applicable to many of you currently working in dry mixed-conifer forests (especially this findings regarding long-term changes in species composition). I’m am really proud of these two and both works are significant contributions to our knowledge regarding HRV and long-term vegetation dynamics. In case you’re wondering, Eryn and Kyle are both currently pursuing PhDs – Eryn with Andrew Larson at Univ. of Montana and Kyle at Univ. of Colorado at Boulder with Tom Veblen.

Lastly, the third paper presents an idea that Daniel Laughlin, Rob Strahan, Dave Huffman and I have been developing for a while now. In this paper we present a functional (species trait-based) approach to restoring resilient ecosystems in light of changing environmental conditions and explore it’s application in dry mixed-conifer forests (study sites at Black Mesa and on the north rim of Grand Canyon NP). Really exciting work that I’m happy to have been a part of!!!

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It’s been a productive year thus far…

I’ve been out of pocket for awhile on this blog, but it’s fir a good reason. I’ve been writing my butt off! Below are four manuscripts published in the last few months, all of which I was a part of… I’ll like the work speak for itself.

Taylor The Economics of Ecological Restoration and Hazardous Fuel Reduction Treatments in the Ponderosa Pine Forest Ecosystem
by M H Taylor, A J Sanchez Meador, Y S Kim, K Rollins, and H Will
Abstract: In this article, we develop a simulation model of the benefits and costs of managing the ponderosa pine forest ecosystem in the southwestern United States. Using the model, we evaluate and compare the economic benefits and costs of ecological restoration and hazardous fuel reduction treatments. Both treatment approaches increase the expected number of low-severity wildfires, which can promote postfire rehabilitation. Hazardous fuel reduction treatments are likely to reduce expected wildfire suppression costs, but not enough to offset the costs of implementing treatments. Conversely, ecological restoration treatments do not necessarily reduce expected wild-fire suppression costs but fully restore the ecosystem in more than half of the simulation runs, which lowers the need for future fire suppression and reduces the chance of conversion to nonforest, alternative stable states. We find that the choice between hazardous fuel reduction and ecological treatments will depend on the management objective being pursued, as well as on site-specific factors such as the wildfire return interval and the economic value of biomass removed.
 Stoddard Five-year post-restoration conditions and simulated climate-change trajectories in a warm/dry mixed-conifer forest, southwestern Colorado, USA
by M T Stoddard, A J Sánchez Meador, P Z Fulé, and J E Korb
Abstract: Some warm/dry mixed-conifer forests are at increasing risk of uncharacteristically large, high-severity fires. As a result, managers have begun ecological restoration efforts using treatments such as mechanical thinning and prescribed fire. Empirical information on the long-term impacts of these treatments is limited, especially in light of potential climate change. We assessed changes in forest structure and composition five-years following three alternative restoration treatments in a warm/dry mixed-conifer forest: (1) thin/burn, (2) prescribe burn, and (3) control. We used the Climate-Forest Vegetation Simulator (Climate-FVS) model to quantify potential forest trajectories under alternative climate scenarios. Five years following treatments, changes in forest structure were similar to initial post-treatment conditions, with thin/burn being the only treatment to shift and maintain forest structure and composition within historical reference conditions. By 2013, the thin/burn had reduced basal area (11.3 m2 ha-1) and tree density (117.2 tree ha-1) by 56% and 79% respectively, compared to pre-treatment values. In the burn, basal area (20.5 m2 ha-1) and tree density (316.6 tree ha-1) was reduced by 20% and 35% respectively, from 2002 to 2013. Mortality of large ponderosa pine trees (the most fire-resistant species) throughout the duration of the experiment, averaged 6% in the burn compared to 16% in the thin/burn treatment. Changes five years following treatments were largely due to increases in sprouting species. Shrub and sapling densities were approximately two to three times higher (respectively) in the thin/burn compared to burn and control and dominated by sprouting oak and aspen. Under climate simulations, the thin/burn was more resilient in maintaining forest conditions compared to burn and control which approached meager forest conditions (3–4 m2 ha-1). These results indicate that restoration treatment that include both thinning and burning can maintain forest integrity over the next few decades.
 Tuten Ecological restoration and fine-scale forest structure regulation in southwestern ponderosa pine forests
by M C. Tuten, A J Sánchez Meador, and P Z. Fulé
Abstract: Fine-scale forest patterns are an important component of forest ecosystem complexity and spatial pattern objectives are an increasingly common component of contemporary silviculture prescriptions in dry fire-adapted forests of North America. Despite their importance, questions remain regarding the assessment of silvicultural treatments designed to meet spatial objectives. We initiated a replicated silvicultural assessment of two forest management approaches commonly applied in dense ponderosa pine forests of the Southwest United States: historical evidence-based ecological restoration guidelines (ERG) and northern goshawk (Accipiter gentilis) foraging area management recommendations (GMR). We compared stand-level characteristics, global tree location point patterns and tree group-level attributes resulting from the marking of these approaches to current forest conditions and patterns of historical forest remnants in six, 2.02 ha stem mapped plots. We also assessed group-level Vegetative Structural Stage (VSS; a classification of fine-scale forest structural development used to regulate fine-scale spatial patterns in these forests). ERG and GMR-based treatments significantly reduced densities and basal area from the current condition, but did not significantly differ in density from historical forest remnant estimates. GMR-based treatments retained greater stand level basal area than ERG-based treatments, primarily in large, 28–48 cm tree diameter classes. GMR-based treatments approximated global tree location point patterns of forest remnants better than ERG-based treatments, primarily due to a 5–6 m minimum spacing of residual trees, but also likely due to specific aspects of ERG-based marking techniques. Despite this difference, both treatments resulted in group-level characteristics similar to those exhibited by historical forest remnants. Both treatments significantly altered group-level VSS area and reduced variation of tree diameters within classified VSS groups.
 Outzs Post-fire ponderosa pine regeneration with and without planting in Arizona and New Mexico
by J Ouzts, T Kolb, D Huffman, A J Sánchez Meador
Abstract: Forest fires are increasing in size and severity globally, yet the roles of natural and artificial regeneration in promoting forest recovery are poorly understood. Post-fire regeneration of ponderosa pine (Pinus ponderosa, Lawson and C. Lawson) in the southwestern U.S. is slow, episodic, and difficult to predict. Planting of ponderosa pine after wildfire may accelerate reforestation, but little is known about survival of plantings and the amount of post-fire natural regeneration. We compared ponderosa pine regeneration between paired planted and unplanted plots at eight sites in Arizona and New Mexico that recently (2002– 2005) burned severely. Two sites had no natural regeneration and no survival of planted seedlings. Seedling presence increased with number of years since burning across all plots, was positively associated with forb and litter cover on planted plots, and was positively associated with litter cover on unplanted plots. Survival of planted seedlings, measured five to eight years after planting, averaged 25% (SE = 8) and varied from 0% to 70% across sites resulting in seedling densities of 0–521 trees ha-1. Based on a projected 44% survival of seedlings to mature trees and target density of mature trees determined by historical range of variability and ecological restoration principles, four of eight sites have a seedling density in planted plots (125–240 ha-1) that will produce a density of mature trees (55–106 ha-1) close to desired levels, whereas seedlings are currently deficient at three planted sites, and in surplus at one site, which had abundant natural regeneration. Natural regeneration in unplanted plots during the first decade after burning produced seedling densities inconsistent with desired numbers of mature trees. Natural regeneration in unplanted plots produced less than 33 seedlings ha-1 at seven of eight sites, but produced 1433 seedlings ha-1 at one high-elevation site that supported a more mesic vegetation community before burning than the other sites. Our results show that current practices for planting ponderosa pine after severe fires in Arizona and New Mexico produce desired numbers of seedlings in approximately half of all projects, whereas natural regeneration rarely does within the first decade after burning.

 

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A couple of new wildfire-related publications

Over the past year I have had the opportunity to work a several wildfire-related projects, two of which are now available from their publishers. The first focuses on the effectiveness of fuel treatments following the Wallow  (2011) fire and the second focuses on long-term forest dynamics under alternative climate and management scenarios following the Rodeo-Chediski (2002) fire. These were both great projects and I think collectively they provide quite a bit of insight into the abilities of managers and agencies to mitigate wildfire effects (during and after) and highlight the effects treatments have on resiliency and given different climate scenarios.

Screenshot 2014-10-02 07.12.24 Amy E. M. Waltz, Michael T. Stoddard, Elizabeth L. Kalies, Judith D. Springer, David W. Huffman, and A.J. Sánchez Meador. 2014. Effectiveness of fuel reduction treatments: assessing metrics of forest resiliency and wildfire severity after the Wallow Fire, AZ. Forest Ecology and Management 334(15): 43-52. http://dx.doi.org/10.1016/j.foreco.2014.08.026

Abstract: Landscape-scale wildfire has occurred in higher frequencies across the planet. Fuel reduction treatments to fire-adapted systems have been shown to reduce the impact to human values-at-risk. However, few studies have examined if these treatments contribute to ecosystem resilience, or the capacity of a system to absorb perturbation and return to a similar set of structures or processes. We defined short-term metrics of resiliency to test the hypothesis that fuel reduction treatments in mixed conifer forests increased a fire-adapted system’s resiliency to uncharacteristically severe wildfire. In addition, we tested the hypothesis that fuel reduction treatments reduced burn severity, thereby increasing protection for adjacent human communities. We examined a mixed conifer forested landscape in the southwestern U.S. that was burned by a landscape-scale “mega-fire” in 2011; fuel reduction treatments had been established around communities in the 10 years prior to the fire. Fire effects were highly variable in both treated and untreated forests. However, analysis of resiliency metrics showed that: (a) treated units retained a higher proportion of large trees and had post-fire tree densities within the natural range of variability; (b) the understory herbaceous community had significantly higher cover of native grasses in the treated units, but no significant differences in nonnative cover between treated and untreated units; and (c) high-severity patch sizes were significantly larger in untreated stands and covered a larger proportion of the landscape than historical reference conditions. Fire severity, as defined by overstory mortality and basal area loss, was significantly lower in treated units; on average, trees killed per hectare in untreated units was six times the number of trees killed in treated units. Fuel reduction treatments simultaneously reduced fire severity and enhanced short-term metrics of ecosystem resiliency to uncharacteristically severe fire.

 Screenshot 2014-10-02 07.12.15 Alicia Azpeleta Tarancón, Peter Z. Fulé, Kristen L. Shive, Carolyn H. Sieg, Andrew Sánchez Meador, and Barbara Strom 2014. Simulating post-wildfire forest trajectories under alternative climate and management scenarios. Ecological Applications 24:1626–1637. http://dx.doi.org/10.1890/13-1787.1

Abstract: Post-fire predictions of forest recovery under future climate change and management actions are necessary for forest managers to make decisions about treatments. We applied the Climate-Forest Vegetation Simulator (Climate-FVS), a new version of a widely used forest management model, to compare alternative climate and management scenarios in a severely burned multispecies forest of Arizona, USA. The incorporation of seven combinations of General Circulation Models (GCM) and emissions scenarios altered long-term (100 years) predictions of future forest condition compared to a No Climate Change (NCC) scenario, which forecast a gradual increase to high levels of forest density and carbon stock. In contrast, emissions scenarios that included continued high greenhouse gas releases led to near-complete deforestation by 2111. GCM-emissions scenario combinations that were less severe reduced forest structure and carbon stock relative to NCC. Fuel reduction treatments that had been applied prior to the severe wildfire did have persistent effects, especially under NCC, but were overwhelmed by increasingly severe climate change. We tested six management strategies aimed at sustaining future forests: prescribed burning at 5, 10, or 20-year intervals, thinning 40% or 60% of stand basal area, and no treatment. Severe climate change led to deforestation under all management regimes, but important differences emerged under the moderate scenarios: treatments that included regular prescribed burning fostered low density, wildfire-resistant forests composed of the naturally dominant species, ponderosa pine. Non-fire treatments under moderate climate change were forecast to become dense and susceptible to severe wildfire, with a shift to dominance by sprouting species. Current U.S. forest management requires modeling of future scenarios but does not mandate consideration of climate change effects. However, this study showed substantial differences in model outputs depending on climate and management actions. Managers should incorporate climate change into the process of analyzing the environmental effects of alternative actions.

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The Culmination of a Multi-year Collaborative Effort

1000343_10201990475388401_2134217229_nThe image to the left is of RMRS-GTR-310. For me, this manuscript is the culmination of a multi-year collaborative effort with the USFS Southwestern Region and RMRS intended to provide land managers with a better understanding of forest structure, composition, and processes as they analyze and make decisions about restoration of frequent-fire forests. The document synthesizes relevant forest science, provides implementation suggestions, and communicates the broad range of benefits associated with the restoration of frequent-fire forests.

Citation:
Reynolds, Richard T.; Sánchez Meador, Andrew J.; Youtz, James A.; Nicolet, Tessa; Matonis, Megan S.; Jackson, Patrick L.; DeLorenzo, Donald G.; Graves, Andrew D. 2013. Restoring composition and structure in Southwestern frequent-fire forests: A science-based framework for improving ecosystem resiliency. Gen. Tech. Rep. RMRS-GTR-310. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 76 p. Download

 Abstract:
Ponderosa pine and dry mixed-conifer forests in the Southwest United States are experiencing, or have become increasingly susceptible to, large-scale severe wildfire, insect, and disease episodes resulting in altered plant and animal demographics, reduced productivity and biodiversity, and impaired ecosystem processes and functions. We present a management framework based on a synthesis of science on forest ecology and management, reference conditions, and lessons learned during implementations of our restoration framework. Our framework focuses on the restoration of key elements similar to the historical composition and structure of vegetation in these forests: (1) species composition; (2) groups of trees; (3) scattered individual trees; (4) grass-forb-shrub interspaces; (5) snags, logs, and woody debris; and (6) variation in the arrangements of these elements in space and time. Our framework informs management strategies that can improve the resiliency of frequent-fire forests and facilitate the resumption of characteristic ecosystem processes and functions by restoring the composition, structure, and spatial patterns of vegetation. We believe restoration of key compositional and structural elements on a per-site basis will restore resiliency of frequent-fire forests in the Southwest, and thereby position them to better resist, and adapt to, future disturbances and climates.

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Continued Scounting of Mixed-Conifer Forests along the Mogollon Rim, AZ

DSC_0040Friday of this past week we (myself, one of my graduate students, members of the ERI Outreach Staff and a Forest Service representative) spent the day scouting potential research sites along the Mogollon Rim, in the mixed-conifer forest type. These forests generally occur at elevations between 8000 to 10,000 feet and under natural conditions, their higher site productivity and open structure facilitates leads to a more diverse (as compared to pondersa pine) understory.

Depending on location and often aspect, Douglas-fir, white fir, blue spruce, and southwestern white pine will dominate the tree canopy, often with ponderosa pine clearly dominating on warmer slopes. Quaking aspen, bigtooth maple, and Gambel oak are also prominent in these forests. Fire histories in mixed-conifer forests vary with forest composition, landscape characteristics and human intervention, but have been shown to be mainly frequent surface fires to infrequent, patchy (yet small) crown fires with return intervals averaging around 10-15 years.

If all goes as planned (when does it?), this could be the location of a new LEARN site!

DSC_0063 DSC_0057 DSC_0043 DSC_0025 DSC_0087 DSC_0047

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Tree-Ring Chronologies and Mixed Conifer – Chocolate and Peanut Butter?

Rplot
Last week I allowed myself a few moments of respite and managed to develop a standard tree RWI (ring with index) chronology (and resulting residuals) for the Black Mesa site near Payson, AZ. I used dplR and R and the expreience was awesome. Beginning to end, the whole exercise took maybe 10-15 minutes, and thta includes figureing what format best fit our data. The resulting figure(s) show a smoothing spline (red) to highlight high-frequency (decadal) variability and the sample depth (dashed) is plotted on the right-hand axis; but the best part is the two harvests (releases evident in 1960s and 1980s) stick out like a sore thumb.

However, now I find myself wondering if these data also happen to capture the recent moratlity (post-2000) event observed throughout western forests and how hard would it be to remove the local climate effect…?

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Mixed-conifer research site on the San Fransisco Peaks, AZ – Site I

DSC_0135_stitch
Over the past two weeks, myself and several ERI staff members were able to establish six one hectare plots in a warm/dry mixed-conifer forest on the southwestern slope of the San Fransisco Peaks, within the boundary of a study area previously examined by Heinlein et al. (2005).

Mixed conifer forests of the American Southwest have been impacted similarly to other conifer forests, yet reference condition information vital to restoration are lacking. This is especially true with respect to spatial patterns, long term dynamics and the influence of site productivity; information critical to informing management decisions. It has been shown that landscape structures such as meadows, discrete tree patches, large trees, and aspen communities have declined as an interlocking understory of shade-tolerant and fire intolerant tree species increased and expanded their ranges, yet the spatial and temporal dynamics associated with these changes are rarely quantified and poorly understood. Our study (Site I of VI in a long-term project) strives to capitalize on existing study sites where fire chronologies have been collected and published, thus allowing for a more complete setting for describing changes in structure and composition.

Overall, this particular site (and the subsequent plot locations) is perfect! The site captures a nice range of contemporary density and species composition, elevation, aspect, and general condition. The site is clearly dominated by ponderosa pine and douglas-fir, but we did encounter quite a bit of large southwestern white pine, aspen, and even a couple of juniper and corkbark fir. Charred evidence and fire scars were everywhere, and the amount of fir and white pine regeneration is impressive…

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