Senior Capstone
Species Regeneration and Timber Stand Management in the Rouge-Siskiyou National Forest Post-Fire
Abstract
This project explores the dynamics of post-fire vegetation regeneration in the Rogue-Siskiyou National Forest, with a specific focus on conifers for timber stand resilience. Investigating three fire-affected areas, the project uses field surveys and data analysis to understand the regeneration patterns of brush, hardwood, and softwood conifer species after high-severity fires. Key plant species, including tanoak (Lithocarpus densiflorus), Douglas fir (Pseudotsuga menziesii), sugar pine (Pinus lambertiana), and others, exhibit diverse responses to fire, providing valuable insights for wildfire and timber stand management. The project revealed that on all sites, hardwood and brush species were thriving, while conifer species were limited in their amount.
Shifting focus to the forest's future, the project addresses climate change impacts based on scholarly articles. Increased wildfire frequency and severity in the Pacific Northwest, driven by warming conditions, pose challenges for conifer-dominated forests. The project emphasizes the potential struggles of conifers in reproducing and competing under evolving climate conditions and increased fires.
Management strategies are explored, with an emphasis on what forest managers can do now and in the future. Insights about the importance of replanting after high-severity burns are discussed. Salvage logging's benefits and potential drawbacks are explored, while site preparation, prescribed burns, and fuel management are identified as critical tools for maintaining robust timber stands.
Invasive species management, ongoing monitoring, and research are highlighted as essential components of adaptive forest management. The project aims to show a comprehensive approach, combining reforestation efforts, sustainable practices, and continuous evaluation to address the complex challenges posed by climate change and wildfires in the Rogue-Siskiyou National Forest.
Table of Contents:
Introduction
The Rogue-Siskiyou National Forest boasts a remarkable diversity of plant species. In my project, I examine the intricate relationship between high-severity wildfires and the regeneration of plant species, especially in the context of cultivating robust timber stands with a focus on conifers. My objective is to study the species that regenerate after a piece of land has been affected by high-severity fires and explore strategies for managing and promoting the growth of robust timber stands.
Understanding which plant species return after a high-severity fire is vital because it provides insights into the resilience and recovery of ecosystems in the face of natural disturbances. High-severity fires can have long-lasting impacts on landscapes, altering both the physical environment and the composition of plant communities. As we continue to face frequent high-severity fires, meticulously documenting the species that reestablish themselves in these post-fire environments provides valuable knowledge on managing these species for the establishment of robust timber stands instead of brush fields. This research contributes to our understanding of ecological processes and can assist in mitigating the ecological consequences of wildfires and supporting the recovery of our natural environments.
This project will help me achieve my goal of becoming a Project Manager for a land use agency in several ways. Through this research endeavor, I am developing essential project management skills, including planning, data collection, analysis, and stakeholder coordination. This project demands meticulous planning and execution, much like the project management processes involved in land use and environmental conservation agencies. I am honing my ability to set clear objectives, manage resources efficiently, and ensure that project timelines are met.
Purpose of the Project
The purpose of my project is to expand understanding into how high-severity wildfires influence plant species regeneration and to develop practical strategies for sustainable forest management, with a focus on timber stands and encouraging conifers to thrive. I examined the fire-prone ecosystem of the Rogue-Siskiyou National Forest.
Scope
My research took place during the fall of 2023, focusing on three locations within the Rogue-Siskiyou National Forest. The Rum Creek Fire of 2022, the Taylor Creek Fire of 2018, and the Big Windy Complex of 2013. The primary goal is to investigate the brush, hardwood, and softwood conifer species that regenerate after a high-severity fire. I evaluate the implications of which species return for timber stand management. I conducted fieldwork in the Rogue-Siskiyou National Forest, collecting data on which species return and species composition in these fire-affected areas. My objective is to gain insight into how wildfires impact the forest plant species and how timber stands can be effectively managed in the face of recurrent high-severity fires.
Methodology
My project involved a combination of field surveys and data analysis. I collected data from three wildfires: the Rum Creek Fire of 2022, the Taylor Creek Fire of 2018, and the Big Windy Complex of 2013. My aim was to observe the vegetation that regenerates at various times after a high-severity fire to understand the trends over time. For each fire, I identified areas that burned at high-severity, considering both aspect and elevation range. To facilitate real-world location identification, I pinpointed a distinguishing feature on the map, visited it in the field, and created fixed-area plots based on 5-acre sections. The general rule is to have one plot for every ten acres, but for more comprehensive data collection, I created two plots every five acres. The chosen plot size for each location is 1/30 of an acre. This size balances the need to capture small regenerating plants while ensuring efficient data collection. I then counted and documented the species that have returned to these plot locations. After data collection, I created graphs for each fire location showing which species returned and the species composition of the plot area. I then compare this data to the species that were traditionally present before frequent fire disturbances; this information can be found in scholarly articles and by observation. By comparing the collected information, I am able to identify trends that may impact future timber stand management. Finally, I conduct research through literature reviews to develop strategies for managing areas that have experienced high-severity fires with the goal of promoting robust timber stands and conifer survival rather than brush and hardwood species only.
Fire Burn Severity Maps for each fire.
Data Collection
On October 16, 2023, I began my data collection at the Big Windy Complex of 2013. My husband and I drove to the site of the fire, having previously identified our desired location based on fire maps. We selected a spot with a west-facing slope that had experienced high-severity burn. Once we were certain we were in the correct location, based on a distinctive bend in the road that was easy to identify, we ventured 66 feet inwards, traveling West.
Once we had reached this distance, we established the plot center using a visible marker. We had a 21.5-foot-long piece of rope. One person stood at the plot center, holding one end of the rope, while the other person extended the rope to its full length, walking in a circle to define the fixed-area plot. The outer boundary of the fixed-area plot was marked with flagging to make it clearly visible. To determine whether a plant was inside or outside the plot, we measured to the center of the plant. If the rope could reach at least the center of the plant, it was considered "in."
Our plots were pre-determined to be 1/30 of an acre in size. We put two plots in a five acre section of high-severity burn. We focused on counting shrubs and tree species. We counted the species using a gridding method. My husband and I walked from the outside of the plot to the inside, systematically covering the plot from top to bottom. We meticulously counted the shrubs and trees we encountered. These were the same methods we used for all six plots.
Plot One and Two of the Big Windy Complex
This was my oldest fire site, and the landscape had undergone significant transformations compared to my youngest site. Notable regeneration was evident, with young Douglas fir (Pseudotsuga menziesii) trees actively contributing to the restoration process. In contrast to my younger fire sites, there were fewer pioneer species like ferns. The terrain exhibited a more diverse and mature vegetation structure, highlighting flourishing fire-adapted shrubs such as tobacco brush (Ceanothus velutinus) and manzanita (Acrtostaphylos). Notably, the most prominent plant was tanoak (Lithocarpus densiflorus), which thrived abundantly and overshadowed many other species on the site. The only conifer species observed were some very young Douglas fir trees, which were noticeably being overshadowed by the hardwood and brush species prevalent in the area.
Plot One Two of the Rum Creek Fire
This was my youngest fire sight, it had been affected by a wildfire in 2022. A year after the incident, the landscape still bore visible scars of a high-severity burn, with blackened trees and an almost desolate atmosphere. Despite this, signs of renewal had started to emerge, particularly in the resilience of certain plant species. I noticed the presence of pioneer species, predominantly grasses and ferns, although it's important to mention that these are not part of my specific focus, which centers on shrubs, hardwood, and softwood conifer species. Simultaneously, after fires its common for invasive species and weeds to begin to establish themselves, potentially reshaping the recovering plant community. Among the returning hardwood species, tanoak stood out as the most prevalent on all plots, accompanied by Pacific madrone (Arbutus menziesii) and bigleaf maple (Acer macrophyllum). It makes sense to observe these species returning early in the recovery process. In subsequent discussions within this project, I delve into a more comprehensive analysis of all species observed on the plots and their relationship with fire. In brief, as I have observed through working in fire and forestry, the species that resprout quickly after a fire, such as those mentioned, have the ability to regenerate typically from their root systems that managed to survive the fire, unlike many conifer species that rely on seeds for regeneration.
Plot One and Two of the Taylor Creek Fire
The last fire I looked at was the Taylor Creek fire. There were not many grass and fern species as observed on my youngest sites. The landscape was still visibly charred with many downed trees that were killed by the fire. Shrubs were very well established, and hardwood tree species like Pacific madrone (Arbutus menziesii) were present. One of the first things that I noticed about this area, even though all three of these fires are really close, is new species emerging. This spot was not dominated so heavily by tanoak. Instead, it was mainly dominated by Pacific madrone and buckbrush (Ceanothus cuneatus). The buckbrush I found to be impressively thick in areas, as will be shown in the photos. Also, a new species of conifer emerged on this fire site; there were several small sugar pines (Pinus lambertiana).
Plants on site's
It is important to have a discussion about which species are coming back and their relationship with fire. This discussion helps us understand why brush and hardwood species are able to colonize and thrive much faster than conifer softwood species. After reading about how these species interact with fire, readers will gain an understanding of all the species found on the sites I looked at. I hope readers will refer back to the graphs after reading the plant descriptions and pay attention to the abundance of brush and hardwood species that have come back versus conifers like Douglas fir. My aim is for readers to gain an understanding that it is much simpler for hardwoods and shrubs to colonize, and in a world where the climate is changing and fires are showing to have increased (Jessica E. Halofsky et al .2020), I predict it will be easier for these species to proliferate compared to conifer species. This, in turn, may make it harder for conifers to adapt.
In all the plots observed, a diverse array of brush, hardwood, and softwood species were identified, each playing a unique role in the context of fire dynamics. The presence of these species and their interactions with fire is crucial for several reasons. Understanding the characteristics and behaviors of brush, hardwood, and softwood species provides valuable insights into the ecological impact of fires on forest ecosystems. Additionally, this discussion is important for informing forest management strategies, especially in regions prone to wildfires.
I have observed through fighting fire that the knowledge of how different species respond to and interact with fire is essential for predicting post-fire vegetation dynamics and the overall resilience of forest ecosystems. It helps land managers make informed decisions about wildfire prevention, preparedness, and recovery efforts. Furthermore, recognizing the relationships between these species and fire contributes to the broader understanding of ecosystem functioning and the intricate balance between different components of the forest community.
Tanoak (Lithocarpus densiflorus):
The most prominent species on many of my sites was the hardwood tree tanoak. Known for its adaptability, proves valuable as it endures through various successional stages, playing a crucial role in several forest ecosystems (S.S. Niemiec et al. 1995). Upon observation, it is evident that tanoak vigorously sprouts after fire or cutting, often establishing dominance over extensive areas. The influence of fire is substantial in shaping the destiny of tanoaks (S.S. Niemiec et al. 1995). Effectively managing stands with tanoak becomes a challenging task, requiring proactive tanoak control to uphold the diversity of conifers, given their typically lower shade tolerance (S.S. Niemiec et al. 1995). Notably, tanoak trees demonstrate slow growth in dense shade, while understory saplings thrive when exposed to increased light. However, there is a risk that overly opening the stands could lead to the decline of larger, co-dominant trees. This concern arises because fire facilitates the thriving of tanoak while simultaneously shading out conifers and other hardwood species (S.S. Niemiec).
Oregon Grape (Mahonia aquifolium):
Oregon grape has various responses to fire. After a low-intensity fire, it can sprout from its root crown or rhizomes, aiding in quick recovery (Ulev, Elena D. 2006). Additionally, its seed production, often in the form of berries, can benefit from fire, as it may stimulate seed germination (Ulev, Elena D. 2006). Oregon Grape is stress-tolerant and can cope with moderate fire events due to its adaptability (Ulev, Elena D. 2006). However, repeated or severe fires may lead to habitat changes and negatively impact this plant's populations and the ecosystems it calls home (Ulev, Elena D. 2006).
Golden Chinquapin (Chrysolepis chrysophylla):
Golden chinquapin displays a variable response to fire severity (Meyer, Rachelle. 2012). In some cases, it thrives following severe fires in shrub and mixed-conifer ecosystems, especially in regions like central and southern Oregon (Meyer, Rachelle. 2012), the exact area that I am studying. It can even thrive in areas with exposed mineral soil, indicating that after a high-fire severity fire it can establish quickly (Meyer, Rachelle. 2012). However, there is evidence suggesting that increased fire severity may be detrimental to giant chinquapin, particularly in chaparral fires where it may not sprout (Meyer, Rachelle. 2012). The plant's survival and recovery after prescribed fires also vary, with low-severity fires having a milder impact than moderate-severity ones (Meyer, Rachelle. 2012). It possesses fire-adapted traits, including fire-resistant bark and a sprouting ability, and can rely on fire for seed release (Meyer, Rachelle. 2012). Fire-induced habitat changes can create opportunities for giant chinquapin to thrive, particularly in ecosystems where it competes effectively with less fire-adapted plants. In some cases, giant chinquapin may increase to the point of becoming problematic for forest regeneration following severe disturbances (Meyer, Rachelle. 2012)
Pacific Madrone (Arbutus menziesii):
In a study conducted by Emily Newbury in 2019, the impact of fire on the Pacific madrone is revealed to be intricate, influenced by a range of factors. In the aftermath of a fire disturbance, there is a notable increase in the mean number of smaller resprouts (less than one centimeter in diameter), indicating robust regrowth (Emily Newbury et al. 2019). However, it is observed that burned areas tend to exhibit fewer larger resprouts (3-4.9 cm and over 5 cm) compared to areas subjected to thinning alone (Emily Newbury et al. 2019). Furthermore, the tallest resprouts in burned areas, on average, are shorter than those in thinned areas (Emily Newbury et al. 2019). This suggests that while Pacific madrone can regenerate and display new growth after a fire event, the resprouting pattern differs, characterized by a prevalence of smaller resprouts and a reduction in larger ones (Emily Newbury et al. 2019). In the sites that I collected data, I found Pacific madrone to be thriving from resprouts in all plots.
Douglas Fir (Pseudotsuga menziesii):
In an article by the National Park Service (NPS) from 2023, Douglas-fir is described as having a nuanced relationship with fire. While it can survive without fire, older trees possess thick bark, providing resilience against low to medium-intensity fires (NPS. 2023). However as I observed, high-intensity fires can be fatal to Douglas-fir of any age. The species' lightweight, winged seeds allow for wind dispersal, facilitating regeneration in new locations after a fire (NPS. 2023). Douglas-fir encounters challenges in regenerating in the shade of an established forest, particularly in comparison to shade-tolerant species like western hemlock (NPS. 2023). As I observed Douglas-fir is much smaller in areas where it is being shaded by brush and hardwood species. Consequently, in older Douglas-fir forests, there is a succession pattern where young western hemlock trees replace aging Douglas-fir, unless high-intensity fires create openings for Douglas-fir seedlings (NPS. 2023). Low-intensity fires maintain the existing forest composition, while severe crown fires clear the forest, providing opportunities for new Douglas-fir growth (NPS. 2023). Moreover, fire in Douglas-fir communities serves the beneficial role of controlling root rot fungi, as fire can sterilize the soil and eliminate these pathogens (NPS. 2023).
Whiteleaf Manzanita (Arctostaphylos viscida):
Whiteleaf manzanita relies on obligate seeding as a key adaptation to fire. Manzanita seeds are dormant and germinate readily after fire breaks seed dormancy (Leia Althauser. 2019). Its abundant seeds, protected by dense carpellary tissues, persist in the soil seed bank and readily germinate post-fire (Leia Althauser. 2019). Described as a "fire-recruiter," Whiteleaf manzanita exhibits seedling establishment primarily in the first season after a fire (Leia Althauser. 2019). As observed following a fire, Whiteleaf manzanita shows increased density. The species is integral to various fire regimes in chaparral, woodlands, and forests, with historical fire-return intervals ranging from infrequent stand-replacement crown fires to frequent low-severity surface fires (Leia Althauser. 2019). Fire management considerations emphasize the importance of fire for Whiteleaf manzanita's germination and seedling establishment, and alterations in fire frequency may impact its persistence (Leia Althauser. 2019).
Greenleaf Manzanita (Arctostaphylos patula):
Fire ecology is integral to the life cycle of Greenleaf manzanita (Hauser, A. Scott. 2007). This species establishes itself after a fire through both seed germination and, in certain populations, sprouting from the lignotuber (Hauser, A. Scott. 2007). A lignotuber is a woody swelling or structure found at or below ground level (Hauser, A. Scott. 2007). This specialized structure serves as a storage organ, containing buds and nutrients, allowing the plant to regenerate or resprout after disturbances such as fire, cutting, or adverse environmental conditions (Hauser, A. Scott. 2007). The dormancy of Greenleaf manzanita seeds is broken by fire scarification, a critical process for successful germination (Hauser, A. Scott. 2007). The physical and chemical characteristics of Greenleaf manzanita make it highly flammable, potentially serving as an adaptive trait linked to its reproductive strategy, which is partially dependent on fire (Hauser, A. Scott. 2007). The plant is found in ecosystems with diverse fire regimes, experiencing fire-return intervals ranging from as short as 1 year to several hundred years (Hauser, A. Scott. 2007). The species responds to fire by establishing from seed, with seedlings often emerging abundantly in the first postfire year (Hauser, A. Scott. 2007).
Photo: Pat Breen, Oregon State University
Bigleaf Maple (Acer macrophyllum):
Bigleaf maple is not fire-resistant due to its relatively thin bark (Fryer, Janet L. 2011). In the immediate aftermath of a fire, the species experiences top-killing across various size classes, although mature trees with thick bark may survive moderate-severity fires (Fryer, Janet L. 2011). The plant's postfire regeneration strategy involves sprouting from a root crown, and it can act as both a colonizer on-site and, to some extent, off-site through seed dispersal (Fryer, Janet L. 2011). Bigleaf maple's ability to sprout from adventitious buds on the root crown enables it to recover after most fires (Fryer, Janet L. 2011). Fire generally favors bigleaf maple, postfire establishment occurred even after severe fires (Fryer, Janet L. 2011). The species plays a role in early postfire succession in Douglas-fir forests (Fryer, Janet L. 2011). Prescribed fires have been shown to favor bigleaf maple sprouting, although complete control of the species may be challenging (Fryer, Janet L. 2011).
Tobacco Brush (Ceanothus velutinus):
After a fire event, tobacco brush can regenerate from both seed and root crown sprouting, typically achieving postfire recovery within 2 to 5 years (Anderson, Michelle D. 2001). Fire often leads to a substantial increase in Tobacco brush density, particularly following severe burns, where seeds stored in the soil are stimulated to germinate (Anderson, Michelle D. 2001). The plant's height growth after fire is variable and influenced by the severity of the burn (Anderson, Michelle D. 2001). Fire management considerations underscore the importance of the season of burning, with low-severity spring burns favoring regrowth from root crowns, while severe summer and fall burns stimulate seed germination (Anderson, Michelle D. 2001). Slash disposal through broadcast burning after harvesting activities commonly results in Tobacco brush establishment, with burned sites exhibiting higher occurrence and density compared to unburned sites (Anderson, Michelle D. 2001).
Sugar Pine (Pinus lambertiana):
Sugar pine, characterized by its resistance to low- to moderate-severity fires through features like thick, fire-resistant bark and an open canopy inhibiting aerial fire spread, demonstrates a preference for bare mineral seedbeds in its early stages (Habeck, R. J. 1992). The species is considered an off-site colonizer, dispersing seeds through wind, animals, or water during the initial two postfire years (Habeck, R. J. 1992). As observed on the sites I visited, sugar pine will find it difficult to establish if a parent tree is too far away. Young sugar pines are susceptible to low- to high-severity fires, while mature trees can withstand most fires. Their vulnerability to postfire insect and disease attacks is generally low (Habeck, R. J. 1992). Research indicates that prescribed fires can effectively reduce fuel load and subsequent wildfire severity and suppression costs (Habeck, R. J. 1992). In response to low-severity fires, sugar pine enhances germination by seeding on exposed mineral soil, but high-severity fires during stressful periods can lead to mortality (Habeck, R. J. 1992).
Pacific Rhododendron (Rhododendron macrophyllum):
Pacific rhododendron, a disturbance-sensitive plant, experiences top-killing in response to fire across all severities, with severe fires posing a higher risk of plant mortality (Duchac, Leila. 2021). As observed the species demonstrates postfire adaptability by sprouting from the root crown, leading to rapid growth and the formation of dense thickets. It tends to exhibit higher cover on unburned or low- to moderate-severity burned sites compared to high-severity burned sites (Duchac, Leila. 2021). Pacific rhododendron's response to clearcutting and slash burning involves an initial sharp decline in cover, followed by a gradual increase, peaking around 20 years post-treatment (Duchac, Leila. 2021). Fuel characteristics vary, with the plant contributing to understory fuels and potentially acting as a ladder fuel (Duchac, Leila. 2021). The species occurs in forests with diverse historical fire regimes, and fire management considerations include understanding its role in altered forests, particularly in timber plantations, where control measures such as broadcast burning may offer initial effectiveness but not long-term control (Duchac, Leila. 2021). The plant's persistence in low-nutrient soils influences its response to fire and its ability to thrive in specific forest types (Duchac, Leila. 2021).
Photo: Oregon Sate University
Buckbrush (Ceanothus cuneatus):
Buckbrush demonstrates fire adaptations with its high flammability, considered beneficial for seed germination and establishment after fire (League, Kevin R. 2005). Immediate fire effects result in the death of buckbrush, particularly due to its flammable mature canopy during the dry season (League, Kevin R. 2005). Based on my experience with this brush species, it can cause fire to burn with great intensity. This can lead to high-severity fires. Postfire, buckbrush exhibits successful establishment, primarily in the spring following burning (League, Kevin R. 2005). However, factors such as soil moisture, competition, and herbaceous interference influence seedling survival rates (League, Kevin R. 2005). Frequent fires may reduce buckbrush stands(League, Kevin R. 2005).
The Potential Future of the Rogue-Siskiyou National Forest
Climate:
Engaging in discussions about climate is crucial as we are aware it shapes our environment, ecosystems, and societies. In the Pacific Northwest, significant changes driven by shifting climate patterns are evident, highlighted in studies led by Jessica E. Halofsky in 2022. Her research focuses on the recent increase in wildfires, emphasizing the impact on resource managers, fire scientists, and the public, revealing a strong link between notable fires and prevailing warm, dry conditions.
Projections, based on historical data and modeling, anticipate more instances of warm, dry conditions in areas like the Rogue-Siskiyou National Forest, potentially leading to extended fire seasons and increased frequency (Jessica E. Halofsky et al. 2022). Within a warming climate, her work identifies fire interactions with disturbances like drought and insect outbreaks as primary drivers of ecosystem transformation.
In a parallel exploration led by Michael C. Wimberly, the climate trajectory of the Pacific Northwest is a central focus. Projections from the IPCC Fourth Assessment Report (Mote and Salathe. 2010), indicate a noticeable temperature increase, particularly in summer. Wimberly's and Salathe's influential contributions enhance our understanding of the region's climatic journey, though uncertainties persist regarding precipitation shifts (Mote and Salathe. 2010).
Wimberly's and Salathe's analysis of historical fire scar data reveals a historical link between widespread wildfires and dry conditions, anticipating expanded burned areas, especially in forested ecosystems like the Western Cascades and Blue Mountains. Their work underscores the vulnerability of fire parameters to climate change, signifying potential implications for size and severity due to diminished fuel moisture, impacting the distribution of major tree species and reshaping the Pacific Northwest's forests.
What future plant communities' Of the Rouge- Siskiyou may look like:
As the climate undergoes changes and fire regimes evolve, I predict plant communities are destined for transformation. Hobbs et al.'s meticulous 1992 study delves into the uncertain prognosis of forest recovery post high-severity fires, revealing a historical context marked by concerning regeneration failures of conifers after fires and logging activities. This historical evidence raises substantial concerns about the enduring sustainability of conifer forests in the region.
In 1959, Hayes, G.L. discusses the limited understanding of the environmental requirements of brush species and the crucial role of fire in creating and maintaining brush fields. The article suggests variability in the suitability of brush-covered sites for forests, emphasizing the need to prioritize reclamation efforts on the best forest sites. Concerns are raised about extensive brush fields that generate no economic returns and may impact watershed functions (Hayes, G.L. 1955) . As observed on the sites I surveyed, brush species are thriving in high-severity burn areas, while conifer species like Douglas-fir and sugar pine are sparse. The small Douglas-fir and sugar pine growing in these areas are seeds from trees that survived the fire, receiving protection from the brush but also facing competition. The ongoing process raises questions about the future, especially with the continuation of hotter and drier climates and more intense fires (Jessica E. Halofsky et al. 2022). While hardwood species and shrubs have proven their ability to survive, the fate of conifers remains uncertain.
Brown and Smith's 2000 study reveals substantial regrowth from observed species examined after fires, raising concerns about their potential dominance post-fire. These species, including hardwoods like tanoak and various bush species of Ceanothus, as well as madrone, were observed, mirroring the species observed on the sites I investigated.
J.P.A. Shatford's et al. 2007 ecosystem recovery study reveals the presence of shrubs and resprouting hardwood trees, indicating a positive association between conifer abundance and the cover of hardwoods and shrubs. However, a different trend is observed within the white fir series, where conifer seedling abundance decreases with hardwood/shrub cover (J.P.A. Shatford et al. 2007). Despite this, seedling establishment remained notably high, suggesting limited competition from broad-leaved species (J.P.A. Shatford et al. 2007). The study notes conifer seedlings are frequently overtopped by shrubs and hardwoods.
However, when contemplating the future and considering the predicted increase and intensification of fires (Jessica E. Halofsky et al. 2022), I question whether conifers, such as Douglas-fir, can continue to compete. The anticipated changes in soil conditions further add to this uncertainty (D. W, SMITH. 1969). While observations by J.P.A Shatford are positive in the current context, my concern is about the sustainability of conifers in a future where fires are expected to increase and become more severe (Jessica E. Halofsky et al. 2022). In one study it took around 20 years for conifers to gradually grow to the point of overtopping post-fire (Tepley et al., 2017). Although predicting the future is challenging, based on the literature I have reviewed, it appears that conifers may face greater challenges in reproducing and competing in the future, especially with the climate change that will continue to take place.
Jessica E. Halofsky's exploration emphasizes the profound impact of changing climate and fire dynamics on forest regeneration processes, potentially leading to a decline in the density of resprouting species and local elimination of those dependent on seed reproduction. Climate change's influence on fire frequency and severity could significantly affect post-fire regeneration, highlighting the intricate relationship between climate change, fire dynamics, and the future trajectory of forest ecosystems (Halofsky et al. 2020).
The impact of wildfires, particularly on Federal lands in dry forest zones, has notably escalated (Michael C. Wimberly et al. 2014). Examining the aftermath of wildfires in the dry forests of the eastern Washington Cascades and the Klamath region in southeastern Oregon, Michael C. Wimberly's et al. 2014 study reveals a surge in the loss of large-diameter forests after 1992, surpassing levels observed in the preceding two decades. This underscores the increasing vulnerability of these ecosystems to wildfires. Looking ahead, the prognosis is concerning, with the expected intensification of older forest loss due to more frequent wildfires (Michael C. Wimberly et al. 2014). This heightened rate of loss may outstrip the comparatively slow processes of tree growth and forest succession, emphasizing the need for proactive measures to address the growing challenges posed by escalating wildfire impacts on these vital forest ecosystems (Michael C. Wimberly et al. 2014).
Exploring Management Strategies:
This project within the Rogue-Siskiyou National Forest has meticulously documented a diverse range of species, some thriving within distinct post-fire environmental niches. We recorded numerous hardwood and brush species alongside Douglas fir and sugar pine. However, it raises the question: what types of conifer species, besides Douglas-fir and sugar pine, were observed outside of areas recently affected by fires? In higher elevations, true firs (Abies spp.) dominate the landscape. Ponderosa pine (Pinus ponderosa) and Jeffrey pine (Pinus jeffreyi) were also observed alsongide incense cedar (Calocedrus decurrens). Additionally, other hardwood species were documented. Among the common and notable species we observed are black oak (Quercus kelloggii), white oak (Quercus garryana), and canyon live oak (Quercus chrysolepis).
The Rogue-Siskiyou exhibits a diverse array of conifer species that we must work to preserve. As observed species like ponderosa pine, with its thick bark, have demonstrated greater resilience to survive fires. In contrast, other species with thinner bark struggle to cope with fire, true firs tend to be these species. Conifers play a crucial role in the overall ecology of the Rogue-Siskiyou National Forest, and efforts to preserve and protect these species are paramount for the forest's health and resilience. This prompts the question: what actions can we take to maintain robust timber stands in our forests including conifers, rather than just stands of brush and hardwood species?
I feel that, at this time, it's important to address the issue of climate once more. This topic is broad and unfortunately so vast that I can't fully address all the issues surrounding it or how to fix it. I want to briefly state, though, that mitigating climate change is crucial to managing our forests. Managing the climate is essential for reducing wildfires due to its direct impact on environmental conditions that influence fire behavior (Jessica E. Halofsky et al. 2022). Climate management aims to mitigate factors contributing to the increasing frequency and severity of wildfires. Elevated temperatures, prolonged droughts, and changes in precipitation patterns associated with climate change create conditions conducive to wildfire ignition and spread (Jessica E. Halofsky et al. 2022). By addressing climate-related factors, such as implementing sustainable land management practices and reducing greenhouse gas emissions, we can work to mitigate the risk of wildfires. Proactive climate management is essential for fostering resilience in ecosystems, protecting communities, and preserving biodiversity, ultimately contributing to the overall safety and health of our environments.
But what can forest managers currently do to help maintain robust timber stands? In 2009, Daniel C. Donato et al. conducted a study in the Klamath-Siskiyou Mountains on the Biscuit Fire. His findings revealed that the fire resulted in complex burn patterns and dispersed seed sources from conifers. Notably, most severely burned areas were in proximity to living trees, with 46%-70% within 200 meters and 71%-90% within 400 meters (Daniel C. Donato et al. 2009). The study observed high plant regeneration across distances ranging from 62 to 552 meters, with a gradual decline. Median densities remained above 1,000 seedlings per hectare up to 400 meters, dropping below 300 seedlings per hectare beyond that distance (Daniel C. Donato et al. 2009).
The importance of this lies in the reliance of conifers, such as Douglas-fir, on nearby seed sources for regeneration. The wildfire's impact on burned areas and seed sources varied, revealing a threshold effect in plant regeneration at 400 meters from surviving trees (Daniel C. Donato et al. 2009). White fir (Abies concolor), among other conifers studied, was rarely found beyond 220 meters, while sugar pine and knobcone (Pinus attenuatapine) showed scattered distribution without clear distance patterns (Daniel C. Donato et al. 2009).
The study emphasized that areas distant from seed sources, such as the center of the Biscuit Fire, underwent limited new growth and were dominated by regrown hardwoods and shrubs. Based on my own understanding and reading of Daniel C. Donato's et al. study, it is important that planting occurs after a high-severity burn. Conifers in the area heavily rely on seed sources from other conifers. If the burn area is extensive, it may require assistance from forest managers through replanting efforts to ensure the continued presence of conifers.
Another common practice after a fire is salvage logging. Salvage logging, also known as timber salvage or post-fire logging, involves harvesting or removing trees damaged or killed by natural disturbances like wildfires, insect infestations, windstorms, or disease outbreaks. The primary goal is to recover economic value from the timber before it deteriorates or loses commercial viability due to the natural disturbance. But is this practice positive post-fire besides for economic purposes? In 2022, Sarah Sterner et al. found that the lower coverage of Ceanothus brush types in areas restored by the U.S. Forest Service (USFS) significantly decreased in areas with more tree salvage activity (Knapp & Ritchie, 2016). These brush species were affected by the mechanical disturbances from the restoration efforts (Knapp & Ritchie, 2016).
In a 2013 study in Lassen National Forest, it was discovered that after intense wildfires, salvaging timber and replanting in areas resulted in a rich mix of new conifer growth (Collins & Roller, 2013). Sarah Sterner et al. noted that USFS Restored sites showed higher abundance and diversity of saplings compared to other management types. Out of the areas managed by the U.S. Forest Service (USFS), 87.5% of the restored plots had young trees growing, compared to 21.4% of USFS sites without restoration efforts (Sarah Sterner et al. 2022). So, what is the point of this information that I am giving you? Sarah's et al. 2022 study showed that salvage logging and replanting of conifers contributed to more conifer regeneration than if they were left alone.
There is a concern with salvage logging that I'd like to point out based on other studies. Salvage logging has been linked to negative effects because it can change the structure and composition of forest stands (Lindenmeyer, 2006). Studies by Thompson et al. in 2007 also showed that areas undergoing salvage logging and subsequent planting experienced more severe burns fifteen years later compared to unmanaged areas. The disturbance from mechanical harvesting had a negative impact on conifer regeneration shortly after salvage logging (Thompson et al. 2007).
The key takeaway is that replanting with conifers after harvesting and post-fire planting activities are expected to increase conifer abundance, potentially balancing each other out (Sexton, 1998).
In Maria Jose Lopez's et al. 2019 study, the examination focused on sites that had undergone high-severity fires, with specific treatments applied in designated areas 20 years prior. These treatments included site preparation, the planting of Douglas-fir and ponderosa pine, and shrub removal to encourage conifer regeneration. However, the study results indicated that these management treatments did not significantly impact the cover among physiognomic groups, including conifers, hardwoods, and shrubs. Notably, shrubs consistently remained the dominant cover type in the study area (Maria J. Lopez Ortiz et al.2019)
Despite the limited impact on overall vegetation cover, one notable finding emerged. In managed sites, the presence of taller dominant conifers compared to unmanaged sites suggested that post-fire management measures, such as site preparation, planting, and shrub removal, may be effective in supporting the survival of conifers during subsequent fires (Maria J. Lopez Ortiz et al. 2019).
In a thesis project conducted by Maria Jose Lopez Ortiz in 2007, it was observed that despite considerable efforts to restore conifer forests in the Klamath-Siskiyou region—such as planting, salvage logging, fuel treatment, and release cuts—the interventions seemed to have little impact. Lopez's study's have shown that forests are often very resilient, and conifers will continue to replant. This is reassuring, especially considering the ongoing occurrence of large fires. However, the concern arises in situations like the Biscuit Fire mentioned earlier. In these cases, the environment may need a jumpstart through implementing replanting measures. Human actions, like planting conifers, play a key role in preserving species that store seeds—especially vital as our climate warms up. Research indicates that these species might struggle to recover in the face of more frequent and severe fires. This is why it is important for conifers to have a nearby seed source.
If I were a forest manager, you might wonder what strategies I would employ. After considering scholarly articles mentioned earlier and drawing from my own observations during wildland firefighting, site restoration, and timber work, I've compiled a quick summary of some strategies I would personally use after a high-severity burn.
Replanting: First and foremost, I believe that replanting is vital. However, it's important to note that this doesn't have to be done in all areas. As studies discussed earlier have shown, the forest does a wonderful job of regenerating itself. That being said, planting trees is a crucial step in restoring the ecological balance. While I cannot predict the future, based on current climate projections, things are expected to continue becoming hotter and drier. Fires may continue to intensify, as they have been doing. With all that being said, our conifer friends will need a bit of extra help, and replanting is a way to provide that support.
Photo: Oregon Forest Resources Institute
Salvage Logging: Salvage logging has been shown to be helpful and, at the same time, a bit scary for forest managers. It has been shown to help conifers establish, but the disturbance caused to the forest from it indicates decisions need to be made carefully. I believe salvage logging can be useful, especially in recouping costs of forest restoration. However, its use needs more research to discern the full environmental impacts.
Photo: Rich Pedroncelli / Associated Press
Site Preparation: Preparation is key; we want to do everything we can to give conifers a fighting chance before planting. In a recent conversation with my husband, Beau Lee, who holds a management position as a wildland firefighter for the Bureau of Land Management (BLM), concerning site preparation for planting, he highlighted the significance of specific steps in the process. Site preparation is crucial for various reasons, one of which involves the implementation of erosion control measures. These measures are designed to prevent soil erosion and sedimentation, employing techniques such as the use of erosion control blankets, wattles, and mulching. Furthermore, proper site preparation plays a pivotal role in fostering the growth of native species while discouraging the proliferation of non-native ones. This is essential for maintaining the ecological balance of the area and supporting biodiversity. By creating an environment conducive to native species, we contribute to the overall health and resilience of the ecosystem. During this phase, firefighters actively engage in preparations for future fire events by maintaining and creating future fuel breaks. They focus on stabilizing the soil through reseeding or replanting native vegetation, a practice aimed at promoting ecosystem recovery. Additionally, the application of mulch serves as a crucial step to retain moisture, control erosion, and provide protection for seeds and seedlings, contributing to the overall success of the replanting efforts. Effective water management emerges as another critical aspect of site preparation. This involves strategies such as the installation of water bars, culverts, and shaping the landscape to direct water flow. By managing water effectively, the risk of flooding and soil erosion is minimized, ensuring the long-term sustainability of the planted vegetation and the overall health of the ecosystem.
Photo: Pixabay
Fuel Management Prescribed Fire/ Maintenance Burning: Fuel management before a fire, and then post fire is of the utmost importance to give our conifers a fighting chance. Michael C. Wimberly's et al. research in 2014 found that treatments like thinning the canopy and using prescribed burns for surface fuels can make a significant difference in reducing the severity of wildfires in treated areas (Michael C. Wimberly et al. 2014). It's interesting to note that just conducting timber harvests, a common forest management practice, might not necessarily enhance protection to our forests. In fact, if the leftover materials from harvesting are not treated with prescribed fire, it could even increase the risk of fires (Raymond and Peterson, 2005). When considering fire risk, it's crucial to account for different types of fuels, such as those on the ground, on the surface (like litter, grasses, and shrubs), and up in the trees. Among these, surface fuels, often untouched by timber harvest, can be especially risky in many forests (Stephens et al. 2012). The study highlights that using prescribed fire, especially when applied to surface fuels by Forest Service managers, is a powerful way to lower the chances of intense fires compared to relying solely on mechanical treatments (Stephens et al. 2012). After discussing the matter with my husband once again, particularly regarding his deep involvement in the subject, he highlighted another crucial aspect of this equation. Maintenance burning is also highly significant; it's not sufficient to burn only once and consider the task complete. Once shrubs start asserting dominance, it becomes essential to revisit and conduct additional burns. The objective is to consistently reduce fuel loading in the forest.
Photo: National Park Service
Invasive Species Management: I have observed many times that after fires, invasive species can start to creep in. Controlling invasive plant species that can hinder the natural recovery of native vegetation is essential. These species can outcompete native plants and disrupt the ecological balance. Vigilant management and preventive measures are crucial to curbing the spread of invasives and promoting the restoration of the natural ecosystem.
Photo: Kirsten Noel
Monitoring and Research: Regular monitoring and research activities play a crucial role in assessing the effectiveness of restoration efforts and providing insights for adaptive management. This ongoing evaluation helps refine strategies and adapt to changing conditions. By staying informed through systematic monitoring and research, forest managers can make informed decisions, enhance the success of restoration initiatives, and contribute to the long-term health of the ecosystem.
The following video provides a quick summary of the key points I hope you can take away from this project. It's important because it offers a concise overview of the essential aspects discussed, allowing for a better understanding and retention of the information.