Maxwell Creek Watershed Project Field Files Part 4: Managing fire in a climatically uncertain future

The removal of traditional burning, suppression of natural fire, and frequent droughts have increased the risk of severe fire in Coastal Douglas-fir forests. The Maxwell Creek Watershed Project is investigating treatment strategies to reduce that risk.

As previous installments of the Field Files series have established, since settler arrival in the Coastal Douglas-fir (CDF) zone, forests have been extensively harvested. The consequence of this widespread, industrial-scale logging is predominantly second growth forests that are not only lacking in biodiversity and natural complexity, but also at a higher risk of burning in catastrophic fires. This is of particular concern to Gulf Islanders, most of whom live in the forest/rural interface.  

The aim of the Maxwell Creek Watershed Project (MCWP) is to design and test nature-based solutions that reduce the risk of fire and other climatically induced disasters (e.g. flooding, severe windthrow events) in the CDF while also increasing ecological integrity and climate resilience. The Maxwell Creek watershed (“the watershed”) was chosen as the site for this project due to its classic post-harvest structure: approximately 50-60 years into its recovery, densely spaced, and evenly aged. It serves as an accurate representation of CDF forests across the Gulf Islands, and thus will provide an easily replicable template for other restoration practitioners in the region. By no means is this the only stand type found on the Gulf Islands, but it does occur very frequently.

Young, dense forest on a foggy day.
Dense, even-aged forest within the Maxwell Creek watershed. Photo by Pierre Mineau.

Robert Seaton, veteran forest ecologist with more than 30 years of experience implementing forest restoration projects, was asked to join the team to assess fire risk throughout the watershed, particularly the areas that are controlled by project partners, the North Salt Spring Waterworks District (NSSWD). Robert’s role is to determine whether there is an exaggerated fire risk on this landscape and if so, identify potential treatment options to reduce that risk. He was interviewed to inform this article.

Assessing fire risk: A practice in ecological restoration

Assessing fire risk and understanding how fire might impact the landscape is not just about fire, it requires consideration of all ecological elements that together form the ecosystem. To increase fire resistance, a higher level of biodiversity and ecological integrity must be established and maintained. Some of the forests in the watershed have gone through a self thinning process which has resulted in a lot of small woody debris accumulating on the forest floor in some places. Other areas have very high crown closure. Neither scenario  is representative of a healthy forest. As an initial treatment, the MCWP team will focus on the latter and moderately reduce canopy closure by thinning out dense stands. This will be a first step toward establishing the “clump-and-gap” structure typical in mature and old growth forests, where there is enough light, nutrient, and water availability to enhance understory growth and establish a more heterogeneous forest structure. In other words, this will facilitate a more balanced mix of age and size classes in contrast to the dense stands of uniform size, age, and species currently characteristic of the watershed. 

Young, thin forest on a sunny day.
A forest stand post thinning treatment. Photo by Tal Engel.

As is the case of all things in nature, this process will take time. Attempting to achieve this vision all at once would mean taking out too many trees, leaving those that remain standing at significant risk from windthrow. The initial treatment of thinning a few trees is just the first step in a longer-term density reduction process that will allow the forest time to grow and become more wind firm prior to the next thinning  treatment. 

Some thinning was done in the watershed about 20 years ago with timber harvest rather than the ecological recovery in mind. As such, it did not result in significant understory regeneration, but it did provide the opportunity for a second age cohort of trees to establish. This demonstrates that just thinning trees is not enough to facilitate ecosystem recovery. Typically, ecological recovery takes significant time, in the order of hundreds of years. In the case of the Maxwell Creek watershed, it will take significant work to accelerate the process. Work in forest stands with a logging history, like those found in the Maxwell Creek watershed, is always very complex. In many ways, logging sets forests on a different ecological trajectory. To facilitate their recovery means trying to bring them back to a trajectory resembling the one they would have been on if they had never been harvested in the first place.

Person walking through an old growth forest on a sunny day.
A mature forest, demonstrative of the natural clump-and-gap structure described by Robert Seaton. Photo by Alex Harris. 

In addition to thinning, a future step may be a widespread understory replanting effort to reintroduce species diversity to the forest floor, which has largely been eliminated due to lack of light and high competition caused by the current level of tree density. Many understory plants native to the CDF region are fire adapted, they tend to have water-like sap and moist leaves with low flammability index values. This does not necessarily mean that these plants will not be damaged or even killed by fire, but rather that they will not readily ignite and do not contribute to a fire’s intensity. According to an interview with Amy Jo Detweiler, a horticulturist with Oregon State University, these plants can essentially “create a living wall that reduces and blocks intense heat.” Restoring biodiversity of plants would not only enhance habitat values and ecological integrity, but also increase fire resilience.  

Fire resistant shrubs native to the CDF zone

Salal berries that aren't ripe.
Photo 4: Salal (Gaultheria shallon). By Alex Harris.
Red flowers on a green vine with sun on it.
Photo 5: Red -flowering currant (Ribes sanguineum). Photo Alex Harris.
Purple berries (also known as oregon grapes) on a green plant.
Low (or dull) Oregon grape (Mahonia nervosa). Photo by Alex Harris.
Tree with buds on it.
Red osier dogwood (Cornus sericea). Photo by Alex Harris.

However, reestablishing the complexity of a mature forest is not only a long, but also an expensive process. The level of restoration treatment possible will be dependent on the amount of funding available. Thus to start, replanting in the watershed will occur on a smaller scale with a few trial sites. A few exclusion zones will also be established to measure the impact of deer browse on regeneration of the understory post-treatment. The hyperabundant deer population present on Salt Spring – as on most Southern Gulf Islands – has clearly been impactful to the understory in the project area and beyond, though Robert suspects that the dense forest structure may be more influential to the state of the understory. 

Going forward, significant ongoing monitoring will be needed to determine the efficacy of treatments. If outcomes from this first phase are positive, it is likely that further funding will be secured and additional phases will be possible. Future treatments would include increased reduction of canopy closure and additional planting to push the forest closer to that clump-and-gap structure.

Personalizing the template

In the early 2000’s, Ken Millard, decades-long volunteer with the Galiano Conservancy Association (GCA), developed a pulley system to simulate windthrow in Douglas-fir plantation forests. The idea was to thin dense stands using non-intrusive methods (i.e. no roads, vehicles, or power tools needed). Downed trees were then either left to decompose in place or redistributed where needed in the forest to enrich soils and create habitat. This is just one example of methods used in this region to restore forests that have been heavily impacted by human activity. 

Despite one of the anticipated outcomes of the MCWP being the production of a replicable template, every project is going to be a little different. For example, though the MCWP builds on some of the lessons learned from projects like the GCA’s, the Project’s restrictive budget and limited timeline mean that the repeated installation of the handheld pulley system throughout the entire watershed may not be a feasible method of tree removal. Further, the Project’s strong fire focus means much consideration must be given to the distribution of coarse woody debris on the forest floor. Though such debris does introduce nutrients to the landscape, it can also create a short-term burst of fine fuels. To manage fire risk, removing some woody debris will be necessary. As such, in planning treatments it will be essential to identify sites where felled trees can be left behind and where they cannot. 

Many of these decisions will have to be made in situ based on observed conditions at the time of treatment. Though the Project team has done extensive spatial analysis (see Field Files installment 3) and ground truthing, the decision about where to leave coarse woody debris is dependent on the current condition of the understory. Generally, coarse woody debris is not very flammable; it is like trying to light a log with a match–it doesn’t burn well. But, if there are concentrated piles of fine fuels nearby, heat can be trapped and smolder, in which case the large woody debris can feed the flames, causing a much larger problem. 

Flame emoji.

Treatment Case Study: Managing fine fuels in-situ

The MCWP team is preparing field trials, testing methods for managing fine fuels using ‘berm-like’ constructions which serve the additional role of providing wildlife habitat and structural complexity that is currently lacking. The goal is to develop in-situ methods that can be readily used, where needed, to increase soil moisture, soil organic content, and reduce nutrient leaching while also increasing fire resilience. 

A berm-like structure as a potential model for fine fuel management. Photo by Tal Engel.
Salal regeneration shows that the piles hold moisture and aid in diversifying the understory. Photo by Tal Engel.

If coarse woody debris removal is deemed necessary, it is likely that additional community support will be needed. To remove wood from the site using any kind of vehicle or heavy machinery would result in soil compaction and/or significant damage to the understory. However, to remove it by hand would be incredibly labour intensive and beyond the capacity of the small project team. Inviting a community of volunteers to help could be the solution to this problem. While it would not be economically viable to produce and sell firewood to support this project, if a group of individuals were willing to help they could keep the wood for their own use or resell it for as part of a fundraiser or something similar. 

Challenges in translating the Project to practice

The high private ‘ownership’ of land on Salt Spring and other Gulf Islands presents many challenges for both protecting communities from fire and forest stewardship. The Project was made possible by public funding, allowing Transition Salt Spring to assemble a community of practice from across the Gulf Islands (and beyond) to combine their expertise to improve understanding of the historic and current ecological conditions within the watershed. It required the buy-in of NSSWD and a community of additional land managers and owners. 

All of this effort was necessary to do the predictive and local scale fire risk work in this one area of the island.  Once the project funding ends, the community will again be in a situation with minimal resources to actually implement treatments, monitor their impacts, and share learnings with other communities. According to  Fire Ecologist Kira Hoffman, these sorts of individual attempts to control fire risk are largely ineffective in her experience in the interior forests of BC. They must be undertaken on a wider scale. 

Ultimately, the MCWP is a small trial, a demonstration. It is an important project and very much needed, but to start thinking about forests in a way that maximizes biodiversity, a much larger effort is needed with a lot more financial support. On the Gulf Islands a majority (>80%) is privately owned. Some of these landowners might be interested and willing to apply treatments on their own properties. This sort of community buy-in will also be necessary to ensure the efficacy of this work. 

Project outcomes

There are two expected outcomes from this project: the tangible (i.e. on-the-ground methods) and the intangible (i.e. changing thinking about ecological management and fire risk, particularly in the industrial sector). 

What we are implementing within the Maxwell Creek watershed, which as noted above is an ecosystem similar to many seen across the Gulf Islands, will reduce fire risk and accelerate a more ecologically diverse structure. This sort of management regime is something land managers working at all scales need to be thinking about, particularly as the impacts of climate change become more evident on the landscape. While this is true for restoration projects, like the MCWP, it also needs to apply to commercial endeavors. In Washington State, thinning treatments are being undertaken with the additional goal of removing viable timber. Though this is a more ecologically viable way of pursuing timber harvest than has been done historically, the machinery used has an impact and there is still not enough attention paid to restoring ecosystem functions. So some goals are met, but some are not. 

We need to be clear about what our goals are – not just in the CDF but everywhere that forestry exists as an industry. This problem exists all over BC. Government and industry have long claimed that the forestry sector manages for multiple values, but basic management methods and rules on the ground are very much oriented towards timber production. Ecological functionality has not been incorporated into management decisions to the degree that it needs to be. We need to answer the question: How does timber production continue while also maintaining stand structure, ecological functionality, wildlife habitat, and cultural forest use? Implementing more restorative practices into the commercial sector would dramatically expand opportunities for enhancing ecological integrity and reducing vulnerabilities to climate change, particularly because projects in this sector tend to have larger operating budgets than those being pursued by charitable and/or not-for-profit organizations.

One way to understand this is thinking of the MCWP as an “after-the-fact” attempt at restoring a heavily altered landscape. However, in the future  we need to employ “before-the-fact” approaches, managing landscapes and industries in such a way as to avoid causing problems we are seeing now, like increased fire risk, flooding, and biodiversity loss. 

About Robert Seaton

Robert Seaton is a forest carbon and ecological restoration expert. Robert is an expert forestry analyst, focusing on natural system valuation and the economics of sustainability, including through the integration of timber, grasslands, soil and other natural systems with carbon values. Robert is the lead author of a range of carbon sequestration protocols, methodologies and project design documents. He has developed many protocols including a REDD methodology under the Voluntary Carbon Standards for the World Bank BioCarbon Fund 2010, as well as a risk mitigation carbon asset structure for REDD carbon assets in British Columbia, Canada, in 2010. In addition, Robert has worked on many international forest carbon projects including projects in Zambia, Indonesia, Tanzania and Honduras.

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