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Colorado’s Forests Struggle Under Extreme Heat, Drought, and Pests

Rising temperatures, persistent drought, and invasive insects are rapidly reshaping Colorado’s mountain forests, threatening their future.

By Sneha Tete, Integrated MA, Certified Relationship Coach

Created on Sep 27, 2025

Rising temperatures, persistent drought, and invasive insects are rapidly reshaping Colorado’s mountain forests, threatening their future.

Colorado’s Forests Face a Growing Crisis

Colorado’s mountain forests, celebrated for their beauty and biodiversity, are increasingly threatened by a convergence of record-breaking heat waves, persistent drought, and an onslaught of destructive pests. Together, these pressures are causing widespread tree mortality, fundamentally altering forest ecosystems and fueling larger, more intense wildfires. Scientists, land managers, and local communities are sounding the alarm: the forests as we know them may be changing forever.

The Impact of Extreme Heat and Drought on Forest Health

Over the last several decades, Colorado has experienced a clear trend toward a warmer and drier climate. According to the Colorado State Forest Service, the state has seen four of the five warmest years in its recorded history since 2000. Statewide average temperatures have risen 2.3°F from 1980 to 2022, resulting in increasingly frequent and severe drought conditions. Trees—especially in high-elevation ecosystems—evolved to survive cool, moist winters and relatively mild summers, but the mounting heat is pushing them beyond their natural tolerance.

Water Stress: Prolonged drought leaves trees without the water they need to photosynthesize and produce resin, their primary line of defense against insects and diseases.
Vulnerability to Pests: Stressed and weakened trees are prime targets for bark beetles and other pests, leading to cascading die-offs.
Increased Fuel Loads: Dead and dying trees pile up on the forest floor and within the canopy, providing extensive fuel for wildfires.

Forest Pests: Beetles and Budworms on the Rise

Bark beetles, particularly the mountain pine beetle and spruce beetle, have decimated millions of acres across the Rockies. These insects, normally kept in check by cold winters and healthy tree defenses, now thrive in warmer, drier conditions. Other pests, like the western spruce budworm, have expanded their range and impact. The Colorado State Forest Service’s annual aerial surveys document a relentless spread of infestations, especially after dry years.

Cycle of Outbreaks: Reduced precipitation one year sets up explosive beetle populations the next, as trees can’t fend off attackers.
Wide Area Damage: In 2023 alone, Mesa County saw over 7,500 acres affected by the western spruce budworm.
Compounding Effects: Death from pests not only weakens the forests but also increases the risk and severity of wildfires.

Wildfires: Bigger, Hotter, and More Unpredictable

Colorado’s wildfires have escalated in both size and intensity in recent years. Of the 20 largest wildfires in state history, all have occurred since 2001, with many since 2012 and nine since 2018. Hotter temperatures, thicker forests strangled by pests, and prolonged drought create the perfect storm for explosive fires.

Changing Fire Behavior: Firefighters report seeing fire behavior “like we haven’t seen before,” including fires burning hotter and moving faster.
More Fuel, More Fire: Dense growth and accumulated deadwood serve as potent fuel for fires that can quickly escape control.
Wildland-Urban Interface Risk: As more people move into forests and mountain communities, the risks to life and property grow dramatically.

Breaking the Natural Cycle: Fire-Adapted Yet Vulnerable Ecosystems

It’s important to recognize that Colorado’s forests have evolved alongside fire. In a healthy system, periodic low-intensity fires play a vital role in clearing undergrowth and maintaining diverse, resilient plant and animal communities. But climate change has driven these fire cycles—and the ecosystems themselves—beyond historic norms.

Runaway Fire Seasons: Fire-adapted landscapes like sagebrush and pinyon-juniper woodlands are now experiencing fires that burn hotter and longer than ever before.
Breakdown of Resilience: When fires become too frequent or intense, they destroy seed banks and root systems, preventing the forest from regenerating naturally.
Altered Ecosystems: Scientists worry that high-elevation forests dying off from extreme events may not return as forests at all, but instead could shift to grassland or shrubland.

Environmental Impacts: Carbon Emissions and Climate Feedback Loops

Forest die-off doesn’t only affect local landscapes and economies; it reverberates globally through the carbon cycle. Healthy forests absorb massive quantities of carbon dioxide, helping to blunt climate change. But as more trees die—from either pests, drought, or fire—they release instead of capture carbon, potentially flipping Colorado’s forests from a carbon sink to a carbon source.

Net Carbon Source: Recent studies confirm that, due to widespread mortality, Colorado’s forests now emit more carbon than they absorb.
Wildfire Emissions: Massive wildfires further accelerate the release of greenhouse gases, exacerbating climate change.
Feedback Loops: The result is a self-reinforcing cycle: hotter, drier conditions kill trees, which fuels fires and emissions, making the climate even less hospitable for future forests.

Key Stressor	Direct Effects on Forests
Extreme Heat & Drought	Tree water stress, reduced growth, diminished natural defenses, increased mortality
Insect Outbreaks	Widespread die-off, increased susceptibility to fire and further pest invasions
Frequent/Severe Wildfires	Destruction of vegetation, changes in soil composition, loss of wildlife habitat, increased carbon emissions

Lessons from the Landscape: What’s at Stake?

The widespread transformation of Colorado’s forests affects much more than trees. Water resources, recreation-based economies, cultural identity, and biodiversity all depend on healthy forests. As these systems tip toward collapse, their capacity to serve as wildlife habitat, purify water, stabilize soils, and provide recreation and resources diminishes sharply.

Water Security: Forested watersheds are vital for filtering and storing much of the state’s water; forest stress and death threaten water quality and supply for millions.
Economies in Peril: Tourism, recreation, and timber businesses all rely on functioning forests for livelihoods and local revenue.
Loss of Biodiversity: As key tree species die, entire web-of-life relationships unravel—affecting plants, insects, birds, and mammals.
Unique Colorado Landscapes: The signature alpine and subalpine vistas that define the state could transform dramatically within a generation.

Community Impacts: Safety, Infrastructure, and Lives at Risk

As Colorado’s population has grown, people are increasingly living in the wildland-urban interface—the zone where mountain forests meet neighborhoods and towns. This increases the risks posed by wildfires, dead trees, and habitat shifts:

Higher Fire Risk: More homes at the forest edge means greater vulnerability to fast-moving wildfires.
Hazards on Trails and Roads: Dead trees and falling branches threaten public safety, requiring expensive mitigation and clean-up efforts.
Evacuations and Property Loss: Each fire season brings the threat of evacuations, lost homes, and rising insurance costs.

What Can Be Done? Calls to Action and Future Prospects

Among the urgent recommendations from forest scientists and land managers:

Active Forest Management: Employ prescribed burns, thinning, and pest monitoring to reduce fuel loads and strengthen resilience.
Integrate Climate Adaptation: Prepare for shifting species compositions, and consider facilitating migration for tree species more likely to survive future conditions.
Support Community Preparedness: Bolster emergency response, raise public awareness, and incentivize fire-resistant housing and landscaping practices.
Reduce Emissions Statewide: While forests play a crucial role in carbon storage, climate experts caution that they cannot singlehandedly offset human emissions. Aggressive efforts to reduce greenhouse gases are essential to prevent even greater damage.

As Matt McCombs, Colorado State Forester, summed up: “Our forests can’t catch a break as our climate becomes warmer and drier… The good news is we know what to do to build more resilient forests and communities, but urgent, coordinated action is needed now.”

Frequently Asked Questions (FAQ)

Why are so many trees dying in Colorado’s forests?

Tree mortality is primarily driven by the combined effects of persistent drought, rising temperatures, and outbreaks of pests such as bark beetles and budworms. These stressors reduce trees’ natural defenses, making them more susceptible to disease and insect attack, ultimately leading to widespread death.

How are wildfires changing in Colorado?

Wildfires have grown larger and more intense in the past two decades, fueled by abundant deadwood from pest outbreaks, dense forests, and hotter, drier weather. Firefighters report unprecedented fire behavior and rapid fire expansion due to shifting weather patterns and increased fuel loads.

Are Colorado’s forests still absorbing carbon from the atmosphere?

No. For the past several years, dying trees have caused the forests to emit more carbon than they absorb. This is due to massive mortality from pests, drought, and fires, which has shifted forests from being carbon sinks to net carbon sources.

Can the forests recover?

While some low-elevation forests and fire-adapted ecosystems may recover, high-elevation and subalpine forests are at risk of permanent change. If temperatures and droughts continue to worsen, regeneration may not occur, and forests may transition to grassland or shrubland.

What can individuals and communities do to help?

Support forest health initiatives, prescribed burns, and pest management projects.
Reduce personal greenhouse gas emissions by conserving energy, choosing renewable sources, and advocating for climate action policies.
Build and maintain defensible space around homes in forested areas, and participate in local wildfire preparedness plans.

Sources

Colorado State Forest Service Annual Forest Health Reports
Recent news and scientific publications on Colorado’s climate and wildfire trends
State and university research on forest carbon cycles

References

Author

Sneha TeteBeauty & Lifestyle Writer

Sneha is a relationships and lifestyle writer with a strong foundation in applied linguistics and certified training in relationship coaching. She brings over five years of writing experience to thebridalbox, crafting thoughtful, research-driven content that empowers readers to build healthier relationships, boost emotional well-being, and embrace holistic living.

Read full bio of Sneha Tete