# Presentation: 298720

## Lodgepole Pine Ecology

**Lodgepole Pine Ecology**
**In the Wild...**

**Mike Ryan**
- USDA Forest Service, RMRS
- With help from
**Bill Romme**
- Colorado State University
**Dan Kashian**
- Wayne State University

## The Strife of Lodgepole Pine:

- --- Trail Guide for Arapaho-Roosevelt National Forest

- “In spite of its length, this trail is not strenuous, but is not
- recommended for visitors hoping for scenic vistas or
- heart-warming old-growth forests . . . rather than a grand
- finale, the trail’s final 4.3 miles is mired in monotonous,
- unexciting lodgepole pine forest.”

## The Strife of Lodgepole Pine:

- --- Conversation with Dan Binkley CSU, Spring 2004

- “I was going to comment on how you had to work in nothing
- but aspen forests this summer and how that must have
- become pretty boring.  Then I remembered you used to
- work in lodgepole pine.”

## The Strife of Lodgepole Pine:

- --- District Ranger, Yellowstone National Park, 1988

- “Thank goodness for these fires – we’ll be far better off in
- the long run with more meadows and less lodgepole pine.”

## Lodgepole Pine Ecology

- Life cycle of lodgepole pine forests
- Compare with Ponderosa pine
- Lodgepole pine forests and mountain pine beetle
- Fire and beetles

## Lifecycle – DeathLodgepole forests usually end with a stand replacing fire every 200-350 years

## Lifecycle – RebirthSerotinous cones open after fire and produce many seedlings.  Early cone production (< 15 years) helps fill in any gaps

## Lifecycle – RebirthOther species, such as Snowbrush and reedgrass need fire to thrive and renew

- Snowbrush has dormant seeds;
- reedgrass re-sprouts from
- surviving rhizomes

- Lifecycle – RebirthOther species, such as Snowbrush and reedgrass need fire to thrive and renew

## Lifecycle – Young Stands, 10 years oldTree density varies with serotiny, but regeneration is common

- >20,000 stems/ac

- 350 stems/ac

- 0 stems/ac

## Lifecycle – Young Stands, 50-100 years oldTrees killed in fires have mostly decomposedSelf thinning intense in denser stands

- 4500 stems/ac

- 1200 stems/ac

## Lifecycle – Middle Age Stands100-175 years oldSelf thinning nearly completed, little dead wood unless the stand is very dense

- 1000 stems/ac

- 400** **stems/ac

## Lifecycle – Old Age > 230 years oldMany stands have been attacked by beetlesForest thins as large trees are replaced by new regeneration

- 500 stems/ac

- Beetle killed

## Lifecycle – DeathLodgepole forests usually end with a stand replacing fire every 200-350 years

## Compare Lodgepole to Ponderosa Pine

- Historically open woodlands
- Burned by light surface fires every
- 10 to 30 years

**Notes:**
The lower montane in the county is where ponderosa pine dominates.  Notably, these forests are the type you hear about on the news, and fit this fire suppression model very closely.  (Read slide).  These forest burned very frequently – enough that fire suppression over 100 years may have eliminated 6 or 7 fires that may have otherwise burned.  In many areas – like Cheeseman - fire suppression has resulted dense rather than open ponderosa pine forests, and has made these forests much more flammable than they were in the past.  So, these forests are the type where management such as thinning or prescribed burning may make a big difference – and may direct forest structure back toward the way it used to be, and reduce fire risk at the same time.

## Compare Lodgepole to Ponderosa Pine

- Cones and seeds destroyed in crown fire = poor or no regeneration
- Fire management may reduce risk of crown fire and restore historical forest structure

## Lodgepole versus Ponderosa pine

- Usually has dense stands.
- Crown fire regime at 200 -350 years.

- Fire regime and age structure may be out of balance – but less so than for Ponderosa pine

**Notes:**
The subalpine zone is a little bit of a different world, dominated mainly by lodgepole pine in Larimer County.  Dense stands and large, severe crown fires dominate the landscape, as they probably always have.  These forests burn at very long fire intervals; because they take so long to burn, and burn pretty severely when they do, the fire regimes there are very much they way they always have been, and humans have done little to change things. There have been several fires in Larimer County in the subalpine zone – the Killpecker Fire in 1972, the Pingree Fire in 1994, and even part of the 2000 Bobcat Gulch fire – and all were severe and quite large – and very different from fires that burn in ponderosa pine.

So, short of clearcutting the trees and removing the forest completely, fire management in these forests will probably be pretty useless, and any management will move the forests away from a natural condition rather than restore it – since stands were always dense.  Main point here is that the natural conditions of stands in this forest type are always at high risk of fire– so there is virtually little that fire management can accomplish.

## Lodgepole Pine and the Mountain Pine Beetle: MPB is a native species and outbreaks were common in the past

- Williams and Birdsey 2003

## An extensive outbreak of mountain pine beetle in Colorado – more severe than in the past?  No recent cold winters.

- from Dr. Jeff Hicke,
- University of Idaho

- 1997

- 2005

## Currently, a large amount of lodgepole pine is susceptible to MPB infestation

**Hicke et al.*****, in preparation***

**Currently, a large amount of lodgepole pine is susceptible to MPB infestation**

**Most susceptible stand age (61%)**

## Effects of Bark Beetle Outbreaks in Lodgepole Pine Forests:Conventional Wisdom

- Beetle outbreaks destroy forests
- 2. Beetle outbreaks create huge fuel loads that set the stage for catastrophic fires

## Forest productivity is reduced temporarily 

- Forest productivity is reduced temporarily
- after a bark beetle outbreak ...
- but quickly recovers

- The beetle-caused mortality
- accelerates succession by killing
- the dominant canopy pines
- and releasing the spruce & fir
- in the understory

## Grand Teton NP 

- Grand Teton NP
- 30 yr after outbreak

## Outbreaks create huge fuel loads & set the stage for catastrophic fires ?

- Lodgepole forest is a crown-fire ecosystem
- Normal fire behavior
- Rapid recovery
- Not ecologically catastrophic
- ... but a threat to houses and property in WUI

- Yellowstone,
- 12 years after 1988 fires

##  Hypothesized trends in risk of severe fire following severe bark beetle outbreak in a single-story lodgepole pine forest.

-  Hypothesized trends in risk of severe fire following severe bark beetle outbreak in a single-story lodgepole pine forest.
- 	--  Tinker, Simard, Turner, & Romme

## Large severe forest fires probably pose the greatest threat to life & property in our mountain communities

- This was true before the beetle outbreak, is true now, and will be true in the future
- If fire hazard is reduced temporarily because of the beetles’ thinning, it gives us time to implement treatments that will reduce fire hazards
- The beetles have caught the public’s attention ... an opportunity to act

## Take Home Points

- Lodgepole pine’s lifecycle usually starts and ends with a crown fire.
- Lodgepole pine is *not *Ponderosa pine.  Stands aren’t unnaturally dense and frequent fires not part of their ecology.
- MPB are a natural part of the ecosystem, help lower risk of crown fire and help reset the system.
- Effects of MPB don’t last forever.
- This understanding of LP pine comes from a lot of work by many researchers.