• FIRE ECOLOGY OR ADAPTATIONS
• POSTFIRE REGENERATION STRATEGY

FIRE ECOLOGY OR ADAPTATIONS:

Narrowleaf cottonwood can resprout from the roots, root crown, and/or healthy and fire damaged branches after fire [32]. The ability to resprout from branch fragments may also aid in postfire establishment. Fire generally increases the sediment load in streams when the majority of bank stabilizing vegetation is consumed [35]. Narrowleaf cottonwood branch fragments have the ability to trap sediment for localized deposition by impeding stream flow. Fresh, moist, barren alluvium in full sun is very important in the regeneration of narrowleaf cottonwood [11,18,57].

The role of fire in riparian plant community dynamics is closely related to geology and hydrology. Fire alters erosion processes with the magnitude and scale of effects directly related to the size and severity of fire, the topographical components of the stream system, and the size of stream, in conjunction with the amount, intensity, and timing of postfire precipitation. Streamside soils are highly erodible when the majority of vegetation and duff has been removed by fire. Large amounts of precipitation and other hydrologic events that occur soon after fire may result in drastic channel alteration. However, newly deposited alluvium and changes in channel morphology usually increase habitat complexity [35]. In general, fire-induced channel alterations occur most readily during the first 10 postfire years.

Hungerford and others [49] view the role of fire, in what they refer to as wetland systems, as being closely related to adequate ignition sources, the frequency and duration of favorable fire weather, and annual hydrology. Susceptibility to burning increases when annual dry periods are consistent, especially with the accumulation of dead biomass. Fine dead fuels can burn intensely during periods of low humidity, even when the underlying soil is saturated. Upland ecosystems often dictate the frequency of ignitions [49].

The following table provides some fire regime intervals for communities adjacent to narrowleaf cottonwood:

Community or Ecosystem	Dominant Species	Fire Return Interval Range (years)
silver fir-Douglas-fir	Abies amabilis-Pseudotsuga menziesii var. menziesii	> 200
grand fir	Abies grandis	35-200
maple-beech-birch	Acer-Fagus-Betula	> 1000
sagebrush steppe	Artemisia tridentata/Pseudoroegneria spicata	20-70 [13]
basin big sagebrush	Artemisia tridentata var. tridentata	12-43 [76]
mountain big sagebrush	Artemisia tridentata var. vaseyana	5-15 [93]
Wyoming big sagebrush	Artemisia tridentata var. wyomingensis	10-70 (40)** [90,93]
desert grasslands	Bouteloua eriopoda and/or Pleuraphis mutica	5-100
plains grasslands	Bouteloua spp.	< 35
Rocky Mountain juniper	Juniperus scopulorum	< 35
wheatgrass plains grasslands	Pascopyrum smithii	< 35
blue spruce*	Picea pungens	35-200
pinyon-juniper	Pinus-Juniperus spp.	< 35
Rocky Mountain ponderosa pine*	Pinus ponderosa var. scopulorum	2-10 [13]
quaking aspen (west of the Great Plains)	Populus tremuloides	7-120 [13,37,61]
mountain grasslands	Pseudoroegneria spicata	3-40 (10)**
Rocky Mountain Douglas-fir*	Pseudotsuga menziesii var. glauca	25-100 [2]
elm-ash-cottonwood	Ulmus-Fraxinus-Populus spp.	< 35 to 200 [13]

*fire return interval varies widely; trends in variation are noted in the species summary
**(mean)

POSTFIRE REGENERATION STRATEGY [80]:

Tree with adventitious bud/root crown/soboliferous species root sucker
Initial off-site colonizer (off-site, initial community)

Related categories for SPECIES: Populus angustifolia | Narrowleaf Cottonwood