Abstract
Dry mixed-conifer forests are widespread in the interior Pacific Northwest, but their historical fire regimes are poorly characterized, in particular the relative mix of low-and high-severity fire. We reconstructed a multi-century history of fire from tree rings in dry mixed-conifer forests in central Oregon. These forests are dominated by ponderosa pine (Pinus ponderosa Lawson & C. Lawson), Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), and grand fir (Abies grandis (Douglas ex D. Don) Lindl.). Across four, 30-plot grids of ~800 ha covering a mosaic of dry mixed-conifer forest types, we sampled 4065 trees for evidence of both high-and low-severity fire. From 1650 to ~1900, all four sites sustained frequent, often extensive, low-severity fires that sometimes included small patches of severe fire (50–150 ha during 18%–28% of fire years). Fire intervals were similar among sites and also among forest types within sites (mean intervals of 14–32 years). To characterize the continuous nature of the variation in fire severity, we computed a plot-based index that captures the relative occurrence of low-and high-severity fire. Our work contributes to the growing understanding of variation in past fire regimes in the complex and dynamic forests of North America’s Interior West.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 76-86 |
| Number of pages | 11 |
| Journal | Canadian Journal of Forest Research |
| Volume | 49 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 1 2019 |
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Keywords
- Dendrochronology
- Fire scars
- Fire severity
- Postfire cohorts
- Severity index
ASJC Scopus subject areas
- Global and Planetary Change
- Forestry
- Ecology
Cite this
A multi-century history of fire regimes along a transect of mixed-conifer forests in central oregon, U.S.A. / Heyerdahl, Emily K.; Loehman, Rachel A.; Falk, Donald.
In: Canadian Journal of Forest Research, Vol. 49, No. 1, 01.01.2019, p. 76-86.Research output: Contribution to journal › Article
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TY - JOUR
T1 - A multi-century history of fire regimes along a transect of mixed-conifer forests in central oregon, U.S.A.
AU - Heyerdahl, Emily K.
AU - Loehman, Rachel A.
AU - Falk, Donald
PY - 2019/1/1
Y1 - 2019/1/1
N2 - Dry mixed-conifer forests are widespread in the interior Pacific Northwest, but their historical fire regimes are poorly characterized, in particular the relative mix of low-and high-severity fire. We reconstructed a multi-century history of fire from tree rings in dry mixed-conifer forests in central Oregon. These forests are dominated by ponderosa pine (Pinus ponderosa Lawson & C. Lawson), Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), and grand fir (Abies grandis (Douglas ex D. Don) Lindl.). Across four, 30-plot grids of ~800 ha covering a mosaic of dry mixed-conifer forest types, we sampled 4065 trees for evidence of both high-and low-severity fire. From 1650 to ~1900, all four sites sustained frequent, often extensive, low-severity fires that sometimes included small patches of severe fire (50–150 ha during 18%–28% of fire years). Fire intervals were similar among sites and also among forest types within sites (mean intervals of 14–32 years). To characterize the continuous nature of the variation in fire severity, we computed a plot-based index that captures the relative occurrence of low-and high-severity fire. Our work contributes to the growing understanding of variation in past fire regimes in the complex and dynamic forests of North America’s Interior West.
AB - Dry mixed-conifer forests are widespread in the interior Pacific Northwest, but their historical fire regimes are poorly characterized, in particular the relative mix of low-and high-severity fire. We reconstructed a multi-century history of fire from tree rings in dry mixed-conifer forests in central Oregon. These forests are dominated by ponderosa pine (Pinus ponderosa Lawson & C. Lawson), Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), and grand fir (Abies grandis (Douglas ex D. Don) Lindl.). Across four, 30-plot grids of ~800 ha covering a mosaic of dry mixed-conifer forest types, we sampled 4065 trees for evidence of both high-and low-severity fire. From 1650 to ~1900, all four sites sustained frequent, often extensive, low-severity fires that sometimes included small patches of severe fire (50–150 ha during 18%–28% of fire years). Fire intervals were similar among sites and also among forest types within sites (mean intervals of 14–32 years). To characterize the continuous nature of the variation in fire severity, we computed a plot-based index that captures the relative occurrence of low-and high-severity fire. Our work contributes to the growing understanding of variation in past fire regimes in the complex and dynamic forests of North America’s Interior West.
KW - Dendrochronology
KW - Fire scars
KW - Fire severity
KW - Postfire cohorts
KW - Severity index
UR - http://www.scopus.com/inward/record.url?scp=85059535758&partnerID=8YFLogxK
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U2 - 10.1139/cjfr-2018-0193
DO - 10.1139/cjfr-2018-0193
M3 - Article
VL - 49
SP - 76
EP - 86
JO - Canadian Journal of Forest Research
JF - Canadian Journal of Forest Research
SN - 0045-5067
IS - 1
ER -