Table 3 Results of the within-fire analysis for the nine largest fires, summarized for the 500 m radius window scale. Random sample of grid cells within each fire was chosen proportional to fire size. The description of climate context was based on MEI values and identification of major shifts in MEI (see Figure 5). Background geographic information describes the landforms that define topographic variability at each site.

Cerro Grande 2000

(n = 3500)

PLAND

0.24

−0.34

−0.88

Burned in drought conditions that followed the 1997/98 El Niño. Homogeneous topography occurred primarily at low to mid-elevations, with increased heterogeneity at mesa-canyon interfaces and as elevation increased.

AI

0.17

AREA AM

0.18

CAI AM

0.20

DIVISION

0.14

CLUMPY

0.01

Outlet 2000

(n = 1000)

PLAND

0.26

−0.34

−0.88

Burned in drought conditions that followed the 1997/98 El Niño. Relatively little variation in topography on the Kaibab Plateau north of the Grand Canyon.

AI

0.18

AREA AM

0.25

CAI AM

0.29

DIVISION

0.23

CLUMPY

0.02

Pumpkin 2000

(n = 1300)

PLAND

0.10

0.03

−0.81

Burned in less dry conditions, but still within the drought that followed the 1997/98 El Niño. Burned on and around Kendrick Peak, part of the San Francisco Mountains volcanic field. Greatest variance in elevation occurred at highest elevation, where very steep slopes are located.

AI

0.05

AREA AM

0.08

CAI AM

0.11

DIVISION

0.08

CLUMPY

0.03

Viveash 2000

(n = 1800)

PLAND

0.09

0.03

−0.81

Burned in less dry conditions, but still within the drought that followed the 1997/98 El Niño. Network of streams and especially the Pecos River associated with dramatic shifts in topography. Steep mountains, located in the southern end of the Sangre de Cristo Mountains.

AI

0.09

AREA AM

0.06

CAI AM

0.04

DIVISION

0.05

CLUMPY

0.05

Saddle Mountain 1960

(n = 800)

PLAND

0.12

−0.26

0.00

Followed a spike in El Niño (1958–1960) and occurred near the beginning of a negative trend in MEI (i.e., more droughty conditions). The topography creates dramatic relief; high variability occurs where steep scarp slopes, or combs, are adjacent to narrow stream bottoms, and near sheer walls on the south that form the Nankoweap Rim.

AI

0.07

AREA AM

0.15

CAI AM

0.07

DIVISION

0.14

CLUMPY

0.04

Dome 1996

(n = 1350)

PLAND

0.24

−0.49

0.04

Situated in a drought that immediately followed a wetter, El Niño period (ca. 1990–1995). Topographic shifts defined by alternating broad mesas and steep canyons. Capulin Canyon and San Miguel Mountains are areas with the most heterogeneous topography.

AI

0.09

AREA AM

0.21

CAI AM

0.05

DIVISION

0.20

CLUMPY

0.00

La Mesa 1977

(n = 1150)

PLAND

0.21

0.49

0.06

Burned during El Niño and was preceded by an extreme drought (ca. 1974–1976). Topographic variability most dramatic at the edges of steep canyons (Frijoles and Alamo) and broad mesas that define the Pajarito Plateau.

AI

0.07

AREA AM

0.14

CAI AM

0.05

DIVISION

0.15

CLUMPY

0.11

Poplar-Big-Rose 2003

(n = 1400)

PLAND

0.05

0.00

0.58

Occurred during an El Niño phase that began in late 2001–2002. Low topographic complexity on this high-elevation plateau, with some variability around streams and one area of high variability at the edge of the Grand Canyon of the Colorado River.

AI

0.07

AREA AM

0.05

CAI AM

0.06

DIVISION

0.05

CLUMPY

0.04

Oso 1998

(n = 500)

PLAND

0.55

1.14

1.75

Occurred during and was preceded by the historic El Niño of 1997/98. Greatest topographic heterogeneity where broad mesas meet steep canyons, most notably the Santa Clara Canyon.

AI

0.29

AREA AM

0.62

CAI AM

0.64

DIVISION

0.68

CLUMPY

0.17