Appendix CAS. The Cascade Ranges Region

The volcanic Cascade Ranges Region (Figure CAS-1) encompasses 20,681 km² between the Oregon border on the north and the Sierra Nevada region on the south. The primary topographic features are the volcanic cones of Mount Shasta and Lassen Peak. The southern boundary near the North Fork of the Feather River is marked by the contact between the recent volcanic rock of the Cascades to the older metamorphics of the Sierra. Similarly, the boundary on the west with the Northwestern California region is a contact zone with predominantly metamorphic rock near the Sacramento River and Interstate 5. The Modoc Plateau region lies to the east in the rainshadow of the Cascades. South of Red Bluff, the region adjoins the Great Central Valley with its agriculture and California prairie community compared to the chaparral and foothill woodlands in the Cascades. Vegetation does not generally display distinct breaks at the geologically defined boundaries with the Sierra and Northwestern California and the climatically defined boundary with the Modoc Plateau.

The region has the third lowest proportion of lands in status 1 or 2 managed areas (Table CAS-1). At 7.1%, the Cascade Ranges region exceeds only the Modoc Plateau and the Great Central Valley. The predominant blocks of lands managed for biodiversity in the region are Lassen Volcanic National Park-Caribou Wilderness and the Ishi Wilderness/Tehama Wildlife Area/Gray Davis-Dye Creek Preserve complexes. The latter is one of the few large protected sites in the foothill zone of California.

Status	Area (km²)	%
1	1,095	5.3
2	380	1.8
3	7,921	38.5
4	11,187	54.4
Total	20,583	100.0

CNDDB Code	CNDDB Community Name (Holland 1986)	CNDDB Rank	Status 1 %	Status 2 %	Status 3 %	Status 4 %	Total Mapped Distribution (km²)	Status 1+2 %
35100	Great Basin Mixed Scrub	S4	0.6	0.3	58.5	40.6	279.8	0.9
35210	Big Sagebrush Scrub	S4	0.0	2.4	72.2	25.0	198.1	2.4
35211	Low Sagebrush Scrub *	--	0.0	0.0	48.7	51.3	7.8	0.0
35220	Subalpine Sagebrush Scrub	S3.2	0.0	0.2	82.8	17.0	68.3	0.2
35400	Rabbitbrush Scrub	S5	0.0	0.0	61.4	38.6	15.0	0.0
35500	Cercocarpus ledifolius Woodland *	--	1.5	0.1	46.2	52.2	39.9	1.6
37110	Northern Mixed Chaparral	S4	25.3	8.4	29.6	36.7	37.4	33.7
37510	Mixed Montane Chaparral	S4	1.5	0.0	25.3	73.2	52.9	1.5
37520	Montane Manzanita Chaparral	S4	3.7	1.0	48.2	47.1	395.1	4.7
37530	Montane Ceanothus Chaparral	S4/3.3	0.9	0.5	34.5	64.1	260.6	1.4
37541	Shin Oak Brush	S3.3	4.1	7.1	51.5	37.3	128.1	11.2
37550	Bush Chinquapin Chaparral	S3.3	14.8	0.0	47.6	37.6	92.1	14.8
37810	Buck Brush Chaparral	S4	6.7	7.0	13.8	72.5	80.2	13.7
37A00	Interior Live Oak Chaparral	S3.3	0.8	0.0	14.8	84.4	55.8	0.8
37E00	Mesic North Slope Chaparral	S3.3	0.0	0.0	78.1	21.9	13.2	0.0
42200	Non-Native Grassland	S4	0.4	1.8	2.7	95.1	527.4	2.2
43000	Great Basin Grassland	S1.1	0.0	0.0	30.6	63.7	0.8	0.0
45100	Montane Meadow	S3.2	0.0	0.7	39.0	60.3	105.4	0.7
45200	Subalpine or Alpine Meadow	S3.2	0.6	15.4	48.8	35.0	47.8	16.0
61410	Great Valley Cottonwood Riparian Forest	S2.1	0.0	0.0	12.5	87.5	2.5	0.0
61420	Great Valley Mixed Riparian Forest	S2.2	17.7	2.5	1.3	78.5	18.8	20.2
61430	Great Valley Valley Oak Riparian Forest	S1.1	0.0	0.0	4.6	95.4	4.2	0.0
61510	White Alder Riparian Forest	S4	0.0	0.0	0.0	100.0	13.8	0.0
61610	Modoc-Great Basin Cottonwood-Willow Riparian Forest	S2.1	0.0	0.0	100.0	0.0	11.4	0.0
63500	Montane Riparian Scrub	S4	0.0	0.0	18.0	82.0	15.7	0.0
71110	Oregon Oak Woodland	S3.3	0.2	0.9	28.9	70.0	223.3	1.1
71120	Black Oak Woodland	S3.2	0.8	4.7	41.2	53.3	232.4	5.5
71130	Valley Oak Woodland	S2.1	0.0	0.0	13.4	86.6	6.4	0.0
71140	Blue Oak Woodland	S3.2	13.7	9.2	3.7	73.4	758.4	22.9
71150	Interior Live Oak Woodland	S3.2	1.5	4.8	26.3	67.4	148.8	6.3
71310	Open Foothill Pine Woodland	S4	11.5	7.8	8.8	71.8	622.1	19.3
71322	Non-Serpentine Foothill Pine Woodland	S4	5.5	3.5	15.7	75.4	158.0	9.0
71410	Foothill Pine-Oak Woodland	S4	4.3	1.0	8.1	86.6	843.4	5.3
71430	Juniper-Oak Cismontane Woodland	S3.2	0.0	0.1	14.0	85.9	135.9	0.1
72100	Great Basin Woodlands	S3.2/4	0.0	1.8	40.2	57.9	1,199.3	1.8
81320	Canyon Live Oak Forest	S4	15.9	0.0	36.1	48.0	85.1	15.9
81330	Interior Live Oak Forest	S4	0.0	1.1	35.1	63.8	64.5	1.1
81340	Black Oak Forest	S4	2.3	0.1	40.6	56.9	473.6	2.4
81400	Tan-Oak Forest	S4	0.0	0.3	62.0	37.7	11.7	0.3
83210	Knobcone Pine Forest	S4	0.0	0.0	83.8	16.2	32.2	0.0
84210	Westside Ponderosa Pine Forest	S2.1	4.4	1.1	45.3	49.2	2,347.3	5.5
84220	Eastside Ponderosa Pine Forest	S2.1	2.4	1.5	60.6	35.5	1,821.5	3.9
84230	Sierran Mixed Coniferous Forest	S4	2.1	0.4	39.4	58.1	5,507.1	2.5
84240	Sierran White Fir Forest	S4	1.9	2.7	36.9	58.4	196.6	4.6
85100	Jeffrey Pine Forest	S4	3.8	5.9	66.4	23.9	47.7	9.7
85210	Jeffrey Pine-Fir Forest	S4	23.8	0.3	54.5	21.5	419.2	24.1
85310	Red Fir Forest	S4	26.4	2.0	55.6	16.1	761.1	28.4
86100	Lodgepole Pine Forest	S4	24.6	0.5	58.1	16.8	238.9	25.1
86210	Whitebark Pine-Mountain Hemlock Forest	S4	48.2	0.0	19.0	32.8	52.4	48.2
86600	Whitebark Pine Forest	S4	91.5	0.0	5.6	2.9	7.9	91.5
91110	Klamath-Cascade Fell-field	S4	94.1	0.0	4.8	1.1	54.1	94.1
	Regional Total-Natural Communities						18,921.2
	Regional Total (incl nonvegetated)		5.3	1.8	38.5	54.4	20,679	7.1

We call attention to three categories of poor representation and one in which types appear to be well protected. Table CAS-2 gives the area of mapped distribution and proportions in each management level for every community type.

1. Plant community types occurring mainly on status 4 lands. Only Non-Native Grassland has a mapped area greater than 25 km² in the region with more than 90% in status 4 lands (primarily privately owned). This type mostly occurs in the lower elevations adjacent to the Great Central Valley. Interior Live Oak Chaparral, Foothill Pine-Oak Woodland, and Juniper-Oak Woodland have greater than 80% in status 4. The Juniper-Oak Woodland type is composed of California juniper with shrubby blue oak. It is generally restricted to the Inner Coast Ranges between Ventura County and Mt. Diablo (Holland 1986), and its occurrence north of Red Bluff near the region boundary is an unusual outlier from the main distribution.

2. Scrub, chaparral, and herbaceous types mainly located in unprotected areas. Virtually all of the Great Basin scrub communities (Great Basin Mixed Scrub, Big Sagebrush Scrub, Subalpine Sagebrush Scrub, and Cercocarpus ledifolius Woodland) and the montane chaparral types (Mixed Montane Chaparral, Montane Manzanita Chaparral, and Montane Ceanothus Chaparral) are poorly represented in status 1 or 2 managed areas of the Cascade Ranges region (all under 5%). Interior Live Oak Chaparral, Non-Native Grassland, and Montane Meadows have similar low representation. The concerns for most of these types are the potential impacts of grazing and invasions of exotic plant species on native ecosystems. Interior Live Oak Chaparral, Mixed Montane Chaparral, and Subalpine Sagebrush Scrub, however, occur more extensively in other regions.

3. Forest and woodland types mainly located in unprotected areas. Most of the woodland and lower elevation forest types have low levels of representation in this region. These include Oregon Oak Woodland, Interior Live Oak Woodland and Forest, Black Oak Woodland and Forest, Non-Serpentine Foothill Pine Woodland, Foothill Pine-Oak Woodland, and Juniper-Oak Cismontane Woodland of the broadleaf or mixed types. The conifer types that are poorly represented are the Great Basin Woodlands on the eastern side of the region and Knobcone Pine Forest, Westside and Eastside Ponderosa Pine Forest, Sierran Mixed Coniferous Forest, Sieran White Fir Forest, and Jeffrey Pine Forest. These types are of management concern because timber harvest and/or grazing prevail on both public and private lands where these communities occur. Blue Oak Woodland and Open Foothill Pine Woodland tend to be poorly represented in managed areas in other parts of the state, but in the Cascades, relatively high percentages of their distributions occur in the large complex (Ishi/Tehama/Gray Davis-Dye Creek) of low elevation managed areas.

4. Community types that appear well-protected. Five community types in this region are relatively well-represented (i.e., > 25% in status 1 or 2). Most of these are the upper montane, subalpine, or alpine types (Red Fir, Lodgepole, and Whitebark Pine-Mountain Hemlock Forests and Klamath-Cascades Fell-field). This pattern reflects the high proportion of land at higher elevations managed as wilderness or national park in this region. The other well-represented type is Northern Mixed Chaparral.