Pinyon Juniper Community

Microbiotic Crust

Ecological roles for biological crusts 1. Fix carbon and nitrogen 2. Trap dust 3. Increase water retention by plants 4. Increase nutrient uptake by plants 5. Safe sites for plant establishment

Pinyon Juniper Woodlands

*also known as "P-J," "elfin" or "pygmy" woodland *5000 feet to 7000 feet in elevation *Annual precipitation is inches (drought and cold adapted) * one of the most widespread habitats in the southwestern United States (between 43 and 100 million acres)

*varying co- dominance of juniper and pinyon pine. Junipers are often the more abundant of the two dominant species Pinyon Juniper Woodlands

Pinus edulis (Pinyon Pine)

Vertical staining from black stain root disease

Ips confusus galleries on pinyon

Juniperus osteosperma Utah Juniper

Pinyon Juniper Communities *Romme et al have proposed three types of pinyon juniper forests for western North America based upon plant community structure and disturbance dynamics 1. Pinyon-Juniper Grass Savanna 2. Pinyon-Juniper Woodland 3. Old-growth Pinyon-Juniper Forests

Pinyon-Juniper Grass Savanna *Fire Regime: frequent, low-severity, surface fires carried by grasses *Pre-1900 Structure: sparse trees, few shrubs, dense grass and other herbs *Post-1900 Changes: Reduced fire frequency, increased fire severity, increased tree density, decreased herbaceous biomass

*Distribution: gentle plains and broad valley bottoms, deep, fine-textured soils, southern NM & AZ and SE Colorado

Pinyon-Juniper Woodlands *Fire Regime: moderately frequent, high- severity, crown fires carried by trees *Pre-1900 Structure: sparse-moderate trees, shrubs, grass and other herbs *Post-1900 Changes: Reduced fire frequency, small increase in fire severity, increased tree density, decreased shrubs and herbs

*Distribution: gentle plains and broad valley bottoms, deep, fine-textured soils, northern Great Basin and Colorado Plateau

Views from Acoma Pueblo to Enchanted Mesa, west of Albuquerque, NM, taken by William Henry Jackson in 1899 and H.E. Malde in 1977

Old-Growth Pinyon-Juniper Forests *Fire Regime: very infrequent, very high- severity, crown fires carried by tree crowns *Pre-1900 Structure: dense trees, sparse to moderate shrubs, sparse herbs *Post-1900 Changes: Little change in fire frequency or severity, tree density, or shrubs and herbs

*Distribution: rugged slopes, canyons, mesa tops, shallow, rocky, coarse-textured soil, scattered on Colorado Plateau, Great Basin, southern Rocky Mountains

Cliff Palace. Photo taken in 1911 by R. W. Berry. Source: USGS Photographic Library, Denver, Colorado.

Mesa Verde National Park 3D map viewed from the East. Sleeping Ute Mountain in the distance.

Knife Edge Road. Photo taken in August 1929 by G. Grant. Source: Mesa Verde Research Center, Mesa Verde National Park.

Spruce Tree Canyon. Photo taken in August 1929 by G. Grant. Source: Mesa Verde Research Center, Mesa Verde National Park.

-usually in PJ where pinyon is dominant--mid- late successional (pine nuts in mature trees) -co-evolved with pinyon trees -nest and cache on south side of trees (warm microclimate for nesting) -use extensive stands for foraging, colony may have up to a 13 sq km (8 sq mi) home range Pinyon Jay