Physiognomy and Structure: This macrogroup includes open to closed evergreen, needle-leaved conifer or mixed needle-leaved and evergreen broad-leaved forests and woodlands. The upper tree canopy is 15-30 m tall, depending on the dominant tree species, and is typically dominated by needle-leaved conifers. Subcanopy and tall-shrub layers are often dominated by evergreen oaks, pinyon, and juniper trees. Short-shrub and herbaceous layers are often present, but cover varies inversely with tree density and site conditions.

Floristics: This warm-temperate upland macrogroup is characterized by large- and small-patch forests and woodlands that are composed of open to closed evergreen, conifer and mixed conifer-evergreen broad-leaved Madrean forests and woodlands. The upper tree canopy is 15-30 m tall depending on component tree species and is typically dominated or codominated by diagnostic conifers that include Pinus arizonica, Pinus engelmannii, Pinus leiophylla, Hesperocyparis arizonica (= Cupressus arizonica), and at higher elevations by Abies coahuilensis, Abies concolor, Pinus strobiformis, and Pseudotsuga menziesii (or Pinus ponderosa in the northern extent or higher elevations where this macrogroup transitions from a Madrean to southern Rocky Mountain lower montane forest macrogroup, i.e., M022). The typical evergreen oaks in tree canopy included Quercus albocincta, Quercus arizonica, Quercus emoryi, Quercus fulva, Quercus grisea, Quercus hypoleucoides, Quercus rugosa, or Quercus viminea. This macrogroup also includes Arbutus arizonica or Arbutus xalapensis. Other tree species may be present including Juniperus deppeana, Juniperus flaccida, Pinus cembroides, Pinus discolor, and Pinus edulis. An open to moderately dense shrub layer is often present and includes shrub versions of the oak species listed above, chaparral, or montane shrub species such as Agave spp., Arctostaphylos pringlei, Arctostaphylos pungens, Ceanothus fendleri, Cercocarpus montanus, Garrya wrightii, Nolina spp., Quercus toumeyi, and Quercus turbinella. Deciduous oak species, such as Quercus gambelii (incidental) or Quercus x pauciloba may be present. If they are prominent then other Madrean indicator species are present. The herbaceous layer may be sparse to dense depending on overstory canopy density. Open stands often have moderate to dense cover of perennial graminoids, such as Muhlenbergia emersleyi, Muhlenbergia longiligula, Muhlenbergia straminea (= Muhlenbergia virescens), and Schizachyrium cirratum, particularly between trees. More northern, Rocky Mountain cool-season elements occur occasionally and include Bromus ciliatus var. richardsonii (= Bromus richardsonii), Carex geophila, Koeleria macrantha, and Poa fendleriana. The typically sparse forbs are present including Comandra umbellata, Galium tinctorium, Hedeoma hyssopifolia, Lathyrus graminifolius, Mirabilis comata (= Oxybaphus comatus), Packera neomexicana, Thalictrum fendleri, and Vicia americana.

Dynamics:  Under historic natural conditions (also called natural range of variability, NRV), lower to mid-elevation stands in this macrogroups varied from open woodlands (10-20% cover) with pines dominating the overstory and perennial bunch grass dominating the understory to moderately dense woodlands (20-40% tree cover) with less dense herbaceous layer and more tree and shrub cover. Lower elevation tree line of pines is primarily controlled by dry season water stress (Barton 1993). Fire and drought are the primary disturbances of this ecosystem (USFS 2009).

Information on fire return intervals is varied depending on elevation zone with fires frequently starting at lower elevations and burning upslope into the montane zone. Lower montane elevation pine-oak stands had frequent, low intensity surface fires (mean fire return every 6-14 years) as a result of lightning ignitions primarily between early spring and summer (Bahre 1985, Swetnam et al. 1992, 2001, Kaib et al. 1996, Schussman and Gori 2006, Swetnam and Baisan 1996b). However, minimum fire-free periods of 20-30 years are necessary for pines to establish and become resistant (thick bark) to surface fires (Barton et al. 2001). More frequent fire favors oaks and other sprouting species over pines and other conifers, which can alter stand composition. Less frequent fire (FRI >50 years) results in more conifer recruitment and denser vegetation that can lead to higher intensity, mixed-severity and patches of stand-replacing fires that also favors oaks and other sprouting species (Danzer et al. 1996, Barton 1999, Barton et al. 2001, Schussman and Gori 2006). For stands with inclusions of Ponderosa Pine Woodland in the Madrean Conifer-Oak Forest and Woodland, the historic mean fire-return interval is similar (Smith 2006). In Arizona and New Mexico, Swetnam and Baisan (1996b) found the historic mean fire-return interval ranges from 2 to 17 years for fires scarring one or more trees, and 4 to 36 years for fires scarring between 10% and 25% of trees between the years of 1700 and 1900. However, in the more mesic subalpine fir communities a fire return interval of up to 400 years is not uncommon.

Herbivory by native herbivores in the Madrean montane conifer-oak forests and woodlands is variable in this type. For more open stands with grass-dominated understory herbivores are similar to semi-desert grasslands. Large herbivores include browsers like Coues'' white-tailed deer (Odocoileus virginianus couesi), mule deer (Odocoileus hemionus), elk (Cervus elaphus), and rodents such as yellow nosed cotton rat (Sigmodon ochrognathus), white-throated wood rat (Neotoma albigula), southern pocket gopher (Thomomys umbrinus), Apache squirrel (Sciurus nayaritensis), Arizona gray squirrel (Sciurus arizonensis), porcupine (Erethizon dorsatum), Bailey''s pocket mouse (Chaetodipus baileyi), and eastern cotton tail (Sylvilagus floridanus) are common in the Madrean pine-oak woodlands (Schussman and Gori 2006, Majka et al. 2007). Southwestern forest trees have been host to several species of insects, pathogenic fungi, and parasitic plants, however there are no accounts of historic insect outbreak, fungi or parasitic plant periodicity (Dahms and Geils 1997).

A good condition/proper functioning occurrence of Madrean Montane Conifer-Oak Forest and Woodland ecosystem is large and uninterrupted; the surrounding landscape is also in good condition with soils that have not been excessively eroded. Weeds are few. There is a diversity of stand age and size classes in response to a functioning natural fire regime. For the majority of the type (lower montane pine-oak woodlands) that is frequent (mean fire return every 6-14 years), low-intensity surface fires with occasional fire free periods of 20-30 years minimum to allow for conifers to establish and become resistant (thick bark) to surface fires. For upper montane conifer oak and mixed conifer forests, the historical fire regime would have less frequent fires, mixed-severity and occasional stand-replacing fires.

A poor condition/non-functioning occurrence is highly fragmented, or much reduced in size from its historic extent; the surrounding landscape is in poor condition either with highly eroding soils, many non-native species or a large percentage of the surrounding landscape has been converted to exurban development. Over time passive (livestock grazing) and active fire suppression would result high density of trees and heavy fuel loading that would lead to large, high-severity, stand-replacing fires in stands of the montane conifer-oak forests.