Flora

Aug 07,2016
The Rocky Mountains are the backbone of North America and divide the state in half creating the Eastern and Western slopes. Two-fifths of the state are on the Eastern slope and are part of the Great Plains, which means that 40 percent of Colorado is non-mountainous. Colorado's Western slope and mountain ranges have 13 National Forests.There are around 3,500 native plant species in Colorado. 3,200 are flowering plants and more than 500 of them are rare. The mountains cause a number of climatic storms that eventually cross the Eastern plains of Colorado where a wide variety of plants and grasslands grow. There are over 500 types of wildflowers on the plains.Plants are separated into 3 categories: trees, shrubs and herbs. The 2 types of trees are coniferous and deciduous. They are long lived and normally taller than 16 feet. Shrubs survive several seasons and are normally less than 16 feet tall. Herbs are non-woody plants.Weeds are the most common wildflowers along roads and in fields which originated in Europe and Asia. Although many are very pretty, they are troublesome pests and a threat to plant communities in the wild.Colorado is made up of 8 distinct ecosystems that have a large variety of landscapes, flora and fauna. Ecosystem refers to the physical environment and all the organisms in a given area. Each ecosystem is unique in its combination of geology, climate, elevation, latitude, slope direction and slope angle that creates environments for specific plants and animals. The growing environments are called Life Zones of vegetation according to the elevation in Western America.
ALPINE (Tundra) ZONE: (11,400 feet elevation and above).
This zone comprises of bare rocks, tundra and alpine meadows above tree line. The temperature is just high enough for enough days to permit vegetative growth. Fewer species of plants and animals survive in the alpine than in other eco-regions. Species must grow and reproduce in a short growing season and be able to withstand strong winds and intense sunlight. The flora in this zone consists primarily of tundra grasses, mosses, sedges and lichens. Perennial wildflowers also grow here, but are no more than a couple of inches.
SUBALPINE (Forest) ZONE: (9,000 to 11,400 feet in elevation).
This zone exists upward from the upper edge of the Montane zone to tree line. Mid-elevation slopes have heavy forests with cool, damp, mossy forest floors and receive the heaviest snow accumulation. The subalpine is what most people envision when they think of the Rocky Mountains.
MONTANE (Forest) ZONE: (5,600 to 9,000 feet in elevation).
This zone consists of the lower slopes and valleys above the foothills. The Western slopes are wetter, heavier and shrubbier compared to the drier Eastern slopes. The Montane also holds the greatest variety of wildflowers, trees and shrubs. The majority of this zone has Ponderosa Pines, Douglas Firs, Lodgepole Pines, Spruce, Aspen and the Rocky Mountain Juniper. It is in the Montane that the heaviest effects of human encroachment occur. The Montane is a threatened eco-region in need of protection and restoration.
MONTANE (Shrubland) ZONE:
Montane Shrublands are found at 5,500 to 10,000 feet on the Western Slope. Montane Shrublands represent a transitional zone between the Grasslands and Montane Forests. Usually found on dry, rocky foothill sites. Montane Shrublands have a mix of vegetation from grasses to scattered Pinon Pine or Ponderosa Pine trees. Mountain Mahogany, Gambel Oak, Scrub Oak and many shrubs thrive in this zone as well.
PINON-JUNIPER WOODLAND ZONE:
The Pinon-Juniper Woodland lies in the transition zone between Grasslands or Shrublands and lower than the Montane (Forest) Zone at elevations from 5,500 feet to 8,000 feet. They are primarily found in the Western part of Colorado. The ground cover between the trees is sparse with a variety of grasses, shrubs and flowering plants. This zone is also called the High Desert.
SEMI-DESERT SHRUBLAND ZONE:
Extends up to 8,000 feet in elevation on the Eastern slope and 7,000 feet on the Western slope. Plants here are low growing, drought tolerant and deciduous shrubs. The soil is often alkaline, has poor water infiltration and high runoff. The most widespread type of semi-desert shrubland is the sagebrush steppe. The first elevation slopes before the treed Montane slopes are considered the Foothills. The Foothills are generally low-elevation shrublands that blend into the prairies.
GRASSLAND ZONE: (4,000 to 10,000 feet elevation).
The grasslands on the plains cover the Eastern third of Colorado and is made-up primarily of short-grass species. The climate is hot in the summer and varies in the winter. It is still one of the most intact grasslands remaining in the Great Plains region. Agriculture and urban development have impacted the health of prairies and few areas in Colorado retain a truly native ecosystem. This zone is the only one that is technically not part of the Rocky Mountains. They lie in the rain shadow east of the Rockies and blend into the foothills, but do not form a definite zone within the mountains.
RIPARIAN SYSTEMS:
The term riparian area refers to the interface between a river or stream and the upland landscape. Riparian habitats are those found along rivers and other watercourses and they have the greatest biodiversity of any habitat in the West. Colorado has fairly distinct low-altitude, medium-altitude and high-altitude riparian zones. The lower habitats are mostly east and have Plains Cottonwoods and underbrush. The medium habitats usually have Narrow-leaf Cottonwoods, River Birch, Alder, Willow and Blue Spruce. The Valley Cottonwood is found on the Western Slope. The higher habitats have low-growing willows. Riparian areas are found at all elevations and within all ecosystems of the state from the Grasslands to the Alpine tundra.
Colorado Mountain Man