wm

Biomes and Biotic Communities : 

Biomes and Biotic Communities

Biome: General worldwide vegetation patterns defined by types of plants more than by particular species. : 

Biome: General worldwide vegetation patterns defined by types of plants more than by particular species. DesertGrasslandDeciduous ForestTropical rainforestEvergreen woodlandArctic tundra

There are marine biomes as well, but often identified by animal life : 

There are marine biomes as well, but often identified by animal life Tidal zonesCoral reefsAbyssSaltwater marsh

Slide 4: 

Moisture is generally the overriding factor determining the type of biome that may be supported by an area. Given adequate moisture, an area will likely support a forest. Temperature, however, determines the kind of forest. The situation is similar for grasslands and deserts. At cooler temperatures, there is a shift toward less precipitation because lower temperatures reduce evaporative water loss.

Biotic Community: (Life Zone) Any assemblage of plant or animal populations living in a prescribed area or physical habitat, defined by common plant or animal species, and limited by common environmental factors. These environmental factors are generally climate, but can include soil type, aspect, etc. : 

Biotic Community: (Life Zone) Any assemblage of plant or animal populations living in a prescribed area or physical habitat, defined by common plant or animal species, and limited by common environmental factors. These environmental factors are generally climate, but can include soil type, aspect, etc.

C. Hart Merriam did much of the early work describing biomes and biotic communities in Arizona : 

C. Hart Merriam did much of the early work describing biomes and biotic communities in Arizona

Slide 8: 

Major geographic variables that affect available moisture, which in turn affect distribution of plant species: Latitude: The further north you go the cooler it will be. In general more moisture will be available to plants as well. In Canada, Hudsonian plant community occurs at sea level. Elevation; The higher up you go in elevation, the wetter and cooler it will be. In Arizona, Hudsonian plant community occurs over 9,000' in elevation, but does not occur at 200'. Aspect; It will be wetter and cooler on northeastern slopes than on southwestern slopes because slopes that are more exposed to the sun’s radiation will be hotter and drier. Hudsonian community would occur at a lower elevation on a northern exposure hillside.

The effect of aspect : 

The effect of aspect

Major factors contributing to diversity of Arizona’s biotic communities: : 

Major factors contributing to diversity of Arizona’s biotic communities: Weather Two rainy seasons. Temperature extremes. Rainfall extremes. Diverse topography. Extremes in elevation. Diverse soils. Geography Situated between the temperate and tropical parts of North America. Biogeographic history, former ice ages, etc.

Arizona has 4 desert types : 

Arizona has 4 desert types Sonoran Mohave Great Basin Chihuahuan

Sonoran Plants : 

Sonoran Plants Palo Verde, Ocotillo, Saguaro, Organ Pipe, Brittle Bush, Creosote Bush

Large distinction between lower and upper : 

Large distinction between lower and upper

Sonoran Animals (small game) : 

Sonoran Animals (small game) Both dove species Gambel’s quail desert cottontail (Sylvilagus audubonii)

Chihuahaun Desert : 

Chihuahaun Desert Acacias Creosote, Ocotillo, and yuccas

Mohave desert : 

Mohave desert Creosote Bush, Joshua Tree, Yuccas, Black Brush, and Bladder Sage

Great Basin Desert Scrub : 

Great Basin Desert Scrub Big Sagebrush Mormon tea Greasewood Snakeweed

Grasslands and Interior Chaparral : 

Grasslands and Interior Chaparral

Alpine Grasslands : 

Alpine Grasslands I’m including Montane Meadow in this classification

Plains Grassland : 

Plains Grassland Most Common species is Blue Grama (Bouteloua gracilis), others include Great Basin species such as Hilaria jamesii, and Oryzopsis hymenoides; shrubs include 4 wing saltbush and smaller yucca species NE AZ, Eastern Coconino County into Apache and Navajo Much of it has been invaded by junipers

Semidesert Grassland : 

Semidesert Grassland Is strongly associated with Chihuahuan Life Zone Common grass species include: Tobosa grass (Hilaria mutica), Sacaton (Sporobolus wrightii); exotic Lovegrass (Eragrostis spp.) has done well there; shrubs depend on Chihuahuan or Sonoran influence

Sonoran Savanna : 

Sonoran Savanna Larger valleys in SE AZ and northern, strong association with fire, frequently invaded by mesquite

Interior Chaparral : 

Interior Chaparral Several AZ species different from California coastal chaparral-but both “Mediterranean” Several species of Quercus-scrub oak most common, Manzanita, Silktassel Arizona cypress

2 lower elevation forests : 

2 lower elevation forests Pinyon-Juniper Madrean Woodland

Pinyon-Juniper : 

Pinyon-Juniper Pinyon Pine Alligator, One seeded, and Utah Juniper Can be associated with great basin, chihuahuan, or chaparral vegetation associations

Madrean Evergreen Forest : 

Madrean Evergreen Forest Encinal Woodland with several evergreen oak species, Emory, Wright, Silver, etc. Often intergrades with chaparral in SE and Central AZ Sky Islands

3 high elevation forests : 

3 high elevation forests Ponderosa Pine Douglas Fir (mixed conifer) Spruce-Fir

Ponderosa Pine (Rocky Mountain Petran) : 

Ponderosa Pine (Rocky Mountain Petran) Ponderosa Pine Gambel Oaks very important for wildlife

Douglas Fir (Mixed Conifer) : 

Douglas Fir (Mixed Conifer) Douglas, White, and Alpine Firs, and Aspen Some Ponderosas

Spruce Fir : 

Spruce Fir Engelmann and Blue Spruce Alpine and Corkbark firs

Alpine Tundra : 

Alpine Tundra Only found on San Francisco Peaks in AZ Sedge-grass mixture

And our most precious, that we have lost the most of, Riparian : 

And our most precious, that we have lost the most of, Riparian