In A Sonoran Desert Riparian Biome >><< Along Sabino Canyon Creek >><< Saguaro Cactus Reflections In Sabino Pond Above The Dam
Note: The Saguaro Cacti are above the riparian habitat, or riparian biome as it could legitimately be called. www.desertmuseum.org/books/nhsd_biomes_.php
Ecologists who study nature on a global scale recognize a few basic, widespread classes of habitats that are easily identified by their dominant plant life forms, which are basic categories based on general appearance, for example, tree, shrub, annual, succulent, and so on. Such global scale habitats are called biomes, and are determined primarily by the climatic factors of temperature and rainfall. These factors are in turn determined by latitude, elevation, and wind patterns. Biome classification is based on vegetation because plants, being generally immobile, are the most obvious and easily recognizable components of a biological community. In addition, plants are more definitive of their biomes because, since they are rooted in place, they must be adapted to that specific environment. Plants, therefore, are often endemic (occurring only in the named area) to a biome or smaller community. Biomes do contain characteristic animal life as well, including many endemic insects and other invertebrates. Most vertebrates, however, are more mobile and rather few species are restricted to a single habitat.
All of the world's biomes occur in the Sonoran Desert region. This tremendous diversity in a fairly small area is due to two influences. For one thing, this region is on the west side of a continent near 30° North latitude, a position where several biomes typically occur in close proximity (a phenomenon explained later in this chapter). Secondly, our great topographical relief creates the cold, wet climates that allow northern biomes to occur farther south than they would ordinarily.
It is important to recognize that biomes and most other biological classifications are largely subjective concepts. an attempt to make sense of the nearly incomprehensible diversity of nature. In addition, their boundaries are rarely distinct. Wherever two biological communities or biomes meet there is usually a zone of intergradation which is sometimes very wide. For these reasons classifications differ among classifiers. For example, some biologists recognize thornscrub as a separate biome while others call it an ecotone (transition zone) between desert and tropical forest. Some combine tropical and temperate forests into the same biome based simply on vegetation height and density. The biomes as defined here are so distinctive that you should be able to place any terrestrial habitat on the planet within one of them at a glance (see plate 1).
Biomes are subdivided into a hierarchy of smaller categories, defined by the particular species that inhabit them. There are many classification systems and the categories have many names. We use the general terms biotic community, biological community, or simply, community. The names used here for the communities are mostly those of Brown and Lowe (1982).
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The dam was built to create a recreation area for Tucson in the thirties. The pond was a swimming and fishing hole. Now, the pond is very shallow, because soon after the dam was built, flash floods due to heavy rainfall deposited silt in the pool at the dam. The pond was cleared out a few times. Dredging out the pond has ceased. I would love to see it resumed. The silt could be deposited downstream where it would have naturally been deposited if no dan were present.
I would be willing to contribute a modest yearly sum to such a restoration effort should the Friends Of Sabino Canyon organize it.
IMG_3623 - Version 3
In A Sonoran Desert Riparian Biome >><< Along Sabino Canyon Creek >><< Saguaro Cactus Reflections In Sabino Pond Above The Dam
Note: The Saguaro Cacti are above the riparian habitat, or riparian biome as it could legitimately be called. www.desertmuseum.org/books/nhsd_biomes_.php
Ecologists who study nature on a global scale recognize a few basic, widespread classes of habitats that are easily identified by their dominant plant life forms, which are basic categories based on general appearance, for example, tree, shrub, annual, succulent, and so on. Such global scale habitats are called biomes, and are determined primarily by the climatic factors of temperature and rainfall. These factors are in turn determined by latitude, elevation, and wind patterns. Biome classification is based on vegetation because plants, being generally immobile, are the most obvious and easily recognizable components of a biological community. In addition, plants are more definitive of their biomes because, since they are rooted in place, they must be adapted to that specific environment. Plants, therefore, are often endemic (occurring only in the named area) to a biome or smaller community. Biomes do contain characteristic animal life as well, including many endemic insects and other invertebrates. Most vertebrates, however, are more mobile and rather few species are restricted to a single habitat.
All of the world's biomes occur in the Sonoran Desert region. This tremendous diversity in a fairly small area is due to two influences. For one thing, this region is on the west side of a continent near 30° North latitude, a position where several biomes typically occur in close proximity (a phenomenon explained later in this chapter). Secondly, our great topographical relief creates the cold, wet climates that allow northern biomes to occur farther south than they would ordinarily.
It is important to recognize that biomes and most other biological classifications are largely subjective concepts. an attempt to make sense of the nearly incomprehensible diversity of nature. In addition, their boundaries are rarely distinct. Wherever two biological communities or biomes meet there is usually a zone of intergradation which is sometimes very wide. For these reasons classifications differ among classifiers. For example, some biologists recognize thornscrub as a separate biome while others call it an ecotone (transition zone) between desert and tropical forest. Some combine tropical and temperate forests into the same biome based simply on vegetation height and density. The biomes as defined here are so distinctive that you should be able to place any terrestrial habitat on the planet within one of them at a glance (see plate 1).
Biomes are subdivided into a hierarchy of smaller categories, defined by the particular species that inhabit them. There are many classification systems and the categories have many names. We use the general terms biotic community, biological community, or simply, community. The names used here for the communities are mostly those of Brown and Lowe (1982).
_______________________________________________________
The dam was built to create a recreation area for Tucson in the thirties. The pond was a swimming and fishing hole. Now, the pond is very shallow, because soon after the dam was built, flash floods due to heavy rainfall deposited silt in the pool at the dam. The pond was cleared out a few times. Dredging out the pond has ceased. I would love to see it resumed. The silt could be deposited downstream where it would have naturally been deposited if no dan were present.
I would be willing to contribute a modest yearly sum to such a restoration effort should the Friends Of Sabino Canyon organize it.
IMG_3623 - Version 3