Archive for the ‘Biodiversity’ Tag

Draught In The Canyon   Leave a comment

Intense Drought In Sabino Canyon — Image by kenne

The Sonoran Desert
known for its biodiversity
having two rainy seasons

the summer monsoon
and winter rainy season
now experiencing drought.

Normal drought conditions
made worse by La Niña
event reducing rainfall.

Many native plants are dying
vegetation green-up is poor
during this intense drought.

— kenne


Anna’s Hummingbird   2 comments

Hummingbird - Youth blogFemale Anna’s Hummingbird — Image by kenne

Lack of rain in the Sonoran Desert has reduced the amount of food available for hummingbirds — very few wildflowers this year. But my lemon tree, which is in bloom has been attacking several of these small birds. Plus, I’m not sure how the warmer than normal has affected migration. 

Here in Tucson, you can see hummingbirds year-round in riparian areas and backyards. We are fortunate to have The Paton Center for Hummingbirds, a place to explore and experience the special birds of southeast Arizona. It is dedicated to the celebration and conservation of hummingbirds—and all of southeast Arizona’s astounding biodiversity—through recreation, education, and sustainable living.

— kenne

Arizona Upland — The Saguaro-Palo Verde Forest   7 comments

We live in the Sonoran desert. For most people, when they hear the term “desert” they picture a dry, desolate wasteland. However, the term defines a wide spectrum of diverse landscapes, plants, and animal populations.

“A concise nontechnical definition of a desert is ‘a place where water is severely limiting to life most of the time.'” (A Natural History of the Sonoran Desert) The Sonoran desert is divided into seven subdivisions based on the diverse vegetation found in 100,000 sq. miles that include much of the Mexican state of Sonora, most of southern Arizona, southeastern California, and most of the Baja California peninsula.

Tucson and most of the Pima county area are in the Arizona Upland subdivision, which is the highest and coldest part of the desert — also called the “saguaro-palo verde forest.” The diversity of this area is partly explained by the two equal rainy seasons.

More and more, biologists are concluding that the Arizona Upland’s climate, vegetation density, and biodiversity resemble a thorn scrub biomes more than desert biomes, which might explain why many refer to this area as the “lush” desert. By any name, this is a very special place. Still many people who visit and/or move to Tucson complain about what they see as a lack of seasons, when in fact the Arizona Upland has five seasons: summer monsoon; autumn; winter; spring; foresummer — they’re just more subtle.

The defining form of the Arizona Upland is the saguaro cactus. I first fail in love with the area and its giant saguaro cactus in the late ’60s, during which time I read of the imminent demise of this iconic symbol of southern Arizona. Upon my return, some forty years later, I learned that such impending doom was no more than a modern myth, although soundly refuted refuses to die. As written in A Natural History of the Sonoran Desert, “The misinterpretation might be analogous to a situation in which extraterrestrials briefly visit the earth and collect a sample of people from a nursing home.”

Like with most species of desert plants there is an ebb and flow in the ecosystem. Declines are often caused by severe freezes or droughts. Since much of the west has been in a ten-year drought, it is not surprising that a decline may currently exist. “In the occasional wet years, mass recruitment reverses the trend of decline with a reproductive boom. In the case of saguaros, these episodes of net recruitment seem to occur less than a half-dozen times per century in the Saguaro National Park (west), and less often in the drier regions.” (A Natural History of the Sonoran Desert)

— kenne

Images by kenne

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