Archive for the ‘Sonoran desert’ Category

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Why Beans?

April 18, 2014

If you start investigating Sonoran Desert plants, including trees and shrubs, you’ll find quite a few members of the bean family (Fabaceae) represented.

Palo Verde blossoms

Palo Verde blossoms

That may seem surprising. Why beans? At first glance, your average garden variety green bean plant does not seem especially deserty.

So let’s start with a hidden feature that might be useful in a desert—to deal with poor soil, beans have come up with a clever friendship—they have symbionts, associates, little bacteria that live in nodules, little bumps, in their roots. The beans provide water and sugars to the bacteria, and the bacteria “fix” nitrogen from the soil, turning it into a form the bean plants can use.

And that’s one reason beans are good for you—because of the nitrogen from their little friends, they can make certain essential amino acids, parts of proteins.

Grains like corn or wheat or rice make different amino acids. And it is important for us to eat them together with legumes, another name for beans, to get whole nutrition in one meal. So, for example, we dine on beans and rice, or beans in corn tacos or wheat tortillas, or baked beans with toast, or even a peanut butter sandwich, since peanuts are also a legume.

Humans figured this out a long long time ago, and in fact, they even grew grains and beans together. An essential core of Native American gardens all over North and South America was the trio of beans, corn and squash. The corn provides scaffolding for the beans to climb, and the remains of the bean plants are a source of usable nitrogen for the next year’s corn and squash. To this day, these three continue to play a big role in our gardens, as well as in those huge gardens known as farms.

It turns out that beans also have a bunch of other cool skills for the hot desert—stay tuned!

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Packrat Middens

November 3, 2013

Packrats, Neotoma albigula, make interesting nests in which to store their treasures—and themselves.

When you are out in the desert, the trick is how to spot a packrat nest. It’s not always easy. I guess that’s the idea, when you are building a hideaway.  Basically, look for a crazy, almost random pile of sticks and leaves, and often cholla cactus stems. The nests can range from a foot to 8 feet wide, and are often at the base of a shrub or cactus.

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Apparently, If you went inside a packrat nest or midden, an activity the packrats vigorously discourage, you might find shiny bits of human treasures—foil, metal, or other bright objects, since packrats seem to like shiny things as much as we do.

Packrats do like cholla cacti, somehow managing to avoid their really nasty and determined thorns. There’s even one variety called the jumping cholla—I would stay away from those! The name comes from how easily a stem can get detached and glom onto you. A packrat favorite! Cholla stems are certainly a good defensive addition to a habitation—the dry stems are probably even nastier than green ones. According to the Desert Museum, packrats love to eat prickly pear fruit. So they are really cactus creatures.

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Limiting Factors—Cold!

February 4, 2013

If you were in the Sonoran desert in January 2013, you may well have experienced a limiting factor that many people would not expect in a desert: freezing damaging cold.

In many places it dropped into the 20’s or lower at night, for several nights, enough to nip many buds in the bud.

Native plants, which have been through this before, generally survived quite well, but imports, or annual vegetables, either got crisped or completely melted down.

This suggests that planting native species has even more benefits than we usually consider.

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Herds of Callipepla gambelii

November 20, 2012

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For a long time through the summer, when you saw Gambel’s Quail, Callipepla gambelii, in the Sonoran desert, you’d usually see just one or two individuals.

Then in late summer, there were groups of 4 or 5.

As the weather cooled (well, cooled relatively speaking—this is a southern desert) and autumn officially started, suddenly there are huge herds of up to 20 quail. Yes, I know, covey, more accurately, coveys of quail.

In the new year, they will pair off, the big groups will disperse, then new family herds of mom, dad, and sometimes more than a dozen little peepers, who are amazingly fast soon after hatching, will appear on the scene.

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Ocotillos and Verdins

April 23, 2012

This has been a banner year for ocotillos in the Sonoran desert. They started blooming a couple of weeks ago, and have erupted into full orange color. That’s Fouquieria splendens, for all you science types!

Their nectar attracts a variety of insects, making them a favored landing spot for the small olive yellow birds, the verdins (Auriparus flaviceps.) Look for verdins visiting all kinds of flowering plants throughout the summer and fall.

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Haboob, the Desert Dust Storm

July 8, 2011

Another limiting factor in the desert arises from the ferocious dessicating and abrasive desert dust storm called the Haboob. Often associated with the seasonal monsoons, these storms can actually happen any time of year, blasting and scouring any plants and animals in their path.

The word haboob is Arabic, from the home of truly impressive sandstorms, but now is applied in any area susceptible to them.

These storms can move particles of dust and even sand, and may reach hurricane force for a few minutes at a time.

Deserts have few trees to stop the wind, and little moisture to hold down the soil. A haboob forms when warm air rises into thunderheads, then the air is cooled by rain, the storm collapses, and the cooled air falls and rushes out from the base of the storm, driving dust and sand before it, sometimes at truly remarkable speeds. Within minutes, winds can go from zero to 50 miles an hour.

Dust storms often arise suddenly, making them hard to avoid or escape. Most years in the Sonoran desert, there are traffic accidents associated with dust storms, when visibility suddenly plummets.

Desert plants need either shelter or thick skins to handle the dessication and scouring associated with a haboob or other winds.

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A Dry Heat

June 29, 2011

The joke is, in the Sonoran desert, even though it’s 114, it’s a dry heat.

The idea being that with very low humidity, amazingly, under 5 percent at times, the heat is easier to bear.

114, an average high for a few days each summer, is still bad enough, but given how few trees and other shelter there is in the desert, it’s almost always a sunny heat during the daytime, which adds another 7 to 10 degrees.

All plants and animals and people that live in the desert need to be built or adapt in some way to survive these extreme temperatures.

The hottest time of year is a few days before the summer Solstice on June 21, and a few weeks after that. Then the average daily temperature starts going down again, very very gradually.

A few weeks after the solstice is also the time when the summer monsoons really get going. The standard definition of monsoon season is the change in the wind, but in the desert, the important thing is that the monsoon usually brings moisture and finally rain from the Gulf of California and the Gulf of Mexico.

And of course, when the humidity goes up and the rains start, it’s still over 100 degrees in the desert. And it’s no longer a dry heat.

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Plant vegetables NOW?

February 15, 2011

Now that we’ve had another hard freeze in the Sonoran desert that burned the tops off many shrubs, and melted tomato and pepper plants down to the ground, February may finally be time to plant again. But have your frost covers ready, just in case.

Tomato and pepper seedlings need to be transplanted now to give them a chance to ripen before the summer heat bakes them.

And all kinds of salad greens and onions can be planted as seeds or seedlings for a good crop. If you plant seedlings of lettuce, beets and chard, they will begin producing salads within a week or two, and continue into early summer.

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What are Desert Wetlands?

July 15, 2010

The definition of desert is a dry place. So what do you mean, desert wetlands? Like most things in nature, deserts are more complicated, and interesting, that you’d think at first.

For example, there are many kinds of wetlands found in or near deserts:
Ponds
Freshwater and Salt or Alkaline lakes, like the Great Salt Lake
Springs and Seeps
Creeks, Streams and Rivers
Intermittent Streams, like the Hassayampa River
Disappearing Streams, like the Hassayampa River
Canals, Impoundments and other built wetlands
Oceans

Because they are such a distinct change or edge, they often host a surprising variety to wildlife, including disjunct species, that is, organisms typically found in distant areas.

This also means that they are often good places to view wildlife.