Archive for the ‘Water’ Category

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Ocotillos in bloom

April 11, 2011

It is mid-April and the ocotillos are in bloom in the Sonoran desert, a great sight to see.

These plants can leaf out several times a year after rains, but they only bloom once a year, the blossoms providing food for a variety of insects and birds.

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Snow in the desert

December 31, 2010

Snow showers in the Sonoran desert, 30 December, 2010, after two days of rain. Rare treats.

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Autumn desert vegetable garden

October 8, 2010

Into October now, it is already getting late, but perhaps a reminder for next year–fall is the other good time to start a food garden in the desert.

You will probably not have much success with foods that need to flower and fruit, but for leafy greens, this is a great time.

Chard, spinach, beet greens, herbs, all these can still be planted in the desert in October. Of course, they will need hand watering or irrigation. But some will produce right through the winter, depending on your location.

Some will go dormant, then revive in late January and February, when the longer daylight and warmer temperatures begin to return, the time when you can begin adding your regular spring vegetables.

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Limiting factors in the desert

September 16, 2010

In some ways the term “limiting factor” is almost a definition of deserts, because deserts lack one or more essential ingredients for the survival of most kinds of plants and animals.

First, a desert is, by definition, a place with very little available water, either because there is little rainfall, or because it evaporates so fast. It may also be that most of the precipitation is unavailable because it is frozen most of the year, as in the far north or south, or in some high altitude regions.

Some areas may get bursts of moisture, even flooding, but it is episodic and not dependably available most of the year.

Temperature is another limiting factor. Many deserts get too hot for most organisms. Some deserts near the north and south poles are too cold. And yet others have wide swings in temperature.

Wind is another. There are few trees or shrubs to stop the wind. Desert mountains, river-courses or other sheltered areas may harbor small oases in their wind and sun shadows.

One unusual limiting factor is lack of sunlight. This can occur in deserts near the poles.

Especially interesting are the adaptations that plants and animals have developed to deal with these limiting factors. Many of them are what we talk about here.

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Leafing again: the strange case of the ocotillo

August 6, 2010

One of the odder native residents of the Sonoran desert is the ocotillo bush. It typically consists of several spindly branches, vertically striped and spiny, up to 20 feet tall, that are leafless for long periods, only to sprout thick lines of small leaves within a few days after a rain.

Ocotillo branches with few leaves

Ocotillo branches with few leaves

Its desert adaptation of dropping leaves and playing possum is so complete that ocotillo plants for sale, in their leafless phase, with their branches tied in a bundle and roots bare, look thoroughly dead.

Ocotillo branches with many leaves

Ocotillo branches with many leaves


In the spring, they produce numerous red tubular blossoms at the ends of the branches that attract insects and birds of many species. They make great landscape plants because of their sparse sculptural look, and extremely low water requirements, and striking seasonal changes.

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On little coot feet

July 21, 2010

The American coot looks like a little round black duck. With a white snoot. And mad red eyes.

But it is not, not a duck.

After you look for a while, it also looks like a young chicken, a pullet, with a football shape, but rounder than a football.

A chicken, getting warmer.

Coots are in fact related to chickens, and more closely, to mudhens. (Go Toledo!)

While we think of them as northern wetland animals,  you can actually find them in the Sonoran desert, on some of the occasional lakes in the desert. They swim around, most often in pairs, and dive to gather vegetation, and the, um, scum from the bottom that they eat.

But the most amazing thing about coots is their feet. They have very strange feet. Not just plain chicken feet. But not duck feet, webbed paddling feet either.

They have these strange little flaps on the sides of their toes, very clever flaps actually, that make their toes very wide when they step down, or when they push against the water, but fold up to slender claw-width when they lift their feet, or bring them forward in the water, or take off in flight.

They are not easy to spot– you have to be quite close, or have the coots pose just right, then you can see them.

So if you see a round black swimming chicken-duck-bird with a white bill-beak and crazy red eyes, make sure you look for their really crazy black and gray flapped coot feet.

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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.

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A thorny issue

June 23, 2010

Related to the last post, it is amazing how many kinds of thorns, bristles, hooks, spikes, prickers, sharp edges, pointed leaves, pointed branches, as well as claws, scales, fangs, spines, and hooves you find in the Sonoran desert, and generally in the arid western USA.

In a contrary kind of way, almost all of these indicate that there’s probably a nice, juicy, succulent hunk of flesh nearby.

But you’ll get hurt if you try to get at it!

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Why does the cactus look like that?

June 16, 2010

The first thing you notice about a cactus is generally the spines. Some have short, nasty little almost invisible fishhooks, some inches-long needles. Then there’s the form of the plant. Most cacti are plump, rounded, often stubby. They tend to be grayish-green in color. And they usually do not have obvious leaves.

Why?

Whenever you come across questions like this, think about the ecosystem where the organism lives. Cacti live in dry climates with a lot of sun, and few other plants, especially leafy ones.

So keeping cool is an issue. A light neutral color does not absorb a huge amount of the sun’s heat. There are very few plants with dark bark, or skins, or leaves in the desert.

Retaining moisture is perhaps the most important issue for a desert plant. The blunt, compact shape of cacti, their thick skins, and lack of leaves are all moisture-conserving features.

And lastly, toothsome, moist leaves would attract all kinds of herbivores. So the lack of leaves discourages plant-eaters, and the big spines and tough hide protect any soft, moist tissue a cactus does have.

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Plant your own desert landscape

June 30, 2008

There are obvious as well as more subtle things to consider when planting a landscape around your desert home.

Not surprisingly, the number one limiting factor in the desert is water.

Domesticated cactus

Domesticated cactus

The number two limiting factor is shade. Some desert plants can’t tolerate any, some need it.

Other factors such as temperature, predators, and wind vary by specific location.

Interestingly enough, as well as enduring brutal heat, many parts of the North American desert reach temperatures below freezing at least a few days a year. The thorns and armor on many desert plants attest to their predators, ranging from insects to grazing mammals.

See what the experts have to say about useful and well-adapted plants that conserve resources:  www.amwua.org:plants_index.html

With a little knowledge, you can enhance your landscape naturally.