Plant adaptations

Did you know that not all deserts are hot? Some deserts are extremely cold and they are called tundra deserts. Here is a video that shows how plants in different conditions adapt to the environment. Enjoy :)

More about plant adaptations in deserts

Desert Plant Adaptations
Habitats in Central Washington range from alpine and rainforest in the west, to dry ponderosa forests and shrub steppe to the east. A few plants can live in variety of conditions, and some are restricted to specific habitats.
The plants that grow in the arid eastern region near the Columbia River and the Columbia Basin have a number of traits which help them to be successful in the desert. In the photo to the left is Salvia dorrii and Artemisia tridentata in the Columbia Basin near Moses Coulee, Washington State. Two of the main adaptations of plants in arid environments is having an economical water management system, and maximizing the energy gain from the process of photosynthesis. Some plants, called xerophytes, have adapted their physical structure to suit the rigors such a harsh environment as the desert. 1/3 of the earth's land surface is desert, or about 10% of the total earth surface. Xero- means dry and -phyte means plant. These plants have adapted by having smaller leaves, grow compactly and close to the ground, and a non-porous covering on their leaves such as wax. Hair on the leaves of plants helps to reduce the evaporation of moisture from the surface of leaves by reflecting sunlight and inhibiting air movement. The process of photosynthesis requires both carbon dioxide and water to create energy for the plant. Water is usually absorbed through the roots, and carbon dioxide is absorbed through tiny pores in the plant called stomata. Through the stomata the plant is able to obtain carbon dioxide, but it also loses water by evaporation when the pores are open. Some plants cope with the water loss problem by having fewer stomata, or by having the stomata only open at night when it is cooler. All of these adaptations help to reduce evaporation and transpiration of water. Differences in cellular structure and function, as well as in the basic process of creating carbohydrates from water and carbon dioxide also help plants to survive in arid conditions. The common process of photosynthesis is called the C3 cycle because carbon is fixed by the plant into a three carbon compound (phosphoglyceric acid) in order to make carbohydrates. Another process of photosynthesis used by desert plants such as bunchgrass fixes the carbon into a four carbon compound (malate or aspartate acid). This C4 process, although not used by many plants, is more efficient in maximizing energy gain than normal photosynthesis.

Pseudoroegneria spicata- bluebunch wheatgrass.
Succulent plants such as stonecrop (Sedum spp.) and cactus can store water in the specialized tissues of plant cells called vacuoles. In some desert plants the cells, unlike in the ordinary varieties of cultivated plants, can also survive extreme dehydration then rehydrate when water is available with little or no damage to the cells. It also helps desert plants to have spines or prickles to deter animals from eating the photosynthetic material it worked so hard to produce. Succulents especially need this protection because their cells are full of water that thirsty animals would love to eat. There also many chemicals that are produced by plants that deter herbivores. Other plants, called phreatophytes, have adapted root systems that are long enough to reach underground water sources. Phreato- means well and -phyte is plants. Tamarisk or salt-cedar is example of a phreatophyte. It is an invasive non-native plant, which can cause severe problems because it robs rivers and aquifers of water particularly in the Southwest US. Native examples of phreatophytes an extensive root system is the big sagebrush (Artemisia tridentata) and Ericamerica nauseosa, whose roots can grow up to 25 meters deep. Because big sagebrush is able to utilize underground water sources it can remain photosynthetic throughout the summer, and is one of the latest blooming of all plants in the Columbia Basin. Other plants cope with the extremes in temperature and rainfall by becoming dormant during the winter or droughts, and escaping difficult times all together. Annual plants, also called ephemerals, only grow for one growing season- from seed to flower to seed and grow only when conditions are at optimum. Some seeds can remain dormant for years and even decades, waiting to germinate when the conditions are favorable. Members of the Liliaceae- Lily family and others such as the genus Lomatium (Apiaceae family), store energy within their roots when they bloom in spring and set seed. The Lomatium macrocarpum or bigseed biscuitroot has 80% or more of the plants tissues are below the soil surface in the roots. This stored energy is enough to survive for most of the year in a dormant state. By late summer the upper parts of the plant and leaves dry out above the ground and the have already matured and blown away, leaving none of the plant's soft tissues exposed to heat and dryness of summer. By the middle of summer many plants in a desert environment are dormant, and show few signs of life. Another strategy of drought avoidance can be seen near any stream or wet area. Some plants only germinate and grow in riparian areas, forming the stark contrast in vegetation seen near any water source in arid regions.

Source: http://www.cwnp.org/adaptations.html

Adaptation to dry conditions

This is a plant which is able to survive in very dry conditions. Its sahpe is very different from that of plants found in wet places. Therefore, it is said to be adapted to suit its environment. Environment means surroundings. Adapt means to change so as to fit in with the surroundings.

Plants which are able to survive in dry conditions are called xerophytic. These usually undergo four main types of adaptation, all of them to help conserve water. Conserve means to use up as little as possible.
Take a look at the xerophytic plant. In this case, it is the famous cactus known for its spiky leaves. Did you know that the leaves are one of the most important adaptations of the cactus?

1. These leaves are thin, like spines, and curled round so that water losing pores (stomata) are on the inside, away from the sun and wind.
2. The roots spread out just under the surface of the soil. This is so that when the rain falls, it rarely soaks more than one metre deep. The roots spread out widely in this shallow layer to take in soil water quickly after a shower
3. Desert plants store water to conserve water. Roots and stems are some parts of the desert plants which are able to do so. A round shape can hold more than a long, thin shape so most desert stems have riunded, swollen shapes
4. Stems and leaves are designed to reduce water loss by evaporation. They have a waxy coating which keeps water in . The rounded shapes give desert plants snall surface area for their size compared with plants in wet areas. This means thet have less surface to lose water from, so they keep more water witthin them than plants in wetter lands.

Steps in science by R Bateman and P Lidstone Book 3

Chapter 2 page 14

Autotroph Humans

Here is the article Mrs Phua showed us in class. Enjoy! :) It is not ruled out that they will replace us at a new evolution stage People all around the world were storming supermarkets and grocery stores on Christmas and New Year's Eve. There was a small group of people, though, who did not even think about eating anything for Christmas. In fact, they do not think about food at all. Such people call themselves autothrophs – they do not eat at all. The term designates an organism that makes its own food. Autotrophs can go on hunger strikes for years and even decades. Irina Novozhilova, the president of the center for protection of animals' rights, expressed her opinion about phenomenal individuals, who can live without food and water. ”The idea to turn down food as it is appeared long ago. Russian philosophers, particularly Vernadsky, were thinking about a possibility for a human being to live on something non-material. Vernadsky was certain that man is an energetic creature that can nourish himself from the energy of space. Some people can prove it today that it is possible to live a normal life without physical food. ”All living beings on our planet can be divided into two categories – autotrophs and heterotrophs. The majority of plants constitute the first category – they receive energy from non-organic substances – sunshine or air – and process it during the photosynthesis. Humans and animals make the second category: they nourish themselves with other living beings. Therefore, the people, who can live on the solar and space power, are closer to plants than to other humans. There is a group of autotrophs in Moscow. They gather in the Konstantin Vasiliev Museum, where they share experience with others. If a woman breastfeeds her child until it turns seven years old, for example, a child will be able to become an autotroph already by eight – simply and painlessly. A mother neither drinks nor eats, but she has enough milk to feed the baby. There are such women in Moscow. I often interact with people, who reject food completely. At first they become vegans - they exclude all products of animalistic origin from their menu in other words. After that they gradually turn down the vegetal food too. When people stop eating physical food, they also stop consuming any kind of liquid. They drink nothing. ”I would not say that scanty nourishment exerts a negative influence on their state of health. They are rather vigorous and cheerful people. However, I would like to warn everyone that it is impossible to quit drinking water and eating food in a moment. It should be done slowly, step by step, with short-term temporary starvation. A lethal outcome would be inevitable otherwise. A person will be killed either with starvation or their own wastes. The 70-year-old Indian yogi Pralad Djani is one of the most renowned contemporary autotrophs. This man has not been eating or drinking anything for 62 years, since the age of six. Indian doctors examined and tested him: they placed the man in a special room, outfitted the room with surveillance cameras and sealed the bathroom. As it turned out, Pralad Djani's body was functioning absolutely normally. The body was producing urine, although it was being absorbed into the urinary bladder. The yogi said that he was receiving water from air. He also said that there was a tiny hole in the palate, from which drops of “heavenly” water penetrated into his mouth. ”Russia's most famous autotroph's name is Zinaida Baranova. The old lady from the city of Krasnodar is 67 years old. She was approaching her new existence very slowly. At first she gave up meat, then she turned vegetables down. She has been living without food and water for 4.5 years already. Scientists of the Bauman Institute examined her organism and were very surprised to find out that the woman's biological age corresponded to 20 years. Professor Spiridonov came to conclusion that the pensioner was a perfectly healthy lady; all her systems and organs, except for the stomach, were functioning normally. Indeed, she is a very energetic and bubbly person. She got rid of all diseases, even chronic ones. She said, however, that it was rather hard for her to get used to the new lifestyle. She was suffering from cramps, exhaustion, dry mouth, etc. There were moments, when she thought she was dying. The woman's health improved in 1.5 months. ”Doctors say that autotrophs make a fundamentally new type of self-sufficient human beings. It is not ruled out that they will replace us at a new evolution stage. Modern science has already confirmed the ability of a human being to maintain itself. Dietitians were recently saying that the B12 vitamin was naturally contained only in animal foods. Vegans, therefore, were supposed to die, since they could not receive the vitamin. However, doctors found out that the concentration of the B12 vitamin was fine with vegans. The situation became clear, when scientists discovered the synthesis process in the intestines. It became known that human beings could live on their own microflora. Medics have already discovered that the human intestines produce microorganisms that can synthesize amino acids.” http://english.pravda.ru/science/19/94/377/14815_autotroph.html

Cactus Juice

Health Benefits of Cacti

There is more to the cactus plant than just a prickly house ornament to collect and admire. Medical studies conducted reveal that cactus extract contains phytochemicals, the cancer-fighting nutrient found in most fruits and vegetables, and also nutrients that strengthen the immune system.

Cactuses are drought-resistant plants found mostly in hot and dry regions. Cactus fruits are considered by some as “nature’s most perfect food”, with a large percentage of water, sugar, and minerals contained in it’s soft and gel-like flesh. The fruit performs a laxative function, increasing the frequency and ease of bowel movements. The gel extract is also used in some parts of the world as a remedy for non-insulin dependent diabetics. An experiment conducted on non-insulin dependent patients showed a significant decrease in blood glucose and insulin levels in patients who were given a cactus-water solution. Cactus extract is also a food source of phytochemicals. It enhances and strengthens the immune system’s ability to resist infection.

Another experiment conducted on the wound-healing properties of cactus juice produced a positive effect. Clinical studies show that the opuntia cactus is effective in fighting chronic inflammation. Cactus juice prevents scar forming and inflamation of the wounded area. The results of the experiment also show that cactus improves circulation and wound healing substantially.

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Nopal cactus juice is made from this desert plant's brightly colored fruit. You can use prickly pear cactus fruit for inflammation found in many areas of the body.

• Muscle
• Gastrointestinal
• Cardiovascular
• Arterial
• Bone

The fruit of the Nopalea cactus contains high amounts of calcium, magnesium and vitamin C. This cactus fruit also contains the amino acid known as taurine, is rich in flavonoids and antioxidant proteins known as betalains.

Nopal cactus fruit is low in calories, as well as sodium. In addition, it does not contain any cholesterol or saturated fat.

Nopalea cactus fruit nectar is also high in soluble fiber. The kind that is effective in reducing cholesterol in the blood. The American Heart Association has conducted research to measure nopal cactus fruit's ability to control cholesterol levels.

Nopal Cactus Juice Health Benefits

The nopalea cactus can provide you with the following health benefits:

• Helps you to lose weight! It curbs your appetite and blocks your body's ability to absorb fat
• Lowers your blood pressure
• Lowers your cholesterol levels! It improves your HDL / LDL ratio
• Helps to cleanse your body of harmful toxins
• Lowers your blood sugar levels
• Improves your mental focus & clarity

Find out more on http://www.best-natural-health-supplements.com/nopalea.html

Sources:http://worldvillage.com/health-benefits-of-cacti

http://www.best-natural-health-supplements.com/nopalea.html

How do desert plants adapt to conditions in the desert?

How Plants Cope with the Desert Climate

*Highlighted points are the adaptations

Desert plants have developed three main adaptive strategies: succulence, drought tolerance and drought avoidance. Each of these is a different but effective suite of adaptations for prospering under conditions that would kill plants from other regions.

Succulence - What adaptations do they have to survive in the desert?

Succulent plants store water in fleshy leaves, stems or roots. All cacti are succulents, as are such non-cactus desert dwellers as agave, aloe, elephant trees, and many euphorbias. Several other adaptations are essential for the water storing habit to be effective.

A succulent must be able to absorb large quantities of water in short periods.Desert rains are often light and brief, and the soil dries rapidly under an intense sun. To cope with these conditions, nearly all succulents have extensive, shallow root systems. The roots of a saguaro extend horizontally about as far as the plant is tall but are rarely more than four inches (10 cm) deep. The water-absorbing roots are mostly within the upper half inch (1.3 cm).

Succulents must be able to maintain their water hoards in a desiccating environment and use it as efficiently as possible. The stems and leaves of most species have waxy cuticles that render them nearly waterproof when the stomates are closed. Water is further conserved by reduced surface areas; most succulents have few leaves (agaves), no leaves (most cacti), or leaves that a deciduous in dry seasons (elephant trees, ocotillos, boojums).

Many succulents, as well as semisucculents such as most yuccas, epiphytic orchids, and xerophytic bromeliads, possess a water-efficient variant of photosynthesis called CAM, an acronym for Crassulacean Acid Metabolism. CAM plants open their stomates for gas exchange at night and store carbon dioxide. By day, while the stomates are closed, photosynthesis is conducted using the stored carbon dioxide. Because of the lower temperatures and higher humidity at night, CAM plants lose one-tenth as much water per unit of carbohydrate synthesized as standard C3 plants.

Another valuable attribute of CAM plants is their capability for idling metabolism during droughts. When CAM plants become water-stressed, the stomates remain closed both day and night; gas exchange and water loss nearly cease. The plant, however, maintains a low level of metabolism in the still-moist tissues. Just as an idling engine can rev up to full speed more quickly than a cold one, an idling CAM plant can resume full growth in 24 to 48 hours after a rain. Therefore, succulents can take rapid advantage of ephemeral surface moisture.

Stored water in an arid environment requires protection from thirsty animals. Most succulent plants are spiny or toxic, often both. Some protect themselves by growing only in inaccessible locations. Still others rely on camouflage. Arizona night blooming cereus, for example, closely resembles the dry stems of the shrubs in which it grows.

Now we know why plants like the cactus that grow in the desert have swollen leaves and spiky leaves. It's all for a matter of survival!

Drought Tolerance
Drought tolerance (or drought dormancy) refers to a plant's ability to withstand desiccation without dying. Plants in this category often shed leaves during dry periods and enter a deep dormancy. Most water loss is from transpiration through leaf surfaces, so dropping leaves conserves water in the stems. Some plants that do not normally shed their leaves have resinous coatings that retard water loss (e.g., creosote bush).

The roots of drought tolerant shrubs and trees are extensive compared to those of plants in wetter climates, covering an area up to twice the diameter of the canopy. They exploit the soil at greater depth than the roots of succulents; sometimes they extend to extreme depths (e.g., mesquite). Most of a mesquite's roots, however, are within three feet (0.9 m) of the surface.

(I think these type of plants do have roots that are so deep in the ground to absorb more water)

Rooting depth controls opportunities for growth cycles. In contrast to the succulents' shallow-rooted strategy, a substantial rain is required to wet the deeper root zone of shrubs and trees. After a soaking rain has fallen, shrubs such as brittlebush and creosote take a few weeks to resume full growth from deep dormancy. The tradeoff between this strategy and that of succulents is that once the deeper soil is wetted by several rains it stays moist much longer than the surface layer, supporting several weeks of growth.

Succulents can absorb water only when the soil is nearly saturated. In contrast drought tolerant plants can absorb water from soil that is much drier. Similarly these plants can photosynthesize with low leaf moisture contents that would prove fatal to most plants.

Drought Avoidance
Annual plants escape unfavorable conditions by not existing. They mature in a single season, then die after channeling all of their life energy into producing seeds instead of reserving some for continued survival.

Most Sonoran Desert annuals will germinate only during a narrow window in the fall, after summer heat has waned and before winter cold arrives. During this window of opportunity there must be a soaking rain of at least one inch for most species. This combination of requirements is survival insurance: an inch of rain in the mild weather of fall will provide enough soil moisture that the germinating seeds will probably mature and produce seeds even if almost no more rain falls in that season. There is still further insurance: even under the best conditions not all of the seeds will germinate; some remain dormant. Although the mechanisms are not known, a percentage of any year's crop of desert lupine seeds will not germinate until they are ten years old.

Seedlings rapidly produce rosettes of leaves during the mild fall weather, remain flat against the ground as they grow more slowly through the winter, and bolt into flower in the spring. Since the plants are inconspicuous until they begin the spring bolt, many people mistakenly think that spring rains produce our wildflower displays.

Annuals are common only in communities that have dry seasons, where the spacing of perennial plants is determined by the rooting space required to obtain enough moisture to survive the driest years. In the occasional wetter years both open space and moisture are available to be exploited by a population of fast-growing annuals. The more arid the habitat, the greater the proportion of annual species. Half of the Sonoran Desert's flora is comprised of annual species. In the driest habitats up to 90% of the plants are annuals.

The desert environment may seem hostile, but this is purely an outsider's viewpoint. Adaptations enable indigenous plants and animals not merely to survive here, but to thrive most of the time.

Source: http://www.desertmuseum.org/programs/succulents_adaptation.php

An interesting video on sound