Rain forests and even Canada’s far north are home to cacti. However, their most amazing characteristic is their capacity to flourish in the desert, where rain occurs sporadically and erratically.
By working evenings, finding alternate ways to get energy, and maintaining a bag of sour tricks.
The cactus have developed a wide range of adaptations to live in the desert, according to Erika Edwards, a plant evolutionary researcher.
The saguaro, or Carnegiea gigantea, is one of the most recognizable cacti. However, they only flourish in the Sonoran Desert, where they can be seen growing tall in a small area of southern Arizona, northern Mexico, and southeastern California.
According to research by Edwards and Michael Donoghue of Yale University, leafy shrubs and trees of the Pereskia genus originally exhibited some of these water-saving characteristics over 20 million years ago.
The journal American Naturalist reported the findings in its June issue.
Stomata are tiny skin pores that open and close on all plants to capture carbon dioxide. Plants convert the carbon dioxide they have gathered into nourishment in the form of carbohydrates during photosynthesis. Water escapes from the pores every time they open, making the process challenging in the desert.
It’s hazardous business to open the pores and lose water if you’re attempting to conserve water, Edwards told LiveScience.
Cacti and other nocturnal plants, including agaves and aloes, open their pores at night while most plants open their stomata during the day.
Cacti are able to hold onto water because of the cooler temperatures, lack of sunlight, and quieter breezes.
In order to thrive in their harsh environments, cacti have also evolved succulent tissue, waxy skin, prickly spines, and a unique root system.
- The stem serves as a reservoir, and depending on how much water it contains, the plant will grow and shrink.
- The waxy layer of the skin keeps moisture in.
- The sharp spines defend against animals asking for a free sip out of thirst.
Some cacti have spines that also catch raindrops and deliver the valuable liquid to the plant’s roots.
You might imagine that cactus would develop extensive root systems to look for a steady source of groundwater. Instead, they frequently form large, shallow root systems that reach several feet away from the plant, sit just below the Earth’s surface, and are ready to collect as much water as possible.
Cacti grow additional roots when it rains. To conserve the plant’s water supply during dry times, roots will shrink and split off.
According to Edwards, “the cactus becomes more hydrated than the soil it is growing in.” It must cut its connection to the soil since it faces the risk of losing water to the soil.
Even lacking the morphological peculiarities of the typical leafless cacti, leafy cacti like the Pereskia and other plants have evolved comparable water-saving features and reside in the desert.
It’s solid proof that the tactic is effective, according to Edwards. “The plants thrive very well in these conditions.”
How Are Cactus Adapted To Survive In A Desert?
Cacti have unique adaptations in their stems, leaves, and roots that allow them to survive in desert conditions. Among these modifications are:
- In order to minimize water loss through transpiration, leaves are reduced to spines.
- Wide and deep roots can collect surface rains and access deep subsurface water.
- To prevent water loss, stomata are recessed.
- Stems with a waxy coating help to retain water and are fleshy and thick to store water and carry out photosynthesis.
Cacti only flourish in deserts, right?
There are about 1700 species of cactus, the majority of which are indigenous to the Americas. Different conditions support the growth of various species. Here are a few of the climate zones where cactus can be found.
The Desert
Some cacti can be found in regions prone to drought, including Mexico, Texas, sections of South America, the southwest of the United States, and the Atacama Desert in Chile, the driest spot on Earth.
Deserts are where the majority of cacti species thrive. Their ability to adapt to their surroundings is what allows them to live. They make the most of the rain by storing as much water as they can. Since their roots are on the surface, they can swiftly gather water and store it in their stems.
Approximately 90% of the water that the cactus stores is in the plant. For instance, when it rains heavily, the Saguaro stores between 750 and 1000 gallons.
How does water not evaporate considering the hot nature of the desert?
Because their leaves have sunken holes and a waxy stem to prevent evaporation, cactus may continue photosynthesis during the hot season unlike other plants that lose their leaves.
In order to release some moisture, the pores frequently open at night and seal throughout the day.
They are shielded by their spines from predatory creatures. However, animals with papillae, like camels, can consume cactus with little discomfort because the spines don’t stop them from doing so.
Prickly pears, barrel cacti, and cholla are a few of the prominent species that can be found in desert regions like California.
Rainforests
Some species of cactus can be found in tropical rainforests in places like central America, the Caribbean Islands, northern South America, southeastern Brazil, and Bolivia.
Contrary to popular belief, cacti can be found in areas other than deserts. There are several that are known as jungle cactus and grow in tropical jungles. Jungle cacti lack spines, in contrast to their predominantly thorny desert counterparts.
The majority of cacti are found in cloud forests at elevations of 1,000 to 2,000 meters.
The Thanksgiving, Easter, and Christmas cacti are among the well-liked species. Most of these cacti are epiphytic or lithophytic (grow on rocks) (grow in trees). The air, dead leaves, or debris in crevices and crotches are where these succulents obtain the majority of their nutrients.
The cacti that grow inside of trees do so for support rather than to draw nutrients from the plants. Their elongated leaves’ main function is to absorb light.
It’s crucial to replicate soil that is similar to such natural conditions while attempting to cultivate jungle cacti. To do this, you’ll need a suitable potting mixture that includes, among other things, potting soil, pumice, oak leaf mold, and orchid bark.
Your cacti should always be repotted every two to three years, right after they have stopped blooming. Make that the cactus receive the proper quantity of light. They grow in limited sunshine, just like in the rainforests, so avoid exposing them to intense summer light.
Consider fertilizing them every two weeks with a tomato-type fertilizer once they reach the flowering stage. Make sure not to use a fertilizer with a lot of nitrogen.
Mountains
Cacti can be found in the highlands, despite how impossible it may seem. They do, however, flourish in low-latitude mountains. Whipple Mountains are home to such cactus.
As a result of ‘grabbing’ water in the air and facing the wind in this situation, the mountains will tend to break up the humid winds and have a side that rains.
Since the air that travels to the other side of the mountain returns compressed, hot, and dry, there is rarely any rain on that side of the mountain, which is known as the rain shadow. As they thrive in an arid climate, cacti frequently flourish in this mountainous region.
The fact that the soil in the highlands is typically degraded and extremely rocky is what allows cactus to thrive there as well.
The windy, rocky, and gritty soil found in mountainous areas is ideal for cacti growth.
Fishhook Barrel Cactus (Compass Barrel)
The core spines of the Fishhook barrel cactus are bent like a fishhook and have pronounced ribs. It is highly loaded with spines. They are lured to the sun, and because the dark side of the cactus grows more quickly, they tend to tilt south. They have a maximum height of 11 feet and a maximum diameter of 2 feet. The cup-shaped, day-blooming flowers range in color from orange to yellow to reddish.
The cactus is filled with a slimy alkaline fluid rather than water. The idea that the juicy interior of the barrel makes a wonderful water source is untrue.
Uses:
- The cactus was prepared for cooking over hot stones or serving as a storage container.
- To use as awls or needles for pricking tattoo designs, the spines might be put into firm pitch.
- A roasted, cloth-wrapped piece of the cactus with the spines removed was applied to painful areas.
Buckhorn Cholla and Teddy Bear Cholla (Jumping Cholla)
Different shrubby cacti with cylindrical stems made of segmented joints are referred to as cholla. These stems are actually modified branches that perform photosynthesis, water storage, and flower creation among other tasks.
The six-foot-tall buckhorn cholla is a green, shrubby, and tree-like cactus with elongated joints. Their spines are straw-colored, and their blossoms are yellow, orange, or red. Teddy bear chollas are shrubby, tree-like, light-green to bluish-green cacti that can reach heights of feet. Their spines are silvery, and their blossoms are greenish or yellowish.
- Its buds are rich in calcium, iron, protein, and fiber; an eight-ounce glass of milk has less calcium per serving than a four-ounce serving.
- A gel could be created and applied to the skin to soften it and treat burns. To heal burns or open sores, dried segment pieces were pulverized or burnt into a powder.
- To shield the plants from various animals, cholla trees were placed around gardens.
Hedgehog Cactus
With green, cylindrical stems that can reach a diameter of three feet, hedgehog cacti grow in broad, globular clusters. Their cup-shaped flowers have a green stigma in the middle and come in a variety of pink hues. Their spines are yellowish in hue. Their little fruit can be eaten and is reputed to have a strawberry flavor. It contains a lot of sugar and fat.
- Sunburns, cuts, abrasions, compound fractures, open blisters, and insect stings were all treated using the inner flesh.
Pincushion Cactus
This little, cylindrical cactus only gets as tall as 6 inches. Its top is covered in 1/2-inch long hooked spines, while the body is encircled by numerous straight spines. Their spines are dense and grey, and their blossoms range in hue from pink to lavender. A tiny, scarlet fruit follows the flowers.
- Rub the tiny red berries on arrow shafts to give them color.
- The cactus is cut, boiled, and inserted warmly into the ear to relieve ear pain once the thorns have been removed.
Englemann’s Prickly Pear Cactus
Flat, fleshy pads of prickly pear cacti resemble huge leaves and are covered in spines. These pads, which are really modified branches, have various purposes, including flower formation, water storage, and photosynthesis. They are a wide-spreading cactus with a maximum height of 5 feet. Their fruit, known as tunas, is red to purple in color and follows their yellow, orange, or reddish flowers. The pads and fruit are both eatable and available in supermarkets right now.
- Ripe fruits can be consumed in a variety of ways, including fresh, dried, powdered, combined with cornmeal, fermented for a drink, or prepared into syrup.
- The young pads can be cleaned, sliced, and consumed raw or cooked after being dethorned. Their flavor is comparable to green beans.
- The pad could be applied in a number of ways, including as an insect repellent or as an anti-inflammatory for gastrointestinal and urinary tract infections, as well as to treat wounds, burns, sunburns, insect and scorpion stings, the mumps, rheumatism, bruises, bleeding, inflammation, and toothaches. They might be successful in treating cancer, lowering cholesterol, and lowering blood sugar.
- The sticky sap can be used to create candles, chewing gum, and as a cotton stiffener. To strengthen whitewash or adobe mortar, combine it with lime, sand, and water.
- The flowers’ extract helps hasten recovery and lessen inflammation.
- Drinking water is clarified using the pulp. Cut several pads into thin strips, combine them with four parts water, and let the mixture sit for a few hours.
Saguaro (Giant Cactus)
One of the flora that characterize the Sonoran Desert is the saguaro cactus. The largest cactus in the US, they grow into tall, tree-like structures with branches or arms as they mature. They have white blooms in the late spring, protecting spines all over, and red fruit in the summer. Study up on the saguaro cactus.
- Fresh, dried, fermented into wine, or converted into jelly or syrup, the fruit is delicious. A single serving, or around five fruits, has a lot of fiber and vitamin C and provides 167 calories, 4 grams of protein, and 5 grams of fat.
- The tiny seeds can be used to make flour or a spread that resembles peanut butter. Lard is swapped out for the oil.
- The wood is employed for canes for dancers, the elderly, and the blind, as well as for constructing, splinting, and lighting fires.
- Rheumatism is treated by wrapping a hot piece of flesh in cloth.
- Food and other items are carried in and stored in saguaro boots.
How do cacti develop?
Birds, wind, and rain all disperse cactus seed. A cactus plant can produce a million seeds over the course of its lifetime, but only one or two of those seeds will germinate into a new cactus. Some cacti reproduce asexually, without seeds or flowers, while others reproduce sexually.
How do plants thrive in arid environments?
Students will comprehend that qualities are inherited from parent organisms to their offspring and that offspring may exhibit variations of these features that may benefit or hinder survival in a particular environment. This is covered in Utah Science Core Curriculum Topic, Standard Five.
Comparing desert plant adaptations, riparian plant adaptations, and a few desert plants and animals adapted to nighttime activities allows students to learn about genetics. A story, a smelling game, a clue trail, plant keys, and rough observation and data collection are some of their field activities. In class exercises, students pretend to be a desert animal or plant and then design a fictional plant that has adaptations for surviving in the hypothetical habitat.
Objective(s)
a. Describe two riparian zone environmental features that are distinct from the desert’s surroundings.
b. Describe the interaction between a yucca moth and an evening-blooming yucca.
a. Describe three adaptations a plant might have to survive in a riparian or desert setting.
Overview
Desert plants have developed a variety of adaptations to cope with their dry habitat. Plant leaves have stomata, which are holes used for water transpiration. Many desert plants have fewer and smaller stomata than other plants do. Many cacti have stomata that are buried deep within their tissues. By preventing the hot, dry wind from directly hitting the stomata, this adaptation helps cactus conserve water.
Many desert plants have a thick, waxy covering on their leaves and stems. The majority of the leaves are covered by this waxy substance, which keeps the plants cooler and lowers evaporation loss but does not cover the stomata. Desert plants with small leaves also contribute to a reduction in transpirational moisture loss. Small leaves mean less evaporative surface per leaf. Furthermore, the temperature of a little leaf in the sun is lower than that of a large leaf in the sun.
Some plants, including cactus and Mormon tea, perform most or all of their photosynthesis in the stems of their green leaves. (In a botanical sense, the pads of cacti are stems.) During the wet season, some desert plants produce leaves, which they later drop when the weather gets dry once more. During wet times, several plants, especially blackbrush, photosynthesize in their leaves. Some of these plants can photosynthesize in their stems when drought strikes and the leaves fall off. Others reduce water loss even further by briefly stopping photosynthesis.
Other desert adaptations include spines or hairs to shade plants and break up sunlight, short, widely spaced roots to receive as much moisture from rainfall as possible, etc.
the following particular adaptations of desert plants:
Cacti – The modified stems that make up cactus pads have a waxy coating. Their roots are relatively shallow and only absorb fleeting moisture. As soon as rain moistens the soil, little rain roots can start to form. Later, they disappear. Prickly spines are modified leaves that can assist shade the stem and disperse evaporative winds blowing across pad surfaces. The stomata of cacti only open at night, when the plant is relatively chilly, allowing for less moisture loss through transpiration. Additionally, gases such as carbon dioxide entering the plant and oxygen leaving the plant flow through the stomata. This gas exchange takes place as part of the photosynthetic process. But sunlight is also necessary for photosynthesis. A method of chemically storing the carbon dioxide until the sun is out, when it may be used to complete the photosynthetic process, is part of the CAM process. (A stoma is like a window; it must be open for air and water to enter or exit, but sunlight can still enter even when it is closed.)
Desert annuals – By persisting as long-lived seeds deposited in the soil, often for decades, these plants survive drought and heat. The seeds have characteristics that ensure their growth and germination during moist conditions.
Globemallow – These reflect sunlight thanks to its abundant, star-shaped, grey hairs.
Juniper – The twigs and little branches are covered in thin, waxy scales in place of leaves. Waxy coatings are also present on fruits. During a drought, junipers have the capacity to cut off water to a large branch, leaving the tree alive but with a dead branch.
They are just somewhat parasitic, paintbrushes. To obtain food and moisture from their host, their roots pierce the roots of adjacent plants, typically sagebrush or grasses.
Pion pines rely on extensive root systems. In deep soils, pion taproots can extend 40 feet or more; in shallow soils, lateral roots can extend the same distance.
The plant known as sagebrush protects itself from heat, cold, and dry winds with its hairy leaves. The plant can provide food throughout the majority of the year since it keeps its leaves all year. Its leaves point in all directions, allowing them to catch sunlight from a variety of angles, and sagebrush can photosynthesize when temperatures are close to freezing. Sagebrush has evolved to withstand severe winters.
Some desert plants utilize the cooler nighttime temperatures to develop “active. Evening primrose, sacred datura, sand verbena, and yucca are some examples of night-blooming desert plants. Cacti benefit from milder nights as well. Stomata on cacti are typically open at night. As a result, the plant can transpire, or lose water, when it is likely to do so in the smallest amount. The remaining stages of cacti’s photosynthesis occur during the day.
Desert animals also benefit from the cool haven of the night. Desert animals rely on their other senses to guide them because they lack light for visual signals. Bats that consume nectar utilize echolocation to recognize plants that bloom at night. Similar to radar, echolocation involves the bat making a call and then picking up waves that are reflected back at it. The direction and size of the reflecting object are revealed by the reflection.
The relationship between the yucca and the yucca moth is remarkable at night. After mating, the female moth collects pollen from a single yucca blossom, rolls it up, and then flies into the night, mostly by using “She used her antenna to smell. Each time she visits a new flower, she deposits a few eggs at the base of the pistil and stuffs the pistil with pollen for her young to eat. She fertilizes the yucca blooms as a result. Only yucca moths can pollinate yucca blooms, and the young of these moths can only eat yucca pollen.