Desert plants thrive on dry, sandy soil with plenty of direct sunlight. To cope, these species have evolved special adaptations such as thick cuticles, reduced leaf area, sunken stomata and hairs.
A thick cuticle helps conserve water through leaves, especially in dry climates such as deserts or Mediterranean regions with limited rainfall. Furthermore, it protects plants from pathogens, dehydration, and UV radiation.
Land plants typically have a cuticle, or waxy layer, that prevents water loss through evaporation. This is essential for many reasons such as keeping out pathogens and shielding the plant from UV radiation damage caused by intense sunlight.
Desert biomes, where sunlight is intense and temperatures are high, often have developed special structures to conserve water. These may include thick cuticles, reduced leaf areas, sunken stomata or hairs that reduce transpiration.
Desert plants have evolved to conserve more water than their nearby peers, enabling them to flourish and grow. Cacti, for instance, have spines which reduce transpiration and shield them from UV rays. Furthermore, their leaves possess specialized structures which reduce stomata (pores) on their leaves–porous openings which regulate water and gas exchange–to regulate their transpiration rates.
The thickness of a plant’s cuticle can inhibit photosynthesis by slowing the entry of light and carbon dioxide into its leaves, thus decreasing its capacity to burn calories. Thus, thicker cuticles result in slower calorie burning rates as well as slower growth overall.
Some plants, like yucca filamentosa (Adam’s needle), possess thick cuticles which enable them to survive in dry climates. Yucca also features stomata that open and close periodically during nighttime to regulate water and gas transfer; when nightfall arrives, these pores open to receive oxygen and water for photosynthesis while closing them at daybreak to reduce transpirational loss of water.
Cuticles are not only important barriers against evaporation, but they can also add strength to a plant’s lamina. Specifically, cuticle layers increase the outer periclinal walls’ durability – an advantage when faced with bending stresses.
A thin cuticle can increase water permeability through the cell wall, but it is not as effective at preventing transpiration as a thicker cuticle that contains more waxes. This is because a thin cuticle may become weak due to cellular expansion while a thicker one retains its thickness and continuity even after this has stopped.
The cuticle is the waxy covering produced by epidermal cells of leaves, fruit and young stems. This protective layer reduces water loss from plants while shielding them from UV radiation, pollution, mechanical injuries and pathogen/pest attacks.
Many xerophytic plants, such as holly and prickly pear cactus, possess thick cuticles to prevent water loss through evaporation. Furthermore, these cuticles reduce transpiration and conserve water within the plant itself.
Thick cuticles are an adaptation that helps desert plants survive harsh environmental conditions such as heat, high winds, drought, erosion and dust.
A thick cuticle can aid in photosynthesis. This hydrophobic (water-resistant) barrier blocks light from entering and carbon dioxide from leaving.
Plants use this to maximize oxygen production, which is necessary for photosynthesis. It also helps control stomata–openings on leaves that allow gases to exchange between them and the atmosphere–by controlling how fast they open.
The cuticle is composed of a polymer matrix (cutin), polysaccharides and solvent-soluble lipids known as cuticular waxes. It covers plants’ leaves and stems on both inward-facing and outward-facing surfaces.
FTIR measurements were conducted to analyze the composition of natural cuticles before and after dewaxing and methanolysis. Results indicated that neither treatments significantly altered cuticle structure nor composition.
Additionally, FTIR data revealed that natural cuticles were thicker on the abaxial side of leaves than on the adaxial sides. This may have been due to older cuticles on the adaxial sides.
Therefore, it is likely that the old adaxial cuticles have a thicker natural cuticle than their new counterparts after dewaxing and methanolysis.
However, methanolysis could also alter the composition of the natural cuticle through chemical treatment, since some fatty acids were removed during dewaxing. These changes would likely result in a decrease of fatty acid concentration within the cuticle which could inhibit photosynthesis.
Desert plants must adapt and survive in an environment with limited water supplies, high temperatures, dry soils that are vulnerable to disease and erosion. To survive in such harsh conditions, desert plants must find ways to adapt.
Desert plants have evolved to survive by using smaller leaves and fewer stomata (individual pores that allow oxygen and carbon dioxide into the plant, as well as water vapor out). This reduces transpiration – that process which causes water loss from plants by allowing vapor out through their pores.
Another way desert plants conserve water is by decreasing their exposure to sun and wind. This helps them minimize water loss during photosynthesis, the process that creates food for a plant.
Desert plants often develop a thick, waxy layer on their leaves and stems that keeps them cool in the summer sun and prevents water loss due to evaporation. Additionally, this covering protects them from viruses, bacteria, and fungi.
Spines, hairs and spikes are other adaptations that many plants have to conserve water. These hairs and spines break up the drying winds that blow across leaves or stems, helping reduce evaporation rates due to increased airflow.
These plants’ spikes or spines provide protection from the sun and herbivores – animals that eat plants. Furthermore, these spikes or spines keep water in cacti and other desert plants by breaking up heat from solar rays.
Finally, some desert plants possess thorns which help deter animals from eating them. This is especially beneficial for cacti and other plants that need to store water or absorb it.
Desert plants can reduce water loss from transpiration by decreasing the amount of carbon dioxide they take in through their stomata. This is essential in order for them to take in enough carbon dioxide during photosynthesis.
Desert plants have evolved to survive in areas with little or no rainfall. To adapt and thrive in such an environment, they have evolved features like thick leaves, fleshy stems and long tap roots that store water underground for storage.
Plants possess stomata on the surface of their leaves that open and close to regulate water and gas exchange. Plants take in carbon dioxide while releasing oxygen and evaporated water back into the atmosphere – this process is known as transpiration.
Reduce transpiration through special shapes, sizes, surfaces and colors in leaves. Some plants even possess a waxy cuticle which seals in water, making the leaves virtually waterproof.
A thick cuticle can reduce water evaporation from leaves, which is especially important in dry climates or Mediterranean regions with seasonal rainfall. Plants like Adam’s needle (Yucca filamentosa), utilize their cuticle along with their stomata to conserve moisture, enabling them to thrive even during times of extreme dryness outside.
Another way plants protect themselves from evaporation is by dropping their leaves during dry spells. This allows them to enter a dormant state, similar to torpor in animals.
Many cacti and other succulents boast thick leaves due to their ability to store water, helping them survive drought conditions. Some cacti and succulents even feature spines on their stems which aid in collecting moisture, shading the roots, and protecting them from herbivores that could consume them.
Some cactuses and other succulents have thin leaves to reduce water loss through transpiration. Examples include Joshua trees and Yucca family members with narrow, pointed forms which make it harder for their leaves to lose water through transpiration.
Some plants that shed their leaves during dry spells also possess a resinous or waxy coating to slow water loss, such as creosote bush and bursage. This enables them to survive months or even years without rainfall.