Plants are crucial to an ecosystem because they significantly contribute to water sources. Through their roots, they absorb water from the soil and release it back into the environment through their leaves, thereby minimizing soil erosion.
The water cycle consists of four major stages: evaporation, condensation, collection and precipitation. This essential cycle helps sustain life on Earth.
Photosynthesis
Photosynthetic cells in plants use sunlight, water and carbon dioxide to make glucose, a form of sugar essential for growth. The process uses energy from light to rearrange molecules of carbon dioxide and water into food molecules (glucose).
Photosynthesis by plants and other organisms is essential to the Earth’s ecosystem, as it produces most of the energy that drives life on this planet. Furthermore, photosynthesis generates biomass which helps turn sunlight into fossil fuels – now an indispensable source for modern economies.
Plants play an essential role in the water cycle, as they require water for photosynthesis and release oxygen into the atmosphere as they grow. Furthermore, plants provide much-needed nutrients to our soils and oceans which support life and enhance environmental quality.
Photosynthesis occurs when a plant absorbs carbon dioxide from the air and water from soil through tiny holes in its leaves, flowers, roots, branches or stems. This carbon dioxide is then transformed into oxygen gas that is released back into the atmosphere as well as back into any water that passes through it.
Photosynthesis uses oxygen to make other molecules, like proteins that form the structure of a plant. These chemicals are then utilized as energy sources to support growth and repair within the plant.
In addition to these chemical processes, plants also employ photorespiration. This occurs when the plant is exposed to intense sunlight and reduces the amount of photoproduced superoxide and hydrogen peroxide that could potentially harm molecules within its chloroplasts.
This is accomplished by scavenging active oxygens that are not necessary for photosynthesis and dissipating excess photon energy and electrons. This prevents oxidative damage to chloroplasts, as well as protecting against sunburn.
Another way plants contribute to the water cycle is through their role in controlling carbon uptake by other organisms, known as “carbon balance.” This balance can be affected by various factors like changes in atmospheric carbon dioxide levels and land dryness. Alterations to this balance can negatively impact species’ growth and health, making plants less nutritious and unable to resist disease effectively.
Transpiration
Transpiration is an essential process that helps plants regulate their water balance. It also plays a major role in creating a healthy atmosphere for living organisms, particularly those unable to absorb water through other means.
Transpiration occurs when liquid water in plants evaporates into a vapor that escapes through minute pores (stomata) on their leaves or tiny openings called lenticels in their bark. Stomatal transpiration is the major source of water loss from plants and accounts for nearly 90% of water lost through leaf surfaces.
Stomatal openings on plants open and close according to factors like light availability and airborne carbon dioxide concentrations. They also regulate water absorption through the roots, helping the plant maintain its own water balance while taking nutrients from soil up into stems and leaves.
Stomata are small holes in the leaves that allow oxygen and carbon dioxide to pass for photosynthesis. When the plant is active, these pores open to let in carbon dioxide while staying closed at rest to prevent excessive evaporation of water.
On dry days, stomata expand and open to release water vapor during transpiration to keep plants cool and pull up groundwater through their roots to the leaves. Conversely, in wet or cold weather these openings shrink, preventing excessive evaporation from the leaves while decreasing groundwater absorption through their roots.
The rate at which water moves through a plant through transpiration depends on temperature, relative humidity and wind. Wind increases the amount of water that leaves a plant’s leaves as it replaces saturated air with less-saturated air.
Warm temperatures increase the water potential gradient of a leaf, encouraging more water evaporation and raising transpiration rates. Conversely, dry conditions cause this gradient to be steeper, encouraging more water evaporation and slowing transpiration through plants’ leaves.
Infiltration
The water cycle consists of six primary processes: evaporation, condensation, precipitation, runoff, infiltration and groundwater recharge. These purifying and dispersing processes provide freshwater around the world – essential for human life as well as other plants.
Infiltration occurs when rainwater seeps into the soil, keeping it healthy and stable while also preventing soil eroding that could lead to flooding.
Infiltration occurs in a variety of soil types, from sandy to clay. Its rate depends on the type of soil, how it’s cultivated or eroded, rainfall amounts, vegetation cover and land use.
The texture of soil, or its percentage of sand, silt and clay, determines how quickly water moves through its pores. A sandy soil will move water more quickly than one with more clayey particles. Furthermore, texture affects how much moisture the soil retains as well as how quickly it can absorb moisture.
Vegetation cover has an immense effect on water infiltration, protecting soil from intense precipitation and increasing its capacity to absorb water. Vegetation such as tree stems and leaves also acts as a deterrent to runoff.
Another way plants contribute to the water cycle is by encouraging percolation and recharge of groundwater. This occurs when soil moisture from rainfall or irrigation is increased. As this water seeps into the ground, it travels down through the root zone of plants until reaching underlying rock or soil.
Water absorbed into the soil can then be stored and used by plants or other organisms such as worms. Depending on the type and saturation level of the soil, infiltration can take anywhere from minutes to hours or even days depending on conditions. Infiltration plays an integral role in replenishing groundwater supplies – an integral element of Earth’s ecosystem.
Evaporation
Evaporation is the process by which water transforms from a liquid to gas or vapor. This occurs due to heat energy that breaks apart molecular bonds that keep molecules together in liquid state.
Evaporation of water from oceans, lakes and rivers is an integral component of Earth’s water cycle. Without it, rain would never fall, snow wouldn’t form and soils, crops and human life could be deprived of freshwater sources.
On Earth’s largest bodies of water (the oceans, seas and rivers), heat from the sun causes vast amounts of water to evaporate into the air as water vapor. Estimates suggest that 90 percent of our atmosphere’s moisture comes from this process.
Evaporation occurs in a number of ways, including over land and at sea. Evaporating water from the seas is especially significant because it helps to counteract the greenhouse effect caused by carbon dioxide and other gases.
Evaporation also cools the sea surface, helping to prevent it from freezing in wintertime. Wind also plays a significant role in this process by moving around water vapors that accumulate.
As water vapor ascends to high altitudes, it transforms back to water molecules through condensation. At these altitudes, tiny droplets of ice and water condense together due to the cold temperature; creating clouds and fogs visible in the sky.
Plants play an essential role in controlling the water cycle through transpiration, which is a natural cooling process that occurs naturally throughout all plants. Transpiration is activated when there is an imbalance of water between what has been taken in from soil and what needs to be released into the air.
Additionally, sublimation contributes a small amount of moisture to the atmosphere by turning water vapor into tiny ice particles when exposed to cold air. Though less-known, this function of water vapor plays an important role in keeping Earth from freezing over.
