Hydrarch Succession

Hydrarch Succession takes place in freshwater habitats, such as ponds, lakes, or wetlands. The hydrarch succession studied in class 12 describes the gradual colonization and replacement of plant species in waterbodies. Hydrarch succession stages involve the sequential development of plant communities in aquatic environments, starting with pioneer species like algae and ending with the establishment of climax communities like marshes.

Abiotic and biotic variables interacting with one another and changes in the environment cause this process. In this article, we will cover the hydrarch succession types, stages, pioneer species, and more in detail.

An ecological succession known as “hydrarch succession” only occurs in water bodies. On bare surfaces like rocks or silt, it starts with colonizing pioneer species, typically algae or floating plants. By retaining sediment, adding more organic matter, and changing the availability of nutrients, these pioneer species change the ecosystesm. The pioneer species are eventually replaced by other plant species, such as emergent and submerged macrophytes, as the environment changes. This process is repeated until a climax community a stable, self-sustaining community typical of the specific ecosystem is formed.

The organisms that are among the first to colonize empty spaces in aquatic habitats are known as the pioneer community in hydrarch succession. These species have certain traits and adaptations that allow them to survive in harsh conditions.

• Fast Growth: Pioneer species are able to swiftly establish themselves in newly accessible habitats because they usually have systems in place for both fast growth and reproduction.
• Tolerance to Harsh Conditions: Pioneer species are frequently able to withstand harsh environmental factors including intense sunshine, unstable water levels, and a lack of nutrients.
• Capacity to Fix Carbon: A lot of pioneer species, including cyanobacteria and algae, can fix carbon by using sunlight and carbon dioxide to make organic molecules, which is necessary for their survival and growth.
• High Reproductive Capacity: In order to effectively colonize new environments, pioneer species frequently have high rates of reproduction, generating enormous quantities of spores, seeds, or other reproductive structures.
• Attachment Adaptations: They have developed adaptations that enable them to adhere to substrates making it easier for them to establish themselves on surfaces like rocks or silt.

An ecosystem that has attained equilibrium is known as the climax community.

• In freshwater ecosystems, the climax community of hydrarch succession may consist of diverse vegetation such as trees, shrubs, and emergent aquatic plants.
• This community provides habitat for various aquatic organisms and supports a rich biodiversity.
• It helps stabilize the ecosystem by regulating water flow, nutrient cycling, and providing food and shelter for wildlife.
• Examples include mature forests surrounding freshwater lakes or wetlands.

There are several stages of hydrarch succession which are listed below:

Phytoplanktons Stage

• Protoplankton is the first stage.
• These plants are those that reside in the water’s lowest stratum.
• Green algae, blue-green algae, and diatoms are some of them.
• Sunlight provides them with energy, and water and soil provide them with nutrition.
• Depending on the amount of sunshine the pond receives, the amount of nutrients it contains, and its depth, the phytoplankton stage can last anywhere from a few days to several years.

Root Submerged Stage

• In the second stage, known as the root immersed stage, plants develop roots in the water to get nutrients from the soil.
• Depending on the amount of sunshine pond receives, its depth, and the amount of nutrients it receives from decomposing leaves, this stage might last for a few weeks to several years.

Rooted Floating Stage

• This phase may be regarded as the first phase of succession.
• This stage is characterized by the growth of floating plants such as water ferns (Azolla sp.), duckweed (Lemna sp.), and water hyacinth (Eichhornia crassipes).
• The roots of these plants do not go below the water’s surface; instead, they float atop it. Through their leaves, they take up nutrients from the top soil layers.
• Since these plants’ roots are limited to the soil’s outer layer, disturbances like storms or floods can quickly uproot them.
• Even though the rooted aquatic plants are susceptible to being uprooted by strong winds and storms, their highly developed root systems allow them to rapidly re-establish themselves in the soil under the water’s surface.

Reed-Swamp Stage

• At this point, a few of the early-rooted floating vegetation will perish and drop to the pond’s bottom. This produces an up to 6-inch-thick covering of peat moss on top of the soil.
• “Duff” is the term for this layer. Reeds and other tall grasses gradually cover the duff layer; these plants are caused by bird droppings or wind-borne seeds from adjacent fields.
• Little creatures like frogs, turtles, and snakes as well as mosquito-eating dragonflies and damselflies find refuge in these grasses!

Marsh-Meadow Stage

• The life cycle of the juvenile hydrophytes starts in the Marsh-Meadow Stage.
• It is distinguished by rapid growth rates and low nutritional levels.
• The plants in this area reproduce either by seeds or spores, and their rates of reproduction are modest.
• Water hyacinth (Eichhornia crassipes) and duckweed (Lemna minor) are two examples of this kind of plant.

Woodland Stage

• Following in order is the forest stage, which has more trees than the level before it. In addition to birch trees, these trees also contain poplar, ash, and aspen.
• In addition, there are a few shrubs, such as oak and hazelnut bushes, as well as ferns that grow on the forest floor, grasses, and sedges growing beneath them.
• Due to increased amounts of organic matter added by decomposing plant matter that has fallen to the ground as a result of wind, animal activity, or both, along with a steady supply of water from rainfall that keeps the area sufficiently moist for future plant growth.

Forest Stage

• High availability of resources during the Forest Stage leads to rapid growth rates but moderate reproduction rates because of competition for resources like light, carbon dioxide, and other nutrients like phosphorus and nitrogen.
• Tamarrack (Larix laricina) and balsam fir (Abies balsamea), two conifers that thrive in both Canada and the United States, are examples of this kind of plant.
• As they deciduous trees like hickory trees (Carya spp.) and oak trees (Quercus spp.) shed their leaves every year in the winter when they receive less sunlight, they would be regarded as this kind of forest stage.

Succession is a normal process of ecological change that happens throughout time in a variety of settings, each with unique traits and phases.

• Primary Succession: Takes place in arid regions where no species previously existed. A new volcanic island, for instance.
• Secondary Succession: Takes place in areas when natural disasters like fire or flood have destroyed all of the previous settlements. Example: a forest burned to the ground.
• Autogenic succession: It is the result of organism-environment interaction driving succession on its own. Primary succession is one example.
• Allogenic Succession: It occurs when outside forces alter the ecosystem.
• Autotrophic succession: It refers to the dominance of plants in settings rich in inorganic matter.
• Heterotrophic Succession: In ecosystems rich in organic matter, animals and fungus first take over.
• Progressive Succession: Through a series of adjustments, simple shapes develop into complex forms. For instance, converting grasslands to forests.

For More Information Read: Ecological Succession – Definition, Types, Characteristics, Causes

The movement and direction of hydrarch succession are determined by several variables.

• Hydrological Conditions: The succession process is significantly influenced by water depth, flow velocity, and nutrient availability. Changes in these variables may have an impact on the development and makeup of aquatic plants.
• Substrate Characteristics: During succession, the development and establishment of plant species are influenced by the substrate’s characteristics, including its rocky, sandy, or muddy texture.
• Nutrient Availability: By influencing plant growth and competitiveness, the availability of nutrients, especially nitrogen and phosphorus, can impact the rate and direction of succession.
• Disturbance Events: By changing the environment and the balance of competition between species, disturbances like flooding, droughts, or human activity can impede succession.
• Biotic Interactions: By affecting species composition and community structure, competition, predation, and mutualistic connections among organisms also shape the dynamics of hydrarch succession.

The major difference between hydrarch succession and xerarch succession is given below:

In summary, the process of hydrarch succession is essential to the growth and modification of aquatic environments. Hydrarch succession results in the growth of emergent vegetation and woody plants, as well as the colonization of pioneer species like as algae and cyanobacteria, which together create stable and diversified climax ecosystems. For the sake of managing ecosystems and promoting conservation and restoration, it is essential to understand the phases and dynamics of hydrarch succession.

Also Read:

• Ecological Succession – Definition, Types, Characteristics, Causes
• Difference Between Primary And Secondary Succession
• Ecosystem Notes Class 12 Biology Chapter 12
• The Functions of Ecosystem
• Ecological Pyramid

What is Hydrarch and Xerarch Succession?

Hydrarch succession occurs in aquatic environments, while xerarch succession occurs in terrestrial environments, both involving the sequential colonization and replacement of plant species over time.

What is Hydrarch Succession Stage?

It begins with phytoplankton, followed by rooted submerged plants, floating plants, free-floating plants, reed swamp, marsh meadow, scrub, and culminates in the climax or tree stage, the final phase.

What is the Succession of Animal Communities Through Hydrarch?

Hydrarch succession, starting in ponds and lakes, begins with pioneer communities like phytoplankton, culminating in forest formation.

Where does Hydrarch Succession Occur?

Hydrarch succession occurs in aquatic environments, such as ponds, lakes, and wetlands.

What would be the Climax of a Hydrarch Succession?

The climax of a Hydrarch succession is the establishment of a stable forest ecosystem.

What is Phytoplankton Stage?

The phytoplankton stage marks the beginning of hydrarch succession in aquatic environments, with colonization by microscopic algae.