Ecological Adaptions, Succession and Ecological Services (VSAQs)
Botany-1 | 13. Ecological Adaptions, Succession And Ecological Services – VSAQs:
Welcome to VSAQs in Chapter 13: Ecological Adaptions, Succession And Ecological Services. This page includes the most important FAQs from previous exams. Each question is answered in a concise format to help you understand quickly and aim for top marks in your final exams.
VSAQ-1: Why does secondary succession reach the climax stage faster than primary succession?
Existing Soil and Plant Remnants
Secondary succession often reaches the climax stage more quickly than primary succession. This is because secondary succession occurs in areas where there is already existing soil and plant remnants. For example, imagine an abandoned field that once supported grasses and small plants. When this field is left undisturbed, it can gradually support a more complex plant community. The presence of soil and some existing plants gives new plants a head start, allowing them to grow and establish themselves faster.
Bare Rock in Primary Succession
In contrast, primary succession starts on bare rock or newly formed land, where soil needs to form from scratch. This process is much slower. For instance, after a volcanic eruption, the ground is covered with fresh, hot lava. It takes a long time for soil to develop from the rock and for plants to start growing. Thus, secondary succession is quicker because it benefits from the already-established soil and plant life.
VSAQ-2: Among bryophytes, lichens, and ferns, which is a pioneer species in xeric succession?
Role of Lichens
In xeric (dry) succession, lichens are the pioneer species. They are specially adapted to survive in extremely dry and harsh conditions where other plants might struggle.
Examples of Xeric Environments
For example, in a rocky desert, lichens are often the first organisms to colonize the land. They can withstand the lack of moisture and help break down rocks into soil. This process creates a more suitable environment for other plants to eventually grow.
VSAQ-3: Give two examples of xerarch succession.
Newly Cooled Lava
One example of xerarch succession is the process that occurs on newly cooled lava. After a volcanic eruption, the landscape is covered with fresh, hot lava. Over time, lichens and mosses begin to colonize this barren surface. These pioneering species help to gradually create soil, setting the stage for other plants to grow.
Bare Rock Areas
Another example is bare rock areas where no vegetation is initially present. Over time, lichens, algae, and mosses start to grow on these rocky surfaces. These early colonizers contribute to soil formation and create conditions that allow more complex plant species to establish themselves.
VSAQ-4: What type of land plants can tolerate the salinities of the sea?
Adaptations of Halophytes
Plants that can tolerate high levels of salt are called halophytes. These plants have special adaptations that allow them to thrive in saline environments like salt marshes and coastal areas.
Examples of Halophytes
A well-known example of a halophyte is the mangrove tree (Rhizophora). Mangrove trees grow in the salty water of coastal regions and have developed unique adaptations to manage high salt levels, making them well-suited for their challenging environment.
VSAQ-5: Define heliophytes and sciophytes. Name a plant from your locality that is either a heliophyte or a sciophyte.
Heliophytes
Heliophytes are plants that thrive in direct sunlight. They need plenty of light to grow and flourish. For example, think of Tridax (Tridax procumbens), which you might find in sunny areas around Hyderabad. This plant loves the sun and does best when exposed to plenty of light.
Sciophytes
On the other hand, sciophytes are plants that prefer shady places with less light. They are adapted to grow well in the shade, like in a dense forest or under a canopy. Ferns, which you might see in shaded forested areas, are great examples of sciophytes. They grow well where sunlight is limited and can thrive in these cooler, shaded conditions.
VSAQ-6: Define population and community.
Population
A population refers to a group of similar individuals of the same species living in a specific geographic area or habitat. For instance, if you look at a group of peacocks living in a forest in Andhra Pradesh, they all belong to the same species and form a population.
Community
A community is made up of several different populations of various species that live together and interact within the same area or ecosystem. Imagine a forest where you have different populations like trees, birds, insects, and animals. All these populations interacting in the forest form a community.
VSAQ-7: Define communities. Who classified plant communities into hydrophytes, mesophytes, and xerophytes?
Communities
A community is an assembly of multiple populations of different species coexisting and interacting in the same area. For example, a pond can be a community with various populations of fish, aquatic plants, and insects all living and interacting together.
Eugen Warming’s Classification
The scientist Eugen Warming is known for classifying plant communities into hydrophytes, mesophytes, and xerophytes. These classifications are based on the plants’ adaptations to different environments: hydrophytes for aquatic environments, mesophytes for moderate conditions, and xerophytes for arid, dry environments.
VSAQ-8: Why do hydrophytes show reduced xylem?
Hydrophytes and Xylem Reduction
Hydrophytes are plants that live in water-rich environments, such as ponds or marshes. They have reduced xylem because they absorb water through their entire surface, including their submerged parts. Unlike terrestrial plants that need extensive xylem to transport water from roots to leaves, hydrophytes don’t require such extensive water transport mechanisms. This adaptation helps them efficiently use the abundant water around them.