Aquatic, Mountain, and Desert Ecosystems | Ch 13,14 | EVS

Review Quiz

1. What are the two primary categories of aquatic ecosystems, and what percentage of the Earth's surface do they cover respectively?
2. Describe the key characteristics that differentiate lentic and lotic freshwater ecosystems, providing an example for each.
3. What are the three distinct zones found within lakes and ponds, and where are they located?
4. Explain the ecological significance of estuaries and identify the primary threats they face from human activities.
5. What are the three ecological zones of a mountain ecosystem discussed in the source material, and what are their general elevation ranges?
6. How do coral reefs form, and what are two of the crucial ecosystem services they provide?
7. Identify the three main desert ecosystems in India and a unique characteristic of each.
8. According to the source, what percentage of the Earth's liquid freshwater is stored as groundwater, and why is this resource vital?
9. Name two iconic animal species found in the cold desert of Ladakh and describe the environmental conditions they are adapted to.
10. List four of the conservation strategies proposed for protecting desert ecosystems.

Answer Key

1. The two primary categories are freshwater and marine ecosystems. Marine ecosystems, which include oceans, seas, and estuaries, cover about 71% of the Earth's surface, while freshwater ecosystems, like lakes and rivers, occupy a mere 0.8% of the Earth's surface.
2. Lentic and lotic ecosystems are distinguished by their water flow. Lentic ecosystems, such as lakes and ponds, feature still or slow-moving water, leading to stratification and stable environments. Lotic ecosystems, like the Amazon and Ganges rivers, are characterized by continuously moving water, which results in higher oxygen content.
3. The three zones are the littoral zone, the limnetic zone, and the profundal zone. The littoral zone is located near the shore, the limnetic zone is in the open water, and the profundal zone is found in the deeper areas of the lake or pond.
4. Estuaries are highly productive transitional zones where freshwater rivers mix with saltwater from the ocean. They serve as critical habitats, filter pollutants, absorb floodwaters, and support commercial fisheries. They are threatened by pollution, habitat destruction, and climate change.
5. The three zones are the Mountain Zone (approx. 3,000 to 7,000 ft), the Subalpine Zone (approx. 7,000 to 10,000 ft), and the Alpine Zone (begins above the tree line, around 10,000 ft). The Mountain Zone has diverse forests, the Subalpine Zone is characterized by coniferous forests, and the Alpine Zone features cold temperatures and rocky terrain.
6. Coral reefs are underwater ecosystems formed by the accumulation of calcium carbonate structures created by coral polyps in warm, shallow waters. They provide crucial ecosystem services by protecting coastlines from erosion and storm damage and by providing habitats for commercially valuable fish species, which supports global fisheries.
7. The three main deserts are the Thar Desert, the Run of Kutch, and the cold desert of Ladakh. The Thar Desert is the largest in India, characterized by rolling sand dunes. The Run of Kutch is a vast salt marsh desert formed by seasonal flooding from the Arabian Sea. The cold desert of Ladakh is a high-altitude desert with extreme temperatures and minimal precipitation.
8. Groundwater constitutes an estimated 30% of the world's liquid freshwater. It is a vital resource because it serves as a primary source of drinking water for many communities, supports agriculture, and contributes to the flow of rivers and streams.
9. Two iconic species are the Tibetan wild ass (Kyong) and the snow leopard. They are adapted to the high-altitude environment, which is known for extreme temperatures, harsh winters, short summers, and sparse vegetation.
10. Four proposed conservation strategies for desert ecosystems include: establishing and expanding protected areas; implementing habitat restoration projects; promoting water conservation practices; and encouraging sustainable land use practices that minimize habitat destruction.

Essay Questions

1. Compare and contrast the primary threats facing marine ecosystems (oceans, coral reefs, estuaries) with those facing terrestrial arid ecosystems (deserts), using specific examples mentioned in the lectures.
2. Discuss the critical role of freshwater ecosystems, both lentic and lotic, in sustaining global biodiversity and supporting human communities, despite their limited spatial coverage on Earth.
3. Explain how altitude creates distinct ecological zones within a mountain ecosystem. Describe the characteristics of the Alpine, Subalpine, and Mountain zones as detailed in the source material.
4. Analyze the concept of "ecosystem services" by providing specific examples from wetlands, coastal areas, and mountain ecosystems. How do these services highlight the importance of conservation?
5. Using the examples of the Bishnoi community in Rajasthan and the challenges in the Run of Kutch, discuss the conflict between large-scale development projects and the preservation of fragile desert ecosystems and their endemic species.

Glossary of Key Terms

Term	Definition
Alpine Zone	A high-altitude ecological zone characterized by cold temperatures, rocky terrain, and the presence of snow and ice, typically beginning above the tree line at elevations around 10,000 feet (3,000 m).
Aquatic Ecosystem	Diverse habitats encompassing bodies of water like oceans, rivers, lakes, and wetlands, where water plays a central role.
Benthic Zone	The ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers.
Chinkara	The common name for the Indian gazelle, an agile antelope well-adapted to the arid landscapes of the Thar Desert, capable of surviving for extended periods without water.
Coastal Areas	Dynamic regions where land meets the sea, encompassing habitats such as beaches, dunes, salt marshes, and mangrove forests, which protect inland areas from erosion and storms.
Cold Desert of Ladakh	A high-altitude desert in northern India, located between the Himalayan and Karakoram mountain ranges, known for extreme temperatures, minimal precipitation, and sparse vegetation.
Coral Reefs	Intricate and vibrant underwater ecosystems formed by the accumulation of calcium carbonate structures from coral polyps, thriving in warm, shallow, nutrient-rich tropical waters.
Desert Ecosystem	Regions with highly specialized and delicate ecosystems, where endemic flora and fauna have evolved to thrive exclusively within their specialized arid habitat.
Estuaries	Dynamic and productive transitional zones where freshwater from rivers meets and mixes with saltwater from the ocean, characterized by fluctuating salinity and nutrient-rich waters.
Freshwater Ecosystem	Ecosystems comprising lakes, rivers, and wetlands that occupy approximately 0.8% of the Earth's surface but hold 9% of the planet's total water.
Groundwater	Water stored underground in aquifers, constituting around 30% of the world's liquid freshwater, replenished by the percolation of rain and surface water.
Kyong	The local name for the Tibetan wild ass, a notable species found in the high-altitude cold desert of Ladakh.
Lentic Ecosystem	Still or slow-moving bodies of freshwater such as ponds, lakes, and wetlands, characterized by low flow rates and distinct stratification of water layers.
Limnetic Zone	The open-water zone in a lake or pond, away from the shore.
Littoral Zone	The zone in a lake or pond that is near the shore.
Lotic Ecosystem	Freshwater ecosystems characterized by the continuous movement of water, such as in rivers and streams, resulting in dynamic habitats and high oxygen content.
Marine Ecosystem	Ecosystems formed in bodies of saltwater, primarily oceans, seas, and estuaries, which cover about 71% of the Earth's surface.
Mountain Ecosystem	A biological community of organisms and their physical environment within a mountainous region, characterized by high altitudes, steep slopes, and diverse microclimates.
Mountain Zone	An ecological zone on a mountain situated at lower elevations, typically from 3,000 to 7,000 feet, characterized by diverse vegetation including deciduous and evergreen forests.
Phytoplankton	Microscopic primary producers that form the base of marine food webs, supporting a complex network of life.
Profundal Zone	The deep zone in a lake or pond, located below the range of effective light penetration.
Run of Kutch	A vast salt marsh desert in Gujarat, India, formed by the seasonal flooding and drying of shallow waters from the Arabian Sea, known for its salt flats and salt-tolerant plants.
Subalpine Zone	An ecological zone situated below the Alpine zone, typically from 7,000 to 10,000 feet, characterized by the presence of coniferous forests and meadows.
Thar Desert	Also known as the Great Indian Desert, an arid region spanning northwestern India and southeastern Pakistan, characterized by rolling sand dunes and extreme temperatures.
Wetlands	Vital ecosystems, including marshes, swamps, and bogs, that serve as transitional zones between terrestrial and aquatic environments, covering approximately 6% of the Earth's land surface.