Question

The most highly productive terrestrial ecosystems are a. deserts. b. prairies. c. forests. d. savannas. e. tundra.

Short answer

The most highly productive terrestrial ecosystems are c. forests.

Step-by-step solution

Understanding Ecosystem Productivity

Ecosystem productivity refers to the amount of energy that is produced by plants, which is also known as the primary productivity. This is usually measured in terms of biomass produced per unit area over a given period of time. Different ecosystems have different levels of productivity depending on factors such as sunlight availability, temperature, nutrient availability, and rainfall.

Comparing the Productivity of Different Ecosystems

Deserts, tundra, and savannas are typically less productive due to extreme temperatures, inadequate rainfall, and nutrient-poor soils. On the other hand, prairies are more productive but still less compared to other ecosystems because of their moderate temperature and rainfall. Forests, especially tropical rainforests, are the most productive terrestrial ecosystems thanks to their warm temperatures, high rainfall, and abundant sunlight.

Key concepts

Primary Productivity

Primary productivity is a critical concept in ecology. It refers to the rate at which energy is converted by photosynthetic and chemosynthetic autotrophs to organic substances. In simpler terms, it's all about how plants and algae can produce food through processes like photosynthesis.
Plants capture sunlight and transform it into the chemical energy found in organic compounds. This energy becomes the basis for nearly all life on Earth. The amount of energy available to an ecosystem depends on its primary productivity.

• Gross Primary Productivity (GPP) - the total rate of photosynthesis in a given area.
• Net Primary Productivity (NPP) - the GPP minus the energy used by plants for respiration, which contributes to biomass accumulation.

In essence, primary productivity sets the stage for energy flow and nutrient cycling within ecosystems.

Terrestrial Ecosystems

Terrestrial ecosystems refer to ecosystems that are found on land. These include forests, prairies, deserts, tundras, and more. Each type of terrestrial ecosystem features unique characteristics influenced by climate, soil type, and the presence of various flora and fauna.
Terrestrial ecosystems are critical for life on Earth. They provide a vast array of ecological functions:

• They act as carbon sinks, absorbing carbon dioxide and releasing oxygen through photosynthesis.
• They maintain biodiversity, offering habitats to different species.
• They regulate climate by influencing local and global weather patterns.

The productivity of terrestrial ecosystems varies significantly. Tropical forests are known for high productivity, while deserts and tundras have much lower productivity due to harsher climate conditions.

Biomass Production

Biomass production is a crucial component in determining an ecosystem's health and potential as a resource. Biomass refers to the total mass of living organisms in a particular area, and in ecology, it's typically associated with plant matter.
The higher the biomass production, the more robust the ecosystem. Biomass production includes the accumulation of organic matter, and it provides food and habitat for countless organisms. It is measured in grams or kilograms per square meter or hectare.
Factors influencing biomass production include:

• Sunlight - essential for photosynthesis.
• Water availability - critical for plant growth.
• Nutrient-rich soil - supports healthier plant life.

Biomass production is a direct indicator of the net primary productivity of an ecosystem.

Tropical Rainforests

Tropical rainforests are some of the most ecologically important and biologically diverse ecosystems on our planet. Known for their extensive canopy and rich biodiversity, they’re considered the most productive terrestrial ecosystems. These forests are located near the equator, where the climate is warm and wet year-round, creating an ideal environment for a multitude of plant and animal species. The combination of abundant warmth, sunlight, and rainfall promotes high levels of primary productivity and biomass production.
Some key features of tropical rainforests include:

• Dense tree canopies that capture a significant amount of sunlight.
• A high level of species diversity and ecosystem complexity.
• A crucial role in carbon storage, thus helping regulate the global climate.

The health and sustainability of tropical rainforests are essential for maintaining ecological balance and supporting biodiversity across the globe.