Chapter 18: Productivity

These flashcards cover key concepts about productivity, primary production, nutrient cycling, and the roles of various organisms in ecosystems.

What generally limits terrestrial primary production?

Temperature, moisture, and nutrients.

How does aquatic primary production differ from terrestrial?

Aquatic primary production is generally limited by nutrient availability.

What is Gross Primary Production (GPP)?

The total primary production by all primary producers in an ecosystem.

What is Net Primary Production (NPP)?

NPP is calculated as GPP minus respiration by primary producers and represents the amount of energy available to consumers.

Define primary production.

The creation of new biomass or organic matter by an individual, population, community, or ecosystem per unit time.

What are trophic cascades?

Trophic cascades occur when consumers influence the rates of primary production in ecosystems.

What is the role of chlorophyll in primary production?

Chlorophyll absorbs light for photosynthesis, which is vital for primary production.

What abiotic factors affect primary production?

Temperature, rainfall, photoperiod, nutrients, and disturbances.

What is the Trophic Cascade Hypothesis?

The hypothesis that effects of predators on prey can alter more than one trophic level.

How does increased biodiversity affect primary production?

Higher species richness generally leads to higher primary production.

What are the two major types of electromagnetic radiation mentioned?

Visible light and ultraviolet.

What effect does nitrogen have on primary production in meadows?

Nitrogen is the main nutrient limiting net primary production in a dry alpine meadow.

What are bottom-up and top-down controls in ecosystems?

Bottom-up controls are physical and chemical factors, while top-down controls are influenced by consumers.

What role do grazers play in primary production?

Grazers can increase primary production by consuming significant amounts of biomass but also affect soil fertility and water balance.

How does light wavelength affect photosynthesis?

Photosynthetically available radiation (PAR) is the range of light wavelengths that can be used in photosynthesis.

What is the significance of Liebig's Law of the Minimum?

It states that the nutrient in shortest supply will limit ecosystem productivity.

Explain the Nitrogen Cycle.

The cycle involves nitrogen fixation, assimilation, nitrification, and denitrification processes through various organisms.

What is biomass?

Organic matter found within a defined area, usually living.

What type of analysis is used to trace energy flow through ecosystems?

Stable Isotope Analysis.

What did Rosenweig's 1968 study show concerning terrestrial primary production?

It suggested that moisture and temperature significantly influence rates of production.

In what form is phosphorus primarily stored in ecosystems?

It is primarily found bound in sediments, rocks, and soils as an inorganic form.

How does respiration relate to primary production?

Respiration is the metabolic process by which organisms obtain energy, reducing the amount of biomass available for primary production.

What factors can influence decomposition rates?

Temperature, moisture, and the chemical composition of litter and the environment.