Chapter 19 Ecology

it is stored by autotrophs and transferred to heterotrophs

total amount of carbon fixed by autotrophs in an ecosystem.

leaf area per unit of ground area.

 NPP = GPP – respiration

plant biomass gained NPP is allocated among growth, reproduction, storage, and defense NPP allocated to leaves, stems, and roots depends on resource availability of light, nutrients, water, and carbon NPP allocated to storage compounds is insurance

Source  for energy traveling to upper trophic levels Variation provides information on ecosystem change Closely tied to global carbon cycle; carbon moving from atmosphere into ecosystems

Roots turnover much more rapidlyRoots transfer carbon to mycorrhizal or bacterial symbiontsMore frequent correction factorsalgorithms that relate above to

• Harvesting aboveground plant biomass before and after the growing seasonScale estimates up to the ecosystem
• Provides a destructive estimate of NPP

Net Ecosystem Exchange (NEE)

precipitation and temperature

Declines at higher precipitation because cloud cover limits photosynthesis and rain leaches nutrients from soils.

increasing temperature.

phytoplankton and is mostly limited by nitrogen

kelp forests and seagrass beds. Equatorial Pacific ocean, nitrogen can be detected in the water