Ecology and Global Change Practice Flashcards

This flashcard set covers the reciprocal influence of organisms and the environment, biogeochemical cycles (carbon, nitrogen, phosphorus), and the impacts of human activity on biodiversity and climate.

Primary Producers

The base of trophic pyramids that generate $O_2$; carbon accumulates in the atmosphere when their organic carbon is buried rather than respired.

Decomposers

Organisms that play a critical role in the carbon cycle by returning carbon to the atmosphere as $CO_2$ through respiration.

Tree Evolution

A historical biological event that caused a large decline in atmospheric $CO_2$ and increased oxygen levels to support more organisms.

Biodiversity

The total number of species, or, more broadly, the diversity of genetic sequences, cell types, metabolisms, life histories, phylogenetic groups, communities, and ecosystems.

Ecosystem Engineer

A keystone species that shapes the physical environment, often creating habitats for others, such as humans participating in habitat modification.

Conservation Biology

The efforts by biologists and policy makers to address the challenge of sustaining biodiversity in a changing world and with a growing human population.

Amphibians

The vertebrate taxon identified in Fig 48.23 as having the sharpest population declines.

Keeling Curve

A graphical representation showing that atmospheric carbon oscillates seasonally and has increased significantly since the Industrial Revolution.

Sedimentary Rocks

The largest carbon reservoir, representing the long-term storage of carbon.

Ice Cores

Samples drilled from glaciers used to analyze atmospheric conditions from the recent past, approximately $1000$ to $800000$ years ago.

Glacial Period $CO_2$ Concentration

The level of atmospheric carbon during glacial periods, measured at approximately $180\,\text{ppm}$.

Interglacial Period $CO_2$ Concentration

The level of atmospheric carbon during interglacial periods, measured at approximately $280\,\text{ppm}$.

Greenhouse Gas

A gas that allows incoming solar radiation to reach Earth but absorbs radiation re-emitted as heat, trapping it in the atmosphere and raising temperatures.

Ocean Acidification

A decrease in the $pH$ of seawater caused by an increase in oceanic $CO_2$, which reduces carbonate ions needed for shells and skeletons.

Carbon Isotopes

Measurements used to show that current atmospheric $CO_2$ increases are derived from the combustion of fossil fuels rather than natural sources.

Limiting Nutrients

The substance in lowest supply relative to the needs of primary producers, which determines the rate of photosynthesis in an environment.

Nitrogen-fixation

The process by which some Bacteria and Archaea convert nitrogen gas into ammonia, making it biologically useful for primary producers.

Phosphorus

A vital nutrient for metabolism and a central element of $ATP$, primarily found in rock reservoirs rather than the atmosphere.

Eutrophication

The process where the addition of nutrients to a body of water stimulates the overgrowth of plants, algae, and cyanobacteria.

Dead Zones

A consequence of eutrophication where an overabundance of life at the surface leads to a lack of life at the bottom of a water body.