W3 Ecology, Marine Biogeochemistry, and Atmospheric Protection Flashcards

Flashcards covering general ecology, biodiversity, the impacts of ocean acidification on silica and coral reef cycles, and the history and protection of the atmospheric ozone layer.

Ecology

The scientific study of the distribution and abundance of organisms and the interactions between organisms and their environment.

Taxonomy

The practice of classifying organisms into hierarchical groups; historically started by Linnaeus with two kingdoms (Animalia and Vegetabilia) and currently expanded to six kingdoms according to Cavalier-Smith (1998).

Cladistics

A classification method based on shared attributes and hypothetical evolutionary history to provide a general picture of classification.

Phylogenetics

A methodology of classifying organisms based on genetics and technology to show evolutionary relationships between groups.

Species

A group of organisms that can interbreed to produce fertile offspring.

Community

An assemblage of populations of different species living and interacting with each other in a specific area.

Ecosystem

The biological community and its interactions with the abiotic (non-living) environment.

Niche

How a species fits into its environment, its role, and how it survives, including where it lives, what it eats, and its ecological function.

R-strategists

Organisms that typically have a small size at birth, short lifespans, low parental care, and Produce a large quantity of offspring.

K-strategists

Organisms characterized by large relative size at birth, long lifespans, high parental care, and fewer offspring, focusing on quality over quantity.

Redundancy (Ecological)

The presence of multiple species capable of fulfilling the same ecological role, making the system less likely to be negatively impacted if one species goes extinct.

Functional Biodiversity

A measure of the variety of ecosystem functions completed by species (e.g., grazers, carbon fixing, nitrogen fixing) to maintain system balance.

Genetic Biodiversity

The variety of genes within a single species, which provides a greater chance of surviving changes like disease, pollution, or climatic shifts.

Diatoms

The dominant group of silicifiers in the ocean, accounting for up to $40\%$ of marine primary production and requiring silicic acid ($Si(OH)_4$) for growth.

Frustules

The opaline shells of diatoms formed through the biomineralization of silicic acid.

Ocean Acidification (OA)

The process by which the ocean's uptake of atmospheric $CO_2$ causes an increase in seawater hydrogen ion concentration, leading to a decrease in pH and carbonate ions ($CO_3^{2-}$).

Silicate Pump

The mechanism by which biogenic silica is transferred from the surface to the deep ocean, which can be amplified by OA due to slower chemical dissolution of silica at lower pH.

Saturation State (\Omega)

An index describing the tendency for carbonate minerals to precipitate or dissolve, defined by the formula $\Omega_{CaCO3} = [Ca^{+2}][CO_3^{2-}]/K^*{SP}$.

Aragonite

A common mineral form of calcium carbonate used by marine calcifying organisms; its saturation state in the Caribbean has declined by approximately $3\%$ relative to pre-industrial levels.

Pseudocalanus acuspes

A calanoid copepod species that dominated the Gullmar Fjord mesocosm experiment and showed a tendency toward increased biomass under simulated ocean acidification due to indirect food web stimulations.

Particle Size Spectrum (PSS)

A representation of the relationship between the abundance of particles and their size, often showing an inverse linear relationship on a logarithmic scale.

Ozone ($O_3$)

A naturally occurring substance in the atmosphere that removes harmful ultraviolet radiation from the sun; its peak concentration is at an altitude of approximately $25\,km$ near the equator.

Dobson Unit (DU)

The standard unit of ozone column amount; one DU is equivalent to $2.68 \times 10^{16}\,molecules\,cm^{-2}$, with $300\,DU$ representing a $3\,mm$ thick column at STP.

Chapman Cycle

A cycle of chemical reactions proposed by Sydney Chapman (1930) where ozone is created by the photolysis of $O_2$ and maintained through a sun-driven balance of creation and destruction.

Chlorofluorocarbons (CFCs)

Stable, non-toxic engineered molecules originally used in refrigeration that, upon reaching the stratosphere, undergo photolysis to release reactive chlorine which destroys ozone.

Montreal Protocol

A global environmental agreement signed in 1987 to protect the ozone layer by imposing international controls on the use and emission of ozone-depleting substances.

Polar Stratospheric Clouds (PSCs)

Clouds that form at temperatures below $195\,K$ in polar regions, facilitating surface reactions that release chlorine atoms for rapid ozone destruction when sunlight returns.