An ecology research project aims to understand how reducing habitat size impacts extinction rates of a beetle species. Relevant data include the number of beetles that are captured over time in habitats of different sizes. This question focuses on what subfield of ecology?

population ecology.

Explanation:

Population ecology is a subfield of ecology in which the ecologists study various aspects of ecology such as habitat, temperature or other environmental factors which are responsible for the increase or decrease in the population of particular specie. In this subfield of ecology, we study that how is the population changes over time and why the population changes with the passage of time or what factors are responsible for this change.

4.) metal

"-the movement of carbon from the nonliving environment into living things and back to the environment

-carbon is the essential component of proteins, fats, and carbohydrates (which make up all organisms)

-carbon exists in air, water, and living organisms

-producers convert carbon dioxide in the atmosphere into carbohydrates during photosynthesis

-bacteria in the atmosphere cycles through the system in filtration units

-in cellular respiration, carbon is released back into the atmosphere as carbon dioxide

-some carbon is stored in limestone (forming one of the largest "carbon sinks" on earth)

-largest carbon reservoir on earth= limestone

-carbon stored in the bodies of organisms as fat, oils, or other molecules may be released into the soil or air when the organism dies

-this may form deposits of coal, oil, or natural gas (fossil fuels, which increased the atmospheric carbon dioxide)

-fossil fuels store carbon left over from bodies of organisms that died millions of years ago

-they are located in the surface of earth, deep within the earth and beneath the ocean floor."