Which of the following factors has the greatest effect on the rate of chemical cycling within an ecosystem?

Recall the Arrhenius equation, which shows the relationship between temperature and reaction rate: $k=A{e}^{-\frac{Ea}{RT}}$, where $k$ is the rate constant, $A$ is the pre-exponential factor, $Ea$ is the activation energy, $R$ is the gas constant, and $T$ is the temperature in Kelvin.

Consider how an increase in temperature generally increases the rate of chemical reactions by providing more energy to overcome activation barriers, thus speeding up chemical cycling.