How do Earth's ecosystems resist the flow toward maximum entropy?
a. Plants and animals decompose after dying, which returns energy to an ecosystem.
b. Plants and animals store energy in ATP to prevent entropy.
c. Plants continually add energy to an ecosystem using photosynthesis, which converts the sun's energy into usable energy.
d. There are fewer animals at the top of the food chain to keep entropy in balance.

The first thermodynamic law states that energy does not create or destroy, it transforms. The total energy in an isolated system keeps invariable, but the quality of the energy (exergy) might vary.
The second thermodynamic law stated that if there is any process in a system there, the energy quality (exergy) must degrade. Any real process might only proceed in one direction that conducts to an increase in entropy.

Entropy: Thermodynamic magnitude that indicates the degree of the molecular disorder in a system.

Exergy: Measure of the maximum capacity of an energy system to produce useful work from a certain energy amount, as it balances with its environment.

Ecosystems are the biotic, physical, and chemical components of nature, acting together as disipative processes out of balance. According to the second thermodynamic low, ecosystem development should increase the degradation of energy.

Vegetable growth helps to capture solar energy and dissipate useful gradients. Many times, plants of many species are arranged in such a way that they increase together the foliar surface to optimize capture and energy degradation. Most of the plants´ energy is destined to evapotranspiration, which is the main dissipative pathway in terrestrial ecosystems

The geographical distribution of species richness is highly correlated to the annual evapotranspiration potential. This relationship between species and exergy suggests a close link between biodiversity and dissipative processes. The more exergy is available among species, the more available energy degrading paths will be. Trophic levels and food chains are based on fixed photosynthetic material and the subsequent dissipation of those gradients. There will be a higher species´diversity in places where there is more available exergy.