which living organisms is crucial to ensuring the nitrogen gas from the air becomes available as a nutrient for living things?

Bacterias

Explanation:

Rhibozium is a famous bacteria which is usually associate with the bean. That's why beans have so much protein in their composition, altough they are plants:  the Rhibozium fixes Nytrogen which is used for assembling proteins.

There are also other bacterias which are important for the process, we call them nitrobacter. They're function is, bassicaly, to converts the fixed Nytrogen (in form of NH4+) into a more available form for plants.

explanation:

plz give me the characteristics.

answer: decrease

a limiting factor is the one which decrease the abundance, distribution and causes extinction of the population of species in a ecosystem. here, predators including hawks, owls and snakes are the limiting factor for the population of mexican free tailed bat.   although bats are nocturnal animals as they forge for food at night these predators also may remain active during night which can decrease the population of the mexican free-tailed bats. also, these bats eat only one type of insects that are moths. the food can also be a limiting factor as all 400 members are dependent upon same type of food needs that are moths. the decrease in the moth population can cause decrease in population size of the mexican free-tailed bats.

therefore, the scenarios will most likely to decrease the population size of the mexican free-tailed bats.