Food web stability is most dependent on the number of connections among species.
You're correct because when birds hit their max altitude it's harder to breathe and to minimize the time of there flight they store immense amounts of oxygen in their lungs.
I think so it is molecules
The sum of and interaction between all living beings.<span>The biosphere is the global ecological system integrating all living organisms and their relationships. The interaction with the elements of the lithosphere, hydrosphere, and atmosphere is also included. The biosphere, we know today, has evolved for 3.5 billion years.</span>The biosphere covers most of the planet and stretches from the deep ocean to the highest mountain tops. Microorganisms also live deep beneath the surface of the Earth.The biosphere is divided into different biomes. Each of these consist of species that are related in their ability to cope with a specific climate. Biomes are separated by latitude. Arctic and Antacrtic biomes are vastly different from tropical biomes, for example.<span>Climate change influences the distribution of these biomes and to some extent displaces them.</span><span>The biosphere is an important reservoir in the carbon cycle and has a very significant impact on climate through release and removal of CO2 from the atmosphere.</span>