Final answer:
The treeline generally descends in elevation from the equator toward the poles due to decreasing temperatures with increasing latitudes and altitudes, affecting tree growth sustainability.
Step-by-step explanation:
The elevation of the treeline tends to decrease as one moves from the equator toward the poles. This occurs because the temperature generally decreases with both higher altitudes and higher latitudes. Near the equator, mountains can have tropical climates at lower elevations and progressively colder climates as one ascends, eventually reaching a point where the environment can no longer support tree growth, known as the treeline.
As you travel towards the poles, this point of unsustainability for trees occurs at lower altitudes due to the overall cooler temperatures. Factors like temperature, which falls from lower to higher altitudes, and the presence of different climate zones, or biomes, contribute to these gradual changes, mirroring the effects seen when moving towards higher latitudes.