The first famous natural scientist to determine how plants change with altitude on tall mountains was Alexander Von Humboldt and Aime Bonpland when climbing some very high volcanoes in South America like Chimborazo at well ove 20,000 feet high and they observed that different plants grow at different altitudes as altitude increases so that as the mountain was ascended the new environments of temperature, moisture,etc would become abiotic for the lower plants but acceptable for the higher elevation plants. In these cases in South America, the lower elevations had very warm temperatures and high humidity so would grow tropical plants with probably large leaves like palm trees etc. On the other hand at high elevations the temperature would be significantly decreased and probably humidity decreased too so only rugged plants like say lichens could grow. At intermediate elevations, most likely say pine trees could grow as I know they do at moderate elevations in Honduras for example.
Answer:
approximately 4.5 billion years ago
Explanation:
