How can montane vegetation be best studied?

Correct answer: By order of altitude

The direct answer is D: by order of altitude. Montane means mountain-related. On a mountain, height changes temperature, moisture, slope conditions and sometimes snow cover. Because these conditions change from the foot upward, plant communities also change in belts. A proper study therefore begins at lower altitude and proceeds toward higher altitude, comparing vegetation at each level. A, sea depth, concerns marine environments and does not describe mountain belts. B, markets, is a human-economic arrangement, not a vegetation factor. C, languages, is cultural geography and has no direct basis for classifying plants. D is correct because altitude creates the main sequence. Exam cue: mountain vegetation is read vertically, from low to high.