This photo is very reliable because it shows all the different layers of mountain vegetation and some of the common plants that grow on these layers and that can grow on these layers.
This website provides some basic information on Mountain vegetation. It states that Mountain vegetation is made up of other biomes (Grasslands, Coniferous forest and Tundra) and describes how mountains are formed.
This prezi presentation is very informative and good if you want a brief overview of Mountain vegetation. It gives you a glossary on words that are used in the prezi, a brief overview, plants, animals, landscape/habitats and influence of humans. It also includes a bibliography.
This website is very useful and reliable because it gives an insight on the mountain ecosystem i.e plants, animals, habitats, environments, etc. It is very informative stating the Origin, Environment, Biota (Flora & Fauna) and influence of Population.