Example of plant communities around the Transverse Ranges 
- One of the first attempts at defining plant communities was by C. Hart Merriam, who believed that temperature ruled all. Thus his communities in desert mountains were lower desert, higher desert, transition, Canadian, Hudsonian, Arctic-Alpine, corresponding exactly to shifts in latitude north. Merriam's names for those communities were eventually mostly discarded, since a high-elevation southern desert mountain has almost no resemblance to the plant communities in the Arctic except for temperature.