ABSTRACT
This chapter analyzes the rise and decline of life zone theory (LZT), an effort within a nascent North American ecological science to explain and map the geographic distribution of species on a continental scale. The introduction, spread, and eventual abandonment of LZT occurred in the decades straddling the turn of the twentieth century when ecology was emerging from its roots in the activities of amateur naturalists and taking its modern form as an organized scientific field. The chapter focuses on two North American scientists, C. Hart Merriam and Joseph Grinnell, who personified this transition and played key roles in the promotion of life zones. The problem of identifying, delineating, and explaining geographical units of flora and fauna was central in the early history of ecology. The concept of boundary work provides an additional tool for analyzing the early history of ecology.
