Leslie Rensselaer Holdridge
September 29, 1907
|Died||June 19, 1999 (aged 91)|
|Alma mater||H. B.S. in
University of Maine, 1931, postgrad., 1931-32|
M.S. in Ecology, University of Michigan, 1946, Ph.D., 1947.
|Institutions||Costa Rica Institute of Technology|
Leslie Ransselaer Holdridge (September 29, 1907 – June 19, 1999) was an American botanist and climatologist. He was the father of composer Lee Holdridge as well as the father of Leslie A. Holdridge, Lorena Holdridge, Marbella Holdridge, Marly Holdridge, Marisela Holdridge, Thania Holdridge, John Holdridge, Ida Holdridge, Reuseland Holdridge, Leythy J. Holdridge and youngest son Gregory Holdridge whom he fathered with Costa Rican Clara Luz Melendez.
In his famous 1947 paper,  he defined "life zones" using three indicators:
- Mean annual biotemperature (average temperature, after data values below 0 °C or above 30 °C have been eliminated)
- Total annual precipitation
- The ratio of mean annual potential evapotranspiration to mean total annual precipitation. 
- Holdridge, L.R. (1947). "Determination of world plant formations from simple climatic data". Science. 105 (2727): 367–8. Bibcode: 1947Sci...105..367H. doi: 10.1126/science.105.2727.367. PMID 17800882.
- Steere, W. (1945). The Cinchona-Bark Industry of South America. The Scientific Monthly, 61(2), 114-126. Retrieved from http://www.jstor.org/stable/18623