McAlpine was a lecturer in biology at the University of Melbourne from 1884, and, with his appointment to the Victorian Department of Agriculture from 1890 to 1911, became the British Empire's first professional plant pathologist.

McAlpine graduated from the University of London in 1873, where he attended lectures given by such luminaries as Thomas Henry Huxley (biology), William Turner Thiselton-Dyer (botany), Archibald Geikie (geology), and Robert Etheridge (paleontology).

[4] McAlpine had a long friendship with David Orme Masson, Professor of Chemistry at the University of Melbourne known for his work on the explosive compound nitroglycerine.

[1] As vegetable pathologist, McAlpine was tasked with determining the cause of bitter pit, a once economically devastating fungal disease of apples in Australia.

The first lecture was given by Lilian Fraser at the 2nd National Conference held in Brisbane 12–14 May 1976,[7] was titled "Diseases of Citrus Trees in Australia - the First Hundred Years".

[10] Fungus species named in his honour include Amanitopsis mcalpineana Cleland & Cheel (1914),[11] and Hydnangium mcalpinei Rodw.