We conducted a field investigation and evaluation of 13C natural abundance to determine the growth habit and propagation strategy of Acer catalpifolium Rehd., a tree species native to China that is highly endangered. The results showed that A. catalpifolium is a K-selected strategist and pioneer species. Its narrow ecological range limits its geographical distribution, and poor fecundity limits its population size. The analysis of 13C natural abundance showed that A. catalpifolium does not use organic matter for reproduction when its stand volume is less than 1.08 × 106 cm3 or it is less than 18.6 m tall, but it does use this strategy when it has a sufficient 1.08 × 106 cm3 stand volume or more or is taller than 18.6 m. If environmental conditions are not conducive (e.g., severe human disturbance, cliff edges, or fierce interspecific competition) to the continued growth of the tree, A. catalpifolium may allocate organic matter for reproduction. Human disturbance seems to promote the population expansion of A. catalpifolium. We provide our suggestions for the promotion and protection of A. catalpifolium as a species. © 2020 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.