Academic Commons


Demography of Symbiotic Nitrogen-Fixing Trees Explains Their Rarity and Successional Decline in Temperate Forests in the United States

Liao, Wenying; Menge, Duncan N. L.

Symbiotic nitrogen (N) fixation is the major N input to many ecosystems. Although temperate forests are commonly N limited, symbiotic N-fixing trees (“N fixers”) are rare and decline in abundance as succession proceeds–a challenging paradox that remains unexplained. Understanding demographic processes that underlie N fixers’ rarity and successional decline would provide a proximate answer to the paradox. Do N fixers grow slower, die more frequently, or recruit less in temperate forests? We quantified demographic rates of N-fixing and non-fixing trees across succession using U.S. forest inventory data. We used an individual-based model to evaluate the relative contribution of each demographic process to community dynamics. Compared to non-fixers, N fixers had lower growth rates, higher mortality rates, and lower recruitment rates throughout succession. The mortality effect contributed more than the growth effect to N fixers’ successional decline. Canopy and understory N fixers experienced these demographic disadvantages, indicating that factors in addition to light limitation likely contribute to N fixers’ successional decline. We show that the rarity and successional decline of N-fixing trees in temperate forests is due more to their survival disadvantage than their growth disadvantage, and a recruitment disadvantage might also play a large role.


Also Published In

More About This Work

Academic Units
Ecology, Evolution, and Environmental Biology
Public Library of Science
Published Here
January 18, 2017
Academic Commons provides global access to research and scholarship produced at Columbia University, Barnard College, Teachers College, Union Theological Seminary and Jewish Theological Seminary. Academic Commons is managed by the Columbia University Libraries.