Harvard Forest CNDD in ECM species 2019

Published: 25 February 2022| Version 4 | DOI: 10.17632/ws3cdn28n8.4
Fiona Jevon


To test the strength of density dependence and whether it affects seedling community diversity in a temperate forest, we tracked the survival of seedlings of three ectomycorrhizal-associated species experimentally planted beneath conspecific and heterospecific adults. We compared these results to evidence of CNDD from observed sapling survival patterns of 28 species over approximately 8 years in a 35-hectare forest plot in Massachusetts, USA. We then used the observational sapling survival to compare species-specific estimates of CNDD to mycorrhizal association, shade tolerance, and local abundance. Experimental seedling survival was always lower under conspecific adults, which increased seedling community diversity in one of six treatments. In our observational sapling analysis, we found evidence of significant, negative CNDD in 23 of 28 species. Contrary to our expectations, ectomycorrhizal-associated species generally exhibited stronger (e.g. more negative) CNDD than arbuscular mycorrhizal- associated species. CNDD was also stronger in more shade tolerant species but was not associated with local abundance.



Forest Ecology