Predicting tree biomass growth in the temperate-boreal ecotone: is tree size, age, competition or climate response most important?

Global Change Biology
By: , and 

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Abstract

As global temperatures rise, variation in annual climate is also changing, with unknown consequences for forest biomes. Growing forests have the ability to capture atmospheric CO2and thereby slow rising CO2 concentrations. Forests’ ongoing ability to sequester C depends on how tree communities respond to changes in climate variation. Much of what we know about tree and forest response to climate variation comes from tree-ring records. Yet typical tree-ring datasets and models do not capture the diversity of climate responses that exist within and among trees and species. We address this issue using a model that estimates individual tree response to climate variables while accounting for variation in individuals’ size, age, competitive status, and spatially structured latent covariates. Our model allows for inference about variance within and among species. We quantify how variables influence aboveground biomass growth of individual trees from a representative sample of 15 northern or southern tree species growing in a transition zone between boreal and temperate biomes. Individual trees varied in their growth response to fluctuating mean annual temperature and summer moisture stress. The variation among individuals within a species was wider than mean differences among species. The effects of mean temperature and summer moisture stress interacted, such that warm years produced positive responses to summer moisture availability and cool years produced negative responses. As climate models project significant increases in annual temperatures, growth of species likeAcer saccharum, Quercus rubra, and Picea glauca will vary more in response to summer moisture stress than in the past. The magnitude of biomass growth variation in response to annual climate was 92–95% smaller than responses to tree size and age. This means that measuring or predicting the physical structure of current and future forests could tell us more about future C dynamics than growth responses related to climate change alone.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Predicting tree biomass growth in the temperate-boreal ecotone: is tree size, age, competition or climate response most important?
Series title Global Change Biology
DOI 10.1111/gcb.13208
Volume 22
Issue 6
Year Published 2016
Language English
Publisher Wiley
Contributing office(s) Southwest Biological Science Center
Description 14 p.
First page 2138
Last page 2151
Country United States
State Minnesota
Other Geospatial Superior National Forest
Online Only (Y/N) N
Additional Online Files (Y/N) N