TY - JOUR
T1 - Forest demography and biomass accumulation rates are associated with transient mean tree size vs. density scaling relations
AU - Yu, Kailiang
AU - Chen, Han Y.H.
AU - Gessler, Arthur
AU - Pugh, Thomas A.M.
AU - Searle, Eric B.
AU - Allen, Robert B.
AU - Pretzsch, Hans
AU - Ciais, Philippe
AU - Phillips, Oliver L.
AU - Brienen, Roel J.W.
AU - Chu, Chengjin
AU - Xie, Shubin
AU - Ballantyne, Ashley P.
N1 - Publisher Copyright:
© The Author(s) 2024. Published by Oxford University Press on behalf of National Academy of Sciences. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
PY - 2024/2/1
Y1 - 2024/2/1
N2 - Linking individual and stand-level dynamics during forest development reveals a scaling relationship between mean tree size and tree density in forest stands, which integrates forest structure and function. However, the nature of this so-called scaling law and its variation across broad spatial scales remain unquantified, and its linkage with forest demographic processes and carbon dynamics remains elusive. In this study, we develop a theoretical framework and compile a broad-scale dataset of long-term sample forest stands (n = 1,433) from largely undisturbed forests to examine the association of temporal mean tree size vs. density scaling trajectories (slopes) with biomass accumulation rates and the sensitivity of scaling slopes to environmental and demographic drivers. The results empirically demonstrate a large variation of scaling slopes, ranging from −4 to −0.2, across forest stands in tropical, temperate, and boreal forest biomes. Steeper scaling slopes are associated with higher rates of biomass accumulation, resulting from a lower offset of forest growth by biomass loss from mortality. In North America, scaling slopes are positively correlated with forest stand age and rainfall seasonality, thus suggesting a higher rate of biomass accumulation in younger forests with lower rainfall seasonality. These results demonstrate the strong association of the transient mean tree size vs. density scaling trajectories with forest demography and biomass accumulation rates, thus highlighting the potential of leveraging forest structure properties to predict forest demography, carbon fluxes, and dynamics at broad spatial scales.
AB - Linking individual and stand-level dynamics during forest development reveals a scaling relationship between mean tree size and tree density in forest stands, which integrates forest structure and function. However, the nature of this so-called scaling law and its variation across broad spatial scales remain unquantified, and its linkage with forest demographic processes and carbon dynamics remains elusive. In this study, we develop a theoretical framework and compile a broad-scale dataset of long-term sample forest stands (n = 1,433) from largely undisturbed forests to examine the association of temporal mean tree size vs. density scaling trajectories (slopes) with biomass accumulation rates and the sensitivity of scaling slopes to environmental and demographic drivers. The results empirically demonstrate a large variation of scaling slopes, ranging from −4 to −0.2, across forest stands in tropical, temperate, and boreal forest biomes. Steeper scaling slopes are associated with higher rates of biomass accumulation, resulting from a lower offset of forest growth by biomass loss from mortality. In North America, scaling slopes are positively correlated with forest stand age and rainfall seasonality, thus suggesting a higher rate of biomass accumulation in younger forests with lower rainfall seasonality. These results demonstrate the strong association of the transient mean tree size vs. density scaling trajectories with forest demography and biomass accumulation rates, thus highlighting the potential of leveraging forest structure properties to predict forest demography, carbon fluxes, and dynamics at broad spatial scales.
KW - biomass accumulation rates
KW - forest demography
KW - forest structure and function
KW - mean tree size vs. density scaling trajectory
UR - http://www.scopus.com/inward/record.url?scp=85186103139&partnerID=8YFLogxK
U2 - 10.1093/pnasnexus/pgae008
DO - 10.1093/pnasnexus/pgae008
M3 - Article
C2 - 38390215
AN - SCOPUS:85186103139
VL - 3
SP - pgae008
JO - PNAS Nexus
JF - PNAS Nexus
IS - 2
M1 - pgae008
ER -