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Article
Fine root production estimates and belowground carbon allocation in forest ecosystems
Ecology (1992)
  • James W. Raich, Woods Hole Oceanographic Institution
  • Knute J. Nadelhoffer, Woods Hole Oceanographic Institution
Abstract
We compared published estimates of net fine root production (FRP) in forest
sites to litterfall and aboveground net primary production (ANPP) to test whether annual
rates of fine root and aboveground production vary together at global scales. We also
compared FRP estimates to theoretical upper limits as defined by our previously published
relationship between total root allocation (TRA, carbon allocated to FRP plus live-root
respiration) and litterfall. Estimates of the carbon content of FRP in the total data set
ranged from 25 to 820 g m-2 yr-t and were not correlated with annual litterfall or ANPP.
Different methods used for estimating fine root production, however, showed contrasting
results. Estimates derived using either sums of seasonal changes in fine root biomass
("Sequential Core" method) or differences between annual maximum and minimum fine
root biomass ("Maximum - Minimum" method) were not correlated with either litterfall
or ANPP. Sequential Core estimates were often high relative to predicted TRA values,
whereas Maximum - Minimum estimates were generally < 50% of TRA. The small number
of FRP estimates derived from root growth into root-free cores ("Ingrowth Core" method)
were not correlated with measures of aboveground production but were all well below
predicted TRA values. In contrast to results of other methods, FRP estimates derived using
ecosystem N budgets ("N Budget" method) were positively correlated with both litterfall
and ANPP. Comparing FRP estimates based on N budgets with previous results of forest
soil C budgets suggested that annual fine root production increases with aboveground
production and that ' 1/3 of TRA is used for production of fine roots.
Keywords
  • belowground production,
  • carbon budgets,
  • fine roots,
  • forests,
  • net primary production,
  • nitrogen budgets,
  • root production
Publication Date
1992
DOI
10.2307/1940664
Publisher Statement
Copyright 1992 Ecological Society of America. Nadelhoffer, Knute J., and James W. Raich. "Fine root production estimates and belowground carbon allocation in forest ecosystems." Ecology 73, no. 4 (1992): 1139-1147.
Citation Information
James W. Raich and Knute J. Nadelhoffer. "Fine root production estimates and belowground carbon allocation in forest ecosystems" Ecology Vol. 73 Iss. 4 (1992) p. 1139 - 1147
Available at: http://works.bepress.com/jim_raich/16/