Carbon dioxide fluxes in coastal Douglas-fir stands at different stages of development after clearcut harvesting

Abstract Forests play a significant role in the global carbon (C) cycle. Variability in weather, species, stand age, and current and past disturbances are some of the factors that control stand-level C dynamics. This study examines the relative roles of stand age and associated structural characteristics and weather variability on the exchange of carbon dioxide between the atmosphere and three different coastal Douglas-fir stands at different stages of development after clearcut harvesting. The eddy covariance technique was used to measure carbon dioxide fluxes and a portable soil chamber system was used to measure soil respiration in the three stands located within 50 km of each other on the east coast of Vancouver Island, British Columbia, Canada. In 2002, the recently clearcut harvested stand (HDF00) was a large C source, the pole/sapling aged stand (HDF88) was a moderate C source, and the rotation-aged stand (DF49) was a moderate C sink (net ecosystem production of −606, −133, and 254 g C m −2  year −1 , respectively). Annual gross ecosystem production and ecosystem respiration also increased with increasing stand age. Differences in stand structural characteristics such as species composition and phenology were important in determining the timing and magnitude of maximum gross ecosystem production and net ecosystem production through the year. Both soil and ecosystem respiration were exponentially related to soil temperature in each stand with total ecosystem respiration differing more among stands than soil respiration. Between 1998 and 2003, annual net ecosystem production ranged from 254 to 424 g C m −2  year −1 over 6 years for DF49, from −623 to −564 g C m −2  year −1 over 3 years for HDF00, and from −154 to −133 g C m −2  year −1 over 2 years for HDF88. Interannual variations in C exchange of the oldest, most structurally stable stand (DF49) were related to variations in spring weather while the rapid growth of understory and pioneer species influenced variations in HDF00. The differences in net ecosystem production among stands (maximum of 1000 g C m −2  year −1 between the oldest and youngest stands) were an order of magnitude greater than the differences among years within a stand and emphasized the importance of age-related differences in stand structure on C exchange processes.

[1]  Nathan Phillips,et al.  Biophysical controls of carbon flows in three successional Douglas-fir stands based on eddy-covariance measurements. , 2002, Tree physiology.

[2]  W. Oechel,et al.  Environmental controls over carbon dioxide and water vapor exchange of terrestrial vegetation , 2002 .

[3]  T. Black,et al.  Annual and seasonal variability of sensible and latent heat fluxes above a coastal Douglas-fir forest, British Columbia, Canada , 2003 .

[4]  Scott D. Miller,et al.  Effect of stand age on whole ecosystem CO2 exchange in the Canadian boreal forest , 2003 .

[5]  E. Humphreys.  Net ecosystem production of three coastal Douglas-fir stands at different stages of development after harvesting , 2004 .

[6]  T. A. Black,et al.  Measuring forest floor CO2 fluxes in a Douglas-fir forest , 2002 .

[7]  Werner A. Kurz,et al.  A 70-YEAR RETROSPECTIVE ANALYSIS OF CARBON FLUXES IN THE CANADIAN FOREST SECTOR , 1999 .

[8]  Denis Loustau,et al.  The annual carbon budget of a French pine forest (Pinus pinaster) following harvest , 2003 .

[9]  M. G. Ryan,et al.  Evidence that hydraulic conductance limits photosynthesis in old Pinus ponderosa trees. , 1999, Tree physiology.

[10]  N. Jensen,et al.  Two years of continuous CO2 eddy-flux measurements over a Danish beech forest , 2001 .

[11]  Stan D. Wullschleger,et al.  Biochemical Limitations to Carbon Assimilation in C3 Plants—A Retrospective Analysis of the A/Ci Curves from 109 Species , 1993 .

[12]  T. A. Black,et al.  Changes in net ecosystem productivity with forest age following clearcutting of a coastal Douglas-fir forest: testing a mathematical model with eddy covariance measurements along a forest chronosequence. , 2007, Tree physiology.

[13]  David L. Spittlehouse,et al.  Water Availability, Climate Change and the Growth of Douglas-Fir in the Georgia Basin , 2003 .

[14]  W. Rawls,et al.  Estimating generalized soil-water characteristics from texture , 1986 .

[15]  T. A. Black,et al.  Net Carbon Exchange of three Boreal Forests during a Drought , 2004 .

[16]  Kyaw Tha Paw U,et al.  Carbon Dioxide Exchange Between an Old-growth Forest and the Atmosphere , 2004, Ecosystems.

[17]  K. Morgenstern,et al.  Net ecosystem production of a Douglas‐fir stand for 3 years following clearcut harvesting , 2005 .

[18]  Frank Berninger,et al.  Carbon balance of different aged Scots pine forests in Southern Finland , 2004 .

[19]  Wenjun Chen,et al.  Increased carbon sequestration by a boreal deciduous forest in years with a warm spring , 2000 .

[20]  Dennis Baldocchi,et al.  On Measuring Net Ecosystem Carbon Exchange Over Tall Vegetation on Complex Terrain , 2000, Boundary-Layer Meteorology.

[21]  Arnaud Carrara,et al.  Net ecosystem CO2 exchange of mixed forest in Belgium over 5 years , 2003 .

[22]  T. Black,et al.  Inter-annual variability in the leaf area index of a boreal aspen-hazelnut forest in relation to net ecosystem production , 2004 .

[23]  Dennis D. Baldocchi,et al.  Seasonal differences in carbon and water vapor exchange in young and old-growth ponderosa pine ecosystems , 2002 .

[24]  T. A. Black,et al.  Ecophysiological controls on the carbon balances of three southern boreal forests , 2003 .

[25]  Xuhui Lee,et al.  On micrometeorological observations of surface-air exchange over tall vegetation , 1998 .

[26]  T. A. Black,et al.  Sensitivity and uncertainty of the carbon balance of a Pacific Northwest Douglas-fir forest during an El Niño/La Niña cycle , 2004 .

[27]  B. Amiro,et al.  Paired‐tower measurements of carbon and energy fluxes following disturbance in the boreal forest , 2001 .

[28]  Corinna Rebmann,et al.  Productivity of forests in the Eurosiberian boreal region and their potential to act as a carbon sink –‐ a synthesis , 1999 .

[29]  Tareq Hussein,et al.  Fluxes of carbon dioxide and water vapour over Scots pine forest and clearing , 2002 .

[30]  Peter E. Thornton,et al.  Modeling and measuring the effects of disturbance history and climate on carbon and water budgets in evergreen needleleaf forests , 2002 .

[31]  J. Chen.  Optically-based methods for measuring seasonal variation of leaf area index in boreal conifer stands , 1996 .

[32]  Carbon storage and fluxes in ponderosa pine forests at different developmental stages , 2001 .

[33]  Hugh J. Barclay,et al.  Relationship of readings from the LI-COR canopy analyzer to total one-sided leaf area index and stand structure in immature Douglas-fir , 2000 .

[34]  Eric A. Davidson,et al.  Spatial and temporal variability in forest–atmosphere CO2 exchange , 2004 .

[35]  Henry L. Gholz,et al.  CARBON DYNAMICS ALONG A CHRONOSEQUENCE OF SLASH PINE PLANTATIONS IN NORTH FLORIDA , 2004 .

[36]  S. Wofsy,et al.  Factors Controlling Long- and Short-Term Sequestration of Atmospheric CO2 in a Mid-latitude Forest , 2001, Science.