csrc University of Florida University of Florida

Florida AmeriFlux Publications

  1. Ryan, M.G., S.T. Gower, R.M. Hubbard, R.H. Waring, H.L. Gholz, W.P. Cropper, Jr. and S.W. Running. Woody tissue maintenance respiration of four conifers in contrasting climates. Oecologia 101: 133-140. 1995.

    This paper detailed measurements on slash pine stem respiration as part of a multi-site comparative study (with most support from an NSF to S.T. Gower). The results have been utilized to further parameterize maintenance respiration in models, as well as to help explain differences in the carbon balances coniferous stands across the U.S. The main application within our NIGEC context was to re-emphasize the relatively low overall contribution of stem respiration to the C budgets of the Florida pine plantations, but also its increasing importance as trees get larger over time.
  2. Cropper, Jr., W.P. and H.L. Gholz. 1994. Evaluating potential response mechanisms of a forest stand to fertilization and night temperature: A case study using Pinus elliottii. Ecological Bulletins (Copenhagen) 43:154-160.

    This study used the SPM to determine the role of night temperature and operational fertilization on LAI, carbon allocation to roots, and annual NPP of slash pine plantations in Florida. We demonstrated that increases in biomass increment after fertilization could be generated through several potential mechanisms. We examined (a) reallocation of 5% of the carbon translocated to fine roots, and (b) slight reduction in concentrations of internally stored carbohydrates (e.g., starch stored in coarse roots), both of which could increase LAI to observed post-fertilization levels and result in the observed stem response. We also demonstrated that the effects of cooler night temperatures, as experienced by exotic plantations in South Africa, could reduce maintenance respiration sufficiently to enable the higher LAI observed, leading to the higher stem accumulation rates there.  The results helped formulate hypotheses for subsequent research.
  3. Loescher, H.W. 1996. Non-methane hydrocarbon fluxes from Pinus elliottii and Serenoa repens comparing enclosure and above-canopy measurements. M.S. Thesis, School of Forest Resources and Conservation, University of Florida, Gainesville.

    Loescher documented significant fluxes of non-methane hydrocarbons in enclosed attached leaves/needs of slash pine and saw palmetto. He attempted to compare these rates with those made using relaxed eddy covariance from an above-canopy tower. Although unable to rationalize the observed differences due to low sample sizes, very low concentrations of many compounds, and difficulties with the REC system, this was an important study that helped pave the way for more continuous eddy covariance measurements and the development of more robust instrumentation.
  4. Cropper, Jr. W.P. 1998. Modeling the potential sensitivity of slash pine stem growth to increasing temperature and carbon dioxide. pp. 353-366 In: S. Fox and R.A.Mickler (eds.). The productivity and sustainability of southern forest ecosystems in a changing environment. Springer-Verlag, New York.

    This study also used the SPM to predict the effects of higher ambient temperatures and increased atmospheric CO2 concentrations on C accumulation by stems of slash pine plantations. This is the only paper explicitly focusing on the direct and indirect effects at the process level of potentially altered environmental conditions on slash pine plantations. The results suggest that the effects would be in opposite directions and may enable slash pine to maintain productivity and NEE largely unaffected. There are no experiments of elevated temperatures or CO2 exposure in slash pine stands to provide any direct verification of model predictions.
  5. Fang, C., J.B. Moncrieff, H.L. Gholz and K.L. Clark. 1998. Soil CO2 efflux and its spatial variation in a Florida slash pine ecosystem. Plant and Soil 205: 135-146.

    Spatial variability in soil respiration was examined by Fang as a PhD student at Edinburgh. Fang’s analysis quantified this using small chambers and short measurement periods across the forest floor of a single stand.
  6. Fang, C. and J. B. Moncrieff. 1998. An open-top chamber for measuring soil respiration and the influence of pressure difference on CO2 efflux measurement. Funct. Ecol. 12: 319-325.

    The techniques for making these types of measurements were still crude at this point and Fang designed a chamber measurement system that included the dynamic influence of air pressure.
  7. Fang, C. and J. B. Moncrieff. 1998. Simple and fast technique to measure CO2 profiles in soil. Soil Biol. Biochem. 30: 2107-2112.

    A followup to the previous methods paper that further elaborated on the soil measurements, this time for assessing vertical profiles of CO2.
  8. Gholz, H.L., W.P. Cropper, Jr. and D.N. Guerin. 1999. Phenology and productivity of saw palmetto (Serenoa repens L.) in a north Florida slash pine plantation. Can. J. For. Res. 29: 1248-1253.

    Although many measurements of the understory had been made in these ecosystems over many years, few had been published. This paper compiled the data for the most dominant and representative understory species, saw palmetto, including allometric regression equations for estimating biomass and leaf area from easily measured plant attributes. The paper also presented estimates of ANPP from palmetto under different stand conditions.
  9. Fang, C. and J. B. Moncrieff. 1999. A model for soil CO2 production and transport 1: Model development. Agric. For. Meteorol. 95: 225-236.

    A continuation of Fang’s synthesis of his Florida soil respiration spatial variability results into the development of a predictive model. This paper describes the theory and structure of a one-dimensional model (PATCIS) that simulates soil CO2 evolution. The model simulates production of CO2 from root and microbial respiration and the dominant transport process affecting the efflux rate. Soil CO2 diffusion through the heterogeneous soil structure is simulated as a function of soil temperature and soil moisture. The model also simulates litter mass and decomposition.
  10. Moncrieff, J. B. and C. Fang. 1999. A model for soil CO2 production and transport 2: Application to a Florida Pinus elliottii plantation. Agric. For. Meteorol. 95: 237-256.

    In the companion paper to the previous item, the PATCIS model is paramterized and tested in a mature slash pine plantation. Data used for model development and testing included continuous measurements of soil CO2 efflux, periodic diurnal soil gas CO2 concentration measurements, and soil temperature and moisture data. Model parameters were estimated with a multidimensional optimization method applied to half of the measured data. The goal of the optimization was to find the best set of parameter values whose associated model predictions best matched the observed soil CO2 efflux. The model did a good job of simulating measured patterns of soil CO2 efflux.
  11. Clark, K.L., H.L. Gholz, J.B. Moncrieff, F. Cropley and H.W. Loescher. 1999. Environmental controls over net exchanges of carbon dioxide from contrasting ecosystems in north Florida. Ecol. App. 9: 936-948.

    This paper first detailed C budgets along the chronosequence, including partitioning respiration into soil, heterotrophic, and above- and belowground components. The results support the early stages of the mass-balance model, demonstrating through direct measurement that ecosystems lose large amounts of C for about 2.5 years, after which NEE becomes positive once again. Mass balance rates matched those measured using eddy covariance through mid-rotation. However, older stands continue to fix C at higher rates than estimated by Gholz and Fisher. Among other possibilities, this could be because more recent stands were fertilized prior to our use (although this was not documented), which would fit results from current stands that have been fertilized during ongoing eddy covariance measurements (unpublished). Models for these forests continue to be developed.
  12. Katul, G. G., C. I. Hsieh, D. Bowling, K. Clark, N. Shurpali, A. Turnipseed, J. Albertson, K. Tu, D. Hollinger, R. Evans, B. Orfferle, D. Anderson, D. Ellsworth, C. Vogel and R. Oren.  1999. 
    Spatial variability of turbulent fluxes in the roughness sublayer of an even-aged pine forest. Boundary Layer Meteorology 93:1-28.
  13. Cropper, W. P., Jr. 2000. SPM2: A simulation model for slash pine (Pinus elliottii) forests. For. Ecol. Manage. 126: 201-212.

    Cropper made significant changes to SPM in this phase, including the addition of an explicit water flux component. The model was expanded to simulate soil water, transpiration, and interception. The previously pine-only model was also expanded to include the major understory species, saw palmetto and wax myrtle. Extensive sensitivity analyses and climate change scenario analysis was included in the paper. This version of the model is now the basis for simulations run for these ecosystems.
  14. Gholz H.L., D.A. Wedin, S.M. Smitherman, M.E. Harmon, and W.J. Parton. 2000. Long-term dynamics of pine and hardwood litter in contrasting environments: toward a global model of decomposition. Glob. Change Biol. 6: 751-765.

    The forest floor has been well documented to be the main and most dynamic pool of detrital carbon (and nutrients) in these ecosystems, both upland and wetland (in the latter as peat). This study was part of a multi-site (including all the LTER sites that then existed), 10-year field study of litter decay. Florida contributed excised slash pine fine roots for every site in the study, while red pine needles were the common leaf litter across the sites. The results confirmed earlier, more limited studies, that pine litter decomposes slowly, in fact slower than any other litter in the study, even at its native site. This highlighted its role in long-term C storage on these sites, as well as its management, including the effects of fire on litter accumulation, the effects of litter raking for mulch (in other research), and the lifecycle of C in dead fine roots in these systems.
  15. Johnson, D.W., R.B. Susfalk, H.L. Gholz, and P.J. Hanson. 2000. Simulated effects of temperature and precipitation change in several forest ecosystems. J. Hydrol. 235: 183-204. 

    This study used the Nutrient Cycling Model (NuCM) to investigate effects of increased temperature and changing precipitation (increased and decreased) on biogeochemical cycling at six forests around the country, including the Florida and Duke Forest pine NIGEC sites. Simulations of increased temperature indicated increased ET and reduced soil water fluxes. Changes in precipitation indicated disproportionately large variations in soil water flux because of the relative stability of ET with changes in precipitation. Increased temperature caused N release from forest floors at all sites. The simulations illustrated the complexity of possible responses of nutrient cycling processes to climate change. Since NuCM did not contain physiological algorithms, these results suggest that changes in temperature and precipitation could produce widely varying ecosystem-level responses through effects on biogeochemical cycling processes alone, a caution that generalizations about the relative importance of temperature versus precipitation changes are hazardous.
  16. Castro, M.S., H.L. Gholz, K.L. Clark, and P.A. Steudler. 2000. Effects of forest harvesting on soil methane fluxes in Florida slash pine plantations, Can. J. For. Res., 30, 1534-1542.

    Methane is less studied than CO2 due to difficulties in quantifying high frequency measurements at much lower concentrations. High rainfall and decreased evapotranspiration due to LAI reduction following clearcutting can cause saturated conditions in sandy surface soils of pine flatwoods. This study, largely funded by an NSF SGER, provided the only quantitative information on potential methane exchange from both disturbed (clearcut) and intact “upland” slash pine systems under a range of soil moisture conditions. Under dryer conditions methane produced deeper is oxidized in surface soils and the soils are a mild sink for atmospheric methane. The soils switch from sink to source when surface (top 15 cm) soil pore space becomes saturated, at about 65% water-filled volume. The source of methane is presumably lower organic horizons (ca. 60-80 cm depth), not oxidized when surface soil layers are also saturated. A model predicts methane fluxes in relation to soil moisture.
  17. Clark, K.L., W.P. Cropper, Jr., and H.L. Gholz. 2001. Evaluation of modeled carbon fluxes for a slash pine ecosystem: SPM2 simulations compared to eddy flux measurements. For. Sci.47: 52-59.

    Comparing eddy covariance NEE estimates to biometric measurements of C accumulation in organic matter is problematic. Florida plantations are ideal for this type of evaluation, since accumulation, at least in woody tree tissues and litter, is relatively easy to accurately assess. We concluded that total annual C accumulation in stem, coarse root and branch biomass, along with that in litter, matched well eddy covariance NEE. Although this supports the robustness of our flux measurements, there are still significant uncertainties in estimating nighttime ecosystem respiration and unmeasured biomass pools that could be important (e.g., fine roots) - the estimates could agree for wrong reasons. However, further results validate the premise that live wood and litter are together the largest and most predictable C sinks in these systems.
  18. Gholz, H.L., and K.L. Clark. 2002. Energy exchange across a chronosequence of slash pine forests in Florida. Agric. For. Meteorol. 112: 87-102.

    We addressed changes in albedo and partitioning of net radiation into soil heat fluxes, sensible heat fluxes and latent heat fluxes across three stand ages. The albedo decreased from 0.26 at the clearcut to 0.18 at closed-canopy stands. Sensible, latent and soil heat fluxes accounted for 85-90% of net radiation. S and LE were linearly related to Rnet at all sites. Seasonal differences and the effects of flooding were evaluated.  Maximum rates of ET in the summer were 0.6 mm hr-1 at all sites, with mean daily rates ranging from 2.0 to 3.3 mm day-1. Although changes in LAI and canopy structure were large, annual ET was similar and averaged 959, 951 and 1110 mm yr-1 along the chronosequence. Results suggested that energy partitioning is more sensitive to environmental fluctuations than management. 
  19. Powell, T.L. 2002. Carbon, water and energy exchange for a mature, naturally regenerated pine forest in north central Florida. M.S. Thesis, University of Florida, Gainesville, FL. 99 pp.

    Powell made eddy covariance, meteorological and ecological measurements at the naturally-regenerated ACMF pine site over a two-year period. The water and energy flux results are in Powell et al. 1995 (below) and the C results in a paper in preparation. This site is a contrast in structure to the plantations and is being managed as a model for restoration of pine flatwoods to more historic conditions. The region entered a severe multi-year drought during this study that resulted in interesting contrasts with the adjacent plantation sites. The understory at this more open site is clearly more important for exchanges of energy and C than at most plantations. This has implications for the role of ground fires that historically characterized these sites. This stand has, in fact, been prescribe-burned twice since Powell’s study ended and has become a central site for our ongoing research.
  20. Thornton, P.E., B.E. Law, H.L. Gholz, K.L. Clark, E. Falge, D.S. Ellsworth, A.H. Goldstein, R.K. Monson, D.Y. Hollinger, M. Falk, J. Chen, and J.P. Sparks. 2002. Modeling and measuring the effects of disturbance history and climate on carbon and water budgets in evergreen needleleaf forests. Agric. For. Meteorol. 113: 185-122.

    The effects of disturbance history, climate, and changes in atmospheric carbon dioxide (CO2) concentration and nitrogen deposition on C and water fluxes in seven U.S. evergreen forests were assessed using a coupled water, carbon, nitrogen model, canopy-scale flux observations, and descriptions of the vegetation type, management practices, and disturbance histories at each site. The effects of interannual climate variability, disturbance history, and vegetation ecophysiology on carbon and water fluxes and storage were integrated using Biome-BGC, with results compared to site biometric analyses and eddy covariance observations aggregated by month and year. The model produced good estimates of between-site variation in leaf area index, with mixed performance for between- and within-site variation in evapotranspiration. There is a model bias toward smaller annual carbon sinks at five sites, with a seasonal model bias toward smaller warm-season sink strength at all sites.
  21. Leclerc, M.Y., A. Karipot, T. Prabha, G. Allwine, B. Lamb, and H.L. Gholz. 2003. Impact of non-local advection on flux footprints over a tall forest canopy: a tracer flux experiment.  Agric. For. Meteorol. 115: 19-30.

    This (co-funded) project utilized a passive SF6 tracer released under contrasting stability conditions from a 200 m long, canopy-top (11m), line source at the main Florida AmeriFlux site. The tracer was tracked using both dynamic analyzers, static samplers, and eddy covariance downwind and used to test two flux footprint models, a Lagrangian simulation and an analytical solution to the diffusion equation. Both models compared favorably except during conditions where air was advected from the direction of a recent clearcut outside the estimated footprint. This was the first paper to suggest that inhomogeneities outside a tower’s footprint may cause local “abnormal” circulations near the tower.
  22. Clark K.L., H.L. Gholz, and M.S. Castro. 2004. Carbon dynamics along a chronosequence of slash pine in N. Florida. Ecol. Appl. 14: 1154-1171.

    This first synthesis used NEE tower-based eddy covariance measurements to test the empirical, chronosequence, organic matter mass-balance results of Gholz and Fisher and the Biome-BGC simulation of Thornton et al. In general the results were consistent. However, this study provided much more mechanistic understanding of controls over NEE, since it covered a range of time scales and was accompanied by high-precision mensurational and ecological measurements, as well as soil flux measurements. Results suggested an even more dynamic picture of NEE over time in the plantations as they undergo harvest and regrowth and substantiated the very large C release in the first few years after a clearcut. The range in observed NEE, characteristic of fluxes in one location over a full management cycle, was double the range reported over all global flux sites and highlighted the critical dominance of human disturbance effects on NEE.
  23. Nakane, K. and H.L. Gholz. 2004. Partitioning carbon fluxes within forest stand beneath flux tower, methodology and application. In S.-K. Hong, J.A. Lee, B.-S. Ihm, A. Farina,Y. Son, K. Eun-Shik, and J.C. Choe (eds.) Ecological Issues in a Changing World: Status, Response and Strategy. Kluwer Acad. Publ., Dordrecht, The Netherlands. pp. 65-95.

    This was a review paper produced as a summary of a symposium at the 8th International Congress of Ecology in Seoul, Korea in 2002. Papers were presented and summarized here by 8 authors from the US, Korea, Japan and Israel. Gholz summarized early results of the extrapolation of tower flux measurements to the landscape level using historical remote sensing (Landsat) imagery from co-funded NASA/LULCC and NIGEC research. Other sections focused on Amazon tropical forests, Oregon pine forests, and on various methodological aspects of quantifying forest C budgets.
  24. Powell, T.L., G. Starr, K.L. Clark, T.A. Martin, and H.L. Gholz. 2005. Ecosystem and understory water and energy exchange for a mature, naturally regenerated pine flatwoods forest in north Florida. Canadian Journal of Forest Research 35:1568-1580.

    The first energy flux measurements were reported for the new, benchmark site on the Austin Cary Memorial Forest. This is a mixed slash/longleaf pine, naturally-regenerated stand managed as a demonstration of restoration to more natural regional forest conditions, including prescribed understory fires every 3 years. In addition to regular burns, it contrasts with the plantation stands in that it has older trees (still <85 years maximum age), lower stem densities, and no regular removal of trees (clearcutting). Despite the structural differences, energy partitioning was similar to that of the plantations, as was whole system ET. The results were before the first fire was reintroduced and showed a much higher contribution to ET by the understory. The study also occurred during a 100-yr drought and is providing data to which the responses of the higher LAI plantation stands are now being contrasted.
  25. Loescher, H.W., G. Starr, T.A. Martin, M. Binford, and H.L. Gholz. 2006. The effect of local atmospheric circulations on daytime carbon dioxide flux measurements over a Pinus elliottii canopy. Journal of Applied Meteorology and Climatology 45:1127-1140.

    Whether inhomogeneities in the landscape outside flux footprints affect eddy covariance NEE at towers is very complex and difficult to directly address. Because of flat topography and relatively simple structure of the Florida stands, and high contrast created by clearcuts in comparison with intact stands, this may be the best possible location for making such determinations. We attempted to make this connection by comparing fluxes from the main tower site in relation to directional winds. Results suggest that NEE decreased as much as 16% following the clearcut, attributed to changes in turbulence dynamics at the tower, as well as changes in the CO2 background (clearcuts are strong CO2 sources).  However, the results may be confounded by intensive drought that developed during the study, which could also have led to decreased NEE. These interactions are being explored through the inclusion of leaf-level physiological data and modeling in other papers.
  26. Karipot, A., M.Y. Leclerc, G. Zhang, T.A. Martin, G. Starr, D.Y. Hollinger, J.H. McCaughey, and G.R. Hendrey. 2006. Nocturnal CO2 exchange over a tall forest canopy associated with intermittent low-level jet activity. Theoretical and Applied Climatology 85:243-248.

    This paper resulted from a collaboration between projects (TCP and NIGEC) and focused on potential novel mechanisms to explain the erratic and sometimes large efflux of CO2 from a forest to the atmosphere during otherwise stable atmospheric conditions, primarily at night. Uncertainties under these conditions are largely responsible for the remaining uncertainties in eddy covariance-based  estimates of daily and longer NEE. The study utilized mini-sodar and flux data to document and describe two nocturnal jet episodes, which are particularly common under topographic conditions as characterized by the flat Florida AmeriFlux site. During the night observed (June 24, 2004), jet activity was observed over 30% of the time, often associated with high CO2 effluxes. More work needs to determine the annual extent of nocturnal jet activity and its importance to longer-term estimates of NEE.
  27. Binford, M.W., H.L. Gholz, G. Starr, and T.A. Martin. 2006. Regional carbon dynamics in the southeastern U.S. coastal plain: Balancing land cover type, timber harvesting, fire, and environmental variation. Journal of Geophysical Research 111:D24S92-doi:10.1029/2005JD006820.

    This paper extrapolates tower and mensurational data spatially to the landscape scale within the Coastal Plain and temporally over a significant period of time (25 years). Landsat images were obtained from 1975-2000 and combined with field results to estimate annual NEE for four 15x15 km areas. Changes at the pixel level over time were attributed to forest management, mining, wildfires, and conversion to/from agriculture across wetlands, plantations, agriculture, and natural forests. Clearcuts can be accurately aged using image analysis. Clearcutting dominates annual regional NEE. The region has a background net accumulation of about 1 tC ha-1 yr-1. Wildfires and mining had strong local effects in space and time, but were not significant regionally. Other data are being used to explore NEE and in relation to land ownership changes.
  28. Zhang, G., C. Thomas, M.Y. Leclerc, A. Karipot, H.L. Gholz, M. Binford, and T. Foken. 2007. On the effect of clearcuts on turbulence structure above a forest canopy. Theoretical and Applied Climatology 88:133-137.

    This paper describes the modification of the flow structure arising from the removal of large patches of trees in a managed forest plantation near Gainesville, Florida. Using wavelet analysis of turbulence measurements taken above a forest canopy hundreds of meters downwind from the forest gap and well outside the footprint, this paper examines changes in flow characteristics and demonstrates that the presence of the nearby clearcut introduced extraneous coherent events passing by the eddy-covariance flux measurement system
  29. Yuan, W.P., S. Liu, G.S. Zhou, G.Y. Zhou, L.L. Tieszen, D. Baldocchi, C. Bernhofer, H. Gholz, A.H. Goldstein, M.L. Goulden, D.Y. Hollinger, Y. Hu, B.E. Law, P.C. Stoy, T. Vesala, and S.C. Wofsy. 2007. Deriving a light use efficiency model from eddy covariance flux data for predicting daily gross primary production across biomes. Agricultural and Forest Meteorology 143:189-207.

    This paper describes the development of a light use efficiency (LUE) daily GPP model from eddy covariance (EC) measurements. The model, called EC-LUE, is driven by only four variables: normalized difference vegetation index (NDVI), photosynthetically active radiation (PAR), air temperature, and the Bowen ratio of sensible to latent heat flux. The EC-LUE model was calibrated and validated using 24,349 daily GPP estimates derived from 28 eddy covariance flux towers from the AmeriFlux and EuroFlux networks, covering a variety of forests, grasslands and savannas. The model explained 85% and 77% of the observed variations of daily GPP for all the calibration and validation sites, respectively. A comparison with GPP calculated from the Moderate Resolution Imaging Spectroradiometer (MODIS) indicated that the EC-LUE model predicted GPP that better matched tower data across these sites. The realized LUE was predominantly controlled by moisture conditions throughout the growing season, and controlled by temperature only at the beginning and end of the growing season.
  30. Powell, T.L., H.L. Gholz, K.L. Clark, G. Starr, W.P. Cropper, Jr., and T.A. Martin. 2008. Carbon exchange of a mature, naturally-regenerated pine forest in north Florida. Global Change Biology 14:2523-2538, DOI: 10.1111/j.1365-2486.2008.01675.x.

    This paper presents a comprehensive analysis of long-term carbon balance of the Austin Cary Memorial Forest (ACMF) naturally regenerated longleaf pine / slash pine stand near Gainesville, Florida.  The analysis includes direct comparison with contemporary eddy covariance measurement taken at the intensively managed Donaldson Tract plantation stand..  The paper includes four tower-years of overstory data from ACMF, two tower-years of understory data from ACMF, and four tower-years of data from the Donaldson Tract.  In addition to carbon balance data, detailed analyses of measurement error and gap filling error are quantified and presented.
  31. Xiao, J., Q. Zhuang, D. D. Baldocchi, B. E. Law, A. D. Richardson, J. Chen, R. Oren, G. Starr, A. Noormets, S. Ma, S. B. Verma, S. Wharton, S. C. Wofsy, P. V. Bolstad, S. P. Burns, D. R. Cook, P. S. Curtis, B. G. Drake, M. Falk, M. L. Fischer, D. R. Foster, L. Gu, J. L. Hadley, D. Y. Hollinger, G. G. Katul, M. Litvak, T. A. Martin, R. Matamala, S. G. McNulty, T. P. Meyers, R. K. Monson, J. W. Munger, W. C. Oechel, K. T. Paw U, H. P. Schmid, R. L. Scott, G. Sun, A. E. Suyker, and M. S. Torn. 2008.

    Estimation of net ecosystem carbon exchange for the conterminous United States by combining MODIS and AmeriFlux data.  Agricultural and Forest Meteorology 148:1827-1847.
    A synthesis / modeling paper utilizing data from several Gainesville, Florida AmeriFlux sites. 
  32. Ollinger, S.V., A. D. Richardson, M. E. Martin, D. Y. Hollinger, S. E. Frolking, P. B. Reich, L. C. Plourde, G. G. Katul, J. W. Munger, R. Oren, M.-L. Smith, K. T. Paw U, P. V. Bolstad, B. D. Cook, M. C. Day, T. A. Martin, R. K. Monson, and H. P. Schmid. 2008.

    Canopy nitrogen, carbon assimilation, and albedo in temperate and boreal forests: Functional relations and potential climate feedbacks. Proceedings of the National Academy of Sciences of the United States of America 105 (49):19335-19340.
    Examines novel interactions among foliar nitrogen, carbon assimilation, and albedo using on-site and remotely sensed data from a range of AmeriFlux sites, including several Florida AmeriFlux locations.
  33. Mitchell, R., K. Hiers, J. O'Brien, and G. Starr. 2008.  Ecological forestry in the Southeast: Understanding the ecology of fuels. Journal of Forestry in press.

    An invited paper reviewing how understory dynamics interact with fire dynamics in pine savannahs in the southeastern U.S.  Includes prescribed fire data from our Austin Cary Memorial Forest AmeriFlux site.