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Harvard Forest Data Archive
Whole-Tree Nonstructural Carbohydrate Budgets in Five Species at Harvard Forest 2014Related Publications
- Lead: Morgan Furze, Andrew Richardson, Brett Huggett, Donald Aubrecht, Claire Stolz, Mariah Carbone
- Contact: Morgan Furze
- Start date: 2014
- End date: 2014
- Status: completed
- Location: Prospect Hill Tract (Harvard Forest)
- Latitude: +42.535
- Longitude: -72.188
- Elevation: 350 meter
- Taxa: Acer rubrum (red maple), Betula papyrifera (paper birch), Fraxinus americana (white ash), Pinus strobus (white pine), Quercus rubra (red oak)
- Release date: 2018
- EML file: knb-lter-hfr.308.1
- DOI: digital object identifier
- Related links:
- Study type: short-term measurement
- Research topic: physiological ecology, population dynamics and species interactions
- LTER core area: primary production
- Keywords: carbohydrates, carbon, physiology, roots, seasonality
Despite the importance of nonstructural carbohydrates (NSC) for growth and survival in woody plants, we know little about whole-tree NSC budgets. The conventional model suggests that NSC reserves will increase over the growing season and decrease over the dormant season. Here, we compare storage in five temperate tree species to determine the size and seasonal fluctuation of whole-tree total NSC budgets as well as the contribution of individual organs.
NSC concentrations in the branches, stemwood, and roots of 24 trees were measured across twelve months. We then scaled up concentrations to the whole-tree level using allometric equations.
While whole-tree total NSC budgets followed the conventional model, sugar budgets peaked in the dormant season and starch budgets in the growing season. Seasonal depletion of total NSCs was minimal at the whole-tree level, but substantial at the organ-level, particularly in branches. Surprisingly, roots were not the major storage organ as branches stored comparable amounts of starch throughout the year, and root reserves were not used to support springtime growth.
We selected 24 mature trees for this study belonging to the following species: red oak (Quercus rubra L., n=6), white pine (Pinus strobus L., n=6), red maple (Acer rubrum, n=6), paper birch (Betula papyrifera, n=3), and white ash (Fraxinus americana L., n=3).
Each month throughout 2014, a stemwood core to the pith was collected from each tree with a standard 4.3-mm increment borer (Haglöf Company Group, Långsele, Sweden), starting at breast height on the south or southwest face of each tree with each subsequent core collected in a zigzag pattern (approximately 7.5 cm over, 7.5 cm up). In addition to a monthly stemwood core, we collected sunlit branches from the top of the canopy, which was accessed using a bucket lift. We collected coarse root cores in January, April, June, August, October, and December 2014. The first root sample was taken at 20 cm along the root from the base of the tree, and subsequent cores were taken in a zigzag pattern. Samples were kept on dry ice in the field during each collection and then stored at -80°C.
Laboratory preparations and NSC analyses
To obtain a detailed understanding of NSC storage, we subdivided organs for NSC analysis. Subdividing organs allowed for better estimates of NSC budgets since, for example, it has been shown that NSC concentrations often decline with increasing depth in the stem (Hoch et al., 2003). Samples were freeze-dried (FreeZone 2.5, Labconco, Kansas City, MO USA, and Hybrid Vacuum Pump, Vacuubrand, Wertheim, Germany) and ground (mesh 20, Thomas Scientific Wiley Mill, Swedesboro, NJ, USA; SPEX SamplePrep 1600 MiniG, Metuchen, NJ USA).
To measure sugar concentrations (adapted from Chow and Landhäusser 2004), 10 mg of previously dried and ground tissue was freeze-dried (24 hrs; FreeZone 2.5, Labconco, Kansas City, MO USA, and Hybrid Vacuum Pump, Vacuubrand, Wertheim, Germany) and then extracted with 80% hot ethanol followed by colorimetric analysis with phenol-sulfuric acid. The resulting bulk sugar extract was read at 490 nm on a microplate reader (Epoch Microplate Spectrophotometer, Bio-Tek Instruments, Winooski, VT USA) or spectrophotometer (Thermo Fischer Scientific GENESYS 10S UV-Vis, Waltham, MA, USA). Sugar concentrations (expressed as mg sugar per g dry wood) were calculated from a 1:1:1 glucose-fructose-galactose (Sigma Chemicals, St. Louis, MO USA) standard curve.
To determine starch concentrations, the remaining tissue was solubilized in NaOH and then digested with an α-amylase/amyloglucosidase digestive enzyme solution. Glucose hydrolysate was determined using a PGO-color reagent solution (Sigma Chemicals, St. Louis, MO USA) and read at 525 nm. Starch concentrations (expressed as mg starch per g dry wood) were calculated based on a glucose (Sigma Chemicals, St. Louis, MO USA) standard curve.
Allometric scaling from sugar and starch concentrations to budgets
We estimated the dry wood biomass of each subdivided organ (branch, stemwood, and root) using allometric scaling theory (Jenkins et al., 2004). We then paired the sugar and starch concentrations for each sample with the estimate of that component’s woody biomass. This was done for each sample per tree, and then the amounts were summed to estimate sugar and starch budgets (kg) for each organ.
This dataset is released to the public under Creative Commons license CC BY (Attribution). Please keep the designated contact person informed of any plans to use the dataset. Consultation or collaboration with the original investigators is strongly encouraged. Publications and data products that make use of the dataset must include proper acknowledgement.
Furze M, Richardson A, Huggett B, Aubrecht D, Stolz C, Carbone M. 2018. Whole-Tree Nonstructural Carbohydrate Budgets in Five Species at Harvard Forest 2014. Harvard Forest Data Archive: HF308.
hf308-01: NSC budgets
- year: year
- month: month
- species: species name
- tag: tree tag
- organ: woody organ
- sugar: sugar budget in woody organ (unit: kilogram / missing value: NA)
- starch: starch budget in woody organ (unit: kilogram / missing value: NA)