1. Improving fine root sampling methods for landscape-level ecosystem studies using root anatomy and morphology Kirsten Lloyd M.S. Candidate Complex Systems Research Center University of New Hampshire, USA

2. In the White Mountain National Forest, we know: 1) Foliar chemistry (e.g., nitrogen content) is related to forest productivity. 2) Hyperspectral methods allow remote-sensing of canopy chemistry. However, theoretical links from aboveground to belowground processes have not been established due to methodological difficulties. My research is an initial step to include belowground processes into an on-going campaign of landscape-level ecosystem studies.

3. Location of Bartlett Experimental Forest (BEF) in the White Mountain National Forest, New Hampshire, USA 10 km Bartlett Experimental Forest AVIRIS remote sensing scenes Northeastern U.S. White Mountain National Forest, NH 360,000 ha

4. A Landscape-Level Field Study in the White Mountain National Forest Mapping andAnalysis of Productivity and Biogeochemical Cycling Mapping and Analysis of Productivity and Biogeochemical Cycling Canopy Chemistry Remote Sensing Field Work Modeling & Data Synthesis Productivity N Cycling, Nitrification Soil Mineralogy Stream Chemistry MAPBGC LeafChemistry

5. VEGETATION R EMOTE S ENSING OF F OLIAR N W h i t e M o u n t a i n N a t i o n a l F o r e s t AVIRIS EO-1 Hyperion 0.50 1.00 1.50 2.00 2.50 3.00 0.501.001.502.002.503.00 Field Measured %N AVIRIS Predicted %N R 2 = 0.84 AVIRIS Foliar N Predicted (PLS) vs. Observed

6. Hardwood Conifer Forest Productivity and Nitrogen Status 0 200 400 600 800 1000 0.51.01.52.02.53.0 ANPP (g m -2 yr ) Foliar N Concentration (%) Aboveground NPP Belowground Production not yet known. Smith et al. 2002 Ecol. App.

7. Using Canopy N to Drive Ecosystem Models Predicted NPP Using AVIRIS Bartlett Experimental Forest, NH < 700 6007008009001000>1300 (g m -2 yr -1 ) Kilometers 0 1 Old Sugar Maple on deep till soils (540 m) Upper elevation Spruce on shallow bedrock (800 m) Eastern Hemlock (300 m) Mixed White Pine on sandy outwash (220 m) Cut + NPK Fertilizer, 1963 N

8. Root Chemistry ?? QUESTION: Are foliar and root chemistry related? Canopy Chemistry Productivity Cycling, Nitrification Mineralogy Chemistry LeafChemistry

9. PROBLEM: In order to directly compare foliar and root chemistry, we must be able to sample roots similarly to foliage (by species). HOW CAN WE IMPROVE ROOT SAMPLING?  Use secondary xylem anatomy to identify woody roots  Develop morphological parameters by species (or genus) for fine roots

10. Methods Sampling: Roots were collected from soil pits dug at 9 plots within BEF. The plots represent a gradient of site fertility/productivity and species compositions. The roots of six angiosperm species (Acer rubrum L., Acer saccharum Marsh., Betula alleghaniensis Britt., Betula papyrifera Marsh. Fagus grandifolia Ehrh., and Fraxinus americana L.) and three gymnosperm species (Picea rubens Sarg., Pinus stobus L., and Tsuga canadensis (L.)Carr.) were sampled. Anatomy: Secondary roots approximately 2 to10 mm in diameter were hand- sectioned on transverse and longitudinal planes. Unstained, fresh sections were examined using light microscopy. Roots were identified based on diagnostic traits of secondary xylem. Images were acquired using an Olympus Vanox microscope (Model BHT), Olympus U-PMTVC camera and ImagePro 4.0 image processing software. Morphology: Ephemeral segments of identified roots were photographed on a 1-mm grid.

11. Results: Gymnosperms SpeciesResin ducts Cross-field pittingMorphology Picea rubens presentpiceoidCenococcum; very fine Pinus strobus presentfenestriformroot hairs; dichotomous branching Tsuga canadensis absent 1 cupressoidperpendicular branching 1 may have central axial resin canal in primary xylem

12. Results: Angiosperms SpeciesPerforation plates Vessel pitting Vessel thickenings Morphology Acer sp.simplealternatespiral“beaded” short roots Betula sp.scalariformalternate, minute absentfine, smooth periderm Fagus grandifolia simpleopposite or scalariform absentwide rays (cross-section) Fraxinus americana simplealternateabsentlight-colored periderm

13. Conclusions  Woody roots can be identified using secondary xylem anatomy.  Ephemeral root morphology can be used to identify fine roots for sampling.

14. Project direction StatusTask Complete Characterize morphological traits of fine roots to allow genus- or species-level identification. Complete Sample foliage and ephemeral roots from tree species at the Bartlett Experimental Forest. In progress Analyze chemistry (e.g., carbon and nitrogen) to determine trends among foliage and roots. FutureEvaluate the potential for relationships among foliar and fine root tissue chemistry to be extended spatially using hyperspectral remote-sensing estimates of forest canopy chemistry.

15. References Smith, M.L., et al. 2002. Ecological Applications 12, 1286 – 1302. Ollinger, S.V., et al. 2002. Ecology 83, 339-355. Research support provided by the New Hampshire Space Grant Consortium graduate fellowship program.