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Researchers in the Multiple Element Limitation in Northern Hardwood Ecosystems (MELNHE) project are studying N and P acquisition and limitation through a series of nutrient manipulations in northern hardwood forests. This project is supported by the National Science Foundation, and builds upon the Northern Hardwood Forest Calcium Cycling Project, which established our sites at Bartlett. The project has also been called the Shoestring Project, during the period of unfunded effort between major research grants.

Although temperate forests are generally thought of as N-limited, resource optimization theory predicts that ecosystem productivity should be co-limited by multiple nutrients. These ideas are represented in the Multi-Element Limitation (MEL) model (Rastetter et al. 2012). To test the patterns of resource limitation predicted by MEL, we are conducting nutrient manipulations in three study sites in the White Mountain National Forest in New Hampshire: Bartlett Experimental Forest, Hubbard Brook Experimental Forest, and Jeffers Brook.
At Bartlett, we have three replicate stands of three ages, young (clearcut 1985-1990), mid-aged (clearcut 1975-1978), and mature (clearcut 1883-1890). At Hubbard Brook and Jeffers Brook, we have stands that correspond to the mid-aged and mature stands at Bartlett, for 4 more stands. Each of the 13 stands has four 1/4 ha (50 m x 50 m) treatment plots, treated annually each spring beginning in 2011, with N (30 kg N/ha/yr as NH4NO3), P (10 kg P/ha/yr as NaH2PO4), N+P, or nothing (an untreated control). Five stands also have a Ca treatment plot (1150 kg Ca/ha in the form of CaSiO3).
We are monitoring stem diameter, leaf litter production and nutrient flux, foliar chemistry and nutrient resorption, canopy reflectance, sap flow, root biomass and production, mycorrhizal associations, soil respiration, soil N and P availability, N mineralization, soil phosphatase activity, soil carbon and nitrogen, and bird activity. See highlights below for our results to date!

This material is based upon work supported by the National Science Foundation under Collaborative Grant Nos. #DEB- 0949324 (ESF), 0949420 (MBL), 0949317 (Miami U), 0949854 (Cornell) and 0949550 (U Mich), and supplements thereto, with cooperation from the Northeastern States Research Cooperative, the LTER site grant to Hubbard Brook, the Hubbard Brook Research Foundation, and the McIntire-Stennis Cooperative Forestry Research Act. Any opinions, findings, conclusions, or recommendations expressed in the material are those of the author(s) and do not necessarily reflect the views of any of these agencies.

MELNHE is led by 3 principal investigators...

  • Ruth Yanai , SUNY College of Environmental Science and Forestry, Syracuse, NY
  • Melany Fisk , Miami University of Ohio, Oxford, OH
  • Tim Fahey, Cornell University, Ithaca, NY

with a host of additional collaborators, including graduate students, technicians, undergraduate students, high school teachers and visiting scientists.


    • Research Opportunites
    • Gretchen Dillon and Alex Rice's theses:
      • Dillon, Gretchen A.  Nutritional effect on causal organisms of beech bark disease in an aftermath forest. PDF
      • Rice, Alexandrea M. Tree variability limits the detection of nutrient treatment effects on sap flow in a northern hardwood forest. PDF
    • It has been a busy 2 weeks, three graduates in one semester! Watch their capstone presentations.
    • Alex Rice presents a poster at the American Society of Agronomy-Crop Science Society of America-Soil Science Society of America International Annual Meeting, November 10-13, 2019, San Antonio, TX

      • Rice, A.M., M.A. Vadeboncoeur, and R.D. Yanai. Relating soil nutrients to ecosystem fluxes. Poster
    • Posters presented at the ESA Annual Meeting, Louisville, KY, August 11-16, 2019

      • Gonzales, K.E. and R.D. Yanai. Foliar N and P concentrations and resorption indicate P limitation in a northern hardwood forest. PDF
      • Hong, D.S. and R.D. Yanai. Foliar nutrient concentrations and resorptions of northern hardwood species in an N x P manipulation study PDF
      • Young, A.R., A. Schweiger and R.D. Yanai. Detecting foliar nutrient status from the sky. PDF
    • Hubbard Brook Ecosystem Study 56th Annual Cooperators' Meeting Presentations

    • LTER Midterm Review, Hubbard Brook, NH, June 3-5, 2019

      • Hong, D.S., K.E. Gonzales, and R.D. Yanai.  Foliar analysis of six northern hardwood species indicates nutrient limitation. PDF
    • Center of Biodiversity at University of Montreal. April 26, 2019

      • Ruth Yanai. The first long-term NXP addition experiment in a temperate forest system. Presentation (must download Abode Connect to view)
    • The Northeast Natural History Conference, Springfield, MA, April 12-14, 2019

      • Bashian-Victoroff, C., L.J. Lamit, R.D. Yanai, and T.R. Horton. Fruiting response of ectomycorrhizal fungi to nutrient additions in Bartlett Experimental Forest, NH. Presentation
    • From the ESF in the High Schools archives: Madison Morley is now an ESF graduate student. Veterinarian medicine’s loss is our gain! PDF
    • First look! Kara Gonzales and Ruth Yanai's paper in now availabe in Oecologia PDF
    • NEW Leaf ID Guide PDF

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