MELNHE

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 6 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;
Christy Goodale, Cornell University, Ithaca, NY;
Joel Blum , University of Michigan, Ann Arbor, MI, and
Ed Rastetter, Marine Biological Laboratory, Woods Hole, MA ;

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

Highlights

Shan Shan's presentation at 2018 ESA Annual Meeting, New Orleans PPT
55th Annual HB Cooperators Meeting. July 11-12, 2018.
Spotlight on Student Research. April 24, 2018. SUNY ESF
- Morley, M.S., G.E. Walsh, and R.D. Yanai. Overachieve and retain the leaves: Nutrients affect fall leaf retention in norhtern hardwood species. PDF
- Hong, D.S., K.E. Gonzales, and R.D. Yanai. Foliar analysis of five northern hardwood species indicates nutrient limitation. PDF
- Barkley, M., S. Kirkpatrick, R.D. Yanai, W. Miller, and A.R. Young. Tardigrade response to nitrogen and phosphorus addition. PDF

Recruiting 2018 Summer Interns, Hubbard Brook and Bartlett Experimental Forests

COOL new findings: Goswami S, M.C. Fisk, M.A. Vadeboncoeur, M. Johnston, R.D. Yanai, and T.J. Fahey. 2017. Phosphorus limitation of aboveground production in northern hardwood forests. Ecology, DOI: 10.1002/ecy.2100.
- Tree growth responded more to P addition than to N addition in mid-aged and mature stands (p=0.02). These results are surprising because temperate forests on glaciated soils have been presumed to be N- limited, but they are consistent with predictions of the MEL model, parameterized for our experimental conditions (Rastetter et al. 2013). We can speculate that P limitation is a result of decades of anthropogenic N deposition.

Research opportunity for high school students. Sign up for a free research course, ESF296, and work with the Multiple Element Limitation in Northern Hardwood Ecosystems (MELNHE) project.