Currently Funded Projects

(a.k.a. The Shoestring Project)

Ruth Yanai, State University of New York College of Environmental Science and Forestry, Melany Fisk, Miami University Department of Zoology, Oxford, OH; Tim Fahey and Christy Goodale, Cornell University, Ed Rastetter, Marine Biological Laboratory Ecosystem Center, Woods Hole, MA; Joel Blum. University of Michigan Department of Geological Sciences, Ann Arbor, MI.

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. The project has also been known as the Shoestring Project, since work began on it years before it was funded. The project is currently funded by the NSF and is a renewal of the Northern Hardwood Forest Calcium Cycling Project, which established our sites at Bartlett.

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, developed by Ed Rastetter at the Marine Biological Laboratory in Woods Hole, Massachusetts. To test the patterns of resource limitation predicted by MEL, we are conducting nutrient manipulations in three study sites in New Hampshire: the Bartlett Experimental Forest, the Hubbard Brook Experimental Forest, and Jeffers Brook in the White Mountain National Forest.

At Bartlett, we have three replicate stands of three ages (~20, 30, and > 100 years). At Hubbard Brook and Jeffers Brook, there are two stands at each site, corresponding to the mid-aged and mature stands at Bartlett (total 13 stands). In each stand, there are four treatment plots, each 1/4 ha (50 m x 50 m), treated with N (30 kg/ha/yr as NH4NO3), P (10 kg/ha/yr as NaH2PO4), N+P, or control, beginning in spring 2011. At 5 of the 13 stands, we also have a Ca treatment plot (3500 kg/ha as CaSiO3).

We are monitoring stem diameter, leaf area, sap flow, foliar chemistry, leaf litter production and chemistry, foliar nutrient resorption, root biomass and production, mycorrhizal associations, soil respiration, heterotrophic respiration, N and P availability, N mineralization, soil phosphatase activity, soil carbon and nitrogen, nutrient uptake capacity of roots, and mineral weathering.

This project, under its original title "Co-limitation in Young and Mature Northern Hardwood Forest" is supported by National Science Foundation, and builds upon the Northern Harwood Forest Calcium Project. For more information, please visit the MELNHE website.

QUEST a NSF Research Coordination Network

Mark Green, Plymouth State University, Ruth Yanai, SUNY College of Environmental Science and Forestry, and John Campbell, Forest Service-Northern Research Station

Ecosystem nutrient budgets often report values for pools and fluxes without any indication of uncertainty, which makes it difficult to evaluate the significance of findings or make comparisons across systems. We developed an example of a simple Monte Carlo approach to estimating error in calculating the N content of vegetation at Hubbard Brook, using Excel spreadsheets (Yanai et al. 2010). We are also calculating uncertainty in precipitation inputs and streamwater outputs of nutrients at Hubbard Brook. We have a Working Group funded through the LTER Network Office, involving 6 additional sites, and a proposal in to NSF for a Research Coordination Network.

FOR MORE INFORMATION, PLEASE VISIT THE QUEST SITE.

Read More:

Yanai, R.D., J.J. Battles, A.D. Richardson, E.B. Rastetter, D.M. Wood, and C. Blodgett. 2010. Estimating uncertainty in ecosystem budget calculations. Ecosystems 13(2): 239-248. PDF HTML

Long-Term Ecological Research in New Hampshire

Ruth Yanai, SUNY College of Environmental Science and Forestry Department of Forest and Natural Resources; Melany Fisk, Miami University Department of Zoology; Steven Hamburg, Brown University Center for Environmental Studies; Joel Blum. University of Michigan Department of Geological Sciences; Scott Bailey, US Forest Service Hubbard Brook Experimental Forest; Timothy Fahey, Cornell University Department of Natural Resources.

The health and productivity of northern forests are affected by disturbances such as acidic deposition and harvesting for energy or forest products. We believe that interactive mechanisms of nutrient acquisition are crucial for interpreting forest productivity responses to changing nutrient environments. Our study involves comparing the response of young and mature forests to nitrogen and phosphorus additions at three sites that differ in P availability due to differences in mineralogy of the soil parent material.