Current Projects

MELNHE: Multiple Element Limitation in Northern Hardwood Ecosystems (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: Quantifying Uncertainty in Ecosystem Studies

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.

Non-Destructive Soil Inventory using Inelastic Neutron Scattering: An Application to Nitrogen Controls on Soil Carbon Storage

Ruth Yanai, State University of New York College of Environmental Science and Forestry, Lucian Wielopolski, Brookhaven National Laboratory, Christy Goodale, Cornell University, Ivan Fernandez, University of Maine, Steven McNulty, USDA Forest Service, and Steven Hamburg, Environmental Defense Fund

Until now, there has not been a method for accurate and rapid evaluation of belowground carbon and nutrient stores, in spite of their ecological, environmental, and economic importance. The variability of forest soils has made it difficult to test factors hypothesized to influence C storage in roots and soil organic matter in realistic field experiments. In particular, anthropogenic N deposition is expected to have a positive effect on belowground C storage, but this effect has not been detectable even in accelerated N deposition experiments.

We propose to demonstrate and develop a transformative new technology for analysis of soil carbon and nutrients. This new technology uses inelastic neutron scattering (INS) to non-destructively quantify belowground stores of carbon and other elements, including coarse roots, which were previously difficult to sample, and around rocks, which were previously obstacles. Our objectives include the development and transfer of this technology for C and N in forest soils and also the advancement of ecosystem science pertaining to soil C and N storage.

In the first year of the proposed project, we will validate the INS measurements with cores taken in the footprint of the INS in stands previously described with quantitative soil pits in the Bartlett Experimental Forest, NH. The capability of the INS to measure N and not just C will be tested for the first time.

In the second year of the project, we will apply INS measurements to permanent plots in two long-term N addition studies. At Mount Ascutney, VT, N has been added to high-elevation spruce-fir forests at rates of 15 and 31 kg/ha/yr since 1988. At Bear Brook Watershed in Maine, 25 kg N/ha/yr has been added to one of a pair of watershed since 1989. The INS measurements will test the hypothesis of increased C storage and also provide a baseline for future sampling. Previous measurements using traditional destructive methods could not be made at the same point on the ground and were thus limited in their statistical power to detect change over time.

Before the INS technology can be widely adopted, it requires demonstration and development. Applying the test of the INS approach in forested sites in stony soils will provide confidence that the system can be used in almost any environment. If successful, the INS technology will allow carbon sequestration projects to come closer to full carbon accounting, making it feasible to include belowground carbon in offset activities in cap and trade programs.

This project is support by the Northeastern States Research Cooperative and a SUNY-ESF Seed Grant.

WERC: Size of discolored hearts of sugar maple

Ruth Yanai and René Germain, SUNY College of Environmental Science and Forestry

Because the most valuable sugar maple trees are those with small hearts, foresters, loggers and landowners would benefit from a heart-size prediction model. Few studies have examined the relationship between dark discoloration size and site or individual tree factors. The initial phase of this study, based on data (bark type, diameter, slope, aspect, etc.) collected from 52 timber sales in 6 states, is nearly complete. The next phase will involve the intensive field study of sites to develop and validate a heart-size prediction model. Future analysis will include stand history and exposure to injury, which is commonly thought to influence dark discoloration in sugar maple. This project is was funded in whole or in part through a grant awarded by the Wood Education and Resource Center, Northeastern Area State and Private Forestry, Forest Service, U.S. Department of Agriculture. In accordance with Federal law and U.S. Department of Agriculture policy, this institution is prohibited from discriminating on the basis of race, color, national origin, sex, age, or disability. To file a complaint of discrimination, write USDA Director, Office of Civil Rights, Room 326-W, Whitten Building, 1400 Independence Avenue, SW, Washington, DC 20250-9410 or call (202) 720-5964 (voice and TDD). USDA is an equal opportunity employer.

Read More:

Yanai, R.D., R.H. Germain, N.M. Anderson, T.A. Coates, and A.K. Mishler. 2009. Heart size of sugar maple sawlogs across the northeastern United States. Journal of Forestry 107(2): 95-100 HTML/PDF ( JOF subscribers) E-print (All other PC users; What's an e-print? )

Modeling forest susceptibility to decline following defoliation by forest tent caterpillar

R.D. Yanai, D. Parry, L.K. Lautz, and D.C. Allen, SUNY College of Environmental Science and Forestry

In the northeastern US, we are in the fourth year of an outbreak of forest tent caterpillar. We are seeking funding to examine the factors that cause some stands to suffer dieback and mortality following defoliation, while other stands recover. This project involves monitoring forest health, analyzing geographic information, including aerial coverage of defoliation history, and working with state agencies and other stakeholders. This project is funded by the Northeastern States Research Cooperative.

Read More:

Wood, D.M, R.D. Yanai, D.C. Allen, and S. Wilmot. 2009. Sugar maple decline following defoliation by forest tent caterpillar. Journal of Forestry 107(1): 29-37 HTML/PDF ( JOF subscribers) E-Print (All other PC users; What's an e-print?)

Cross-site Comparison of Nutrient Cycling and Root Dynamics Along a Calcium Supply Gradient

Jamie Shanley, U.S. Geological Survey; Ruth Yanai, SUNY-ESF; Scott Bailey, USDA-Forest Service; Don Ross, University of Vermont; Tim Fahey, Cornell University; and Tom Siccama, Yale University

We combined existing data and new measurements to compute annual nutrient (nitrogen, phosphorus, sulfur, calcium, magnesium, and potassium) flux in net throughfall, litterfall, and aboveground biomass increment, as well as to account for the belowground biomass component in hardwood and coniferous forest types under contrasting conditions of soil calcium status in Sleepers River, VT; Hubbard Brook, NH; and Cone Pond, NH. The major new effort in this project was directed at measurements of root turnover.

Neither aboveground biomass and production nor belowground biomass were related to soil calcium or calcium: aluminum ratios across the calcium gradient. Hardwood stands had 37% higher aboveground biomass and 44% higher leaf litter production than the conifer stands, on average. Fine root biomass (<2 mm in diameter) in the upper 35 cm of the soil, including the forest floor, was very similar in hardwoods and conifers (5.92 and 5.93 Mg ha⁻¹). The turnover of fine roots increased significantly with soil exchangeable calcium. As a result, calculated fine root production was clearly higher in sites with higher soil calcium in both hardwood and conifer stands. The relationship we observed between soil Ca availability and root production suggests that cation depletion might lead to reduced carbon allocation to roots in these ecosystems. This project was funded by the Northeastern States Research Cooperative.

Park, B.B., R.D. Yanai, T.J. Fahey, T.G. Siccama, S.W. Bailey, J.B. Shanley, and N.L. Cleavitt. 2008. Fine root dynamics and forest production across a calcium gradient in northern hardwood and conifer ecosystems. Ecosystems 11(2):325-341 PDF