My current students | Our support team l Former students l Former Post-Docs l Others that have worked in our lab
My current students
Yang Yang, MS, anticipated completion May 2015
Is it possible to detect change in tree tissue chemistry over time in Northeastern Hardwoods?
My project is detecting the change in tree tissue chemistry over time in Northern Hardwoods. Research conducted in Huntington Wildlife Forest will show a change in concentrations of tree nutrients in different tree components over time and detail the uncertainties in quantifying interannual variability and describe changes over time. This work is partially supported by a Sussman Fellowship.
Yang, Y. 2013.. A description of nutrient variablity within trees in northern hardwood forests. Edna Bailey Sussman Internship Final Report. PDF
Jerome Barner, MS, anticipated completion May 2016
The influence of mychorrizal fungi on nutrient dynamics and cycling processes in northern hardwood forests.
My research consists of evaluating the influence of two major mycorrizal guilds (Ectomycorrhizae and arbuscular mycorrhizae) on nutrient dynamics in northern hardwood forests. Specifically, the influcence on mycorrhizae on nutrient update capacity of fine roots of yellow birch and red maple. Concurrent research includes ectomycorrhizal associations with American beech seedlings across plots with nutrient additions (N, P, and Ca) in the White Mountains, NH.
Kara Phelps, MS, anticipated completion Dec 2016 (co-advised by Dylan Parry)
Kayo Green, MS, anticipated completion Dec 2016 (co-advised by Tom Horton)
Our support team
Heather Engelman, Research Support Specialist. Heather joined the team in 2006, to shepherd lab paperwork, tend our websites and equipment, and support manuscript, poster, and grant preparation and management. Heather's website
Gabriel Smith, Research Aide (RF). Gabriel volunteered over 2013-14 to learn about sample processing. Now a senior, he's supporting sample organization and analysis for MELNHE and LTER..
Stephanie Suttenburg, Research Aide (FWS). Stephanie joined us in the spring of 2013 to lead litterfall sorting, and helps with other projects. She also spent the bulk of the summer working alongside the field crew as a HBR REU's.
Bill O'Neill, Research Analyst. Bill started in the lab as a student Research Aide in 2007, processing soil and plant samples. Following graduation, he continued as a part-time Research Analyst to manage the supply, sample and equipment inventories, process soils, train students to process soils, prepare graphics, and other assorted tasks. He now works on campus primarily during breaks from his other jobs (primarily with Morrisville Auxiliary Corp) to process soils, train students to process soils, and prepare graphics. He also maintains a small sugarbush and raises free-range chicken and turkey.
Craig See, Research Analyst. Craig joined the team as a graduate student and research assistant. He continued as a crew chief (2012-13) and Research Support Specialist, processing samples for the MELNHE project, and managing QUEST social media. In his current title, he supports manuscript preparation and social media.
Adam Wild, Research Analyst Adam joined the Shoestrings in the summer of 2012, continuing as a grad student and field crew member. He served as field crew chief, summer 2014. Now at SUNY Cobleskill, he's still with us a few hours a week, remotely supporting data documentation.
Franklin Diggs, MS, December 2014
Mycorrhizal colonization of roots: soil depth and species composition.
My work involves investigating root colonization by mycorrhizal fungi across depth and stand age and the use of molecular techniques in monitoring mycorrhizal systems. I work out of the White Mountains in New Hampshire as part of the Multiple Element Limitation in Northern Hardwood Ecosystems. His thesis has been defended, and he is finalizing his revisions.
Yanai, R. 2013. Sustainable nutrient supply after forest harvest: characterizing the fungal link from soils to roots. Final Report to the McIntire-Stennis Cooperative Forest Research Program.
Yi "Tony" Dong, MS, August 2014
Effects of Rock-Derived nutrients in N cycling in Northern hardwood forests.
The weathering of parent material is the primary source of Ca, Mg, K, and P in soils and ecosystems. The influence of rock-derived nutrients on N cycling is less often investigated. Here, we investigated the geochemical compositions of soil mineral nutrients of mineral horizon in 20 sites in the White Mountains of New Hampshire, United States. Total soil N content, foliar N concentration, and N mineralization were compared among sites located on different types of bedrock. Total soil N content was significantly higher in sites located on Rangeley schist than sites located on the Conway, Mt. Osceola, and Kinsman granites. Foliar N and N mineralization were not related to bedrock types. Nitrogen mineralization was closely related to foliar N concentration, soil C/N ratio and soil exchangeable Ca. Nitrogen mineralization rate was higher when foliar N concentration increased, but was inhibited by the soil C/N and soil exchangeable Ca. Rock-derived nutrients may deserve more attention as a control on N accumulation in ecosystem development.
Where is he now? A GIS training program.
Adam Wild, MS, May 2014
Sugar content yield in the sap of sugar maple following fertilizer applications.
Adam looked at a new component of the MELNHE project, taking advantage of recent fertilizer applications to investigate their impact on sugar maple sap flow and sugar content. Might you get a sweeter yield from a Ca fertilized sugarbush? Adam's work is supported by a NSRC Graduate Student Award.
Where is he now? See Our support team
Kikang Bae, PhD, December 2013
Interactive effects of nutrient and forest age on total belowground carbon allocation in northern hardwood forests in the White Mountains of New Hampshire
Soil is the largest terrestrial reservoir of carbon, containing an estimated 1,550 Pg and almost three times more carbon than is contained in global vegetation (~500 Pg). More studies have been focused on vegetation because soil carbon stock is complicated to study, represents a high spatial variation, and changes very slowly. However, the effect of forest ecosystems by disturbances or by forest management on belowground carbon exchange is at least as important as aboveground effects on the global carbon budget. This study aims to compare soil carbon dynamics after forest harvest associated with variation in site fertility and forest ages, the most sensitive factors of belowground carbon allocation, in northern hardwood forests in the White Mountains of New Hampshire. Kikang also hopes to determine changes of root respiration with trenching and root turnover with minirhizotron tubes after fertilization (+N, +P, +NP) across forest ages and determine the colonization rate of roots by andomycorrhizal fungal (AMF) and ectomycorrhizal fungal (EMF) on roots, and identify the EMF communities in surface and deep soils of young and old forests.
Where is she now? Programme Consultant, International Cooperation Division, International Affairs Bureau, Korea Forest Service
Craig See, MS, December 2013
Soil nitrogen affects foliar phosphorus resorption in a co-limited system
Craig is contributing to the MELNHE project, which investigates possible nutrient co-limitation of northern hardwood forests. His current research focuses on above ground nutrient cycling in northern hardwood forests. He is also working on a project investigating of the effects of historic land use on nitrogen transformations in lawns, and conducting an uncertainty analysis of long term atmospheric deposition at the Sevilleta LTER in New Mexico.
See, C.R. 2012. The grass is always greener: nitrogen processes in lawns and adjacent forest land in the White Mountains, New Hampshire. Edna Bailey Sussman Internship Final Report. PDF
Where is he now? see Our support team
Carrie Rose Levine, MS, August 2011
Assessing the suitability of rotary corers for
sampling exchangeable cations in rocky soils
Carrie Rose has been comparing the results of soil sampled via traditional excavation with that sampled by neutron-induced gamma-ray spectropscopy (INS). Her sites are located at Hubbard Brook, Bartlett Experimental Forests, and Mt. Ascuteny with equipment and personnel of the Brookhaven National Laboratory.
Wielopolski, L., R.D. Yanai, C.R. Levine, S. Mitra, and M.A Vadeboncoeur. 2010. Rapid, non-destructive carbon analysis of forest soils using neutron-induced gamma-ray spectroscopy. For. Ecol. Manag. 260(7): 1132-1137 PDF
Levine, C.R. 2010. Development of an inelastic neutron scattering approach to assess carbon and nitrogen contents of forest soils: an internship with the Brookhaven National Laboratory, Upton NY. Edna Bailey Sussman Foundation Research Report. PDF
Yanai, R.D. 2011. Non-Destructive Inventory using Inelastic Neutron Scattering: An Applicaiton to Nitrogen Controls on Soil Carbon Storage. Northeastern States Research Cooperative Final Report PDF
Where is she now? After graduation, she stayed at ESF as a Senior Research Support Specialist to coordinate stakeholder involvement, monitoring efforts, and analyses of S, N and Hg monitoring efforts through a NYSERDA fellowship program (See Levine, Carrie R. and R. D. Yanai. 2012. Assessment of Long-Term Monitoring of Nitrogen, Sulfur, and Mercury Deposition and Environmental Effects in New York State. New York State Energy Research and Development Authority Final Report 12-21. PDF ). She began a PhD program with John Battles, UC-Berkeley, August 2012. website
Justin Holgerson, MPS, 2011
Where is he now? Ecologist, Anchorage Forestry Sciences Laboratory, USFS.
Allison Bodine, MPS, 2010
Where is she now? Research Analyst-Urban Forestry, US Forest Service Northern Research Station, Syracuse, NY.
Steve Currie, MPS, 2010
Where is he now? Biologist/Soil Scientist, U.S. Army Corps Army Corps of Engineers, Buffalo District. I am working in regulatory overseeing permit applications and wetland jurisdictional determinations.
Nick Pitel, MS,
An assessment of sugar maple condition following defoliation by forest tent caterpillar: investigating soil chemistry
Sugar maple (Acer saccharum Marsh.), a keystone species of northern hardwood forests, is susceptible to decline especially on sites with low soil Ca and Mg, and is commonly stressed by forest tent caterpillar (FTC; Malacosoma disstria Hübner). soils and assessed the condition of sugar maple trees using consecutive years of data from North American Maple Project (NAMP) stands in Massachusetts, Vermont, and New York. Mortality was highest in plots that had the most crown dieback the previous year. As expected, plots with sugar maple mortality occurred on soils with low concentrations of Ca, Mg, and K. Low soil K was the soil variable that correlated best with sugar maple crown dieback and mortality. I suggest that more attention be paid to K concentrations in soils when investigating sugar maple condition.
Wood, D.M., R.D. Yanai, D. Parry, and N.E. Pitel. 2010. Forest fragmentation and duration of forest tent caterpillar (Malacosoma disstria Hübner) outbreaks in northern hardwood forests. For. Ecol. Manag. 260(7):1193-1197 PDF
Where is he now? Conservation Planner, Massachusetts Association of Conservation Districts.
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Andrew Mishler, MS,
Size of discolored hearts of sugar maple
Dark discolored sugar maple wood is less valuable than the lighter colored sapwood. Factors leading to the prediction of this characteristic would be very helpful to foresters and timber managers. Few studies have examined the relationship between dark discoloration size and site or individual tree factors. This project evaluated some of these characteristics (bark type, diameter, slope, aspect, etc.). Future analysis will include stand history and exposure to injury, which is commonly thought to influence dark discoloration in sugar maple.
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 PDF
A second paper is in preparation.
Where is he now? Forester, USFS, Mendocino National Forest. Andrew's primary responsibility is Timber Sale Administration.
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Tim Porter, MPS,
As an MPS student, Tim took advantage of the opportunity to intern for a non-profit agency in Boston. He returned to that agency as an urban forester a few years later.
Where is he now? CityRoots Program Coordinator, Urban Ecology Institute. I’m working with local communities in various urban forestry areas (i.e. coalition building, inventory and tree planting training, GIS development, and other areas). I’m also involved with UEI’s coordination of activities related to Boston Metro Urban Long-Term Research Area proposal, Urban Ecology Collaborative, and the Massachusetts Department of Conservation and Recreation.
Dustin Wood, MS,
Evaluating the susceptibility of sugar maple stands to defoliation by forest tent caterpillar (Malacosoma disstria Hübner) and the vulnerability to decline.
The recent outbreak of Forest Tent Caterpillar (FTC) in the northeastern U.S. has devastated millions of acres of forestland, resulting in widespread dieback, loss of vigor, and in some cases mortality. However, some forest stands have been more resilient to defoliation stress than others. The objectives of this study were to 1) determine if dieback, loss of vigor, and mortality in forest stands were greater when the stand was defoliated, and 2) determine the site, stand, or tree characteristics that can be used to predict dieback, loss of vigor, and mortality in forest stands following FTC defoliation, and using regression, incorporate them into a hazard rating model.
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 PDF
Wood, D.M., R.D. Yanai, D. Parry, and N.E. Pitel. 2010. Forest fragmentation and duration of forest tent caterpillar (Malacosoma disstria Hübner) outbreaks in northern hardwood forests. For. Ecol. Manag. 260(7):1193-1197 PDF
Where is he now? Forester, NYSEG, Binghamton, NY.
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Paul Lilly, MS, 2007
Cation exchange chemistry and the long-term effects of liming on acidic forest soils in the northeastern United States
I collected samples from four previously established liming experiments in order to characterize the long-term effects of liming on cation exchange properties and test various proposed models for the relationships between pH, base saturation (BS), and cation exchange capacity (CEC). Limed sites generally had higher pH and BS, more organically bound Al and less bound hydrogen, and fewer E horizons. Limed organic horizons had lower organic matter content than controls, and limed mineral horizons had lower effective CEC, suggesting that podzolization may be disrupted or masked in limed soils. Regression analyses testing models of charge development on organic matter suggest that sites binding non-exchangeable Al should be excluded from the pool of potentially dissociable functional groups. Results for models of exchangeable cation equilibria suggest that exchangeable Al does not behave as a base cation, but rather is part of an equilibrium with organically bound Al that buffers pH change.
Where is he now? Paul completed a PhD, University of Vermont, December 2011, and is now a Senior Scientist at the San Francisco Bay area.eco-think tank Spatial Informatics Group .
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Farrah Fatemi, MS, 2007
Aboveground biomass and nutrients in developing northern hardwood stands in New Hampshire, United States
Accurate estimates of biomass and nutrient stocks in young second-growth forests are critical for assessing ecosystem productivity and the contribution of these forests to regional and global nutrient cycles. Forest biomass in northeastern temperate forests is commonly estimated using previously established allometric equations. Most allometric equations for smaller trees (2-12 cm dbh) and corresponding nutrient stock estimations have been developed using smaller trees from older stands (>50 yrs since last cut). To study how the prediction of biomass and nutrients stocks based on tree diameter vary with stand age, we studied six developing stands in and around the Bartlett Experimental Forest, in the White Mountains of New Hampshire. We developed allometric equations for aboveground biomass and nutrients of six northern hardwood species in two young (~15 yrs old) and two middle-aged stands (~30 years old). We also conducted non-destructive tissue sampling and made measurements to estimate biomass and nutrients in two old stands (>100 yrs old). Results from this study indicate that most allometric equations developed from this study in younger stands are very similar to those developed by other authors for the same species in older stands for total aboveground and wood biomass. However, we suggest that for components such as foliage, bark and branches, site- or age-specific biomass equations should be used in order to accurately assess aboveground biomass. Additionally, some tissue nutrient concentrations (K, P and N) were significantly different in young and old stands, necessitating age-specific nutrient concentrations for accurate estimations of some nutrient stocks.
Read More: Papers are forthcoming from this research.
Where is she now? She completed a PhD, University of Maine, in 2011; a Teaching Post-Doc at Villanova University, was Post-doctoral Research Fellow in the University of Alberta's Department of Renewable Resources. She is now an Assistant Professor of Environmental Studies, St. Michael's College, Colchester, VT More Info
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Byung Bae "BB" Park. PhD, 2006
Fine root dynamics and tissue chemistry across a calcium gradient in temperate hardwood and softwood forest ecosystems.
The effect of nutrient availability on the chemistry of fine roots and root turnover is important to terrestrial carbon and nutrient cycling, but it is poorly understood. Differences in sensitivity to soil fertility across tree species and developmental stage may influence forest response to environmental change, but these rarely have been compared in the field.
I estimated fine root biomass (FRB), fine root production, and nutrient turnover by coring and minirhizotron technique and aboveground production by allometric equations of hardwoods and softwoods at three Ca gradient sites: Sleepers River, VT; Hubbard Brook, NH; and Cone Pond, NH. I also measured annual growth rates and tissue chemical concentrations among species and growth stages in two contrasting base cation sites at Huntington Forest, NY.
Fine root biomass varied across sites, from 465 g m -2 to 682 g m -2 , but there were no statistically significant differences among sites within forest type. Root biomass density declined with depth; 57 and 66% of FRB for hardwoods and softwoods, respectively, occurred 10 cm above soil. Surprisingly, the ratio of dead to live roots in softwoods increased as a function of depth, but there was no such change in hardwoods. Fine root turnover rates varied from low (0.62-0.71 yr -1 ) to high (1.32-1.86 yr -1 ) as Ca gradient. Fine root production ranged from 1.2 to 3.7 Mg ha -1 yr -1 for hardwood stands and from 0.9 to 2.3 Mg ha -1 yr -1 for softwood stands. Although FRB and leaf litter production were not significantly correlated to soil fertility, fine root production and the ratio of root production to leaf litter production were clearly higher in sites with higher soil fertility.
Root nutrient concentrations were significantly affected by site and root diameter. Calcium and Mg concentrations in live roots were greatest in sites with the highest concentrations of base cations. Calcium concentrations were higher in the larger roots, but P, N, and Al concentrations were higher in the finer root classes. Among sites, I found significant differences of nutrient turnover by fine roots, but not between forest types. Magnitude of differences between sites for each element ranged from 3 times for P and N to 8 times for Ca and Mg, but differences between forest types were less than 2-fold. Root Ca turnover ranged from 3 to 23 kg ha -1 yr -1 increasing exponentially with soil Ca saturation increased. The Ca gradient study suggests that greater nutrient availability leads to greater carbon allocation and nutrient inputs belowground in north temperate forest ecosystems.
Huntington Forest, sugar maple growth (14.8 cm 2 yr -1 per
tree) at the site with higher base cations was much greater than at the other
site (8.6 cm 2 yr -1 per tree), but the growth of beech
was not different between the two sites. Root and foliar Ca, K, and Al
concentrations were positively correlated with soil elements, but Mn
concentrations were negatively correlated. Sugar maple differed more than beech
between sites in foliar K, Mn, and Zn concentrations. Sugar maple seedlings
differed more than mature trees in nutrient concentrations in roots. The
sensitivity of sugar maple seedlings to nutrient availability could ultimately
contribute to the replacement of sugar maple by American beech in regions of low
pH and base cations if base cation leaching by anthropogenic deposition and tree
harvesting continues. (Abstract shortened by UMI.)
Park, B.B., R.D. Yanai, M.A. Vadeboncoeur, and S.P. Hamburg. 2007. Estimating root biomass in rocky soils using pits, cores and allometric equations. Soil Sci. Soc. Am. J. 71:206-213. PDF
Yanai, R.D., B.B. Park, and S.P. Hamburg. 2006. The vertical and horizontal distribution of roots in northern hardwoods of varying age. Can. J. For. Res. 36(2): 450-459. PDF
Park, B.B., R.D. Yanai, J.M. Sahm, D.K. Lee and L.P. Abrahamson. 2004. Wood ash effects on plant and soil in a willow bioenergy plantation. Biomass and Bioenergy. 28(4):355-365. PDF
Park, B.B., R.D. Yanai, J.M. Sahm, B.D. Ballard, and L.P. Abrahamson. 2004. Wood ash effects on soil solution and nutrient budgets in a willow bioenergy plantation. Water, Air, and Soil Pollution 159:209-224. PDF
Effect of Silvicultural Treatments on Carbon Storage of Northern Hardwood Forests Roosevelt Wild Life Station website
Where is he now? BB left the Korea Forest Research Institute (KFRI), Department of Forest Conservation, Dongdaemun-gu, Seoul, South Korea, for a teaching position in the Department of Environment and Forest Resources, Chungnam National University, Daejon, Republic of Korea
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Melissa Lucash, PhD, 2006
Methods for measuring nutrient uptake rates of intact roots of seedlings and mature trees
Most studies measuring uptake rates of trees use excised roots, even though excision may lower uptake. In my research I used intact roots to improve estimates of specific uptake rates by seedlings and mature trees.
To determine how uptake varies throughout the year, I measured the temporal variation of nutrient uptake capacity of K+ , NH4+ , NO3- , Mg2+ and Ca+2 in mature loblolly pine trees. I expected net uptake to be positive throughout the year but I observed net efflux of K+ , NH 4+ and NO3- in July. I also measured uptake at several solution concentrations, expecting uptake to increase with concentration. I observed this pattern in April but not July or October. In October, uptake was constant across concentration; antecedent nutrient concentrations affected the temporal patterns of uptake in July. As expected, I found greater uptake of NH4+ than NO3- . Temporal patterns of uptake capacity are difficult to predict, since experiment duration, antecedent conditions and nutrient solution concentration, affect measured rates of uptake.
I used a sequence of treatments to measure the effect of disturbance during measurements of NO3- uptake. First, I measured uptake by loblolly pine seedlings in intact columns of sand using the SUM (soil uptake monitoring) method. Second, I removed the seedlings from the columns and measured their uptake using the hydroponic method. Third, I transferred the plants back into the SUM columns. As predicted, uptake by undisturbed SUM plants was higher than plants which had been excavated and repotted back into SUM columns. In addition, transferring plants from the SUM columns to hydroponics caused a delay in uptake. The SUM column technique holds promise for conducting nutrient uptake studies with minimal disturbance to the root.
I reviewed current techniques suitable for measuring uptake by
roots of mature trees. Estimates of uptake obtained using these methods are
affected by the sampling scheme, experimental conditions, excision, ion
concentrations and the rate of ion efflux. I also discussed two new techniques,
the SUM column technique described above, and digital autoradiography. A greater
focus on methods development is critical to more accurately measuring uptake of
mature tree roots under field conditions.
Lucash, M.S., R.D. Yanai, and J.D. Joslin. 2008. Nutrient uptake by intact and disturbed roots of loblolly pine seedlings. Environmental and Experimental Botany 64: 15-20 PDF
Lucash, M.S., D.M. Eissenstat, J.D. Joslin, K.J. McFarlane and R.D. Yanai. 2007.Estimating nutrient uptake by mature tree roots under field conditions: challenges and opportunities. Trees - Structure and Function 21(6):593-603. PDF
Lucash, M.S., R.D. Yanai, and J.D. Joslin. 2005. Temporal variation in nutrient uptake capacity by intact roots of mature loblolly pine. Plant and Soil 272:253-262. PDF
Yanai, R.D., P. Sollins, and M.S. Lucash. 2003. Ecosystem ecology: in pursuit of principles. Ecology 84:1640. PDF
Where is she now?
Research Faculty, Dynamic Ecosystems and Landscape Laboratory, Portland
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Pete Homyak, MS, 2006
by woodchip application: protecting water quality in a northern hardwood forest.
Forest harvesting can have adverse effects on stream water chemistry by lowering pH, ANC, and increasing nutrient concentrations. Since forestry best management practices do little to directly address the effects of harvesting on stream chemistry, my research investigated the potential of wood chips derived from logging slash to immobilize inorganic N in a patch cut of northern hardwoods in NY. Although further research is needed to better quantify the duration of the N immobilization period, surface applied wood-chips have the potential to limit inorganic N input to streams for at least the first year following cutting. The objective of this project is to provide forest managers with an alternative to limit potential negative impacts on water quality.
Homyak, P.M., R.D. Yanai, D.A. Burns, R.D. Briggs, and R.H. Germain. 2008. Nitrogen immobilization by wood chip application: protecting water quality in a northern hardwood forest. Forest Ecology and Management 255: 2589-2601. PDF
Where is he now? NSF Postdoctoral Associate at UC-Santa Barbara, studying "Biotic and Abiotic control of soil gaseous N emissions in semiarid ecosystems" with Dr. Josh Schimel. Pete's webpage
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Kimberly Bohn, PhD, 2005
Residual spatial structure and implications for sawtimber production in uneven-aged northern hardwoods after selection system silviculture or diameter-limit cutting
Selection system silviculture in uneven-aged stands places more emphasis on residual stand conditions compared to diameter-limit cutting. Differences in stand conditions may affect the ability to sustain sawtimber production as well as non-commodity values over the long-term. Previous work has evaluated the effect of these treatments on stand diameter distributions and growth but not on spatial structure of residual trees. I developed a simulation process for evaluating long-term changes in spatial structure and sawtimber production over a range of initial stand conditions represented on 10 stem maps.I evaluated changes in spatial structure using two methods. Variability of sawtimber spacing was greater after diameter-limit cutting than selection system for each of three cuttings, although differences between treatments decreased during the growth periods between cuttings. No differences were detected in spacing of the poles using variability of basal area as a measure. However, results from the Ripley's K statistic indicated that clumping developed in the pole classes during the growth period following the initial diameter-limit cut. Sawtimber trees were uniformly spaced after selection system and randomly spaced after diameter-limit cutting.
I evaluated sawtimber production and yield on same set of plots used to study spatial structure. Simulated selection system silviculture resulted in consistent sawtimber yields over three cutting periods, with greater than 75% of the volume in medium and large sawtimber. With repeated diameter-limit cutting, sawtimber harvests declined significantly at the second and third entries, and the majority of the volume from these cuttings came from small sawtimber. Comparisons of treatments across individual plots varied by several thousand board-feet, in part because of the large variability in yields from diameter-limit cutting.
Differences in both spacing
and the density of trees affected comparisons of sawtimber volume production
after selection system or diameter-limit cutting. The greater sawtimber volumes
obtained by the simulated selection system treatments may reflect a combination
of factors, including more uniform spacing, more optimal densities, and the
presence of large residual trees. Further research should evaluate the degree to
which these factors influence stand-level production.
Bohn, K.K., R.D. Nyland, and R.D. Yanai. 2011. Comparing selection-system and diameter-limit cutting in uneven-aged northern hardwoods using computer simulation. Can. J. For. Res. 41(5): 963–973 doi: 10.1139/x11-027 PDF
Where is she now?
Associate Professor, University of Florida, West Florida Research and Education
Center (WFREC), Milton, FL
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Karis McFarlane, MS, 2003
Measuring nutrient uptake by roots of sugar maple, red pine, and Norway spruce trees in situ
Freshly excavated intact roots often release nutrients in nutrient uptake experiments, possibly due to disturbance caused during excavation. I tested the effect of four pre-experiment treatments on net uptake of nutrients by sugar maple ( Acer saccharum Marsh.), red pine ( Pinus resinosa Ait.), and Norway spruce ( Picea abies (L.) Karst.) in monospecific plantations in central New York. Roots were (1) "trained" to grow in a sand-soil mixture, (2) excavated and exposed to nutrient solution for two or (3) four days, or (4) freshly excavated. Roots were then exposed sequentially to three concentrations of nutrient solutions for 2 hours each. Net uptake rates increased with concentration for ammonium, nitrate, phosphate, potassium, sodium, and aluminum for all species. Net efflux of calcium increased with increasing concentration. Magnesium was not consistently taken up or released by all species. None of the pre-treatments improved uptake measurements consistently across all combinations of nutrients and species studied.
McFarlane, K.J. and R.D. Yanai. 2006. Measuring nitrogen and phosphorus uptake by intact roots of mature Acer saccharum Marsh., Pinus resinosa Ait., and Picea abies (l.) Karst. Plant and Soil 279(1-2): 163-172. PDF
Where is she
now? Research Scientist, Center for Accelerator Mass
Spectrometry, Lawrence Livermore National Laboratory
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Vincent Giorgio, MPS,
As part of my degree program, I was involved in a research project in Baltimore MD through the Baltimore Ecosystem Study (under the direction of Dr. Katalin Szlavecz at Johns Hopkins University and Dr. Richard Pouyat of the US Forest Service). The project involved investigating various soil physical, chemical, and biological properties from urban to rural forest patches. The goal was to determine if an urban-rural gradient could be identified as was described in the literature from studies in the NYC area.
A total of 52 soil samples were collected and analyzed for bulk density, pH, organic matter content, texture, and nutrient content. Earthworm and macroarthropod samples were also collected at each sampling location. Significant differences (p <. 0.05) between urban/rural sites were found for bulk density, soil Ca, Mg, and Na with urban sites showing higher values than rural for each. Earthworm density and biomass varied between 10 and 71 ind. m-1 and 3.7 and 75.1 g m-1 respectively. Earthworm biomass showed positive correlation with pH, and negative correlation with soil organic matter content and leaf litter depth. Species composition was a better indicator for site conditions than abundance. Due to the low rainfall that year, microarthropod samples yielded insufficient data to conduct analyses. Cluster analysis showed that underlying geology was just as important as land use in explaining observed differences between urban/rural sites, indicating that natural phenomenon are likely to be as important and anthropogenic influences.
received a Masters in Public Administration (MPA) from Syracuse University’s
Maxwell School with a concentration in state and local government. My program
of study included a year-long internship with the USEPA Environmental Finance
Center, Region 2, which involved providing technical assistance to local
government officials with respect to planning and financing of water and sewer
Where is he now? Since 2003, I have been the Associate Project Manager for the NYC Dept of Environmental Protection, Bureau of Water Supply. My job involves facilitating, planning, coordinating, and implementing capital projects and education/outreach programs associated with the City’s Long-Term Watershed Protection Program, Kensico Reservoir Water Quality Control Program, and East of Hudson Nonpoint Source Management Plan.
Sarah Kulpa, Honors Thesis, 2002
Calcium and potassium efflux during measurements of nutrient uptake by intact tree roots
Where is she now? Senior Regulatory Specialist, Hydropower Services, Syracuse, NY.
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Richard Phillips, MS, 1999
The effects of calcium chloride and aluminum chloride additions on rhizosphere soil and suger maple (Acer saccharum Marsh.) fine root chemistry
Calcium chloride (CaCl2) and aluminum chloride (AlCl3) additions were used to induce changes in Ca and Mg availability in eight experimental plots at the Hubbard Brook Experimental Forest, NH. Soils (rhizosphere and bulk) and sugar maple fine roots were sampled in the Oa horizon and the upper 10 cm of the mineral soil. In the Oa horizon of AlCl3 treated plots, exchangeable Al was 42% greater (p < 0.05), exchangeable Mg was 31% lower (p <$0.1) and (Ca + Mg)/Al ratios were 54% lower (p <$0.1) than in control plots. Fine roots in the Oa horizon had 21% less Ca (p < 0.1), 30% less Mg (p < 0.1) and 42% lower (Ca + Mg)/Al ratios (p < 0.05) in AlCl3 treatments than controls. Rhizosphere soil and fine root (Ca + Mg)/Al ratios were strongly correlated (r = 0.84; p < 0.001) irrespective of treatments or horizon. Rhizosphere soils were depleted in Al and organically bound Al (Alo) relative to bulk soil irrespective of treatment or horizon. Rhizosphere soil Alo was negatively correlated with (Ca + Mg)/Al ratios in fine roots (r = 0.85; p < 0.001). These results suggest that (Ca + Mg)/Al ratios in rhizosphere soil may be good indicators of sugar maple fine root nutrition because they account for differences in Al mobilization in the rhizosphere.
Phillips, R.P. and R.D. Yanai. 2004. The effects of AlCl3 additions on rhizosphere soil and fine root chemistry of sugar maple (Acer saccharum). Water, Air, and Soil Pollution 159: 339-356. PDF
Yanai, R.D., R.P. Phillips, M.A. Arthur, T.G. Siccama, and E. Hane. 2005. Spatial and temporal variation in calcium and aluminum in northern hardwood forest floors. Water, Air, and Soil Pollution. 160: 109-118. PDF
Where is he now?
Associate Professor, Indiana University, Department of Biology
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David Ray, MS, 1997
Patterns of development in three Adirondack northern hardwood stands following herbicide treatment and shelterwood cutting
A combination of remeasurement and chronosequence techniques were used to examine patterns of early development in three Adirondack northern hardwood stands for a period of 4 to 26 years following shelterwood seed cutting to 35 to 65% canopy cover. Mist blowing and stem injection of herbicide controlled a dense American beech (Fagus grandifolia Ehrh.) understory in these stands, leaving them devoid of advance regeneration. Deer (Odocoileus virginianus borealis Miller) populations had also been reduced by hunting and through natural losses. Both treatments have proven necessary for successful regeneration of diverse and commercially viable stands in the region. Cohort development was described as numbers of stems by size class from time of cutting. Total stems ≥1' tall and ≥ 1" dbh followed distinct patterns of development among stands, while those ≥ 3'and ≥6" tall were more variable. Total stems ≥ 1' tall peaked around 5 years after seed cutting, suggesting most new individuals had arrived and begun to grow by that time. By 10 yrs, stems ≥1' tall were declining substantially, indicating crown closure had led to stratification and competition-induced mortality within the new cohort. By 20 yrs, total stems ≥ 1" dbh were at a maximum. By 25 yrs, the numbers of stems ≥1" dbh had begun to decline. Non-linear regression techniques were used to model the consistent patterns of development observed between the stands. Functions describing the composite behavior of total stems by size class are presented, and a biological rationale for the observed patterns is discussed.
Nyland, R.D, Ray, D.G., R.D. Yanai.
2004. Height Development of upper-canopy trees within
Yanai, R.D., D.G. Ray, and T.G. Siccama. 2004. Lead reduction and redistribution in the forest floor in New Hampshire northern hardwoods. J. Environ. Qual. 33:141-148. PDF
D.G. Ray, R.D. Yanai, R.D. Briggs, L. Zhang, R.
Cymbala, and M.J. Twery.
2000. Early cohort development following even-age reproduction method cuttings
Ray, D.G., R.D. Nyland, and R.D.
Yanai. 1999. Patterns of early cohort development
following shelterwood cutting in three
Where is he now?
Conservation Forester, The Nature Conservancy, Salisbury, MD and PhD student, University of Maine.
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Melissa Lucash, 2008-2010
Where is she now? see above.
Byung Bae Park, 2006-2007
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
Where is he now? see above.
Swee-May (Tang) Cripe, 2004
Where is she now? Assistant Professor of Epidemiology and Director of the Epidemiologic Research Unit at Perdana University Graduate School of Medicine, Malyasia website
Tjeerd Bouma, 2004
Bouma, T.J., D.M. Eissenstat, R.D. Yanai, U. Hartmond, L. Wang, D. Flores, and A. Elkin. 2001. Estimating age-dependent costs and benefits of roots with contrasting lifespan: comparing apples and oranges. New Phytol. 150:685-695. PDF
Where is he now? Spatial Ecology Researcher, Netherlands Institute of Ecology Centre for Estuarine and Marine Ecology TJ's webpage
Elizabeth Hane, 2003
Where is she now? Assistant
Professor, RIT, Departments of Biological Sciences and Environmental Sciences
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Others that have worked in our lab
Ben Porter, Volunteer, 2013-14. Ben sorted many litterbugs!
Brannon Barr, 2013-24
Brannon joined the team in the summer of 2013, with the intent of pursuing a PhD. He moved to EFB to work with Gord. Patterson.
I am interested in determinants of species distributions and abundances at the community and landscape scale, related species interactions such as colonization, competition, predation, and symbiosis, the evolution of life history characteristics, and how these phenomena are related to resource supply rates and nutrient fluxes.
Dr. Haiyan Wang, Visiting Scholar, Beijing Forestry University's Department of Soil Science
Dr. Wang collected soil and tissue samples among the MELNHE sites over the summer, and she is contrasting them during her sabbatical at ESF.
Alex Goeler, Volunteer, Fall 2013
Alex helped sort samples.
Dan Winters, Research Aide (FWS), Fall 2013.
Dan led litterfall sorting, and helped with other projects.
Guole Shi, Wendy Huang, and Rose Petersky, 2011-2012
Guole, Wendy and Rose helped with a variety of experiments to assist with their proposals for future independent study and capstone projects.
Dr. Matt Vadebonceour, 2010-12.
Matt was a Research Analyst supporting summer field work planning on an official basis beginning in 2010, co-coordinating the planning efforts and applications in New Hampshire. He was involved with the MELNHE project in its earlier iteration as the Calcium project in former capacities at Brown University, and remained involved either as a consultant or RA while he pursued his doctorate at the University of New Hampshire.
Where is he now? Matt remains vested in MELNHE as a consultant, but is officially a Post Doctoral Associate at UNH, working on sapflow with Heidi Asbjornsen. Matt's website
Allison Speicher, Summer 2012.
Allison climbed lots of trees, collecting lots of foliage for Yang Yang's chemical analyses.
Where is she now? Community Support Specialist, Enable CNY.
Jun Cui, Summer 2012.
"Daisy" helped with MELNHE field work.
Where is she now? Pursuing a MLA degree upstairs in the Department of Landscape Architecture.
Pilar Lyons, Spring 2011
Pilar supported sample processing and analysis, as well as statistical analysis and publication graphics.
Where is she now? Project Engineer, CDH Energy Corp, Cazenovia, NY. Pilar's website
Stephanie Anos, Spring 2011
Stephanie assisted in an number of experiments to fulfill requirements for ESF's fledgling Undergraduate Scholar program.
Where is she now? Stephanie is still at ESF, but has moved to another lab for the next phase of her program.
Corrie Blodgett, 2009-2012
Corrie led seasonal New Hampshire field work, and provided remote statistical assistance through the winter months. She also participated in the original Calcium project as undergraduate student at RIT.
Where is she now? She teaches chemistry and physics at Sacopee Valley High School, Hiram, ME.
Haichao helped with the Shoestring Project and participated in weekly lab meetings during Fall 2011, and helped with our summer 2012 field measurements.
Where is he now? Upstairs, working on a Master's of Landscape Architecture.
Braulio "Bali" Quintero
Bali started his PhD program studying above ground nutrient cycling through reallocation, but transitioned to a program in ecosystem ecology and energy budgets of Puerto Rico.
Where is he now? Bali brought the new students on the MELNHE project up to speed as he transitioned to the GPES program. In 2013, Bali Visit Bali at ISER Caribe
Zhen Lu "Amos" Lim, 2011-12
Amos completed an independent study project with me and Tom Horton over the course of the year, and helped a number of our students Project
Where is he now? Amos joined Kabir Peay's lab, Stanford University, as a Research Technician working primarily in Malaysia. He now works with Action AAA Foundation, closer to home in Malaysia.
Lin Liu, 2010-11
Lin completed two independent study projects focusing on symbiotic relationships between our tree species of interest and mychorrizal communities while an exchange student at SUNY-ESF. She then participated in the Ecosystem Ecology and Applications Program for [non-matriculated) International Students, gaining field experience to complement the projects she worked on during the academic year. Where is she now? She returned to Sichuan University for the final year of her degree program, and is now pursing a MS in the Department of Geological Sciences (Hydrogeology), Michigan State University. profile
Elizabeth Murphy, 2010-11
Elizabeth supported sample processing and data documentation for the Shoestring (MELNHE) project.
Where is she now? Middle School Science and Health Teacher, The Red Oaks School, Morristown, NJ profile
Frank Cetera, 2006-2010
Frank worked on both phases of the "Heartwood Project."
Where is he now? Frank stays pretty busy! He is a facilitator at Syracuse Permaculture and Urban Homesteading Guild, Green Business Advisor at Small Business Development Center at Onondaga Community College, Steering Committee Member and Founding Member at Syracuse Grows, and Co-Founder and Board President at The Alchemical Nursery Project, Inc.
JiYoung An, 2010
JiYoung An was the first participant in the Ecosystem Ecology and Applications Program for [non-matriculated] International Students. Over the summer of 2010, she gained experience processing soils, sorting and analyzing litter, and measuring trees.
Where is she now? Jiyoung returned to Seoul National University to complete her forestry degree. She is now a graduate student at Kyoto University, Japan.
Nicole (Werner) Landers 2007-2008
Nicole helped evaluate the susceptibility of sugar maple stands to defoliation by forest tent caterpillar (Malacosoma disstria Hübner) and the vulnerability to decline. She left this program to focus on entomological research.
Where is she now? Executive Director, Cornell University Cooperative Extension, Yates County
Sanae Kuwagaki, 2006-2008
Sanae was a master's student of Dr. Allan Drew. She used "Research Experience in Forest Ecosystem Science" to investigate the "Growth response of sugar maple and Norway maple seedlings to manganese in acidic conditions." She also helped other students with data collection, and bouncing around ideas.
Where is she now?
Adam Coates, 2006-2008
Adam worked on the first phase of the "Heartwood Project" from 2006-2008.
Where is he now? Pastor, West Asheville Vineyard Church, Asheville, NC
Oscar Abelleira Martinez, REU, summer 2003
Oscar worked with Melissa Lucash, on her doctoral project.
Where is he now? PhD Candidate, Joint Doctoral Program, College of Natural Resources, University of Idaho-IMoscow; CATIE, Turrialba, Costa Rica CV
Ryan Maher, 2002-2003
Ryan was one of the Agenda 2020 summer students.
Where is he now? I work for the USDA-Agricultural Research Service at the University of Minnesota (Minneapolis) as a research technician. Our focus is nitrogen cycling in cropping systems.
Olga Yakimenko, 2004
Dr: Yakimenko (sometimes spelled Iakimenko), Research Assistant, Moscow State University's Faculty of Soil Studies worked with our group spring, 2004, as part of MSU-SUNY Professional Fellows Program. She presented her work and participated in discussions connected with exchanges of biological field work of SUNY and MSU students.
Where is she now? Moscow State University (see her Fulbright page)
Where is he now? Deputy Director, International Co-operation, Korea Forest Service
Where is he now? Teacher and Cross Country Coach, Durango High School: Director, Colorado High Peaks Adventure Camps. He also still retains a few clients back east with his old company, Natresco Associates.
Xing Wang, MS, 2003
Stream water chemistry after a partial cutting in the Neversink River Basin, New York
A paired watershed technique was used to evaluate nutrient losses during the first year after a partial cutting from a small watershed in the Catskill Mountains of southern New York. The lower two third of the 10-ha treatment watershed (Block A) was harvested in February 2002 by a shelterwood method in which 60% of basal area was removed. A nearby 48-ha watershed was left as an uncut reference. Nitrate concentrations started to increase six months after the harvest and reached maximum values (above 100 μmol/L) of ten-fold over pre-harvest levels during the next two months. The concentrations of Ca, Mg and K were lower than pre-harvest values during the first growing season, but higher at high flows during the first dormant season when compared with pre-harvest levels. Total dissolved aluminum (Al to ) increased 4- to 8-fold above pre-harvest concentrations. The concentrations of NO 3 - and Al to remained above the reference concentrations throughout the first winter after cutting. Harvest effects on stream pH were insignificant. The partial cut resulted in measurable changes in stream water chemistry but the changes were much less than those previously observed after clearcutting of a nearby watershed, which demonstrated the role of residual trees in preventing hydrologic nutrient losses, especially during the growing season.
Wang, X., D.A. Burns, R.D. Yanai, R.D. Briggs, R.H. Germain. 2006. Changes in Stream Chemistry and Nutrient Export Following a Partial Harvest in the Catskill Mountains, New York, USA. For. Ecol. Manag. 223:103-112. PDF
Where is he now? Ph.D. student in Soil and Water Chemistry/Nutrient Management Department, University of Florida
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