Forest Sciences Commons^™

Nitrogen Addition Shapes Soil Phosphorus Availability In Two Reforested Tropical Forests In Southern China, Xiankai Lu, Jiangming Mo, Frank S. Gilliam, Hua Fang, Feifei Zhu, Yunting Fang, Wei Zhang, Juan Huang

Frank S. Gilliam

Scant information is available on how soil phosphorus (P) availability responds to atmospheric nitrogen (N) deposition, especially in the tropical zones. This study examined the effect of N addition on soil P availability, and compared this effect between forest sites of contrasting land-use history. Effects of N addition on soil properties, litterfall production, P release from decomposing litter, and soil P availability were studied in a disturbed (reforested pine forest with previous understory vegetation and litter harvesting) and a rehabilitated (reforested mixed pine/broadleaf forest with no understory vegetation and litter harvesting) tropical forest in southern China. Experimental N-treatments (above ambient) …

Interspecific Divergence In Foliar Nutrient Dynamics And Stem Growth In A Temperate Forest In Response To Chronic Nitrogen Inputs, Jeffrey D. May, Sarah Beth Burdette, Frank S. Gilliam, Mary Beth Adams

Jeffrey May

We studied the effects of excessive nitrogen (N) fertilization on foliar nutrient dynamics and stem growth in three important tree species in a mixed-deciduous forest. Stem diameter growth, foliar N concentrations, nitrogen–phosphorus (N/P) ratios, and nutrient resorption were determined for Acer rubrum L. (ACRU), Liriodendron tulipifera L. (LITU), and Prunus serotina Ehrh. (PRSE) on two 30-year-old watersheds at the Fernow Experimental Forest, West Virginia, USA: WS3, fertilized annually with 35 kg ammonium sulfate·ha^-1 since 1989, and WS7, an untreated control watershed. In an earlier (1992) study, foliar N concentrations of all three species averaged 11% higher in WS3 than …

Interspecific Divergence In Foliar Nutrient Dynamics And Stem Growth In A Temperate Forest In Response To Chronic Nitrogen Inputs, Jeffrey D. May, Sarah Beth Burdette, Frank S. Gilliam, Mary Beth Adams

Jeffrey May

We studied the effects of excessive nitrogen (N) fertilization on foliar nutrient dynamics and stem growth in three important tree species in a mixed-deciduous forest. Stem diameter growth, foliar N concentrations, nitrogen–phosphorus (N/P) ratios, and nutrient resorption were determined for Acer rubrum L. (ACRU), Liriodendron tulipifera L. (LITU), and Prunus serotina Ehrh. (PRSE) on two 30-year-old watersheds at the Fernow Experimental Forest, West Virginia, USA: WS3, fertilized annually with 35 kg ammonium sulfate ha–1 since 1989, and WS7, an untreated control watershed. In an earlier (1992) study, foliar N concentrations of all three species averaged 11% higher in WS3 than …

Interspecific Divergence In Foliar Nutrient Dynamics And Stem Growth In A Temperate Forest In Response To Chronic Nitrogen Inputs, Jeffrey D. May, Sarah Beth Burdette, Frank S. Gilliam, Mary Beth Adams

Frank S. Gilliam

We studied the effects of excessive nitrogen (N) fertilization on foliar nutrient dynamics and stem growth in three important tree species in a mixed-deciduous forest. Stem diameter growth, foliar N concentrations, nitrogen–phosphorus (N/P) ratios, and nutrient resorption were determined for Acer rubrum L. (ACRU), Liriodendron tulipifera L. (LITU), and Prunus serotina Ehrh. (PRSE) on two 30-year-old watersheds at the Fernow Experimental Forest, West Virginia, USA: WS3, fertilized annually with 35 kg ammonium sulfate·ha^-1 since 1989, and WS7, an untreated control watershed. In an earlier (1992) study, foliar N concentrations of all three species averaged 11% higher in WS3 than …

Long-Term Nitrogen Addition Decreases Carbon Leaching In A Nitrogen-Rich Forest Ecosystem, X. Lu, Frank S. Gilliam, G. Yu, H. Chen, J. Mo

Frank S. Gilliam

Dissolved organic carbon (DOC) plays a critical role in the carbon (C) cycle of forest soils, and has been recently connected with global increases in nitrogen (N) deposition. Most studies on effects of elevated N deposition on DOC have been carried out in N-limited temperate regions, with far fewer data available from N-rich ecosystems, especially in the context of chronically elevated N deposition. Furthermore, mechanisms for excess N-induced changes of DOC dynamics have been suggested to be different between the two kinds of ecosystems, because of the different ecosystem N status. The purpose of this study was to experimentally examine …

Interactive Effects Of Nitrogen And Phosphorus On Soil Microbial Communities In A Tropical Forest, Lei Liu, Tao Zhang, Frank S. Gilliam, Per Gundersen, Wei Zhang, Hao Chen, Jiangming Mo

Frank S. Gilliam

Elevated nitrogen (N) deposition in humid tropical regions may exacerbate phosphorus (P) deficiency in forests on highly weathered soils. However, it is not clear how P availability affects soil microbes and soil carbon (C), or how P processes interact with N deposition in tropical forests. We examined the effects of N and P additions on soil microbes and soil C pools in a N-saturated old-growth tropical forest in southern China to test the hypotheses that (1) N and P addition will have opposing effects on soil microbial biomass and activity, (2) N and P addition will alter the composition of …

Estimated Losses Of Plant Biodiversity Across The U.S. From Historical N Deposition From 1985—2010., Christopher M. Clark, Philip E. Morefield, Frank S. Gilliam, Linda H. Pardo

Frank S. Gilliam

Although nitrogen (N) deposition is a significant threat to herbaceous plant biodiversity worldwide, it is not a new stressor for many developed regions. Only recently has it become possible to estimate historical impacts nationally for the United States. We used 26 years (1985–2010) of deposition data, with ecosystem-specific functional responses from local field experiments and a national critical loads (CL) database, to generate scenario-based estimates of herbaceous species loss. Here we show that, in scenarios using the low end of the CL range, N deposition exceeded critical loads over 0.38, 6.5, 13.1, 88.6, and 222.1 million ha for the Mediterranean …

Variation In Vegetation And Microbial Linkages With Slope Aspect In A Montane Temperate Hardwood Forest, Frank S. Gilliam, Radim Hedl, Marketa Chudomelova, Rebecca L. Mcculley, Jim Nelson

Frank S. Gilliam

Plant ecologists have long been interested in aspect-related contrasts of montane forests. Few studies have assessed correlation (linkage) among vegetation strata; fewer have included soil microbial communities. This study assessed contrasts in overstory, spring herbaceous, and soil microbial communities between northeast (NE) - and southwest (SW) -facing slopes in a second-growth West Virginia hardwood forest. We addressed three questions: (1) how do soil microbial, herbaceous layer, and overstory communities vary with slope aspect? (2) do forest vegetation strata and soil microbial communities exhibit linkage? (3) do biotic relationships and linkage vary with slope aspect? Moisture, organic matter, pH, soil NO3-, …

Changes In Soil Carbon Sequestration In Pinus Massoniana Forests Along An Urban-To-Rural Gradient Of Southern China, H. Chen, W. Zhang, Frank S. Gilliam, L. Liu, J. Huang, T. Zhang, W. Wang, J. Mo

Frank S. Gilliam

Urbanization is accelerating globally, causing a variety of environmental changes such as increases in air temperature, precipitation, atmospheric CO2, and nitrogen (N) deposition. However, the effects of these changes on forest soil carbon (C) sequestration remain largely unclear. Here, we used urban-to-rural environmental gradients in Guangdong Province, southern China, to address the potential effects of these environmental changes on soil C sequestration in Pinus massoniana forests. In contrast to our expectations and earlier observations, soil C content in urban sites was significantly lower than that in suburban and rural sites. Lower soil C pools in urban sites were correlated with …

In Situ Nitrogen Mineralization, Nitrification, And Ammonia Volatilization In Maize Field Fertilized With Urea In Huanghuaihai Region Of Northern China, Xuelin Zhang, Qun Wang, Jun Xu, Frank S. Gilliam, Nicolas Tremblay, Chaohai Li

Frank S. Gilliam

Nitrogen (N) fertilization potentially affects soil N mineralization and leaching, and can enhance NH3 volatilization, thus impacting crop production. A fertilizer experiment with five levels of N addition (0, 79, 147, 215 and 375 kg N ha-1) was performed in 2009 and 2010 in a maize field in Huanghuaihai region, China, where > 300 kg N ha-1 has been routinely applied to soil during maize growth period of 120 days. Responses of net N mineralization, inorganic N flux (0–10cm), NH3 volatilization, and maize yield to N fertilization were measured. During the growth period, net N mineralization and nitrification varied seasonally, with …

Spatial Variation In Carbon And Nitrogen In Cultivated Soils In Henan Province, China: Potential Effect On Crop Yield, Xuelin Zhang, Qun Wang, Frank S. Gilliam, Yilun Wang, Feina Cha, Chaohai Li

Frank S. Gilliam

Improved management of soil carbon (C) and nitrogen (N) storage in agro-ecosystems represents an important strategy for ensuring food security and sustainable agricultural development in China. Accurate estimates of the distribution of soil C and N stores and their relationship to crop yield are crucial to developing appropriate cropland management policies. The current study examined the spatial variation of soil organic C (SOC), total soil N (TSN), and associated variables in the surface layer (0–40 cm) of soils from intensive agricultural systems in 19 counties within Henan Province, China, and compared these patterns with crop yield. Mean soil C and …

Nutrient Limitation In Three Lowland Tropical Forests In Southern China Receiving High Nitrogen Deposition: Insights From Fine Root Responses To Nutrient Additions, Feifei Zhu, Muneoki Yoh, Frank S. Gilliam, Xiankai Lu, Jiangming Mo

Frank S. Gilliam

Elevated nitrogen (N) deposition to tropical forests may accelerate ecosystem phosphorus (P) limitation. This study examined responses of fine root biomass, nutrient concentrations, and acid phosphatase activity (APA) of bulk soil to five years of N and P additions in one old-growth and two younger lowland tropical forests in southern China. The old-growth forest had higher N capital than the two younger forests from long-term N accumulation. From February 2007 to July 2012, four experimental treatments were established at the following levels: Control, N-addition (150 kg N ha–1 yr–1), P-addition (150 kg P ha–1 yr–1) and N+P-addition (150 kg N …

Spatial Variation In Carbon And Nitrogen In Cultivated Soils In Henan Province, China: Potential Effect On Crop Yield, Xuelin Zhang, Qun Wang, Frank S. Gilliam, Yilun Wang, Feina Cha, Chaohai Li

Frank S. Gilliam

Improved management of soil carbon (C) and nitrogen (N) storage in agro-ecosystems represents an important strategy for ensuring food security and sustainable agricultural development in China. Accurate estimates of the distribution of soil C and N stores and their relationship to crop yield are crucial to developing appropriate cropland management policies. The current study examined the spatial variation of soil organic C (SOC), total soil N (TSN), and associated variables in the surface layer (0–40 cm) of soils from intensive agricultural systems in 19 counties within Henan Province, China, and compared these patterns with crop yield. Mean soil C and …

Nutrient Limitation In Three Lowland Tropical Forests In Southern China Receiving High Nitrogen Deposition: Insights From Fine Root Responses To Nutrient Additions, Feifei Zhu, Muneoki Yoh, Frank S. Gilliam, Xiankai Lu, Jiangming Mo

Frank S. Gilliam

Elevated nitrogen (N) deposition to tropical forests may accelerate ecosystem phosphorus (P) limitation. This study examined responses of fine root biomass, nutrient concentrations, and acid phosphatase activity (APA) of bulk soil to five years of N and P additions in one old-growth and two younger lowland tropical forests in southern China. The old-growth forest had higher N capital than the two younger forests from long-term N accumulation. From February 2007 to July 2012, four experimental treatments were established at the following levels: Control, N-addition (150 kg N ha–1 yr–1), P-addition (150 kg P ha–1 yr–1) and N+P-addition (150 kg N …

In Situ Nitrogen Mineralization, Nitrification, And Ammonia Volatilization In Maize Field Fertilized With Urea In Huanghuaihai Region Of Northern China, Xuelin Zhang, Qun Wang, Jun Xu, Frank S. Gilliam, Nicolas Tremblay, Chaohai Li

Frank S. Gilliam

Nitrogen (N) fertilization potentially affects soil N mineralization and leaching, and can enhance NH3 volatilization, thus impacting crop production. A fertilizer experiment with five levels of N addition (0, 79, 147, 215 and 375 kg N ha-1) was performed in 2009 and 2010 in a maize field in Huanghuaihai region, China, where > 300 kg N ha-1 has been routinely applied to soil during maize growth period of 120 days. Responses of net N mineralization, inorganic N flux (0–10cm), NH3 volatilization, and maize yield to N fertilization were measured. During the growth period, net N mineralization and nitrification varied seasonally, with …

Using Plant Functional Attributes To Quantify Site Productivity And Growth Patterns In Mixed Forests, Jerome K. Vanclay, A N. Gillison, Rod J. Keenan

Professor Jerome K Vanclay

Forest growth models are one of several important prerequisites for sustainable management. The complexity of tropical moist forest means that there is often little objective information to classify sites and species for growth modelling and yield prediction. Classification based on observable morphological characteristics may be a useful surrogate for, or supplement to other alternatives. This study investigated the utility of plant functional attributes (PFAs) for site and species classification. PFAs describe a plant in terms of its photosynthetic and vascular support system, and the sum of individual PFAs for all species on a plot provides an efficient summary of vegetation …

Compatible Deterministic And Stochastic Predictions By Probabilistic Modelling Of Individual Trees, Jerome K. Vanclay

Professor Jerome K Vanclay

A single growth model can provide both deterministic and stochastic predictions which are compatible. Change may be expressed using probabilistic functions which can represent proportions of populations or probabilities for individuals. The former represents determinism while the latter enables the stochastic implementation. The same functional relationships may thus be used to generate compatible deterministic and stochastic predictions. All components of forest growth and change, including diameter increment, can be expressed as probabilistic functions, enabling construction of a single model which provides compatible stochastic and deterministic outcomes. Users may specify the minimum expansion factor corresponding to the simulated plot size and …

Environmental Forcing Does Not Induce Diel Or Synoptic Variation In The Carbon Isotope Content Of Forest Soil Respiration, Steven J. Hall, D. R. Bowling, J. E. Egan

Steven J. Hall

Recent studies have examined temporal fluctuations in the amount and carbon isotope content (δ13C) of CO2 produced by the respiration of roots and soil organisms. These changes have been correlated with diel cycles of environmental forcing (e.g., sunlight and soil temperature) and with synoptic-scale atmospheric motion (e.g., rain events and pressure-induced ventilation). We used an extensive suite of measurements to examine soil respiration over 2 months in a subalpine forest in Colorado, USA (the Niwot Ridge AmeriFlux forest). Observations included automated measurements of CO2 and δ13C of CO2 in the soil efflux, the soil gas profile, and forest air. There …

Changes In Plant Species Composition And Structure In Two Peri-Urban Nature Preserves Over 10 Years, Rebecca W. Dolan, Jessica D. Stepens, Marcia E. Moore

Rebecca W. Dolan

Peri-urban natural areas, at the boundaries of cities and adjacent agricultural/rural land, are subject to ecological threats endemic to both land use types. We used permanent plots to document changes in habitat quality by monitoring herbaceous-layer plant species presence and cover over a decade (1996/97 and 2007) in two peri-urban nature preserves in central Indiana, U.S.A. The preserves are comprised of different forest community types: wet-mesic depressional forest and mesic upland forest. Habitat characteristics, based on Floristic Quality Assessment parameters, showed only a single change for either preserve between survey years: wetness values were lower in the wet-mesic depressional site …

Assessing The Urban Forest Values An Institutional Sector Approach, Anthony M. Rodriguez Ph.D.

Anthony M Rodriguez Ph.D.

The presentation is an aspect of an ongoing study that demonstrates and maps the urban forest values. Using ARCGIS the paper will model social change and the potential for expanding or not the natural environment focusing on the values and the projected change based on the sectors position in reference to sustainability and more specifically the urban forest as an artifact to foster positive spatial change.

Two Hundred Years Of Forest Change: Effects Of Urbanization On Tree Species Composition And Structure, Rebecca W. Dolan

Rebecca W. Dolan

Despite their importance, the dynamics of urban floras are not well understood and quantitative historical data are rare. The current study used three data sets for trees in Indianapolis/Marion County, Indiana, U.S., to document change over 200 years to the original beech-maple forest and to examine future implications of contemporary tree planting efforts in light of these changes. Data on tree composition and size collected before significant settlement in the early 1800s are compared with recent surveys of trees in remnant natural areas and with trees found on city streets and rights-of-way. All the species recorded in historical surveys are …

Lignin Decomposition Is Sustained Under Fluctuating Redox Conditions In Humid Tropical Forest Soils, Steven J. Hall, Whendee L. Silver, Vitaliy I. Timokhin, Kenneth E. Hammel

Steven J. Hall

Lignin mineralization represents a critical flux in the terrestrial carbon (C) cycle, yet little is known about mechanisms and environmental factors controlling lignin breakdown in mineral soils. Hypoxia is thought to suppress lignin decomposition, yet potential effects of oxygen (O2) variability in surface soils have not been explored. Here, we tested the impact of redox fluctuations on lignin breakdown in humid tropical forest soils during ten-week laboratory incubations. We used synthetic lignins labeled with 13C in either of two positions (aromatic methoxyl or propyl side chain Cb) to provide highly sensitive and specific measures of lignin mineralization seldom employed in …

Improving Alternate Lignin Catabolite Utilization Of Ligab From Sphingobium Sp. Strain Syk-6 Through Site Directed Mutagenesis, Kevin P. Barry, Erin F. Cohn, Abraham Ngu, Erika A. Taylor

Erika A. Taylor, Ph.D.

Protocatechuate 4,5-dioxygenase (LigAB) catalyzes dioxygenation of multiple lignin derived aromatic compounds—such as protocatechuate (PCA), gallate (GA) and 3-O-methyl gallate (3OMG)—with decreasing proficiency as the molecule size increases. We predicted that phenylalanine-103 of the α subunit (Phe103α) controls substrate specificity through interaction with the C5-funtionality of bound substrates, and mutagenesis would enhance GA and 3OMG catalysis. LigAB with Phe103α mutations (F103 V, F103T and F103H) displayed enhanced catalytic efficiency for dioxygenation of 3OMG, with mutants displaying 12- to 31-fold increases in View the MathML source, making these mutant enzymes more active with 3OMG than its native dioxygenase (DesZ). The F103T and …

Annual Brome Biocontrol After Wildfire Using A Native Fungal Seed Pathogen, Susan E. Meyer, Phil S. Allen, Julie Beckstead, Michael Gregg, Heidi Newsome, Kathleen Harcksen, Gary Kidd, Glenn Paulsen, Karen Prentice, Dana Quinney, David Wilderman, Stephanie Carlson, Suzette Clement, Duane Smith, Thom Stewart, Katie Merrill, Keith Merrill, Kedra Foote, Stephen Harrison, Kelly Bergen, Brian Connelly, Trevor Davis, Sandra Dooley, Michael Huck, Laura Street, Lauren Miller

Benjamin L. Harwood

A major problem in post-fire restoration of semi-arid shrublands dominated by annual bromes is the presence of carryover seed banks that cannot be controlled using conventional methods. These seeds can provide significant competition for seeded species in the years following treatment. We investigated the feasibility of using a naturally occurring seed pathogen, the ascomycete Pyrenophora semeniperda, as a biocontrol organism for eliminating this carryover seed bank. We carried out the necessary technology development to create and apply field inoculum to cheatgrass- or red brome-infested areas (both burned and unburned) at six sites located in three states across two years of …

Breeding System And Sex Ratio Variation In Mulberries (Morus, Moraceae), Madhav Nepal

Madhav Nepal

Overstory Dynamics In An Uncut Pine-Hardwood Stand: Lessons From Seventy Years Of Passive Management, Don Bragg, Michael G. Shelton

Michael Shelton

Long-term demonstration projects on experimental forests can be adapted from their original goals to provide insights into contemporary research questions. For instance, a 32.4-hectare cutover parcel on the Crossett Experimental Forest, the eventual Reynolds Research Natural Area (RRNA), was reserved in 1936 to act as a control for more intensively managed study areas. Over the last 70+ years, the RRNA has been allow to develop under 'natural' conditions that include no harvesting or other human interventions-with the notable exception of fire control. From 1937 until the most recent measurement in 2007, overall stand basal increased from about 20 to 36 …

Large Fluxes And Rapid Turnover Of Mineral-Associated Carbon Across Topographic Gradients In A Humid Tropical Forest: Insights From Paired 14c Analysis, Steven J. Hall, G. Mcnicol, T. Natake, W. L. Silver

Steven J. Hall

It has been proposed that the large soil carbon (C) stocks of humid tropical forests result predominantly from C stabilization by reactive minerals, whereas oxygen (O2) limitation of decomposition has received much less attention. We examined the importance of these factors in explaining patterns of C stocks and turnover in the Luquillo Experimental Forest, Puerto Rico, using radiocarbon (14C) measurements of contemporary and archived samples. Samples from ridge, slope, and valley positions spanned three soil orders (Ultisol, Oxisol, Inceptisol) representative of humid tropical forests, and differed in texture, reactive metal content, O2 availability, and root biomass. Mineral-associated C comprised the …

Tb178: Methods For Evaluating Carbon Fractions In Forest Soils: A Review, Jennifer L. Evans, Ivan J. Fernandez, Lindsey E. Rustad, Stephen A. Norton

Ivan J. Fernandez

This publication was developed as part of an effort to evaluate the existing methodologies for determining carbon fractions in soils that might be applied to the question of forest soil C sequestration. A great deal of research has been done on this topic although often focused on agronomic soils. Forest land managers will be increasingly interested in identifying methods to monitor and to evaluate the effects of forest practices on soil C reserves. As well researchers are interested in this and the logical linkages to N cycling. Ultimately practical methods that can be widely utilized will be needed; these may …

Tb196: Temperature, Soil Moisture, And Streamflow At The Bear Brook Watershed In Maine (Bbwm), Ivan J. Fernandez, Joseph E. Karem, Stephen A. Norton, Lindsey E. Rustad

Ivan J. Fernandez

The Bear Brook Watershed in Maine is a whole-ecosystem chemical manipulation initiated in 1987 to study the effects of acid deposition on forests and surface waters. The focus of this research was to understand the biogeochemical response of watersheds with emphasis on chemistry and hydrology. In 2001 a program was initiated to provide more detailed measurements of temperature and moisture to examine critical linkages amongst chemical, biological, and physical processes that ultimately work together to define ecosystem function. The purpose of this publication is to provide data from the initial phase of soil temperature, air temperature, and soil moisture measurements …

Tb162: Red Maple And White Pine Litter Quality: Initial Changes With Decomposition, Mairin T. Delaney, Ivan J. Fernandez, Jeffrey A. Simmons, Russel D. Briggs

Ivan J. Fernandez

The specific objectives of this study were (a) to define the organic and inorganic composition of foliar litter from red maple (Acer rubrum L.) and white pine (Pinus strobus L.), and (b) to determine the shifts in the organic and inorganic composition of these two litter types during the initial stages of decomposition. These two species were chosen because of their prominence in the northeastern U.S. and the contrast they afforded in litter quality characteristics which have a strong influence on litter decomposition.