Article
Ornithology
Kimberly A. A. Lato, Lesley H. H. Thorne
Summary: Anticoagulants like sodium heparin are commonly added to avian blood samples, but their effects on stable isotope studies are not well understood. This study assessed the effects of sodium heparin on stable isotope values in avian blood and found that it only significantly affected the S-34 values, with minimal impact on diet proportion estimation. Researchers should be cautious of the potential impacts of sodium heparin on stable isotope values in avian blood, especially for S-34, and consider the study scale and species characteristics.
Article
Microbiology
Carmen Alicia Rivera Perez, Dennis Janz, Dominik Schneider, Rolf Daniel, Andrea Polle
Summary: This study investigated the responses of the fungal community and the host tree to fluctuations in nitrogen availability. The results showed that the fungi displayed resistance to increased nitrogen levels, while the tree dynamically metabolized the supplied nitrogen sources.
Article
Agronomy
Spencer M. Heuchan, Claudia Wagner-Riddle, Khagendra R. Baral, Katelyn A. Congreves, Richard E. Farrell, Sean Jordan, Hugh A. L. Henry
Summary: The study found that cover crops can effectively increase nitrogen retention, especially in the belowground N pool. In the cover crop treatments, 25% more nitrogen was recovered compared to the control group, and spring termination of red clover resulted in the highest belowground nitrogen retention.
Article
Ecology
William A. Argiroff, Donald R. Zak, Peter T. Pellitier, Rima A. Upchurch, Julia P. Belke
Summary: The study reveals that ectomycorrhizal fungi with peroxidases decrease with increasing inorganic nitrogen availability in northern temperate forests, while ligninolytic fungal saprotrophs show no response. Soil organic matter and soil carbon are negatively correlated with ECM fungi with peroxidases and positively correlated with inorganic nitrogen availability, indicating that these ECM fungi contribute to the decay of lignin-derived soil organic matter and reduce soil carbon storage. The correlations observed suggest a tradeoff between tree nitrogen nutrition and ECM composition, influencing soil organic matter dynamics in temperate forests.
Article
Microbiology
Tao Wang, Per Persson, Anders Tunlid
Summary: The study found that ectomycorrhizal fungi can access nitrogen from mineral-associated proteins, a mechanism that is shared among multiple fungal lineages and exploration types.
ENVIRONMENTAL MICROBIOLOGY
(2021)
Article
Ecology
Cecilia M. Prada, Benjamin L. Turner, James W. Dalling
Summary: The differences in nutrient acquisition pathways between arbuscular mycorrhizal (AM) and ectomycorrhizal (EM) fungi may influence seedling growth and nitrogen availability in montane forests of Central America.
FUNCTIONAL ECOLOGY
(2022)
Article
Biodiversity Conservation
Joseph E. Carrara, Christopher A. Walter, Zachary B. Freedman, Ashley N. Hostetler, Jennifer S. Hawkins, Ivan J. Fernandez, Edward R. Brzostek
Summary: As nitrogen deposition increases, forest soils dominated by trees that associate with ectomycorrhizal fungi store more carbon compared to those dominated by trees associating with arbuscular mycorrhizae. This difference is likely due to unique nutrient cycling responses to nitrogen between the two types of mycorrhizal soils.
GLOBAL CHANGE BIOLOGY
(2021)
Article
Agronomy
Mubarak Mahmud, Tania L. Maxwell, Sixtine Cueff, Romain Schroeder, Stephane Bazot, Nicolas Delpierre, Anne Marmagne, Gaelle Vincent, Laure Barthes
Summary: This study quantified the distribution of nitrogen, dry-matter, and soil-applied (15)N in different compartments of five naturally-growing oak trees. The results showed that the xylem rings compartment contained the most biomass, while branches and coarse roots contained the most nitrogen. The labeled (15)N was found in all compartments except the heartwood, with the majority being in the leaves. Overlooked compartments such as coarse roots, stumps, xylem, and other branches accounted for a significant portion of the (15)N recovery. The study also revealed that (15)N was present in all sapwood rings, with more being found in younger rings compared to older ones. The (15)N allocated to ancient rings could originate from various sources, including direct uptake from the soil, autumnal resorption from leaves, or transport through ray parenchyma. Additionally, the study confirmed the role of microbial biomass as a nitrogen sink in forests.
Article
Agronomy
Erik A. Hobbie, Rolf Siegwolf, Christian Koerner, Katharina Steinmann, Markus Wilhelm, Matthias Saurer, Sonja G. Keel
Summary: In a Swiss forest, the spatial and temporal dynamics of carbon transfer from tree hosts to ectomycorrhizal fungi were studied. The results showed that fungal morphology did not affect carbon transfer, and carbohydrates were the primary form of carbon transferred to sporocarps across different zones. Environmental factors such as solar radiation and drought influenced carbon transfer.
Article
Biochemistry & Molecular Biology
Long Peng, Yan Zhang, Irina S. Druzhinina, Christian P. Kubicek, Yuchen Wang, Zhiyong Zhu, Yuwei Zhang, Kexuan Wang, Zhuo Liu, Xiaoguo Zhang, Francis Martin, Zhilin Yuan
Summary: Increasing nitrogen deposition negatively affects belowground ectomycorrhizal networks. The root-associated fungus Clitopilus hobsonii establishes a symbiotic relationship with Populus tomentosa, which is favored by organic nitrogen over mineral nitrogen. The symbiosis promotes plant growth and enhances the transfer of nitrogen from the fungus to the plant. The fungus has a dual lifestyle and its nutritional mutualism is affected by ammonium and nitrate, resulting in physiological remodeling.
Article
Ecology
Georgia S. Seyfried, Adriana Corrales, Angela D. Kent, James W. Dalling, Wendy H. Yang
Summary: The intrinsic soil properties play a mediating role in the effects of ectomycorrhizal fungi on soil organic matter and nitrogen cycling. This study explores the potential role of fungal communities in driving the observed variation in ectomycorrhizal effects. The results suggest the influence of soil pH and fertility in mediating fungal community contributions to the variation in ectomycorrhizal effects.
Article
Plant Sciences
Monica Sebastiana, Susana Serrazina, Filipa Monteiro, Daniel Wipf, Jerome Fromentin, Rita Teixeira, Rui Malho, Pierre-Emmanuel Courty
Summary: This study aimed to evaluate the nitrogen metabolic response of oak plants when inoculated with the ectomycorrhizal fungus Pisolithus tinctorius. The expression of candidate genes encoding proteins involved in nitrogen uptake and assimilation was investigated in ectomycorrhizal roots. The findings suggest that inorganic nitrogen is the main form of nitrogen transferred by the symbiotic fungus into the roots of the host plant.
Article
Plant Sciences
Sun Pengfei, Shen Yafei, Wang Lijun, Chen Tian, Zhang Meng, Xiao Wenfa, Cheng Ruimei
Summary: The allocation of photosynthetic products in Pinus massoniana was affected by nitrogen addition and mycorrhizal symbiosis, with an optimal nitrogen addition concentration of 60 kg N hm(-1) a(-1). Mycorrhizal symbiosis expanded the absorption area of plant roots, promoting growth.
FRONTIERS IN PLANT SCIENCE
(2022)
Article
Soil Science
Wanji Guo, Junxiang Ding, Qitong Wang, Mingzhen Yin, Xiaomin Zhu, Qing Liu, Ziliang Zhang, Huajun Yin
Summary: The study conducted N fertilization experiments in alpine forests on the eastern Tibetan Plateau, finding that nitrogen addition promoted mycelial growth in some tree species but repressed it in others, indicating diverse responses of mycelial dynamics to nitrogen deposition based on native soil nutrient availability.
SOIL BIOLOGY & BIOCHEMISTRY
(2021)
Article
Microbiology
Nan Yang, Bo Wang, Dong Liu, Xuan Wang, Xiuxiu Li, Yan Zhang, Yaming Xu, Sili Peng, Zhiwei Ge, Lingfeng Mao, Honghua Ruan, Rodica Pena
Summary: The continuous increase in soil nitrogen has strong impacts on ecosystems. Understanding how plant ectomycorrhizal fungi respond to additional nitrogen can help develop and implement effective management strategies. A study in a poplar plantation in China showed that excessive nitrogen reduced EMF colonization and species richness, affecting community structure and functional traits. Soil carbon content and available phosphorus were important factors driving EMF abundance, while ammonium content influenced community structure and mycelium foraging types.
Article
Environmental Sciences
Qian Zhao, Allison M. Thompson, Stephen J. Callister, Malak M. Tfaily, Sheryl L. Bell, Sarah E. Hobbie, Kirsten S. Hofmockel
Summary: This study conducted an 8-month aerobic incubation experiment using grassland soils, revealing that the persistence of labile compounds varied under different soil mineralogy conditions, while the richness of more complex organic molecules increased in most cases. The study also demonstrated that N addition decreased soil respiration and inhibited the convergence of SOM chemistry across diverse grassland ecosystems.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Environmental Sciences
Emily B. Graham, Kirsten S. Hofmockel
Summary: Coupled biogeochemical cycles play a crucial role in ecosystem ecology, influencing behaviors at individual and community scales. Developing process-based models that accurately capture these dynamics, especially in SOM decomposition, remains a challenge. Ecological stoichiometry offers a framework for merging biogeochemical and microbiological models and advancing omics-enabled biogeochemical models. Collaboration and exchange of information between high-resolution investigations and large-scale models is essential for refining objectives and specifying dynamics in the field of SOM decomposition modeling.
Article
Biodiversity Conservation
Adrienne B. Keller, Elizabeth T. Borer, Scott L. Collins, Lang C. DeLancey, Philip A. Fay, Kirsten S. Hofmockel, Andrew D. B. Leakey, Melanie A. Mayes, Eric W. Seabloom, Christopher A. Walter, Yong Wang, Qian Zhao, Sarah E. Hobbie
Summary: Nutrient addition experiments have shown that changes in soil carbon and nitrogen pools are influenced by nutrient amendments, with varying effects. Differences in soil carbon and nitrogen pool sizes among sites varied greatly, with moisture index, plant productivity, soil texture, and mineralogy as key predictors of cross-site soil carbon. Protecting highly productive temperate grasslands is crucial for reducing future greenhouse gas emissions from land use change.
GLOBAL CHANGE BIOLOGY
(2022)
Article
Biotechnology & Applied Microbiology
Darian N. Smercina, Young-Mo Kim, Mary S. Lipton, Dusan Velickovic, Kirsten S. Hofmockel
Summary: Free-living nitrogen-fixing bacteria significantly contribute to terrestrial nitrogen availability, but the forms of nitrogen they contribute are not well understood. Studying soil microorganisms in situ poses challenges due to differences in scale and complexities of the soil system. Our study focused on microorganisms and microbial-scale processes to better understand the nitrogen sources and process rates of nitrogen fixation. We characterized the production of nitrogen-containing metabolites by two common soil bacteria under different growth conditions and found that nitrogen contributions from nitrogen fixation occur in multiple forms. Our findings also highlight the influence of environmental structure and sampling scale on microbial activity. Quantifying microbial-scale processes is crucial for upscaling ecosystem function.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2022)
Review
Environmental Sciences
Cecelia M. Gerstenbacher, Adrien C. Finzi, Randi D. Rotjan, Alyssa B. Novak
Summary: Microplastics have potential impacts on seagrass plants, epiphytes, and sediment processes and functions. They may harm seagrasses and epiphytes through impalement and light/gas blockage, increase toxin concentrations, and disrupt nutrient cycling and sediment characteristics.
ENVIRONMENTAL POLLUTION
(2022)
Article
Plant Sciences
Allison L. Gill, Peter B. Adler, Elizabeth T. Borer, Christopher R. Buyarski, Elsa E. Cleland, Carla M. D'Antonio, Kendi F. Davies, Daniel S. Gruner, W. Stanley Harpole, Kirsten S. Hofmockel, Andrew S. MacDougall, Rebecca L. McCulley, Brett A. Melbourne, Joslin L. Moore, John W. Morgan, Anita C. Risch, Martin Schutz, Eric W. Seabloom, Justin P. Wright, Louie H. Yang, Sarah E. Hobbie
Summary: This study found that nitrogen can accelerate early-stage decomposition of above-ground plant litter in temperate grasslands, but slow down late-stage decomposition. These findings have important implications for the effects of nitrogen on soil organic matter formation.
JOURNAL OF ECOLOGY
(2022)
Article
Microbiology
Darian Smercina, Neerja Zambare, Kirsten Hofmockel, Natalie Sadler, Erin L. Bredeweg, Carrie Nicora, Lye Meng Markillie, Jayde Aufrecht
Summary: Researchers have developed Synthetic Soil Aggregates (SSAs) to simulate natural soil characteristics and provide a transparent cultivation method for studying microbial processes. SSAs can assist researchers in quantifying microbial scale processes and obtaining high-resolution data.
Article
Cell Biology
Brayon J. Fremin, Ami S. Bhatt, Nikos C. Kyrpides
Summary: This study used a large-scale comparative genomics approach to discover that small genes are more prevalent in phage genomes than in host prokaryotic genomes. These small genes may have important functions, such as encoding anti-CRISPR proteins and antimicrobial proteins.
Article
Ecology
Adrienne B. B. Keller, Christopher A. A. Walter, Dana M. M. Blumenthal, Elizabeth T. T. Borer, Scott L. L. Collins, Lang C. C. DeLancey, Philip A. A. Fay, Kirsten S. S. Hofmockel, Johannes M. H. Knops, Andrew D. B. Leakey, Melanie A. A. Mayes, Eric W. W. Seabloom, Sarah E. E. Hobbie
Summary: Increased nutrient inputs from anthropogenic activities are expected to enhance primary productivity in terrestrial ecosystems. However, changes in allocation between aboveground and belowground areas in response to nutrient additions have different effects on soil carbon storage. Roots play a major role in soil carbon storage, therefore understanding belowground net primary productivity (BNPP) and biomass responses to changes in nutrient availability is crucial for predicting carbon-climate feedbacks.
Article
Multidisciplinary Sciences
Ruonan Wu, Clyde A. Smith, Garry W. Buchko, Ian K. Blaby, David Paez-Espino, Nikos C. Kyrpides, Yasuo Yoshikuni, Jason E. McDermott, Kirsten S. Hofmockel, John R. Cort, Janet K. Jansson
Summary: Metagenomics has revealed the presence of auxiliary metabolic genes (AMGs) in soil viral genomes, and this study provides evidence that these AMGs actually produce functional proteins that can metabolize chitin. The crystal structure of a soil viral AMG product, which exhibits chitosanase activity, has been determined, providing insights into substrate specificity and enzyme mechanism. These findings support the idea that soil viruses contribute auxiliary functions to their hosts.
NATURE COMMUNICATIONS
(2022)
Article
Ecology
Bram W. G. Stone, Paul Dijkstra, Brianna K. K. Finley, Raina Fitzpatrick, Megan M. M. Foley, Michaela Hayer, Kirsten S. S. Hofmockel, Benjamin J. J. Koch, Junhui Li, Xiao Jun A. Liu, Ayla Martinez, Rebecca L. L. Mau, Jane Marks, Victoria Monsaint-Queeney, Ember M. M. Morrissey, Jeffrey Propster, Jennifer Pett-Ridge, Alicia M. M. Purcell, Egbert Schwartz, Bruce A. A. Hungate
Summary: The study explores the usage of life history strategies to predict the performance of microorganisms in nature. By applying the copiotroph-oligotroph framework, the study examines if it can forecast the population growth rate of bacterial taxa in different ecosystems. The results show that it is difficult to generalize bacterial life history strategies to broad lineages, and there is a need for direct measurement of microbial communities in soil to advance ecologically realistic frameworks.
Article
Biochemistry & Molecular Biology
Christopher P. Kasanke, Qian Zhao, Trinidad Alfaro, Christopher A. Walter, Sarah E. Hobbie, Tanya E. Cheeke, Kirsten S. Hofmockel
Summary: Nutrient exchange between land plants and AM fungi is based on symbiosis, and environmental factors and nutrient addition have important impacts on the distribution patterns of AM fungi. Our study found that ecosystem type, rather than nutrient treatment, is the main driver of AM fungal colonization, diversity, and community composition. This research provides evidence for the importance of long-term, large scale studies in understanding nutrient addition effects and ecological context.
Article
Ecology
Melannie D. Hartman, Mark Burnham, William J. Parton, Adrien Finzi, Evan H. DeLucia, Wendy H. Yang
Summary: This study used a modeling approach to evaluate the effectiveness of nitrification suppression by sorghum in reducing N2O emissions and nitrate leaching in an energy sorghum/soybean rotation. The results showed that nitrification suppression had a modest effect on reducing N2O emissions, but had little impact on nitrate leaching. Altering the timing of fertilizer applications to synchronize with high soil ammonium levels had mixed effects on N losses. Increasing N retention during the non-growing season may be more effective for reducing annual N losses in the rainfed Midwest.
Article
Microbiology
Katherine I. Naasko, Daniel Naylor, Emily B. Graham, Sneha P. Couvillion, Robert Danczak, Nikola Tolic, Carrie Nicora, Steven Fransen, Haiying Tao, Kirsten S. Hofmockel, Janet K. Jansson
Summary: Climate change leads to increased drought and loss of soil organic carbon. Calcareous soils can help mitigate these losses. This study examined the impact of irrigation and perennial plants on deep soil carbon chemistry in an unfertilized calcareous soil. The results showed that soil microbial community composition was more affected by irrigation and plant cover, while metabolomes, lipidomes, and proteomes varied with soil depth.
Article
Ecology
Jeth Walkup, Chansotheary Dang, Rebecca L. Mau, Michaela Hayer, Egbert Schwartz, Bram W. Stone, Kirsten S. Hofmockel, Benjamin J. Koch, Alicia M. Purcell, Jennifer Pett-Ridge, Chao Wang, Bruce A. Hungate, Ember M. Morrissey
Summary: By studying the growth rates of soil bacteria, we found that the order-genus of bacterial strains could predict their growth rates and explain an average of 31% and up to 58% of the variation in growth rates within ecosystems. Despite limited overlap in community composition across ecosystems, shared nodes in the phylogeny enabled ancestral trait reconstruction and cross-ecosystem predictions. Our results suggest that shared evolutionary history contributes to similarity in the relative growth rates of related bacteria, allowing phylogeny-based predictions to explain a substantial amount of the variation in taxon-specific functional traits, within and across ecosystems.
ISME COMMUNICATIONS
(2023)
