In the northern hemisphere, boreal forests are a major source of biogenic volatile organic compounds (BVOCs), which drive atmospheric processes and lead to cloud formation and changes in the Earth's radiation budget. Although forest vegetation is known to be a significant source of BVOCs, the role of soil and the forest floor, and especially interannual variations in fluxes, remains largely unknown due to a lack of long-term measurements. Our aim was to determine the interannual, seasonal and diurnal dynamics of boreal forest floor volatile organic compound (VOC) fluxes and to estimate how much they contribute to ecosystem VOC fluxes. We present here an 8-year data set of forest floor VOC fluxes, measured with three automated chambers connected to the quadrupole proton transfer reaction mass spectrometer (quadrupole PTR-MS). The exceptionally long data set shows that forest floor fluxes were dominated by monoterpenes and methanol, with relatively comparable emission rates between the years. Weekly mean monoterpene fluxes from the forest floor were highest in spring and in autumn (maximum 59 and 86 μg m h, respectively), whereas the oxygenated VOC fluxes such as methanol had highest weekly mean fluxes in spring and summer (maximum 24 and 79 μg m h, respectively). Although the chamber locations differed from each other in emission rates, the inter-annual dynamics were very similar and systematic. Accounting for this chamber location dependent variability, temperature and relative humidity, a mixed effects linear model was able to explain 79-88% of monoterpene, methanol, acetone, and acetaldehyde fluxes from the boreal forest floor. The boreal forest floor was a significant contributor in the forest stand fluxes, but its importance varies between seasons, being most important in autumn. The forest floor emitted 2-93% of monoterpene fluxes in spring and autumn and 1-72% of methanol fluxes in spring and early summer. The forest floor covered only a few percent of the forest stand fluxes in summer.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6395408 | PMC |
http://dx.doi.org/10.3389/fpls.2019.00191 | DOI Listing |
J Hazard Mater
January 2025
State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Elevated methylmercury (MeHg) exposure poses significant risks to bird health, behavior, and reproduction. Still, the risk of MeHg exposure to forest birds, accounting for over 80 % of the world's bird species, is poorly understood. This study combines Hg isotopes and video analysis, aiming to assess MeHg exposure risks to a forest riverine songbird, the spotted forktail (Enicurus maculatus) from a remote subtropical montane forest.
View Article and Find Full Text PDFDigit Health
January 2025
Department of Obstetrics and Gynecology, Seoul National University College of Medicine, Jongno-gu, Seoul, Korea.
Objective: Accurate measurement of pelvic floor muscle (PFM) strength is crucial for the management of pelvic floor disorders. However, the current methods are invasive, uncomfortable, and lack standardization. This study aimed to introduce a novel noninvasive approach for precise PFM strength quantification by leveraging extracorporeal surface perineal pressure (ESPP) measurements and machine learning algorithms.
View Article and Find Full Text PDFSci Rep
January 2025
School of Marine Science and Technology, Northwestern Polytechnical University, Xi'an, 710072, People's Republic of China.
This study develops predictive models for Chinese female patients with VL utilizing machine learning techniques. The aim is to create an effective model that can assist in clinical diagnosis and treatment of vaginal relaxation, thereby enhancing women's pelvic floor health. In total, 1184 women with VL have been randomly selected and categorized into groups using the finger measurement method.
View Article and Find Full Text PDFPLoS One
January 2025
Department of Computer Science, Virginia Tech, Arlington, VA, United States of America.
Trade in wood and forest products spans the global supply chain. Illegal logging and associated trade in forest products present a persistent threat to vulnerable ecosystems and communities. Illegal timber trade has been linked to violations of tax and conservation laws, as well as broader transnational crimes.
View Article and Find Full Text PDFFungal Syst Evol
December 2024
Programa de Pós-graduação em Botânica - DIPO 2, Instituto Nacional de Pesquisas da Amazônia - Inpa, Av. André Araújo 2936, 69067-375, Manaus, AM, Brazil.
Rhizomorphs are hair- or wire-like melanized structures with structural differentiation analogous to plant roots that help fungi spread over an area and find food resources. Some species of multiple groups of the and the produce different types of rhizomorphs. In the , the structures are largely found in , particularly in the , , and .
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!