Science Current Events | Science News |

Handful of heavyweight trees per acre are forest champs

May 03, 2012

Big trees three or more feet in diameter accounted for nearly half the biomass measured at a Yosemite National Park site, yet represented only one percent of the trees growing there.

This means just a few towering white fir, sugar pine and incense cedars per acre at the Yosemite site are disproportionately responsible for photosynthesis, converting carbon dioxide into plant tissue and sequestering that carbon in the forest, sometimes for centuries, according to James Lutz, a University of Washington research scientist in environmental and forest sciences. He's lead author of a paper on the largest quantitative study yet of the importance of big trees in temperate forests being published online May 2 on PLoS ONE.

"In a forest comprised of younger trees that are generally the same age, if you lose one percent of the trees, you lose one percent of the biomass," he said. "In a forest with large trees like the one we studied, if you lose one percent of the trees, you could lose half the biomass."

In 2009, scientists including Lutz reported that the density of large-diameter trees declined nearly 25 percent between the 1930s and 1990s in Yosemite National Park, even though the area was never logged. Scientists including co-author Andrew Larson of the University of Montana, also have found notable numbers of large trees dying in similar areas across the West.

Because of this, scientists have been keen to study a plot large enough to detect forest ecosystem changes involving large trees, including the effects of climate variability and change, possible culprits in the declines, Lutz said.

The new 63-acre study site in the western part of Yosemite National Park is one of the largest, fully-mapped plots in the world and the largest old-growth plot in North America. The tally of what's there, including the counting and tagging of 34,500 live trees, was done by citizen scientists, mainly undergraduate college students, led by Lutz, Larson, Mark Swanson of Washington State University and James Freund of the UW.

Included was all above-ground biomass such as live trees, snags, downed woody debris, litter and what's called duff, the decaying plant matter on the ground under trees. Even when big trees die, they continue to dominate biomass in different ways. For example, 12 percent of standing snags were the remains of large-diameter trees, but still accounted for 60 percent of the total biomass of snags.

Live and dead biomass totaled 280 tons per acre (652 metric tons per hectare), a figure unmatched by any other forest in the Smithsonian Center for Tropical Forest Science network, a global network of 42 tropical and temperate forest plots including the one in Yosemite.

Trees in the western U.S. with trunks more than three feet across are typically at least 200 years old. Many forests that were heavily harvested in the 19th and 20th centuries, or those that are used as commercial forest lands today, don't generally have large-diameter trees, snags or large wood on the ground.

One implication of the research is that land managers may want to pay more attention to existing big trees, the co-authors said. Last year in the Yosemite National Park, for example, managers planning to set fires to clear out overgrown brush and densely packed small trees first used data from the study plot to figure out how many large trees to protect.

"Before the fires were started, crews raked around some of the large trees so debris wouldn't just sit and burn at the base of the tree and kill the cambium, the tissue under the bark that sustains trees," Lutz said.

In some younger forests that lack big trees, citizens and land managers might want to consider fostering the growth of a few big-trunked trees, Lutz said.

Another finding from the new work is that forest models based either on scaling theory or competition theory, which are useful for younger, more uniform forests, fail to capture how and where large trees occur in forests.

"These trees started growing in the Little Ice Age," Lutz said. "Current models can't fully capture the hundreds of years of dynamic processes that have shaped them during their lifetimes."

University of Washington

Related Biomass Current Events and Biomass News Articles

Hydrothermal vents, methane seeps play enormous role in marine life, global climate
The hydrothermal vents and methane seeps on the ocean floor that were once thought to be geologic and biological oddities are now emerging as a major force in ocean ecosystems, marine life and global climate.

UM researcher embarks on field campaign to study effects of smoke on Earth's climate
A scientist at the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science is leading an upcoming international research campaign to study a significant contributor to regional climate warming - smoke.

PNNL helps lead national microbiome initiative
Scientists at the U.S. Department of Energy's Pacific Northwest National Laboratory are playing a central role as the nation devotes more than $500 million to understand communities of microorganisms and their role in climate science, food production and human health.

Women cooking with biomass fuels more likely to have cataracts
Women in India who cook using fuels such as wood, crop residues and dried dung instead of cleaner fuels are more likely to have visually impairing nuclear cataracts, according to a new study published in the journal Environmental Health Perspectives.

Current atmospheric models underestimate the dirtiness of Arctic air
Black carbon aerosols--particles of carbon that rise into the atmosphere when biomass, agricultural waste, and fossil fuels are burned in an incomplete way--are important for understanding climate change, as they absorb sunlight, leading to higher atmospheric temperatures, and can also coat Arctic snow with a darker layer, reducing its reflectivity and leading to increased melting.

Global data shows inverse relationship, shift in human use of fire
Humans use fire for heating, cooking, managing lands and, more recently, fueling industrial processes. Now, research from the University of Colorado has found that these various means of using fire are inversely related to one another, providing new insight into how people are changing the face of fire.

UMMS scientists create computational tool for greater understanding of metabolic network
Scientists at UMass Medical School have created a computational network model that will enable the unraveling of the mechanisms by which different macro- and micronutrients contribute to the physiology of the nematode C. elegans, which is a primary model for understanding human physiology and disease.

Natural regeneration of tropical forests helps global climate mitigation and forest restoration
Climate scientists have long recognized the importance of forest conservation and forest regrowth in climate mitigation and carbon sequestration -- capturing carbon dioxide (CO2) from the atmosphere.

Biodiversity protects fish from climate change
Fish provide protein to billions of people and are an especially critical food source in the developing world.

Natural regeneration of tropical forests reaps benefits
The importance of forest conservation and forest regrowth in climate mitigation and carbon sequestration - capturing carbon dioxide (CO2) from the atmosphere - has long been recognized by climate scientists. But, detailed information needed to make accurate estimates of this potential has been missing.
More Biomass Current Events and Biomass News Articles

The Biomass Revolution (Volume 1)

The Biomass Revolution (Volume 1)
by Nicholas Sansbury Smith (Author)

What would you do if you lived in a world where your every move was scrutinized by your own personal artificial intelligence--a world where everything is regulated, from power usage to relationships--a world where everything you thought you knew turned out to be a lie?  Welcome to Tisaia - The last hub of modern civilization in a world left scorched by the nuclear fires of the Biomass Wars. Surrounded by a fortress of steel walls and protected by a fierce and loyal Council of Royal Knights, Tisaia seems relatively safe to the average State worker and citizen. A plentiful supply of Biomass powers the cities and food is abundant, but security has come at a terrible cost. The State will do anything to protect its resources, even if it means suppressing the rights of its citizens and...

Biomass to Renewable Energy Processes, Second Edition

Biomass to Renewable Energy Processes, Second Edition
by Jay Cheng (Editor)

Biomass to Renewable Energy Processes, Second Edition, explains the theories of biological processes, biomass materials and logistics, and conversion technologies for bioenergy products such as biogas, ethanol, butanol, biodiesel, and synthetic gases. The book discusses anaerobic digestion of waste materials for biogas and hydrogen production, bioethanol and biobutanol production from starch and cellulose, and biodiesel production from plant oils. It addresses thermal processes, including gasification and pyrolysis of agricultural residues and woody biomass. The text also covers pretreatment technologies, enzymatic reactions, fermentation, and microbiological metabolisms and pathways.

Biomass to Renewable Energy Processes

Biomass to Renewable Energy Processes
by Jay Cheng (Editor)

Continuously increased consumption of fossil fuels, decreased availability of easily accessible fossil fuels, significant contributions to climate change and wildly fluctuating fuels prices have combine to challenge the reliability and sustainability of our current energy supply. A possible solution to this energy challenge, biomass energy production, heavily dependent on sugarcane and corn production, is vulnerable to the fluctuation of the feedstock price. New technologies need to be developed to convert abundant biomass such as lignocellulosic materials into energy products in a cost-effective and environmentally friendly manner. An introduction to fundamental principles and practical applications, Biomass to Renewable Energy Processes explains the theories of biological processes,...

Biomass and Bioenergy: Processing and Properties

Biomass and Bioenergy: Processing and Properties
by Khalid Rehman Hakeem (Editor), Mohammad Jawaid (Editor), Umer Rashid (Editor)

Biomass obtained from agricultural residues or forest can be used to produce different materials and bioenergy required in a modern society. As compared to other resources available, biomass is one of the most common and widespread resources in the world. Thus, biomass has the potential to provide a renewable energy source, both locally and across large areas of the world. It is estimated that the total investment in the biomass sector between 2008 and 2021 will reach the large sum of $104 billion. Presently bioenergy is the most important renewable energy option and will remain so the near and medium-term future. Previously several countries try to explore the utilization of biomass in bioenergy and composite sector. Biomass has the potential to become the world’s largest and most...

Biomass: Fueling Change (Energy Revolution)

Biomass: Fueling Change (Energy Revolution)
by Niki Walker (Author)

This book is suitable for readers of ages 9-12. This is an exciting new book that explores bioenergy, which is energy derived from organic matter, to produce heat, run cars, and generate electricity.

2011 Biomass Energy and Biofuels Encyclopedia - Comprehensive Coverage of All Aspects of Alternative Fuels, Biodiesel, Ethanol, Methanol, Markets and Technology (DVD-ROM)

2011 Biomass Energy and Biofuels Encyclopedia - Comprehensive Coverage of All Aspects of Alternative Fuels, Biodiesel, Ethanol, Methanol, Markets and Technology (DVD-ROM)
by U.S. Government (Author), Department of Energy (DOE) (Author), National Renewable Energy Laboratory (NREL) (Author)

This electronic book on DVD-ROM provides an unprecedented encyclopedic collection of authoritative official documents, reference books, guides, handbooks, and technical reports about every conceivable aspect of biomass energy and biofuels, including alternative fuels like biodiesel, ethanol, methanol - with over 70,000 pages of invaluable material presented in Adobe Acrobat PDF format. This incredible library has been revised and updated for this 2011 edition. Progressive Management has been a leader in renewable energy publishing for nearly a decade, and we believe that this exceptional collection provides the most comprehensive set of government biomass and biofuel documents ever offered! If you have a professional or personal interest in biomass, you will find this disc to be an...

Biomass and Alternate Fuel Systems: An Engineering and Economic Guide

Biomass and Alternate Fuel Systems: An Engineering and Economic Guide
by Thomas F. McGowan (Editor), Michael L. Brown (Editor), William S. Bulpitt (Editor), James L. Walsh Jr. (Editor)

This book explains characteristics of renewable fuels, especially biomass and wood, and the cost-effective and environment-friendly methods of handling, storing and burning these fuels. It is complete with the economic evaluation method, introduction of the pollution control equipment for limiting the emission from fuel combustion, case studies, and costs and carbon emission comparisons between conventional and alternate fuels. Many case studies are introduced here too.

This book is an update and expansion of the "Industrial Wood Energy Handbook" by a team from the Georgia Institute of Technology in 1984. It introduces new technologies new technologies not available at the time of the early version.

Sustainable Polymers from Biomass

Sustainable Polymers from Biomass
by Chuanbing Tang (Editor), Chang Y. Ryu (Editor)

Offering a unique perspective summarizing research on this timely important topic around the globe, this book provides comprehensive coverage of how molecular biomass can be transformed into sustainable polymers. It critically discusses and compares a few classes of biomass - oxygen-rich, hydrocarbon-rich, hydrocarbon and non-hydrocarbon (including carbon dioxide) as well as natural polymers - and equally includes products that are already commercialized.

A must-have for both newcomers to the field as well as established researchers in both academia and industry.

Hydrothermal Processing in Biorefineries: Production of Bioethanol and High Added-Value Compounds of Second and Third Generation Biomass

Hydrothermal Processing in Biorefineries: Production of Bioethanol and High Added-Value Compounds of Second and Third Generation Biomass
by Héctor A. Ruiz (Editor), Mette Hedegaard Thomsen (Editor), Heather L. Trajano (Editor)

The biorefinery, integration of processes and technologies for biomass conversion, demands efficient utilization of all components. Hydrothermal processing is a potential clean technology to convert raw materials such as lignocellulosic and aquatic biomass into bioenergy and high added-value compounds. This book aims to show fundamental concepts and key technological developments that enabled industrial application of hydrothermal processing.  The scope of this book is primarily for scientists working in the biorefinery field as well as engineers from industry and potential investors in biofuels. Therefore, the information in this book will provide an overview of this technology applied to lignocellulosic materials and aquatic biomass, and especially new knowledge. Critically, this book...

Handbook of Biomass Downdraft Gasifier Engine Systems

Handbook of Biomass Downdraft Gasifier Engine Systems
by Solar Technical Information Program (Author), Solar Energy Research Institute (Contributor), U.S. Department of Energy (Contributor)

This handbook explains how biomass can be converted to a gas in a downdraft gasifier and gives details for designing, testing, operating, and manufacturing gasifiers and gasifier systems, primarily for shaft power generation up to 200 kW. t is intended to help convert gasification from a practical art into a field of en­gineered design. Although the handbook focuses on downdraft gasification as the only method suitable for small-scale power systems, it also gives extensive detail on biomass fuels, gas testing and cleanup in­strumentation, and safety considerations that will be of use to all those who work with gasifiers at whatever scale. The combustion of biomass in wood stoves and in­dustrial boilers has increased dramatically in some areas, and forest, agricultural, and paper...

© 2017