Science Current Events | Science News | Brightsurf.com
 

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

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,...

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 Combustion Science, Technology and Engineering (Woodhead Publishing Series in Energy)

Biomass Combustion Science, Technology and Engineering (Woodhead Publishing Series in Energy)
by Lasse Rosendahl (Editor)


The utilisation of biomass is increasingly important for low- or zero-carbon power generation. Developments in conventional power plant fuel flexibility allow for both direct biomass combustion and co-firing with fossil fuels, while the integration of advanced technologies facilitates conversion of a wide range of biomass feedstocks into more readily combustible fuel. Biomass combustion science, technology and engineering reviews the science and technology of biomass combustion, conversion and utilisation.

Part one provides an introduction to biomass supply chains and feedstocks, and outlines the principles of biomass combustion for power generation. Chapters also describe the categorisation and preparation of biomass feedstocks for combustion and gasification. Part two goes on to...

Biomass combustion science, technology and engineering: 5. Biomass co-firing (Woodhead Publishing Series in Energy)

Biomass combustion science, technology and engineering: 5. Biomass co-firing (Woodhead Publishing Series in Energy)
by Woodhead Publishing


Co-firing biomass with fossil fuels in existing power plants is an attractive option for significantly increasing renewable energy resource utilization and reducing CO2 emissions. This chapter mainly discusses three direct co-firing technologies: pulverized-fuel (PF) boilers, fluidized-bed combustion (FBC) systems, and grate-firing systems, which are employed in about 50%, 40%, and 10% of all the co-firing plants, respectively. Their basic principles, process technologies, advantages, and limitations are presented, followed by a brief comparison of these technologies when applied to biomass co-firing. This chapter also briefly introduces indirect co-firing and parallel co-firing and their application status.

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.

The Pros and Cons of Biomass Power (Energy Debate)

The Pros and Cons of Biomass Power (Energy Debate)
by Isabel Thomas (Author)


Explains and explores the use of biomass fuel.

Introduction to Biomass Energy Conversions

Introduction to Biomass Energy Conversions
by Sergio Capareda (Author)


The potential that biomass energy has to supplement traditional fuels and reduce greenhouse gas emissions has put it front and center in the plan to replace fossil-based fuels with renewable fuels. While much has been written about biomass conversions, no single textbook contains all the information needed to teach a biomass conversion course―until now. Introduction to Biomass Energy Conversions presents a comprehensive review of biomass resources available for conversion into heat, power, and biofuels. The textbook covers biomass characterization and discusses facilities, equipment, and standards (e.g. ASTM or NREL) used for analysis. It examines the range of biomass resources available for conversion and presents traditional biomass conversion processes along with extensive biomass...

Pyrolysis of Biomass (Green  Alternative Energy Resources)

Pyrolysis of Biomass (Green Alternative Energy Resources)
by Shurong Wang (Author), Zhongyang Luo (Author), China Science Publishing & Media Ltd (Contributor)


With the development of societies fossil energy is no longer the only energy resource, and increasing attention had been paid to alternative energy. Biomass is considered to be one of the alternatives due to efficiency and low cost. This book presents biomass pyrolysis behavior for three main components: Cellulose, Hemicellulose and Lignin, and discusses the influence of mineral salts, zeolite catalysts and metal oxide on their pyrolysis. "

Perennial Biomass Crops for a Resource-Constrained World

Perennial Biomass Crops for a Resource-Constrained World
by Susanne Barth (Editor), Donal Murphy-Bokern (Editor), Olena Kalinina (Editor), Gail Taylor (Editor), Michael Jones (Editor)


This book presents a flavour of activities focussed on the need for sustainably produced biomass to support European strategic objectives for the developing bioeconomy. The chapters cover five broad topic areas relating to the use of perennial biomass crops in Europe. These are: ‘Bioenergy Resources from Perennial Crops in Europe’, ‘European Regional Examples for the Use of Perennial Crops for Bioenergy’, ‘Genotypic Selection of Perennial Biomass Crops for Crop Improvement’, ‘Ecophysiology of Perennial Biomass Crops’ and ‘Examples of End-Use of Perennial Biomass Crops’. Two major issues relating to the future use of biomass energy are the identification of the most suitable second generation biomass crops and the need to utilise land not under intensive agricultural...

  Biomass Assessment (Energy and Infrastructure Set)
by Andrew Millington (Author), John Townsend (Author)


Energy is an issue for everyone and nowhere more so than in the SADCC countries. But for sensible policy and planning, clear information about the extent of resources is needed. This innovative study combines the results of field assessment of biomass with advanced techniques in remote sensing by satellite to give the first comprehensive and detailed picture of biomass distribution throughout the SADCC region. The authors describe their techniques, classify the kinds of biomass and give its distribution, by that classification, in all nine SADCC countries. Woody biomass resources and supplies are clearly analysed. This book is essential reading for project officers, planners and all others involved in the collection and analysis of data on biomass resources throughout the world. ...

© 2016 BrightSurf.com