The exchange of carbon dioxide is a key measure of ecosystem metabolism and a critical intersection
between the terrestrial biosphere and the Earth’s climate. Despite the general agreement that
the terrestrial ecosystems in North America provide a sizeable carbon sink, the size and distribution
of the sink remain uncertain. We...
Full Text:
aged pine 44.45 -121.56 ENF Law et al., 2003
US-Me3 Metolius-second young aged pine 44.32 -121.61 ENF
The exchange of carbon dioxide is a key measure of ecosystem metabolism and a critical intersection
between the terrestrial biosphere and the Earth’s climate. Despite the general agreement that
the terrestrial ecosystems in North America provide a sizeable carbon sink, the size and distribution
of the sink remain uncertain. We...
Full Text:
. Baldocchi i, BeveryE. Lawj, M. Altaf Araink, Ankur R. Desai l,
ndrew D. Richardsonm, Ge Sunn
The exchange of carbon dioxide is a key measure of ecosystem metabolism and a critical intersection
between the terrestrial biosphere and the Earth’s climate. Despite the general agreement that
the terrestrial ecosystems in North America provide a sizeable carbon sink, the size and distribution
of the sink remain uncertain. We...
Remote sensing of variables necessary to estimate net primary
production of vegetation over large temporal and spatial scales has been a
goal of climate change research. This thesis consists of two studies that
address the reliability of satellite and airborne sensors to quantify a basic
component of all production models,...
Severe droughts occurred in the western United States during recent decades, and continued human greenhouse gas emissions are expected to exacerbate warming and drying in this region. We investigated the role of water availability in shaping forest carbon cycling and morphological traits in the eastern Cascade Mountains, Oregon, focusing on...
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steep
climatic gradient in the Cascade Mountains, Oregon
L. T. Berner and B. E. Law
Correspondence
Severe droughts occurred in the western United States during recent decades, and continued human greenhouse gas emissions are expected to exacerbate warming and drying in this region. We investigated the role of water availability in shaping forest carbon cycling and morphological traits in the eastern Cascade Mountains, Oregon, focusing on...
Full Text:
, Oregon
Berner, L. T., & Law, B. E. (2015). Water limitations on forest carbon cycling and
conifer
Severe droughts occurred in the western United States during recent decades, and continued human greenhouse gas emissions are expected to exacerbate warming and drying in this region. We investigated the role of water availability in shaping forest carbon cycling and morphological traits in the eastern Cascade Mountains, Oregon, focusing on...
Severe droughts occurred in the western United States during recent decades, and continued human greenhouse gas emissions are expected to exacerbate warming and drying in this region. We investigated the role of water availability in shaping forest carbon cycling and morphological traits in the eastern Cascade Mountains, Oregon, focusing on...
Full Text:
, Oregon
Berner, L. T., & Law, B. E. (2015). Water limitations on forest carbon cycling and
conifer
Severe droughts occurred in the western United States during recent decades, and continued human greenhouse gas emissions are expected to exacerbate warming and drying in this region. We investigated the role of water availability in shaping forest carbon cycling and morphological traits in the eastern Cascade Mountains, Oregon, focusing on...
Severe droughts occurred in the western United States during recent decades, and continued human greenhouse gas emissions are expected to exacerbate warming and drying in this region. We investigated the role of water availability in shaping forest carbon cycling and morphological traits in the eastern Cascade Mountains, Oregon, focusing on...
Ecosystem process models are important tools for determining the interactive effects of global change and disturbance on forest carbon dynamics. Here we evaluated and improved terrestrial carbon cycling simulated by the Community Land Model (CLM4), the land model portion of the Community Earth System Model (CESM1.0.4). Our analysis was conducted...
Predicting the net effects on the carbon and water
balance of semi-arid forests under future conditions depends
on ecosystem processes responding to changes in
soil and atmospheric drought. Here we apply a combination
of field observations and soil–plant–atmosphere modeling
(SPA) to study carbon and water dynamics in a regenerating
ponderosa...
Predicting the net effects on the carbon and water
balance of semi-arid forests under future conditions depends
on ecosystem processes responding to changes in
soil and atmospheric drought. Here we apply a combination
of field observations and soil–plant–atmosphere modeling
(SPA) to study carbon and water dynamics in a regenerating
ponderosa...
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experimental and
modeling approach
Ruehr, N. K., Law, B. E., Quandt, D., & Williams, M. (2014). Effects of
Predicting the net effects on the carbon and water
balance of semi-arid forests under future conditions depends
on ecosystem processes responding to changes in
soil and atmospheric drought. Here we apply a combination
of field observations and soil–plant–atmosphere modeling
(SPA) to study carbon and water dynamics in a regenerating
ponderosa...
Background: Management strategies have been proposed to minimise the effects of climate
change on forest resilience.
Aims: We investigated the Pacific Northwest US region forest carbon balance under current
practices, and changes that may result from management practices proposed for the region’s
34 million ha of forests to mitigate climate...
Terrestrial ecosystem-atmosphere exchange of carbon, water vapor, and energy has been measured for over a decade at many sites globally. To minimize measurement and analysis errors, quality assurance data have been collected over short periods along-side tower instruments at AmeriFlux research sites. Theoretical and empirical error and uncertainty values have...
Two distinct nocturnal subcanopy flow regimes are observed beneath a tall (16 m) open pine forest canopy. The first is characterized by weaker mixing, stronger stability, westerly downslope flow decoupled from the flow above the canopy and much smaller than expected ecosystem respiration from the eddy flux plus storage measurements...
We sought to improve net ecosystem exchange (NEE) estimates for a tall, dense, mature Douglas-Fir forest in the Oregon Coast range characterized by weak flows, systematic wind directional shear, and limited turbulent mixing throughout the diurnal period. We used eddy covariance (EC) observations at two levels and concurrent biological measurements...
We present an atmospheric inverse modeling framework to constrain terrestrial biosphere CO₂ exchange processes at subregional scales. The model is operated at very high spatial and temporal resolution, using the state of Oregon in the northwestern United States as the model domain. The modeling framework includes mesoscale atmospheric simulations coupled...
This paper examines albedo perturbation and radiative forcing after a high-severity fire in a
mature forest in the Oregon Cascade Range. Correlations between postfire albedo and seedling, sapling,
and snag (standing dead tree) density were investigated across fire severity classes and seasons for years
4-15 after fire. Albedo perturbation was...
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. Joerger1, Jane Kertis3, Beverly E. Law4
1 – Sweet Briar College, Department of Environmental Science
This paper examines albedo perturbation and radiative forcing after a high-severity fire in a
mature forest in the Oregon Cascade Range. Correlations between postfire albedo and seedling, sapling,
and snag (standing dead tree) density were investigated across fire severity classes and seasons for years
4-15 after fire. Albedo perturbation was...
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., Acker, S. A., Joerger, V. M., Kertis, J., & Law, B. E. (2014).
Postfire influences of snag attrition on
A semi-parametric PAR diffuse radiation model
was developed using commonly measured climatic variables
from 108 site-years of data from 17 AmeriFlux sites. The
model has a logistic form and improves upon previous efforts
using a larger data set and physically viable climate
variables as predictors, including relative humidity, clearness
index,...
A semi-parametric PAR diffuse radiation model
was developed using commonly measured climatic variables
from 108 site-years of data from 17 AmeriFlux sites. The
model has a logistic form and improves upon previous efforts
using a larger data set and physically viable climate
variables as predictors, including relative humidity, clearness
index,...
Full Text:
Kathilankal, J. C., O'Halloran, T. L., Schmidt, A., Hanson, C. V., & Law, B. E.
(2014). Development of a semi
This study quantifies the short-term effects of low-, moderate-, and high-severity fire on carbon pools and fluxes in the Eastern Cascades of Oregon. We surveyed 64 forest stands across four fires that burned 41,000 ha (35%) of the Metolius Watershed in 2002 and 2003, stratifying the landscape by burn severity...
This paper examines albedo perturbation and radiative forcing after a high-severity fire in a
mature forest in the Oregon Cascade Range. Correlations between postfire albedo and seedling, sapling,
and snag (standing dead tree) density were investigated across fire severity classes and seasons for years
4-15 after fire. Albedo perturbation was...
In recent years, measurements of atmospheric carbon dioxide with high precision and accuracy have become increasingly important for climate change research, in particular to inform terrestrial biosphere models. Anthropogenic carbon dioxide emissions from fossil fuel burning have long been recognized to contribute a significant portion of the carbon dioxide in...
A semi-parametric PAR diffuse radiation model
was developed using commonly measured climatic variables
from 108 site-years of data from 17 AmeriFlux sites. The
model has a logistic form and improves upon previous efforts
using a larger data set and physically viable climate
variables as predictors, including relative humidity, clearness
index,...
Five years of eddy-covariance and other measurements at a mature ponderosa pine forest and a nearby young plantation are used to contrast the carbon fluxes for long-term averages, seasonal patterns, diel patterns and interannual variability, and to examine the differing responses to water-stress. The mature forest with larger leaf area...
We present an inverse modeling framework designed to constrain CO2 budgets at regional scales. The approach captures atmospheric transport processes in high spatiotemporal resolution by coupling a mesoscale model with Lagrangian Stochastic backward trajectories. Terrestrial biosphere CO₂ emissions are generated through a simple diagnostic flux model that splits the net...
Whole ecosystem carbon dioxide (CO₂) exchange estimated with the eddy covariance (EC) technique has been central to studies on the responses of terrestrial ecosystems to disturbance and intra‐annual and interannual variations in climate, but challenges exist in understanding and reducing the uncertainty in estimates of net ecosystem exchange (NEE) of...
We analyzed 7 years (2002–2008) of micrometeorological and concurrent biological
observations of carbon and water fluxes at a mature ponderosa pine forest in central
Oregon in a semiarid climate. We sought to evaluate the extent that gross primary
productivity, net ecosystem exchange, ecosystem respiration, net primary productivity, net
ecosystem productivity,...
Carbon sequestration is increasingly recognized as an ecosystem service, and forest management has a large potential to alter regional carbon fluxes − notably by way of harvest removals and related impacts on net ecosystem production (NEP). In the Pacific Northwest region of the U.S.,
the implementation of the Northwest Forest...
We propose the Breathing Earth System Simulator (BESS), an upscaling approach to quantify global gross primary productivity and evapotranspiration using MODIS with a spatial resolution of 1-5 km and a temporal resolution of 8 days. This effort is novel because it is the first system that harmonizes and utilizes MODIS...
Disturbance processes of various types substantially modify ecosystem carbon dynamics both temporally and spatially, and constitute a fundamental part of larger landscape-level dynamics. Forests typically lose carbon for several years to several decades following severe disturbance, but our understanding of the duration and dynamics of post-disturbance forest carbon fluxes remains...
Accurate and reliable estimates of gross primary productivity (GPP) are required for monitoring the global carbon cycle at different spatial and temporal scales. Because GPP displays high spatial and temporal variation, remote sensing plays a major role in producing gridded estimates of GPP across spatiotemporal scales. In this context, understanding...
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Accurate and reliable estimates of gross primary productivity (GPP) are required for monitoring the global carbon cycle at different spatial and temporal scales. Because GPP displays high spatial and temporal variation, remote sensing plays a major role in producing gridded estimates of GPP across spatiotemporal scales. In this context, understanding...
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The global terrestrial carbon sink offsets one-third of the world’s fossil fuel emissions, but the strength of this sink is highly sensitive to large-scale extreme events. In 2012, the contiguous United States experienced exceptionally warm temperatures and the most severe drought since the Dust Bowl era of the 1930s, resulting...
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The global terrestrial carbon sink offsets one-third of the world’s fossil fuel emissions, but the strength of this sink is highly sensitive to large-scale extreme events. In 2012, the contiguous United States experienced exceptionally warm temperatures and the most severe drought since the Dust Bowl era of the 1930s, resulting...
Full Text:
, Russell L. Scottg, Beverly E. Lawh, Marcy E. Litvaki, Nathaniel A. Brunsellj,
Wouter Petersk,l, and Ingrid
The global terrestrial carbon sink offsets one-third of the world’s fossil fuel emissions, but the strength of this sink is highly sensitive to large-scale extreme events. In 2012, the contiguous United States experienced exceptionally warm temperatures and the most severe drought since the Dust Bowl era of the 1930s, resulting...
Accurate and reliable estimates of gross primary productivity (GPP) are required for monitoring the global carbon cycle at different spatial and temporal scales. Because GPP displays high spatial and temporal variation, remote sensing plays a major role in producing gridded estimates of GPP across spatiotemporal scales. In this context, understanding...
Fossil fuel emissions aside, temperate North America is a net sink of carbon dioxide at present¹⁻³. Year-to-year variations in this carbon sink are linked to variations in hydroclimate that affect net ecosystem productivity³,⁴. The severity and incidence of climatic extremes, including drought, have increased as a result of climate warming⁵⁻⁸....
Surface albedo is a key parameter in the Earth's energy balance since it affects the amount of solar radiation directly absorbed at the planet surface. Its variability in time and space can be globally retrieved through the use of remote sensing products. To evaluate and improve the quality of satellite...
To guide the future development of CO₂-atmospheric inversion modeling systems, we analyzed the errors arising from prior information about terrestrial ecosystem fluxes. We compared the surface fluxes calculated by a process-based terrestrial ecosystem model with daily averages of CO₂ flux measurements at 156 sites across the world in the FLUXNET...
Gross primary productivity (GPP) is the largest
and most variable component of the global terrestrial carbon
cycle. Repeatable and accurate monitoring of terrestrial
GPP is therefore critical for quantifying dynamics in
regional-to-global carbon budgets. Remote sensing provides high frequency observations of terrestrial ecosystems and is
widely used to monitor and...
Full Text:
. Verma, M. A. Friedl, A. D. Richardson, G. Kiely, A. Cescatti, B. E. Law, G. Wohlfahrt, B.
Gielen, O
Gross primary productivity (GPP) is the largest
and most variable component of the global terrestrial carbon
cycle. Repeatable and accurate monitoring of terrestrial
GPP is therefore critical for quantifying dynamics in
regional-to-global carbon budgets. Remote sensing provides high frequency observations of terrestrial ecosystems and is
widely used to monitor and...
Full Text:
, M., Friedl, M. A., Richardson, A. D., Kiely, G., Cescatti, A., Law, B. E.,
Wohlfahrt, G., Gielen, B
Gross primary productivity (GPP) is the largest
and most variable component of the global terrestrial carbon
cycle. Repeatable and accurate monitoring of terrestrial
GPP is therefore critical for quantifying dynamics in
regional-to-global carbon budgets. Remote sensing provides high frequency observations of terrestrial ecosystems and is
widely used to monitor and...
Worldwide measurements of nearly 130C3 species covering all
major plant functional types are analysed in conjunction with
model simulations to determine the effects of mesophyll
conductance (gm) on photosynthetic parameters and their
relationships estimated from A/Ci curves. We find that an
assumption of infinite gm results in up to 75%...
Worldwide measurements of nearly 130C3 species covering all
major plant functional types are analysed in conjunction with
model simulations to determine the effects of mesophyll
conductance (gm) on photosynthetic parameters and their
relationships estimated from A/Ci curves. We find that an
assumption of infinite gm results in up to 75%...
Worldwide measurements of nearly 130C3 species covering all major plant functional types are analysed in conjunction with model simulations to determine the effects of mesophyll conductance (gm) on photosynthetic parameters and their relationships estimated from A/Ci curves. We find that an assumption of infinite gm results in up to 75%...