Age structure and disturbance legacy of North American forests

Abstract. Most forests of the world are recovering from a past disturbance. It is well known that forest disturbances profoundly affect carbon stock and fluxes in forest ecosystems, yet it has been a great challenge to assess disturbance impacts in estimates of forest carbon budgets. Net sequestration or loss of CO2 by forests after disturbance follows a predictable pattern with forest recovery. Forest age, which is related to time since disturbance, is the most available surrogate variable for various forest carbon analyses that concern the impact of disturbance. In this study, we compiled the first continental forest age map of North America by combining forest inventory data, historical fire data, optical satellite data and the dataset from NASA's LEDAPS project. Mexico and interior Alaska are excluded from this initial map due to unavailability of all required data sets, but work is underway to develop some different methodology for these areas. We discuss the significance of disturbance legacy from the past, as represented by current forest age structure in different regions of the US and Canada, tracking back disturbances caused by human and nature over centuries and at various scales. We also show how such information can be used with inventory data for analyzing carbon management opportunities, and other modeling applications. By combining geographic information about forest age with estimated C dynamics by forest type, it is possible to conduct a simple but powerful analysis of the net CO2 uptake by forests, and the potential for increasing (or decreasing) this rate as a result of direct human intervention in the disturbance/age status. The forest age map may also help address the recent concern that the terrestrial C sink from forest regrowth in North America may saturate in the next few decades. Finally, we describe how the forest age data can be used in large-scale carbon modeling, both for land-based biogeochemistry models and atmosphere-based inversion models, in order to improve the spatial accuracy of carbon cycle simulations.

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Age structure and disturbance legacy of North American forests

Biogeosciences ◽

10.5194/bg-8-715-2011 ◽

2011 ◽

Vol 8 (3) ◽

pp. 715-732 ◽

Cited By ~ 174

Author(s):

Y. Pan ◽

J. M. Chen ◽

R. Birdsey ◽

K. McCullough ◽

L. He ◽

...

Keyword(s):

Age Structure ◽

Forest Type ◽

Processing System ◽

Forest Carbon ◽

Forest Recovery ◽

Co2 Uptake ◽

Forest Age ◽

Inventory Data ◽

Disturbance Legacy ◽

The Impact

Abstract. Most forests of the world are recovering from a past disturbance. It is well known that forest disturbances profoundly affect carbon stocks and fluxes in forest ecosystems, yet it has been a great challenge to assess disturbance impacts in estimates of forest carbon budgets. Net sequestration or loss of CO2 by forests after disturbance follows a predictable pattern with forest recovery. Forest age, which is related to time since disturbance, is a useful surrogate variable for analyses of the impact of disturbance on forest carbon. In this study, we compiled the first continental forest age map of North America by combining forest inventory data, historical fire data, optical satellite data and the dataset from NASA's Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS) project. A companion map of the standard deviations for age estimates was developed for quantifying uncertainty. We discuss the significance of the disturbance legacy from the past, as represented by current forest age structure in different regions of the US and Canada, by analyzing the causes of disturbances from land management and nature over centuries and at various scales. We also show how such information can be used with inventory data for analyzing carbon management opportunities. By combining geographic information about forest age with estimated C dynamics by forest type, it is possible to conduct a simple but powerful analysis of the net CO2 uptake by forests, and the potential for increasing (or decreasing) this rate as a result of direct human intervention in the disturbance/age status. Finally, we describe how the forest age data can be used in large-scale carbon modeling, both for land-based biogeochemistry models and atmosphere-based inversion models, in order to improve the spatial accuracy of carbon cycle simulations.

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A Global Synthesis Inversion Analysis of Recent Variability in CO<sub>2</sub> Fluxes Using GOSAT and In Situ Observations

10.5194/acp-2017-960 ◽

2017 ◽

Cited By ~ 1

Author(s):

James S. Wang ◽

S. Randolph Kawa ◽

G. James Collatz ◽

Motoki Sasakawa ◽

Luciana V. Gatti ◽

...

Keyword(s):

North America ◽

Heat Waves ◽

Value Added ◽

Co2 Uptake ◽

Fire Emissions ◽

Continental Scale ◽

Spatial Coverage ◽

The Tropics ◽

The Impact

Abstract. The precise contribution of the two major sinks for anthropogenic CO2 emissions, terrestrial vegetation and the ocean, and their location and year-to-year variability are not well understood. Top-down estimates of the spatiotemporal variations in emissions and uptake of CO2 are expected to benefit from the increasing measurement density brought by recent in situ and remote CO2 observations. We uniquely apply a batch Bayesian synthesis inversion at relatively high resolution to in situ surface observations and bias-corrected GOSAT satellite column CO2 retrievals to deduce the global distributions of natural CO2 fluxes during 2009–2010. Our objectives include evaluating bottom-up prior flux estimates, assessing the value added by the satellite data, and examining the impacts of inversion technique and assumptions on posterior fluxes and uncertainties. The GOSAT inversion is generally better constrained than the in situ inversion, with smaller posterior regional flux uncertainties and correlations, because of greater spatial coverage, except over North America and high-latitude ocean. Complementarity of the in situ and GOSAT data enhances uncertainty reductions in a joint inversion; however, spatial and temporal gaps in sampling still limit the ability to accurately resolve fluxes down to the sub-continental scale. The GOSAT inversion produces a shift in the global CO2 sink from the tropics to the north and south relative to the prior, and an increased source in the tropics of ~ 2 Pg C y−1 relative to the in situ inversion, similar to what is seen in studies using other inversion approaches. This result may be driven by sampling and residual retrieval biases in the GOSAT data, as suggested by significant discrepancies between posterior CO2 distributions and surface in situ and HIPPO mission aircraft data. While the shift in the global sink appears to be a robust feature of the inversions, the partitioning of the sink between land and ocean in the inversions using either in situ or GOSAT data is found to be sensitive to prior uncertainties because of negative correlations in the flux errors. The GOSAT inversion indicates significantly less CO2 uptake in summer of 2010 than in 2009 across northern regions, consistent with the impact of observed severe heat waves and drought. However, observations from an in situ network in Siberia imply that the GOSAT inversion exaggerates the 2010–2009 difference in uptake in that region, while the prior CASA-GFED model of net ecosystem production and fire emissions reasonably estimates that quantity. The prior, in situ posterior, and GOSAT posterior all indicate greater uptake over North America in spring to early summer of 2010 than in 2009, consistent with wetter conditions. The GOSAT inversion does not show the expected impact on fluxes of a 2010 drought in the Amazon; evaluation of posterior mole fractions against local aircraft profiles suggests that time-varying GOSAT coverage can bias estimation of flux interannual variability in this region.

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A global synthesis inversion analysis of recent variability in CO<sub>2</sub> fluxes using GOSAT and in situ observations

Atmospheric Chemistry and Physics ◽

10.5194/acp-18-11097-2018 ◽

2018 ◽

Vol 18 (15) ◽

pp. 11097-11124 ◽

Cited By ~ 13

Author(s):

James S. Wang ◽

S. Randolph Kawa ◽

G. James Collatz ◽

Motoki Sasakawa ◽

Luciana V. Gatti ◽

...

Keyword(s):

North America ◽

Heat Waves ◽

Joint Inversion ◽

Co2 Uptake ◽

Fire Emissions ◽

Spatial Coverage ◽

Basin Scale ◽

The Tropics ◽

The Impact

Abstract. The precise contribution of the two major sinks for anthropogenic CO2 emissions, terrestrial vegetation and the ocean, and their location and year-to-year variability are not well understood. Top-down estimates of the spatiotemporal variations in emissions and uptake of CO2 are expected to benefit from the increasing measurement density brought by recent in situ and remote CO2 observations. We uniquely apply a batch Bayesian synthesis inversion at relatively high resolution to in situ surface observations and bias-corrected GOSAT satellite column CO2 retrievals to deduce the global distributions of natural CO2 fluxes during 2009–2010. The GOSAT inversion is generally better constrained than the in situ inversion, with smaller posterior regional flux uncertainties and correlations, because of greater spatial coverage, except over North America and northern and southern high-latitude oceans. Complementarity of the in situ and GOSAT data enhances uncertainty reductions in a joint inversion; however, remaining coverage gaps, including those associated with spatial and temporal sampling biases in the passive satellite measurements, still limit the ability to accurately resolve fluxes down to the sub-continental or sub-ocean basin scale. The GOSAT inversion produces a shift in the global CO2 sink from the tropics to the north and south relative to the prior, and an increased source in the tropics of ∼ 2 Pg C yr−1 relative to the in situ inversion, similar to what is seen in studies using other inversion approaches. This result may be driven by sampling and residual retrieval biases in the GOSAT data, as suggested by significant discrepancies between posterior CO2 distributions and surface in situ and HIPPO mission aircraft data. While the shift in the global sink appears to be a robust feature of the inversions, the partitioning of the sink between land and ocean in the inversions using either in situ or GOSAT data is found to be sensitive to prior uncertainties because of negative correlations in the flux errors. The GOSAT inversion indicates significantly less CO2 uptake in the summer of 2010 than in 2009 across northern regions, consistent with the impact of observed severe heat waves and drought. However, observations from an in situ network in Siberia imply that the GOSAT inversion exaggerates the 2010–2009 difference in uptake in that region, while the prior CASA-GFED model of net ecosystem production and fire emissions reasonably estimates that quantity. The prior, in situ posterior, and GOSAT posterior all indicate greater uptake over North America in spring to early summer of 2010 than in 2009, consistent with wetter conditions. The GOSAT inversion does not show the expected impact on fluxes of a 2010 drought in the Amazon; evaluation of posterior mole fractions against local aircraft profiles suggests that time-varying GOSAT coverage can bias the estimation of interannual flux variability in this region.

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Pentecostalism and African diaspora : a case study of the Redeemed Christian Church of God (RCCG), in North America

African Journal of Religion, Philosophy and Culture ◽

10.31920/2634-7644/2020/1n2a5 ◽

2020 ◽

Vol 1 (2) ◽

pp. 77-92

Author(s):

Rotimi Williams Omotoye

Keyword(s):

United States ◽

North America ◽

United States Of America ◽

The United States ◽

Church Of God ◽

Sources Of Information ◽

Christian Church ◽

Secondary Sources ◽

The Impact ◽

The Church

Pentecostalism as a new wave of Christianity became more pronounced in 1970's and beyond in Nigeria. Since then scholars of Religion, History, Sociology and Political Science have shown keen interest in the study of the Churches known as Pentecostals because of the impact they have made on the society. The Redeemed Christian Church of God (RCCG) was established by Pastor Josiah Akindayomi in Lagos,Nigeria in 1952. After his demise, he was succeeded by Pastor Adeboye Adejare Enock. The problem of study of this research was an examination of the expansion of the Redeemed Christian Church of God to North America, Caribbean and Canada. The missionary activities of the church could be regarded as a reversed mission in the propagation of Christianity by Africans in the Diaspora. The methodology adopted was historical. The primary and secondary sources of information were also germane in the research. The findings of the research indicated that the Redeemed Christian Church of God was founded in North America by Immigrants from Nigeria. Pastor Adeboye Enock Adejare had much influence on the Church within and outside the country because of his charisma. The Church has become a place of refuge for many immigrants. They are also contributing to the economy of the United States of America. However, the members of the Church were faced with some challenges, such as security scrutiny by the security agencies. In conclusion, the RCCGNA was a denomination that had been accepted and embraced by Nigerians and African immigrants in the United States of America.

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Is there an imbalance in the supply and demand for universal accessibility knowledge? Twenty years of UAIS papers viewed through the lens of WCAG

Universal Access in the Information Society ◽

10.1007/s10209-021-00834-y ◽

2021 ◽

Author(s):

Frode Eika Sandnes

Keyword(s):

Latin America ◽

North America ◽

Supply And Demand ◽

Research Focus ◽

Universal Accessibility ◽

Geographical Regions ◽

Research Profile ◽

The Impact ◽

Over Time

AbstractPurpose: Some universal accessibility practitioners have voiced that they experience a mismatch in the research focus and the need for knowledge within specialized problem domains. This study thus set out to identify the balance of research into the main areas of accessibility, the impact of this research, and how the research profile varies over time and across geographical regions. Method: All UAIS papers indexed in Scopus were analysed using bibliometric methods. The WCAG taxonomy of accessibility was used for the analysis, namely perceivable, operable, and understandable. Results: The results confirm the expectation that research into visual impairment has received more attention than papers addressing operable and understandable. Although papers focussing on understandable made up the smallest group, papers in this group attracted more citations. Funded research attracted fewer citations than research without funding. The breakdown of research efforts appears consistent over time and across different geographical regions. Researchers in Europe and North America have been active throughout the last two decades, while Southeast Asia, Latin America, and Middle East became active in during the last five years. There is also seemingly a growing trend of out-of-scope papers. Conclusions: Based on the findings, several recommendations are proposed to the UAIS editorial board.

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Impact of Atmospheric Optical Properties on Net Ecosystem Productivity of Peatland in Poland

Remote Sensing ◽

10.3390/rs13112124 ◽

2021 ◽

Vol 13 (11) ◽

pp. 2124

Author(s):

Kamila M. Harenda ◽

Mateusz Samson ◽

Radosław Juszczak ◽

Krzysztof M. Markowicz ◽

Iwona S. Stachlewska ◽

...

Keyword(s):

Optical Properties ◽

Diffuse Radiation ◽

Co2 Uptake ◽

High Carbon ◽

Atmospheric Scattering ◽

Net Productivity ◽

Diffusion Index ◽

Ecosystem Production ◽

The Impact ◽

Global Carbon

Peatlands play an important role in the global carbon cycle due to the high carbon storage in the substrate. Ecosystem production depends, for example, on the solar energy amount that reaches the vegetation, however the diffuse component of this flux can substantially increase ecosystem net productivity. This phenomenon is observed in different ecosystems, but the study of the atmosphere optical properties on peatland production is lacking. In this paper, the presented methodology allowed us to disentangle the diffuse radiation impact on the net ecosystem production (NEP) of Rzecin peatland, Poland. It allowed us to assess the impact of the atmospheric scattering process determined by the aerosol presence in the air mass. An application of atmospheric radiation transfer (ART) and ecosystem production (EP) models showed that the increase of aerosol optical thickness from 0.09 to 0.17 caused NEP to rise by 3.4–5.7%. An increase of the diffusion index (DI) by 0.1 resulted in an NEP increase of 6.1–42.3%, while a DI decrease of 0.1 determined an NEP reduction of −49.0 to −10.5%. These results show that low peatland vegetation responds to changes in light scattering. This phenomenon should be taken into account when calculating the global CO2 uptake estimation of such ecosystems.

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Framing Forest Carbon for Policy in Temperate North America: Baby Steps toward National Carbon Goals

Forests ◽

10.3390/f12081033 ◽

2021 ◽

Vol 12 (8) ◽

pp. 1033

Author(s):

Lloyd C. Irland ◽

John Hagan

Keyword(s):

Forest Management ◽

North America ◽

North American ◽

American Options ◽

Forest Carbon ◽

Special Issue

Why have a special issue on North American options for reducing national CO2 footprints through forest management [...]

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Rapid Assessment of Tree Damage Resulting from a 2020 Windstorm in Iowa, USA

Forests ◽

10.3390/f12050555 ◽

2021 ◽

Vol 12 (5) ◽

pp. 555

Author(s):

Thomas C. Goff ◽

Mark D. Nelson ◽

Greg C. Liknes ◽

Tivon E. Feeley ◽

Scott A. Pugh ◽

...

Keyword(s):

Forest Inventory ◽

Damage Zone ◽

Satellite Image ◽

Rapid Assessment ◽

Aerial Survey ◽

Inventory Data ◽

Tree Damage ◽

Forest Inventory Data ◽

Damage Susceptibility ◽

The Impact

A need to quantify the impact of a particular wind disturbance on forest resources may require rapid yet reliable estimates of damage. We present an approach for combining pre-disturbance forest inventory data with post-disturbance aerial survey data to produce design-based estimates of affected forest area and number and volume of trees damaged or killed. The approach borrows strength from an indirect estimator to adjust estimates from a direct estimator when post-disturbance remeasurement data are unavailable. We demonstrate this approach with an example application from a recent windstorm, known as the 2020 Midwest Derecho, which struck Iowa, USA, and adjacent states on 10–11 August 2020, delivering catastrophic damage to structures, crops, and trees. We estimate that 2.67 million trees and 1.67 million m3 of sound bole volume were damaged or killed on 23 thousand ha of Iowa forest land affected by the 2020 derecho. Damage rates for volume were slightly higher than for number of trees, and damage on live trees due to stem breakage was more prevalent than branch breakage, both likely due to higher damage probability in the dominant canopy of larger trees. The absence of post-storm observations in the damage zone limited direct estimation of storm impacts. Further analysis of forest inventory data will improve understanding of tree damage susceptibility under varying levels of storm severity. We recommend approaches for improving estimates, including increasing spatial or temporal extents of reference data used for indirect estimation, and incorporating ancillary satellite image-based products.

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A Link between the Hiatus in Global Warming and North American Drought

Journal of Climate ◽

10.1175/jcli-d-14-00616.1 ◽

2015 ◽

Vol 28 (9) ◽

pp. 3834-3845 ◽

Cited By ~ 69

Author(s):

Thomas L. Delworth ◽

Fanrong Zeng ◽

Anthony Rosati ◽

Gabriel A. Vecchi ◽

Andrew T. Wittenberg

Keyword(s):

Global Warming ◽

North America ◽

Surface Temperature ◽

North American ◽

Radiative Forcing ◽

Tropical Pacific ◽

Global Warming Hiatus ◽

Warming Hiatus ◽

The Impact ◽

The Tropical Pacific

Abstract Portions of western North America have experienced prolonged drought over the last decade. This drought has occurred at the same time as the global warming hiatus—a decadal period with little increase in global mean surface temperature. Climate models and observational analyses are used to clarify the dual role of recent tropical Pacific changes in driving both the global warming hiatus and North American drought. When observed tropical Pacific wind stress anomalies are inserted into coupled models, the simulations produce persistent negative sea surface temperature anomalies in the eastern tropical Pacific, a hiatus in global warming, and drought over North America driven by SST-induced atmospheric circulation anomalies. In the simulations herein the tropical wind anomalies account for 92% of the simulated North American drought during the recent decade, with 8% from anthropogenic radiative forcing changes. This suggests that anthropogenic radiative forcing is not the dominant driver of the current drought, unless the wind changes themselves are driven by anthropogenic radiative forcing. The anomalous tropical winds could also originate from coupled interactions in the tropical Pacific or from forcing outside the tropical Pacific. The model experiments suggest that if the tropical winds were to return to climatological conditions, then the recent tendency toward North American drought would diminish. Alternatively, if the anomalous tropical winds were to persist, then the impact on North American drought would continue; however, the impact of the enhanced Pacific easterlies on global temperature diminishes after a decade or two due to a surface reemergence of warmer water that was initially subducted into the ocean interior.

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Evaluating the Potential of Commercial Forest Inventory Data to Report on Forest Carbon Stock and Forest Carbon Stock Changes for REDD+ under the UNFCCC

International Journal of Forestry Research ◽

10.1155/2011/134526 ◽

2011 ◽

Vol 2011 ◽

pp. 1-13 ◽

Cited By ~ 14

Author(s):

Danae Maniatis ◽

Yadvinder Malhi ◽

Laurent Saint André ◽

Danilo Mollicone ◽

Nicolas Barbier ◽

...

Keyword(s):

Carbon Stock ◽

Measurement Data ◽

Forest Carbon ◽

Phase 2 ◽

Inventory Data ◽

Ecological Data ◽

Phase 3 ◽

Forest Carbon Stock ◽

Commercial Logging ◽

Commercial Forest

In the context of the adoption at the 16th Conference of the Parties in 2010 on the REDD+ mitigation mechanism, it is important to obtain reliable data on the spatiotemporal variation of forest carbon stocks and changes (called Emission Factor, EF). A re-occurring debate in estimating EF for REDD+ is the use of existing field measurement data. We provide an assessment of the use of commercial logging inventory data and ecological data to estimate a conservative EF (REDD+ phase 2) or to report on EF following IPCC Guidance and Guidelines (REDD+ phase 3). The data presented originate from five logging companies dispersed over Gabon, totalling 2,240 plots of 0.3 hectares.We distinguish three Forest Types (FTs) in the dataset based on floristic conditions. Estimated mean aboveground biomass (AGB) in the FTs ranges from 312 to 333 Mg ha−1. A 5% accuracy is reached with the number of plots put in place for the FTs and a low sampling uncertainty obtained (± 10 to 13 Mg ha−1). The data could be used to estimate a conservative EF in REDD+ phase 2 and only partially to report on EF following tier 2 requirements for a phase 3.

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