scholarly journals Future scenarios of land-use and land-cover change in the United States--the Marine West Coast Forests Ecoregion

2012 ◽  
Author(s):  
Tamara S. Wilson ◽  
Benjamin M. Sleeter ◽  
Terry L. Sohl ◽  
Glenn Griffith ◽  
William Acevedo ◽  
...  
Keyword(s):  
United States ◽  
Land Use ◽  
Land Cover ◽  
Land Cover Change ◽  
West Coast ◽  
The United States ◽  
Future Scenarios

Spatial features of land use/land cover change in the United States

2003 ◽  
Vol 13 (1) ◽  
pp. 63-70 ◽  
Author(s):  
Zhiqiang Gao ◽  
Jiyuan Liu ◽  
Xiangzheng Deng
Keyword(s):  
United States ◽  
Land Use ◽  
Land Cover ◽  
Land Cover Change ◽  
The United States ◽  
Land Use Land Cover ◽  
Spatial Features

scholarly journals Effects of contemporary land-use and land-cover change on the carbon balance of terrestrial ecosystems in the United States

2018 ◽  
Vol 13 (4) ◽  
pp. 045006 ◽  
Author(s):  
Benjamin M Sleeter ◽  
Jinxun Liu ◽  
Colin Daniel ◽  
Bronwyn Rayfield ◽  
Jason Sherba ◽  
...  
Keyword(s):  
United States ◽  
Land Use ◽  
Land Cover ◽  
Land Cover Change ◽  
Carbon Balance ◽  
Terrestrial Ecosystems ◽  
The United States

scholarly journals Land cover change impacts on atmospheric chemistry: simulating projected large-scale tree mortality in the United States

2016 ◽  
Vol 16 (4) ◽  
pp. 2323-2340 ◽  
Author(s):  
Jeffrey A. Geddes ◽  
Colette L. Heald ◽  
Sam J. Silva ◽  
Randall V. Martin
Keyword(s):  
United States ◽  
Land Use ◽  
Air Quality ◽  
Land Cover ◽  
Land Cover Change ◽  
Dry Deposition ◽  
Large Scale ◽  
Tree Mortality ◽  
The United States ◽  
Tropospheric Chemistry

Abstract. Land use and land cover changes impact climate and air quality by altering the exchange of trace gases between the Earth's surface and atmosphere. Large-scale tree mortality that is projected to occur across the United States as a result of insect and disease may therefore have unexplored consequences for tropospheric chemistry. We develop a land use module for the GEOS-Chem global chemical transport model to facilitate simulations involving changes to the land surface, and to improve consistency across land–atmosphere exchange processes. The model is used to test the impact of projected national-scale tree mortality risk through 2027 estimated by the 2012 USDA Forest Service National Insect and Disease Risk Assessment. Changes in biogenic emissions alone decrease monthly mean O3 by up to 0.4 ppb, but reductions in deposition velocity compensate or exceed the effects of emissions yielding a net increase in O3 of more than 1 ppb in some areas. The O3 response to the projected change in emissions is affected by the ratio of baseline NOx : VOC concentrations, suggesting that in addition to the degree of land cover change, tree mortality impacts depend on whether a region is NOx-limited or NOx-saturated. Consequently, air quality (as diagnosed by the number of days that 8 h average O3 exceeds 70 ppb) improves in polluted environments where changes in emissions are more important than changes to dry deposition, but worsens in clean environments where changes to dry deposition are the more important term. The influence of changes in dry deposition demonstrated here underscores the need to evaluate treatments of this physical process in models. Biogenic secondary organic aerosol loadings are significantly affected across the US, decreasing by 5–10 % across many regions, and by more than 25 % locally. Tree mortality could therefore impact background aerosol loadings by between 0.5 and 2 µg m−3. Changes to reactive nitrogen oxide abundance and partitioning are also locally important. The regional effects simulated here are similar in magnitude to other scenarios that consider future biofuel cropping or natural succession, further demonstrating that biosphere–atmosphere exchange should be considered when predicting future air quality and climate. We point to important uncertainties and further development that should be addressed for a more robust understanding of land cover change feedbacks.

scholarly journals Land cover change impacts on atmospheric chemistry: simulating projected large-scale tree mortality in the United States

2015 ◽  
Vol 15 (20) ◽  
pp. 29303-29345
Author(s):  
J. A. Geddes ◽  
C. L. Heald ◽  
S. J. Silva ◽  
R. V. Martin
Keyword(s):  
United States ◽  
Land Use ◽  
Air Quality ◽  
Land Cover ◽  
Land Cover Change ◽  
Dry Deposition ◽  
Large Scale ◽  
Tree Mortality ◽  
The United States ◽  
Tropospheric Chemistry

Abstract. Land use and land cover changes impact climate and air quality by altering the exchange of trace gases between the Earth's surface and atmosphere. Large-scale tree mortality that is projected to occur across the United States as a result of insect and disease may therefore have unexplored consequences for tropospheric chemistry. We develop a land use module for the GEOS-Chem global chemical transport model to facilitate simulations involving changes to the land surface, and to improve consistency across land–atmosphere exchange processes. The model is used to test the impact of projected national-scale tree mortality risk through 2027 estimated by the 2012 USDA Forest Service National Insect and Disease Risk Assessment. Changes in biogenic emissions alone decrease monthly mean O3 by up to 0.4 ppb, but reductions in deposition velocity compensate or exceed the effects of emissions yielding a net increase in O3 of more than 1 ppb in some areas. The O3 response to emissions is controlled by the ratio of baseline NOx : VOC concentrations, suggesting that in addition to the degree of land cover change, tree mortality impacts depend on whether a region is NOx-limited or NOx-saturated. Consequently, air quality (as diagnosed by the number of days that average 8 h O3 exceeds 65 ppb) improves in polluted environments where changes in emissions are more important than changes to dry deposition, but worsens in clean environments where changes to dry deposition are the more important term. Biogenic secondary organic aerosol loadings are significantly affected across the US, decreasing by 5–10 % across many regions, and by more than 25 % locally. Tree mortality could therefore impact background aerosol loadings by between 0.5 to 2 μg m−3. Changes to reactive nitrogen oxide abundance and partitioning are also locally important. These simulations suggest that changes in biosphere–atmosphere exchange must be considered when predicting future air quality and climate. We point to important uncertainties and further development that should be addressed for a more robust understanding of land cover change feedbacks.

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