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Jon Wang (he/him)

@jonwang.bsky.social
1.2K followers 1.7K following 72 posts

Queer, Asian-American ecologist interested in global change. Wildfires, carbon, and land cover with remote sensing and machine learning. Leads the Dynamic Carbon and Ecosystems lab (www.dycelab.net) at the University of Utah.

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Jon Wang (he/him) @jonwang.bsky.social · 17/11/2024
Categories of fire severity (high vs low) are hard to interpret, and might miss climate trends. Remote sensing advances are revealing nuance across ecoregions (big expansion of fire in dense northern forests!). Hope this can improve wildfires observation, forest management, and ecosystem models! 6/7
Two maps of California, with varying shades of green indicating the amount of tree cover in each area. Burned areas indicated in orange for the first decade, 1986-1996, on the left and the last decade, 2011-2021, on the right. Fires are present, but modest in area, on the left. Fires are much larger in extent on the right, particularly in the northern forests.
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Jon Wang (he/him) @jonwang.bsky.social · 17/11/2024
Using a simple model of regional tree loss using burned area, fire severity, and forest exposure, we show that 47% (nearly half!) of observed tree losses can be attributed to increasing trends in fire severity and forest exposure. Climate warming will exacerbate this. 5/7
Line graph showing time on the x axis: year, 1985-2021 and cumulative tree loss in fire on the y axis. Lines and show the cumulative tree loss in modeling scenarios from 1985-2021 based on several scenarios. Black lines show the observed losses, reaching about 13,000 kilometers squared. The purple line represents a model scenario where fire severity is held constant, and it reaches about 10,000 kilometers squared. The red line shows the scenario where forest exposure is held constant, reaching about 8500 kilometers squared. The blue line shows the scenario where fire severity and forest exposure are held constant, and only burned area increases. It ends around 7500 kilometers squared.
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Jon Wang (he/him) @jonwang.bsky.social · 17/11/2024
Increased forest exposure suggests more dense forests are vulnerable to severe wildfire. In the last decade, wildfire moved in climate space, impacting forests adapted to moister, cooler environments that might have resisted disturbance. 4/7
Graph showing summer temperature on the x-axis and precipitation on the y-axis. Each climate bin is colored with the average tree cover (grey to green, 0 to 80%) occupying that part of climate space in California. Black points indicate the location in climate space of fires in the first decade. Blue indicates the same for the middle decade, and red for the last. Large points show the decadal average. The large blue and black points in are clustered around 20 degrees C and 750 mm precipitation. The large red point (last decade) is located at about 18 degrees C and 850 mm precipitation.
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Jon Wang (he/him) @jonwang.bsky.social · 17/11/2024
Average fire severity and forest exposure rose by 30% and 41%, respectively, from 1985-2021. The average tree cover loss per burned area used to be 20%, but recently it has been 34%, on average (+70%!). Increased burned area drives most tree loss, but is not the sole factor! 3/7
Four panels. First panel: line graph with red line showing increasing burned area, black line showing increasing tree cover loss from 1985-2021. Second panel: Average forest exposure (as points) and standard deviation (as lines) increasing steadily from 1985-2021. Third Panel: Average fire severity and standard deviation (again, points and lines) increasing steadily over 1985-2021. Fourth panel: the average and standard deviation of the combined effect of forest exposure and fire severity (tree cover loss), again as points and lines, showing steady increases from 1985-2021.
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Jon Wang (he/him) @jonwang.bsky.social · 06/07/2022
Tree losses were concentrated in the hottest parts of the state. As summer temperatures continue to climb, even more of California's forests will be threatened by wildfire and climate stress. 4/n
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Jon Wang (he/him) @jonwang.bsky.social · 06/07/2022
Tree cover dynamics (dark green line, top panel) varied widely geographically. Northern forests were impacted by harvest and recent fires, but recovered when it rained in the 90s. Rapidly warming southern forests might be losing their ability to recover from disturbance. 3/n
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Jon Wang (he/him) @jonwang.bsky.social · 06/07/2022
Forests are key in natural climate solutions but are threatened by disturbances like fire, making their viability uncertain. Since 1985, forest growth in CA can't keep up with recent extreme wildfire seasons, resulting in a net loss of tree cover by 6.7%. 2/n
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Jon Wang (he/him) @jonwang.bsky.social · 02/05/2022
Hi friends. I am overjoyed to share I will soon move to SLC/@UUtah to join @UofUBiology as an assistant professor in January 2023!! I still can't believe how fortunate I am. Much love and gratitude to mentors, friends, and colleagues over the last decade+!
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Jon Wang (he/him) @jonwang.bsky.social · 27/05/2021
Readyish for this interview.
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Jon Wang (he/him) @jonwang.bsky.social · 29/04/2021
In 2017, I visited the Northwest Territory and was shocked by how these truly huge forests are changing, how extensive the fire scars were. They'll require effort to protect and I'm honored to contribute my own carbon monitoring efforts to their conservation! Thanks everyone! 8/8
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Jon Wang (he/him) @jonwang.bsky.social · 29/04/2021
Finally, we compared our results to predictions from CMIP6 Earth system models, overestimated AGB growth by a factor of 3 due to the poor representation of fires. The models with red outlines represent fire processes, and the black ones lack fire processes. 7/8
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Jon Wang (he/him) @jonwang.bsky.social · 29/04/2021
We calibrated a regrowth model using chronosequence-derived average rates of AGB gain and loss due to fires and estimated the changing influence of fires on the AGB dynamics over longer timescales. These factors are far more important than variability in climate and CO2 6/8
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Jon Wang (he/him) @jonwang.bsky.social · 29/04/2021
Overall what we see is a modest net increase in AGB across the ABoVE domain. The dynamics of AGB growth, however, are heavily dominated by disturbances, and the net growth is cut by a third or so due to fires and harvest. 5/8
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Jon Wang (he/him) @jonwang.bsky.social · 29/04/2021
The long time series allowed us to track the dynamics of disturbance-driven losses and post-disturbance recovery on annual and decadal timescales. For example, here is a heavily harvested area in British Columbia. Apologies that the color scale changes! 4/8
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Jon Wang (he/him) @jonwang.bsky.social · 29/04/2021
The spatial detail allowed us to map the highly spatially heterogeneous distribution of boreal forest biomass across the 2.8 million km2 study domain. Shown are some examples of a fire-prone area (top row) and a heavily harvest area (bottom row) 3/8
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Jon Wang (he/him) @jonwang.bsky.social · 29/04/2021
By combining @usgslandsat time series with spaceborne lidar from ICESat, we mapped stocks and changes in aboveground biomass to better understand how disturbances impact carbon budgets. We want to understand what "greening" means in the far north. 2/8
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Jon Wang (he/him) @jonwang.bsky.social · 14/12/2020
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Jon Wang (he/him) @jonwang.bsky.social · 14/12/2020
Are you bready for this?
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Jon Wang (he/him) @jonwang.bsky.social · 27/08/2020
Summer reading.
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Jon Wang (he/him) @jonwang.bsky.social · 11/12/2019
Casualties of AGU: one fine seat post and saddle. I'm lucky that they left my rear light though!
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Jon Wang (he/him) @jonwang.bsky.social · 08/12/2019
I already feel exhausted! Lucky for me my talk is early - Monday morning 8:45am, B11D-04, Moscone West 3001 L3. Come bright and early to learn about biomass in boreal forests! #AGU2019
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Jon Wang (he/him) @jonwang.bsky.social · 12/10/2019
Airport dinner: soda and chips
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