New article published in One Earth

My article on monitoring reforestation efforts in Chinese drylands using microwave remote sensing from QuikSCAT and solar-induced chlorophyll fluorescence from GOME-2 has been published in One Earth. This work was done in collaboration with an interdisciplinary team: Gretchen Keppel-Aleks at the University of Michigan, Feng Wang from the Chinese Academy of Sciences, Steve Frolking from the University of New Hampshire, and Denise Mauzerall from Princeton University. We find that both remote sensing data correlates strongly with official planting data from the Chinese government. We also compare different planting techniques: the “traditional” manual planting and the more recent trend of closing pastures to let vegetation recolonize the area naturally. Both methods appear to be successful. You can read the full article HERE (open access).

Title

Satellite Monitoring of Natural Reforestation Efforts in China’s Drylands

Abstract

Desertification in Northern China degrades air quality in China’s eastern cities by causing frequent dust storms. To stop desert expansion, China’s government initiated the Three-North Shelterbelt Program, a large-scale reforestation project. Many issues with the project have been raised, from the choice of ill-adapted species to planting methods. Recently, the government implemented “natural reforestation” – closing former pastures to let vegetation regrow naturally. Unfortunately, it has been difficult to estimate the large-scale success of natural reforestation because measuring arid ecosystem productivity is a challenge for optical remote sensing. Here, we use satellite data to monitor vegetation water content and photosynthetic activity, thereby quantifying changes in vegetation biomass and productivity in Northern China. These satellite data corroborate official reforestation data. Our results show that vegetation activity is strongly correlated with both natural and traditional active reforestation, indicating opportunities for new natural reforestation techniques combined with satellite monitoring in other semi-arid regions.

Science for Society

Climate change has been driving desertification in many parts of the world, from the southwestern United States to Sub-Saharan Africa. Deserts often encroach over arable land, reducing income for farmers and causing dust storms with large health impacts on the local population and global climate effects. Reforestation efforts protect the sand from being lifted by the wind, but these projects often fail because these areas are very dry, and the plants do not survive. Understanding how well different strategies work in this harsh environment is of global interest because many countries use reforestation as an official offset for their CO2 emissions. However, because of the mismatch between planted and surviving trees, the accounted carbon sequestered in these forests is overestimated. In this study, we use a new type of satellite data looking at vegetation water and photosynthesis to compare the success of different reforestation methods, using China’s Three-North Shelterbelt Program as a case study.

DOI: 10.1016/j.oneear.2019.12.015

Photo credits: Feng Wang


US-China Environment and Sustainability Forum

Two weeks ago, I presented a poster at the US-China Environment and Sustainability Forum organized by the SEAS department at the University of Michigan. The forum brought together experts from the US and China to take stock of achievements in addressing environmental and sustainability challenges in both countries, and identify critical areas that the two countries should work together and help the global transition towards more sustainable development. 

I had a chance to present my recent work on reforestation in Chinese drylands and you can access a high-resolution version of my poster HERE.

Photo credits: Ming Xu


Reforestation in China – preprint article out

My article on monitoring reforestation efforts in Chinese drylands using microwave remote sensing from QuikSCAT and solar-induced chlorophyll fluorescence from GOME-2 is available to read as a preprint on The Cell’s website. This work was done in collaboration with Gretchen Keppel-Aleks at the University of Michigan, Feng Wang from the Chinese Academy of Sciences, Steve Frolking from the University of New Hampshire, and Denise Mauzerall from Princeton University. We find that both remote sensing data correlates strongly with official planting data from the Chinese government. We also compare different planting techniques: the “traditional” manual planting and the more recent trend of closing pastures to let vegetation recolonize the area naturally. Both methods appear to be successful. Learn more by reading the full preprint HERE.

The paper is currently in revision and we are hoping that the final version will be available shortly! UPDATE: see the final paper out now in One Earth

Title

Satellite Monitoring of Natural Reforestation Efforts in China’s Drylands

Abstract

Desertification in Northern China degrades air quality in China’s eastern cities by causing frequent dust storms. To stop desert expansion, China’s government initiated the Three-North Shelterbelt Program, a large-scale reforestation project. Many issues with the project have been raised, from the choice of ill-adapted species to planting methods. Recently, the government implemented “natural reforestation” – closing former pastures to let vegetation regrow naturally. Unfortunately, it has been difficult to estimate the large-scale success of natural reforestation because measuring arid ecosystem productivity is a challenge for optical remote sensing. Here, we use satellite data to monitor vegetation water content and photosynthetic activity, thereby quantifying changes in vegetation biomass and productivity in Northern China. These satellite data corroborate official reforestation data. Our results show that vegetation activity is strongly correlated with both natural and traditional active reforestation, indicating opportunities for new natural reforestation techniques combined with satellite monitoring in other semi-arid regions.

Photo credits: Feng Wang


MUSE conference 2018

This week, I attended the Michigan University-wide Sustainability and Environment (MUSE) conference. Since arriving at the University of Michigan, I have been attending the MUSE bi-weekly workshops during which PhD students and postdocs give presentations or discuss articles on a range of topics related to sustainability and the environment.

The MUSE conference is a large-scale version of these workshops, bringing people from across the University of Michigan to present their research during a two-day event. I chaired the session on Land Use and Land Cover Change on Thursday morning and presented my own results from using solar-induced fluorescence to map reforestation in China.

It was a fun occasion to meet students, postdocs, and faculty from a range of departments, from English to Psychology, and Mechanical Engineering to the School of Public Health, and I hope that some of the contacts made at the conference will eventually turn into long-term collaborations.