The program also welcomed Dr. Ariana Sutton-Grier as new Program Coordinator in July, 2022. Since then, Ariana has been busy learning all about all the incredible work done by the program and USGS; meeting the scientists, technicians, and managers behind it; and excitedly planning for the future. 

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Combining Paleoecolgical Data with Indigenous Knowledge

USGS scientists combined indigenous knowledge (IK) with empirical paleoecological data to document changes in forest conditions, climate, and fire patterns over long-time scales. 

The first study demonstrated the strong influence of Indigenous stewardship on forest conditions in northern California for at least a millennium where indigenous burning practices coupled with lightning-induced fires kept forest carbon low, at approximately half of what it is today, and hence forests were more open and less dense. These stable forest conditions appear to have enhanced the resiliency and health of the fire-prone forests of northern California. The study suggests that past indigenous management practices reduced fire risk and could be a model for modern management practices in California and for other fire-prone forests in the American West.  

Additionally, the study innovatively combined paleo data from pollen, tree fire scars, sedimentary charcoal, with IK from Karuk and Yurok oral histories. The study was possible through a close collaboration between scientists and tribal members who developed a research proposal that specified how they would honor tribal intellectual property, data sharing, and reciprocity requests. Tribal members contributed to the writing process and in workshops to share the findings once the study was published. This study process serves as a model for how scientists can work effectively and fairly with tribal members and incorporate IK with other scientific methods. 

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A second study used the North American Tree-ring Fire-scar Network dataset to examine 400 years of climate and fire history across the U.S. Southwest in addition to historical and archeological records. The team consulted and worked with indigenous communities including the Navajo Nation and the Pueblo of Jemez. They found that indigenous burning practices helped buffer the influence of climate on fire at local scales during the study time period from 1500 to 1900. While climate conditions were the dominant factor controlling wildfire across the region, at the local scale, indigenous cultural burning practices helped weaken the climate-fire link, as regular burning kept fuel levels low. The results suggest that controlled burning may be able to mitigate the influence of wildfires at local levels as it did in the past.

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Investigating Green Infrastructure and Heat Mitigation

USGS researchers looked at the contribution of urban land cover to air temperature in Denver, CO, to better understand the drivers of urban heat and urban heat mitigation. They found that urban land cover accounts for 17% of the variation in local air temperature during the day and 25% of the variation in local air temperature at night. Tree and turf cover reduce air temperatures more than impervious surfaces such that adding tree canopy can provide the largest magnitude of heat mitigation, because of the cooling effect.

This work improves our understanding and ability to predict when and where in urban areas extreme heat may be a problem and how to mitigate it which has important public health implications. This study also has important social equity and environmental justice implications because lower income communities, which is where underrepresented minorities are more likely to live, tend to have fewer trees and less “green infrastructure.” Hence these communities are less likely to have the natural infrastructure to combat the urban extreme heat due to climate change, thus equity and environmental justice concerns can and should be considered in future management and planning decisions for where to make urban investments in trees and other green infrastructure.

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Tree Mortality Events and Increased Temperatures

Forests have the potential to be a very important natural climate mitigation opportunity. Trees take up carbon and store that carbon as plant biomass. Therefore, reforestation and urban forestry in addition to maintaining the health of our existing forests are all good nature-based strategies for mitigating some of our nation’s greenhouse gas emissions.

However, as documented in a recent study by USGS scientists and colleagues, large-scale and severe tree mortality events have begun to emerge worldwide as a consequence of increased temperatures and drought. This is particularly concerning, as many of these ecosystems had previously been considered either tolerant of these extreme conditions or not at risk of exposure. This raises concerns about climate change risks to the health of forests around the world; climate change may affect forests and their ability to provide desired benefits including carbon sequestration. In response, USGS researchers and their collaborators are working to develop tools to aid forest managers in targeting treatments to increase forest resilience. Of note, the paper was honored as one of the top 50 downloads from 2022 across all of the publisher’s (Annual Reviews) 51 journals.

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Monitoring Coastal Wetlands' Resilience

Coastal wetlands can reduce storm and erosion risk, but sea-level rise is threatening the long-term health and survival of coastal wetlands in the U.S. In one recent study, USGS scientists and colleagues determined that marshes in the Holocene to today could generally keep pace with rates of sea-level rise below 5mm per year, but that there is a breakpoint between 5- and 10-mm per year, where marshes are not likely to be able to accrete enough sediment to keep up with sea-level rise. These rates of sea-level rise are anticipated to occur by mid-century under high emissions climate scenarios and have already been reached in some subsiding deltas occupied by tidal marshes. Under these circumstances, tidal marsh survival will increasingly depend on their ability to migrate landward.

Furthermore, in another recent study USGS scientists and colleagues determined that even with landward migration, the U.S. is still likely to lose some of its coastal wetland area due to constraints on where wetlands can move and rates of sea-level rise that may be too fast for some wetlands to keep pace. As wetlands are lost, society will lose the benefits wetlands provide including storm and erosion risk reduction.

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Increasing Summer Temperatures in the U.S. Southwest and Ecological Consequences

Lichens, moss and bacteria form a biological soil crust that protects desert ecosystems by helping to prevent erosion, increasing water retention and creating a nutrient rich growing environment. USGS scientists analyzed 24 years of biological soil crust data to look at the effects of climate change of desert soils and ecosystems in Canyonlands National Park, Utah. The data indicate that conditions may be increasingly inhospitable to native biocrust organisms, and could be an early indicator that desert soil crusts are at a tipping point. Loss of these biological soil crusts would mean the loss of a protective layer exposing the soils to more erosion and also leading to potential declines in biodiversity of plant and animal species since the biocrusts play an important role in nitrogen fixation to create fertile soils.

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Understanding Physical Processes that Control Glacier Change

Glaciers are dynamic landscape features that are changing rapidly in response to climate forcing. The flow of glacier ice is closely coupled not only to climate, but also glacier geometry. In 2022, USGS scientists worked with university collaborators to combine remote sensing data with direct field measurements to advance understanding of the complex interplay between mountain glacier ice flow, ice thinning, and climate change. This science enhances predictive capacity, improving stakeholder ability to anticipate and respond to the downstream consequences and ecosystem transformation caused by glacier change.

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Conveying Glacier Data to Domestic and International Stakeholders

USGS scientists are expanding the relevance of the Benchmark Glacier network by combining new technologies with decades of direct glaciological studies to deliver key science to a world adapting to rapid glacier loss. Like the Greenland or Antarctic ice sheets, mountain glacier melt contributes to global average sea level rise. Leveraging high performance computing and satellite imagery, scientists are monitoring glaciers and researching glacial processes across diverse climatic zones, providing a holistic understanding of glacier change needed for adaptive water resource strategies.

For over six decades the Benchmark Glacier Project has coordinated intensive glacier field research to better understand the physics that control glacier dynamics, the connection between climate and glaciers, and the downstream impacts of glacier loss. Understanding glacier change on regional scales using direct field measurements and remotely sensed data allows the USGS Benchmark Project to provide actionable information for downstream science and stakeholders. This includes other scientists focused on species habitat, ecosystem function, glacier geophysics, oceanography, and resource management. To communicate this work and its importance, the team recently published a factsheet and interactive geonarrative.

USGS scientists collect weather station data near glacier sites and maintain internationally valued glaciological records. These data are made available to the public annually via USGS publication and the World Glacier Monitoring Service.