Publications

Blue carbon refers to organic carbon sequestered by oceanic and coastal ecosystems. This stock has gained global attention as a high organic carbon repository relative to other ecosystems. Within blue carbon ecosystems, tidally influenced wetlands alone store a disproportionately higher amount of organic carbon than other blue carbon systems. North America harbors 42% of tidally...

Current estimates of wetland contributions to the global methane budget carry high uncertainty, particularly in accurately predicting emissions from high methane-emitting wetlands. Microorganisms drive methane cycling, but little is known about their conservation across wetlands. To address this, we integrate 16S rRNA amplicon datasets, metagenomes, metatranscriptomes, and annual methane...

Microbial processing of atmospheric nitrogen (N) deposition regulates the retention and mobilization of N in soils, with important implications for water quality. Understanding the links between N deposition, microbial communities, N transformations, and water quality is critical as N deposition shifts toward reduced N and remains persistently high in many regions. Here, we investigated...

A travois is crafted from one or more wooden poles and is one of the simplest pre-historic vehicles. Although these devices likely played vital roles in the lives of ancient peoples, they have low preservation potential in the archaeological record. Here we report linear features associated with human footprints, some of which are dated to ~22,000 years old, preserved in fine-grained...

The paleothermometer based on the alkenone unsaturation index (U37K′) is often used to reconstruct past sea surface temperatures (SST). In the SW Atlantic Ocean, however, a limited understanding of the seasonal and depth distribution of coccolithophores, which generates the U37K′ signal preserved in ocean sediments, hinders accurate estimates of past regional SSTs. We analyzed 45 core...

There are increasing global efforts and initiatives aiming to tackle climate change and mitigate its impacts via natural climate solutions (NCS). Wetlands have been considered effective NCS given their capacity to sequester and retain atmospheric carbon dioxide (CO2) while also providing a myriad of other ecosystem functions that can assist in mitigating the impacts of climate change...

Aim Increasing aridity has driven widespread synchronous fire occurrence in recent decades across North America. The lack of historical (pre-1880) fire records limits our ability to understand long-term continental fire-climate dynamics. The goal of this study is to use tree-ring reconstructions to determine the relationships between spatiotemporal patterns in historical climate and...

Pollen records from the unglaciated southeastern region of North America provide an overview of biogeographic changes associated with vegetational migration northward following the retreat of the Laurentide Ice Sheet. Changing insolation during the Holocene affected forest composition on the Coastal Plain, and rising sea level controlled the distribution of marsh and forested wetlands...

Climate-driven changes in high-elevation forest distribution and reductions in snow and ice cover have major implications for ecosystems and global water security. In the Greater Yellowstone Ecosystem of the Rocky Mountains (United States), recent melting of a high-elevation (3,091 m asl) ice patch exposed a mature stand of whitebark pine (Pinus albicaulis) trees, located ~180 m in...

Despite being long-lived and massive, giant sequoias (Sequoiadendron giganteum (Lindl.) J. Bucholz) are susceptible to erosion given their relatively shallow root structure. Human-caused soil compaction and vegetation loss through social trails are primary drivers of erosion in giant sequoia groves, particularly for trees that are near formal trails and access roads. We develop a method...

Mining and wildfires are both landscape disturbances that pose elevated and substantial hazards to water supplies and ecosystems due to increased erosion and transport of sediment, metals, and debris to downstream waters. The risk to water supplies may be amplified when these disturbances occur in the same watershed. This work describes mechanisms by which the intersection of mining and...

Urban vegetation is growing in importance as cities use 'green infrastructure' to mitigate the impacts of climate change, reduce extreme heat, and improve human health and comfort. However, due to the heterogeneity of city landscapes, urban vegetation experiences a diverse range of environmental conditions, potentially leading to differences in growing season timing and length within...