Geology topics

Emily J. Kachergis

Publications and source records attributed to Emily J. Kachergis.

3 recordsLinked to original sources

USGS2025

Sentinel-2 based estimates of rangeland fractional cover and canopy gap class for the western United States

Rangelands are extensive ecosystems, providing important ecosystem services while undergoing continuous change. As a result, improved monitoring technologies can help better characterize vegetation change. Satellite remote sensing has proven effective in this regard, tracking vegetation dynamics at broad and fine scales. We leveraged the spatial, spectral, and temporal resolution of Sentinel-2 satellites to estimate fractional cover and canopy gap across rangelands of the western United States. We produced annual, 10 m spatial resolution estimates of fractional cover and canopy gap size class for years 2018 to 2024. Fractional cover estimates include that of common plant functional types (annual forb and grass, bareground, littler, perennial forb and grass, shrub, tree) and select genera (including invasive annual grass species, pinyon-juniper species, and sagebrush species); canopy gap size classes include gap sizes 25 to 50, 51 to 100, 101 to 200, and greater than 200 cm. We make these data available as Cloud Optimized GeoTIFFs, organized as 75 × 75 km tiles covering the 17 western states of the United States.

western United States↗

USGS2025

Sentinel-2 based estimates of rangeland fractional cover and canopy gap class for the western United States

Rangelands are extensive ecosystems, providing important ecosystem services while undergoing continuous change. As a result, improved monitoring technologies can help better characterize vegetation change. Satellite remote sensing has proven effective in this regard, tracking vegetation dynamics at broad and fine scales. We leveraged the spatial, spectral, and temporal resolution of Sentinel-2 satellites to estimate fractional cover and canopy gap across rangelands of the western United States. We produced annual, 10 m spatial resolution estimates of fractional cover and canopy gap size class for years 2018 to 2024. Fractional cover estimates include that of common plant functional types (annual forb and grass, bareground, littler, perennial forb and grass, shrub, tree) and select genera (including invasive annual grass species, pinyon-juniper species, and sagebrush species); canopy gap size classes include gap sizes 25 to 50, 51 to 100, 101 to 200, and greater than 200 cm. We make these data available as Cloud Optimized GeoTIFFs, organized as 75×75 km tiles covering the 17 western states of the United States.

BioRxiv↗

USGS2024

Closing the conservation gap in the sagebrush biome: Spatial targeting and coordination are needed for conservation to keep pace with sagebrush losses

Core sagebrush areas (CSAs), patches of high sagebrush ecological integrity, continue to decline despite significant conservation and restoration investments across the sagebrush biome. Historically, conservation decisions in the biome have been driven by wildlife species-specific demands, but increasing recognition of the scale of threats and the pace of ecosystem degradation has compelled a shift towards threat-based ecosystem management. Therefore, there is a need to evaluate the scale of conservation implementation relative to the rate of degradation or loss from specific threats to the biome to assess whether a conservation deficit exists. To this end, we: 1) quantified and compared the average hectares of conservation practices implemented annually relative to the hectares of CSA loss attributed to each threat; 2) evaluated the relative amount of conservation actions in core sagebrush areas, growth opportunity areas, and other rangeland areas; and 3) assessed how much additional conservation may be needed to stop CSA declines. We then quantified how better spatial targeting and enhanced coordination might reduce the total additional amount of future conservation needed, and evaluated how an influx of resources can close the conservation gap, or the deficit between the conservation needed to offset annual loss and degradation and the capacity for conservation implementation. We found that current rates of conservation (e.g., hectares treated annually) are markedly lower than rates of CSA loss (∼10% of average annual loss). Furthermore, most conservation actions, ∼90% for some treatment types, occurred outside of CSAs likely reducing the efficacy of these conservation actions at retaining and restoring intact sagebrush rangelands. Additionally, we found that conservation efforts will need to increase by more than an order of magnitude (at least 10x) annually to halt CSA declines. However, through better spatial targeting of conservation actions, the increase in conservation needed to stop CSA loss could be reduced by 70% or more. This analysis demonstrates the divergent futures that may await the sagebrush biome pending key decisions regarding conservation targeting, stakeholder cooperation, and the strategic addition of resources.

Rangeland Ecology and Management↗