Research sponsored by the USGS Land Change Science (LCS) Program supported development and deployment of an innovative sensor system aimed at enabling improved, near-surface multispectral imaging and monitoring of vegetation seasonality and landscape condition.
Ecosystems - Vegetation
Crop residues play an important role in agricultural conservation, serving as a protective layer on agricultural fields, shielding soil from wind and water, preventing erosion, reducing moisture loss, and increasing soil carbon storage. Accurate assessment of the extent of crop residue is necessary for tracking the implementation of conservation tillage practices. Traditionally, residue is assessed using in-field observations. However, these methods are not cost-effective over large land areas.
Freshwater wetlands are an important habitat type and valued landscape at Fort A.P. Hill, located 70 miles east of Washington, D.C., in Caroline County, northeast Virginia. Of approximately 75,000 acres of land comprising the Fort, about 8.5% (6,385 acres) are freshwater wetlands. The mapping project utilized two-dimensional interpretation of 1-foot color-infrared orthorectified imagery collected in 2013, affording greater detail in wetland interpretation and classification.
The dynamics of coastal marsh dieback, recovery and loss are documented using a combination of optical and radar remotely sensed data. Landsat Thematic Mapper (TM) and Satellite Pour l'Observation de la Terre (SPOT) satellite-based optical sensors, NASA Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR), and field data captured the occurrence of and recovery from an undetected dieback of wetland vegetation between the summers of 2010, 2011, and 2012 in the Spartina alterniflora marshes of coastal Louisiana.
Remote Sensing of Vegetation and Aquatic Parameters for Modeling Coastal Marsh Response to Sea-Level Rise
With funding from the NASA Applied Sciences Program, the USGS partnered with the NOAA National Estuarine Research Reserve System (NERRS) to develop a remote sensing-based forecasting model of tidal marsh response to sea-level rise to address the potential impacts of sea-level rise on coastal ecosystems and dependent wildlife species. The Marsh Equilibrium Model (MEM) is a one-dimensional mechanistic model of marsh elevation change based on feedbacks between field-measured organic (plant biomass) and inorganic (suspended sediment) inputs.
Lidar can be problematic for mapping topography of coastlines because it is infeasible to fly large areas during short low-tide intervals and capture intertidal coverage. As an alternative, USGS and Oregon State University researchers used terrestrial laser scanning (TLS) at an Oregon rocky intertidal site to investigate potential changes in foraging habitat for an obligate intertidal shorebird, black oystercatcher, using several sea-level rise scenarios. Researchers used TLS-derived topography to model and identify ideal oystercatcher foraging habitat.
The effective implementation of agricultural conservation practices is critical to the improvement of water quality in the Chesapeake Bay region, where non-point sources of nutrients, sediment, and agrichemicals are major contributors to water quality impairment. The use of winter cover crops, for example, has been identified as a key conservation management practice for reducing the loss of nitrogen and sediment from agricultural lands. However, the effectiveness of conservation practices varies widely depending on landscape, climate, and agronomic management.
Ecosystems - Wildlife
Bat fatalities at wind turbines peak during low wind conditions and primarily involve tree-roosting bats. To investigate the reason for this pattern, USGS researchers and colleagues used thermal surveillance cameras, near-infrared video, acoustic detectors, and radar to monitor bat behavior at a wind farm in Indiana from July to October 2012. During periods of low wind, more bats approached turbines than during periods of high wind. As wind speeds increased, bats more frequently approached turbines from a downwind direction, but only when turbine blades were not turning.
Whooping cranes (Grus americana) migrate twice each year through the Great Plains in North America. Recovery activities for this endangered species include providing adequate places to stop and rest during migration. USGS scientists have made initial estimates of stopover site use intensity, which has allowed researchers to identify areas across the migration range receiving proportionally greater use by whooping cranes.
The USGS Fort Collins Science Center (FORT) worked with the U.S. Fish and Wildlife Service (FWS) to revise the California condor global positioning system (GPS) data acquisition, management, and archive workflow. FORT and the FWS implemented a Global System for Mobile Communication (GSM) GPS tracking system, a relatively economical cellular technology. The devices stream positional data to an online system that manages transmitter/bird deployment data and proofs incoming GPS data.