Skip to main content
USGS - science for a changing world
Advanced Search

Filters: Tags: deserts (X)

478 results (56ms)   

View Results as: JSON ATOM CSV
thumbnail
We examined the content and isotopic composition of nitrogen within soils of a juniper woodland and found that a cryptobiotic crust composed of cyanobacteria, lichens, and mosses was the predominant source of nitrogen for this ecosystem. Disturbance of the crust has resulted in considerable spatial variability in soil nitrogen content and isotopic composition; intercanopy soils were significantly depleted in nitrogen and had greater abundance of 15N compared to intra-canopy soils. Variations in the 15N\14N ratio for inter- and intracanopy locations followed similar Rayleigh distillation curves, indicating that the greater 15N/14N ratios for inter-canopy soils were due to relatively greater net nitrogen loss. Coverage...
thumbnail
This metadata record describes the materials contained in stake folder 696. Stake 696 is located at latitude 36.39889, longitude -112.63056. This location was photographed in the following years: 1872, 1968 and 1972. The materials associated with this item include original best quality images from each repeat date (preserved as digitized film images or in some cases digitized print photographs, depending on availability), scanned film envelopes with camera metadata, records of repeat photography sheets, and all field notes and/or camera notes associated with this stake. All attachments follow the following naming convention: stake_date_material_type_Kanab. Some stakes will have multiple materials from one repeat...
thumbnail
This metadata record describes the materials contained in stake folder 713. Stake 713 is located at latitude 36.42478, longitude -112.63036. This location was photographed in the following years: 1872 and 1968. The materials associated with this item include original best quality images from each repeat date (preserved as digitized film images or in some cases digitized print photographs, depending on availability), scanned film envelopes with camera metadata, records of repeat photography sheets, and all field notes and/or camera notes associated with this stake. All attachments follow the following naming convention: stake_date_material_type_Kanab. Some stakes will have multiple materials from one repeat date...
thumbnail
This metadata record describes the materials contained in stake folder 2595. Stake 2595 is located at latitude 36.392, longitude -112.629. This location was photographed in the following years: 1942 and 1993. The materials associated with this item include original best quality images from each repeat date (preserved as digitized film images or in some cases digitized print photographs, depending on availability), scanned film envelopes with camera metadata, records of repeat photography sheets, and all field notes and/or camera notes associated with this stake. All attachments follow the following naming convention: stake_date_material_type_Kanab. Some stakes will have multiple materials from one repeat date (e.g.,...
thumbnail
This metadata record describes the materials contained in stake folder 1506. Stake 1506 is located at latitude 36.38585, longitude -112.63963. This location was photographed in the following years: 1909 (no physical image) and 1990. The materials associated with this item include original best quality images from each repeat date (preserved as digitized film images or in some cases digitized print photographs, depending on availability), scanned film envelopes with camera metadata, records of repeat photography sheets, and all field notes and/or camera notes associated with this stake. All attachments follow the following naming convention: stake_date_material_type_Kanab. Some stakes will have multiple materials...


map background search result map search result map A Break in the Nitrogen Cycle in Aridlands? Evidence from δ 15N of Soils USGS Southwest Repeat Photography Collection: Kanab Creek, southern Utah and northern Arizona, 1872-2010: Stake 1506 USGS Southwest Repeat Photography Collection: Kanab Creek, southern Utah and northern Arizona, 1872-2010: Stake 2595 USGS Southwest Repeat Photography Collection: Kanab Creek, southern Utah and northern Arizona, 1872-2010: Stake 0696 USGS Southwest Repeat Photography Collection: Kanab Creek, southern Utah and northern Arizona, 1872-2010: Stake 0713 USGS Southwest Repeat Photography Collection: Kanab Creek, southern Utah and northern Arizona, 1872-2010: Stake 1506 USGS Southwest Repeat Photography Collection: Kanab Creek, southern Utah and northern Arizona, 1872-2010: Stake 2595 USGS Southwest Repeat Photography Collection: Kanab Creek, southern Utah and northern Arizona, 1872-2010: Stake 0696 USGS Southwest Repeat Photography Collection: Kanab Creek, southern Utah and northern Arizona, 1872-2010: Stake 0713 A Break in the Nitrogen Cycle in Aridlands? Evidence from δ 15N of Soils