Remote sensing of Kangaroo Rat mound demographics and mound impacts on landscape processes in the northern Chihuahuan desert
Abstract
Large bare kangaroo rat mounds are common in deserts of the American southwest and have the potential for considerable impacts on landscape scale ecosystem processes including NPP, albedo, connectivity and hydrological dynamics. The methods to quantify kangaroo rat mounds and their ecosystem effects in the Jornada Basin LTER in the northern Chihuahuan Desert are using a combination of archival and current very high resolution (VHR) satellite imagery. The current imagery was obtained from the National Agriculture Imagery Program, with a spatial resolution of 1x1m and RBGnir spectral bands, which was captured May 2011. The contrasting imagery has a spatial resolution of 2.8x2.8m with one panchromatic band from February 1968, captured with the CORONA satellite. With the use of ArcGIS, manual delineation presents the percentage of both the mound and shrub cover.Here we use CORONA (1968, 2.8m resolution) and NAIP (2011, 1m resolution) imagery from the Jornada LTER to quantify and characterize kangaroo rat mounds through time. We find that although Kangaroo mound density remains relatively consistent throughout the 43-year time period, mound size decreases, mound orientation shifts, and mounds are consistently displaced by several meters. This phenomenon may be related to vegetation colonization potential around kangaroo rat mounds, and possibly by wind-driven movement of mound soils. To explore these local dynamics we classified the current and archival imagery of our study area into four categories: 1) kangaroo rat mounds, 2) bare ground, 3) shrubs, and 4) herbaceous vegetation. Preliminary results reveal that while percent cover of all classes remains relatively consistent, spatial distribution of bare ground and vegetation has notably changed through time. This suggests that Kangaroo rat mounds may be acting as local sources for wind driven erosion and bare patch expansion in the Chihuahuan desert.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMEP51C2099H
- Keywords:
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- 0439 Ecosystems;
- structure and dynamics;
- BIOGEOSCIENCES;
- 1804 Catchment;
- HYDROLOGY;
- 1815 Erosion;
- HYDROLOGY;
- 1824 Geomorphology: general;
- HYDROLOGY