Spatiotemporal mapping of the dry season vegetation response of sagebrush steppe

The vegetation dynamics of semi-arid and arid landscapes are temporally and spatially heterogeneous and subject to various disturbance regimes that act on decadal scales. Traditional field-based monitoring methods have failed to sample adequately in time and space in order to capture this heterogeneity and thus lack the spatial extent and the long-term continuous time series of data necessary to detect anomalous dynamics in landscape behavior. Time series of ecological indicators of land degradation that are collected synoptically from local to global spatial scales can be derived from the 33-year and continuing Landsat satellite archive. Consequently, a retrospective study was conducted on a commercially grazed sagebrush steppe dominated Utah landscape using a time series of standardized Landsat imagery for the period 1972 to 1997. The study had the objectives to (1) characterize and map the historical trends of a remotely-sensed index of vegetation response, a correlate of vegetation cover or phytomass, and (2) to retrospectively infer the cause of this response to historical records of grazing and wet and drought periods. A time series of dry season vegetation index maps were statistically clustered to generate a spatio-temporal map of three coarse trends of vegetation response, i.e., declining, stable, and increasing trends. This study showed that 71% of the landscape’s locations had an increasing trend and 29% had a stable trend over the 26-year period. The increasing trend locations were positively correlated with site water balance [the Palmer Drought Severity Index (PDSI)], i.e., vegetation response increased during wet periods and decreased during drought. The increasing trend was positively and negatively (non-linearly) correlated with grazing in individual paddocks from 1980 to 1997.

[1]  D. H. Knight,et al.  Mountains and Plains: The Ecology of Wyoming Landscapes , 1996 .

[2]  B. Wylie,et al.  Satellite mapping of surface biophysical parameters at the biome scale over the North American grasslands a case study , 2002 .

[3]  M. Scheffer,et al.  El Niño effects on the dynamics of terrestrial ecosystems. , 2001, Trends in ecology & evolution.

[4]  W. Bowman.  Mountains and Plains , 1997 .

[5]  Halka Chronic,et al.  Roadside Geology of Utah , 1980 .

[6]  Thomas A. Spies,et al.  Dynamics and Pattern of a Managed Coniferous Forest Landscape in Oregon , 1994 .

[7]  S. Ustin,et al.  Remote sensing of soil properties in the Santa Monica mountains I. Spectral analysis , 1998 .

[8]  J. Magnuson.  Long-Term Ecological Research and the Invisible Present , 1990 .

[9]  W. Fuller,et al.  Distribution of the Estimators for Autoregressive Time Series with a Unit Root , 1979 .

[10]  Karin E. Callahan.  VALIDATION OF A RADIOMETRIC NORMALIZATION PROCEDURE FOR SATELLITE DERIVED IMAGERY WITHIN A CHANGE DETECTION FRAMEWORK , 2003 .

[11]  W. Laycock.  Stable states and thresholds of range condition on North American rangelands: a viewpoint. , 1991 .

[12]  James Bethel,et al.  ISPRS journal of photogrammetry and remote sensing, report for the period 1996-2000 , 2000 .

[13]  John R. Jensen,et al.  Introductory Digital Image Processing: A Remote Sensing Perspective , 1986 .

[14]  Paul Newbold,et al.  Spurious regressions in econometrics , 2001 .

[15]  A. Huete.  A soil-adjusted vegetation index (SAVI) , 1988 .

[16]  Gordon B. Bonan,et al.  Ecological Climatology: Concepts and Applications , 2002 .

[17]  John A. Wiens,et al.  Landscape mosaics and ecological theory , 1995 .

[18]  W. Alley.  The Palmer Drought Severity Index: Limitations and Assumptions , 1984 .

[19]  J. C. Winslow,et al.  Numerical Terradynamic Simulation Group 3-2001 Mapping Weekly Rangeland Vegetation Productivity Using MODIS Algorithms , 2018 .

[20]  Dale R. Lockwood,et al.  Catastrophe theory: a unified paradigm for rangeland ecosystem dynamics. , 1993 .

[21]  Monnie McGee,et al.  Introduction to Time Series Analysis and Forecasting: With Applications of SAS and SPSS , 2000 .

[22]  Stanley A. Schumm,et al.  To interpret the earth : ten ways to be wrong , 1992 .

[23]  J. Holechek,et al.  An approach for setting the stocking rate. , 1988 .

[24]  S. Goetz,et al.  Radiometric rectification - Toward a common radiometric response among multidate, multisensor images , 1991 .

[25]  R. Pech,et al.  The assessment and monitoring of sparsely vegetated rangelands using calibrated Landsat data , 1988 .

[26]  Angela Lee,et al.  Perspectives on … Environmental Systems Research Institute, Inc , 1997 .

[27]  C. B. Hunt.  Natural regions of the United States and Canada , 1973 .

[28]  Patrick Hostert,et al.  Retrospective studies of grazing-induced land degradation: A case study in central Crete, Greece , 2003 .

[29]  Craig Loehle,et al.  Optimal stocking for semi-desert range: A catastrophe theory model , 1985 .

[30]  R. Hobbs,et al.  Key issues and research priorities in landscape ecology: An idiosyncratic synthesis , 2002, Landscape Ecology.

[31]  P. Sellers.  Canopy reflectance, photosynthesis and transpiration , 1985 .

[32]  G. Pickup,et al.  Use of landsat radiance parameters to distinguish soil erosion, stability, and deposition in arid Central Australia , 1984 .

[33]  R. D. Ramsey,et al.  Change detection of the effect of severe drought on subsistence agropastoral communities on the Bolivian Altiplano , 1998 .

[34]  Paulien Hogeweg,et al.  Computing an organism: on the interface between informatic and dynamic processes. , 2002, Bio Systems.

[35]  I. Noy-Meir,et al.  Desert Ecosystems: Environment and Producers , 1973 .

[36]  I. Noy-Meir,et al.  Stability of Grazing Systems: An Application of Predator-Prey Graphs , 1975 .

[37]  W. Bastiaanssen.  Remote sensing in water resources management: the state of the art. , 1998 .

[38]  Glenn W. Suter,et al.  Ecological risk assessment , 2006 .

[39]  N. Kalouptsidis,et al.  Spectral analysis , 1993 .

[40]  T. V. Niel,et al.  Classification of Vegetation and Analysis of its Recent Trends at Camp Williams, Utah Using Remote Sensing and Geographic Information System Techniques , 1995 .

[41]  J. L. Barker,et al.  Landsat MSS and TM post-calibration dynamic ranges , 1986 .

[42]  B. Frazier,et al.  Remote sensing of soils in the eastern Palouse region with Landsat Thematic Mapper , 1989 .