Limits...
Rangeland Condition Monitoring: A New Approach Using Cross-Fence Comparisons of Remotely Sensed Vegetation.

Kilpatrick AD, Lewis MM, Ostendorf B - PLoS ONE (2015)

Bottom Line: We interpret this wealth of data using a cross-fence comparison methodology, allowing us to rank paddocks (fields) in the study region according to effectiveness of grazing management.While no paddocks had a known increase in stocking rate during the study period, many had a reduction or complete removal in stock numbers, and many also experienced removals of pest species, such as rabbits, and other ecosystem restoration activities.These paddocks generally showed an improvement in rank compared to paddocks where the stocking regime remained relatively unchanged.

View Article: PubMed Central - PubMed

Affiliation: School of Biological Sciences, The University of Adelaide, Adelaide, Australia.

ABSTRACT
A need exists in arid rangelands for effective monitoring of the impacts of grazing management on vegetation cover. Monitoring methods which utilize remotely-sensed imagery may have comprehensive spatial and temporal sampling, but do not necessarily control for spatial variation of natural variables, such as landsystem, vegetation type, soil type and rainfall. We use the inverse of the red band from Landsat TM satellite imagery to determine levels of vegetation cover in a 22,672 km(2) area of arid rangeland in central South Australia. We interpret this wealth of data using a cross-fence comparison methodology, allowing us to rank paddocks (fields) in the study region according to effectiveness of grazing management. The cross-fence comparison methodology generates and solves simultaneous equations of the relationship between each paddock and all other paddocks, derived from pairs of cross-fence sample points. We compare this ranking from two image dates separated by six years, during which management changes are known to have taken place. Changes in paddock rank resulting from the cross-fence comparison method show strong correspondence to those predicted by grazing management in this region, with a significant difference between the two common management types; a change from full stocking rate to light 20% stocking regime (Major Stocking Reduction) and maintenance of full 100% stocking regime (Full Stocking Maintained) (P = 0.00000132). While no paddocks had a known increase in stocking rate during the study period, many had a reduction or complete removal in stock numbers, and many also experienced removals of pest species, such as rabbits, and other ecosystem restoration activities. These paddocks generally showed an improvement in rank compared to paddocks where the stocking regime remained relatively unchanged. For the first time, this method allows us to rank non-adjacent paddocks in a rangeland region relative to each other, while controlling for natural spatio-temporal variables such as rainfall, soil type, and vegetation community distributions, due to the nature of the cross-fence experimental design, and the spatially comprehensive data available in satellite imagery. This method provides a potential tool to aid land managers in decision making processes, particularly with regard to stocking rates.

Show MeSH

Related in: MedlinePlus

Spatial representation of change in paddock rankings between November 2002 and October 2008.Positive numbers are paddocks with increased ranking, whilst negative numbers are paddocks with a reduced ranking. Changes of +/- 5 in rank between the two dates are considered to be minor and not significant. Shadings denote positive (light), no significant change, and negative changes (dark).
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4643980&req=5

pone.0142742.g005: Spatial representation of change in paddock rankings between November 2002 and October 2008.Positive numbers are paddocks with increased ranking, whilst negative numbers are paddocks with a reduced ranking. Changes of +/- 5 in rank between the two dates are considered to be minor and not significant. Shadings denote positive (light), no significant change, and negative changes (dark).

Mentions: Fig 4c and 4d show the cross-fence comparison ranking for the two image dates. Most paddocks change in rank between these two dates. Fig 5 displays the change in rank between 2002 and 2008, showing the spatial distribution of change with relation to station boundaries and this can be compared spatially to the management regimes shown in Fig 2. The rank change is not uniform within station boundaries, with some stations showing more heterogeneity than others. Overall the majority of stations show a general uniformity in their rank behaviour. General increases in rank occur in the pastoral stations of Andamooka (MSR), Roxby Downs (MSR) and Purple Downs (MSR), as well as the Olympic Dam Town (CSR) and Mine Leases (CSR). The Arid Recovery Reserve (ER) also shows an overall positive increase in ranking, with three paddocks showing an increase, while the remainder show no significant difference. Pastoral stations with an overall neutral or minor change in rank are Billa Kalina (FSM) and Stuart Creek (MSR). Pastoral stations with an overall decrease in rank are Parakylia (FSM), Mulgaria (FSM), Coondambo (FSM), and also the Wabma Kadarbu Conservation Park (CSR).


Rangeland Condition Monitoring: A New Approach Using Cross-Fence Comparisons of Remotely Sensed Vegetation.

Kilpatrick AD, Lewis MM, Ostendorf B - PLoS ONE (2015)

Spatial representation of change in paddock rankings between November 2002 and October 2008.Positive numbers are paddocks with increased ranking, whilst negative numbers are paddocks with a reduced ranking. Changes of +/- 5 in rank between the two dates are considered to be minor and not significant. Shadings denote positive (light), no significant change, and negative changes (dark).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4643980&req=5

pone.0142742.g005: Spatial representation of change in paddock rankings between November 2002 and October 2008.Positive numbers are paddocks with increased ranking, whilst negative numbers are paddocks with a reduced ranking. Changes of +/- 5 in rank between the two dates are considered to be minor and not significant. Shadings denote positive (light), no significant change, and negative changes (dark).
Mentions: Fig 4c and 4d show the cross-fence comparison ranking for the two image dates. Most paddocks change in rank between these two dates. Fig 5 displays the change in rank between 2002 and 2008, showing the spatial distribution of change with relation to station boundaries and this can be compared spatially to the management regimes shown in Fig 2. The rank change is not uniform within station boundaries, with some stations showing more heterogeneity than others. Overall the majority of stations show a general uniformity in their rank behaviour. General increases in rank occur in the pastoral stations of Andamooka (MSR), Roxby Downs (MSR) and Purple Downs (MSR), as well as the Olympic Dam Town (CSR) and Mine Leases (CSR). The Arid Recovery Reserve (ER) also shows an overall positive increase in ranking, with three paddocks showing an increase, while the remainder show no significant difference. Pastoral stations with an overall neutral or minor change in rank are Billa Kalina (FSM) and Stuart Creek (MSR). Pastoral stations with an overall decrease in rank are Parakylia (FSM), Mulgaria (FSM), Coondambo (FSM), and also the Wabma Kadarbu Conservation Park (CSR).

Bottom Line: We interpret this wealth of data using a cross-fence comparison methodology, allowing us to rank paddocks (fields) in the study region according to effectiveness of grazing management.While no paddocks had a known increase in stocking rate during the study period, many had a reduction or complete removal in stock numbers, and many also experienced removals of pest species, such as rabbits, and other ecosystem restoration activities.These paddocks generally showed an improvement in rank compared to paddocks where the stocking regime remained relatively unchanged.

View Article: PubMed Central - PubMed

Affiliation: School of Biological Sciences, The University of Adelaide, Adelaide, Australia.

ABSTRACT
A need exists in arid rangelands for effective monitoring of the impacts of grazing management on vegetation cover. Monitoring methods which utilize remotely-sensed imagery may have comprehensive spatial and temporal sampling, but do not necessarily control for spatial variation of natural variables, such as landsystem, vegetation type, soil type and rainfall. We use the inverse of the red band from Landsat TM satellite imagery to determine levels of vegetation cover in a 22,672 km(2) area of arid rangeland in central South Australia. We interpret this wealth of data using a cross-fence comparison methodology, allowing us to rank paddocks (fields) in the study region according to effectiveness of grazing management. The cross-fence comparison methodology generates and solves simultaneous equations of the relationship between each paddock and all other paddocks, derived from pairs of cross-fence sample points. We compare this ranking from two image dates separated by six years, during which management changes are known to have taken place. Changes in paddock rank resulting from the cross-fence comparison method show strong correspondence to those predicted by grazing management in this region, with a significant difference between the two common management types; a change from full stocking rate to light 20% stocking regime (Major Stocking Reduction) and maintenance of full 100% stocking regime (Full Stocking Maintained) (P = 0.00000132). While no paddocks had a known increase in stocking rate during the study period, many had a reduction or complete removal in stock numbers, and many also experienced removals of pest species, such as rabbits, and other ecosystem restoration activities. These paddocks generally showed an improvement in rank compared to paddocks where the stocking regime remained relatively unchanged. For the first time, this method allows us to rank non-adjacent paddocks in a rangeland region relative to each other, while controlling for natural spatio-temporal variables such as rainfall, soil type, and vegetation community distributions, due to the nature of the cross-fence experimental design, and the spatially comprehensive data available in satellite imagery. This method provides a potential tool to aid land managers in decision making processes, particularly with regard to stocking rates.

Show MeSH
Related in: MedlinePlus