Full text: Technical Commission III (B3)

    
R C.Random sample 
ing with applications to 
raphy[J]. Communications 
Bethel, J., Mullen, R. 
etry, fifth ed. American 
mote Sensing. ISBN: |. 
ANSAC for live structure 
the IEEE International 
199-206. 
rammetry and Computer 
omatics and Information 
) 
tiple View Geometry in 
sity Press, 2003. 
Method to obtain UAV's 
sion [J]. Transducer and 
1). 
le relief automated image 
)1 
    
  
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B3, 2012 
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia 
INVESTIGATING THE DYNAMICS OF WANDOO CROWN DECLINE WITH TIME 
SERIES LANDSAT IMAGERY 
K. Zdunic® *, G. Behn? R. van Dongen * 
? DEC, GIS Branch, 17 Dick Perry Avenue Kensington, Australia - (Katherine.Zdunic, Graeme.Behn, 
Ricky.vanDongen) G dec.wa.gov.au 
KEY WORDS: Wandoo, Landsat, Time Series, Vegetation, Wandoo Crown Decline 
ABSTRACT: 
In the forests of south west Western Australia dramatic declines in tree health have been observed in recent years. The species 
Eucalyptus wandoo has exhibited loss of crown foliage in increasing stages of severity; this condition is referred to as wandoo crown 
decline and can lead to death. Determining the extent and timing of these declines is difficult on the ground due to the large 
distribution of E. wandoo and the observation of tree declines at a range of locations and dates over the last 40 years. Understanding 
the distribution, severity and timing of these declines is essential to the identification of the causes of these impacts. 
Investigation of time series Landsat imagery can inform on locations of crown foliage loss and the time periods these losses occurred 
in. Applying a vegetation index to a 20 year sequence of imagery enabled periods of decline to be identified. Employment of trend 
analysis of four date time series demonstrated the dynamics of wandoo crown cover. Comparisons of periods of decline with the 
variations of cover density over the entire image sequence facilitated the identification of possible locations and timing of wandoo 
crown decline impacts. Changes in crown cover observed by the imagery analysis were compared to field surveys. 
1. INTRODUCTION 
1.1 Motivation 
Over the last forty years Eucalyptus wandoo (wandoo) crowns 
have demonstrated varying losses in canopy initially on terminal 
branches in some cases leading to death. This is described as 
wandoo crown decline (WCD). The Wandoo Recovery Group 
was formed in 2003 to research, map and communicate the 
incidence of wandoo crown decline (Manning 2009). The 
Wandoo Recovery Group and others (Whitford er al 2010, 
Brown et al 1986, Mercer 1991, 2003, 2008) have done various 
field assessments examining the severity and extent of WCD. 
The geographic extent and access prohibit comprehensive 
evaluation across the entire wandoo occurrence. Lack of 
knowledge about the timing and spread of phenomenon makes it 
difficult to understand and manage. These issues have 
instigated the following questions: 
1) Where does wandoo crown decline (WCD) occur? 
2) In what time period does WCD occur? 
3) Isthere recovery from the decline? 
4) Isthe recovery to previous canopy cover? 
Time series satellite imagery can be utilised to inform these 
questions and improve understanding of WCD over the last 20 
years across its mapped occurrence. 
1.2 Eucalyptus wandoo 
Eucalyptus wandoo is an iconic tree of the Western Australian 
wheatbelt and is valued for its wood and form. It is endemic to 
the south west corner of Western Australia extending 500 
kilometres from Moora in the north to Mount Barker in the 
south along medium and low rainfall areas, generally 350- 
  
* Corresponding author. 
1000mm (figure 1) (Caphill 1984). The tree can grow up to 30 
metres high and achieve a girth of three metres, this reduces in 
lower rainfall zones (White and Manning, 2005). 
| 
| 
| 
| 
| 
WESTERN 
AUSTRALIA | 
| 
! 
= 
  
KULIN 
   
  
7%, MT BARKER 39 E 
  
7s, 
“og 800 Se 
isohyets (mm) TN 
5 0 50 100 
| Mapped Wandoo Occurrence 
Kilometers 
  
  
Figure 1. Locality of wandoo in south west Western Australia
	        
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