Spatial conservation prioritization in the Swan Region - a pilot study using Marxan

Cristina Estima Ramalho, Geoff Barrett, Brett Glossop, David Mitchell, Barbara Wilson, Karen Clarke

Research output: Book/ReportScholarly edition


In this pilot study, we have used a systematic conservation planning approach in order to address four questions of major importance to the Department of Parks and Wildlife (DPaW) Swan Region: To what extent does the current DPaW managed IUCN I-IV conservation reserve network provide sufficient protection to the main conservation assets identified in the Swan Region? What other areas in the Swan Region should be prioritized for conservation and considered for integration in the DPaW managed IUCN I-IV conservation reserve network, given their conservation assets? Within the current DPaW managed IUCN I-IV conservation reserve network, what areas should be prioritized for allocation of limited management and restoration resources? How does recently acquired land quantitatively improve the conservation ability of the DPaW managed IUCN I-IV conservation reserve network?
The conservation planning software Marxan was used to examine the above questions. The use of this software involved the following main steps: 1) identification and compilation of the conservation assets present in the Swan Region (total of 409 conservation features used, grouped in nine major groups); 2) subdivision of the region into a series of planning units; 3) quantification of the amount of each conservation asset found in each planning unit; 4) establishment of targets for each conservation asset that ensure their adequate conservation in the Swan Region and; 5) application of an annealing algorithm that iteratively selects a set of planning units which meets the conservation targets in the most efficient manner.
The primary results of this study include: Most conservation features are under-represented in the DPaW managed IUCN I-IV conservation reserve network. Among the conservation features considered, those more poorly represented include the vegetation complexes, the threatened, specially protected, and priority fauna species, and to a smaller extent, the threatened and priority flora species. The conservation features better represented in the reserve network include the threatened and priority ecological communities, and the nationally important wetlands and RAMSAR wetlands. Five major zones in the Swan Region were identified as having relatively large patches of remnant vegetation with high irreplaceable value and that are not protected by the DPaW IUCN I-IV conservation reserves. The areas within these zones should be prioritized and considered for future integration into the IUCN I-IV conservation reserve network. They include: Zone A - remnant vegetation east of Seabird and south of Guilderton; in the Gnangara-Moore river State Forest; north of Muchea; and in the north to southeast surroundings of Wanneroo; Zone B - remnant vegetation north to east of Avon Valley National Park; Zone C - remnant vegetation north to southwest of Forrestdale; along the Serpentine river; and between Rockingham and Singleton; Zone D - remnant vegetation east of Yalgorup National Park; Zone E - remnant vegetation between Boddington and Westdale. Some of these areas are State forests, classified as IUCN VI conservation reserves. However, their very high irreplaceable value, as identified in this study, suggests that they should receive greater protection and be integrated into the IUCN I-IV conservation reserve network. More than half of the DPaW managed IUCN I-IV conservation lands (approximately 160 000 ha) had high irreplaceable value, with a selection frequency >70%. On the Swan Coastal Plain, most DPaW managed IUCN I-IV conservation reserves had very high irreplaceable value across their entire area, whereas in the Darling Range, there was a full spectrum of selection frequencies across and within the different reserves. While this analysis potentially provides a spatial framework for prioritization of areas for allocation of management and restoration resources within the DPaW managed IUCN I-IV conservation reserve network, it is highly dependent on the biological records’ spatial accuracy and evenness of survey effort across and within reserves. Integration of five parcels of remnant vegetation totalling 8 005 ha would increase the area of the DPaW IUCN I-IV conservation reserves network by 4% and would benefit 16 of the 409 conservation features considered in the study. Among these 16 conservation features, the Dwarf Pea plant Ptychosema pusillum and the Caladenia vegetation complex would receive most benefit, with a gain of 33% and 32% in achieved target, respectively. 
This analysis showed how Marxan can be used as a tool for assessing the return on investment in land being considered for acquisition by the DPaW.The results of this study are preliminary and should be interpreted and applied cautiously given identified insufficient dataset cleansing and other caveats mentioned in the report. Nevertheless, the study demonstrates the value of a systematic conservation planning approach as a framework to support decision-making for spatial planning and reserve management in the complex, rapidly urbanizing, and highly biodiverse Swan Region.
Original languageEnglish
Place of PublicationPerth, Australia
Publication statusPublished - 2013


Dive into the research topics of 'Spatial conservation prioritization in the Swan Region - a pilot study using Marxan'. Together they form a unique fingerprint.

Cite this