Marxan is a conservation planning software that allows a systematic approach to the design of efficient conservation areas.
Marxan is a suite of tools designed to help decision makers find good solutions to conservation planning problems. Initially designed to address conservation area design goals where a benchmark representation of biodiversity was required at the smallest cost possible. These tools has been applied to hundreds of spatial conservation planning problems around the world.
This tool is primarily a product of Ian Ball's PhD thesis (Ball 2000). In the initial stages, it was called SPEXAN, a combination of the words Spatially Explicit Annealing. Marxan was developed as a modified version of SPEXAN to meet the needs of the Great Barrier Reef Marine Planning Authority (GBRMPA) in their 2003-2004 rezoning plans. The US National Marine Fisheries Service (NMFS) have funded further advancement of Marxan to provide technical advice on its application to Salmon recovery planning.
The software package assesses different sets of potential conservation areas, within a defined region, in which conservation areas are compared with user defined targets and costs and the configuration of areas that most efficiently meets the pre-defined objectives coupled with cost effectiveness are chosen as outputs.
Flow chart for running Marxan with calibration and sensitivity testing (after Ardron, J. et. al. 2010)
In the software process combinations of planning units (each unit with associated attributes) are assessed to meet objectives and cost effectiveness as above, however, a key output from this process is selection frequency output (i.e. planning units that are selected more than 50% of the time are thought of as being important for efficiently meeting biodiversity goals). From this output various scenarios can be compared with sites of importance easier to identify.
Given these key processes, Marxan provides decision support to a range of conservation planning problems, including:
Marxan analyses focuses on several inputs, these include;
From these inputs calibration must occur (adjusting the parameters of Marxan) and a sensitivity analysis which shows which input data seem to have the largest consequences in scenarios. After this initial set up the user can then explore different scenarios and outputs. These outputs are variable depending on the focus of planning; examples of outcomes include conservation-value maps, priority area maps.
Although Marxan is not integrated with GIS software, the tabular output is readily imported into a GIS through linking output tables to the spatial planning units if the ArcView format is selected in the input parameter file. Reviewing the tabular output spatially will provide further clarity to the results of the analysis and may ease communication to internal and external users.
Marxan is supported by a comprehensive website.
|State of Development||Released and updated|
|Outcome Areas||Environmental, Economic|
|Management Domains||Land, Biodiversity, Coastal|
|Intended End Users||
|Spatial Extents||Local (i.e. Catchment or District), Regional|
|Steady State or Dynamic||Unknown|
|Level of Integration||Environmental, Economic|
|Input Data Formats||Test File(s)|
|Output Data Formats||Text File(s)|
|Open/Closed Source||Open Source|
|Licence Type||Free to download - must register to download|
|Software Needed||Pluggin for QGIS avaiable|
|User Interface||No user interface|
|Ease of Use||Moderate|
|Use in Policy Process||Plan (Policy Formulation), Do (Policy Implementation), Review (Issue Identification)|
See Marxan - Documentation Page
|Keywords||Biodiversity, conservation planning, priorities|
See Marxan Website - Publications
Ardron, J. H.P. Possingham and C.J. Klein (Eds.), 2010. Marxan good practices handbook Version 2. University of Queensland, St. Lucia, Queensland, Australia, and Pacific Marine Analysis and Research Association, Vancouver, British Columbia, Canada.
Use of ' MARXAN' for selection of waters of national importance for biodiversity. Image, L.; Weatherhead, M. (2004): NIWA Client Report: CHC2004-072. 24 p.
Exploration of the use of reserve planning software to identify potential Marine Protected Areas in New Zealand's Exclusive Economic Zone. Leathwick, J., et. al. (2006): NIWA Client Report: HAM2006-064, Report for Department of Conservation
Marxan - International case studies