Marxan
Encyclopedia
MARXAN is software designed to aid systematic reserve design on conservation planning. With the use of stochastic optimisation routines (Simulated Annealing
) it generates spatial reserve systems that achieve particular biodiversity representation goals with reasonable optimality.
Computationally, MARXAN provides solutions to a conservation version of the 0-1 knapsack problem
, where the objects of interest are potential reserve sites with given biological attributes. The simulated annealing algorithm attempts to minimise the total cost of the reserve system, while achieving a set of conservation goals (typically that a certain percentage of each geographical/biological feature is represented by the reserve system).
in 2000, and was supervised and funded by Hugh Possingham
, who currently holds a Federation Fellowship
at the University of Queensland
. It was an extension of the existing SPEXAN program.
, in Queensland
, Australia
, the largest marine protected area in the world . It has been used for many other marine reserve planning applications, including:
MARXAN has been used extensively by The Nature Conservancy
, and is a major part of the systematic planning tools being used in the Global Marine Initiative. The World Wildlife Fund used MARXAN to define a Global set of Marine Protected Areas, the Roadmap to Recovery, which they used to petition the UN about the creation of open ocean marine reserve networks.
The software has also been used in terrestrial applications, such as:
Simulated annealing
Simulated annealing is a generic probabilistic metaheuristic for the global optimization problem of locating a good approximation to the global optimum of a given function in a large search space. It is often used when the search space is discrete...
) it generates spatial reserve systems that achieve particular biodiversity representation goals with reasonable optimality.
Computationally, MARXAN provides solutions to a conservation version of the 0-1 knapsack problem
Knapsack problem
The knapsack problem or rucksack problem is a problem in combinatorial optimization: Given a set of items, each with a weight and a value, determine the count of each item to include in a collection so that the total weight is less than or equal to a given limit and the total value is as large as...
, where the objects of interest are potential reserve sites with given biological attributes. The simulated annealing algorithm attempts to minimise the total cost of the reserve system, while achieving a set of conservation goals (typically that a certain percentage of each geographical/biological feature is represented by the reserve system).
History
MARXAN is a portmanteau acronym, fusing MARine, and SPEXAN, itself an acronym for SPatially EXplicit ANnealing. It was a product of Ian R. Ball's PhD thesis, while he was a student at the University of AdelaideUniversity of Adelaide
The University of Adelaide is a public university located in Adelaide, South Australia. Established in 1874, it is the third oldest university in Australia...
in 2000, and was supervised and funded by Hugh Possingham
Hugh Possingham
Hugh Phillip Possingham, FAA , is an ARC Federation Fellow in the Department of Mathematics, and the School of Integrative Biology at the University of Queensland...
, who currently holds a Federation Fellowship
Federation Fellowship
Federation Fellowships are Australian professorial research fellowships that were instigated by the Australian Government as part of their Backing Australia's Ability initiative. They were initially designed to compete with prestigious overseas grants in an attempt to lure back high profile...
at the University of Queensland
University of Queensland
The University of Queensland, also known as UQ, is a public university located in state of Queensland, Australia. Founded in 1909, it is the oldest and largest university in Queensland and the fifth oldest in the nation...
. It was an extension of the existing SPEXAN program.
Application
MARXAN is the most widely used systematic reserve planning software in the world , and has been used to create the marine reserve network on the Great Barrier ReefGreat Barrier Reef
The Great Barrier Reef is the world'slargest reef system composed of over 2,900 individual reefs and 900 islands stretching for over 2,600 kilometres over an area of approximately...
, in Queensland
Queensland
Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...
, Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, the largest marine protected area in the world . It has been used for many other marine reserve planning applications, including:
- Channel Islands of CaliforniaChannel Islands of CaliforniaThe Channel Islands of California are a chain of eight islands located in the Pacific Ocean off the coast of Southern California along the Santa Barbara Channel in the United States of America...
- Gulf of MexicoGulf of MexicoThe Gulf of Mexico is a partially landlocked ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. In...
http://www.intecmar.usb.ve/CoMLCaribbean/Summaries/summary_TNC.htm - Galapagos IslandsGalápagos IslandsThe Galápagos Islands are an archipelago of volcanic islands distributed around the equator in the Pacific Ocean, west of continental Ecuador, of which they are a part.The Galápagos Islands and its surrounding waters form an Ecuadorian province, a national park, and a...
- South AustraliaSouth AustraliaSouth Australia is a state of Australia in the southern central part of the country. It covers some of the most arid parts of the continent; with a total land area of , it is the fourth largest of Australia's six states and two territories.South Australia shares borders with all of the mainland...
http://www.marine.csiro.au/nddq/ndd_search.Browse_Citation?txtSession=184 - British ColumbiaBritish ColumbiaBritish Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
- ConnecticutConnecticutConnecticut is a state in the New England region of the northeastern United States. It is bordered by Rhode Island to the east, Massachusetts to the north, and the state of New York to the west and the south .Connecticut is named for the Connecticut River, the major U.S. river that approximately...
/New YorkNew YorkNew York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east... - Central Coast of CaliforniaCentral Coast of CaliforniaThe Central Coast is an area of California, United States, roughly spanning the area between the Monterey Bay and Point Conception. It extends through Santa Cruz County, San Benito County, Monterey County, San Luis Obispo County, and Santa Barbara County...
- Baltic SeaBaltic SeaThe Baltic Sea is a brackish mediterranean sea located in Northern Europe, from 53°N to 66°N latitude and from 20°E to 26°E longitude. It is bounded by the Scandinavian Peninsula, the mainland of Europe, and the Danish islands. It drains into the Kattegat by way of the Øresund, the Great Belt and...
MARXAN has been used extensively by The Nature Conservancy
The Nature Conservancy
The Nature Conservancy is a US charitable environmental organization that works to preserve the plants, animals, and natural communities that represent the diversity of life on Earth by protecting the lands and waters they need to survive....
, and is a major part of the systematic planning tools being used in the Global Marine Initiative. The World Wildlife Fund used MARXAN to define a Global set of Marine Protected Areas, the Roadmap to Recovery, which they used to petition the UN about the creation of open ocean marine reserve networks.
The software has also been used in terrestrial applications, such as:
- The North American Wildlands ProjectWildlands ProjectThe Wildlands Network was created in 1991 to stem the tide of species extinctions that was being recorded across North America...
. - Selecting priority areas for Global Mammal Assemblages.
- Planning the conservation of ecosystem servicesEcosystem servicesHumankind benefits from a multitude of resources and processes that are supplied by natural ecosystems. Collectively, these benefits are known as ecosystem services and include products like clean drinking water and processes such as the decomposition of wastes...
. - The Great Sand Hills of Saskatchewan Regional Environmental Study http://www.environment.gov.sk.ca/Default.aspx?DN=8663b7a6-5eb3-4e0b-b59b-0a0c81fdbc9f
Shortcomings
One shortcoming of MARXAN is its inability to deal with issues of demographic inter-connectedness. In marine systems, the presence of a biological feature does not guarantee the persistence of that feature in the absence of the surrounding ecosystem. This is a concept generally known as "connectivity". MARXAN considers that including into a reserve system a site that contains a particular feature will ensure the persistence of that feature, even though surrounding sites may not be included in the reserve system, and may therefore be ecologically compromised. MARXAN does employ a "boundary length modifier", which attempts to minimise the boundary length to area ratio, thus increasing the continuity of the reserve systems. This ad-hoc alteration may go some way to addressing the problem .External links
- MARXAN Homepage, information and download
- A thorough rundown of the software specifications by the National Commission on Science for Sustainable Forestry
- This article in Marine Protected Area News discusses the pros and cons of the software in the context of MPA planning.