The most heavily militarized border on Earth, a hundred-and-fifty-mile strip of barbed wire and landmines cutting across the Korean Peninsula, has been sealed off from human contact for seventy years — and quietly become one of the most biodiverse wildlife refuges in Asia.

The most heavily militarized strip of land on Earth is also, on the available scientific evidence, one of the most ecologically important. The gap between what the DMZ was designed to accomplish in 1953 and what it has actually produced across the subsequent seven decades is, in essential respects, the central irony of contemporary Korean ecological history. The armistice negotiators who drew the line across the peninsula in July 1953 were attempting to prevent a resumption of active combat between two armies whose respective governments had agreed to stop shooting at each other but had not agreed to formally end the war. The military demarcation line was designed to separate hostile forces. The four-kilometre buffer zone was designed to make artillery-range surprise attacks difficult to execute. The landmines and the fencing and the watch towers were designed to prevent infiltration by hostile military units. None of the negotiators, on any available account of the 1953 armistice discussions, considered the ecological implications of removing all human habitation from a 1,000-square-kilometre strip of land running across the entire Korean Peninsula. The subsequent ecological consequences were, in essential respects, an accidental byproduct of the specific military architecture that the armistice had established.

According to the Natural History Museum in London’s summary of the DMZ’s ecological research literature, cumulative wildlife surveys conducted across the accessible portions of the DMZ and the adjacent Civilian Control Zone (a 5-to-10-kilometre buffer strip on the South Korean side, where limited civilian access is permitted) have documented approximately 6,168 distinct species of plants and animals — including 102 species that are officially designated as endangered on the broader Korean Peninsula species register. The 102 endangered species represent approximately 38 percent of the 267 total endangered species catalogued across the entire Korean Peninsula, meaning that the DMZ — which comprises approximately 0.5 percent of the peninsula’s total land area — hosts more than a third of the peninsula’s endangered species. This concentration is, by essentially every reasonable measure of comparative biodiversity, substantially anomalous. The DMZ is not a designated national park. It has not been managed for conservation purposes. It has, in essential respects, been protected by the specific accident of having become the most difficult-to-access piece of habitat in an otherwise rapidly-developing East Asian economic region.

What actually lives there

The specific species that have found refuge in the DMZ across the past seven decades include several that are, elsewhere in East Asia, substantially at risk of extinction. As detailed in Earth.Org’s summary of the DMZ’s ecological research conducted by the DMZ Ecology Research Institute and its director Seung-ho Kim, the DMZ’s approximately 1,000 square kilometres provide critical habitat for the red-crowned crane (Grus japonensis), of which approximately 3,000 individuals remain globally and of which a substantial fraction of the East Asian population winters in the DMZ wetlands; the white-naped crane (Grus vipio), listed as vulnerable, of which approximately 5,500 remain globally; the Siberian musk deer, the leopard cat, the Asiatic black bear, the long-tailed goral (a wild goat species), the cinereous vulture, and the black-faced spoonbill — each of which is under substantial population pressure elsewhere in the region and each of which has found in the DMZ a substantial refuge from the habitat loss, agricultural intensification, and urbanisation that have progressively reshaped the rest of the Korean Peninsula and adjacent regions across the same seven decades.

The DMZ Ecology Research Institute, which Kim founded in 2004, conducts its systematic monitoring work from within the Civilian Control Zone rather than the DMZ itself — the actual military demarcation strip remains off-limits even to accredited South Korean ecologists — and has produced substantial cumulative documentation of the DMZ’s ecosystem structure via bird counts, camera trap surveys, drone monitoring, and study of the traditional Korean rice paddies that persist in the CCZ and that function as adjacent wetland habitat for the same species that occupy the deeper DMZ areas. Kim’s substantive finding across the past two decades of research, as summarised in his interviews with Earth.Org and other outlets, is that the traditional Korean agricultural landscape — small-scale rice paddies with substantial adjacent uncultivated buffer strips, minimal chemical inputs, and long fallowing periods — has itself been essentially preserved within the CCZ across the same seven decades, and that this traditional landscape (rather than the DMZ’s dense forest cover alone) is the specific substrate that supports the highest densities of endangered species. The 21st-century industrial rice paddies that cover the substantial majority of the Korean Peninsula do not, on the available comparative data, support anywhere near the biodiversity that the CCZ’s preserved traditional rice paddies do.

What happens if peace comes

The substantive concern that the DMZ’s ecological research community has, across the past two decades, progressively raised is that the ecosystem is protected by a specific and substantially unstable set of geopolitical circumstances — the frozen 1953 armistice, the continuing military stand-off, the mutual hostility between the two Korean governments — that no reasonable observer of contemporary Korean politics considers permanent. As reported in Smithsonian Magazine’s summary of the DMZ’s ecological research and the future conservation challenges the region faces, essentially every prior political thaw between the two Korean governments — including the 2000 and 2007 inter-Korean summits under Presidents Kim Dae-jung and Roh Moo-hyun, and the more recent 2018 discussions under President Moon Jae-in — has been accompanied by substantial South Korean commercial-development proposals for the DMZ region, including proposed road and rail corridors connecting the two Koreas, proposed industrial parks in the border zone, proposed agricultural expansion into the CCZ, and proposed tourism development at the various historically-significant sites along the frontier. Each of these proposals, if implemented, would substantially fragment the existing DMZ ecosystem.

The specific conservation strategy that the DMZ Ecology Research Institute and its international partners have advocated is, as detailed in a JSTOR Daily historical analysis of the DMZ as an accidental nature preserve, the formal designation of the DMZ and the CCZ as an internationally-protected trans-boundary peace park along the model of the various European trans-boundary conservation areas that have been established along former Cold War frontiers. Proposals along these lines have been circulated at various points across the past three decades — most notably a 2005 UN-affiliated proposal supported by the American media entrepreneur Ted Turner and the DMZ Forum, a US-based non-governmental organisation founded specifically to advocate for this outcome. No formal cross-border agreement has yet been reached. The DMZ ecosystem continues to be protected by the specific accident of the frozen 1953 armistice — an arrangement that has now lasted 73 years and that, in essential respects, no one involved in its original 1953 negotiation had reason to expect would last this long. The red-crowned cranes that winter in the DMZ wetlands each year arrive, in essential respects, at the specific habitat that a specific 20th-century geopolitical failure has preserved for them. Whether the specific geopolitical failure continues, or whether it is eventually resolved into some other political arrangement that reopens the DMZ to human activity, is a substantive question that the cranes are unlikely to have any say in.