land Article Long-Term Land Cover Changes in the Western Part of the Korean Demilitarized Zone Jae Hyun Kim 1,2,3 , Shinyeong Park 2, Seung Ho Kim 2 and Eun Ju Lee 3,* 1 Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 08826, Korea; [email protected] 2 DMZ Ecology Research Institute, Paju 10881, Korea; [email protected] (S.P.); [email protected] (S.H.K.) 3 School of Biological Sciences, Seoul National University, Seoul 08826, Korea * Correspondence: [email protected] Abstract: After the Korean War, human access to the Korean Demilitarized Zone (DMZ) was highly restricted. However, limited agricultural activity was allowed in the Civilian Control Zone (CCZ) surrounding the DMZ. In this study, land cover and vegetation changes in the western DMZ and CCZ from 1919 to 2017 were investigated. Coniferous forests were nearly completely destroyed during the war and were then converted to deciduous forests by ecological succession. Plains in the DMZ and CCZ areas showed different patterns of land cover changes. In the DMZ, pre-war rice paddies were gradually transformed into grasslands. These grasslands have not returned to forest, and this may be explained by wildfires set for military purposes or hydrological fluctuations in floodplains. Grasslands near the floodplains in the DMZ are highly valued for conservation as a rare land type. Most grasslands in the CCZ were converted back to rice paddies, consistent with their previous use. After the 1990s, ginseng cultivation in the CCZ increased. In addition, the landscape changes in the Korean DMZ and CCZ were affected by political circumstances between South and North Citation: Kim, J.H.; Park, S.; Kim, Korea. Our results provide baseline information for the development of ecosystem management S.H.; Lee, E.J. Long-Term Land Cover and conservation plans for the Korean DMZ and CCZ. Given the high biodiversity and ecological Changes in the Western Part of the integrity of the Korean DMZ region, transboundary governance for conservation should be designed. Korean Demilitarized Zone. Land 2021, 10, 708. https://doi.org/ Keywords: Korean DMZ; ecological succession; wildfire; temperate grassland; old map; South Korea; 10.3390/land10070708 North Korea; Korean war; transboundary ecosystem; conservation Academic Editors: Kirsten de Beurs and Le Yu 1. Introduction Received: 15 May 2021 Transboundary frontiers are areas artificially defined by international political cir- Accepted: 30 June 2021 Published: 5 July 2021 cumstances rather than ecological grounds. Many transboundary areas include high biodiversity and various landscape components [1]. Of mammal species in the Americas, Publisher’s Note: MDPI stays neutral 62% are distributed in transboundary regions [2]. The region between China and Russia is with regard to jurisdictional claims in an essential refuge for endangered Amur tigers (Panthera tigris altaica) and Amur leopards published maps and institutional affil- (Panthera pardus orientalis)[3,4]. However, since borderlines are often politically sensi- iations. tive, proper governance may not be arranged, resulting in indiscriminate poaching, and militarized frontiers may affect the ecosystem through military activities. In this context, close cooperation on the national and international levels was emphasized for habitat connectivity and ecological integrity [5–7]. The Korean Demilitarized Zone (DMZ) forms a unique transboundary ecosystem Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. across the middle of the Korean Peninsula, dividing it into South and North Korea. As This article is an open access article established by the Korean Armistice Agreement in 1953, the DMZ is 4 km wide (2 km to distributed under the terms and the south and 2 km to the north of the military demarcation line) and 248 km long at a ◦ conditions of the Creative Commons latitude of roughly 38 N. At the same time, the South Korean military established the Attribution (CC BY) license (https:// Civilian Control Zone (CCZ), a concordant area 5–10 km to the south of the DMZ. Access creativecommons.org/licenses/by/ to the DMZ has been strictly prohibited for nearly seven decades, since the end of the 4.0/). Korean War, except for certain members of the military defense force, including soldiers Land 2021, 10, 708. https://doi.org/10.3390/land10070708 https://www.mdpi.com/journal/land Land 2021, 10, 708 2 of 18 Land 2021, 10, x FOR PEER REVIEW posted in the Panmunjom Joint Security Area, and a few authorized civilians, such as the3 of 19 residents of the villages of Daeseong-dong and Kijong-dong in South and North Korea, respectively. Limited agricultural activity is permitted in the CCZ, and this limited access has resulted in exceptionally high biodiversity in the region [8]. The DMZ and CCZ have Long-term analyses of land cover could help to explore changes in ecosystems over drawn international attention due to both military tension from the Cold War, and for their extendedremarkably periods, high biodiversity and results and could unique yield ecosystem. important information about ecological param- eters The[28] landscapesand targets of for the restoration whole DMZ [29]. are classified Additionally, according the tolong-term three major tracking features of [ 9land-]. scapeThe eastern changes region is an of integral the DMZ part is best of conservation characterized planning as rugged and mountains, the maintenance and the central of biodi- versity.part is wide open plains. The western region of the DMZ and CCZ is characterized by particularlyHowever, high very biodiversity little is known due to the about heterogeneous temporal and landscapes spatial with changes rolling in topography, the landscape ofestuaries, the Korean floodplains, DMZ and and CCZ. traditional Natural agricultural succession areas over (Figures several1 decadesand2). While in these the DMZregions is worthremains exploring inaccessible, to investigate agriculture changes has been in promoted temperate in biomes the CCZ in of the South absence Korea of since human the in- terference.1970s with To the characterize establishment the of Korean the village DMZ ofTongilchon, ecosystem, justinvestigations 4.5 km south of of landscape the Military struc- turesDemarcation in the Korean Line. The DMZ inhabitants area are built essential. the village Understanding from scratch, land cultivating use and fields cover of beans, changes canginseng, clarify and factors rice. Evenaffecting though changes the agricultural in the Korean system DMZ in Korea ecosystem. has been modernized, the traditionalThis study landscape investigated in the CCZ land hasscape been changes preserved in the [10 ]Korean including DMZ the anddumbeong CCZ duringsystem the (Figure2b), which irrigates 89% of the rice paddies in the western CCZ, thus helping last 100 years. The DMZ and CCZ are in an ecological zone; however, the Korean DMZ to maintain its biodiversity [11–13]. The Korean dumbeong system provides shelter for ecosystem is exclusively off-limits to people, whereas the CCZ has allowed for some ci- wildlife even under extreme conditions [13,14]. The traditional landscape elements that vilianmake activities. up the western Thus, regionwe examined of the DMZ the CCZ and theecosystem CCZ include by biota small surveys, hills, wide and plains,the DMZ ecosystemnonconcrete on waterways, the basis of groves, satellite forests, images and streamsand supplementary flowing into brackish observations water (Figurevia the2 CCZ.). FromThe Hangang a map made and Imjingangduring the riversides, Japanese colonial with a huge period tidal to marsh satellite consisting images offrom emergent the 2010s, changesplants (e.g., in landscape reeds), Salix elementssp., mixed were forests, tracked, and broadleafand natural forests and areartificial principal factors wintering that con- tributedand stopover to these sites changes for migratory were evaluated. birds, and a vast sanctuary for invertebrates (Figure2c). Figure 1. Location of study site in the Demilitarized Zone (DMZ) and Civilian Control Zone (CCZ) of Figure 1. Location of study site in the Demilitarized Zone (DMZ) and Civilian Control Zone (CCZ) ofKorea. Korea. Red- Red- and and yellow-green yellow-green regions regions indicate indicate the study the study site, includingsite, including Paju-si Paju-si city and city Yeoncheon- and Yeonch- eon-gungun county. county. The studyThe study site is site surrounded is surrounded by large by cities large of cities North of and North South and Korea, South such Korea, as Seoul, such as Seoul,Goyang, Goyang, Paju, and Paju, Kaesong. and Kaesong. Land 2021, 10, x FOR PEER REVIEW 4 of 19 Land 2021, 10, 708 3 of 18 Figure 2. Landscape of western DMZ and CCZ in Paju. Typical topography and composition ofFigure vegetation. 2. Landscape (a) Grassland of western and forest DMZ areas inand western CCZ DMZin Paju. (photograph Typical bytopography Seung Ho Kim). and composition of (vegetation.b) Agricultural (a) landscape, Grassland including and forestdumbeong areas, in a traditionalwestern DMZ irrigation (photograph pond, in western by Seung CCZ Ho Kim). (b) Ag- (photographricultural landscape, by Jae Hyun including Kim). (c) Topographicaldumbeong, a traditional map of the westernirrigation CCZ. pond, Landscape in western mainly CCZ (photograph consistsby Jae ofHyun emergent Kim). plants (c) Topographical and Salix species inmap the riverside,of the western rice paddies, CCZ. and Landscape forests. mainly consists of emer- gent plants and Salix species