Landscape, at a given spatial scale, fundamentally represents a heterogeneous composition of biophysical, social, and cultural objects developed by natural means and/or human interventions on the earth’s surface [1
]. These objects in a landscape scale can be seen as various landforms, vegetation patches, water bodies, settlement areas, roads, etc., and are referred to as land covers or features [3
]. The features in spatial configuration make up the landscape structure [1
], giving an identity to the landscape that can possess a distinctive appearance, in contrast to the surroundings [6
]. Nevertheless, the natural pressure, including storm, flood, fire, earthquake, and/or anthropogenic land use and management, are all drivers that modify the landscape and make it unstable [6
Modification of the landscape by humans has been rather significant across the globe, and, in consequence, it yields an impact on the landscape structure as well as on the interaction between landscape features [8
]. However, research on the ecological aspects of landscape is very limited in tropical Asia [9
]. The current study is a preliminary effort to develop deeper knowledge of ecosystem services and management through safeguarding the cultural heritage at the Dry Zone of Myanmar.
The Bagan Cultural Heritage Site (BCHS) is home to 3822 medieval-aged Buddhist monuments—stupas (solid-type pyramidal structures), temples, and monasteries [10
]. The entire stretch of the BCHS is 22,809.85 ha, composed of eight monumental zones (MZ), together with other components, and it expands over the eastern and western banks of the Ayeyarwady River [14
]. The MZ is defined by the presence of monuments within a designated area and, of the eight zones, the MZ-1 accounts for more than 2000 monuments [15
The presence of more than 50% of the region’s total monuments makes the MZ-1 a unique landscape. The monuments were built during the 11–13th centuries [18
] by early settlers in the Bagan area, and such activities are regarded as attempts to transform the terrain into a cultural landscape [19
]. In the present era, there are seven residential areas in the MZ-1, and agricultural lands managed by the residents in the environs of the monuments endow the zone with a living landscape. This study’s focus, therefore, centres on how residents in those areas manage the landscape with respect to the hundreds of monuments as safeguarding measures for tangible and intangible cultural heritage. Agricultural land management, in explicit postulation, is a trigger of impacts on the environmental setting of the heritage site; therefore, management-related data to date are a prerequisite for long-term analytical studies.
Within the Dry Zone of Myanmar, people’s livelihoods are primarily dependent on agriculture, with 57% of the land altered through cultivation [20
]. Nevertheless, global climate change has also affected agricultural production for people in the dry zone, due to irregular rainfall [21
]. Moreover, experiencing life in the Dry Zone, the MZ-1 settlers have experienced the ripple effects of the adverse climate on their agricultural activities. If crop production declines, the land used for cultivation by local farmers is likely to be minimized. Reducing cultivated land implies shrinking crop cover in one word, and expanding weedy cover and/ or shrub on the agricultural land in other words. The current conditions of agricultural land use might have created some distinctive characteristics regarding landscape features at the MZ-1. The speculation, therefore, was a matter of the analytical study on contemporary landscape structure, based on two specific objectives: (1) To identify landscape features as land cover on the basis of land use, and (2) to evaluate the interrelationship of features at the MZ-1 in terms of spatial coverage.
The status of features, as well as land use impacts, was first assessed by satellite image analysis, and, second, the interdependence among the features was evaluated by multivariate analysis. The study shed light on vegetated and non-vegetated features as a primary structure of the landscape of the MZ-1, reflecting four major components in coexistence—“unmanaged vegetated cover”, “anthropogenic artefacts”, “agricultural land”, and “reservoir”. The results of the current study stress the important role of site management, explicitly, agricultural land, due to massive expansion of unmanaged vegetated cover in landscape scale. Regarding well-rooted conservation and preservation measures for the monuments and the site, the study suggests the vegetation in the zone to be under management for strengthening integrity of the cultural landscape.
Contemporary landscape structures of the MZ-1 comprise six land covers, referred to as “features” in Table 1
. The features reflect human-induced landscapes of the zone, where lands used for agriculture, buildings, roads, and reservoirs coexist with unmanaged vegetated lands.
The uniqueness of the MZ-1 is the presence of ten-century-old monuments, clustered across the zone [11
], which are viewed in coexistence with other human-induced landscape features. In the vicinity of the monuments are the farmlands, where the local settlers cultivate peanuts, sesame, mung beans, pigeon peas, and sorghum for their major livelihood. The crops sown at the study site are similar to those grown in other parts of the Dry Zone of Myanmar [20
], and they are the leading agricultural species [21
]. Crop fields characterize land use activity by the local farmers during the farming season from May to December each year. The proportion of the land with crop coverage in this study, however, reflects 7.5%, which is apparently half of the exposed (ploughed) land surface area. The results suggest that agricultural land is incompletely covered with crops, while some areas remain uncultivated, even during the cropping season. Field surveys conducted by the authors agree with the data regarding uncultivated acreage at the study site. This is likely due to various socio-economic factors of local land users. It is questionable whether the presence of the uncultivated fields downgrades the landscape of the MZ-1; nevertheless, it is an issue for future research and analysis. A tourism sector development project implemented in very recent years promotes the unique landscape of Bagan for the coexistence of its agricultural lands with its monuments [34
]. Interestingly, the crop fields are independent of the monuments and other existing features, and this reveals that the presence of the cultivated fields in particular has little or no impact on the monuments in terms of land use.
The exposed land that is recognized as a part of the agricultural area, on the other hand, is in a positive relationship with the shrub-prone patches. The land appears to have been left uncropped after ploughing until the end of September, which is the later part of the monsoon season (mid-May to October). It seems that rainfall at the study site did not provide sufficient moisture for crop growing as the crops are exclusively rain-fed, thereby expanding the exposed land surface to about 15% of the MZ-1 (Table 1
). Receiving erratic rainfall during the crop season has driven the failure of crop yield in an area of the Dry Zone [22
]. This might have led to a socio-economic impact on the livelihood of local farmers. In the case of leaving the land exposed, the incidence of shrubs appears to conquer such land surfaces by means of natural succession. The land, in consequence, would have transformed into shrub-prone area, and the data of the current study suggest that the more the exposed land, the larger the expansion of the shrub-prone patch.
The second largest area of shrub-prone patch at the study site implies that the massive proportion of cultivatable lands has been recently left with no more crop cover after ploughing or previous sowing. Under favourable conditions, those lands are subject to the regeneration of shrubs, which gradually invade the entire exposed land surface. Within a short duration of exposure after crop activity, the degree of shrub incidence on the land is found to be high [35
]. If continuous cultivation is practiced in each growing season, ploughing the earth’s crust is a means of destroying shrub propagules and would reduce the shrub-invaded lands. The shrub-invaded patches may have functioned as storehouses for disseminated propagules of woody plant species in the surrounding areas. This argument is supported by reports on increasing plant species and density, including woody plants, due to the presence of shrubs in a particular habitat [36
]. The shrub-prone patch supports growth of woody plants that, unless encountered by further human intervention, would transform into semi-natural woody vegetation. The results of the current study also suggest that the shrub-prone land is a trigger for the incremental spread of the semi-natural woody vegetation. The data agreed with the observations of Wang et al. (2016) [38
] that a forest regenerates by natural means of grass and shrub covers via land use change after agricultural activity.
The stretch of the semi-natural woody vegetation at the MZ-1 is astonishingly large, covering 37% of the zone (Table 1
). Since it is a time-course factor, massive expansion of such vegetation in the contemporary landscape shows that little or no management has been applied to the shrub-prone patches developed from the exposed lands in recent years. Local xeromorphic woody plants such as Acacia catechu
, Acacia leucophloea
, Borassus flabellifer
, and Zizyphus jujuba
are common to the study site, whereas Prosopis juliflora
has become an invasive species widely across the Dry Zone of Myanmar [39
]. The P. juliflora
is a robust, semi-arid tree species that has an outstanding characteristic of invasion into natural and/or human-induced landscapes [41
]. However, no data of its location-specific invasion to the landscape of the MZ-1 are available for the current study. A remarkable result of the relationship between the semi-natural woody vegetation and the monument, instead, reveals that the area’s expansion of woody plant species has been extending to the environs of the monuments. If the plants grow close to the monuments, the root extension could penetrate the structures, inducing flaws and cracks. Under severe conditions, a collapse of the monuments might lead to the loss of the historical symbols.
The existence of the built-up features and the water is also independent of others at the MZ-1. The built-up features are mainly seen as settlement areas, paved roads, and monumental compounds occupying 13% of the zone, while the waters as the reservoirs are the smallest occupancy, at less than 1%. The data suggest that the MZ-1 is not yet very urbanized, although there are anthropogenic features integrating into the landscape.
This study was unable to interpret the monuments, both in the 30-m and the 15-m resolution images of Landsat 8, probably due to insufficient image quality to access the monuments. Field-recorded GPS points of monument locations and/or those accessed in a 2-m resolution Google Earth map (CNES/ Airbus, 2018), however, accounted 2348 monuments scattered within the MZ-1. This revealed that ground-truth data are of the utmost importance to validate the monuments in this study. Of the geolocated monument points plotted on the pan-sharpened image, they superimposed the built-up features and the semi-natural woody vegetation. Crosscheck in Google Earth clarified that some monument points in the range of 1–6 were in the enclosures designated as monumental compounds, where platforms and developed structures stretched in proximity to the monuments. The enclosures spotted in and outside the residential areas, and some intermingled with the semi-natural vegetation. The locations of the monument enclosures were also checked in the inventory maps of Pichard (1992–1995) [12
]. Validations supported interpreting the monumental compounds as the built-up feature.
The close relationship existing between the shrub-prone patches and the semi-natural woody vegetation accounts for the prominence of “unmanaged vegetated cover” at the study site. The argument illustrates on the one hand the tendency for land to transform into a natural state; on the other hand, it points to the amendment of the current landscape as a safeguarding measure for protection of the historical setting. Reflecting poor site management apparently, the expansion of unmanaged vegetation within the MZ-1 would become an interference for access to the monuments. The threat may also downgrade the attractiveness and magnificence of the cultural landscape. Stands of tall woody plants are supposedly an obstruction to the view and to the monuments. Erect above the small-sized monuments, tree-type vegetation would hinder the structures and seriously damage the monuments by root penetration. Propagules disseminated by such vegetation to the surrounding area are an important source of regeneration over the landscape. Cultivation activities on the farmland are creditable to suppress the sprouts and seeds of those plants, mainly in the rainy season. Successive controls in every onset of rain by agricultural land management of local farmers are highly appreciated as a matter of timely site management. Since the MZ-1 is of a historically developed landscape, anthropogenic modifications over time have remade the landscape as part of the cultural identity. In short, coexisting with the built-up features, referred to as “anthropogenic artefacts”, “agricultural land”, and “reservoir”, proper management of semi-natural vegetation, would improve the value of the landscape. Through enhancing living landscape, local communities, pilgrims and visitors, and, collectively, the global society are expected to receive ecosystem services directly or indirectly from the heritage site in the Dry Zone of Myanmar.
The contemporary landscape of the MZ-1 is predominantly structured with (1) vegetated land covers or features of crop field, semi-natural woody vegetation, and shrub-prone patches; and (2) non-vegetated built-up features, exposed land, and water. The land use for the crop field quantifies a small proportion, compared to the 4–6 times larger coverage of the other two vegetated features. The built-up feature and the exposed land also occupy the amount of area similar to that of the crop field, whilst the water makes up the smallest fraction. In land-use aspects, crop cultivation on agricultural land is found to have depreciated, while the exposed land surface remains as large as the crop-covered area. Low occupancy of the built-up structures reflects the fact that the zone is not highly populated, perhaps still in the (traditional) rural landscape. The contrasting areas of features yield to the evaluation of their coexisting relationships in the MZ-1.
Independence of the existing crop field indicates that agricultural area has no impact on other features, particularly on monuments at the MZ-1. However, the semi-natural woody vegetation develops in the environs of the monuments and seems to be a threat to them. The growth of this vegetation is triggered by the occurrence of the shrub-prone patch; the latter, in turn, is driven by the expansion of the exposed lands. In this regard, agricultural land use and management and the coverage of semi-natural vegetation relative to the monument areas in such landscapes are significant matters for further investigation. The remarkable prominence of “unmanaged vegetated cover” coexisting with “anthropogenic artefacts”, “agricultural land”, and “reservoirs” draws attention to timely amendments of the human-induced landscape as safeguarding measures for the historical settings in Bagan. Provided that no accessibility to the locations of the monuments was available, the assessment of the relationship between the monuments and the other features will not be given any account in the current study.
The study deduces management-related features of the contemporary landscape, stressing priority to locally best-fit strategies for long-term management of tangible and intangible cultural heritage, through broadly covered national law. The study’s results emphasize the role of agricultural land that primarily matters for safeguarding the heritage site. Coverage of cultivated crops over the farmlands in corresponding growing seasons will be a breakthrough of strengthening the living landscape in the dry zone ecosystem. Suggesting governmental policy implication and supports, the study urges the intrinsic involvement of local stakeholders in the holistic management of the entities and the site.