Papers by Urtnasan Mandakh
Deleted Journal, Dec 28, 2023
Deleted Journal, Dec 28, 2023
Quaternary International, 2020
Agricultural and Forest Meteorology, Mar 1, 2021
Abstract Using the normalized difference vegetation index (NDVI) and climate data, we calculated ... more Abstract Using the normalized difference vegetation index (NDVI) and climate data, we calculated the end of the growing season (EOS; unit: day-of-year (DOY)) on the Mongolian Plateau and explored the effects of the climate, the start of the growing season (SOS), and the annual peak growth (APG, unit: NDVI) of vegetation and its timing (peak growth time, PGT) on the EOS for the period of 1982-2013. The spatial distribution pattern of the EOS on the plateau presented a gradual delay from south to north in Mongolia and from southwest to northeast in Inner Mongolia, and spatially it was highly related to vegetation producty. During 1982-2013, the area-averaged EOS varied between 265.2 and 278.3, and showed a slight but non-significant advancing trend of 0.6 days decade–1, with a breaking point occurring in 1993. This insignificant advance resulted from substantial spatial heterogeneities of the trend in EOS, with advances in widespread grassland-dominated regions and delays in southwestern Inner Mongolia. Preseason air temperature (preseason means of the periods prior to the EOS date related to the EOS variation) exerted positive effects on the EOS in wet and cold areas in northern Mongolia, while preseason precipitation exerted positive effects in widespread arid and semiarid regions in central grassland regions, with different preseason lengths varying according to meteorological variables and locations. More importantly, we identified strong influences of the SOS (r=0.46, p=0.008), APG (r=0.35, p=0.05), and PGT (r=0.76, p
Plant Diversity, Dec 1, 2020
Cistanche deserticola is an important medicinal plant in Mongolia. Despite its significant role i... more Cistanche deserticola is an important medicinal plant in Mongolia. Despite its significant role in local healing systems, little traditional knowledge had been reported. The present study investigated folk names of C. deserticola and other species of the same community in Umnugobi Province, South Gobi region of Mongolia, based on ethnobotanical approaches. The high correspondence between folk names and scientific names of plant species occurring in Cistanche-associated community shows the scientific meaning of folk nomenclature and classification in Mongolia. The Mongolian and folk names of plants were formed on the basis of observations and understanding of wild plants including their morphology, phenology and traditional uses as well. Results from this study will support the conservation of C. deserticola itself, a rare and endangered plant species listed in the Monglian Red Data Book. Our documentation of folk nomenclature based on 96 plant species in the Cistanche community, as a part of traditional knowledge associated with biodiversity, will be very helpful for making strategy of plant biodiversity conservation in Mongolia.
ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2020
The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences
International Journal of Remote Sensing, 2020
ABSTRACT Maximal light-use efficiency (LUE), ɛmax, is a measure of the conversion efficiency of t... more ABSTRACT Maximal light-use efficiency (LUE), ɛmax, is a measure of the conversion efficiency of the photosynthetically active radiation absorbed by plants to net primary productivity (NPP), based on the principle that an optimal plant productive capability exists when the LUE is at its maximum. ɛmax is an important parameter for modelling regional NPP and is conventionally applied at the biome level using a constant value. In this study, we estimated type-specific ɛmax values for three dominant land cover types on the Mongolian Plateau: 0.621 g C MJ–1 (MJ is the mega Joules and 1 MJ = 106 J) for meadow steppe, 0.534 g C MJ–1 for typical steppe, and 0.520 g C MJ–1 for desert steppe. With these steppe-specific modified ɛmax values, we were able to examine changes in NPP for 2001–2015 on the plateau, as well as their likely responses to regional climate change. The use of different ɛmax values for each steppe type improved the accuracy of the Carnegie Ames Stanford Approach (CASA) Biosphere model predictions of grassland NPP by 18.8% (R2 = 0.48 to R2 = 0.57; R2 is the coefficient of determination) over the observation period. Previous studies based on a constant ɛmax (0.541 g C MJ–1) appear to underestimate ɛmax and NPP in meadow steppe, highlighting the importance of setting type-specific ɛmax values for different land cover types in the remote-sensing modelling of grassland NPP. However, more detailed maps of biome sub-classes, with species composition, would be valuable for future attempts to determine appropriate ɛmax values. The growing season (April–October) NPP on the plateau increased significantly from 2001 to 2015, with an annual increment of 4.44 g C m–2 y–1. This trend was strongly governed by the change in summer NPP across the plateau. In comparison, NPP in the spring and autumn did not influence the change in total NPP, which was likely due to their relatively small values. Summer precipitation and the related drought stress were the chief factors responsible for plateau-scale NPP changes, due to the high proportion of summer precipitation and NPP in the annual totals. This may induce important environmental features, such as dzud (a Mongolian term for a severe winter) and desertification on the plateau.
Quaternary International, 2019
Abstract The ecosystems of Mongolia are among the most sensitive to global climate change because... more Abstract The ecosystems of Mongolia are among the most sensitive to global climate change because they are located in the circumpolar boreal zone, with its arid and semiarid climate. This study used the Carnegie-Ames-Stanford Approach (CASA) model parameterized by meteorological and remote-sensing data to quantify vegetation net primary productivity (NPP) for Mongolia for 1982–2011 and further constructed a map of the relative contributions of climatic constraints to NPP. The results showed that 30-year average NPP in Mongolia varied spatially from 18.1 to 662.8 g C/m2, with an average of 228.2 g C/m2. From the map of climatic constraints on NPP, it was estimated that temperature constrains NPP variation over about 3.9% of Mongolia's land area, whereas precipitation constraints are dominant over about 77.5%. NPP in temperature-constrained regions has continuously increased from 1982 to 2011, with an annual increment of 2.18 g C/m2 (R = 0.61, p
The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2021
Agricultural and Forest Meteorology
Sustainability
Avarga Toson Lake and its surrounding area are very important for people, wildlife, and animals i... more Avarga Toson Lake and its surrounding area are very important for people, wildlife, and animals in Delgerkhaan Soum of Khentii Province in Eastern Mongolia. Some research has been conducted so as to explore the medical nature and characteristics of the lake and its surrounding area. However, the adverse effects of land use have neither been studied nor reported. The fact that the water catchment area is shrinking evidences clearly that findings of various real-time studies must be used effectively in the long-term by the local government and relevant authorities in order to take immediate remedial measures. Our study focused on land cover changes occurring as a result of human activities in the area, using a Landsat imageries and water indices approach to estimate the changes of land use and land cover. The aims of this study were to assess the land use and cover change that occurred between 1989 and 2018 and to define the impacting factors on the changes of water surface area in Av...
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Papers by Urtnasan Mandakh