Бидний тухай
Багш ажилтан
There are a small number of vegetation maps of the greater Gobi region, but for Dzungarian Gobi only coarse maps are available, and these are not based on a state-of-the-art remote sensing data and sound ground-truthing. Detailed data on vegetation–environment relationships are lacking, since climate, soils and vegetation have never been comprehensively analysed. The present study is based on data collected over three different sampling periods in the Mongolian parts of the Dzungarian Basin: we sampled 208, 152 and 280 plots in 2003, 2010 and 2012-2014, using a modified Braun-Blanquet approach. All vascular plants species were recorded along with their cover, which was estimated in absolute percentages. Sample sites were deliberately chosen to represent relevant vegetation types, ranging from those of the high mountains to the oases in the lowland. A vegetation map was then prepared based on the supervised classification of remote sensing imagery. For the vegetation map, we used remote sensing imagery (Landsat mission 8, merged together from path-row WRS2 combinations 139-028, 029; 140-027, 028, 029; 141-027, 028, 029), with data being derived from remote sensing Landsat scenes using Tasseled Cap calculations for greenness, brightness, and wetness. Cloud cover for all scenes was below 10 percent. Data from the shuttle topographic radar mission was used for altitude, from which the slope of the terrain of the sample was also calculated using the spatial calculation tool “aspect” in ArcGIS. The original Landsat scenes (red, green, and blue; short-wave-infrared-1/swir1; short-wave-infrared-2/swir2; near-infrared/NIR; coastal-aerosol) were used to feed the Random Forest model. The R package raster was used to load the raster stack into the R software with the command brick. The R package RGDAL was used to import the relevé data shapefile in ArcMap GIS software. The R package geo was used to extract the information from the extract function’s locational overlaying with the raster stack for each relevé using the Landsat/Tasseled Cap/Altitude data and described derivates. We mapped four main vegetation types (forest-steppe, steppe, desert, and oasis) encompassing twenty-one plant communities, with each type showing a clear altitudinal distribution, except for the oases. The vegetation map of the Mongolian part of the Dzungarian Gobi clearly demonstrates the strong influence of relief in the area. Altitudinal gradients are reflected in a sequence of major plant community groups. The Altai ranges govern the northern part of the study region, where their steep slopes host various types of mountain steppes and related communities, including moist high-altitude pastures in the extensive upper valleys. Due to the steep altitudinal gradient (1050-2700 m), we could distinguish several types of mountain-, meadow- and desert steppes. Forest steppes are scattered between 2100-2500 m, where they cover relatively small areas on northern exposures. North-facing slopes of the upper mountain ranges are often covered by coniferous forest while more south-facing slopes, and all exposures on the lower mountain ranges, are covered by steppes locally intermingled with Juniper stands. Steppes and related units cover roughly 56% of the total study area, and the various desert communities cover about 40%. In conclusion, combining remote sensing data and ground-truthing to map the vegetation helps to accurately identify and classify different plant communities and their distribution patterns.
The Dzungarian Basin between the Altai and the Tien Shan represents the transition between Middle and Central Asia. The region hosts special plant communities that are characterized by a combination of Kazakh-Dzungarian (Dzungario-Turanian) flora elements, which extend from Middle Asia, and typical Central Asian (semi-) desert species. For the present study, we aimed to understand the plant species composition and richness in these regions by calculating the Shannon-Wiener diversity index. We sampled 644 plots using a modified Braun-Blanquet approach. Most vegetation types were rather homogenous, and we therefore selected reléve sample of 10 x 10 m2 in size. All vascular plants were recorded along with their cover, which was estimated in absolute percentage. Sample sites were deliberately chosen to represent all relevant vegetation types, ranging from the desert to the higher mountains, and including azonal vegetation like oases. Based on our results we found four different main vegetation types (forest-steppe, steppe, desert and oasis) encompassing twenty-one communities with a total of 255 vascular plant taxa belonging to 142 genera and 41 families recorded. The results indicated that Geranio pseudosibirici-Laricetum sibiricae community in the forest steppe belt at 2430 m a.sl and Halerpesto-Hordeetum brevisubulati typicum in azonal vegetation had higher indices of diversity and richness whereas, lowest in Stipo glareosae-Anabasietum brevifoliae typicum in desert steppe at 1100 m a.s.l. Changes in elevation is associated with changes in precipitation, temperature, soil type, and other factors that influence in floristic diversity in plant communities. In conclusion, plant species diversity strongly correlated with altitude in the Dzungarian Gobi and South-Western Mongolian Altai region. To further understand plant species diversity in this region, it is necessary to conduct more comprehensive studies that incorporate various environmental variables. These variables may include precipitation, temperature, soil characteristics, and grazing intensity.
The greenery of floodplain meadows in arid regions, such as Mongolia, is influenced by climate, land use, and hydrology. In this study, we analyzed the NDVI (Normalized Difference Vegetation Index) of two floodplain meadows located along the South Tamir and Tamir Rivers using LANDSAT 4-5 TM and 8 OLI_TIRS images. Our goal was to observe spatial differences, variations, and mean differences in NDVI in mid-August every six years from 1991 to 2015, and to identify the factors driving these differences. To achieve this, we conducted variance analysis to identify changes in NDVI and implemented Principal Component Analysis) to determine the influence of hydro-meteorological factors and grazing intensity. Our findings indicate a significant decrease in greenness, as measured by pixel-scale NDVI, during the late summer period. This decrease was consistently observed, except for a series of harsh winters that followed relatively dry summers, resulting in a disastrous event called dzud, which led to the death of livestock. The decrease in NDVI was amplified by lower precipitation in June, higher temperatures and wind speed in July, and increased precipitation in August, along with a higher frequency of days with convective rain. Our findings have important implications for managing grazing in Mongolia's grasslands, promoting sustainable land use, and mitigating sandstorms. The variance and average values of NDVI at the pixel level can serve as reliable markers of sustainable pasture management in areas where other vegetation measures are limited.
хураангуй хавсаргав
The annual average temperature of Mongolia has increased by 2.24°C since 1940, which is three times faster than the global average. The rising temperatures and increased potential evaporation resulted in the decreased runoff in the Mongolian part of the Selenge basin. Relatively severe runoff decrease is reported in the second interval (1996-2015) of the whole study period (1978-2015). The decrease in runoff throughout the study area was most likely caused by an increase in potential evapotranspiration (and not reduced precipitation or land use changes). Annual maximum runoff has also strongly decreased suggesting reduced flooding and consequently reduced floodplain vegetation cover which is the main pasture and hey source in the country. In order to check floodplain vegetation change, seven sites along the Orkhon and South Tamir Rivers floodplains were selected for a plant community analysis in the summer of 2016. Plant community structures were compared with data gathered in the early 70s using the same Braun-Blanquet techniques. The occurrence and cover of the hydrophytes and mesophytes decreased while the xerophytes increased. The average NDVI from 1991 to 2015 with 5-6 years intervals decreased continuously from 0.51 to 0.27. More detailed primary results will be presented.
Ereen lake is one of the lakes in the Great Lakes depression which is seen as a major freshwater basin 30 of Mongolia and contains important wetlands of Central Asia. Due to climate change and construction of Taishir hydroelectric power plant, changes in discharge of Zavkhan river occurred and therefore the adjacent lakes including Ereen lake were negatively impacted for the recent decade. This paper aims to define pollution types and levels in Ereen lake based on water quality, chemical composition of lake sludge, soil, aquatic and shore plants, inhabitants, and planktons. pH of the lake was 8.4±0.4 (n=34) and temperature was 22.1±1.5 (n=24). Dissolved oxygen was in the range of 2.9-12.4 mg/dm3 (saturation level: 34.8-139.8%). Sulphate and chloride were prevailing in anion composition and sodium-potassium were dominating in cation composition. Ammonium concentration was in the range of 1.4-3.6 mg NH4 + /L which was higher than the limit of MNS 4586:1998 (Mongolian standard for aquatic ecosystem). Lake bottom is fully covered by aquatic plants Phragmites communis and Myriophyllum sibiricum. Organic carbon content in bottom sediment samples was 0.07-1.24%, amount of potentially mobile phosphorus was -3.28-3.48 mg/100g, potassium 6 mg/100g, Ca: Mg ratio was 7-14 meq/100g and therefore nutrient availability was moderate. Ten species of rotifer (Polyarthra longiremis, Asplanchna priodonta, Brachionus quadridentatus, B. urseus, Keratella quadrata, K. cochlearis, Testudinella patina, Filinia longiseta, Lecane luna, L. cornuta, L. bula, L. rotunda, Euchlanus dilatata, Trichotria pocillum) and two species of water flea (Bosmina longirostris, Ceriodaphina quadrangula) lived in Ereen lake were obtained and which indicated lake water was organically polluted. Moreover, 22 species of 19 genus were discovered from algae samples. Results of algae identification show that eutrophication was taking place. Overall, based on the results, Ereen lake is highly polluted by heat and organic pollution and therefore subsequent changes in plant and lake inhabitants occurred as well as drop in fish population and increase in aquatic plants. These findings indicate that effective ways to remediate water pollution shall be sought urgently. Keywords: Environmental assessment of lake, water quality, baseline study of lake.
Зүүнгарын говийн ургамалжлыг ойт хээр, цөлөрхөг хээр, цөл, бүсийн бус гэсэн 4 үндсэн хэвшинжид хамаарах 21 бүлэг эвшилд ангилав.
Prasiolales нь бие даасан баг болох нь эсийн бүтцийн түвшинд, мөн молекулын анализаар тогтоогдсон. Prasiola төрөлд хамрагдах зүйлүүд нь макроскопик, бентос ногоон замгууд бөгөөд далай тэнгис, цэнгэг ус, хуурай газарт тархсан байдаг. Нийт 37 зүйл бүртгэгдсэний 14 нь цэнгэг усанд, үүний 11 нь Ази тивд тэмдэглэгджээ. Арктик, антарктик, субарктикийн хүйтэн, хөлдөлт гэсэлтийн циклтэй, эрдэс бодисын дутагдалтай нөхцөлд тархсан зүйлүүд тухайн бүс нутагтаа чухал анхдагч бүтээгчийн үүрэг гүйцэтгэдэг гэж үздэг. Parasiola fluviatilis (Sommerfelt) Areschoug ex Lagerstedt зүйл нь туузан таллусаараа цэнгэг усны бусад зүйлүүдээс ялгагддаг ба Арктикийн 70-80 градусын өргөрөг дагуу, Альпийн нуруу, Татра уул, Бритиш Колумбын Балд уул, Андын нурууны Боливын хэсэгт жижиг гол горхинуудад бүртгэгдэж ирсэн ба сүүлийн жилүүдэд Памир, Тяньшаны салбар уулст мөстлөгийн гаралтай жижиг гол горхиноос олдсон. Бид Parasiola fluviatilis-ийг Монгол Алтайн нурууны салбар уул Сутай хайрхны мөнх цасны хайлалтаас гаралтай жижиг горхиноос цуглуулж, таллусыг субстратад бэхлэх үүрэгтэй салслаг хөхлөг, түүнд бэхлэгдэх шураг хэлбэрийн шилбэ, апланоспор зэрэг өвөрмөц бүтцүүдийг илрүүллээ. Эдгээр шинж тэмдэг нь орчны ялгаатай нөхцөл дэх морфологийн уян хатан шинж үү, эсвэл тухайн зүйлийг шинэ зүйл гэж үзэхэд хүргэх үү гэдгийг цаашдын судалгаагаар тодруулах шаардлагатай.
Ýóòðîôèêàöè íü íóóð áîëîí áóñàä óñàí ñàí äàõü òýæýýëèéí áîäèñ(nutrient)- ûí õóðèìòëàëààñ ¿¿äýëòýé óðãàìëûí ºñºëòèéã äýìæèõ ¿éë ÿâö þì. Çàìãèéí ºñºëò, õºãæèëä òýæýýëèéí áîäèñ (ÿëàíãóÿà ôîñôîð, àçîò) íýí ÷óõàë ó÷ðààñ çàìàã íü áèîëîãèéí èíäèêàòîð ç¿éë áîëäîã. Ýíý ñóäàëãàà íü Òýðõèéí öàãààí íóóðûí öàõèóðò çàìãèéí á¿ëãýìäëèéí á¿òöèéã òîäîðõîéëîõ, ç¿éë¿¿äèéí ýêîëîãèéí øààðäëàãàä ¿íäýñëýí íóóðûí àìüäðàõ îð÷íûã ¿íýëýõ çîðèëãîòîé. Òýðõèéí öàãààí íóóðûí ýðýã äàãóóõ 13 öýãýýñ äýýæ öóãëóóëæ, áàéíãûí áýëäìýë áýëòãýí, ìèêðîñêîïûí õ1000 ºñãºëò äýýð õîëáîãäîõ á¿òýýë¿¿äèéã àøèãëàí 37 òºðëèéí 176 ç¿éëèéã èëð¿¿ëæ, õàðüöàíãóé àðâèéã òîãòîîñîí. Á¿ëãýìäýëä ø¿ëòëýã îð÷èíä îðãàíèê ãàðàëòàé àçîòûí äóíä çýðãèéí êîíöåíòðàöèéã òýñâýðëýäýã, ìºí õ¿÷èëòºðºã÷èéí 75%-èéí õàíãàìæ øààðääàã Achnanthes minutussima var minutissima, Coccoines placentula var placentula, Gomphonema minutum, Staurosirella pinnata çýðýã ç¿éë¿¿ä äàâàìãàéëæ áàéíà. Óñíû ÷àíàð äóíäæààñ äîîãóóð, òðîôèê òºëºâ áàéäàë íü ýóòðîôèê áóþó òýæýýëèéí áîäèñûí àãóóëàìæ ºíäºð õýìýýí ¿íýëýãäýæ áàéíà.
This paper confi rms the presence of Prasiola fl uviatilis from the Mongolian Altai and documents some previously undescribed morphological features, such as a screwshaped stipes anchored in the mucilage pads strongly adherent to the substrate; and vegetative, asexual and sexual reproduction structures. Besides these characteristic, the sporadic occurrence of green patches of algal colonies on the immobile stones along the glacial stream but not in the main channel togetherwith cyanobacterial fi laments could indicate its desiccation, freeze-thaw cycle, fl ooding and nutrient limitation adaptations and capacity to recover after the stresses.
Water quality monitoring is one of the main problems for Mongolia since people and livestock directly use surface and shallow well water for drinking. Water quality could be evaluated by bacterial abundance and diversity changes. There are lots of studies on microbial abundance and diversity along rivers. However, most of them are conducted in developed countries. Therefore, it is needed to investigate the bacterial abundance and diversity changes in our rivers. We will introduce how did we detect the bacterial abundance and diversity changes along the Kharaa River. In terms of diversity analysis, we did not find significant changes, especially at the broader taxonomic categories such as phylum, subphylum, class, order, and family. But we found significant shifts in the OTU (Operational Taxonomic Unit) abundance, especially by detecting the most trendy (with increasing and decreasing abundance along the river) OTUs along the Kharaa River. In the next step, we will analyze what environmental factors are shaping these shifts.
The preserved diatom flora in a 14C dated (0-6230 yBP), 343 cm long core sequence from Lake Telmen, Mongolia, was investigated to determine the nature of the lake-ecosystem and watershed response to Late Holocene climate change. Modern Lake Telmen is a slightly saline (presently 4 g L-1) closedbasin lake located along a N-S and E-W aridity ecotone in north-central Mongolia, making it sensitive to climate-driven changes in effective moisture balance. Diatoms were not preserved regularly in two areas of the Lake Telmen sediment record (5380-41 50 yBP and 1050-425 yBP) possibly due to high carbonate preservation; however, diatom preservation between these areas was good to excellent. Diatom-based paleosalinity reconstruction using species-specific salinity optima from the Northern Great Plains of North America and community analysis suggests the following climate-lake response model during the Late Holocene. From 6230 to 5520 radiocarbon years ago, warm-dry climate resulted in a small salty (20 g L-1) lake in the Telmen basin that was dominated by high salinity indicator species (e.g. Cyclotella caspia, Navicellapusilla, Brachysira aponina). From 3 860 to 1200 radiocarbon yBP, Lake Telmen recorded a period of a modulating climate that resulted in regular fluctuations in paleosalinity from 2 to 4 g L-1 in conjunction with lake level changes. Dominance in the diatom flora fluctuated between the freshwater planktonic form Cyclotella bodanica var. affinis and the salinity-tolerant benthic taxon Anomoeoneis sphaerophora f. costata during this period characterized by generally more humid climatic periods interspersed with dry-as-present conditions. The most modern samples (0-250 yBP) preserve floristic assemblages similar to those found between 3860 to 1200 radiocarbon yBP and indicate that as recently as 250 years ago Lake Telmen had lower salinity values than modern day.
The Dzungarian Gobi (DzG), one of 16 phytogeographical regions in the country, is located in the southwestern part of Khovd province in western Mongolia. It comprises some of Mongolia’s largest reserves, namely the Great Gobi B Strictly Protected Area and the National Park Bulgan gol-Ikh Ongog. We conducted a comprehensive survey of the area’s floristic diversity between 2009 and 2019 by collecting vascular plants from different vegetation types in various seasons. In addition, we critically checked relevant published literature and material from the herbaria ALTB, GLM, GWF, HAL, KHU, LE, MW, NS, OSBU, UBA, and UBU to determine the occurrence of vascular plant species in the DzG region. Based on our collection data, a comprehensive checklist of DzG’s flora was compiled, representing 913 vascular plant taxa (including 34 subspecies and one variety) belonging to 329 genera and 70 families. Twenty-one taxa were newly found in the DzG region. We also investigated the conservation status of all species noted, and 19 endemic plants and 96 threatened species, including six critically endangered, 26 endangered, 57 vulnerable, and seven near threatened plants were recognized in this region. Eight rare species were newly assessed according to regional conservation status based on GeoCat and IUCN. The richest plant families found were Asteraceae (153 species), Fabaceae (77 species), Amaranthaceae (69 species), and Poaceae (68 species). Several uncertain endemic and non-endemic plants remain still discussion, such as Papaver baitagense and Rosa baitagensis; thus, further studies are needed on their taxonomic and conservation status. For each taxon, we provide its distribution in the region, elevation range, voucher number, and additional references. Finally, we analyzed species hotspots of DzG, based on three different plant species richness criteria: i. all recorded species, ii. endemic species, and iii. threatened species using our georeferenced records. The most diverse hotspot area in DzG is the Baitag Bogd Mountain area, which comprises the highest species number of all three richness criteria.
Sea buckthorn (Hippophae rhamnoides L.) provides multiple products that are beneficial to human health. In addition, the plant is also used to combat desertification. In contrast to the vast ecological, agronomic and nutritional literature on this species, little is known about its economic and marketing aspects, particularly in Central Asia. We therefore analysed the private and social competitiveness of sea buckthorn farming in 21 households of Bulgan county of Khovd province in Mongolia. The results show that half of the interviewed sea buckthorn farmers are privately competitive. We found that social competitiveness exceeded private competitiveness because while private output prices are supported by government policies, which increases private profits, input prices are also supported, which reduces the competitiveness. The net effect of supports to input and output prices taxes producers and reduces private competitiveness. In our study area the most competitive households had larger land sizes, fenced wild sea buckthorn areas, and were more experienced than others. The competitiveness of sea buckthorn farming increased from 2012 to 2013, which may be due to a government support programme. The most serious challenge facing sea buckthorn production is lack of finance, which is mirrored by the fact that investment costs contribute more than one third to total costs.
The Selenge basin contributes approximately 50% of the total inflow into Lake Baikal and is thus of high significance for the regional hydrological regime. Our study was conducted in the upper reaches of the basin, where the Selenge river and its tributaries flow through the Mongolian forest-steppe. Monthly and maximum runoff, precipitation, and air temperature data from 12 gauging stations collected between 1978 and 2015 were analyzed to characterize the hydrological regime response to climate change. Concomitant with rising temperatures and increased potential evaporation, river runoff in the Mongolian part of the Selenge basin has decreased from the first interval (1978–1995) of our study period compared with the consecutive interval from 1996 to 2015. The decrease in runoff throughout the study area was most likely caused by an increase in potential evapotranspiration (and not reduced precipitation or land use changes) for both summer rainfall- and snowmelt-dominated rivers. Annual maximum runoff has also strongly decreased suggesting that reduced flooding is a contemporary threat for Mongolia’s riverine ecosystems, probably causing the replacement of wetland and mesic habitats.
In this paper the taxonomic composition of phytoplankton, diatoms and microcrustaceans (cladocerans and copepods) in lakes of the Great Lakes Depression (Mongolia) is examined. The inventories were based on samples collected in seven lakes and in one small reservoir between 2005 and 2009. Four lakes and the reservoir are of fresh water, (110 - 300 µS/cm of water conductivity) and the three remaining lakes are endorheic and with more mineralized water (5,270 – 9,550 µS/cm of water conductivity). In the phytoplankton 136 taxa were identifi ed, where 29 species and 10 genera are the new records for Mongolia. In case of Diatoms 122 species were identifi ed and 48 of them are the new records for Mongolia. Thirty-nine species of cladocerans and 9 species of copepods were identifi ed, 13 species of cladocerans and one copepod are new for Mongolian fauna. In general, the taxa belonging to the diff erent analyzed groups (pytoplankton, diatoms and microcrustaceans) are known throughout the Palaearctic region. Most taxa of all the analyzed taxonomic groups take place in the lakes with low mineralization, while lakes with more mineralized waters had signifi cantly lower species richness.
An improved knowledge of long-term climatic variations over the Altai-Dzungarian region will increase our understanding of the current climate and help to predict the effects of global warming on future water availability in this region. We sampled 77 Larix sibirica Ledeb. trees at upper and lower treelines in the southern Mongolian Altai mountains and reconstructed temperature and precipitation for longer periods than previous studies from this area. We reconstructed mean June–July air temperatures for the period 1402–2012 and June–December precipitation for the period 1569–2012 based on tree ring width chronologies. The temperature and precipitation reconstructions explain 39.7 and 41.3% of the respective station observation variance during the common periods. The precipitation reconstruction shows alternating wet and dry conditions during the Little Ice Age (1580–1874) followed by more stable conditions until a late 20th century wetting. The temperature reconstruction attributes the warmest period to the 20th century, which follows cooler periods related to volcanic and low solar activities during the Little Ice Age. Long-term climatic variation and change over the Altai-Dzungarian region is inferred from the analysis of the combined temperature and precipitation reconstructions for the common period 1580–2012. Accordingly, this region has become warmer since 1875 as the number of warm/moist and warm/dry years increased by 2 and 14%, respectively, while the number of cool/moist and cool/dry years both decreased by 8% compared to the Little Ice Age. Our findings also reveal a late 20th century cool and wet period, which has also been observed across other mountainous areas of China and Nepal. This period was most probably caused by volcanic-induced cooling and coincided positive phases of the Arctic Oscillation and North Atlantic Oscillation promoting an intensified subtropical westerly jet and a positive summer rainfall anomaly over the Altai-Dzungarian region.
In 2015, the Mongolian Bird Taxonomy and rarity Committee (MBTRC) listed 170 species as rare in Mongolia. A joint team of the Mongolian Ornithological Society, National University of Mongolia and Mönkhkhairkhan Protected Area Administration conducted field surveys on the distribution, number, occurrence and migration of birds in the Bulgan river valley of Khovd province between 13-20 May, 2015 and in the Yolyn Am and Khongoryn Els of Ömnögobi province between 20-28 June and 5 to 25 August, 2015. The aim of these surveys was to determine the avian species composition in these areas, to document data on vagrant and rare species, and to update the status of the species in these areas. The team listed 273 bird species in the Bulgan River valley. This include 11 rare species in Mongolia (Ferruginous duck, White-headed duck, Asian dowitcher, Pallas’s fish eagle, Eurasian oriole, Red turtle dove, Black-throated accentor, Common nightingale, Eurasian linnet, Grey-crowned goldfinch, European greenfinch). Five of these species (Black-throated accentor, Common nightingale, Grey-crowned goldfinch or Grey-headed goldfinch, Eurasian linnet, and Turkestan tit) are the first photographic records for Mongolia.
The Valley of the Great Lakes (VOGL) in western Mongolia is dominated by two main (Uvs, Khyargas) and many minor closed basin lake systems. In 2004 and 2005, we sampled diatom communities from the surficial sediment of 64 lakes in the western Mongolian provinces of Uvs, Khovd, Zavkhan, and Bayan-Ulgii. Lakes ranged in water chemistry from fresh to hypersaline, oligotrophic to hypertrophic, and from low elevation VOGL lakes to high elevation lakes in the Altai Mountains. Over 300 diatom species were identified in the sediment samples including a diverse flora limited to saline lakes, many widespread taxa, many new reports for the Mongolian diatom flora, and several new and possibly endemic species. We also review recent diatom literature from Mongolia including floristic surveys, paleo-ecology, and water quality studies.
This survey report presents basin morphology, water quality, and sedimentological data from twenty-one Mongolian lakes, and is meant to be used as a resource for future geological and biological investigations. The lakes are organized in three separate groups based on geographic location, and the survey results from each lake are described in detail. A short discussion of local and regional factors infl uencing solute concentrations and pH levels of the lakes’ waters is presented. The lakes present at latitudes lower than N 50°00’ (i.e. central and north/central lakes) are distributed across an area of approximately 150,000 km2 and vary considerably with respect to their water quality characteristics. Regional precipitation patterns as a function of geographic location and/or catchment specifi c processes are indentifi ed as the driving mechanisms for variations in solute concentrations and pH levels in these lakes. The surveyed lakes present at latitudes higher than N50°00’ (i.e. northern lakes) are distributed across a smaller area (approximately 180 km2 ) and have relatively little variation in water quality characteristics. These lakes straddle the local taiga/alpine tundra transition zone, and elevation (i.e. valley placement) is identifi ed as the driving mechanism for inter-lake variations in solute concentrations and pH levels.
