Section 1: Rangeland Ecology and Management

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https://hdl.handle.net/10217/195526

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Open Access
Changes in soil properties along grazing gradients in the mountain and forest steppe, steppe and desert steppe zones of Mongolia
(Colorado State University. Libraries, 2015-06) Baasandorj, Ya., author; Khishigbayar, J., author; Fernandez-Gimenez, M. E., author; Tsogtbaatar, J., author; Delgertsetseg, R., author; Chantsallkham, J., author; Nutag Action and Research Institute, publisher
Recent debates about the condition of Mongolia's rangelands and possible causes of rangeland change highlight the need for greater understanding of changes in grassland soil fertility and physical characteristics associated with grazing. As part of a large observational study of grazing effects on different Mongolian ecological zones and soil types (ecological sites), we studied soil characteristics along grazing gradients from winter shelters in the mountain and forest steppe, steppe and desert steppe ecozones of Mongolia. Our objective was to determine how grazing affects soil properties in winter pastures in different ecological zones and ecological sites within zones, based on grazing gradients. Our findings did not support our hypothesis that livestock grazing along a grazing gradient from winter shelters would lead to increased concentrations of nutrients (C, NO3-, P, K and humus) near the shelters. Instead, where soil chemical properties differed with distance, they were lowest close to winter shelters and higher with increasing distance. As hypothesized, we observed greater bulk densities nearer to winter shelters than farther away. Our hypothesis that grazing effects on soil properties would vary among ecological sites also was not supported. Further experimental and observational studies are needed to understand grazing effects on soil properties at different spatial scales and to examine feedbacks between livestock-induced changes in plant communities and soil quality.
Open Access
Defining the ecological site descriptions and its use as a rangeland management tool in Mongolia
(Colorado State University. Libraries, 2015-06) Densambuu, Bulgamaa, author; Ulambayar, Budbaatar, author; Battur, Ankhtsetseg, author; Sainnemekh, Sunjidmaa, author; Nyam-Ochir, Gankhuyag, author; Bestelmeier, Brandon, author; Nutag Action and Research Institute, publisher
The concept of classifying any area into ecological sites, according to that area's productivity, based on varying soil, climatic and hydrological conditions, and its capacity to endure different intensities of use and to recover from degradation, and of using this classification as a basis of rational use of natural resources is more and more recognized internationally. Since 2009, the Green Gold Project funded by the Swiss Agency for Development and Cooperation (SDC) has been exploring opportunities to develop the ecological site description (ESD) concept for Mongolian rangelands and use it as an essential tool of rangeland management. Based on soil, vegetation and geomorphological data collected from approximately 500 points representing nationwide environmental zones, we developed the ESD concept for the Mongolian context. According to this concept Mongolian rangelands are divided into some 20 zones, representing distinct ecological potentials. Based on these plot data and state and transition models a preliminary conclusion is made that over 65 percent of Mongolian rangeland has, with varying degrees, altered from its reference state, and 80 percent of this area has potential to recover through changes in rangeland management. The main objective of this research was to identify, for each environmental zone, the main factors that determine rangeland ecological potential, to develop the ESD concept and to test the possibility of using it in rangeland management. The novelty of this study, as well as its scientific and practical significance, lie in development and testing of a more detailed classification based on ecological potential within Mongolian ecological zones and geo botanical regions. This approach is significant because the classification may be used as an essential tool for rangeland use planning, implementation and monitoring, as well as for regulating rangeland use agreements.
Open Access
Satellite-based assessments on regional summer and winter conditions triggering massive livestock loss (Dzud) in Mongolia
(Colorado State University. Libraries, 2015-06) Kang, Sinkyu, author; Jang, Keunchang, author; Lkhamsuren, Bolorerdene, author; Nutag Action and Research Institute, publisher
Dzud is a term referring either to conditions when melting snow refreezes to form an icy layer covering the grass, or to unusually heavy snow falls in Eurasian arid and semi-arid regions. Under dzud condition, animals cannot obtain food under snow or ice layer, which sometimes results in a dzud disaster, i.e. massive livestock kills. It has been recognized that the dzud disaster is directly induced by the harsh winter conditions but often influenced by drought in the previous summer. In this study, a data-intensive reanalysis on regional determinants of dzud disaster was conducted for more than 300 soums (an administrative unit equivalent with county in US) in Mongolia. Various climatic, hydrological, and vegetation variables were developed from satellite remote sensing (RS) data, which includes daily mean air temperature, dew-point temperature, and evapotranspiration, monthly precipitation, and 16-day NDVI from 2003 to 2010. Annual livestock census data were collected for every soum in Mongolia. Each variable was standardized to z-score and utilized for stepwise multiple regression analysis to identify factors statistically significant for explaining soum-level livestock mortality. The regression models were successfully constructed for two-third of total soums. Considerable spatial variability in the determinants of livestock mortality were found across soums in Mongolia. As the primary determinants, summer NDVI and dryness equally explained 22% of the soum mortality, while 33% and 16% of the mortality were explained with winter temperature and precipitation, respectively. Spatial patterns were also identified with winter precipitation and temperature being primary determinants in mountain regions and northern cool and semi-arid regions, while summer NDVI and dryness were important in southern hot and arid regions. Our results indicate combined efforts of monitoring RS-based summer NDVI and dryness and forecasting winter temperature and precipitation can provide useful tools for dzud disaster early warning.
Open Access
Is overgrazing a pervasive problem across Mongolia? An examination of livestock forage demand and forage availability from 2000 to 2014
(Colorado State University. Libraries, 2015-06) Gao, W., author; Angerer, J. P., author; Fernandez-Gimenez, M. E., author; Reid, R. S., author; Nutag Action and Research Institute, publisher
Pastoral livestock production is considered a pillar of the Mongolian economy. Since the early 1990's, Mongolia has transitioned to a market economy, and livestock numbers have trended upward. Recent remote sensing studies have indicated widespread overgrazing; however, to date, no studies have examined grazing pressure on a national scale to assess the pervasiveness of overgrazing. We conducted a spatial and temporal analysis of grazing pressure by analyzing the relationship between livestock forage availability and forage demand across soums during 2000 to 2014. To estimate livestock forage demand (kg/ha/yr), we converted soum livestock densities to sheep forage units and calculated forage intake on an area basis. Forage availability was estimated using a regression relationship between herbaceous biomass and 250-m resolution MODIS NDVI (r2 = 0.70). The regression was applied to yearly maximum NDVI images to create surfaces of available forage (kg/ha/yr). Percent use (PU) of forage, which is the ratio of forage demand to forage available, was used as an indicator of grazing pressure. 50% use is generally recommended on rangelands for promoting forage regrowth and soil protection. Thirteen percent of the rangeland across Mongolia had PU that exceeded 50% during the entire time series, while 37% had 10 or more years with >50% use. Grazing pressure was higher in the central and western aimags, and lowest in the eastern aimags. Dzuds (winter disasters) in 1999-2002 and 2010 resulted in 35% and 22% reductions in livestock numbers nationwide. Grazing pressure exceeded 50% in over half of the country prior to and during dzuds due to the effect of summer drought on forage availability and high animal numbers. Grazing pressure was lowest after dzuds due to lower livestock numbers and forage response to higher rainfall. Our results indicate that heavy stocking (>50 PU) appears to be pervasive in about 32% of the country and consistent overgrazing (>=10 years with PU>=70) occurs on approximately 11% of the land area. During individual years, land areas having overgrazing are variable due to extreme climate events and linear increases in livestock numbers, regardless of forage availability, during periods between dzuds. The spatially explicit and temporal nature of these results will aid in disentangling effects of changing climate and management, and assessing the resilience of these rangeland systems in Mongolia.
Open Access
Phenology of Stipa krylovii Roshev. and Stipa tianschanica var. klemenzii Roshev., species dominating the vegetation communities of Hustai National Park
(Colorado State University. Libraries, 2015-06) Tserendulam, Ts., author; Oyuntsetseg, B., author; Nyambayar, D., author; Bayarsaikhan, U., author; Nutag Action and Research Institute, publisher
Hustai National Park (HNP), which is one of the important parts of the Mongolian Special Protection Areas network, was founded in 1992 with the purpose of reintroducing the Takhi horse (Equus ferus przewalskii). HNP vegetation phenology research was first done in 1999 and since 2003 has been conducted each year between 24th of April and 24th of September, every 10 days. The purpose of this study is to identify, with the help of dominant species, the response of vegetation growing period to climate changes and to clarify features of species' phenology changes. As a result of the research we identified and recorded general trends of dominant vegetation phenology stages and how these changes respond to environmental factors (air temperature and precipitation). Comparison of the phenology stages of the two grasses dominant in the mountain steppe and steppe communities, Stipa tianschanica var. klemenzii Roshev. and Stipa krylovii Roshev. identified that the May and June precipitation amount had a significant effect on the beginning of the species' spring growing period (p<0.027). The results show that the vegetation growing period of the species has been increasing in the mountain steppe communities.
Open Access
Towards a national mapped classification of terrestrial ecosystems in Mongolia: a pilot study in the Gobi Desert region
(Colorado State University. Libraries, 2015-06) Heiner, Michael, author; Batsaikhan, Nyamsuren, author; Galbadrakh, Davaa, author; Bayarjargal, Yunden, author; Zumberelmaa, Dash, author; Ariungerel, Dorjgotov, author; Evans, Jeffrey, author; von Werden, Henrik, author; Kiesecker, Joseph, author; Nutag Action and Research Institute, publisher
In Mongolia, partners from national and aimag governments, academia and NGOs have developed regional conservation plans that balance the government commitment to protection of natural habitats with planned development of mineral resources and related infrastructure. A key input is a mapped classification of major habitat types, or ecosystems, to represent the range of natural habitats and function as a surrogate for biodiversity. We developed a GIS model to map ecosystems across the Mongolian Gobi Desert region by comparing the distribution of plant communities and major vegetation types, taken from field surveys and national maps, with patterns of above-ground biomass, elevation, climate and topography derived from remote sensing. The resulting mapped classification is organized as a hierarchy of 1) biogeographic regions, 2) terrestrial ecosystem types based on vegetation, elevation and geomorphology, and 3) landforms. This provides a first-iteration map to support landscape-level conservation planning and a model framework that can support field surveys and future model revisions, with other applications to land use planning, research, surveys and monitoring. To facilitate that, the GIS results are publicly available either for download or to view and query in a web-based GIS available at: http://s3.amazonaws.com/DevByDesign-Web/MappingAppsVer2/Gobi/index.html.
Open Access
Distance-to-well effects on plant community based on palatability and grazing tolerance in the desert-steppe of Mongolia
(Colorado State University. Libraries, 2015-06) Narantsetseg, Amartuvshin, author; Kang, Sinkyu, author; Ko, Dongwook, author; Nutag Action and Research Institute, publisher
Wells in grasslands are usually accompanied with increased traffic by humans and livestock. The purpose of this study was to detect whether plant community structure differs in spatial arrangement with different grazing gradients in the desert steppe of Mongolia. We found poor correlation between total coverage and distance-to-well in big-shrub and shrub-limited sites but strong correlation in the small-shrub site. Dominance of palatable plants along the transect appeared in the big-shrub site but that of palatable, grazing avoider and grazing tolerant plants appeared in other two sites. The results show that these communities might respond differently to grazing pressure. Livestock trampling was limited to near the well and then grazing might be effective far from the well, because all sites showed dominance of palatable herbaceous plants. Sub-dominance of Eurotia ceratoides appeared nearest to the well and followed Caragana spp. sub-dominance. Ajania spp. sub-dominance appeared more away than E. ceratoides and Caragana spp. Dominance of palatable herbaceous plants appeared near the well, compared with that of shrubs. In all sites, palatable herbaceous plant community was replaced by grazing tolerant plant community near the well and shrubs disappeared. This indicates that succession after grazing might be faster in herbaceous plant community than shrub one.
Open Access
Land degradation assessment in Gobi-Altai Province
(Colorado State University. Libraries, 2015-06) Vova, Oyudari, author; Kappas, Martin, author; Renchin, Tsolmon, author; Degener, Jan, author; Nutag Action and Research Institute, publisher
Remote Sensing and GIS analyses were embedded to monitor interactions and relationships between land use and land cover changes in the regional ecological space of Gobi-Altai province (Western part of Mongolia). In the last 76 years, Mongolia has experienced a combination of societal and governance system changes in transitioning from the feudal system to socialism and then from the socialist system with centrally planned economy to market. Each of these resulted in changes natural resources use throughout the country. Using GIS processing of data such as climate data (precipitation, air temperature) and vegetation, socio-economic data (livestock numbers, population density) were analyzed. We focused on developing a modeling approach for monitoring land degradation using GIS and Remote Sensing tools by merging climate and quantitative socio-economic data. The Modified Soil Adjusted Vegetation Index (MSAVI) from SPOT/VEGETATION was used to define vegetation cover change for the period from 2000 to 2013. GIS conditional functions were applied for mapping and analyzing climate and socio-economic driving factors, both of which affect land degradation. Conditional functions such as MAP-Algebra from ArcGIS were developed using ground truth data and data from National Administrative Department of Statistics. Remote sensing data were useful diagnostic tools for providing gross impressions on broad-scale spatial heterogeneity, to assist in land degradation monitoring. This paper defines that study area is affected by land degradation caused by climate and socio economic impacts.

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