11 research outputs found
Effects of Grazing on vegetation in the Gobi desert region of Mongolia
Mongolia is a massive, semi-arid country in Central Asia with a huge territory of 1,500,000 km2, with rangeland making up around 75% of the country\u27s territory. These rangelands have supported herders and grazing animals for millennia. The transition from nomadic to stationary livestock husbandry in Mongolia’s rangeland has resulted in major changes in vegetation communities due to increased livestock numbers. The primary objective of this study is to examine the impacts of grazing on the vegetation of rangelands in the desert steppe ecosystem. The purpose of this study is to examine the impacts of livestock grazing by measuring vegetation standing crop biomass, vegetation cover, and species\u27 richness. The study was carried out in Khanbogd soum (district), Umnugovi aimag, the southern province of Mongolia. To assess the grazing impact, we sampled fourteen winter camps of herders who are members of the four herder groups, who were located at 1000 m and 2000 m from each. In total, we sampled 28 plots in two consecutive years. Our results indicate that aboveground biomass, cover, and species\u27 richness did not differ with increasing distance from winter camps. Similar grazing pressures were shown at 1,000 and 2,000 meters away from the winter camps as well
Climate change reduces extent of temperate drylands and intensifies drought in deep soils
Drylands cover 40% of the global terrestrial surface and provide important
ecosystem services. While drylands as a whole are expected to increase in
extent and aridity in coming decades, temperature and precipitation forecasts
vary by latitude and geographic region suggesting different trajectories for
tropical, subtropical, and temperate drylands. Uncertainty in the future of
tropical and subtropical drylands is well constrained, whereas soil moisture
and ecological droughts, which drive vegetation productivity and composition,
remain poorly understood in temperate drylands. Here we show that, over the
twenty first century, temperate drylands may contract by a third, primarily
converting to subtropical drylands, and that deep soil layers could be
increasingly dry during the growing season. These changes imply major shifts
in vegetation and ecosystem service delivery. Our results illustrate the
importance of appropriate drought measures and, as a global study that focuses
on temperate drylands, highlight a distinct fate for these highly populated
areas
Widening global variability in grassland biomass since the 1980s
Global change is associated with variable shifts in the annual production of aboveground plant biomass, suggesting localized sensitivities with unclear causal origins. Combining remotely sensed normalized difference vegetation index data since the 1980s with contemporary field data from 84 grasslands on 6 continents, we show a widening divergence in site-level biomass ranging from +51% to −34% globally. Biomass generally increased in warmer, wetter and species-rich sites with longer growing seasons and declined in species-poor arid areas. Phenological changes were widespread, revealing substantive transitions in grassland seasonal cycling. Grazing, nitrogen deposition and plant invasion were prevalent in some regions but did not predict overall trends. Grasslands are undergoing sizable changes in production, with implications for food security, biodiversity and carbon storage especially in arid regions where declines are accelerating
The effect of copper mining on vegetation disturbances in and out of Oyu Tolgoi mining site
Since 2005, the mining sector has been a vital part of Mongolia's economy. This sector is one of Mongolia's most important sources of revenue. Primary outputs of Mongolia's mining industry are copper, gold, and coal. On the other hand, mining has a negative impact on the environment causing soil erosion, noise pollution, water pollution, and biodiversity loss. The Oyu Tolgoi copper mine is located in a semi-arid zone in the Mongolian Gobi. The impact of mining was investigated by sampling eight plots both in and out of this giant mining site. Vegetative cover, species richness, biomass, and basal gap of perennial plants were compared within and outside the perimeter of the Oyu Tolgoi mining site. The mining sites have a harmful impact on the environment. According to our findings vegetation cover, species richness, biomass, and perennial plant gaps were not different between the paired plots outside and inside of the mining site. Mining activities had little effect on vegetation, according to the findings
Main Habitats and Floristic Diversity in the Tarvagatai Nuruu National Park – General View
This research was conducted as part of an overall assessment of biological diversity of the Tarvagatai
Nuruu National Park in summer 2007. One objective of our research was to assess main habitats,
fl
oristic diversity and speci
fi
c
fl
oristic conservation value of the area within the Mongolian network
of protected areas. A total of 335 vascular plant species were recorded in the study area, also the main
habitats and their species richness were characterized. The observed
fl
oristic characteristics, reasons for
the observed relatively high species richness in the area as well as the combination of the
fl
ora from
Tarvagatai mountain range on basis of eco-geographical elements and the conservation value of this area
are discussed in this paper
Quantifying the Spatial Extent of Roads and Their Effects on the Vegetation in Mongolia’s Gobi Desert
Thirty years ago, Mongolia’s Gobi Desert was intact, roadless and had low traffic, and it was a refuge for many endangered and rare species. A large mining boom and significant livestock grazing are currently putting pressure on the desert. Mining products were transported by trucks on dirt (gravel) roads between 2000 and 2012. Emphasizing its importance in the Mongolian economy, a paved road was constructed in 2012 along the dirt road. Unfortunately, vegetation along the paved road was removed without restoration. In the desert, locals continue to use, create and extend dirt roads. The impact of these roads on the vegetation has yet to be studied. We estimated the spatial extent of the dirt-road corridors in three time intervals (the years 2010, 2015 and 2020) and evaluated the vegetation along both paved and dirt roads at three distances (100, 500, and 900 m) from the road. Within ten years, the length of paved roads and soil dirt roads nearly doubled, although the majority of them were developed and created between 2015 and 2020. A single track makes up around 42 percent of the soil road, whereas the remaining 58 percent are roads consisting of three to four tracks with an average width of 26.5 m. The vegetation along the paved road was lower in terms of species richness, canopy cover, and the basal gap between perennial plants and biomass, compared to the soil road. Although the effects of soil roads on the vegetation along the roads is less negative than the effects of the paved road, the corridors formed along the soil roads span a non-negligible area of pastureland in the region. The vegetation along the already-constructed paved road in the desert should be artificially reclaimed with the aim of expediting natural revegetation. Moreover, a “new legislation” is required to prevent continued degradation due to the ongoing creation and extension of soil road corridors by local populations in the desert
Appendix A. Figures showing relative abundance distributions for species contributing to community-level analysis, soil and air temperatures for open-top chamber (OTC) and control plots on the upper and lower slope in 2009, and peak flowering time for species included in community-level analyses.
Figures showing relative abundance distributions for species contributing to community-level analysis, soil and air temperatures for open-top chamber (OTC) and control plots on the upper and lower slope in 2009, and peak flowering time for species included in community-level analyses
Data from: Functional group, biomass, and climate change effects on ecological drought in semiarid grasslands
Water relations in plant communities are influenced both by contrasting functional groups (grasses, shrubs) and by climate change via complex effects on interception, uptake and transpiration. We modelled the effects of functional group replacement and biomass increase, both of which can be outcomes of invasion and vegetation management, and climate change on ecological drought (soil water potential below which photosynthesis stops) in 340 semiarid grassland sites over 30-year periods. Relative to control vegetation (climate and site-determined mixes of functional groups), the frequency and duration of drought were increased by shrubs and decreased by annual grasses. The rankings of shrubs, control vegetation, and annual grasses in terms of drought effects were generally consistent in current and future climates, suggesting that current differences among functional groups on drought effects predict future differences. Climate change accompanied by experimentally-increased biomass (i.e. the effects of invasions that increase community biomass, or management that increases productivity through fertilization or respite from grazing) increased drought frequency and duration, and advanced drought onset. Our results suggest that the replacement of perennial temperate semiarid grasslands by shrubs, or increased biomass, can increase ecological drought both in current and future climates
Global temperate drylands climate change vulnerability
Drylands cover 40% of the global terrestrial surface and provide important ecosystem services. While drylands as a whole are expected to increase in distribution and aridity in coming decades, temperature and precipitation forecasts vary by latitude and geographic region suggesting different trajectories for tropical, subtropical, and temperate drylands. Uncertainty in the future of tropical and subtropical drylands is well constrained, whereas soil moisture and ecological droughts, which drive vegetation productivity and composition, remain poorly understood in temperate drylands. Here we show that, over the 21st century, temperate drylands may contract by a third, primarily converting to subtropical drylands, and that deep soil layers will be increasingly dry during the growing season. These changes imply major shifts in vegetation and ecosystem service delivery. Our results illustrate the importance of appropriate drought measures and, as the first global study to focus on temperate drylands, highlight a distinct fate for these highly-populated areas. The data are outputs from the SOILWAT ecohydrological model, which was applied in a grid over 6 temperate drylands across the globe (South America, Southern Africa, Eastern Asia, Western and Central Asia, Western Mediterranean basin, and North America. Simulations were conducted for two time periods: 1980-2010 and 2069-2099