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The Grasslands of Inner Mongolia: A Special Feature

July 2009
Rangeland Ecology & Management 62(4):303-304

DOI:10.2111/09-002.1

Authors:

Xing-Guo Han

Chinese Academy of Sciences

M. Keith Owens

Oklahoma State University

X. Ben Wu

Texas A&M University

Jianguo Wu

Arizona State University

Show all 5 authorsHide

Grasslands of northern China are of great ecological, economic, and cultural importance (Kang et al. 2007). These immense grasslands cover 400 million ha or 40% of the land area of China and stretch 4 500 km northeast–southwest (lat 28 u N to lat 51 u N). They extend from the northeastern plains adjacent to Mongolia to the southern Tibetan Plateau and consist of four major types: meadow steppes, typical steppes, desert steppes, and alpine steppes (Sun 2005; Kang et al. 2007). Inner Mongolia has 87 million ha of natural grassland, which is a significant constituent of the Eurasian Steppe—the largest contiguous biome in the world (Li 1962, 1979; Wu and Loucks 1992). From east to west, meadow steppe, typical steppe, and desert steppe zones occur in response to the decreasing moisture gradient.

The types and spatial extents of grassland ecosystems and other vegetation types in Inner Mongolia, China.

…

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The Grasslands of Inner Mongolia: A Special Feature

Xingguo Han,

Keith Owens,

X. Ben Wu,

1,3

Jianguo Wu,

1,4

and Jianhui Huang

Authors are

Professors, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, People’s Republic of China;

Professor and Head, Department

of Natural Resource Ecology and Management, Oklahoma State University, Stillwater, OK 74078, USA;

Professor, Department of Ecosystem Science

and Management, Texas A&M University, College Station, TX 77843, USA; and

Professor, School of Life Sciences and Global Institute of Sustainability,

Arizona State University, Tempe, AZ 85287, USA.

Grasslands of northern China are of great ecological, economic,

and cultural importance (Kang et al. 2007). These immense

grasslands cover 400 million ha or 40% of the land area of China

and stretch 4 500 km northeast–southwest (lat 28uNtolat

51uN). They extend from the northeastern plains adjacent to

Mongolia to the southern Tibetan Plateau and consist of four

major types: meadow steppes, typical steppes, desert steppes, and

alpine steppes (Sun 2005; Kang et al. 2007). Inner Mongolia has

87 million ha of natural grassland, which is a significant

constituent of the Eurasian Steppe—the largest contiguous biome

in the world (Li 1962, 1979; Wu and Loucks 1992). From east to

west, meadow steppe, typical steppe, and desert steppe zones

occur in response to the decreasing moisture gradient (Fig. 1).

Substantial land use change and ecosystem degradation have

occurred within the Inner Mongolia grassland over the last half

century, which has resulted in significant ecological and

socioeconomic consequences at both local and regional scales

(National Research Council 1992; Tong et al. 2004; Jiang et al.

2006). The primary ecological problem is land degradation,

which is attributable mainly to overgrazing and land conver-

sion. Land degradation has led to the deterioration of

biodiversity and ecosystem function and services as well as a

myriad of environmental and economic problems such as sand

storms and poverty. Overgrazing, as the primary cause of land

degradation, is a result of improper land management practices

and the exceedingly large population density of domesticated

animals (Jiang et al. 2006).

Substantial research has been conducted on the ecology and

management of China’s grasslands (see a recent review by Kang et

al. 2007), including early vegetation surveys by Russian, Japanese,

and Western explorers (pre-1950s); systematic natural resource

inventory through surveys of vegetation, soils, and topography by

the Chinese Academy of Sciences and collaborating institutions

(1950–1975); long-term monitoring and studies of grassland

ecosystem structure and function through the establishment of

field research stations (1976–1995); and most recently (since

1996) the expansion of experimental studies of community

dynamics, ecosystem function, and global change that are

increasingly multiscale and multidisciplinary in nature (National

Research Council 1992; Kang et al. 2007). These studies should

be of great interest to the readers of Rangeland Ecology &

Management in other parts of the world. A large number of these

studies, however, have been published in Chinese and are not

readily accessible to non-Chinese readers, although the number of

papers published in English journals has increased rapidly in

recent years (e.g., Niu et al. 2003; Yamano et al. 2003; Zhang et

al. 2003; Bai et al. 2004; Chen at al. 2004; Kang et al. 2004; Wang

et al. 2006; Zhou et al. 2006). The expanse and diversity of these

grasslands make them significant ecologically and their manage-

ment has large regional and global implications. A great deal more

research is needed for better understanding the dynamics of the

social–ecological systems in these areas and for improving policy

and management measures to achieve grassland sustainability.

We present this special feature with a small sample of the

grassland research in China and hope that it will promote greater

awareness of these vast rangelands. This has grown out of the

efforts of a symposium at a Society for Range Management

(SRM) annual meeting on ‘‘Grasslands of Northern China:

Ecology and Contemporary Issues’’ cosponsored by the SRM

International Affairs Committee and the Institute of Botany of

the Chinese Academy of Sciences (CAS), with partial support

from Dow AgroSciences. Through both the symposium and this

special feature, we want to encourage additional research

collaboration on the ecology and management of the grasslands

of China. The special feature includes six studies conducted in the

grassland regions of Inner Mongolia, China. Most of these

studies were conducted at field research stations operated by the

Institute of Botany of the CAS.

Four of the studies focused on the ecology of the typical

steppe grassland and the effects of rangeland management

practices. Ping Liu et al. (this issue) investigated decomposition

rates and nutrient dynamics of leaf, stem, and root litter of five

common plant species in the typical steppe and explored the

potential impact of grazing-induced changes in plant species

composition on ecosystem function at the Duolun Restoration

Ecology Research Station. Baoyin and Li (this issue) reported

the results of a long-term (24-yr) monitoring study, at the

Grassland Ecosystem Research Station of CAS, on the

effectiveness of rangeland management practices (shallow

plowing and harrowing) on the restoration of degraded Leymus

chinensis grassland. Huajie Liu et al. (this issue) evaluated the

effects of grazing intensity on the cover, species composition,

and nitrogen fixation of biological soil crusts in a 16-yr grazing

study also conducted at the Grassland Ecosystem Research

Station. The study of Liang et al. (this issue) focused on grazing

impacts on the vegetation dynamics along a grazing gradient

radiating from residential areas around the Keshiketeng

Banner, Chifeng Prefecture, in northeastern Inner Mongolia.

The other two studies were conducted at the Ordos Sandland

Ecological Research Station of CAS, focusing on fragile

grassland ecosystems and the desertification process. Zhu et

al. (this issue) investigated the responses of seed germination

and seedling growth to sand burial of two dominant perennial

Correspondence: Dr X. Ben Wu, Ecosystem Science and Management, Texas A&M

University, College Station, TX 77843, USA. Email: xbw@tamu.edu

Rangeland Ecol Manage 62:303–304

July 2009

RANGELAND ECOLOGY & MANAGEMENT 62(4) July 2009 303

grasses in Mu-Us sandland. Li et al. (this issue) explored the

environmental constraints on the productivity of the sandland

plant communities dominated by Artemisia ordosica on sand

dunes of different mobility. Both contributed to the knowledge

base essential for combating desertification and for ecological

restoration of the sandland ecosystems.

We hope that the papers in this special feature will be

followed by many quality publications in Rangeland Ecology

& Management addressing the grasslands of China. It is also

our hope to encourage greater international collaborations of

rangeland and social scientists leading to better understanding

and sustainability of these and other rangeland ecosystems

throughout the world.

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vegetation in Xilinhot, Inner Mongolia, China. International Journal of Remote

Sensing 24:3171–3178.

ZHANG, Y., Z. ZHANG,AND J. LIU . 2003. Burrowing rodents as ecosystem engineers:

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alpine meadow ecosystems on the Tibetan Plateau. Mammal Review

33:284–294.

ZHOU, Z., O. J. SUN,J.HUANG,Y.GAO,AND X. HAN. 2006. Land use affects the

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Figure 1. The types and spatial extents of grassland ecosystems and

other vegetation types in Inner Mongolia, China.

304 Rangeland Ecology & Management

Faith, reciprocity, and balance

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Biodiversity is declining at an unprecedented rate. Many grassland species have been lost and are now of conservation concern. Identifying efficient biodiversity indicators is a key pillar of the global conservation strategy. Mongolian Lark (Melanocorypha mongolica) is a charismatic bird species abound in Mongolian steppes, and recent studies demonstrated that this species share similar habitat requirements and likely co-occur with other grassland birds. We tested the hypothesis that Mongolian Lark would make a suitable indicator for different aspects of avian biodiversity. We made a large-scale bird survey in Inner Mongolia, and classified point counts into three groups based on different taxonomic, functional, and phylogenetic biodiversity measures. We identified species indicators of each group using the indicator value (IndVal) analysis, and examined the bird compositional difference among groups. Linear models were used for studying the patterns of occurrence of Mongolian Lark in relation to various biodiversity measures. Mongolian Lark showed the highest indicator value in comparison with other potential species indicators. Bird species richness is significantly higher at sites with Mongolian Lark, and its occurrence was negatively correlated with species abundance, functional richness, Rao's quadratic entropy and phylogenetic diversity. Mongolian Lark is therefore a suitable indicator species for avian biodiversity in Mongolian steppes. It is highly distinctive in flight and usually seen singly. The widespread distribution and charismatic appearance make it easy to monitor and adequate for citizen science, and may provide useful information on the paradigm of surrogacy in conservation ecology.

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Interannual fluctuations in precipitation shape the trajectory of ecosystem respiration along a grazing exclusion chronosequence in a typical steppe in Inner Mongolia

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Purpose Changes in precipitation amount and land use are expected to greatly impact soil respiration (Rs) of grasslands, but little is known about whether they can interactively impact Rs and how plant and soil microbial communities regulate the Rs response. Methods We investigated the impacts of altered precipitation amount (–50%, ambient and + 50%) and land use (fencing, mowing and grazing) on autotrophic (Ra), heterotrophic (Rh) and total Rs as well as their abiotic and biotic drivers with a field experiment in the Inner Mongolian grassland. Results Precipitation positively impacted respirations and 50% changes in precipitation leads to more substantial changes in abiotic and biotic drivers, and thus respirations, than land use. We identified the interactive effects and found that, over the 3-year experiment, a 50% decrease in precipitation caused a 31.9% decrease in Rs under fencing, but a 38.4% and a 37.2% decrease under grazing and mowing, respectively. Conclusions Our results indicate that taking the more intensive land use into consideration can precisely predict grassland carbon cycling in responding to future precipitation changes. In addition, chronically shifted plant and soil microbial communities under changing precipitation and land use may regulate the long-term responses of carbon cycling in grasslands.

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Purpose: Changes in precipitation amount and land use are expected to greatly impact soil respiration (Rs) of grassland ecosystems. However, little is known about whether they can interactively impact Rs and how plant and soil microbial communities regulate the response of Rs. Methods: Here, we investigated the impacts of altered precipitation amount (–50%, ambient and +50%) and land-use regime (fencing, mowing and grazing) on Rs with a field experiment in the Inner Mongolian grassland. Results: We found that altered precipitation amount impacted Rs and its components across the 3-year study period, while land-use regime alone or its interaction with precipitation amount impacted them in certain years. In addition, changed soil microclimate, especially soil moisture, under altered precipitation amount and land-use regime can impact the components of Rs either directly or indirectly via influencing plant and soil microbial communities. Conclusions: Integrating changing precipitation amount and land-use regime within experiment can produce more accurate insights into grassland Rs, and chronically shifted plant and soil microbial communities under these changes may result in distinct long-term impacts on Rs.

Xilingele (The Xilingol Grassland)

Chapter

Full-text available

Jan 1992

Land use affects the relationship between species diversity and productivity at the local scale in a semi-arid steppe Ecosystem

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The accelerating extinction rate of plant species and its effect on ecosystem functioning is a hotly debated topic in ecological research. Most research projects concerning the relationship between species diversity and productivity have been conducted in artificial plant communities, with only a few in natural ecosystems. In this study we examined the relationship between species diversity and above‐ground net primary productivity (ANPP) over two consecutive growth seasons (2004 and 2005) in a semi‐arid steppe ecosystem of northern China, that were subjected to different land uses. Land use affected the relationship between species diversity and ANPP in this semi‐arid steppe ecosystem. Exclusion of grazing without or with biomass removal by mowing increased ANPP, species richness and species diversity compared with free grazing; the effect was reflected mainly as enhanced importance of the perennial forbs functional group in terms of their relative contributions to ANPP, plant cover and plant abundance. Many mechanisms regulate the relationship between species diversity and productivity. Differential effects of anthropogenic activities on biodiversity and ecosystem functioning greatly complicate the analysis of such relationships. On grazing‐exclusion sites the relationship between ANPP and species richness can be best described as an exponential growth function ( R ² = 0·99, P < 0·001, n = 24); whereas on the free‐grazing site the relationship takes the form of exponential decay ( R ² = 0·96, P < 0·001, n = 24). Our study concludes that the mode and severity of disturbance are important factors for interpreting the relationship between species diversity and productivity in semi‐arid steppe ecosystems.

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Full-text available

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Article

Full-text available

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The two dominant species, Leymus chinensis and Stipa grandis have different distribution area in the Xilin River Basin: relatively wet and fertile for L. chinensis and dryer and leaner for S. grandis. Different photosynthetic physiology traits and resource use efficiency might contribute to the distribution pattern of two species in heterogeneous habitats. In this study, the plant nitrogen (N) content, C/N ratio, values and photosynthetic characteristics of L. chinensis and S. grandis were measured at five different N addition rates. We found that N addition resulted in significant increase in N concentration of plant tissues and decrease in C/N ratio of the two species; L. chinensis had higher N concentration and lower C/N ratio than S. grandis. Increasing N addition rates enhanced the maximum photosynthetic rate (Am) of L. chinensis, whereas Am of S. grandis responded only to low N supply rates. Nitrogen addition led to a decrease in the maximum apparent quantum yield (Φm) but had little effect on the light compensation point (LCP) and the light saturation point (LSP) of the two species. Varying N addition rates did not alter the gas exchange characteristics including net photosynthetic rate (A), transpiration rate (E), stomatal conductance (gs), and intercellular CO2 concentration (Ci). A and gs of L. chinensis were consistently and considerably higher than those of S. grandis with and without N addition. Although there were no significant effects of N supply on the instantaneous water-use efficiency (WUEi), the values of L. chinensis were significantly higher with increased N addition rates. A closely positive correlation was found between and WUEi in the two species. Our results suggested that contrasting physiological strategies were employed to adapt to drought by two plant species, i.e., high A and E for L. chinensis versus low A and E for S. grandis; L. chinensis achieved higher WUE at the expense of decreasing nitrogen use efficiency (NUE), whereas, S. grandis could simultaneously maintain relative higher WUE and NUE. This interspecific difference in the trade-off of plasticity between NUE and WUE may partially explain the regional distribution of those two species in relation to the moisture and nutrient availability.

Ecosystem stability and compensatory effects in the Inner Mongolia grassland

Article

Full-text available

Oct 2004
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Numerous studies have suggested that biodiversity reduces variability in ecosystem productivity through compensatory effects; that is, a species increases in its abundance in response to the reduction of another in a fluctuating environment. But this view has been challenged on several grounds. Because most studies have been based on artificially constructed grasslands with short duration, long-term studies of natural ecosystems are needed. On the basis of a 24-year study of the Inner Mongolia grassland, here we present three key findings. First, that January-July precipitation is the primary climatic factor causing fluctuations in community biomass production; second, that ecosystem stability (conversely related to variability in community biomass production) increases progressively along the hierarchy of organizational levels (that is, from species to functional group to whole community); and finally, that the community-level stability seems to arise from compensatory interactions among major components at both species and functional group levels. From a hierarchical perspective, our results corroborate some previous findings of compensatory effects. Undisturbed mature steppe ecosystems seem to culminate with high biodiversity, productivity and ecosystem stability concurrently. Because these relationships are correlational, further studies are necessary to verify the causation among these factors. Our study provides new insights for better management and restoration of the rapidly degrading Inner Mongolia grassland.

The analysis of large-scale gene expression to the phase changes of the migratory locust

Article

Full-text available

Dec 2004

The migratory locust is one of the most notorious agricultural pests that undergo a well known reversible, density-dependent phase transition from the solitary to the gregarious. To demonstrate the underlying molecular mechanisms of the phase change, we generated 76,012 ESTs from the whole body and dissected organs in the two phases. Comparing 12,161 unigene clusters, we identified 532 genes as phase-related (P < 0.01). Comprehensive assessment of the phase-related expression revealed that, whereas most of the genes in various categories from hind legs and the midgut are down-regulated in the gregarious phase, several gene classes in the head are impressively up-regulated, including those with peptidase, receptor, and oxygen-binding activities and those related to development, cell growth, and responses to external stimuli. Among them, a superfamily of proteins, the JHPH super-family, which includes juvenile hormone-binding protein, hexamerins, prophenoloxidase, and hemocyanins, were highly expressed in the heads of the gregarious hoppers and hind legs of the solitary hoppers. Quantitative PCR experiments confirmed in part the EST results. These differentially regulated genes have strong functional implications that numerous molecular activities are involved in phase plasticity. This study provides ample molecular markers and genomic information on hemimetabolous insects and insights into the genetic and molecular mechanisms of phase changes in locusts. • solitary phase • gregarious phase • EST • unigene

Hyperspectral identification of grassland vegetation in Xilinhot, Inner Mongolia, China

Article

Aug 2003

Derivative spectroscopy of hyperspectral reflectance data of grassland vegetation was used to extract the wavelength peaks of different grass species of Xilinhot, Inner Mongolia, China. Caragana microphylla, which is characteristic of dry areas, was successfully detected among the four dominant grass species found in the typical Xilinhot grassland, using fourth-derivative peaks around 670 nm and 720 nm. A radiative transfer simulation showed that the identification scheme was not distorted by the atmosphere during airborne remote sensing. This suggests that high-order derivative spectroscopy of hyperspectral reflectance data from grassland vegetation can be an effective tool for advanced mapping and for the monitoring of grasslands.

Burrowing rodents as ecosystem engineers: The ecology and management of plateau zokors Myospalax fontanierii in alpine meadow ecosystems on the Tibetan Plateau

Article

Sep 2003

1. Plateau zokors, Myospalax fontanierii, are the only subterranean herbivores on the Tibetan plateau of China. Although the population biology of plateau zokors has been studied for many years, the interactions between zokors and plants, especially for the maintenance and structure of ecological communities, have been poorly recognized. In the past, plateau zokors have been traditionally viewed as pests, competitors with cattle, and agents of soil erosion, thus eradication programmes have been carried out by local governments and farmers. Zokors are also widely and heavily exploited for their use in traditional Chinese medicine. 2. Like other fossorial animals, such as pocket gophers Geomys spp. and prairie dogs Cynomys spp. in similar ecosystems, zokors may act to increase local environmental heterogeneity at the landscape level, aid in the formation, aeration and mixing of soil, and enhance infiltration of water into the soil thus curtailing erosion. The changes that zokors cause in the physical environment, vegetation and soil clearly affect the herbivore food web. Equally, plateau zokors also provide a significant food source for many avian and mammalian predators on the plateau. Zokor control leading to depletion of prey and secondary poisoning may therefore present problems for populations of numerous other animals. 3. We highlight the important role plateau zokors play in the Tibetan plateau ecosystem. Plateau zokors should be managed in concert with other comprehensive rangeland treatments to ensure the ecological equilibrium and preservation of native biodiversity, as well as the long-term sustainable use of pastureland by domestic livestock.

A landscape-scale assessment of steppe degradation in the Xilin River Basin, Inner Mongolia, China

Article

Oct 2004

Steppe degradation is a major ecological and economic problem in the Inner Mongolia steppe region, China because it reduces grassland productivity and leads to desertification. The objective of this study was to assess the spatial extent and severity of steppe degradation in the Xilin River Basin, Inner Mongolia using a landscape-scale approach. Our approach combined information from field survey records, existing vegetation maps, and remote sensing data to determine the different degrees of degradation for diverse steppe communities at the local scale and their spatial pattern at the landscape scale. We also developed a steppe degradation index (SDI) that integrates the information on the spatial extent and severity of steppe degradation. Our results showed that the total area of degraded steppe in this region increased from 7191.3 km2 in 1985 to 7689.3 km2 (72% of the total basin) in 1999. We used SDI to quantify the degree of degradation and its changes in space and time. The SDI maps revealed that large-scale patterns of steppe degradation were related to landform types. For both 1985 and 1999, the four landforms exhibited increasing degrees of degradation in the following order: low mountains > lava tablelands > hills > high plains. Several seriously degraded regions in the Xilin River Basin were identified. This study demonstrates the effectiveness of combining remote sensing data and synoptic ecological indices in assessing ecosystem degradation, and provides useful information for improving grassland management practices and restoring the degraded steppe vegetation in the Xilin River Basin, Inner Mongolia.