Plant communities of central Tibetan pastures in the Alpine Steppe/Kobresia pygmaea ecotone

Miehe, Georg; Miehe, Sabine; Bach, Kerstin; Nölling, J.; Hanspach, Jan; Reudenbach, Christoph; Kaiser, Knut; Wesche, Karsten; Mosbrugger, Volker; Yang, Yongping; Ma, Yaoming

doi:10.1016/j.jaridenv.2011.03.001

Cited by 84 publications

(60 citation statements)

References 42 publications

(31 reference statements)

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“…In addition, the invasion of locoweed plants, such as the genera Astragalus and Oxytropis, is responsible for alpine pasture degradation on the northwestern Tibetan Plateau (Jin et al 2011;Lu et al 2012). Sufficiently detailed information on the anthropogenic driving forces of grassland degradation cannot be extracted from available Landsat ETM+imagery but, rather, should be based on substantial field measurement indicators at a regional scale (Miehe et al 2011). Our multi-site field survey results showed that the most seriously degradation of alpine grassland was caused by the invasion of poisonous plants, primarily located in the alpine steppe zone, where GSP ranges from 250 to 350 mm ( Fig.…”

Section: Discussionmentioning

confidence: 99%

“…The effects of dominant species and the local species pool size are likely responsible for the relatively higher ratios in alpine meadow and desert-steppe. The compacted turf and roots of the dominant species of K. pygmaea in meadows can limit the invasion and dispersal processes of poisonous legume plants with longer roots (The Bureau of Land Management of Tibetan Autonomous Region and The Bureau of Animal Husbandry of Tibetan Autonomous Region 1994; Miehe et al 2011). The humid climate in the alpine meadow zone allows K. pygmaea to coexist with other small grasses, sedges, and forbs, which results in higher nonpoisonous vs. poisonous ratios of species richness, coverage, and biomass.…”

Section: Discussionmentioning

confidence: 99%

“…According to the book of BGrassland Resources in Tibetan Autonomous Region^(The Bureau of Land Management of Tibetan Autonomous Region and The Bureau of Animal Husbandry of Tibetan Autonomous Region 1994), we classified all species into two groups: non-poisonous and poisonous (including noxious) plants to large domestic herbivores (Table 1). The non-poisonous group includes grasses, sedges, and some forb species, which are highly or moderately preferred by livestock (Allen et al 2011;Wu et al 2014b), and the poisonous group mainly includes leguminous locoweeds and other poisonous forbs, such as Thalictrum alpinum, Gentiana scabra, Lamiophlomis rotate, Stellera chamaejasme, Leontopodium nanum, and Androsace tapete (Miehe et al 2011). Next, we summed the species number, coverage, and biomass of poisonous vs. non-poisonous plant groups, respectively, from the five small quadrats along the 100-m sampling transect within each site.…”

Section: Survey Designmentioning

confidence: 99%

“…Miehe et al (2011) have emphasized that the analysis of the patterns of anthropogenic disturbances cannot be performed with Landsat ETM+imagery, although it is currently available, and that the assessment or classification of grassland degradation in a given region requires more detailed field measurements. Remote sensing data, therefore, are not the most effective tool for determining whether a recovery in degraded grasslands has taken place under a specific protective management.…”

Section: Introductionmentioning

confidence: 99%

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Spatial and climatic patterns of the relative abundance of poisonous vs. non-poisonous plants across the Northern Tibetan Plateau

Yang

Zhang

et al. 2015

Environ Monit Assess

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It is the most serious challenge to promote degraded grassland recovery currently facing the developing Tibetan Autonomous Region. We conducted field surveys of 75 grazing sites between 2009 and 2012 across the Northern Tibetan Plateau and described the spatial and climatic patterns of the occurrence of poisonous plants. Our results showed lower ratios of species richness (SprRatio), coverage (CovRatio), and biomass (BioRatio) of non-poisonous vs. poisonous plants in the semi-arid alpine steppe zone, where the growing season precipitation (GSP) is between 250 and 350 mm; however, this result is in contrast to the relatively wetter meadow (GSP >350 mm) and much drier desert-steppe (GSP <250 mm) communities. Results from generalized additive models (GAMs) further confirmed that precipitation is primarily responsible for the initially decreasing and then increasing tendency of compositional ratios of non-poisonous to poisonous species. The wide confidence bands at GSP <250 mm indicated that precipitation is not an effective indicator for predicting compositional changes in desert-steppe communities. When mean annual livestock grazing pressure was incorporated into the optimal GAMs, the model performance improved: the Akaike information criterion (AIC) decreased by 1.20 for SprRatio and 3.09 for BioRatio, and the deviance explained (R 2 ) increased by 6.0 % for SprRatio and 3.6 % for BioRatio. Therefore, more detailed information on grazing disturbance (timing, frequency, and density) should be collected to disentangle the relative contribution of climate change and grazing activities to changes in community assembly and ecological functions of alpine grasslands on the Northern Tibetan Plateau.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Survey Designmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Spatial and climatic patterns of the relative abundance of poisonous vs. non-poisonous plants across the Northern Tibetan Plateau

Yang

Zhang

et al. 2015

Environ Monit Assess

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“…What has been omitted is the role of small mammals in wetland degradation, such as plateau pika (Ochotona curzoniae) endemic to the Qinghai-Tibet Plateau (Arthur et al 2007). If desiccation causes the sedge mats to dry out, the wetland will be invaded by pikas, even though they are absent in swampy wetlands (Miehe et al 2011). Moreover, the more degraded the hummocks in the wetland, the larger the pika population.…”

Section: Introductionmentioning

confidence: 99%

Degradation of wetlands on the Qinghai-Tibet Plateau: A comparison of the effectiveness of three indicators

Gao

Cheung

et al. 2013

J. Mt. Sci.

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Abstract:The Qinghai-Tibet Plateau encompasses a large quantity of wetlands, some of which have been degraded to varying severity levels. In the literature, a number of degradation indicators have been proposed to evaluate ecological health of wetlands, but their effectiveness in the plateau environment remains unknown. In this study, we assessed the effectiveness of three degradation indicators, soil moisture content at 10 cm deep, vegetative cover, and density of pika burrows. The degradation severity of wetlands in Maduo County on the Qinghai-Tibet Plateau is enumerated at four levels, intact, slight, moderate and severe. Analysis of 106 samples collected in the field demonstrates that the density of pika burrows is the least reliable indicator. By comparison, vegetative cover and underlying soil moisture content are more reliable, even though neither is a perfect indicator as the difference among adjacent levels of severity as revealed by t-test is not always statistically significant. The imperfection of vegetative cover as an indicator is due to its variation among different types of wetlands. The limitation of moisture content is attributed to its non-linear relationship with wetland degradation. Above the threshold of about 50% in moisture content wetlands are unlikely to be degraded. It is recommended that moisture be measured at the point near the surface and vegetative cover be further differentiated by species in order to improve their effectiveness.

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Evaluating the complementary relationship of evapotranspiration in the alpine steppe of the Tibetan Plateau

Zhang

Szilágyi

et al. 2015

Water Resources Research

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The complementary relationship (CR) of evapotranspiration allows the estimation of the actual evapotranspiration rate (ET a ) of the land surface using only routine meteorological data, which is of great importance in the Tibetan Plateau (TP) due to its sparse observation network. With the highest in situ automatic climate observation system in a typical semiarid alpine steppe region of the TP, the wind function of Penman was replaced by one based on the Monin-Obukhov Similarity theory for calculating the potential evapotranspiration rate (ET p ); the Priestley-Taylor coefficient, a, was estimated using observations in wet days; and the slope of the saturation vapor pressure curve was evaluated at an estimate of the wet surface temperature, provided the latter was smaller than the actual air temperature. A symmetric CR was obtained between the observed daily actual and potential evapotranspiration. Local calibration of the parameter value (in this order) is key to obtaining a symmetric CR: a, wet environment air temperature (T wea ), and wind function. Also, present symmetric CR contradicts previous research that used default parameter values for claiming an asymmetric CR in arid and semiarid regions of the TP. The effectiveness of estimating the daily ET a via symmetric CR was greatly improved when local calibrations were implemented. At the same time, an asymmetric CR was found between the observed daily ET a and pan evaporation rates (E pan ), both for D20 aboveground and E601B sunken pans. The daily ET a could also be estimated by coupling the E pan of D20 aboveground and/or E601B sunken pan through CR. The former provided good descriptors for observed ET a , while the latter still tended to overestimate it to some extent.

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Plant communities of central Tibetan pastures in the Alpine Steppe/Kobresia pygmaea ecotone

Cited by 84 publications

References 42 publications

Spatial and climatic patterns of the relative abundance of poisonous vs. non-poisonous plants across the Northern Tibetan Plateau

Spatial and climatic patterns of the relative abundance of poisonous vs. non-poisonous plants across the Northern Tibetan Plateau

Degradation of wetlands on the Qinghai-Tibet Plateau: A comparison of the effectiveness of three indicators

Evaluating the complementary relationship of evapotranspiration in the alpine steppe of the Tibetan Plateau

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