| 4 | The Representation of Soil Moisture−Atmosphere Feedbacks across the Tibetan Plateau in CMIP6显示文摘Thermal processes on the Tibetan Plateau(TP)influence atmospheric conditions on regional and global scales.Given this,previous work has shown that soil moisture−driven surface flux variations feed back onto the atmosphere.Whilst soil moisture is a source of atmospheric predictability,no study has evaluated soil moisture−atmosphere coupling on the TP in general circulation models(GCMs).In this study,we use several analysis techniques to assess soil moisture−atmosphere coupling in CMIP6 simulations including:instantaneous coupling indices;analysis of flux and atmospheric behaviour during dry spells;and a quantification of the preference for convection over drier soils.Through these metrics we partition feedbacks into their atmospheric and terrestrial components.Consistent with previous global studies,we conclude substantial inter-model differences in the representation of soil moisture−atmosphere coupling,and that most models underestimate such feedbacks.Focusing on dry spell analysis,most models underestimate increased sensible heat during periods of rainfall deficiency.For example,the model-mean bias in anomalous sensible heat flux is 10 W m−2(≈25%)smaller compared to observations.Deficient dry-spell sensible heat fluxes lead to a weaker atmospheric response.We also find that most GCMs fail to capture the negative feedback between soil moisture and deep convection.The poor simulation of feedbacks in CMIP6 experiments suggests that forecast models also struggle to exploit soil moisture−driven predictability.To improve the representation of land−atmosphere feedbacks requires developments in not only atmospheric modelling,but also surface processes,as we find weak relationships between rainfall biases and coupling indexes. | Joshua TALIB Omar V.MÜLLER Emma J.BARTON Christopher M.TAYLOR Pier Luigi VIDALE | 2023 | Advances in Atmospheric Sciences2023，40，11： | 1 |
| 5 | Benefits of conservation-driven mowing for the EU policy species Gladiolus palustris Gaudin in mountain fen meadows:a case-study in the European Alps显示文摘The sword lily Gladiolus palustris Gaudin is protected on European level and listed in Annexes II and IV of the EC Habitat Directive 92/43/EEC.It grows in nutrient-poor,calcareous meadows in central and eastern Europe.Tree encroachment in montane meadows of the European Alps as a result of recent land use changes and the abandonment of traditional farming practices threaten the survival of this species.Conservation-driven mowing is considered a feasible conservation measure for maintaining high species diversity in abandoned semi-natural grasslands.To assess the effects of tenyears of biennial mowing on a grassland community in the Dolomiti Bellunesi National Park,Italy(Site of Community Importance,Natura 2000 network),ten25 m2 plots were established whereby four plots were placed in the mowed area,four in the non-mowed area and two in a small non-mowed patch of grassland inside the mowed area.In each plot the following variables were recorded,total percentage of plant cover,percentage cover of woody species,percentage cover of herbaceous species,percentage cover and number of flowering ramets of G.palustris and a complete list of species and their percentage abundance.Mowed plots showed a higher species richness than non-mowed plots.The number of G.palustris flowering ramets and percentage cover increased manifold in mowed plots compared to nonmowed plots.The resumption of mowing forconservation purposes undertaken by the managing authority halted the process of tree encroachment and avoided a drastic change in plant composition.Periodic mowing(every second or third year)was demonstrated to be a cost-effective conservation measure in non-productive grasslands to keep grasses at bay in favour of forbs of high conversation value. | Marco CANELLA Gianni POLONIATO Cesare LASEN Simone ORSENIGO Graziano ROSSI Jonas V.MüLLER Thomas ABELI | 2020 | Journal of Mountain Science2020，17，9： | 0 |
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