Effects of Nitrogen Addition on Plant Properties and Microbiomes Under High Phosphorus Addition Level in the Alpine Steppe.

Nitrogen (N) addition can increase the vegetative growth, improve the plant production, and restore the degraded terrestrial ecosystems. But, it simultaneously aggravates the soil phosphorus (P) limitation for plant growth, thus affecting its positive effects on ecosystems. However, how plants and soil microorganisms will change under conditions of high P content in soil is still unknown.

Ambient climate determines the directional trend of community stability under warming and grazing.

Changes in ecological processes over time in ambient treatments are often larger than the responses to manipulative treatments in climate change experiments. However, the impacts of human-driven environmental changes on the stability of natural grasslands have been typically assessed by comparing differences between manipulative plots and reference plots. Little is known about whether or how ambient climate regulates the effects of manipulative treatments and their underlying mechanisms.

Spectroscopic fingerprints to track the fate of aquatic organic matter along an alpine headstream on the Tibetan Plateau.

The fragile aquatic ecosystem on the Tibetan Plateau is severely threatened by human activities and climate change. Dissolved organic matter (DOM) is a vital indicator of surface water quality; however, its comprehensive molecular analysis is challenged due to its low concentration (total organic carbon less than 0.5 mg/L) in alpine areas.

An Intrinsic Geometric Constraint on Morphological Stomatal Traits.

A strong negative non-linear relationship exists between stomatal density (SD) and size (SS) or length (SL), which is of high importance in gas exchange and plant evolution. However, the cause of this relationship has not been clarified. In geometry, SD has an intrinsic relationship with SS or SL, which is defined as a geometric constraint here.

Divergent Responses of Community Reproductive and Vegetative Phenology to Warming and Cooling: Asymmetry Versus Symmetry.

Few studies have focused on the response of plant community phenology to temperature change using manipulative experiments. A lack of understanding of whether responses of community reproductive and vegetative phenological sequences to warming and cooling are asymmetrical or symmetrical limits our capacity to predict responses under warming and cooling. A reciprocal transplant experiment was conducted for 3 years to evaluate response patterns of the temperature sensitivities of community phenological sequences to warming (transferred downward) and cooling (transferred upward) along four elevations on the Tibetan Plateau.

A Noninvasive and Donor-independent Method Simultaneously Monitors Rejection and Infection in Patients With Organ Transplant.

Background: Rejection and infection are 2 major complications affecting the health and survival of patients receiving an allograft organ transplantation. We describe a diagnostic assay that simultaneously monitors for rejection and infection in recipients of kidney transplant by sequencing of cell-free DNA (cfDNA) in plasma.

Methods: By using cfDNA in plasma, we established a noninvasive method that simultaneously monitors rejection and infection in patients with a history of organ transplant.

Effects of temperature, precipitation and carbon dioxide concentrations on the requirements for crop irrigation water in China under future climate scenarios.

Maize, rice, wheat and soybean-the major staple food crops in China-have a crucial role in national food security and economic development. Predictions of changes in the requirements for irrigation water in food crop production under climate change may provide scientific support for the optimum allocation of water resources and measures to mitigate climate change. We conducted a spatial grid-based analysis using projections of future climate generated by a bias-correction and spatial disaggregation multi-model ensemble for three representative concentration pathway scenarios (RCP2.

Spatio-temporal variations in the areas suitable for the cultivation of rice and maize in China under future climate scenarios.

Predictions of changes in the distribution of areas suitable for the cultivation of rice and maize in China under future climate change scenarios may provide scientific support for the optimization of crop production and measures to mitigate climate change. We conducted a spatial grid-based analysis using projections of future climate generated by the National Center for Atmospheric Research Community Climate System Model version 4 for two representative concentration pathway scenarios (RCP2.6 and RCP8.

Responses of sequential and hierarchical phenological events to warming and cooling in alpine meadows.

Organisms' life cycles consist of hierarchical stages, from a single phenological stage (for example, flowering within a season), to vegetative and reproductive phases, to the total lifespan of the individual. Yet phenological events are typically studied in isolation, limiting our understanding of life history responses to climate change. Here, we reciprocally transfer plant communities along an elevation gradient to investigate plastic changes in the duration of sequential phenological events for six alpine species.

Understanding the wide geographic range of a clonal perennial grass: plasticity versus local adaptation.

Both phenotypic plasticity and local adaptation may allow widely distributed plant species to either acclimate or adapt to environmental heterogeneity. Given the typically low genetic variation of clonal plants across their habitats, phenotypic plasticity may be the primary adaptive strategy allowing them to thrive across a wide range of habitats. In this study, the mechanism supporting the widespread distribution of the clonal plant Leymus chinensis was determined, i.

Warming decreased and grazing increased plant uptake of amino acids in an alpine meadow.

Organic nitrogen (N) uptake by plants has been recognized as a significant component of terrestrial N cycle. Several studies indicated that plants have the ability to switch their preference between inorganic and organic forms of N in diverse environments; however, research on plant community response in organic nitrogen uptake to warming and grazing is scarce. Here, we demonstrated that organic N uptake by an alpine plant community decreased under warming with (13)C-(15)N-enriched glycine addition method.

Effects of sampling method on foliar δ (13)C of Leymus chinensis at different scales.

Stable carbon isotope composition (δ (13)C) usually shows a negative relationship with precipitation at a large scale. We hypothesized that sampling method affects foliar δ (13)C and its response pattern to precipitation. We selected 11 sites along a precipitation gradient in Inner Mongolia and collected leaves of Leymus chinensis with five or six replications repeatedly in each site from 2009 to 2011.

Habitat-specific differences in plasticity of foliar δ (13)C in temperate steppe grasses.

A decrease in foliar δ (13)C with increasing precipitation is a common tendency in steppe plants. However, the rate of decrease has been reported to differ between different species or populations. We here hypothesized that plant populations in the same habitat of temperate steppes may not differ in foliar δ (13)C response patterns to precipitation, but could differ in the levels of plasticity of foliar δ (13)C across different habitats.

Foliar δ(13)C response patterns along a moisture gradient arising from genetic variation and phenotypic plasticity in grassland species of Inner Mongolia.

Plants depend upon both genetic differences and phenotypic plasticity to cope with environmental variation over different timescales. The spatial variation in foliar δ(13)C levels along a moisture gradient represents an overlay of genetic and plastic responses. We hypothesized that such a spatial variation would be more obvious than the variation arising purely from a plastic response to moisture change.

Effects of warming and grazing on soil N availability, species composition, and ANPP in an alpine meadow.

Uncertainty about the effects of warming and grazing on soil nitrogen (N) availability, species composition, and aboveground net primary production (ANPP) limits our ability to predict how global carbon sequestration will vary under future warming with grazing in alpine regions. Through a controlled asymmetrical warming (1.2/1.

Gene or environment? Species-specific control of stomatal density and length.

Stomatal characteristics are used as proxies of paleo-environment. Only a few model species have been used to study the mechanisms of genetic and environmental effects on stomatal initiation. Variation among species has not been quantified.

Plant communities: ecosystem stability in Inner Mongolia.

Bai et al. suggest that in China's Inner Mongolia steppe, community-level stability arises from compensatory effects among the principal components at both the species and plant functional group (PFG) levels. By analysing a consistent 19-year data set (1980-98), we show here that their analysis of a 24-year field data set (1980-2003) is called into question by inconsistencies in sampling location and numbers after 1998; the authors' findings are further undermined because they do not distinguish temporal variation from spatial heterogeneity in analysing compensatory effects among species or PFGs.