Transcriptional Changes Underlying the Degradation of Plant Community in Alpine Meadow Under Seasonal Warming Impact.

Global warming is exhibiting a seasonal trend, while different seasons have different warming variations. However, the impact of seasonal warming on plants remains unclear. This study employed Open Top Chambers (OTCs) to simulate future seasonal warming scenarios in alpine meadow.

Consistent time allocation fraction to vegetation green-up versus senescence across northern ecosystems despite recent climate change.

Extended growing season lengths under climatic warming suggest increased time for plant growth. However, research has focused on climatic impacts to the timing or duration of distinct phenological events. Comparatively little is known about impacts to the relative time allocation to distinct phenological events, for example, the proportion of time dedicated to leaf growth versus senescence.

Meta-analysis identifying gut microbial biomarkers of Qinghai-Tibet Plateau populations and the functionality of microbiota-derived butyrate in high-altitude adaptation.

The extreme environmental conditions of a plateau seriously threaten human health. The relationship between gut microbiota and human health at high altitudes has been extensively investigated. However, no universal gut microbiota biomarkers have been identified in the plateau population, limiting research into gut microbiota and high-altitude adaptation.

Asymmetric warming reduces the strength of selection pressure of moderate grazing on reproductive phenology in alpine plants.

Both warming and grazing already affect the reproductive phenology of alpine plants. However, their effects have mostly been studied in isolation, and their interaction is still unclear. In this study, an asymmetric warming (average + 1.

Genome diversity and highland-adaptative variation in Tibet barley landrace population of China.

Barley landraces accumulated variation in adapting to extreme highland environments during long-term domestication in Tibet, but little is known about their population structure and genomic selection traces. In this study, tGBS (tunable genotyping by sequencing) sequencing, molecular marker and phenotypic analyses were conducted on 1,308 highland and 58 inland barley landraces in China. The accessions were divided into six sub-populations and clearly distinguished most six-rowed, naked barley accessions (Qingke in Tibet) from inland barley.

Warming delays but grazing advances leaf senescence of five plant species in an alpine meadow.

Leaf senescence is the final stage in the life cycle of leaves and is critical to plants' fitness as well as to ecosystem carbon and nutrient cycling. To date, most understanding about the responses of leaf senescence to environmental changes has derived from research in forests, but the topic has been relatively neglected, especially under grazing conditions, in natural grasslands. We conducted a 3-year manipulative asymmetric warming with moderate grazing experiment to explore the responses of leaf senescence of five main species in an alpine meadow on the Qinghai-Tibetan Plateau.

The glacial-terrestrial-fluvial pathway: A multiparametrical analysis of spatiotemporal dissolved organic matter variation in three catchments of Lake Nam Co, Tibetan Plateau.

The Tibetan Plateau (TP) is a sensitive alpine environment of global importance, being Asia's water tower, featuring vast ice masses and comprising the world's largest alpine grasslands. Intensified land-use and pronounced global climate change have put pressure on the environment of the TP. We studied the tempo-spatial variability of dissolved organic matter (DOM) to better understand the fluxes of nutrients and energy from terrestrial to aquatic ecosystems in the TP.

Observation-based global soil heterotrophic respiration indicates underestimated turnover and sequestration of soil carbon by terrestrial ecosystem models.

Soil heterotrophic respiration (R ) refers to the flux of CO released from soil to atmosphere as a result of organic matter decomposition by soil microbes and fauna. As one of the major fluxes in the global carbon cycle, large uncertainties still exist in the estimation of global R , which further limits our current understanding of carbon accumulation in soils. Here, we applied a Random Forest algorithm to create a global data set of soil R , by linking 761 field observations with both abiotic and biotic predictors.

Microbial functional changes mark irreversible course of Tibetan grassland degradation.

The Tibetan Plateau's Kobresia pastures store 2.5% of the world's soil organic carbon (SOC). Climate change and overgrazing render their topsoils vulnerable to degradation, with SOC stocks declining by 42% and nitrogen (N) by 33% at severely degraded sites.

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.

Don't judge toxic weeds on whether they are native but on their ecological effects.

The sharp rise in anthropogenic activities and climate change has caused the extensive degradation of grasslands worldwide, jeopardizing ecosystem function, and threatening human well-being. Toxic weeds have been constantly spreading in recent decades; indeed, their occurrence is considered to provide an early sign of land degeneration. Policymakers and scientific researchers often focus on the negative effects of toxic weeds, such as how they inhibit forage growth, kill livestock, and cause economic losses.

Enhanced spring temperature sensitivity of carbon emission links to earlier phenology.

Phenology has a great effect on the carbon cycle. Significant relationships have been well demonstrated between phenology and photosynthesis. However, few studies have been undertaken to characterize relationships between phenology and ecosystem respiration (Re).

Annual ecosystem respiration is resistant to changes in freeze-thaw periods in semi-arid permafrost.

Warming in cold regions alters freezing and thawing (F-T) of soil in winter, exposing soil organic carbon to decomposition. Carbon-rich permafrost is expected to release more CO to the atmosphere through ecosystem respiration (Re) under future climate scenarios. However, the mechanisms of the responses of freeze-thaw periods to climate change and their coupling with Re in situ are poorly understood.

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.

Microbial community responses reduce soil carbon loss in Tibetan alpine grasslands under short-term warming.

Changes in labile carbon (LC) pools and microbial communities are the primary factors controlling soil heterotrophic respiration (R ) in warming experiments. Warming is expected to initially increase R but studies show this increase may not be continuous or sustained. Specifically, LC and soil microbiome have been shown to contribute to the effect of extended warming on R .

Opposite effects of winter day and night temperature changes on early phenophases.

Changes in day (maximum temperature, T ) and night temperature (minimum temperature, T ) in the preseason (e.g., winter and spring) may have opposite effects on early phenophases (e.

Fungal pathogens pose a potential threat to animal and plant health in desertified and pika-burrowed alpine meadows on the Tibetan Plateau.

Intact Tibetan meadows provide significant defense against soil-borne pathogen dispersal. However, dramatic meadow degradation has been observed due to climate change and pika damage, but their impacts on soil-borne pathogens are still unclear. With approximately 40% of the world's population living in Tibetan Plateau and its downstream watersheds, this lack of knowledge should be of great concern.

Warming and land use change concurrently erode ecosystem services in Tibet.

Alpine meadows on the Tibetan Plateau comprise the largest alpine ecosystem in the world and provide critical ecosystem services, including forage production and carbon sequestration, on which people depend from local to global scales. However, the provision of these services may be threatened by climate warming combined with land use policies that are altering if and how pastoralists can continue to graze livestock, the dominant livelihood practice in this region for millennia. We synthesized findings from a climate warming and yak grazing experiment with landscape-level observations in central Tibet to gain insight into the trajectories of change that Tibet's alpine meadows will undergo in response to expected changes in climate and land use.

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.

Plant functional traits mediate reproductive phenology and success in response to experimental warming and snow addition in Tibet.

Global climate change is predicted to have large impacts on the phenology and reproduction of alpine plants, which will have important implications for plant demography and community interactions, trophic dynamics, ecosystem energy balance, and human livelihoods. In this article we report results of a 3-year, fully factorial experimental study exploring how warming, snow addition, and their combination affect reproductive phenology, effort, and success of four alpine plant species belonging to three different life forms in a semiarid, alpine meadow ecosystem on the central Tibetan Plateau. Our results indicate that warming and snow addition change reproductive phenology and success, but responses are not uniform across species.