Increased Precipitation Variability Research Articles

An assessment of the vulnerability and adaptation potential of sugarcane production to water stress, southern Africa

The high spatial variability of precipitation, heightened frequency of droughts and concomitant increases in exposure to water stress across southern Africa due to climate change, presents significant challenges for sugarcane production and the regional sugarcane production value chain. While production has intensified in the past few decades, yields have declined due to increased climatic variability and agronomic management approaches. Increased precipitation variability has enhanced sugarcane vulnerability to water stress and is likely to negatively affect yields. Combining crop simulations and relationships between sugarcane water use and observed rainfall, we introduce a crop productivity ratio (CPR) which assesses sugarcane water stress for six sugarcane mills across southern Africa. The CPR and simulation results were used to assess the adaptation potential or ‘space’ for mill areas that have varying rates of exposure and abilities to adapt to water stress. Simulation results were used to determine the long-term adaption potential of mill areas and to surmise the causes of yield declines. The results were used to offer recommendations to reduce vulnerabilities and enhance adaptation to water stress. We conclude that the amplification of inter-annual precipitation variability will enhance the exposure of sugarcane to water stress and require adaptation interventions. Adapting to external shocks is a multifaceted exercise that requires a holistic approach that includes every aspect of the sugarcane value chain.

Anthropogenic amplification of precipitation variability over the past century.

As the climate warms, the consequent moistening of the atmosphere increases extreme precipitation. Precipitation variability should also increase, producing larger wet-dry swings, but that is yet to be confirmed observationally. Here we show that precipitation variability has already grown globally (over 75% of land area) over the past century, as a result of accumulated anthropogenic warming. The increased variability is seen across daily to intraseasonal timescales, with daily variability increased by 1.2% per 10 years globally, and is particularly prominent over Europe, Australia, and eastern North America. Increased precipitation variability is driven mainly by thermodynamics linked to atmospheric moistening, modulated at decadal timescales by circulation changes. Amplified precipitation variability poses new challenges for weather and climate predictions, as well as for resilience and adaptation by societies and ecosystems.

Disturbance amplifies sensitivity of dryland productivity to precipitation variability.

Variability of the terrestrial global carbon sink is largely determined by the response of dryland productivity to annual precipitation. Despite extensive disturbance in drylands, how disturbance alters productivity-precipitation relationships remains poorly understood. Using remote-sensing to pair more than 5600 km of natural gas pipeline corridors with neighboring undisturbed areas in North American drylands, we found that disturbance reduced average annual production 6 to 29% and caused up to a fivefold increase in the sensitivity of net primary productivity (NPP) to interannual variation in precipitation. Disturbance impacts were larger and longer-lasting at locations with higher precipitation (>450 mm mean annual precipitation). Disturbance effects on NPP dynamics were mostly explained by shifts from woody to herbaceous vegetation. Severe disturbance will amplify effects of increasing precipitation variability on NPP in drylands.

A mixture of grass-legume cover crop species may ameliorate water stress in a changing climate.

Climate change models predict increasing precipitation variability in the mid-latitude regions of Earth, generating a need to reduce the negative impacts of these changes on crop production. Despite considerable research on how cover crops support agriculture in a changing climate, understanding is limited of how climate change influences the growth of cover crops. We investigated the early development of two common cover crop species-crimson clover (Trifolium incarnatum) and rye (Secale cereale)-and hypothesized that growing them in the mixture would ameliorate stress from drought or waterlogging. This hypothesis was tested in a 25-day greenhouse experiment, where the two factors (species number and water stress) were fully crossed in randomized blocks, and plant responses were quantified through survival, growth rate, biomass production and root morphology. Water stress negatively influenced the early growth of these two species in contrasting ways: crimson clover was susceptible to drought while rye performed poorly under waterlogging. Per-plant biomass in rye was always greater in mixture than in monoculture, while per-plant biomass of crimson clover was greater in mixture under drought. Both species grew longer roots in mixture than in monoculture under drought, and total biomass of mixtures did not differ significantly from the more-productive monoculture (rye) in any water condition. In the face of increasingly variable precipitation, growing crimson clover and rye together has potential to ameliorate water stress, a possibility that should be further investigated in field experiments.

Earth system model’s capability of predicting drought-induced crop failure

We used the Meteorological Research Institute Earth System Model to investigate land precipitation and net primary production (NPP, proxy for agricultural production here) in terms of food and water security. In the preindustrial state, the largest decrease in Southeast Asian precipitation (> 20%) occurs along with the largest El Niño and positive phase of the Atlantic multidecadal oscillation, consistent with the 1876-78 Great Drought, leading to the largest decrease in NPP (~ 20%); >2 standard deviations, extreme dryness and crop failure. In relatively arid regions (e.g., India and northeastern Brazil), the largest decreases in precipitation and NPP reach ≥ 50%, particularly 80 ~ 90% in Deccan, India. In the 21st century warming projection (Shared Socioeconomic Pathways 5-8.5, the largest CO2 emission scenario), the interannual variability of precipitation and NPP in Monsoon Asia increase under the influence of enhanced El Niño-Southern Oscillation. Although the increased precipitation variability indicates more frequent severer droughts than in the preindustrial state, this severity does not influence NPP so much: the increased NPP variability is negligible compared to the significant increase in normal NPP by CO2 fertilization effect, which indicates usually rich harvests. Compared to a recent severe crop failure (− 25% in Japan in 1993), the simulated preindustrial drought-induced NPP decreases of ≥ 50% in parts of low latitudes are extraordinarily large enough to correspond to devastating crop failures. The model indicates that great famines before the 20th century were natural in origin, and that manmade factors, such as harsh taxes and hoarding and export of grain, made the famines more devastating.

Precipitation and hydrological extremes during the warm season in response to climate change: the example from the Polish Carpathians

This study assesses the long-term variability of extreme precipitation events in the Carpathian region of Poland in relation to climate change and its potential impact on river regime. Focusing on eight catchments with undisturbed runoff regimes, the research utilized daily data from May to October between 1951 and 2022. This data included precipitation totals from 23 gauging stations, discharge values from eight water level gauging stations, and gridded precipitation data from the E-OBS dataset. Additionally, future projections for 2026–2060 under two RCP scenarios (4.5 and 8.5) were generated using five GCM-RCM model combinations from the EURO-CORDEX simulations. The study explored the relationship between precipitation and discharge, using probability techniques to identify extreme events. This study highlights the strong linkages between extreme precipitation and discharge in the region, indicating an elevated flood risk due to increased precipitation variability and volume. Despite no significant trends in the frequency of precipitation extremes being observed in the historical analysis, an increase in seasonal precipitation totals is projected, although with considerable uncertainty.

Variation in the strength and stationarity of southern longleaf pine seasonwood climate-growth relationships

Climate change is predicted to cause asymmetric warming and increased precipitation variability across different seasons. These changes and their effects may be captured in subannual seasonwood measures of tree growth (i.e., earlywood, latewood). Longleaf pine is a foundational tree species throughout the broad southeastern U.S. Its latewood growth may be more variable and sensitive to climate change than earlywood, but prior studies have geographical and ecological sampling limitations. Here, we use dendroecological methods to develop ring-width and seasonwood (earlywood, latewood, and adjusted latewood) chronologies and analyze climate-growth relationships for longleaf pine from eight sites in the Southern Coastal Plain of Florida, USA. Sites spanned a range of environmental conditions to generate an ecologically representative dataset. We evaluated chronology strength and variability and determined monthly and seasonal correlations with precipitation and temperature. We furthermore evaluated climate-growth stationarity using a moving response function and bootstrapped transfer function stability tests. We found adjusted latewood chronologies were most climatically sensitive although totalwood chronologies had higher interseries correlations. Totalwood measurements were more variable than early- or latewood year to year. Tree growth was positively correlated with summer precipitation at six out of eight sites and negatively correlated with late summer maximum temperatures at six out of eight sites. Negative relationships between growth and maximum temperature occurred earlier in the year at southern sites and the positive effect of June precipitation on tree growth was notable, found at six out of eight sites. However, the strength and significance of climate-growth relationships were non-stationary through space and time, with shifts largely occurring post-1950s. Longleaf pine at its southern range extent was less sensitive to climate than more northern populations, which may indicate non-linear responses to warming captured at the species’ range margin. Our results highlight dynamic climate-growth relationships related to the broad range of environmental conditions where longleaf pine is found.

Declined terrestrial ecosystem resilience

AbstractTerrestrial ecosystem resilience is crucial for maintaining the structural and functional stability of ecosystems following disturbances. However, changes in resilience over the past few decades and the risk of future resilience loss under ongoing climate change are unclear. Here, we identified resilience trends using two remotely sensed vegetation indices, analyzed the relative importance of potential driving factors to resilience changes, and finally assessed the risk of future resilience loss based on the output data of eight models from CMIP6. The results revealed that more than 60% of the ecosystems experienced a conversion from an increased trend to a declined trend in resilience. Attribution analysis showed that the most important driving factors of declined resilience varied regionally. The declined trends in resilience were associated with increased precipitation variability in the tropics, decreased vegetation cover in arid region, increased temperature variability in temperate regions, and increased average temperature in cold regions. CMIP6 reveals that terrestrial ecosystems under SPP585 are expected to experience more intense declines in resilience than those under SSP126 and SSP245, particularly in cold regions. These results highlight the risk of continued degradation of ecosystem resilience in the future and the urgency of climate mitigation actions.

Nitrogen addition does not alter symmetric responses of soil respiration to changing precipitation in a semi-arid grassland

Concurrent changing precipitation regimes and atmospheric nitrogen (N) deposition can have profound influences on soil carbon (C) cycling. However, how N enrichment regulates the responses of soil C fluxes to increasing variability of precipitation remains elusive. As part of a field precipitation gradient experiment with nine levels of precipitation amounts (−60 %, −45 %, −30 %, −15 %, ambient precipitation, +15 %, +30 %, +45 %, and +60 %) and two levels of N addition (0 and 10 g N m−2 yr−1) in a semi-arid temperate steppe on the Mongolian Plateau, this work was conducted to investigate the responses of soil respiration to decreased and increased precipitation (DP and IP), N addition, and their possible interactions. Averaged over the three years from 2019 to 2021, DP suppressed soil respiration by 16.1 %, whereas IP stimulated it by 27.4 %. Nitrogen addition decreased soil respiration by 7.1 % primarily via reducing microbial biomass C. Soil respiration showed symmetric responses to DP and IP within all the four precipitation variabilities (i.e., 15 %, 30 %, 45 %, and 60 %) under ambient N. Nevertheless, N addition did not alter the symmetric responses of soil respiration to changing precipitation due to the comparable sensitivities of microbial biomass and root growth to DP and IP under the N addition treatment. These findings indicate that intensified precipitation variability does not change but N addition could alleviate soil C releases. The unchanged symmetric responses of soil respiration to precipitation variability under N addition imply that N deposition may not change the response pattern of soil C releases to predicted increases in precipitation variability in grasslands, facilitating the robust projections of ecosystem C cycling under future global change scenarios.

Positive asymmetric responses indicate larger carbon sink with increase in precipitation variability in global terrestrial ecosystems

<p>Climate changes have caused high inter-annual variability in precipitation. However, how the terrestrial ecosystem responds to precipitation variability remains unclear. Using global remote sensing data and a meta-analysis by synthesizing 800 pairwise observations of experimental manipulations worldwide, we quantified the responses of the terrestrial ecosystem net carbon productivity (NEP) to precipitation variability. The results indicate that NEP displays a positive asymmetry in response to precipitation change, e.g., the magnitude of the increase in NEP (33.4%) under water-addition treatments is larger than that of the decline in NEP (-24.62%) under water-reduction treatments. The positive asymmetry of NEP in arid regions (< 500 mm) is larger than that in humid regions (> 500 mm). The former is mainly due to the positive asymmetry in vegetation productivity, while the latter results from the respiration process, i.e., the decrease in soil respiration in water-reduction treatments is stronger than in water-addition treatments. Furthermore, land models reproduce a positive NEP asymmetry in response to precipitation change, but display poor performance in ecosystem respiration (ER) responses owing to uncertainties in simulating soil water content (SWC). The positive asymmetry of NEP in this study implies that the increase in precipitation variability (except extreme anomalies) is conducive to high carbon sink in the global terrestrial ecosystem. Meanwhile, the performance of the models when simulating SWC in response to precipitation in humid regions needs to be further improved to better predict the carbon sink in the terrestrial ecosystem.</p>

Altered intra-annual precipitation patterns affect the N-limitation status of soil microorganisms in a semiarid alpine grassland

The ongoing intensification of the hydrological cycle due to global climate change alters intra-annual precipitation variability. Changes in precipitation patterns lead to disparities in soil moisture; however, the responses of soil extracellular enzyme activities (EEAs) and microbial metabolism limitations to them is unclear. This study conducted an in situ field experiment in the alpine grasslands of the Kunlun Mountains to simulate the same amount of precipitation but change the distribution time of precipitation within the plant growing season. We examined the effects of variability in intra-annual precipitation patterns on the stoichiometry of topsoil (0–5 and 5–20 cm) properties, microbial biomass, and EEAs. Results showed that altered precipitation patterns significantly increased soil moisture’s disparity index (D) by 57 %–89 %. The activity of nitrogen-acquiring enzymes (L-leucine aminopeptidase) was increased by 20.82–32.08 % (P < 0.05) with increased variability of precipitation, while phosphorus-acquiring enzymes (Acid phosphatase) and carbon-acquiring enzymes (β-glucosidase) both decrease by 9.25–23.35 % and by 17.86–33.04 %, respectively (P < 0.05). We determined that soil microorganisms in the study region were metabolism-limited by nitrogen (vector angles < 45◦), and increased precipitation variability exacerbated nitrogen limitation (decrescent vector angles) and alleviated carbon limitation (shortened vector length). In addition, soil EEAs can be both interactively influenced by biotic and abiotic factors, with abiotic factors (i.e., D, soil organic carbon content, and soil total nitrogen content) having a stronger effect. Our study provides an effective strategy for regulating soil EEAs, microbial biomass, and microbial metabolism limitation and contributes to developing nutrient management and restoration strategies in semiarid alpine grassland ecosystems.

Increasing precipitation deteriorates the progress of pesticide reduction policy in the vulnerable watershed

Precipitation variation profoundly affects agricultural development and increases the diffuse pollution risk, which may weaken the positive effects of pesticide reduction policy. This study aimed to analyze the response of pesticide discharge loads in the large vulnerable watershed to pesticide application intensity and precipitation variance before and after implementing the pesticide reduction policy. We integrated empirical models, field observation and statistics to explore the sensitive factors of the typical pesticide atrazine before and after the pesticide reduction policy in the Yellow River Watershed. The results showed that the implementation of pesticide reduction policy effectively decreased the annual discharge load of atrazine within the watershed. In addition, the most sensitive factor of atrazine discharge loads shifted from precipitation to the atrazine application intensity after implementing the pesticide reduction policy. However, the discharge loads of atrazine significantly increased in an unusual high precipitation year in the context of increasing precipitation variability.

Increasing precipitation variability and climate-growth responses of five tree species in North Carolina, USA

We examined the effects of increasing summertime precipitation variability from 1950 to 2022 on the radial-growth responses of five tree species native to central North Carolina, USA. Tree-ring data were collected from chestnut oak, post oak, longleaf pine, shortleaf pine, and Virginia pine and processed following standard dendrochronology procedures. Adjusted latewood chronologies for each species were created and correlated with either monthly or multi-monthly combinations of summertime precipitation for above average (AA, > 1 σ above mean), below average (BA, <−1 σ below mean), and near average (NA, <−1, and 1 > σ) precipitation years. June–September precipitation variability and other summertime monthly combinations significantly increased during the study period, with a 10.2% increase in AA/BA years during the 21st century. Climate-growth correlations ranged from 0.40–0.51 using all years within the study period. However, using AA and BA years exclusively, climate-growth responses ranged from 0.44–0.71, with post oak and longleaf pine experiencing significantly higher correlations. No significant changes in climate-growth responses occurred for chestnut oak, shortleaf pine, and Virginia pine. These findings suggest the effects of increased precipitation variability on climate-growth responses are species-dependent and affected by the precipitation classification (i.e. AA or BA years). These responses help explain temporal variations in the strength of climate-growth responses, particularly for some species, and offer additional considerations for dendroclimatological research.

A Shift From Temperature to Water as the Primary Driver for Interannual Variability of the Tropical Carbon Cycle

AbstractThe relative importance of temperature and water constraints on the tropical carbon cycle is an ongoing debate. Here we combine multiple independent tropical ecosystem carbon exchange simulations with satellite observations and show that the primary control for the tropical carbon cycle has shifted recently from temperature to water. We examined the response of tropical ecosystem processes to climate change and suggest that the emerging role of water as the dominant driver for the tropical carbon cycle is attributable to increased precipitation variability, which is associated with intensified extreme drought and wet conditions. Extreme conditions strengthen water's regulation of ecosystem carbon exchange. The weakening influence of temperature is explained by the previously additive effects of temperature on ecosystem productivity and respiration now becoming opposing effects owing to amplified drought conditions, resulting in a reduction to the net effect of temperature on ecosystem carbon exchange.

Climatic variability during the 4.2 ka event: Evidence from a high-resolution pollen record in southeastern China

The 4.2 ka event was a period of global drought and climate cooling linked to the widespread disruption of Neolithic culture. However, the detailed climatic changes during this period are not completely understood. In this paper, we report a high-resolution pollen record for the Dayanghu wetland in the Zhejiang region of southeastern China, which we use to infer mean annual precipitation (MAP) fluctuations during the period spanning 4600–4000 calendar years before present (cal. yr BP). There was a long-term trend of decreasing MAP during this interval, consistent with weakening of the East Asian Summer Monsoon since the mid-Holocene. This trend was punctuated by episodes of relatively high MAP at 4350–4320, ca. 4260, and 4220–4200 cal. yr BP, and extreme droughts at 4200 and 4150 cal. yr BP. We propose that solar activity promoted El Niño events and contributed to dramatic MAP fluctuations in the Dayanghu wetland. La Niña events and negative-phase intervals of the Pacific Decadal Oscillation may have been responsible for the extreme drought at 4200–4150 cal. yr BP. In summary, we propose a close relationship between MAP and solar forcing, with short-term enhanced solar activity increasing the intensity of the East Asian Summer Monsoon and contributing to increasing decadal variability in the inner tropical Pacific, which ultimately leads to increased precipitation variability in southeast China. The results improve our understanding of the detailed climatic features of the 4.2 ka event.

Water Resources in the Truckee Meadows

Over the last century water supply and demand conditions have changed in northern Nevada. Climate change is causing increased temperatures, evaporation, and declining snowpack storage (Siirila-Woodburn, 2021). There is considerable uncertainty about the future magnitude of annual precipitation (Lynn, et al., 2015), but increased variability is expected (Zhang et al., 2021; Gonzalez et al., 2018). Increased precipitation variability may translate into longer and more severe droughts or more frequent flooding. Continued warming trends will likely result in more precipitation falling as rain instead of snow, which has the potential to decrease the region’s snowpack (Harpold et al., 2017; Hatchett et al., 2018; Cooper et al., 2016). Changing conditions will require changes in water resources management strategies to improve efficiencies, and sustained actions that conserve available resources and ongoing adaptive management. The Truckee Meadows Water Authority (TMWA) manages its water resources to provide a resilient and reliable water supply for the region. TMWA is continuing its adaptive management strategy by analyzing a broad range of future conditions and planning for solutions to deal with the changing climate and increasing population. This article provides an overview of TMWA, its service area, supply sources, water rights, future supply scenarios, and adaptive management strategies (TMWA, 2020).

The effects of climate, natural disturbances, and human occupation on the rainforest boundary at the eastern foothills of Northern Patagonian Andes since the Late Glacial period

Available studies on the vegetation development in Patagonia cluster along the forest-steppe ecotone, whilst little information is available from within the mountains. This study investigates shifts in the eastern boundary of rainforest taxa during the Late Glacial and Holocene periods. Continuous sections of highly organic sediments with several interbedded tephra layers were obtained at El Laguito del Morro Lake (41° 32′ 24.4″ S, 71° 47’ 50.0” W), which were analyzed for pollen and macro charcoal. Additional macrofossil analysis was conducted to support the interpretations of pollen data and gain reliable material for radiocarbon dating. Fluctuations in regional precipitation were inferred from changes in the adjacent peatbog. The pollen record documents five distinct periods of forest diversity and structure. Late Glacial and early Holocene vegetation were characterized by a combination of Podocarpus and Cupressaceae pollen which has no modern analogue. Taxa in question became rare, and or gradually disappeared around 10,300 cal yr BP when Nothofagus dombeyi type pollen increases but fluctuates. With the overall decline of charcoal concentrations around 7500 cal. BP Nothofagus dombeyi-type pollen stabilizes and dominates the diagram. After the rise in charcoal concentrations around 4000 cal yr BP also the overall vegetation composition changes around 3600 cal yr BP, with the rise of Cupressaceae pollen attributed to Austrocedrus chilensis marking the establishment of the modern vegetation structure. The last stronger change in vegetation composition is characterized by the expansion of the shrub Discaria sp. 770 cal yr BP. Charcoal and pollen data show a clear link between changes in fire regime and vegetation composition, however, changes in climate were most likely the main driver for both. During the Late Glacial period, a rainforest developed under cool temperatures and high moisture. Severity of fires decreased during a cold reversal period from ca. 12,800 to 11,300 cal yr BP. During Early Holocene, increased seasonality, volcanism-derived disturbances, and low-frequency surficial fires, enhanced Nothofagus dombeyi forest establishment. The expansion of the mixed Nothofagus dombeyi - Austrocedrus chilensis forest occurred under increased precipitation variability and the increase of low severity fires related to the establishment of El Niño Southern Oscillation and the Southern Annular Mode during the Late Holocene. Scrub expansion occurred during historical times because of induced fires.

Future changes of circulation types and their effects on surface air temperature and precipitation in the SMHI large ensemble

Being strongly influenced by internal climate variability, the atmospheric circulation response to greenhouse gas forcing in the future climate is uncertain. This study addresses atmospheric circulation through representative circulation types (CTs) and investigates the CTs’ changes with respect to frequency and effect on surface temperature and precipitation over a pan-Scandinavian domain. The analysis is based on the Swedish Meteorological and Hydrological Institute Large Ensemble performed with EC-Earth3: 50-member ensembles from one historical and six scenario simulations for the twenty-first century are used to assess internal variability and significance of changes. Although the results show no strong future changes in the CTs’ sea level pressure patterns, CT frequency changes suggest a future extension of summer conditions towards spring and autumn and point towards a clearer distinction between summer and winter. The present-climate CT effect on surface temperature is found to generally weaken which is consistent with a general decrease in temperature variability. Largest-scale and strongest temperature effect changes are projected between March and May for CT3, a cyclone towards the east of the domain associated with a domain-wide cooling effect that will likely be decreased towards the end of the twenty-first century. Similarly but of opposite sign, the CT effect on precipitation is strengthening as a result of the increased precipitation variability. Here, largest-scale and strongest effect enhancement is found for CT6, thus increasing its wetting effect over southern Scandinavia and drying effect west of the Scandes. Changes are generally largest towards the end of the twenty-first century and tend to increase with the forcing strength, thus maximizing for SSP585.

Global vegetation resilience linked to water availability and variability

Quantifying the resilience of vegetated ecosystems is key to constraining both present-day and future global impacts of anthropogenic climate change. Here we apply both empirical and theoretical resilience metrics to remotely-sensed vegetation data in order to examine the role of water availability and variability in controlling vegetation resilience at the global scale. We find a concise global relationship where vegetation resilience is greater in regions with higher water availability. We also reveal that resilience is lower in regions with more pronounced inter-annual precipitation variability, but find less concise relationships between vegetation resilience and intra-annual precipitation variability. Our results thus imply that the resilience of vegetation responds differently to water deficits at varying time scales. In view of projected increases in precipitation variability, our findings highlight the risk of ecosystem degradation under ongoing climate change.

Responses of terrestrial ecosystem productivity and community structure to intra-annual precipitation patterns: A meta-analysis.

The productivity and community structures of terrestrial ecosystems are regulated by total precipitation amount and intra-annual precipitation patterns, which have been altered by climate change. The timing and sizes of precipitation events are the two key factors of intra-annual precipitation patterns and potentially drive ecosystem function by influencing soil moisture. However, the generalizable patterns of how intra-annual precipitation patterns affect the productivity and community structures of ecosystems remain unclear. We synthesized 633 observations from 17 studies and conducted a global meta-analysis to investigate the influences of intra-annual precipitation patterns on the productivity and community structures of terrestrial ecosystems. By classifying intra-annual precipitation patterns, we also assess the importance of the magnitude and timing of precipitation events on plant productivity. Our results showed that the intra-annual precipitation patterns decreased diversity by 6.3% but increased belowground net primary productivity, richness, and relative abundance by 16.8%, 10.5%, and 45.0%, respectively. Notably, we found that the timing uniformity of precipitation events was more important for plant productivity, while the plant community structure benefited from the increased precipitation variability. In addition, the relationship between plant productivity and community structure and soil moisture dynamic response was more consistent with the nonlinear model. The patterns of the responses of plant productivity and community structure to altered intra-annual precipitation patterns were revealed, and the importance of the timing uniformity of precipitation events to the functioning of production systems was highlighted, which is essential to enhancing understanding of the structures and functions of ecosystems subjected to altered precipitation patterns and predicting their changes.