Interannual Climate Variability Research Articles

Responses and feedbacks of vegetation dynamics to precipitation anomaly over the semiarid area of north China: Evidences from simulations of the WRF‐Noah model

AbstractKnowledge of the responses and feedbacks of vegetation dynamics to interannual climate anomalies in the semiarid area of north China is lacking. This study addresses this issue through climate modelling for 1991–2006 with the Weather Research and Forecast (WRF) model, into which a locally empirical vegetation dynamic (VED) scheme was implemented. The VED scheme was built on the basis of regression models of the leaf area index (LAI), green vegetation fraction (GVF), and surface albedo (ALB) with ambient temperature and humidity as independent variables. Using the update WRF model, the climate simulations were carried out with turning on and off VED, respectively. By comparing the simulations outputs with each other, we find that the interannual variability of precipitation from simulations with turning on VED is larger than that from simulations with turning off VED. The larger interannual variability of precipitation could be explained by VED feedback. Vegetation growth would be more vigorous, as a response, under the more precipitation, because which brings more available water. In turn, vigorous vegetation leads to more evapotranspiration and, hence, precipitable water; as a result, there would be more precipitation. It is reversed for the years with less precipitation. Such interactions between vegetation and precipitation could be summarized as positive feedback loops. This study suggests that the interannual precipitation variability can be enlarged by VED through positive evapotranspiration–precipitation feedback. It is therefore necessary to consider the vegetation dynamics for future downscaled regional climate predictions to pursue more reliable interannual climate variability.

Evaluating contributions of urbanization and global climate change to urban land surface temperature change: a case study in Lagos, Nigeria

This study develops a general method to evaluate the contributions of localized urbanization and global climate change to long-term urban land surface temperature (ULST) change. The method is based on the understanding that long-term annual ULST is controlled by three factors: (1) localized urbanization, (2) global climate change, and (3) interannual climate variation. Then the method removes the interannual climate fluctuations on long-term observed LST time series via linear regression and separates the contributions of urbanization and climate change to the impacts on long-term ULST via urban–rural comparison. The method is applied to Lagos, a fast-growing metropolis in the tropical West Africa, as an example for reference. Combined time-series daily daytime and nighttime MODIS Land Surface Temperature (LST) data over the years of 2003–2021 are used as the representation of land surface temperature. To avoid the potentioal interannual data biase due to uneven availability of data in the rainy seasons over years, only MODIS LST data from dry seasons are used in the study. The results are summarized as follows for Lagos: (1) long-term annual ULST is confirmed to be controlled by the three factors; (2) the proposed method can separate the contribution of the three factors to the ULST; (2) both localized urbanization and global warming are verified to contribute to the ULST increase with positive trends; (3) daytime ULST increased the most in the afternoon time at a mean rate of 1.429 °C per decade, with 0.985 °C (10 year)−1 contributed by urbanization and 0.444 °C (10 year)−1 contributed by climate warming; (4) nighttime ULST in Lagos increased the most after midnight at a rate of 0.563 °C (10 year)−1, with 0.56 °C (10 year)−1 contributed by urbanization and 0.003 °C (10 year)−1 contributed by climate warming; and (5) urbanization is generally responsible for around 60.97% of the urban warming in Lagos. Therefore, the increasing urbaniztion-induced urban heat island effect is the major cause for more heat-related health risks and climate extremes that many urban residents are suffering. The results of this study are of useful reference for both urbanization and climate change related issues in the geo-science field.

Warming effects on tree-ring variables in P. hartwegii Lindl. at the extremes of its natural elevational distribution in central Mexico

In alpine forests, the impact of warming differs at the upper and lower extremes of the elevation gradient causing trees to compensate through different adaptive mechanisms. The objective was to retrospectively evaluate the radial growth response to recent interannual climate variation in Pinus hartwegii trees growing at the extremes of their elevational gradient on two volcanic mountains in central Mexico (La Malinche and Nevado de Toluca). Increment cores collected from 174 P. hartwegii trees were used to estimate time-series of growth ring including ring width and density variables, as well as basal area increment (BAI) and ring biomass (BIO) for 1964–2016. Differences in average radial growth and time-trends of ring variables in response to climate variables were estimated based on correlations of ring variables, BAI, and BIO with inter-annual variation in temperature, rainfall, and length of the frost-free period (FFP). Results showed higher average values of ring width and density variables, as well as BAI and BIO (i.e., higher productivity) at low elevation on both mountains. Time-trends for BAI and BIO were positive at both ends of the elevation gradient, but ring width and density variables followed opposite trends. Inter-annual variation of ring variables was explained more by temperature than by rainfall or FFP; however, temperature was negatively correlated with RW and positively with RD, even though BAI and BIO were positively correlated with temperature (All them with P < 0.001) at both elevational end on both mountains. For most of the ring variables, the total variation explained by the ANOVA model was more related to the linear warming trend (greater than 67%). Warming is affecting radial growth of P. hartwegii trees differently at high versus low elevation on both mountains, showing warning signs from the perspective of functional traits, but not in terms of productivity.

Sensitivity of seasonal air temperature and precipitation, and onset of snowmelt, to Arctic Dipole modes across the Taiga Plains, Northwest Territories, Canada

AbstractNorthern high latitudes are experiencing some of the greatest increases in air temperatures on Earth. Air temperatures (along with other modulating variables including precipitation and the onset of snowmelt) are influenced by atmospheric–oceanic circulation patterns, some of which are persistent and recurrent. One pattern in particular, the Arctic Dipole (AD) anomaly, is a persistent sea‐level pressure teleconnection pattern between the Canadian Archipelago and Barents Sea that has unknown impacts on local climate variability. These patterns may be important, especially in hydro‐ecologically sensitive areas such as Northwest Territories (NWT), Canada where permafrost thaw and ecosystem changes are influenced by interannual climate variability. The goal of this research is to determine the impacts of the AD on local climate (air temperature, precipitation, snowmelt) for a 66‐year period (1950–2015) spanning both latitudinal and longitudinal gradients across NWT from north to south and foothills to plains. Deviations during strong positive and negative modes of the AD index were calculated in reference to the complete 66‐year record. Results showed considerable year‐to‐year variability in the AD pattern, with more frequent strong negative modes during the 2000s. During 1950–2015, there were 64 and 56 occurrences of strong positive and strong negative AD modes, respectively, across all seasons. Spring and summer strong AD modes led to local air temperature anomalies of greater than 0.8°C compared with the long‐term (66 years) mean. Earlier onset of snowmelt, by an average of 3–5 days, was also noted during positive AD modes. Despite strong connectivity between the AD and local air temperature, we found less correspondence between the AD and seasonal precipitation. These findings improve understanding of the impacts of the AD on local weather and climate in NWT and suggest implications for ecosystem change, such as drying and shrubification of northern boreal peatlands and possible connectivity to teleconnection impacts on wildland fire.

The impacts of climate change and cropping systems on soil water recovery in the 0–1500 cm soil profile after alfalfa

Alfalfa (Medicago sativa L.) has played an important role in the “Grain-for-Green” program across the Chinese Loess Plateau but has characteristically high water consumption. Long-term growth significantly reduces soil water storage in the 0–1500 cm profile and results in an obvious decline of alfalfa yield. Fields planted with alfalfa for more than 8 years are often converted to annual crops (winter wheat or corn), but these annual crops planted after alfalfa suffer from low yield due to the reduced soil water content. The objectives of this study were to determine the time required for soil water recovery in the 0–1500 cm profile after fields cropped for 15 years with alfalfa are converted to annual crops and to evaluate the impacts of cropping systems, inter-annual climatic variation, and future climate change on the recovery time. Hydraulic parameters for six soil materials in the 0–1500 cm soil profile were calibrated using the measured soil water content in alfalfa fields from 2005 to 2020 and validated using soil water stable isotopic measurements in 2020. Using the calibrated soil hydraulic parameters, the Hydrus-1D model was used to simulate soil water dynamics in the 0–1500 cm profile and determine the recovery time in two cropping systems (alfalfa-wheat and alfalfa-corn) with 53 climatic realizations generated using random non-repeat sequences drawn from 53 years of observed climatic data (1968–2020) and 20 future climate data series projected by 10 GCM models under RCP 4.5 and 8.5 scenarios (2021–2100), respectively. The results showed that, under the 53 climatic realizations, the recovery time ranged from 14 to 44 years with a median of 27 years for the alfalfa-wheat system and from 11 to 31 years with a median of 18 years for the alfalfa-corn system. Under the RCP 4.5 and 8.5 scenarios, the median recovery times were 37.5 and 42.5 years for the alfalfa-wheat system and 30 and 31.5 years for the alfalfa-corn system, respectively. Considering the long-term effects of alfalfa growth on land productivity, planting areas and growing time of alfalfa should be restricted to maintain sustainable agriculture in the study region.

Species richness, functional traits and climate interactively affect tree survival in a large forest biodiversity experiment

Abstract Tree survival affects forest biodiversity, structure and functioning. However, little is known about feedback effects of biodiversity on survival and its dependence on functional traits and interannual climatic variability. With an individual‐based dataset from a large subtropical forest biodiversity experiment, we evaluated how species richness, functional traits and time‐dependent covariates affected annual tree survival rates from age 3–12 (years) after planting 39 species across a diversity gradient from 1 to 2, 4, 8 and 16 tree species. We found that overall survival rates marginally increased with diversity at the plot level, with large variation among plots within diversity levels. Significant variation among species in survival responses to diversity and changes in these responses with age were related to species functional traits and climatic conditions. Generally, survival rates of conservative species (evergreen, late‐successional species with thick leaves and high carbon to nitrogen ratio but low specific leaf area, leaf phosphorus and hydraulic conductivity) increased with diversity, age and yearly precipitation, whereas acquisitive species showed opposite responses. Synthesis. Our results indicate that interactions between diversity, species functional traits and yearly climatic conditions can balance survival among species in diverse forests. Planting mixtures of species that differ in functional traits in afforestation projects may lead to a positive feedback loop where biodiversity maintains biodiversity, together with its previously reported beneficial effects on ecosystem functioning.

Spatial uncertainty in herbarium data: simulated displacement but not error distance alters estimates of phenological sensitivity to climate in a widespread California wildflower

Herbarium records provide a broad spatial and temporal range with which to investigate plant responses to environmental change. Research on plant phenology and its sensitivity to climate has advanced with the increasing availability of digitized herbarium specimens, but limitations of specimen‐derived data can undermine the inferences derived from such research. One issue that has received little attention is collection site uncertainty (i.e. error distance), a measure of confidence in the location from which a specimen was collected. We conducted comparative analyses of phenoclimatic models to determine whether spatial deviations of 2, 5, 15 or 25 km between recorded and simulated collection sites, as well as the error distance reported in digitized records, affect estimates of the phenological sensitivity of flowering time to annual temperature and precipitation in a widespread annual California wildflower. In this approach, we considered both spatial and interannual variation in climatic conditions. Simulated site displacements led to increasingly weak estimates of phenological sensitivity to temperature and precipitation anomalies with increasing distances. However, we found no significant effect of reported error distance magnitude on estimates of phenological sensitivity to climate normals or anomalies. These findings suggest that the spatial uncertainty of collection sites among specimens of widely collected plant species may not adversely affect estimates of phenological sensitivity to climate, even though real discrepancies and georeferencing inaccuracy can negatively impact such estimates. Collection site uncertainty merits further attention as a potential source of noise in herbarium data, especially for research on how plant traits respond to spatial and interannual climatic variation.

Climate adaptation in the market squid fishery: fishermen responses to past variability associated with El Niño Southern Oscillation cycles inform our understanding of adaptive capacity in the face of future climate change.

Evaluating the strategies fishermen have used to respond to short-term climate variability in the past can help inform our understanding of the adaptive capacity of a fishery in the face of anticipated future change. Using historic fishery landings, climate records, and fishermen surveys, we document how market squid fishermen respond to high seasonal and interannual climate variability associated with the El Niño Southern Oscillation (ENSO) and responses to hypothetical future scenarios of low abundance and range shift. Overall, fishermen have been able to adapt to dramatic shifts in the geographic range of the fishery given their high mobility, with fishermen with larger vessels expressing a willingness to travel greater distances than those with smaller vessels. Nearly half of fishermen stated that they would switch fisheries if market squid decreased dramatically in abundance, although fishermen who were older, had been in the fishery longer, were highly dependent on squid for income, and held only squid and/or coastal pelagic finfish permits were less likely to switch to another fishery in a scenario of lower abundance. While market squid fishermen have exhibited highly adaptive behavior in the face of past climate variability, recent (and likely future) range shifts across state boundaries, as well as closures of other fisheries, constrain fishermen’s choices and emphasize the need for flexibility in management systems. Our study highlights the importance of considering connectivity between fisheries and monitoring and anticipating trans-jurisdictional range shifts to facilitate adaptive fishery management.Supplementary InformationThe online version contains supplementary material available at 10.1007/s10584-022-03394-z.

Inter-Annual Climate Variability Impact on Oil Palm Mapping

The contribution of oil palm plantations to the economic growth of tropical developing countries makes it essential to monitor their expansion into the tropical forest; consequently, most studies focus on improving mapping accuracy while using satellite imagery. However, accuracy can be hampered by atmospheric phenomena that can drastically change climatic conditions in tropical regions, affecting the spectral properties of the vegetation. In this sense, we studied the accuracy of palm plantation mapping by using features from different regions of the electromagnetic spectrum and a data fusion approach, and then compared the changes in accuracy over the years 2016, 2017, and 2018 (two of them with reported climatic anomalies). Optical-based maps obtained higher accuracy than thermal- and microwave-based maps, but they were the most affected by inter-annual climate variability (error margin between 5 and 10%), while thermal-based maps were the least affected (error margin between 8 and 9%). Data fusion combinations improved accuracy and reduced dissimilarities between years (e.g., phenology-based map accuracy changed by up to 20.8%, while phenology fused with microwave features changed by up to 6.8%). We conclude that inter-annual climate variability on land-cover mapping should be considered, especially if the outputs will be used as input in future studies.

Crude Fiber, Ether Extract, and Some Mineral Contents of the Corn Silage Grown at Different Weed Densities

Silage quality has great importance in animal feeding as much as yield. Quality characteristics are generally evaluated over crude protein and digestibility, but parameters related to mineral, total fiber, and sugar contents are also important indicators of silage quality and its nutritive value. Plant characteristics could affect these parameters, as silage material, and thereby, any environmental factors could affect these parameters indirectly. Weeds are one of the main environmental problems in silage corn production and in this study, the effect of weed density (0, 2, 4, 6, 8, 10, 12, 14 weeds m-2) on ether extract, crude ash, crude fiber, starch, and mineral (Mg, Ca, P) contents of the silage was investigated in the years of 2019 and 2020. Inter-annual climatic variations had significant effects on ether extract, crude fiber, starch, Ca, and P contents of corn silage. The effect of weed densities was observed only on starch and Ca content. Increasing weed density decreased the Ca content but starch content showed an irregular variation. Weed density did not cause any significant variations in ether extract, crude ash, crude fiber, Mg, and P contents of the corn silage, but the total amount of the nutrition could be increased in silage by decreasing the competitive ability of the weeds at growth conditions of the silage corn.

Inter-annual variability of catchment water balance in a montane spruce forest

ABSTRACT Climatic conditions in temperate montane forests vary over multiple temporal scales. This study examines the effects of inter-annual climatic variability on the long-term water balance of a small headwater catchment with gradually changing vegetation characteristics. The research is based on direct observations of basic hydrological variables (precipitation, stream discharge), and process-based modelling of difficult-to-measure variables (forest transpiration, wet canopy evaporation, snow sublimation). The catchment water balance is evaluated in terms of the catchment water storage. The uncertainty of the estimated storage changes is expressed as a convolution of partial uncertainties associated with the individual components of catchment water balance. The results suggest a significant decrease of catchment water storage over the study period. The decrease is assumed to be caused by increasing winter temperatures, resulting in a more frequent occurrence of liquid precipitation and less prominent spring snowmelt. Considering vegetation’s conservative water-balance management proved essential for the studied environment.

Mid to late Holocene ENSO variability reconstructed by high-resolution Tridacna Sr/Ca records from the northern part of the South China Sea

The El Niño-Southern Oscillation (ENSO) dominates global interannual climate variability and has important socio-economic and environmental consequences. However, determining the history of ENSO variability and its long-term response to climate forcing remains an ongoing challenge owing to the limit of instrumental records. In this study, ENSO variability was reconstructed using monthly-resolution records of Sr/Ca ratios obtained from subfossil giant clam shells (Tridacna squamosa) during three windows from the 5000 to 3000 yr B.P. in the northern part of the South China Sea (SCS). ENSO variability during the mid to late Holocene was also investigated through comparison with other published monthly Tridacna Sr/Ca records from the northern SCS, and findings show a gradually intensified ENSO variability from the mid to late Holocene. This intensification of ENSO variability over the study period is predicted by model simulations, and is considered to be a consequence of precessional forcing. Our study highlights that the monthly Sr/Ca ratios from Tridacna shells of the northern SCS can be used as a high-resolution indicator of past interannual climate variability and can provide a new perspective for paleo-ENSO reconstructions.

Interannual variation in climate contributes to contingency in post‐fire restoration outcomes in seeded sagebrush steppe

AbstractInterannual variation, especially weather, is an often‐cited reason for restoration “failures”; yet its importance is difficult to experimentally isolate across broad spatiotemporal extents, due to correlations between weather and site characteristics. We examined post‐fire treatments within sagebrush‐steppe ecosystems to ask: (1) Is weather following seeding efforts a primary reason why restoration outcomes depart from predictions? and (2) Does the management‐relevance of weather differ across space and with time since treatment? Our analysis quantified range‐wide patterns of sagebrush (Artemisia spp.) recovery, by integrating long‐term records of restoration and annual vegetation cover estimates from satellite imagery following thousands of post‐fire seeding treatments from 1984 to 2005. Across the Great Basin, sagebrush growth increased in wetter, cooler springs; however, the importance of spring weather varied with sites' long‐term climates, suggesting differing ecophysiological limitations across sagebrush's range. Incorporation of spring weather, including from the “planting year,” improved predictions of sagebrush recovery, but these advances were small compared to contributions of time‐invariant site characteristics. Given extreme weather conditions threatening this ecosystem, explicit consideration of weather could improve the allocation of management resources, such as by identifying areas requiring repeated treatments; but improved forecasts of shifting mean conditions with climate change may more significantly aid the prediction of sagebrush recovery.

Projected ENSO Teleconnection Changes in CMIP6

AbstractThe El Nino–Southern Oscillation (ENSO) has far reaching impacts through atmospheric teleconnections, which make it a prominent driver of global interannual climate variability. As such, whether and how these teleconnections may change due to projected future climate change remains is a topic of high societal relevance. Here, ENSO Surface Temperature (TAS) and Precipitation (PR) teleconnections between the historical and high‐emission future simulations are compared in more than 31 models from Phase 6 of the Coupled Model Intercomparison Project. We find significant future (2081–2100) TAS and PR teleconnection changes over approximately 50% of teleconnected regions in December‐February relative to 1950–2014. The large majority of these significant teleconnection changes suggest that an amplification of the historical teleconnections will occur, however, some regions also display a significant teleconnection dampening. Further to this, in many regions these ENSO teleconnection changes scale with the projected warming level, with higher warming leading to larger teleconnection changes.

COMPARISON OF VEGETATION ANOMALIES TO EL NIÑO-SOUTHERN OSCILLATION IN CHINA AND AUSTRALIA

Abstract. The El Niño-Southern Oscillation (ENSO), as one of the main factors driving extreme climate events, exerts a major influence on interannual climate variability around the world. However, ENSO effects on vegetation, especially regarding the extent, intensity, direction, are not well understood. Here, we characterize and compare the variability in vegetation response to ENSO across China and Australia and explore their underlying mechanisms. Results show that the spatial extent of ENSO-sensitive vegetation differed between China and Australia and across land cover types. For both China and Australia, the intensity and direction of vegetation anomalies were closely related to the type of ENSO events. In particular, vegetation anomalies to the Central-Pacific (CP) type ENSO events were stronger than that to the Eastern-Pacific (EP) type events of the same intensity and generally responded in an opposite way, resulting from different controls of CP-type and EP-type ENSO on precipitation and temperature. Our findings highlight the diverse response of vegetation triggered by different types of ENSO in China and Australia, which can improve our understanding of ENSO impacts on ecosystems in the northern and southern hemispheres.

Spatiotemporal variability and sensitivity of industrial hemp cultivars under variable field conditions

The study of the impact of climate change on crop production requires the examination of cultivar adaptation and performance in response to interannual variability in climate and field conditions. A field test was carried out during four years in Eastern New Brunswick, Canada, to study grain yield, fiber yield and floral cannabidiol content of eight Canadian industrial hemp (Cannabis sativa L., Cannabaceae) cultivars. Hemp performance in terms of grain and fiber production varied greatly between the years. The spatial location of plants in the field was shown to affect the performance of cultivars in different ways for grain and fiber yield. Grain yield was the highest in hot and humid summers, the opposite was observed for cannabidiol content, while fiber production was the highest in cold and humid summers. Our results indicated that grain, fiber or cannabidiol production cannot all be optimized under the given set of climatic conditions and that hemp performance is more sensitive to interannual variability of climatic conditions and intra-field variability than to cultivar effects. Yet, despite the considerable spatiotemporal variability documented, some cultivars have repeatedly exhibited the best performance, demonstrating excellent adaptation to local field conditions.

Interannual variability in summer climate change controls GPP long-term changes

Global environmental change is rapidly altering the dynamics of terrestrial vegetation, with implications for the functioning of the Earth system and the provision of ecosystem services. How vegetation responds to a changing environment is an important scientific issue, but there is a lack of coverage of the relative contributions that long-term variation and interannual variability in vegetation across seasons play in ecosystem response to global change. Here, we used four terrestrial ecosystem models provided by MsTMIP to examine four key environmental drivers of gross primary productivity (GPP) change over the period 1901–2010. Our findings showed that (1) for all seasons, interannual variability in climate change are the main environmental factor controlling seasonal GPP variability. (2) Summer is the key season controlling the variation of annual GPP, and its long-term trend and interannual variability can explain 61.50% of the variation of grassland GPP in China. (3) Interannual variability in summer climate change exceeded the CO2 fertilization effect and nitrogen deposition as the controlling component (more than 40%) of long-term variation in Chinese grassland GPP. These studies highlight the important role of interannual variability in climate in reshaping the seasonality of vegetation growth, and will provide a precursor to future environmental drivers that can be precisely attributed to global vegetation change.

Tidal variations associated with sea level changes in the Northern Bay of Bengal

Changing tides due to non-astronomical factors have been reported globally, with particular emphasis on estuaries and tidal rivers. Changes in tidal amplitude and range, coupled with altered mean sea level (MSL) has the potential to raise high water levels and aggravate the impacts of coastal flooding events. The current study used water level observations to analyze tidal changes over three decades and report its relationship to sea level variations along estuarine zones in the northern Bay of Bengal. The study highlights on the seasonal, inter-annual and long-term variations in tides, with special emphasis on the Ganga-Brahmaputra-Meghna (GBM) delta. The long-term trend analysis of M2 amplitude showed unusual shifts in magnitude and change in pattern after 1993, associated with similar changes in the MSL. This accelerated M2 amplitude (0.27 mm/y2) implied an association to accelerated RWL (Relative Water Level) changes in the Ganges floodplain, due to delta subsidence. These tidal changes were found to be inconsistent with astronomical forcing and the analysis of coherence between M2 and MSL showed 50–70% correlation, which was primarily due to a covarying seasonal signal. The coherence between sea level and tides varied regionally and is influenced by different processes at different timescales. The positive annual coherence between M2 and MSL directly stems from river forcing. The co-occurrence of strong El Niño and strong positive Indian Ocean Dipole events caused perturbations in both the water level and M2, but in a negatively coherent relationship. The study establishes a delayed response of M2 to inter-annual climate variability indices. The differential behavior of tidal constituents along the Chittagong coastal plain and the opposite nature of coherence between M2 and MSL there, relative to that at the GBM delta, imply the prevalence of spatially non-uniform response of tides to sea level fluctuations. The study emphasizes on the need to understand changing tides, for prediction of extreme sea levels and coastal flooding.

Phenological sensitivity and seasonal variability explain climate-driven trends in Mediterranean butterflies.

Although climate-driven phenological shifts have been documented for many taxa across the globe, we still lack knowledge of the consequences they have on populations. Here, we used a comprehensive database comprising 553 populations of 51 species of north-western Mediterranean butterflies to investigate the relationship between phenology and population trends in a 26-year period. Phenological trends and sensitivity to climate, along with various species traits, were used to predict abundance trends. Key ecological traits accounted for a general decline of more than half of the species, most of which, surprisingly, did not change their phenology under a climate warming scenario. However, this was related to the regional cooling in a short temporal window that includes late winter and early spring, during which most species concentrate their development. Finally, we demonstrate that phenological sensitivity—but not phenological trends—predicted population trends, and argue that species that best adjust their phenology to inter-annual climate variability are more likely to maintain a synchronization with trophic resources, thereby mitigating possible negative effects of climate change. Our results reflect the importance of assessing not only species' trends over time but also species’ abilities to respond to a changing climate based on their sensitivity to temperature.

Causal influences of El Niño–Southern Oscillation on global dust activities

Abstract. The dust cycle is an important element of the Earth system, and further understanding of the main drivers of dust emission, transport, and deposition is necessary. The El Niño–Southern Oscillation (ENSO) is the main source of interannual climate variability and is likely to influence the dust cycle on a global scale. However, the causal influences of ENSO on dust activities across the globe remain unclear. Here we investigate the response of dust activities to ENSO using output from Coupled Modeling Intercomparison Project Phase 6 (CMIP6) historical simulations during the 1850–2014 period. The analyses consider the confounding impacts of the Southern Annular Mode, the Indian Ocean Dipole, and the North Atlantic Oscillation. Our results show that ENSO is an important driver of dry and wet dust deposition over the Pacific, Indian, and Southern oceans and parts of the Atlantic Ocean during 1850–2014. Over continents, ENSO signature is found in America, Australia, parts of Asia, and Africa. Further, ENSO displays significant impacts on dust aerosol optical depth over oceans, implying the controls of ENSO on the transport of atmospheric dust. Nevertheless, the results indicate that ENSO is unlikely to exhibit causal impacts on regional dust emissions of major dust sources. While we find high consensus across CMIP6 models in simulating the impacts of ENSO on dust deposition and transport, there is little agreement between models for the ENSO causal impacts on dust emission. Overall, the results emphasize the important role of ENSO in global dust activities.