Rising Spring Temperatures Research Articles

Multi-Scale Flood Mapping under Climate Change Scenarios in Hexagonal Discrete Global Grids

Among the most prevalent natural hazards, flooding has been threatening human lives and properties. Robust flood simulation is required for effective response and prevention. Machine learning is widely used in flood modeling due to its high performance and scalability. Nonetheless, data pre-processing of heterogeneous sources can be cumbersome, and traditional data processing and modeling have been limited to a single resolution. This study employed an Icosahedral Snyder Equal Area Aperture 3 Hexagonal Discrete Global Grid System (ISEA3H DGGS) as a scalable, standard spatial framework for computation, integration, and analysis of multi-source geospatial data. We managed to incorporate external machine learning algorithms with a DGGS-based data framework, and project future flood risks under multiple climate change scenarios for southern New Brunswick, Canada. A total of 32 explanatory factors including topographical, hydrological, geomorphic, meteorological, and anthropogenic were investigated. Results showed that low elevation and proximity to permanent waterbodies were primary factors of flooding events, and rising spring temperatures can increase flood risk. Flooding extent was predicted to occupy 135–203% of the 2019 flood area, one of the most recent major flooding events, by the year 2100. Our results assisted in understanding the potential impact of climate change on flood risk, and indicated the feasibility of DGGS as the standard data fabric for heterogeneous data integration and incorporated in multi-scale data mining.

Environmental controls of harmful cyanobacterial blooms in Chinese inland waters

Harmful cyanobacterial blooms (CyanoHABs) are expanding world-wide, adversely affecting aquatic food production, recreational and tourism activities and safe drinking water supplies. China's inland waters have been increasingly threatened by CyanoHABs during the past several decades. The environmental factors controlling CyanoHABs are highly variable in space and time in China due to significant variations in climate, geography, geological and geochemical conditions among its many regions. Here, we synthesize diverse examples among Chinese water bodies regarding interactive effects of anthropogenic, climatic and geographic drivers influencing CyanoHAB potentials and dynamics in lakes and reservoirs; in order to provide a perspective and integrative approach to mitigating CyanoHABs. In China's many shallow water bodies, water quality is highly susceptible to human activity and to changing climatic and hydrological conditions, when compared to deeper lakes. Rapid increases in population, economic activity, and wastewater have accelerated CyanoHABs in China since 1980s, especially in the heavily urbanized, agricultural and industrial regions in the middle and lower Yangtze River basins. Climatic changes have provided an additional catalyst for expansion of CyanoHABs. In particular, rising spring temperatures have accelerated the onset and proliferation of Microcystis spp, blooms in the middle and lower reaches of Yangtze River basin. Large hydroelectric and water supply projects, like the Three Gorges Reservoir (TGR), have altered hydrological regimes, and have led to an increase of CyanoHABs in reservoirs and tributaries due to increases in water residence times. Manipulating water level fluctuations in the TGR may prove useful for controlling CyanoHAB in its tributary bays. Overall,CyanoHAB mitigation strategies will have to incorporate both N and P input reductions in these shallow systems. Furthermore, nutrient reduction strategies must consider climate change-induced increases in extreme weather events, including more intense rainfall and protracted heat waves and droughts, which can extend the magnitudes and duration of CyanoHABs. Ensuring the maintenance of natural hydrologic connectivity between lakes and rivers is of utmost importance in mitigating CyanoHABs throughout China.

Shifts in migration phenology under climate change: temperature vs. abundance effects in birds

In migratory birds, increasing temperatures have been linked to earlier arrival to breeding sites, enabling an earlier start of breeding and leading to changes in abundance. Long-term population trends may thus reflect a species capacity to respond to climate change. However, when a species is more abundant, it is also more easily detectable by observers, leading to an earlier detection of its arrival. Therefore, investigations of the drivers of shifts in apparent arrival dates to breeding sites and population trends remain challenging. Here, we formulate predictions aiming to disentangle the different drivers, analysing spring arrival dates and population changes of 52 migratory birds in a Central European country, the Czech Republic, from 1994 to 2017. If shifts in arrival dates are driven by increasing spring temperatures, migrants should arrive earlier in a warmer year and their abundance should increase in the subsequent year due to earlier breeding. If earlier migrant arrival results from their increased detectability caused by higher abundance, then migrants should arrive earlier in the same years when their abundance is high. We found clear support for the former prediction, indicating that climate change drives the earlier arrival of migrants irrespective of changes in their detectability. Moreover, species advancing their arrival to a greater degree had more positive population trends, and responses to rising spring temperatures in the Czech Republic became weaker with increasing migration distance. Therefore, climate change drives population trends of migratory species according to their capacity to adjust their arrival date to variations in spring temperatures.

Recent spring warming limits near‐treeline deciduous and evergreen alpine dwarf shrub growth

AbstractWarming may lead to a cover increase of tundra shrubs and a north‐ and upward shift of treelines. The latter may be inhibited by a densification of shrub stands. However, the climatic drivers of near‐treeline shrub growth are relatively unexplored, especially that of shrub species from different functional groups growing intertwined, in competition for light and resources. We measured ring widths from two dominant dwarf shrubs species, the deciduous Betula nana and the evergreen Empetrum nigrum ssp. hermaphroditum from a near‐treeline alpine ridge in the Central Norwegian Scandes, and tested the influence of on‐site and regional climate, and changes therein, over the past 55 yr. Radial growth of B. nana was found to be negatively influenced by early summer (June–July) precipitation, possibly related to low amounts of photosynthetically active radiation and nitrogen leaching, and positively by July temperatures. That of E. hermaphroditum was positively correlated with late summer (July–August) temperatures. In recent decades, the influence of summer climate on both species’ growth has declined and been replaced by a negative influence of May temperatures. Rising spring temperatures in recent decades have likely advanced key phenology events in B. nana and E. hermaphroditum, such as budburst and flowering. This may have left the shrubs’ soft tissues vulnerable to late frost events, which in recent decades occur more frequently after the advanced start of the growing season, resulting in suppressed growth.

Estimating the ability of plants to plastically track temperature-mediated shifts in the spring phenological optimum.

One consequence of rising spring temperatures is that the optimum timing of key life-history events may advance. Where this is the case, a population's fate may depend on the degree to which it is able to track a change in the optimum timing either via plasticity or via adaptation. Estimating the effect that temperature change will have on optimum timing using standard approaches is logistically challenging, with the result that very few estimates of this important parameter exist. Here we adopt an alternative statistical method that substitutes space for time to estimate the temperature sensitivity of the optimum timing of 22 plant species based on >200000 spatiotemporal phenological observations from across the United Kingdom. We find that first leafing and flowering dates are sensitive to forcing (spring) temperatures, with optimum timing advancing by an average of 3days °C-1 and plastic responses to forcing between -3 and -8days °C-1 . Chilling (autumn/winter) temperatures and photoperiod tend to be important cues for species with early and late phenology, respectively. For most species, we find that plasticity is adaptive, and for seven species, plasticity is sufficient to track geographic variation in the optimum phenology. For four species, we find that plasticity is significantly steeper than the optimum slope that we estimate between forcing temperature and phenology, and we examine possible explanations for this countergradient pattern, including local adaptation.

Climate change upends selection on ornamentation in a wild bird.

Secondary sexual traits have high heritabilities and are exposed to strong, environmentally sensitive selection, and so are expected to evolve rapidly in response to sustained environmental change. We examine the eco-evolutionary dynamics of ornament expression in a long-term study population of collared flycatchers, Ficedula albicollis, in which forehead patch size, which positively influences male reproductive success, declined markedly over 34 years. Annual fitness selection on forehead patch size switched from positive to negative during the study, a reversal that is accounted for by rising spring temperatures at the breeding site: highly ornamented males were selectively favoured following cold breeding seasons but selected against following warm breeding seasons. An 'individual animal model' describes a decline in the genetic values of breeding males during the study, which simulations showed was unlikely to result from drift alone. These results are thus consistent with adaptive evolution of a sexually selected trait in response to climate change.

Contrasting effects of climate change on the timing of reproduction and reproductive success of a temperate insectivorous bat

AbstractWe used long‐term datasets to analyse (1) the patterns of covariation between basic climatic variables (temperature and rainfall) and the timing of reproduction and reproductive success; and (2) long‐term trends in both reproductive parameters of a maternity colony of Daubenton's bats Myotis daubentonii in South Bohemia, Czech Republic. The mean April temperature was the best predictor of the timing of reproduction. The higher the April temperature, the earlier the first neonates appeared. The mean date of first parturition was June 4, but it advanced significantly by c. 11 days between 1970 and 2012. Similarly, the mean April temperature increased over the study period by c. 2.7°C. Between 1999 and 2012, the mean reproductive success (proportion of reproductive females) was 74%, but varied between 33% (2009) and 93% (2006). It was negatively related to May–July precipitation. Thus, reproductive success was lower in years with increased rainfall. Given the published evidence that advancement in parturition is positively related to survival of juvenile bats rising spring temperatures may have a beneficial influence on the population dynamics of Daubenton's bats. However, increased incidence of climatic extremes, such as excessive summer rainfall, may largely buffer this effect. Consequently, populations of temperate insectivorous bats may experience increasing environmental stress under continuing climate change.

Climate change, breeding date and nestling diet: how temperature differentially affects seasonal changes in pied flycatcher diet depending on habitat variation

1. Climate warming has led to shifts in the seasonal timing of species. These shifts can differ across trophic levels, and as a result, predator phenology can get out of synchrony with prey phenology. This can have major consequences for predators such as population declines owing to low reproductive success. However, such trophic interactions are likely to differ between habitats, resulting in differential susceptibility of populations to increases in spring temperatures. A mismatch between breeding phenology and food abundance might be mitigated by dietary changes, but few studies have investigated this phenomenon. Here, we present data on nestling diets of nine different populations of pied flycatchers Ficedula hypoleuca, across their breeding range. This species has been shown to adjust its breeding phenology to local climate change, but sometimes insufficiently relative to the phenology of their presumed major prey: Lepidoptera larvae. In spring, such larvae have a pronounced peak in oak habitats, but to a much lesser extent in coniferous and other deciduous habitats. 2. We found strong seasonal declines in the proportions of caterpillars in the diet only for oak habitats, and not for the other forest types. The seasonal decline in oak habitats was most strongly observed in warmer years, indicating that potential mismatches were stronger in warmer years. However, in coniferous and other habitats, no such effect of spring temperature was found. 3. Chicks reached somewhat higher weights in broods provided with higher proportions of caterpillars, supporting the notion that caterpillars are an important food source and that the temporal match with the caterpillar peak may represent an important component of reproductive success. 4. We suggest that pied flycatchers breeding in oak habitats have greater need to adjust timing of breeding to rising spring temperatures, because of the strong seasonality in their food. Such between-habitat differences can have important consequences for population dynamics and should be taken into account in studies on phenotypic plasticity and adaptation to climate change.

CLIMATE CHANGE, MULTIPLE PATERNITY AND OFFSPRING SURVIVAL IN LIZARDS

Recent work suggests that rising spring temperatures over recent decades have eliminated many lizard populations, and threaten many more worldwide. However, because ambient temperatures constrain activity times in ectotherms, warming conditions (as expected under global climate change scenarios) can increase the duration of seasonal opportunities for courtship and mating. Thus, in species where polyandry results in enhanced off- spring viability, a warming climate may not necessarily im- pair long-term survival. Our nine-year study of a sand lizard (Lacerta agilis) population near the northern range limit in Sweden revealed consistently higher incidence of multiple pater- nity of clutches in warmer years, and higher viability of offspring from multiply-sired clutches (presumably reflecting the advan- tages of more intense sperm competition). Any trend to warmer spring temperatures likely will benefit offspring viability in this system, by increasing a female’s opportunities to mate with addi- tional males. Many critical ecological traits are highly sensitive to ambient thermal conditions, and hence potentially will be modified by cli- mate change. A growing literature documents such effects on traits such as seasonal phenology, growth rates, and sex-determining systems (Kearney, Porter and Shine 2009; Telemeco, Elphick and Shine 2010). Ectotherms (cold-blooded animals) may be es- pecially vulnerable in such respect, because they are critically dependent upon ambient thermal heterogeneity for behavioral regulation of body temperatures and thus, local climatic condi- tions constrain the timing and intensity of fitness-relevant ac- tivities (Kearney, Porter and Shine 2009). Sinervo et al. (2010) suggest that rising spring temperatures over recent decades have eliminated many lizard populations, and threaten many more worldwide. However, the impact of this thermal shift may be very different in a cold-climate area (such as Sweden) than in a hotter area (such as Mexico, the basis for most of their analyses). In sites where operative temperatures are already close to critical thermal maxima for local reptiles, higher temperatures could be devastating. For example, animals in such an area may have little time per day when conditions are cool enough to allow activities such as mate-searching and foraging (Kearney, Porter and Shine 2009; Sinervo et al. 2010). In contrast, reptiles in cooler areas may benefit from higher temperatures, because the conse- quent ability to maintain relatively high body temperatures over longer periods may enhance organismal fitness via extended ac- tivity times and enhanced performance (Kearney, Porter and Shine 2009). Here we test the hypothesis that warmer weather increases offspring survival via elevated sperm competition (and not just as an effect of higher temperature per se).

Warming climate advances breeding and improves synchrony of food demand and food availability in a boreal passerine

AbstractGlobal climate change affects ecosystems via several trophic levels. We investigated changes in the timing of breeding in the willow tit (Poecile montanus) and timing of its caterpillar food resource in relation to warming springs in a boreal forest. We used generalized linear mixed effect models to study the importance of synchrony between the timing of breeding in willow tits and the caterpillar food availability on the breeding success, measured as nestling survival rate and mean nestling weight. Both the timing of breeding and the timing of the caterpillar peak advanced during the last decades, and were well explained by spring temperatures. Unlike in most passerine populations studied, synchrony has improved with rising spring temperatures. However, it had only a modest although statistically significant positive influence on breeding success. Spring temperatures do not seem to be used as cues for the timing of caterpillar food availability by willow tits. We conclude that responses to climatic warming seem to be population, species and habitat specific, necessitating research in a wide range of taxa in different climatic zones.

Climate‐ and resource‐driven long‐term changes in dormice populations negatively affect hole‐nesting songbirds

AbstractGlobal climate change has been shown to cause variable shifts in phenology in a variety of animals and unexpected outcomes across food chains are to be found. Here we examined how rising annual spring temperatures affected the interactions between seed masting, cavity nesting birds and dormice using long‐term data from Eastern Czech Republic. We have shown that climate change was associated with unequal shifts in the phenology of two cavity‐breeding groups: dormice and birds. Rising spring temperatures have progressively advanced the termination of hibernation for the edible dormouse Glis glis, a common bird predator, leading to an increasing overlap in the use of nesting boxes between dormice and birds. In contrast, only the collared flycatcher Ficedula albicollis, of the four cavity‐nesting bird species, advanced its breeding dates in response to rising temperatures. At the same time, favourable weather conditions, coupled with good seed masting years, have been associated with a substantial rise in dormice numbers. Concurrent with the increasing dormice abundance, the number of bird nests destroyed significantly increased in three out of four bird species. We showed that while there was a significant change in the date that the dormice emerged from hibernation during the course of the study, it did not significantly contribute to predation levels when controlling for their abundance and timing of breeding in birds. We found that the increasing dormice abundance was the main factor causing high brood losses in birds, while the timing of breeding in birds had a variable effect between bird species. This study illustrates how changes in climate might affect organisms at various trophic levels with often unexpected outcomes. Limited evidence from other study organisms suggests that species most at risk are those at different trophic levels that do not shift at the same rate or in the same direction as their food resources, predators or competitors.

Temperature sensitivity of vertical distributions of zooplankton and planktivorous fish in a stratified lake

Recent studies have indicated that temporal mismatches between interacting populations may be caused by consequences of global warming, for example rising spring temperatures. However, little is known about the impact of spatial temperature gradients, their vulnerability to global warming, and their importance for interacting populations. Here, we studied the vertical distribution of two planktivorous fish species (Coregonus spp.) and their zooplankton prey in the deep, oligotrophic Lake Stechlin (Germany). The night-time vertical centre of gravity both of the fish populations and of two of their prey groups, daphnids and copepods, were significantly correlated to the seasonally varying water temperature between March and December 2005. During the warmer months, fish and zooplankton occurred closer to the surface of the lake and experienced higher temperatures. The Coregonus populations differed significantly in their centre of gravity; hence, also, the temperature experienced by the populations was different. Likewise, daphnids and copepods occurred in different water depths and hence experienced different temperatures at least during the summer months. We conclude that any changes in the vertical temperature gradient of the lake as a result of potential future global warming may impact the two fish populations differently, and may shape interaction strength and timing between fish and their zooplankton prey.

Ixodes trianguliceps: seasonal abundance and role in the epidemiology ofBabesia microtiinfection in north-western England

Ixodes trianguliceps is possibly the only species of tick which infests small mammals in the areas studied. The tick has two distinct peaks of activity, in July and October, with somewhat lower infestations in the intervening months; no activity is apparent during the winter. The seasonal activity is triggered by rising spring temperatures which activate the overwintering stages to complete the life cycle. Ixodes trianguliceps is possibly a non-nidicolous species that develops close to the nest of the host; copulation and fertilization may occur on the host.Babesia microti (Knowsley strain) is principally a parasite of microtine rodents and is transmitted in nature through the larval/nymphal instars of Ixodes trianguliceps. The protozoan parasite spends far more time in the vector than in the vertebrate host and is carried over from one season to another in the tick. The occurrence of Babesia microti as a zoonotic infection is discussed.