Disentangling the effects of geographical location and local climate on masting in Fagus crenata using a comprehensive population model

Plant-pollinator interactions are essential for the functioning of terrestrial ecosystems, but are increasingly affected by global change. The risks to such mutualistic interactions from increasing temperature and more frequent extreme climatic events such as drought or advanced snow melt are assumed to depend on network specialization, species richness, local climate and associated parameters such as the amplitude of extreme events. Even though elevational gradients provide valuable model systems for climate change and are accompanied by changes in species richness, responses of plant-pollinator networks to climatic extreme events under different environmental and biotic conditions are currently unknown. Here, we show that elevational climatic gradients, species richness and experimentally simulated extreme events interactively change the structure of mutualistic networks in alpine grasslands. We found that the degree of specialization in plant-pollinator networks (H2') decreased with elevation. Nonetheless, network specialization increased after advanced snow melt at high elevations, whereas changes in network specialization after drought were most pronounced at sites with low species richness. Thus, changes in network specialization after extreme climatic events depended on climatic context and were buffered by high species richness. In our experiment, only generalized plant-pollinator networks changed in their degree of specialization after climatic extreme events. This indicates that contrary to our assumptions, network generalization may not always foster stability of mutualistic interaction networks.

<p>Tropical forests play a critical role in maintaining the balance of biophysical surface fluxes and strongly influence the local and regional climate. Tropical deforestation is therefore increasingly recognised as an issue of global importance as the environmental and climatic consequences of prolific land-cover changes are beginning to be better understood. Using remotely sensed atmospheric and land-surface datasets from 2000 to 2016, climate impacts of deforestation were analysed over three tropical forest domains; the Amazon basin, the Congo basin and South-East Asia (SEA). Trends in local climate responses were observed with increasing deforestation across all tropical regions. Climate analysis was conducted on co-located pixels to ensure geographical differences were accounted for. Land that was deforested over the analysis period showed a decrease in evapotranspiration (ET) and leaf area index (LAI) and a significant increase in daytime land surface temperature (T). Whilst the Amazon saw the greatest relative decrease in LAI (0.2 m<sup>2</sup>/ m<sup>2</sup>), SEA showed the largest decrease in ET (1.5 mm/month) over the period. The climate response in Africa to deforestation is muted, with T increases of only 0.1◦C compared with 0.18◦C and 0.4◦C for SEA and the Amazon respectively. In all regions the response of precipitation was not significant. Increasing temperatures will heighten ecosystem stress for the remaining vegetation and forest adjacent to regions of deforestation will be more susceptible further degradation. The results of this study highlight the differences in climate responses between the tropical regions and the need to consider each separately when conducting future analysis.</p>

We explored the temporal and spatial variations in airborne Alternaria spore quantitative and phenological features in Europe using 23 sites with annual time series between 3 and 15 years. The study covers seven countries and four of the main biogeographical regions in Europe. The observations were obtained with Hirst-type spore traps providing time series with daily records. Site locations extend from Spain in the south to Denmark in the north and from England in the West to Poland in the East. The study is therefore the largest assessment ever carried out for Europe concerning Alternaria. Aerobiological data were investigated for temporal and spatial patterns in their start and peak season dates and their spore indices. Moreover, the effects of climate were checked using meteorological data for the same period, using a crop growth model. We found that local climate, vegetation patterns and management of landscape are governing parameters for the overall spore concentration, while the annual variations caused by weather are of secondary importance but should not be neglected. The start of the Alternaria spore season varies by several months in Europe, but the peak of the season is more synchronised in central-northern Europe in the middle of the summer, while many southern sites have peak dates either earlier or later than northern Europe. The use of a crop growth model to explain the start and peak of season suggests that such methods could be useful to describe Alternaria seasonality in areas with no available observations.

The interactive effects of climate change and land use on boreal stream fish communities

Toxoplasma gondii infection in wild omnivorous and carnivorous animals in Central Europe – A brief overview

Collective climate action may be vital for shaping societal-level change and alleviating climate anxiety. We examined how climate movements can utilise social media to promote local public engagement, as the language and social imagery used by climate activists could affect public willingness to engage. Collaborating with Extinction Rebellion (XR)-United Kingdom (UK), we conducted a randomised controlled field trial with over 350,000 Facebook users in three cities: Birmingham, Oxford, and Cardiff. We evaluated the impact of messaging and imagery on engagement with information about climate events by comparing willingness to click links to attend local climate talks based on requests versus exhortations, alongside protest, impact, and diversity images. We found that exhortations were more effective than requests, especially when paired with climate impact imagery. Message effectiveness varied across cities, being the strongest in Birmingham and weakest in Cardiff, indicating the importance of tailoring strategies to local contexts.

Understanding the role of feedback structure (endogenous processes) and exogenous (climatic and environmental) factors in shaping the dynamics of natural populations is a central challenge within the field of population ecology. We attempted to explain the numerical fluctuations of two sympatric rodent species in agro‐ecosystems of central Argentina using Royama's theoretical framework for analyzing the dynamics of populations influenced by exogenous climatic forces. We found that both rodent species show a first‐order negative feedback structure, suggesting that these populations are regulated by intra‐specific competition (limited by food, space, or enemy‐free space). In Akodon azarae endogenous structure seems to be very strongly influenced by human land‐use represented by annual minimum normalized difference vegetation index (NDVI), with spring and summer rainfall having little influence upon carrying capacity. Calomys venustus’ population dynamics, on the other hand, seem to be more affected by local climate, also with spring and summer rainfall influencing the carrying capacity of the environment, but combined with spring mean temperature.

Latitudinal and climate effects on key plant traits in Chinese forest ecosystems

Weather variables can influence life-history traits of ungulates. In this study, we assessed the suitability of regional climate indices including the NAO and two measures of local climate-the maximal extent of ice on the Baltic Sea (MIE) and absolute values of its annual deviations from the multi-year mean (VMIE)-to examine how density-independent processes influence moose body size and fecundity. We predicted that both winter severity (large values of MIE) and variability (large values of VMIE) depress moose traits (e.g., severe winters increase energy expenditure because of large snow depth or low temperatures, while the warmer than average winters may impose greater energetic demands on thermoregulation due to wet and windy weather, or may have indirect negative effects on summer foraging conditions). We estimated direct, delayed (lag) and cumulative effects of each climate measure. Both MIE and VMIE negatively affected jawbone length, with the effect size varying between the respective climatic indices and among age classes. In contrast to results obtained using local climatic variables, the NAO index had no significant effect on jawbone length. The probability of multiple ovulation was negatively influenced by direct effects of VMIE and delayed effects of MIE and NAO. We conclude that MIE and VMIE capture different aspects of the local climate and that these indices can be used in parallel as determinants of growth and fecundity of northern ungulates in coastal regions of the Baltic Sea.

BOTH the marine sediment record and numerical modelling of the atmospheric summer circulation over the northern Indian Ocean and southeast Asia have shown that the monsoonal climate exhibits a direct but nonlinear response to the intensity of solar insolation during summer, with a time lag of several thousand years1,2. Here we present evidence from a high-resolution record of oxygen isotopes and carbonate spanning the past 24,000 calendar years that the response of the southwest monsoon over the Arabian Sea to long-term, gradual insolation changes occurred in several distinct events of less than 300 years duration, at 14,300, 13,500, 13,060, 9,900, 8,800 and 7,30014C yr BP. Thus, during this transitional period from glacial to post-glacial conditions the slow solar forcing seems to have induced very rapid changes in local climate. We speculate that the rapid response may be related to albedo changes in Asia.

A nutrient-transfer model to explain the fate of phosphorus and sulphur in a Grazed Hill-Country pasture

Global climate patterns are shifting due to anthropogenic causes, putting pressure on many species that are unable to adapt to such rapid changes. Sea turtle clutches, for example, normally develop between 26 and 33°C, but tolerate higher temperatures at the end of development. High temperatures, protracted rainfall, and droughts have been linked to fewer hatchlings. Likewise, climatic conditions can affect the size of sea turtle hatchlings, which could affect their probability of survival. We analyzed the effects of a biotic factor (egg mass) and environmental factors (precipitation and incubation temperature) on East Pacific leatherback turtle Dermochelys coriacea hatchling sizes in Costa Rica. Hatchling size (mass, straight carapace length, straight carapace width, and head width) was affected by both biotic and environmental factors. While egg mass was the strongest predictor for hatchling mass, temperature was the strongest for carapace length and head width. Carapace width was most strongly predicted by precipitation. Hatchling carapace length and width decreased with increases in temperature and increased with higher levels of precipitation. Hatchling mass also decreased with increasing temperature, although the relationship was not statistically significant. Head width decreased with greater precipitation during development. These findings suggest that increases in temperature and decreases in precipitation may not only decrease the number of hatchlings produced, but may also produce smaller leatherback hatchlings in Pacific Costa Rica, which may impair hatchling survival in the first hours after emergence.

Great deficiency of meteorological data seems to be one of its main features from the viewpoint of climate dynamics estimations. The deficiency is caused by non-renewable losses in past together with slow gathering in present. So, here we discuss one of the way how to use the available observations of land surface air temperature in order to get estimations on evolution of local climate dynamics. Since such dynamics is characterized by too high variety of nonlinear behaviors, then the bifurcation analysis remains the main tool to provide reasonable and impartial results concerning evolutional processes. In this context, we develop the approach to model-based reconstruction of the dynamics on the basis of so-called HDS-model (the model of a Hysteresis regulator with Double Synchronization). At present, only this conceptual model allows to describe the cause-and-effect relations between hysteresis phenomena and feed backs in a local space scale from the bifurcation analysis viewpoint. The idea of the research consists in the attempt to use the HDS-model in order to reconstruct nonlinear dynamics tendencies concerning the most actual fundamental points at least. In particular, we demonstrate the novel abilities concerning how to reveal constituents of latent evolutional processes which can not be recognized by other ways. We believe that the presented discussion could help to pay attention on local peculiarities of inevitable climate changes, and, after, could help to assess impartially climate and economic effects caused by such changes, especially, in relation to a point of no return.

Abstract. Directly linking greenhouse gas emissions or global warming to experiences of local climatic changes is a potentially important communication tool. Using observations, we develop a physically plausible “causal chain” visualisation to demonstrate the connections between global carbon dioxide emissions and local climate events. We highlight how increased flood risk in one river basin in the UK could be discussed with people directly affected by recent floods.

The effect of urbanization on local climate is quantified by numerical simulations for five desert cities that represent a wide range of urban size, climate zone, and composition of land cover. Land-use land cover maps generated from Landsat data for 1985 and 2010, chosen as the start and end of a period of rapid urbanization, are used to constrain the surface boundary conditions for the numerical model. In this manner, this study focuses on the particular aspect of the effect of land-use changes on local climate. Within this scope, the results reveal a pattern of the climatic effect of desert urbanization with nighttime warming and weaker, but significant daytime cooling. This effect is confined to the urban area and is not sensitive to the size of the city or the detailed land cover types in the surrounding areas. The pattern is identified in both winter and summer. Exceptions to this pattern are found in a small number of cases when the noisiness of local circulation, specifically monsoon and land–sea breeze, overwhelms the climatic signal induced by land-use changes. The inter-cities’ differences in the temperature response to land-use change are also discussed.