Potential Effects Of Global Warming Research Articles

Climatological features of future MCSs over the Canadian Prairies using convection-permitting climate models

This study explores the potential effects of global warming on Mesoscale Convective Systems (MCSs) initiation and duration in the Canadian Prairies. By utilizing high-resolution convection-permitting climate models (CPCMs), the study examines 15 parameters to identify the most significant factor for predicting future changes, using the Pseudo Global Warming (PGW) approach. The results suggest that the frequency of MCSs will significantly increase in the future, with varying initiation and duration patterns between daytime and nighttime. The study highlights Preciptable Water (PW), Isentropic Potential Vorticity (IPV), and Most Unstable Convective Potential Energy (MUCAPE) as the most significant parameters for long-lived nighttime MCSs, while Relative Humidity at 850 hPa (RH850), PW, and Storm Relative Helicity 0-1 km (SRH1km) are identified as the most significant parameters for long-lived daytime MCSs. The findings are supported by violin plots that show the differences in the distribution of the 15 parameters in the initiation regions of short- and long-lived MCSs. Additionally, this study partially confirms previous research findings, such as the Mountain-plains solenoids, which suggest that increased PW and RH850 in the future are in agreement with increased total precipitation in the northern region. The study emphasizes the importance of utilizing newly released forcing datasets to investigate the potential impact of global warming on MCSs initiation and duration in the Canadian Prairies.

Malaria metrics distribution under global warming: assessment of the VECTRI malaria model over Cameroon.

Malaria is a critical health issue across the world and especially in Africa. Studies based on dynamical models helped to understand inter-linkages between this illness and climate. In this study, we evaluated the ability of the VECTRI community vector malaria model to simulate the spread of malaria in Cameroon using rainfall and temperature data from FEWS-ARC2 and ERA-interim, respectively. In addition, we simulated the model using five results of the dynamical downscaling of the regional climate model RCA4 within two time frames named near future (2035-2065) and far future (2071-2100), aiming to explore the potential effects of global warming on the malaria propagation over Cameroon. The evaluated metrics include the risk maps of the entomological inoculation rate (EIR) and the parasite ratio (PR). During the historical period (1985-2005), the model satisfactorily reproduces the observed PR and EIR. Results of projections reveal that under global warming, heterogeneous changes feature the study area, with localized increases or decreases in PR and EIR. As the level of radiative forcing increases (from 2.6 to 8.5W.m-2), the magnitude of change in PR and EIR also gradually intensifies. The occurrence of transmission peaks is projected in the temperature range of 26-28°C. Moreover, PR and EIR vary depending on the three agro-climatic regions of the study area. VECTRI still needs to integrate other aspects of disease transmission, such as population mobility and intervention strategies, in order to be more relevant to support actions of decision-makers and policy makers.

Drought Effects in Somalia and Solution Proposals

Drought is a natural climatic phenomenon that occurs when rainfall is less than average for an extended period of time. It can occur at any time and in any location. Droughts are extremely difficult to predict at the start and end. It happens quietly, and the consequences can last for years after the event is over. Drought is a natural occurrence with economic, environmental, and social implications. Drought is characterised by a prolonged lack of precipitation that results in significant water scarcity in a region. Drought usually begins in agriculture and then spreads to other water-dependent industries. Due to its geographical location, fragile environment, volatile climate, political instability in the country, and the potential effects of global warming, Somalia is vulnerable to drought. Reducing the negative effects of drought is possible if precautions are taken prior to the drought and proper planning is made during the drought period. As a result, the measures to be taken before the drought and the steps that can be taken during the drought should be planned separately. Although we cannot increase water supply by ensuring the continuity of precipitation, we can mitigate the negative effects of drought.

Differential expression profiling of heat stressed tardigrades reveals major shift in the transcriptome

Tardigrades are renowned for their extreme stress tolerance, which includes the ability to endure complete desiccation, high levels of radiation and very low sub-zero temperatures. Nevertheless, tardigrades appear to be vulnerable to high temperatures and thus the potential effects of global warming. Here, we provide the first analysis of transcriptome data obtained from heat stressed specimens of the eutardigrade Ramazzottius varieornatus, with the aim of providing new insights into the molecular processes affected by high temperatures. Specifically, we compare RNA-seq datasets obtained from active, heat-exposed (35 °C) tardigrades to that of active controls kept at 5 °C. Our data reveal a surprising shift in transcription, involving 9634 differentially expressed transcripts, corresponding to >35% of the transcriptome. The latter data are in striking contrast to the hitherto observed constitutive expression underlying tardigrade extreme stress tolerance and entrance into the latent state of life, known as cryptobiosis. Thus, when examining the molecular response, heat-stress appears to be more stressful for R. varieornatus than extreme conditions, such as desiccation or freezing. A gene ontology analysis reveals that the heat stress response involves a change in transcription and presumably translation, including an adjustment of metabolism, and, putatively, preparation for encystment and subsequent diapause. Among the differentially expressed transcripts we find heat-shock proteins as well as the eutardigrade specific proteins (CAHS, SAHS, MAHS, RvLEAM, and Dsup). The latter proteins thus seem to contribute to a general stress response, and may not be directly related to cryptobiosis.

An Introduction to ‘Peace, Conflicts and Security in the Anthropocene: Ruptures and Limits’

Throughout the last two decades, numerous disciplines across the natural and social sciences have witnessed the increasing influence of an emerging set of contemporary theoretical trends that delve into the entanglements between the human and its material milieu (see Haraway, 2016; Latour, 2005). Beyond rigid attributed labels, including new materialisms, Actor-Network theory, speculative realisms and object-oriented ontology, amongst others, the genealogy of these theoretical movements arguably traces back to the confluence of two mutually reinforcing processes. On the one hand, the current unprecedented techno-scientific progress in areas such as Earth System Sciences and Science and Technology Studies has led to compelling narratives on unsettling events, including the potential effects of global warming as well as the uncertain future implications of developments in fields as, for instance, Artificial Intelligence. As a result of these challenges and speculations, the hypothetical finitude of the human being on the planet, far from abstract apocalyptic discourses, has become a strikingly perceptible experience. In other words, the stories about the distinctive, superior and masterful character of the human on Earth increasingly seem to fade, and its future seems unquestionably inextricable from broader beyond-the-human phenomena (see Tsing, 2015). The present age in which the human has compromised its own existence, or at least its position of dominance, to anthropogenic processes that surpass the sphere of human control has been defined by many scholars as the Anthropocene (see Crutzen & Stoermer, 2000). On the other hand, the tenets of this growing theoretical rubric claim the exhaustion and incapacity of the post-positivist paradigm, arguably the dominant register within critical theory over the last forty years, as unable to provide analytical tools that enhance the comprehensive understanding of the repositioning of the human in the Anthropocene era (see Bryant, Srnicek & Harman, 2011). To be precise, the limits of textual, discursive and semiotic methodological techniques are exposed as insufficient to capture and examine how Anthropocenic processes of transformation are reconfiguring the role of the human on the planet, let alone the relations with its environment.

Size‐, species‐, and site‐specific tree growth responses to climate variability in old‐growth subalpine forests

AbstractTree‐ring data have become widely used to model tree growth responses to climate variability and gain insight about the potential effects of global warming on forests. We capitalized on a rare opportunity to develop growth–climate models using tree‐ring data collected from all trees (>4 cm in diameter at breast height) within 50 × 50 m plots established in subalpine old‐growth forests of western Canada. Our objective was to determine how tree growth responses to climate vary among tree size classes, species, and sites. We modeled relationships between times series of annual basal area increment (ΔBA) and yearly climate variables for individual trees; this approach obviated key statistical criticisms of “traditional” tree‐ring analysis methods. Time series of annual basal area increment were detrended a priori for size, age, legacy, and competition effects. We found that the overall climate signal in our time series of ΔBA was weak; <6% of the interannual variance was explained by climate variables. Nevertheless, there were clear patterns in climate–growth relationships related to tree size and species. Relationships between ΔBA and five climate variables increased in strength with tree size class; large trees were most sensitive to annual climate fluctuations and accounted for ~71% of the overall climate effect on growth across all trees and sites. In all stands, ΔBA variance explained by climate variables was stable over the 20th century for large trees but decreased in the 1940s for small trees, indicating a temporal reduction in sensitivity to annual fluctuations in five climate variables. In coastal forests, relationships between ΔBA and climate for Callitropsis nootkatensis were significantly different in direction and magnitude than those of co‐occurring Pinaceae species. The effect of climate on tree growth was idiosyncratic among stands and could not be discriminated by forest type (coastal vs. interior). Our individual‐tree modeling approach adds to a growing body of research providing novel insights about the complexities of tree growth responses to climate variability and the challenges associated with predicting future tree growth and forest productivity using tree‐ring data.

The end of primary moult as an indicator of global warming effects in the Red-legged Partridge Alectoris rufa, a medium sized, sedentary species

Global warming affects ecosystem services, communities and populations, influencing the physiology, behaviour or environment of living beings, and hence impacts its survival or breeding. Identifying species susceptibility to warming is relevant in assessing risks to animal populations and ecological processes. The progressive increase in ambient temperature as a result of global warming might have an effect on the timing of primary moult. This could affect a bird’s annual cycle, influencing reproductive success and population dynamics.We describe a method to examine the potential effects of global warming on the primary moult process in a sedentary population of Red-legged Partridges (Alectoris rufa). We organised the factors that might influence the timing of moult end into a network and distinguished between environmental and intrinsic factors. We sorted the factors according to their contribution to quantitative moult models and constructed a diagrammatic scheme showing their interactions and effect on the end of primary moult over the annual cycle.In Red-legged Partridges, the timing of the end of moult varies according to age-sex class. We found no timing differences by age, but found significant timing differences by adult sex. More females overlap their moult with juveniles than males because female parental effort is higher, more females incubate and brood chicks. The timing of the end of moult varies by year due to conspecific interactions that change according to influences of the weather, habitat, and social and flock conditions. Parent birds synchronize their primary moult with the chick's growth, degree of cover and food resources. From the time of hatching to the following year, the date (day-length), social factors (conspecific interactions), and weather (resources) affect the timing of moult and the birds’ annual cycle.Global warming affects the timing of the end of moult and that of the annual cycle. If the extent of the breeding period is shortened, there could be a negative effect on population outcomes. Middle size prey species are key in trophic chains. Our results suggest that the timing of the end of moult could be used as a proxy measure of warming impacts on wildlife and ecosystems and also as a tool for the management of game birds.

Demographic Crises of Different Climate Phases in Preindustrial Northern Hemisphere

This research empirically analyzes the association between climate change, population size, and demographic crises as indicated by what we term “population checks,” or major wars, epidemics, and famines from AD 1000 to AD 1900 in the Northern Hemisphere based on historical records and climate reconstructions. We conducted this study at two temporal scales: (1) the entire study period of 900 years and (2) three climate phases according to temperature (cold, mild, and warm) of 300 years each. By adopting linear and nonlinear statistical methods, we found climate change and population size to have significant roles in driving the demographic crisis at the temporal scale of the entire study period. In terms of the three climate phases of 300 years each, we find that war is more closely correlated to climate change than to population size for all three phases. However, population size itself is more likely to trigger epidemics during mild and warm phases and is more important in relation to famines than climate change during all three climate phases. This study emphasizes the importance of scale in reviewing the social past in terms of climate change and population size. Empirical evidence of large-scale demographic crises within the three climate phases could also provide a timely reference for scientists or policymakers in addressing the potential effects of global warming.

Thermal performance across levels of biological organization.

Thermal performance curves are widely used to describe how ambient temperature impacts different attributes of ectothermic organisms, from protein function to life-history traits, and to predict the potential effects of global warming on ecological systems. Nonetheless, from an analytical standpoint, they remain primarily heuristic and few attempts have been made to develop a formal framework to characterize these curves and disentangle which factors contribute to their variation. Here we employ a nonlinear regression approach to assess if they vary systematically in shape depending on the performance proxy of choice. We compare curves at contrasting levels of organization, namely photosynthetic rates in plants ( n = 43), running speeds in lizards ( n = 51) and intrinsic rates of population increase in insects ( n = 47), and show with discriminant analyses that differences lie in a single dimension accounting for 99.1% of the variation, resulting in 75.8% of classification accuracy. Differences revolve primarily around the thermal range for elevated performance (greater than or equal to 50% of maximum performance), which is broader for photosynthetic rates (median of 26.4°C), intermediate for running speeds (19.5°C) and narrower for intrinsic rates of increase (12.5°C). We contend, confounding taxonomic factors aside, that these differences reflect contrasting levels of biological organization, and hypothesize that the thermal range for elevated performance should decrease at higher organization levels. In this scenario, instantaneous or short-term measures of performance may grossly overestimate the thermal safety margins for population growth and reproduction. Taken together, our analyses suggest that descriptors of the curve are highly correlated and respond in tandem, potentially resulting in systematic variation in shape across organization levels. Future studies should take into consideration this potential bias, address if it constitutes a general pattern and, if so, explain why and how it emerges. This article is part of the theme issue 'Physiological diversity, biodiversity patterns and global climate change: testing key hypotheses involving temperature and oxygen'.

A shift in reptile diversity and abundance over the last 25 years

The south-facing slopes in canyons, oriented along an east-west axis north of the equator, are often hotter and drier than north-facing slopes, promoting differences in the biotic and abiotic characteristics of the opposing slopes. We studied how diversity and abundance patterns have changed in Oren stream (Carmel Mountains, Israel) during the last 25 years. We tested whether temperature and habitat preferences of reptiles affected observation frequencies, to assess potential effects of global warming on the reptiles. We compared the results of a 1993–1994 survey in Oren stream to a survey we conducted during 2017–2018, using similar methods, survey area and effort. Species composition and abundance in Oren stream did not significantly change between studies, but the proportion of observations differed significantly across slopes for four out of the six most abundant species. The number of observations increased monotonically with increasing temperatures on the south-facing slope, but decreased on the north-facing slope above a temperature of 22°C. The major biome species inhabit globally was unrelated to the number of observations across slopes or studies, but species inhabiting warmer ranges were more frequently observed in the current survey. Our results suggest that as global temperatures rise, reptile species which can tolerate higher temperatures, and those which can avoid the hottest temperatures of the day, may be able to cope better. These results however may also derive from better detection ability of some species over others between study teams.

Experimental warming reduced topsoil carbon content and increased soil bacterial diversity in a subtropical planted forest

The potential effects of global warming on the soil carbon (C) dynamics of subtropical forests are uncertain. To assess the effects of warming on soil C and tree roots, combined soil warming (infrared heaters, +1.5 °C soil temperature) and trenching experiments were conducted in a subtropical Castanopsis hystrix plantation. Topsoil C content was reassessed after five years of warming, and the effects on soil organic carbon (SOC) quality and microbial diversity were analyzed. Compared with corresponding controls, the topsoil (0–10 cm) SOC content was significantly lower in un-trenched warmed soil (−13.6%) as well as in trenched warmed soil (−15.4%). However, the range of SOC content after five years of warming was similar to that observed after two years of warming (−14.6%, −19.2%), indicating that the warming effect on SOC content had leveled off during the latter three years of the study. In trenched plots, warming significantly decreased the carbohydrate C as well as the ratio of carbohydrate C to N-alkyl/methoxyl C (CC/MC), suggesting that labile C was preferentially decomposed. In un-trenched plots, SOC quality was unaffected, indicating a compensatory input of labile root C. Bacterial α-diversity increased under warming, whereas no significant warming effects on fungal community diversity were observed. Both the SOC content and the proportion of soil carbohydrate C were negatively correlated with soil bacterial α-diversity, suggesting that the abundance of more recalcitrant SOC increased soil microbial diversity. Overall, our study indicates that soil warming leads to moderate initial reductions in topsoil SOC in the studied forest ecosystem. This is consistent with recent evidence that low SOC-containing soils (e.g., subtropical forest soils) exhibit a weaker response to soil warming than high SOC-containing soils.

An approach to global warming effects on flowering and fruit set of olive trees growing under field conditions

Abstract The increase in air temperature associated to climate change is expected to affect olive (Olea europaea L.) tree fructification. To determine the potential effects of global warming on floral phenology and fruit set under field conditions, olive trees growing in a Mediterranean climate type area were subjected to warmer temperature than ambient by the use of temperature controlled Open-top-Chambers (OTCs). Each OTC, equipped with heating and ventilation devices, was able to maintain a day/night temperature gradient between the tree and the surrounding environment of 4 °C throughout the complete reproductive cycle of this species. After three years of study, the results obtained have shown that increasing temperature 4 °C above the actual ambient temperature may led to an advance of the date of flowering in the olive, an extent of the flowering period, an increase of pistil abortion, and a reduction in fruit set, conditions which may reduce yield.

Developmental temperature has persistent, sexually dimorphic effects on zebrafish cardiac anatomy

Over the next century, climate change of anthropogenic origin is a major threat to global biodiversity. We show here that developmental temperature can have significant effects on zebrafish cardiac anatomy and swimming performance. Zebrafish embryos were subjected to three developmental temperature treatments (TD = 24, 28 or 32 °C) up to metamorphosis and then all maintained under common conditions (28 °C) to adulthood. We found that developmental temperature affected cardiac anatomy of juveniles and adults even eight months after the different thermal treatments had been applied. The elevation of TD induced a significant increase of the ventricle roundness in juvenile (10% increase) and male (22% increase), but not in female zebrafish. The aerobic exercise performance of adult zebrafish was significantly decreased as TD elevated from 24 to 32 °C. Gene expression analysis that was performed at the end of the temperature treatments revealed significant up-regulation of nppa, myh7 and mybpc3 genes at the colder temperature. Our work provides the first evidence for a direct link between developmental temperature and cardiac form at later life-stages. Our results also add to the emerging rationale for understanding the potential effects of global warming on how fish will perform in their natural environment.

Allis shad adopts an efficient spawning tactic to optimise offspring survival

The potential effects of global warming on the allis shad population were tested by combining a time series of spawning acts with expected thermal survival rates for embryos and larvae until 14 days post hatching. The yearly mean survival of spawn for each reproductive season was calculated and an index of reproductive efficiency based on this survival rate was proposed. The randomness of the spawning tactics was evaluated by shuffling the spawn acts time series. This approach was applied to the Gironde-Garonne-Dordogne (south-west France) population, which recently collapsed. The yearly mean thermal survival of spawn is slightly variable at approximately 55% over 2003–2012 despite fluctuating temperatures. An especially low survival (35%) was recorded for the last season (2013). For eight of the 11 reproductive seasons, the index of reproductive efficiency was high (> 80%) and largely above indices obtained by a random spawning tactic. Therefore shad are able to adopt an efficient spawning tactic to anticipate favourable thermal conditions for survival of their offspring. However, thermal behavioural rules still need to be expanded to understand the failures in their reproduction efficiency.

Potential Effects of Global Warming on Quail Populations

Potential Effects of Global Warming on Quail Populations

Does Water Temperature Affect the Timing and Duration of Remigial Moult in Sea Ducks? An Experimental Approach.

Aquatic birds have high cost of thermoregulation, especially during the moulting period, yet the effect of water temperature on the moulting strategy of aquatic birds has rarely been studied. Our general hypothesis is that energy savings associated with lower thermoregulation costs would be allocated to moulting processes. We predicted that aquatic birds moulting in warm water would have a higher level of body reserves, a faster growth rate of feathers, and an earlier remigial moult onset compared with birds moulting in cold water. We used the common eider (Somateria mollissima dresseri), a large sea duck, as the model species. Captive individuals were experimentally exposed to warm (18°C) and cold (8°C) water treatments during a three year period with individuals swapped between treatments. We found a similar feather growth rate for the two water temperature treatments and in contrast to our predictions, eiders exposed to warm water had a lower body mass and showed a delayed onset of remigial moult of approximately 7 days compared with those exposed to cold water. Our data indicate that body mass variations influence the timing of moult in unexpected ways and we suggest that it likely controls the occurrence of wing moult through a hormonal cascade. This study emphasizes the importance of improving our knowledge of the effects of water temperature on remigial moult of aquatic birds, to better assert the potential effects of global warming on their survival.

哀牢山亚热带常绿阔叶林森林土壤温湿特征及其对温度升高的响应

PDF HTML阅读 XML下载 导出引用 引用提醒 哀牢山亚热带常绿阔叶林森林土壤温湿特征及其对温度升高的响应 DOI: 10.5846/stxb201403260562 作者: 作者单位: 中国科学院热带森林生态学重点实验室,中国科学院哀牢山生态站;中国科学院哀牢山生态站,日本国立环境研究所,日本,筑波,-,;日本国立环境研究所,日本,筑波,-,中国科学院热带森林生态学重点实验室,中国科学院哀牢山生态站;中国科学院哀牢山生态站,中国科学院热带森林生态学重点实验室 作者简介: 通讯作者: 中图分类号: 基金项目: 云南省自然科学基金重点项目(2011FA025);国家基金-云南省联合项目(U1202234); 国家基金重大项目(31290220); 中国科学院战略性专项项目(XDA05050601, XDA05050206) Responses of soil temperature, moisture and respiration to experimental warming in a subtropical evergreen broad-leaved forest in Ailao Mountains, Yunnan Author: Affiliation: Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences,,,,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为把握土壤温度对未来全球气候变暖的响应程度,评估气候变暖对亚热带森林土壤呼吸的影响,利用在哀牢山亚热带常绿阔叶林中设置的土壤增温和土壤呼吸人工控制实验2011-2013年的实测数据,通过分析,得到如下结果:环境温度的升高不会改变林内的近地层气温、土壤温度和土壤含水量的年变化和日变化规律;冬季和夜间增温效应大于夏季和昼间;增温会导致土壤含水量降低,雨季的效应大于干季;增温导致的升温效应和降低土壤水分效应具有一定的年变化,但是基本没有日变化;所设置的人工增温控制实验的年平均增温在2.0 ℃左右,所设置人工控制实验可以达到5 cm土壤增温2.0 ℃的设计要求,可为其后探讨土壤呼吸对温度升高的响应提供良好的基础保证. Abstract:The soil-surface carbon flux is comparable to that of photosynthesis in terrestrial ecosystems. Much soil carbon flux to the atmosphere is due to rhizosphere metabolism (root respiration) and the decomposition of soil microbes (microbial respiration), which are both very sensitive to temperature. With soil temperatures increasing, soil respiration will increase, thereby accelerating global change. To improve our understanding of the response of soil temperature to future warming and to assess the potential effects of global warming on soil respiration in subtropical forests, we experimentally warmed subtropical evergreen broad-leaved forest soils in Ailao Mountain Southwest, China and measured their respiration. This experiment was conducted at the Ailaoshan Station for Subtropical Forest Ecosystem Studies (24°32'N, 101°01'E; 2480 m above sea level) of the Chinese Ecological Research Network, Jingdong County, Yunnan Province. The annual mean air temperature was 11.0℃, with a maximum monthly mean temperature of 15.3℃ in July and a minimum monthly mean temperature of 5.1℃ in January. The site has strong rainy seasons (May to October) and dry seasons (November to April the following year). The average annual rainfall was 1882 mm, with 1607 mm (85.4% of the annual total) in the rainy season and 274.2 mm in the dry season (14.6% of the annual total). The soil is yellow brown in this area. Litterfall accumulates to 3-7 cm. Soil humus is dark brown and 10-15 cm thick. The mineral soil layer is loose and dominated by soil aggregates. Surface soils have high water permeability and water conservation ability, high organic carbon, and a pH of 4.5-5. Our artificial warming experiment was conducted in a subtropical forest where wind speed and radiation are both low at the surface. A multi-channel automated chamber system was used to continuously monitor soil CO2 effluxes. The system was comprised of 20 automatic chambers (length 90 cm × width 90 cm × height 50 cm) and a control box, and the 20 chambers were divided into 4 treatments (5 chambers per treatment): control, litter removal, trenching, and infrared light warming. The soil efflux of each chamber was measured automatically each hour and environmental factors were measured each half hour. When measuring soil efflux, the chamber was closed for 3 min, then opened for 57 min by opening its lid. Thus, environmental conditions (e.g., wind, rainfall, and litterfall) in chambers were similar to those outside. In the artificial warming experiment, variations in soil temperature and soil water content were observed along with soil respiration. Based on measurements from 2011 to 2013, we concluded that warming did not change the seasonal and diurnal patterns of air temperature near the soil surface, soil temperature, or soil water content of the forest. The warming effects in winter and nighttime were greater than in summer and daytime. Warming decreased soil water content to a larger extent in the rainy season than in the dry season. The temperature increase and soil water decrease resulting from warming had seasonal variations, but not diurnal variations. The experimental warming increased the annual soil temperature by about 2℃; therefore, the warming treatment reached the goal of increasing soil temperature at 5 cm by 2℃. Our infrared warming method achieved a relatively stable warming effect without time lags in soil-temperature variations in the primary subtropical evergreen broad-leaved forest in Ailao Mountain. In this subtropical evergreen broad-leaved forest, soil temperature has previously shown a significant warming trend, so this study can supply information about soil respiration responses. This study also showed that variation in local air temperature, soil temperature, and soil-water content will not change under global warming, but soil-water content will decline with increased temperature, especially in the rainy season. In the forest, soil respiration is affected not only by soil temperature, but also by soil water content. As warming decreases soil water content, the effects of soil water content variation on soil respiration should be examined in future research. 参考文献 相似文献 引证文献

Geographical distribution, climatic variability and thermo‐tolerance of Chagas disease vectors

Understanding the relationship between geographic range limits and physiological traits of vector species is under increasing demand to predict the potential effects of global warming, not only in terms of geographic distribution of vector species but also in terms of the risk of disease transmission. Like in many other insect species, the geographical distribution of Chagas’ disease vectors is affected by temperature. This study examines, for the first time, the relationship between the limits of geographic distribution and thermo‐tolerance of the most important vectors of Chagas disease, Triatoma infestans in southern South America and Rhodnius prolixus in northern South America and Central America, to test the climatic variability hypothesis (CVH). We applied species distribution modeling (SDM) using bioclimatic variables and identified the most important limiting factors of the habitat suitability. Then, we measured and compared: the critical thermal maximum (CTmax) and the upper lethal temperature (ULT) (measured by thermo‐limit respirometry), chilled coma recovery (i.e. the time to recovery from 4 h at 0°C) and the critical thermal minimum (CTmin). For both species the minimum temperature of the coldest month was the most important abiotic factor restricting their geographic distribution. By taking a correlative approach and testing predictions with thermal tolerance traits, it was possible to explain the southern limit distribution for both species in terms of physiological constraints. The greater temperature tolerance of T. infestans compared to R. prolixus supports the CVH.

Spring barley (Hordeum vulgare L.) Responses to Soil Injected Liquid Ammonium Nutrition under Different Growth Temperatures

Controlled chamber experiments were performed at Braunschweig, Germany to examine the potential effects of global warming on spring barley (Hordeum vulgare L.) shoot and root biomass accumulation, yield forming structures (tillers) and attainable grain yield through the adoption of a novel fertilization technique that injects liquid ammonium nutrition into soil for crop uptake. Three growth temperature regimes; low (Temperate), medium (Intermediate) and high (Tropical) were set to mimic different climatic conditions experienced globally. Each temperature regime comprised of three nitrogen fertilization treatments of which conventional nitrate application and non-fertilized control were compared to soil injected liquid ammonium nutrition herein referred to as Controlled Uptake Long Term Ammonium Nutrition (CULTAN). Each of the three nitrogen treatments was replicated twice in each of the three temperature regimes. The experiment was repeated in two seasons during which chamber randomization was performed eliminate chamber effects. Nitrogen fertilized barley attained superior grain yields under low temperature regime (LTR) as compared to high temperature regimes (HTR). Similarly, low temperature regimes supported higher shoot and root biomasses, more tillers and ear bearing tillers than the other two temperature regimes. Grain yields were correlated to ear bearing tillers and grain numbers. Low temperature regime supported more grains that weighed less per grain in comparison to warmer temperatures which compensated for less grain numbers by heavy grains. This is the first time interaction effects between soil injected liquid ammonium nutrition (CULTAN fertilization) and temperature regimes have been reported in a cereal crop production model. The results demonstrate that growth temperatures and nitrogen nutrition forms jointly can cause a suite of responses on barley growth and yield formation with potential for exploitation in enhancement of food security.

Thermotolerance and regeneration in the brittle star species complex Ophioderma longicauda: A preliminary study comparing lineages and Mediterranean basins

Global warming is expected to change marine species distributions; it is thus critical to understand species current thermotolerance. The brittle star species complex Ophioderma longicauda comprises a broadcast spawning lineage L1 and a brooding lineage L3. We collected L1 specimens from Marseilles and Crete, and L3 specimens from Crete. We monitored survival, autotomy and arm regeneration at 17, 26 and 30°C during 14 weeks. Globally O. longicauda showed good resistance to elevated temperatures compared to other published studies on ophiuroids. The L3 sample displayed a better thermotolerance than L1 samples. Yet, more research is needed to establish whether these differences are due to lineages, geographic origin, or random effects. We provided for the first time individual regeneration trajectories, and showed that regeneration followed a growth curve and was highly influenced by temperature in both lineages. Our results highlight the importance of taking into account the presence of cryptic species when studying the potential effects of global warming.