Disentangling the effects of a century of eutrophication and climate warming on freshwater lake fish assemblages

Understanding the effect of climate warming and technological progress on crop production systems is crucial for developing climate adaptation strategies. This study presents a methodological framework with which to assess the suitability of the double rice cropping system in Southern China and the effects of crop management and climate warming on its distribution. The results indicate that the isolated effects of climate warming have led to the northward and westward expansions of double rice northern limits over the past six decades and an increase in suitable areas by 4.76 Mha. Under the isolated effect of crop management, the northern limits of the medium- and late-maturity double rice changed significantly due to the increased accumulated temperature required caused by varietal replacement and planting date change, which moved an average of 123 and 134 km southward, respectively. A combined scenario analysis indicated that crop management could offset the effects of climate warming and push the northern limits southward, reducing the overall suitable area by 1.31 Mha. Varietal replacement and other crop management methods should also be appropriately considered in addition to climate warming to develop locally adapted agricultural management strategies.

Land conversion regulates the effects of long-term climate warming on soil micro-food web communities

Temperature during egg formation and the effect of climate warming on egg size in a small songbird

PDF HTML阅读 XML下载 导出引用 引用提醒 全球气候变暖影响植物-传粉者网络的研究进展 DOI: 10.5846/stxb201309102245 作者: 作者单位: 江西省吉安市青原区学苑路井冈山大学生命科学学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目(31060069, 31360099); 教育部新世纪优秀人才支持计划(NCET-07-0385); 江西省自然科学基金项目(2010GZN0129); 江西省高水平学科(生物学) New advances in effects of global warming on plant-pollinator networks Author: Affiliation: College of Life Sciences, Jinggangshan University，Jiangxi Province 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:植物与传粉者间相互作用,构成了复杂的传粉网络。目前,以气候变化为主要特征的全球变暖对植物-传粉者网络的影响备受关注,概述了近年来这方面研究的几个主要热点问题及其进展,和相关研究方法。并在此基础上,提出了气温持续上升背景下,植物-传粉者网络未来的研究趋势。当前研究的主要热点问题有:(1)气候变暖使植物、传粉者的物候发生变化,并通过影响植物的开花时间和传粉者活动时间,导致两者在物候时间上的不同步。(2)气候变暖导致植物、传粉者的群落结构变化,促使其地理分布向更高纬度和更高海拔扩散,这可能潜在的导致两者空间分布的不匹配。(3)植物和传粉者通过增加或减少其丰富度来响应气候变暖,可能导致传粉网络结构特征发生变化。(4)面对气候变暖导致植物和传粉者间物候和地理分布错配所引发的互作改变、甚至解体,传粉网络可通过自身网络结构及快速进化来缓冲和适应。在今后研究中,以下几个问题值得探讨:1)气候变暖对植物-传粉者网络影响的大时空尺度变异模式。2)多因素协同作用对植物-传粉者网络的影响特征。3)全球气候变暖对植物、传粉者物候匹配性影响的机理。 Abstract:The interactions between plants and pollinators result in complex pollination networks. The effects of global climate warming on plant-pollinator networks have attracted extensive attention at present. In this paper, we attempt to introduce several major advances and some new interests in this area. Furthermore, we discussed the future research trends of plant-pollinator networks based on continuously rising temperature. (1) Climate warming makes phenology shift of plants and pollinators by affecting flowering time of plants and activity time of pollinators, which leads to a temporal decoupling of plants and pollinators. (2) Climate warming may cause changes in community structure of plants and pollinators and thus make them distribute to areas in higher latitude and altitude. These changes may result in spatial mismatch of plants and pollinators. (3) Plants and pollinators response to climate warming by increase or decrease its abundance, which may cause changes in structure of pollination networks. (4) The structure and rapid evolution of pollination networks can adapt to the changes or even collapse of interaction between plants and pollinators that result from the phenological and geographical distribution mismatch caused by climate warming. The following contents should be studied in the further research: (1) The effects of climate warming on plant-pollinator networks at large spatiotemporal scales; (2) The effects of multi-factorial synergy on plant-pollinator networks; (3) The mechanism of phenological matching caused by global warming. 参考文献 相似文献 引证文献

The ongoing global warming tends to reduce Larix decidua radial growth and ring wood density at the bottom of an elevational gradient in the French Alps, while it has a less marked effect at the top. The ongoing climate warming affects most tree species across their biogeographic distribution range. The bottom and the top of an elevational gradient are appropriate environments to observe the effect of climate warming in contrasted temperature conditions. To retrospectively study the effect of the ongoing climate warming on Larix decidua trees located in warm and cold conditions, i.e., at the bottom (1200 m) and the top (2300 m) of an elevational gradient, respectively. Dendroecological analysis of two groups of Larix decidua trees located at very low (1200 m) and very high (2300 m) elevations. Construction of climatic response curves for annual ring variables. Decomposition of the variance of the response models into their high and low frequency components. At Briancon, in the French Alps, the increase of the daily maximum temperature during the last 50 years is already almost 3 °C for the March–October period. The results reveal contrasted behaviors at both ends of the investigated elevational gradient. Basal area increment, ring width, and their earlywood and latewood components increase or level off at the top of the gradient, while they all strongly decrease at the bottom. At the bottom, the low frequency warming effect explains the recent ring width decrease, with no influence of the high frequency temperature variation. At the top, both the low frequency warming effect and the high frequency temperature effect explain each about half of the ring width variation encompassed by the model. Latewood density displays the same trend as ring width, while earlywood density decreases at both ends of the gradient. Such opposed trends of the radial growth time trends between the top (2300 m) and the bottom (1200 m) of the gradient reflects the respectively favorable and unfavorable effects of climate warming at such ends of this Larix decidua elevational gradient. We propose that the strong ring width decrease observed at the warmer bottom announces a coming dieback. The corresponding wood density decrease will affect wood hydraulic properties in a way that is unclear.

Eutrophication is one of the most serious environmental problems in the Skagerrak, and climate change may increase eutrophication in the future. This study focused on the effects of eutrophication and climate, and the interactions between these 2 factors, on biodiversity in rocky bottom communities on the outer Skagerrak coast. Monitoring data from the period 1990 to 2010 including macroalgae, sessile fauna and physical and hydrochemical data were analysed. In total, 45% of the total variance in the communities could be explained by physical factors and factors related to climate and eutrophication. The most important factors regulating species richness, diversity and community structure were wave exposure level and other factors varying with depth and biogeographical region. The benthic ecosystems were overall dominated by perennial and annual algae and rich communities of sessile macroinvertebrates. Climate variation and eutrophication variables had small but consistent impacts on the communities. Periods with high particle concentrations and with extreme temperatures negatively impacted benthic diversity. The responses to nutrients were variable and dependant on season and species. In January, when measurements best reflect available nutrients in the system, the species richness and diversity responses were concave, with the greatest richness and diversity in periods with intermediate nutrient concentrations. This pattern may indicate that our communities were in an elevated eutrophication state in periods with high nutrient concentrations and in the enrichment phase in periods with low concentrations. The study highlights the importance of regarding multiple stressors in combination and indicates that climate change may decrease benthic diversity in the Skagerrak in the future.

Unraveling the legacy effects of long-term climate warming is essential to for an integrated understanding of plant invasion success. However, knowledge regarding how these legacy influences invasive offspring and natural enemies remains lacking. This work was built on a long-term warming experiment established in 2012. Here, we selected invasive Solidago canadensis and performed a series of experiments to explore the effects of experimental warming on offspring S. canadensis from its native and invaded range, as well as the legacy effect of warming on three insect species, and three pathogens. The experience of long-term maternal warming facilitated the growth of offspring from invasive S. canadensis, regardless of the presence of insects or pathogens. This experience decreased insect growth when feeding on native S. canadensis, and inhibited pathogens when infecting invasive S. canadensis. Additionally, the presence of natural enemies could modulate the legacy effects of warming and population provenance. These results suggest that long-term climate warming could facilitate invasion success via coordinated increases in growth and defense, and that legacy effects of climate warming and maternal provenance are important for understanding the cascading effects of climate warming.

Parasitoids are key regulators of the population dynamics of their arthropod hosts, are integral to the structure and dynamics of food webs, and provide ecosystem services by suppressing agricultural pests. Despite their ecological and functional importance, relatively few studies have considered the effects of a warming climate on host–parasitoid interactions. The three primary modes through which parasitoids might respond to a warming climate are by (i) shifting distributions into cooler environments, (ii) altering phenology, and (iii) adjusting to persist in situ through phenotypic plasticity or evolutionary adaptation. Here, we focus on examples of altered distributions and phenology in response to climate warming. We suggest that the responses of parasitoids to elevated temperatures and the population dynamic consequences for their hosts will be linked to two key traits: the dispersal ability of both partners, and the host specificity of parasitoids. Effects of climate warming on host–parasitoid interactions will be complicated by interactions with other co‐occurring environmental changes, such as elevated carbon dioxide and nitrogen, and to interactions with competitors, mutualists, and antagonists. These factors will complicate efforts to generate predictive models of host–parasitoid interactions, for example in the context of the ecosystem service of biological pest control.

Global mean surface temperatures are increasing. All ecosystems are likely to be affected and there is much interest at present in predicting the effects. In freshwater environments, we expect to observe, among other things, effects similar to those observed under eutrophication, such as increases in zooplankton population density and biomass as a result of enhanced population growth rates. Lago Maggiore underwent rapid eutrophication during the 60s and 70s, with a return to oligotrophy during the 80s and the 90s. Thus, it provides a case study to test the hypothesized eutrophication-like effects of recent climate warming. More specifically, we compare zooplankton biomass and density during the exceptionally warm years of the recent oligotrophic phase with values during the non-warm years of oligotrophy, and during years of the mesotrophic phase. This permits an analysis of zooplankton biomass and density with respect to temperature increase compared with the effects of eutrophication. Zooplankton population density and biomass sharply increased in 2003, the warmest year of the last century, as a result of Cladocera, particularly Daphnia, attaining values typical of the mesotrophic phase. These values were exceptional compared to typical values and were strongly different from those attained during cooler years since re-oligotrophication. Mean annual values of zooplankton density and biomass recorded in 2003 were fully comparable to typical values during the mesotrophic period. This observation confirms the hypothesis of an overall eutrophication-like effect of climate warming. Seasonal trends, characterized by an earlier start of population growth, are consistent with the effects of an increase in water temperature, as observed in laboratory experiments on the reproductive and growth strategies of Daphnia.

Shallow lakes are highly vulnerable to damages caused by human activities and warming trends. To assess whether and how community structures of phytoplankton and nitrogen uptake respond to the combined effects of elevated temperature and eutrophication, we performed a mesocosm experiment in field by combining a 4.5 °C increase in temperature and the addition of phosphorus. Our results demonstrated that the combination of rising temperatures and phosphorus loading stimulated the maximum biomass built up by the phytoplankton community, and changed the phytoplankton community by significantly increasing the number of Chlorophyta and Cyanophyta, and decreasing that of Cryptophyta. We also examined the effects of climate warming and eutrophication on phytoplankton nitrogen uptake and dynamics using 15N tracer techniques. The addition of phosphorus slightly increased the phytoplankton nitrate uptake velocity and relative preference index, but decreased the nitrate uptake turnover time. Warming relatively increased the ammonium uptake velocity and the relative preference index, but decreased the ammonium turnover time. In kinetic studies, NH4+ exhibited a higher maximum uptake rate (Vmax) and a lower half-saturation constant (Ks) than NO3− substrates due to temperature elevation and the addition of phosphorus. Hence, warming and eutrophication increased the capacity of phytoplankton for NH4+ uptake and their affinity at low substrate concentrations. Thus, the combined effects of climate warming and phosphorus nutrient availability may increase the prevalence of Chlorophyta and Cyanophyta, and change the nitrogen cycling of aquatic ecosystems.

Climate change can hamper sustainable growth in the aquaculture industry by amplifying and adding to other environmental challenges. In Norway, salmon lice-induced mortality in wild salmonid populations is identified as a major risk factor for further expansion. Higher temperatures will induce increased production of salmon lice larvae, decreased developmental time from non-infective nauplii to infectious copepods, and higher infectivity of copepodids. In a warmer climate, a modelling exercise shows how these three factors lead to a significant increase in the infection pressure from farmed to wild salmonids, where the infectivity of copepodids is the term with the highest sensitivity to temperature changes. The total infection pressure gradually increases with increasing temperature, with an estimated twofold if the temperature increases from 9°C to 11°C. Thus, making it even harder to achieve a sustainable expansion of the industry with rising water temperature. This study demonstrates how bio-hydrodynamic models might be used to assess the combined effects of future warmer climate and infection pressure from salmon lice on wild salmonids. The results can be used as an early warning for the fish-farmers, conservation stakeholders and the management authorities, and serve as a tool to test mitigation strategies before implementation of new management plans.

At high population size, migratory caribou (Rangifer tarandus) are regulated by forage abundance in their summer range. Climate warming likely affects forage availability by increasing productivity and advancing phenology of vegetation. Our objective was to investigate the combined effects of browsing and climate warming on the availability of dwarf birch (Betula glandulosa). We simulated direct (warming, with open-top chambers) and indirect (increased nutrient cycling) effects of climate warming in interaction with simulated browsing (leaf stripping) from 2009 to 2013 in Nunavik, Canada. We measured the effect of treatments on dwarf birch biomass and phenology. Moderate and heavy browsing reduced the estimated biomass of birch leaves by 14% and 34%, respectively. Fertilization did not increase the biomass of birch leaves, but increased the biomass of another forage, Poaceae. The warming treatment advanced the opening of birch leaves by 4 days (95% CI: [3, 6]) in 2011 and 7 [5, 8] days in 2013, the two years colder than average. The absence of significant phenological shifts in warmed plots during warmer springs suggests that established dwarf birches may have reached a threshold in a limiting resource, likely soil moisture, under which they cannot respond to further warming. Our results demonstrate that browsing can reduce forage biomass, but the variability in caribou populations could provide windows of opportunity for shrub growth.

It is thought that future climate change is likely to foster biological invasions, but effects of climate warming on invasions in recent decades are little explored. In this paper, we analyse the history of the spread of Ambrosia artemisiifolia (common ragweed) in central Europe in order to determine the effects of climate warming. In addition, we infer the likely history of this species’ spread and current distribution from incomplete documentation. The area studied in central Europe includes Austria, the Czech Republic, Germany, Hungary, Liechtenstein, Slovakia, Slovenia and Switzerland. These countries were represented by a lattice of grid cells of size 5' × 3' (~ 6 × 6 km2), and we modelled this species’ increase in range in this grid from 1900 to 2010 at an annual resolution. The spread was modelled to be driven by the spatio-temporal variation in environmental suitability of grid cells as determined by climatic conditions and land use, propagule production and dispersal from invaded cells, and ‘background’ introductions from unknown sources. A hierarchical Bayesian modelling approach accounted for lagged and incomplete records of occurrence and spatio-temporal variation in sampling intensity. We fitted models with different representations of climate variation over time, and further contrasted the hierarchical model to a simplified model, which assumed that records accurately reflected the species’ actual spread. Climatic conditions were the most important determinants of environmental suitability for invasion, and suitability also increased with increase in the proportion of urban area and length of railways in grid cells. Temperature was, on average, 2.7 °C higher in the environmentally more suitable cells than in the less suitable cells. The pattern in the spread was determined by local range expansion frommultiple, spatially scattered points of introduction. Assuming a linear trend in climate warming over the modelling period provided a better model fit than using annual weather conditions or the long-term average of the climate. The model estimated that by 2010 only about 60% of the actually invaded grid cells were recorded, and records lagged behind actual colonizations by years up to decades. Inferences of the hierarchical and simplified models differed quantitatively. We conclude that by using our modelling framework it is possible to separate spatial effects of climate on the spread of non-native species from temporal effects, and that climate warming has already promoted the spread of Ambrosia artemisiifolia in central Europe. The recorded distribution reflects only a part of this species’ actual distribution. Properly accounting for incomplete records hence improves inferences about the dynamics of spread.

The article presents the results of studying the effects of current climatic warming for both surface and subsurface water runoffs in North-East Russia, where the Main Watershed of the Earth separates it into the Arctic and Pacific continental slopes. The process of climatic warming is testified by continuous weather records during 80-100 years and longer periods. Over the Arctic slope and in the northern areas of the Pacific slope, climatic warming results in a decline in a total runoff of rivers whereas the ground-water recharge becomes greater in winter low-level conditions. In the southern Pacific slope and in the Sea of Okhotsk basin, the effect of climatic warming is an overall increase in total runoff including its subsurface constituents. We believe these peculiar characters of river runoff there to be related to the cryolithic zone environments. Over the Arctic slope and the northern Pacific slope, where cryolithic zone is continuous, the total runoff has its subsurface constituent as basically resulting from discharge of ground waters hosted in seasonally thawing rocks. Warmer climatic conditions favor growth of vegetation that needs more water for the processes of evapotranspiration and evaporation from rocky surfaces in summer seasons. In the Sea of Okhotsk basin, where the cryolithic zone is discontinuous, not only ground waters in seasonally thawing layers, but also continuous taliks and subpermafrost waters participate in processes of river recharges. As a result, a greater biological productivity of vegetation cover does not have any effect on ground-water supply and river recharge processes. If a steady climate warming is provided, a continuous cryolithic zone can presumably degrade into a discontinuous and then into an island-type permafrost layer. Under such a scenario, there will be a general increase in the total runoff and its subsurface constituent. From geoecological viewpoints, a greater runoff will have quite positive effects, whereas some minor negative consequences of it can be successfully prevented.

Encroachment of shrubs into the unique pastoral grassland ecosystems of the Tibetan Plateau has significant impact on ecosystem services, especially forage production. We developed a process-based ecohydrological model to identify the relative importance of the main drivers of shrub encroachment for the alpine meadows within the Qinghai province. Specifically, we explored the effects of summer livestock grazing (intensity and type of livestock) together with the effects of climate warming, including interactions between herbaceous and woody vegetation and feedback loops between soil, water and vegetation. Under current climatic conditions and a traditional herd composition, an increasing grazing intensity above a threshold value of 0.32±0.10 large stock units (LSU) ha−1 day−1 changes the vegetation composition from herbaceous towards a woody and bare soil dominated system. Very high grazing intensity (above 0.8 LSU ha−1 day−1) leads to a complete loss of any vegetation. Under warmer conditions, the vegetation showed a higher resilience against livestock farming. This resilience is enhanced when the herd has a higher browser:grazer ratio. A cooler climate has a shrub encroaching effect, whereas warmer conditions increase the cover of the herbaceous vegetation. This effect was primarily due to season length and an accompanied competitive loss of slower growing shrubs, rather than evaporative water loss leading to less soil water in deeper soil layers for deeper rooting shrubs. If climate warming is driving current shrub encroachment, we conclude it is only indirectly so. It would be manifest by an advancing shrubline and could be regarded as a climatic escape of specific shrub species such as Potentilla fruticosa. Under the recent high intensity of grazing, only herding by more browsing animals can potentially prevent both shrub encroachment and the complete loss of herbaceous vegetation.