Development Of Ecological Theory Research Articles

Dynamic altruistic cooperation within breast tumors

BackgroundSocial behaviors such as altruism, where one self-sacrifices for collective benefits, critically influence an organism’s survival and responses to the environment. Such behaviors are widely exemplified in nature but have been underexplored in cancer cells which are conventionally seen as selfish competitive players. This multidisciplinary study explores altruism and its mechanism in breast cancer cells and its contribution to chemoresistance.MethodsMicroRNA profiling was performed on circulating tumor cells collected from the blood of treated breast cancer patients. Cancer cell lines ectopically expressing candidate miRNA were used in co-culture experiments and treated with docetaxel. Ecological parameters like relative survival and relative fitness were assessed using flow cytometry. Functional studies and characterization performed in vitro and in vivo include proliferation, iTRAQ-mass spectrometry, RNA sequencing, inhibition by small molecules and antibodies, siRNA knockdown, CRISPR/dCas9 inhibition and fluorescence imaging of promoter reporter-expressing cells. Mathematical modeling based on evolutionary game theory was performed to simulate spatial organization of cancer cells.ResultsOpposing cancer processes underlie altruism: an oncogenic process involving secretion of IGFBP2 and CCL28 by the altruists to induce survival benefits in neighboring cells under taxane exposure, and a self-sacrificial tumor suppressive process impeding proliferation of altruists via cell cycle arrest. Both processes are regulated concurrently in the altruists by miR-125b, via differential NF-κB signaling specifically through IKKβ. Altruistic cells persist in the tumor despite their self-sacrifice, as they can regenerate epigenetically from non-altruists via a KLF2/PCAF-mediated mechanism. The altruists maintain a sparse spatial organization by inhibiting surrounding cells from adopting the altruistic fate via a lateral inhibition mechanism involving a GAB1-PI3K-AKT-miR-125b signaling circuit.ConclusionsOur data reveal molecular mechanisms underlying manifestation, persistence and spatial spread of cancer cell altruism. A minor population behave altruistically at a cost to itself producing a collective benefit for the tumor, suggesting tumors to be dynamic social systems governed by the same rules of cooperation in social organisms. Understanding cancer cell altruism may lead to more holistic models of tumor evolution and drug response, as well as therapeutic paradigms that account for social interactions. Cancer cells constitute tractable experimental models for fields beyond oncology, like evolutionary ecology and game theory.

Reproductive senescence and mating tactic interact and conflict to drive reproductive success in a passerine.

An understanding of the drivers of individual fitness is a fundamental component of evolutionary ecology and life-history theory. Reproductive senescence, mate and mating tactic choice and latent heterogeneity in individual quality interact to affect individual fitness. We sought to disentangle the effects of these fitness drivers, where longitudinal data are required to understand their respective impacts. We used reproductive allocation and success data from a long-term (1989-2018) study of white-throated dippers Cinclus cinclus in Switzerland to simultaneously examine the effects of female and male age, mating tactic, nest initiation date and individual heterogeneity on reproductive performance. We modelled quadratic and categorical effects of age on reproductive parameters. The probability of polygyny increased with age in both sexes before declining in older age classes. Similarly, hatching probability in monogamous pairs and the number of nestlings hatched in both monogamous and polygynous pairs increased with female age before declining later in life. As predicted, offspring survival in monogamous pairs increased with male age before declining in older age classes, but male age had no effect on offspring survival in polygynous nesting attempts. Our results demonstrate that parental age, mating tactic and individual heterogeneity all affect reproductive success, and that the impacts of senescent decline are expressed across different demographic components as a function of sex-specific senescent decline and mating tactic.

Biomass Allocation Responses to Root Interactions in Wheat Cultivars Support Predictions of Crop Evolutionary Ecology Theory.

The goal of agriculture is to optimize the population yield, but natural selection has produced active competition among plants, which decreases population performance. Therefore, cultivar breeding should be based on group selection, increasing yield by weakening individual competitive responses. We hypothesize that this has occurred inadvertently to some degree, so modern cultivars have weakened competitive traits and responses, such as reduced root proliferation in response to neighboring roots. We conducted a field experiment with eight cultivars of spring wheat that have been released over the last hundred years, which we grew at two densities. Two contrasting wheat cultivars, a landrace and a modern cultivar, were used in a second field experiment on competition within and between the two cultivars to quantify their competitiveness. Finally, a greenhouse experiment was conducted with these two cultivars gown (a) in mixture and monoculture, (b) at four densities, (c) two watering levels, and (d) with permeable vs. non-permeable soil dividers, to study root proliferation responses to competition. Results of field experiment 1 showed that the population aboveground biomass (AGB) had increased, while belowground biomass had decreased over the course of breeding, so that the root to shoot ratio (R/S) was negatively correlated with the release year of the cultivar. The landrace had stronger competitiveness than the modern cultivar in the field experiment 2. There was clear evidence of root proliferation and a resultant reduction in AGB in response to neighboring roots in the greenhouse experiment, and the modern variety showed less root proliferation in response to neighbors. We conclude that the newer cultivar was a weaker competitor but higher-yielding in two ways: (1) it had higher reproductive effort and therefore less allocation to structures that increase competitive ability, and (2) it had reduced root proliferation in response to the roots of neighboring plants. Our results show that wheat plants change their biomass allocation in response to resource levels and the presence of neighboring roots. The presence of root proliferation in the modern cultivar, albeit less than in the landrace, suggests that further increases in yield via group selection are possible.

Application and progress of sexual selection and sexual conflict theory in plant reproductive evolutionary ecology

Application and progress of sexual selection and sexual conflict theory in plant reproductive evolutionary ecology

Trait shifts in bird communities from primary forest to human settlements in Mexican seasonal forests. Are there ruderal birds?

Agriculture, cattle grazing, and human settlements negatively affect bird biodiversity, driving the loss of ecologically specialized species and favoring the dominance of generalists. Because ecological pressures define organisms’ success by acting on their intrinsic traits, biodiversity loss due to anthropization might cause directional trait shifts. Here, we use a trait-based approach to find empirical evidence of trait-shifts in bird communities across an anthropization gradient in seasonal forests in central Mexico. We performed point-count bird surveys within a region of tropical deciduous and seasonal oak forests considering three degrees of anthropization: primary forest, secondary growth, and human settlements. A multivariate analysis (PCA) showed similar trait-covariation patterns for both forest types; in the anthropized habitat the bird communities exhibited shorter life-cycles, higher fecundity, and broader ecological niches (diet, foraging habitat, and nesting resources) than those in the primary forests. Our finding of directional trait shifts resembles Evolutionary Ecological Strategies Theory (EES) predictions for successful organisms within highly disturbed anthropized habitats, which are known as a “ruderal adaptative strategy” in the EES framework. The use of trait-based approaches could improve ecological generalizations in bird communities, leading to a better understanding of avian biodiversity's responses to anthropization.

Allometry and Yield Stability of Cereals.

Crop plants grow, and then, they allocate resources to different structures, including seeds and fruits, which represent yield in most crops. We define the yield stability of a genotype as its ability to reduce the effects of temporal variation in resources and conditions on yield production, and we argue that yield stability can be understood in terms of two processes: (1) crop survival and growth (biomass production): the ability of the crop plants to survive and produce biomass under the range of conditions to which it is exposed and (2) the pattern of allocation of this biomass to yield across this range of conditions. Plant breeders and crop physiologists have focused on (1), but much less attention has been paid to (2). We hypothesize that (2) is primarily the result of reproductive allometry: the quantitative relationship between vegetative and reproductive biomass. Ecological theory and the allometric models we present predict a tradeoff between (a) the ability of a genotype to produce yield over a wide variety of conditions and (b) its ability to produce very high yields under optimal or near-optimal conditions. We reanalyze the data from two recent studies, and the results are consistent with this hypothesis. Yield stability in crops corresponds to bet-hedging in evolutionary ecological theory. It is the most appropriate strategy for smallholder farmers in developing countries, a group that comprises most of the farmers in the world. Researchers and crop breeders need to rethink their objectives if they want to develop optimal varieties for these farmers.

A white noise approach to evolutionary ecology

Although the evolutionary response to random genetic drift is classically modelled as a sampling process for populations with fixed abundance, the abundances of populations in the wild fluctuate over time. Furthermore, since wild populations exhibit demographic stochasticity and since random genetic drift is in part due to demographic stochasticity, theoretical approaches are needed to understand the role of demographic stochasticity in eco-evolutionary dynamics. Here we close this gap for quantitative characters evolving in continuously reproducing populations by providing a framework to track the stochastic dynamics of abundance density across phenotypic space using stochastic partial differential equations. In the process we develop a set of heuristics to operationalize the powerful, but abstract theory of white noise and diffusion-limits of individual-based models. Applying these heuristics, we obtain stochastic ordinary differential equations that generalize classical expressions of ecological quantitative genetics. In particular, by supplying growth rate and reproductive variance as functions of abundance densities and trait values, these equations track population size, mean trait and additive genetic variance responding to mutation, demographic stochasticity, random genetic drift, deterministic selection and noise-induced selection. We demonstrate the utility of our approach by formulating a model of diffuse coevolution mediated by exploitative competition for a continuum of resources. In addition to trait and abundance distributions, this model predicts interaction networks defined by niche-overlap, competition coefficients, or selection gradients. Using a high-richness approximation, we find linear selection gradients and competition coefficients are uncorrelated, but magnitudes of linear selection gradients and quadratic selection gradients are both positively correlated with competition coefficients. Hence, competing species that strongly affect each other’s abundance tend to also impose selection on one another, but the directionality is not predicted. This approach contributes to the development of a synthetic theory of evolutionary ecology by formalizing first principle derivations of stochastic models tracking feedbacks of biological processes and the patterns of diversity they produce.

Evolutionary ecology of Lyme Borrelia.

The bacterial genus, Borrelia, is comprised of vector-borne spirochete species that infect and are transmitted from multiple host species. Some Borrelia species cause highly-prevalent diseases in humans and domestic animals. Evolutionary, ecological, and molecular research on many Borrelia species have resulted in tremendous progress toward understanding the biology and natural history of these species. Yet, many outstanding questions, such as how Borrelia populations will be impacted by climate and land-use change, will require an interdisciplinary approach. The evolutionary ecology research framework incorporates theory and data from evolutionary, ecological, and molecular studies while overcoming common assumptions within each field that can hinder integration across these disciplines. Evolutionary ecology offers a framework to evaluate the ecological consequences of evolved traits and to predict how present-day ecological processes may result in further evolutionary change. Studies of microbes with complex transmission cycles, like Borrelia, which interact with multiple vertebrate hosts and arthropod vectors, are poised to leverage the power of the evolutionary ecology framework to identify the molecular interactions involved in ecological processes that result in evolutionary change. Using existing data, we outline how evolutionary ecology theory can delineate how interactions with other species and the physical environment create selective forces or impact migration of Borrelia populations and result in micro-evolutionary changes. We further discuss the ecological and molecular consequences of those micro-evolutionary changes. While many of the currently outstanding questions will necessitate new experimental designs and additional empirical data, many others can be addressed immediately by integrating existing molecular and ecological data within an evolutionary ecology framework.

Tree species classification using structural features derived from terrestrial laser scanning

Fast and automated collection of forest data, such as species composition information, is required to support climate mitigation actions. Recently, there have been significant advances in the use of terrestrial laser scanning (TLS) instruments, which facilitate the capture of detailed forest structure. However, for tree species recognition the structural information from TLS has mainly been used to complement spectral information. TLS-only classification studies have been limited in size and diversity of plot forest types. In this paper, we investigate the potential of TLS for tree species classification. We used quantitative structure models to determine 17 structural tree features. These features were computed for 758 trees of five tree species, including two understory species, of a 1.4 hectare mixed deciduous forest plot. Three classification methods were compared: k-nearest neighbours, multinomial logistic regression and support vector machine. We assessed the potential underlying causes for structural differences with principal component analysis. We obtained classification success rates of approximately 80%, however, with producer accuracies for three of the five species ranging from 0 to 60%. Low producer accuracies were the result of a high intra- and low inter-species variability. These effects were, respectively, caused by a high size-dependency of the structural features and a convergence of structural traits across species as a result of the individual tree position in the forest canopy and shade tolerance. Nevertheless, the producer accuracies could be improved through sensitivity vs. specificity trade-offs, with over 50% for all species being obtainable. The high intra -and low inter-species variability complicate the classification. Furthermore, the classification performance and best classification method greatly depend on its targeted application. In conclusion, this study proves the added value of TLS for tree species classification but also shows that TLS opens up potential for testing and further development of ecological theory.

An Enhanced Genetic Algorithm for Parameter Estimation of Sinusoidal Signals

Estimating the parameters of sinusoidal signals is a fundamental problem in signal processing and in time-series analysis. Although various genetic algorithms and their hybrids have been introduced to the field, the problems pertaining to complex implementation, premature convergence, and accuracy are still unsolved. To overcome these drawbacks, an enhanced genetic algorithm (EGA) based on biological evolutionary and mathematical ecological theory is originally proposed in this study; wherein a prejudice-free selection mechanism, a two-step crossover (TSC), and an adaptive mutation strategy are designed to preserve population diversity and to maintain a synergy between convergence and search ability. In order to validate the performance, benchmark function-based studies are conducted, and the results are compared with that of the standard genetic algorithm (SGA), the particle swarm optimization (PSO), the cuckoo search (CS), and the cloud model-based genetic algorithm (CMGA). The results reveal that the proposed method outperforms the others in terms of accuracy, convergence speed, and robustness against noise. Finally, parameter estimations of real-life sinusoidal signals are performed, validating the superiority and effectiveness of the proposed method.

Evolution of bacteria specialization along an antibiotic dose gradient.

Antibiotic and pesticide resistance of pathogens are major and pressing worldwide issues. Resistance evolution is often considered in simplified ecological contexts: treated versus nontreated environments. In contrast, antibiotic usually present important dose gradients: from ecosystems to hospitals to polluted soils, in treated patients across tissues. However, we do not know whether adaptation to low or high doses involves different phenotypic traits, and whether these traits trade‐off with each other. In this study, we investigated the occurrence of such fitness trade‐offs along a dose gradient by evolving experimentally resistant lines of Escherichia coli at different antibiotic concentrations for ∼400 generations. Our results reveal fast evolution toward specialization following the first mutational step toward resistance, along with pervasive trade‐offs among different evolution doses. We found clear and regular fitness patterns of specialization, which converged rapidly from different initial starting points. These findings are consistent with a simple fitness peak shift model as described by the classical evolutionary ecology theory of adaptation across environmental gradients. We also found that the fitness costs of resistance tend to be compensated through time at low doses whereas they increase through time at higher doses. This cost evolution follows a linear trend with the log‐dose of antibiotic along the gradient. These results suggest a general explanation for the variability of the fitness costs of resistance and their evolution. Overall, these findings call for more realistic models of resistance management incorporating dose‐specialization.

Form, function and physics: the ecology of biogenic stabilisation

PurposeThe objective of this work is to better understand the role that biological mediation plays in the behaviour of fine sediments. This research is supported by developments in ecological theory recognising organisms as “ecosystem engineers” and associated discussion of “niche construction”, suggesting an evolutionary role for habitat modification by biological action. In addition, there is acknowledgement from engineering disciplines that something is missing from fine sediment transport predictions.Materials and methodsAdvances in technology continue to improve our ability to examine the small-scale 2D processes with large-scale effects in natural environments. Advanced molecular tools can be combined with state-of-the-art field and laboratory techniques to allow the discrimination of microbial biodiversity and the examination of their metabolic contribution to ecosystem function. This in turn can be related to highly resolved measurements and visualisation of flow dynamics.Results and discussionRecent laboratory and field work have led to a paradigm shift whereby hydraulic research has to embrace biology and biogeochemistry to unravel the highly complex issues around on fine sediment dynamics. Examples are provided illustrating traditional and more recent approaches including using multiple stressors in fully factorial designs in both the laboratory and the field to highlight the complexity of the interaction between biology and sediment dynamics in time and space. The next phase is likely to rely on advances in molecular analysis, metagenomics and metabolomics, to assess the functional role of microbial assemblages in sediment behaviour, including the nature and rate of polymer production by bacteria, the mechanism of their influence on sediment behaviour.ConclusionsTo fully understand how aquatic habitats will adjust to environmental change and to support the provision of various ecosystem services, we require a holistic approach. We must consider all aspects that control the distribution of sediment and the erosion-transport-deposition-consolidation cycle including biological and chemical processes, not just the physical. In particular, the role of microbial assemblages is now recognised as a significant factor deserving greater attention across disciplines.

The Best Way to Rob a Bank

Cohen and Machalek’s (1988) evolutionary ecological theory of crime explains why obscure forms of predation can be the most lucrative. Sutherland explained that it is better to rob a bank at the point of a pen than of a gun. The US Savings and Loans scandal of the 1980s suggested ‘the best way to rob a bank is to own one’. Lure constituted by the anomie of warfare and transition to capitalism in former Yugoslavia revealed that the best way to rob a bank is to control the regulatory system: that is, to control a central bank. This makes possible theft of all the people’s money in a society. The criminological imagination must attune to anomie created by capitalism, and to the evolutionary ecology of lure.

Theoretical Approaches in Evolutionary Ecology: Environmental Feedback as a Unifying Perspective.

Evolutionary biology and ecology have a strong theoretical underpinning, and this has fostered a variety of modeling approaches. A major challenge of this theoretical work has been to unravel the tangled feedback loop between ecology and evolution. This has prompted the development of two main classes of models. While quantitative genetics models jointly consider the ecological and evolutionary dynamics of a focal population, a separation of timescales between ecology and evolution is assumed by evolutionary game theory, adaptive dynamics, and inclusive fitness theory. As a result, theoretical evolutionary ecology tends to be divided among different schools of thought, with different toolboxes and motivations. My aim in this synthesis is to highlight the connections between these different approaches and clarify the current state of theory in evolutionary ecology. Central to this approach is to make explicit the dependence on environmental dynamics of the population and evolutionary dynamics, thereby materializing the eco-evolutionary feedback loop. This perspective sheds light on the interplay between environmental feedback and the timescales of ecological and evolutionary processes. I conclude by discussing some potential extensions and challenges to our current theoretical understanding of eco-evolutionary dynamics.

The Best Way to Rob a Bank

Cohen and Machalek’s (1988) evolutionary ecological theory of crime explains why obscure forms of predation can be the most lucrative. The lure of white-collar crime takes off through the anomic conditions of warfare and the ‘creative destruction’ of capitalism. Edwin Sutherland explained that it is better to rob a bank at the point of a pen than the point of a gun. The Savings and Loans scandal suggested ‘the best way to rob a bank is to own it’. Lure constituted by the anomie of warfare and transition to capitalism in Yugoslavia revealed that the best way to rob a bank is to control the regulatory system. It is not to own a bank but to control a central bank. This makes possible theft not only of massive chunks of the people’s money, but of all the money in all the wallets of the people, in the safes of all the businesses and all the banks of a society. The criminological imagination must attune to anomie created by both boom and bust in capitalism, and to the evolutionary ecology of lure.

The ex-pat effect: presence of recent Western immigrants is associated with changes in age at first birth and birth rate in a Maya population from rural Guatemala

Background: Economic transitions expose indigenous populations to a variety of ecological and cultural challenges, especially regarding diet and stress. These kinds of challenges are predicted by evolutionary ecological theory to have fitness consequences (differential reproduction) and, indeed, are often associated with changes in fertility dynamics. It is currently unclear whether international immigration might impact the nature of such an economic transition or its consequences for fertility.Aim: To examine measures of fertility, diet and stress in two economically transitioning Maya villages in Guatemala that have been differentially exposed to immigration by Westerners.Subjects and methods: This study compared Maya women’s ages at first birth and birth rates between villages and investigated whether these fertility indicators changed through time. It also explored whether the villages differed in relation to diet and/or a proxy of stress.Results: It was found that, in the village directly impacted by immigration, first births occurred earlier, but birth rate was slower. In both villages, over the sampled time window, age at first birth increased, while birth rate decreased. The villages do not differ significantly in dietary indicators, but the immigration-affected village scored higher on the stress proxy.Conclusion: Immigration can affect fertility in host communities. This relationship between immigration and fertility dynamics may be partly attributable to stress, but this possibility should be evaluated prospectively in future research.

Conditional Handicaps in Exuberant Lizards: Bright Color in Aggressive Males Is Correlated with High Levels of Free Radicals

Two non-independent theories in evolutionary ecology, the immunocompetence and the oxidative handicap hypotheses, may explain maintenance of genetic variation and signal honesty through genic capture in sexual selection biology. Thus, polygenic traits, like body condition, could help maintain variation in signalling traits under strong, directional sexual selection while maintaining signal honesty. The immunocompetence and oxidative handicap hypotheses are complementary in this regard in that hormones (most often steroids) essential for sexual signalling also carry costs, including increases in potentially damaging reactive oxygen species (ROS). Here we combine (at least) two of these hypotheses in a study of morph-specific condition and free radical effects on signalling traits (head coloration) in males of a polymorphic lizard, the Australian painted dragon (Ctenophorus pictus). Males differ in head colour (red, orange, yellow, hereto forth collectively ‘yellow-reds’), with these morphs showing reproductive tactics and behaviour in a graded fashion of aggression and dominance (red highest levels). A blue morph recently emerged in our study population and has never been behaviourally characterised. Body condition varied significantly in its relationship with superoxide among the four morphs, with males in better condition showing higher superoxide levels in ‘yellow-reds’ (least so in red males). Blue males contrasted markedly by showing lower superoxide levels in males in better condition, perhaps facilitated by no (or reduced) dermal deposition of pigmentation. Colour degradation with loss in condition from yellow to red males, suggesting that red males (i.e., genes associated within a more aggressive morph) is more able to maintain colour with superoxide acting as a potential handicap. This result is consistent with handicap principles in that males with the more pronounced signal carry a higher cost (higher ROS levels) when being in better body condition, while maintaining more vivid coloration (the condition-dependent trait).

Regulatory Science: Mathematical vs. Statistical Models

Natural resource companies do not object to environmental regulations that are consistent and support predictability. Consistency and predictability are critical for decision making under conditions of uncertainty. Natural ecosystems are inherently variable across a broad range of temporal and spatial scales; climate change, drought, and societal desires for sustainability make people more aware of this variability. The science used for development and enforcement of environmental regulations has not kept pace with developments in ecological theory and the analytical tools capable of describing, characterizing, classifying, and predicting natural ecosystems as well as distinguishing natural variability from anthropogenic changes.Because natural resource industries (agriculture, energy, mining) provide the base for all economic and societal activities it is critical that environmental statutes and regulations be regularly updated to use the most technically sound and legally defensible scientific knowledge and tools.Mathematical models were the tools of choice when environmental statutes and regulations were introduced, perhaps because they were successfully applied to static components of the built environment such as buildings and bridges. While their limitations for highly variable natural ecosystems were accepted then, there is now no benefit to not replacing them with statistical models.This paper describes limitations in policy and regulatory decision-making based on mathematical models and explains how the appropriate statistical models avoid the subjectivity and rigidity of the former. Changing the basis of determining and justifying policy and environmental regulations is consistent with the concepts of regulatory science applied to human health.https://doi.org/10.21423/jrs-v04n04p010 (DOI assigned 5/14/2019)

Multi-offspring genetic algorithm and its application to the traveling salesman problem

The paper provides a multi-offspring genetic algorithm (MO-GA) in accordance with biological evolutionary and mathematical ecological theory, and illustrates its application in the traveling salesman problem (TSP) in comparison to the basic genetic algorithm (BGA). In MO-GA, the number of offsprings is significantly increased as compared to the BGA. MO-GA increases the probability of producing excellent individuals, and also makes the population more competitive, thus yielding considerable improvement. Test results with six TSP examples show that MO-GA has faster speed, and the number and time of iterations are significantly reduced as compared to the BGA.

不同干扰下阿拉善荒漠啮齿动物优势种对气候变化的响应

PDF HTML阅读 XML下载 导出引用 引用提醒 不同干扰下阿拉善荒漠啮齿动物优势种对气候变化的响应 DOI: 10.5846/stxb201408061564 作者: 作者单位: 内蒙古农业大学生态环境学院,内蒙古农业大学生态环境学院,内蒙古自治区林业监测规划院,内蒙古农业大学生态环境学院,中国农业科学研究院草原研究所,内蒙古医科大学 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(30160019, 30560028, 30760044, 31160096);公益性行业(农业)科研专项经费项目(201203041);中央级公益性科研院所基本科研业务费专项资金(中国农业科学院草原研究所)资助项目(1610332015012) Responses of dominant rodentspecies to climate change in different disturbed habitats in the Alashan desert Author: Affiliation: College of Ecology and Environmental Science, Inner Mongolia Agricultural University,,College of Ecology and Environmental Science, Inner Mongolia Agricultural University,,,College of Ecology and Environmental Science, Inner Mongolia Agricultural University,, 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:气候变化已对物种分布范围和丰富度产生了极大的影响。荒漠生态系统对气候变化的反应可能更加敏感。作为荒漠生态系统的重要组成者,了解荒漠啮齿动物特别是优势鼠种将对气候变化如何响应,对于荒漠地区生物多样性的维持将具有重要意义。2002-2010年,采用标志重捕法对阿拉善荒漠4种不同生境下啮齿动物优势种群进行了研究,分别利用Spearman相关分析以及典范对应分析(Canonical Correspondence analysis,CCA)对啮齿动物优势种群动态与年平均温度和年降水量的相关性进行了分析。结果表明,不同啮齿动物优势种对温度和降雨的响应不同,尤其以子午沙鼠表现最为显著。跳鼠对温度的适宜性要高于仓鼠科的子午沙鼠和黑线仓鼠,而仓鼠科啮齿动物对降雨的适宜性高于跳鼠。较小尺度上的人为干扰更可能从改变食性和生境的途径上加剧或缓冲降雨对荒漠啮齿动物优势种的影响,而不是改变温度对啮齿动物的作用。 Abstract:The Northern Hemisphere of the earth has been experiencing remarkable climate warming in last century. Climate change has a profound influence on the distribution, range, and richness of species. Temperature and precipitation are two indicators of climate in most of studies. Because hydrothermic factor has a significant effect on desert ecosystem, it is particularly sensitive to climate fluctuations. Rodents are especially important components of the desert ecosystem, and are dominant species that play a key role in these systems. In addition, desert rodents have played an important role in the development of ecological theory and in the understanding of adaptations to xeric environments. Therefore, understanding the response of dominant rodent species to climate change is significant to biodiversity conversion. Desert ecosystems in China, compared with similar ecosystems in other continents, suffer more disturbances from human activities. Alxa desert is a typical desert ecosystem in China. Annual mean temperatures of Alxa desert have risen 9.05 degrees, and precipitation has increased 23.46mm in last decade. Against this Background, the response of desert rodents, especially dominant rodent species, to climate change, and how this response influences by human disturbances are keeping unknown. A study was conducted from 2002 to 2010 at prohibited-grazing, rotational-grazing, over-grazing, and cultivated sites to investigate the response of dominant rodent species to climate change in Alashan, Inner Mongolia, China. Rodent species were identified among and monitored with a live-trapping method. We trapped nine species including Dipus sagitta, Stylodipus andrewsi, Allactaga sibirica, Phodopus roborovskii, Cricetulus barabensis, Allocricetulus eversmanni, Meriones meridianus, Meriones unguiculatus and Spermophilus alaschanicus. M. meridianus was the dominant rodent species in prohibited-grazing and cultivated sites. However, A. sibirica and D. sagitta was the dominant rodent species in over-grazing and rotational grazing sites, respectively. The relationships of annual mean temperature and precipitation with rodent abundance were analyzed with Spearman correlation analysis and canonical correspondence analysis. The results showed that the response to temperature and precipitation was variable across rodent species. M. meridianus abundance was significantly correlated with annual precipitation in the previous year and annual mean temperature. The abundance optimum of A. sibirica and D. sagitta with respect to temperature was higher than that of M. meridianus and C. barabensis, but this pattern was reversed with respect to precipitation. Effect of temperature on desert rodent should be worked through influencing biology and ecological characteristics of animal, while precipitation affects the rodents through changing food resource and habitat. Precipitation has a pulse effect on M. meridianus abundance. These results suggested that human disturbance, occurring at a smaller spatial scale, should intensify or buffer the influence of precipitation rather than temperature on the dominant rodent species through altering food resource availability and habitat quality. These disturbances complex the response of rodent species to climate change, and have a further effect to community structure of desert rodent. 参考文献 相似文献 引证文献