首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
《Ecological modelling》2007,208(1):25-40
A shift in the basic philosophy of nature developed by Francis Bacon, Renè Descartes, and Isaac Newton, has been suggested but for the most part rejected within mainstream science. It suggests the need for viewing nature as a deeply organic and connected system of relationships that is not necessarily or readily submissive to reductive thinking and analysis. Ecosystem design within the construct of a field called ecological engineering poses fundamental questions with respect to the philosophy of nature upon which our current scientific paradigm is predominantly based. In an effort to foster development of rigorous, quantitative methods for developing insight into complex ecosystem phenomena we propose systems and engineering ecology—an integrated science comprised of principles from environ theory, ascendency theory, exergy theory, emergy theory, ecological network analysis and ecological modelling, synthesized through the formal agency of systems science. We contend that ecological engineering will be limited in its robustness apart from development of rigorous systems-based sciences that are quantitative and incorporate the complex, emergent properties of ecosystem. We justify our proposed framework on the philosophical paradox of transferring aspects of traditional engineering design into ecological engineering and on the four causes of Aristotle.  相似文献   

2.
Species, habitats, and ecosystems are increasingly exposed to multiple anthropogenic stressors, fueling a rapidly expanding research program to understand the cumulative impacts of these environmental modifications. Since the 1970s, a growing set of methods has been developed through two parallel, sometimes connected, streams of research within the applied and academic realms to assess cumulative effects. Past reviews of cumulative effects assessment (CEA) methods focused on approaches used by practitioners. Academic research has developed several distinct and novel approaches to conducting CEA. Understanding the suite of methods that exist will help practitioners and academics better address various ecological foci (physiological responses, population impacts, ecosystem impacts) and ecological complexities (synergistic effects, impacts across space and time). We reviewed 6 categories of methods (experimental, meta-analysis, single-species modeling, mapping, qualitative modeling, and multispecies modeling) and examined the ability of those methods to address different levels of complexity. We focused on research gaps and emerging priorities. We found that no single method assessed impacts across the 4 ecological foci and 6 ecological complexities considered. We propose that methods can be used in combination to improve understanding such that multimodel inference can provide a suite of comparable outputs, mapping methods can help prioritize localized models or experimental gaps, and future experiments can be paired from the outset with models they will inform.  相似文献   

3.
城市生态系统的格局和过程   总被引:4,自引:0,他引:4  
城市生态系统是人类活动影响下的复合生态系统。人为的开发利用活动和局地的生物物理条件形成了城市特有的景观格局。城市发展改变了自然的生物栖息环境,从根本上改变了生态系统的结构、过程、功能,以及所提供的各种服务。这种改变最终又会影响人类自身的健康生存。文章综述了国内外有关城市景观格局和和重要生态过程之间相互作用机制的研究进展。通过研究发现,在大尺度上,净初级生产力是衡量城市发展对区域物流、能流影响的有效指标;在小尺度上,城市物流、能流过程和城市内部的景观结构、格局有很强的相关性。城市发展显著的改变了自然的栖息地及生物生长过程,本地植被种类减少,外来种增加,外来种的数量和人口数量有显著的相关性;而城市动物群落主要由一些小型哺乳动物、无脊椎动物、鸟类、两栖爬行类动物组成,其中,鸟类是研究城市化过程的有效指示物种。城市生态系统特有的景观格局及生态等过程显著的改了局部区域的微气候和水文过程,城市气温增加,风速降低,云、雾量增加,地表径流增加,流速加大,污染负荷增强等。因此,控制人类活动,优化土地利用的结构和空间格局,是改善城市生态系统结构和过程,保证可持续发展的基本出发点。但是,目前有关城市-格局-过程之间的影响机制还不十分清楚,尤其是定量研究较少。因此,结合传统的城市生态学,景观生态学的理论和其他相关学科领域的发展,为深入分析城市格局-过程之间的关系提供了重要的研究前景。  相似文献   

4.
The search for novel approaches to establishing ecological baselines (reference conditions) is constrained by the fact that most ecological studies span the past few decades, at most, and investigate ecosystems that have been substantially altered by human activities for decades, centuries, or more. Paleobiology, archeology, and history provide historical ecological context for biological conservation, remediation, and restoration. We argue that linking historical ecology explicitly with conservation can help unify related disciplines of conservation paleobiology, conservation archeobiology, and environmental history. Differences in the spatial and temporal resolution and extent (scale) of prehistoric, historic, and modern ecological data remain obstacles to integrating historical ecology and conservation biology, but the prolonged temporal extents of historical ecological data can help establish more complete baselines for restoration, document a historical range of ecological variability, and assist in determining desired future conditions. We used the eastern oyster (Crassostrea virginica) fishery of the Chesapeake Bay (U.S.A.) to demonstrate the utility of historical ecological data for elucidating oyster conservation and the need for an approach to conservation that transcends disciplinary boundaries. Historical ecological studies from the Chesapeake have documented dramatic declines (as much as 99%) in oyster abundance since the early to mid‐1800s, changes in oyster size in response to different nutrient levels from the sixteenth to nineteenth centuries, and substantial reductions in oyster accretion rates (from 10 mm/year to effectively 0 mm/year) from the Late Holocene to modern times. Better integration of different historical ecological data sets and increased collaboration between paleobiologists, geologists, archeologists, environmental historians, and ecologists to create standardized research designs and methodologies will help unify prehistoric, historic, and modern time perspectives on biological conservation. Integración de Paleobiología, Arqueología e Historia para Informar a la Biología de la Conservación  相似文献   

5.
Holyoak M  Loreau M 《Ecology》2006,87(6):1370-1377
Neutral community models embody the idea that individuals are ecologically equivalent, having equal fitness over all environmental conditions, and describe how the spatial dynamics and speciation of such individuals can produce a wide range of patterns of distribution, diversity, and abundance. Neutral models have been controversial, provoking a rush of tests and comments. The debate has been spurred by the suggestion that we should test mechanisms. However, the mechanisms and the spatial scales of interest have never clearly been described, and consequently, the tests have often been only peripherally relevant. At least two mechanisms are present in spatially structured neutral models. Dispersal limitation causes clumping of a species, which increases the strength of intraspecific competition and reduces the strength of interspecific competition. This may prolong coexistence and enhance local and regional diversity. Speciation is present in some neutral models and gives a donor-controlled input of new species, many of which remain rare or are short lived, but which directly add to species diversity. Spatial scale is an important consideration in neutral models. Ecological equivalence and equal fitness have implicit spatial scales because dispersal limitation and its emergent effects operate at population levels, and populations and communities are defined at a chosen spatial scale in recent neutral models; equality is measured relative to a metacommunity, and this necessitates defining the spatial scale of that metacommunity. Furthermore, dispersal has its own scales. Thorough empirical tests of neutral models will require both tests of mechanisms and pattern-producing ability, and will involve coupling theoretical models and experiments.  相似文献   

6.
Scientists have traditionally collected data on whether a population is increasing, decreasing, or staying the same, but such studies are often limited by geographic scale and time frame. This means that for many species, understanding of trends comes from only part of their ranges at particular periods. Working with citizen scientists has the potential to overcome these limits. Citizen science has the added benefit of exposing citizens to the scientific process and engaging them in management outcomes. We examined a different way of using citizen scientists (instead of data collection). We asked community members to answer a question directly and thus examined whether community wisdom can inform conservation. We reviewed the results of 3 mail‐in surveys that asked community members to say whether they thought koala populations were increasing, decreasing, or staying the same. We then compared the survey results with population trends derived from more traditional research. Population trends identified through community wisdom were similar to the trends identified by traditional research. The community wisdom surveys, however, allowed the question to be addressed at much broader geographical scales and time frames. Studies that apply community wisdom have the benefit of engaging a broad section of the community in conservation research and education and therefore in the political process of conserving species.  相似文献   

7.
Coexistence of the niche and neutral perspectives in community ecology   总被引:11,自引:0,他引:11  
Leibold MA  McPeek MA 《Ecology》2006,87(6):1399-1410
The neutral theory for community structure and biodiversity is dependent on the assumption that species are equivalent to each other in all important ecological respects. We explore what this concept of equivalence means in ecological communities, how such species may arise evolutionarily, and how the possibility of ecological equivalents relates to previous ideas about niche differentiation. We also show that the co-occurrence of ecologically similar or equivalent species is not incompatible with niche theory as has been supposed, because niche relations can sometimes favor coexistence of similar species. We argue that both evolutionary and ecological processes operate to promote the introduction and to sustain the persistence of ecologically similar and in many cases nearly equivalent species embedded in highly structured food webs. Future work should focus on synthesizing niche and neutral perspectives rather than dichotomously debating whether neutral or niche models provide better explanations for community structure and biodiversity.  相似文献   

8.
9.
土壤动物群落生态学与土壤微生态环境的关系   总被引:3,自引:0,他引:3  
主要综述了国内外蚯蚓种群、捕食性线虫、蚂蚁、跳虫、螨类等土壤动物与土壤理化性质的关系,以及蚯蚓、白蚁、蜗牛、线虫等土壤动物与土壤酶活性的相关性研究;提出了该学科今后的研究趋势。该学科未来要融合土壤动物和整个农林生态系统的研究为一体,把农林的土壤动物群落生态学及其与土壤微生态环境关系结合起来,耦合土壤动物与植物根系-根际微生态环境,链接农林土壤动物与土壤健康及其害虫生态调控,分析探究它们内在的联系和机制,加强立地调控措施,为森林健康和土壤健康提供科学基础资料。  相似文献   

10.
Climate, habitat, and species interactions are factors that control community properties (e.g., species richness, abundance) across various spatial scales. Usually, researchers study how a few properties are affected by one factor in isolation and at one scale. Hence, there are few multi-scale studies testing how multiple controlling factors simultaneously affect community properties at different scales. We ask whether climate, habitat structure, or insect resources at each of three spatial scales explains most of the variation in six community properties and which theory best explains the distribution of selected community properties across a rainfall gradient. We studied a Neotropical insectivorous bat ensemble in the Isthmus of Panama with acoustic monitoring techniques. Using climatological data, habitat surveys, and insect captures in a hierarchical sampling design we determined how much variation of the community properties was explained by the three factors employing two approaches for variance partitioning. Our results revealed that most of the variation in species richness, total abundance, and feeding activity occurred at the smallest spatial scale and was explained by habitat structure. In contrast, climate at large scales explained most of the variation in individual species' abundances. Although each species had an idiosyncratic response to the gradient, species richness peaked at intermediate levels of precipitation, whereas total abundance was very similar across sites, suggesting density compensation. All community properties responded in a different manner to the factor and scale under consideration.  相似文献   

11.
Barnes and Roderick developed a generic, theoretical framework for vegetation modeling across scales. Inclusion of a self-thinning mechanism connects the individual to the larger-scale population and, being based on the conservation of mass, all mass flux processes are integral to the formulation. Significantly, disturbance (both regular and stochastic) and its impact at larger scales are included in the formulation. The purpose of this paper is to illustrate how this model can be used to predict patch and ecosystem dry mass, and consequently system carbon. Examples from pine plantations and mixed forests are considered, with these applications requiring estimates of system carrying capacity and the growth rates of individual plants. The results indicate that the model is relatively simple and straightforward to apply, and its predictions compare well with the data. A significant feature of this approach is that the impact of local scale data on the dynamics of larger patch and ecosystem scales can be determined explicitly, as we show by example. Further, the general formulation has an analytic solution based on characteristics of the individual, facilitating practical and predictive application.  相似文献   

12.
K. F. Wishner 《Marine Biology》1980,60(2-3):179-187
Benthopelagic plankton was collected 10 to 100 m above the bottom of the deep sea (1100 to 3200 m) with an opening-closing net. Five samples were taken from the San Diego Trough, 2 from the eastern tropical Pacific and 2 from the northeast Atlantic. Roughly 80% of the individual organisms collected were copepods; the next most abundant groups were usually isopods, ostracods, and chaetognaths. Within the depth range studied, absolute abundances of most animal groups decreased with depth, but relative abundances (%) did not change. Of over 100 species of adult gymnopleid copepods collected, a few species were abundant, but most were rare. Copepod exoskeletons were more abundant than living copepods. For the gymnopleids, similarities among the 3 geographical regions were strong at the family and genus level but weak at the species level. Species that were widely distributed horizontally tended to occupy different positions (in terms of rank order of abundance) in each community. Gut content analysis indicated that the most abundant gymnopleids were generalized particle feeders. However, size-frequency distributions provided indirect evidence for niche separation. The deep-sea benthopelagic plankton was divisible into a truly planktonic component and a bottom-associated component. Abundances of some copepods changed relative to distance off the bottom. Several copepods and other animals, previously described as epibenthic or bottom-associated, were collected more that 10 m above the bottom and thus appeared to move freely between the bottom and lower water column.  相似文献   

13.
We examine the feeding ecology of characteristic micronekton species inhabiting the mid-slope region (~700 to 1,500 m depths) off southern Tasmania. Five fishes, Diaphus danae, Hygophum hanseni, Lampanyctus australis (Myctophidae), Phosichthys argenteus (Phosichthyidae) and Chauliodus sloani (Chauliodontidae), were sampled by depth-stratified midwater trawling on a diel and seasonal basis. Overall, 74 prey taxa were identified from 2,132 stomachs. Euphausiids (mostly Euphausia spinifera and E. similis) and calanoid copepods (mostly Pleuromamma species) were the main prey of the three myctophids; P. argenteus ate fishes and decapods in addition to the euphausiids, while C. sloani ate only fishes. Copepods were less important in the diets of larger D. danae, L. australis and P. argenteus and were replaced by euphausiids in the myctophids and by fishes in P. argenteus. In autumn, when euphausiid biomass increased six-fold, all three myctophids and P. argenteus fed most intensively and consumed a high proportion of euphausiids. The three myctophids appeared to feed nocturnally. Differences in the timing and duration of feeding corresponded to differences in their spatio-temporal overlap with key prey. Daily rations of H. hanseni (1.93% dry-weight biomass) and L. australis (1.43%), estimated from data on stomach fullness, were typical for temperate myctophids and higher than that of the non-migratory P. argenteus (0.43%). The vertical flux of near-surface plankton production to the mesopelagic food web is based primarily on diel feeding in the upper water column (<500 m) rather than consumption of species that migrate seasonally into the deeper mesopelagic zone. Because species such as P. argenteus and C. sloani feed above the third trophic level, their predators, including the commercially important orange roughy, are feeding between levels four and five.  相似文献   

14.
Perfecto I  Vandermeer J 《Ecology》2008,89(4):915-920
The coffee agroforestry system provides an ideal platform for the study of spatial ecology. The uniform pattern of the coffee plants and shade trees allows for the study of pattern generation through intrinsic biological forces rather than extrinsic habitat patchiness. Detailed studies, focusing on a key mutualism between an ant (Azteca instabilis) and a scale insect (Coccus viridis), conducted in a 45-ha plot in a coffee agroforestry system have provided insights into (1) the quantitative evaluation of spatial pattern of the scale insect Coccus viridis on coffee bushes, (2) the mechanisms for the generation of patterns through the combination of local satellite ant nest formation and regional control from natural enemies, and (3) the consequences of the spatial pattern for the stability of predator-prey (host-parasitoid) systems, for a key coccinelid beetle preying on the scale insects and a phorid fly parasitoid parasitizing the ant.  相似文献   

15.
Navarrete SA  Broitman BR  Menge BA 《Ecology》2008,89(5):1308-1322
Recruitment variation can be a major source of fluctuation in populations and communities, making it difficult to generalize results. Determining the scales of variation and whether spatial patterns in the supply of individuals are persistent over time can provide insight into spatial generality and the application of conservation and metacommunity models. We examined these issues using eight-year-long data sets of monthly recruitment of intertidal mussels (Mytilus spp., Perumytilus purpuratus, Semimytilus algosus, Brachidontes granulata) and barnacles (Balanus glandula, Chthamalus dalli, Jehlius cirratus, Notochthamalus scabrosus) at sites spanning > 900 km along the coasts of Oregon-northern California (OR-NCA, 45.47-39.43 degrees N) and central Chile (CC, 29.5-34.65 degrees S). We evaluated four general "null" hypotheses: that despite different phylogenies and great spatial separation of these taxa, their similar life history strategies and environmental settings lead to similar patterns of recruitment (1) between hemispheres, (2) in time, (3) in space, and (4) at larger and smaller spatial scales. Hypothesis 1 was rejected: along the OR-NCA coast, rates of recruitment were between two and three orders of magnitude higher, and patterns of seasonality were generally stronger and more coherent across space and time than along CC. Surprisingly, however, further analysis revealed regularities in both time and space for all species, supporting hypotheses 2 and 3. Temporal decorrelation scales were 1-3 months, and characteristic spatial scales of recruitment were approximately 250 km. Contrary to hypothesis 4, for the ecologically dominant species in both hemispheres, recruitment was remarkably persistent at larger mesoscales (kilometers) but was highly stochastic at smaller microscales (meters). Across species, increased recruitment variation at large scales was positively associated with increased persistence. Our results have several implications. Although the two regions span distinct latitudinal ranges, potential forcing processes behind these patterns include similar large-scale climates and topographically locked hydrographic features, such as upwelling. Further, spatial persistence of the recruitment patterns of most species at the mesoscale supports the view that marine protected areas can be powerful conservation and management tools. Finally, persistent and yet contrasting spatial patterns of recruitment among competing species suggest that recent metacommunity models might provide useful representations of the mechanisms involved in species coexistence.  相似文献   

16.
长江口南北支浮游动物群落生态学研究   总被引:7,自引:0,他引:7  
长江口特殊的生态环境使得浮游动物的种类组成、密度和时空分布等生态特征有别于其它水体。2005年秋季(丰水期)和2006年春季(枯水期)对长江口南北支浮游动物进行了2个航次的调查,沿南北支由西向东设立3个采样断面共20个采样点。共采集到浮游动物227种,其中轮虫65种,原生动物107种,枝角类15种,桡足类40种。优势种包括龟甲轮虫(Keratella)、刺簇多肢轮虫(Polyarthra trigla)、萼花臂尾轮虫(Brachionus calyciflorus)、砂壳虫(Difflugia)、表壳虫(Arcella)、砂壳纤毛虫(Tintinnid)、中华哲水蚤(Calanus sinicus)、汤匙华哲水蚤(Sinocalanus dorrii)、广布中剑水蚤(Mesocyclops leuckarti)、象鼻溞(Bosmina)等。文章对南北两支浮游动物的种类组成和结构进行了比较,南支浮游动物的种类、数量及生物多样都高于北支,南北两支的浮游动物群落相似度很低。南北两支水域环境的不同造成其浮游动物群落结构的较大差异,文章分析了环境因子与浮游动物群落结构的相关性,其中水温是重要的影响因素,水温的季节性决定了浮游动物在时间分布上的变化。盐度对浮游动物群落结构的影响主要决定了其物种生态类型及空间分布。从整体上看,南北支主要受长江径流控制,浮游动物的种类组成以淡水种为主,咸水种在断面3出现较多。  相似文献   

17.
长江口南北支浮游动物群落生态学研究   总被引:1,自引:0,他引:1  
长江口特殊的生态环境使得浮游动物的种类组成、密度和时空分布等生态特征有别于其它水体。2005年秋季(丰水期)和2006年春季(枯水期)对长江口南北支浮游动物进行了2个航次的调查,沿南北支由西向东设立3个采样断面共20个采样点。共采集到浮游动物227种,其中轮虫65种,原生动物107种,枝角类15种,桡足类40种。优势种包括龟甲轮虫(Keratella)、刺簇多肢轮虫(Polyarthra trigla)、萼花臂尾轮虫(Brachionus calyciflorus)、砂壳虫(Difflugia)、表壳虫(Arcella)、砂壳纤毛虫(Tintinnid)、中华哲水蚤(Calanus sinicus)、汤匙华哲水蚤(Sinocalanus dorrii)、广布中剑水蚤(Mesocyclops leuckarti)、象鼻溞(Bosmina)等。文章对南北两支浮游动物的种类组成和结构进行了比较,南支浮游动物的种类、数量及生物多样都高于北支,南北两支的浮游动物群落相似度很低。南北两支水域环境的不同造成其浮游动物群落结构的较大差异,文章分析了环境因子与浮游动物群落结构的相关性,其中水温是重要的影响因素,水温的季节性决定...  相似文献   

18.
The boundaries as well as the macro-epibenthic biomass distribution and composition of a North Adriatic benthic community, dominated by the brittle star Ophiothrix quinquemaculata (D.Ch.), the sponges Reniera ssp., and the ascidians Microcosmus ssp. were determined. Transects totalling more than 80 km (i.e., a recorded area of approximately 150 000 m2) were taken by means of a combined TV- and photocamera sled. The observations, TV-recordings, and photos, together with 392 diver-collected quantitative samples were evaluated. The biomass values were used to establish isobenths. Within the community, the mean biomass, measured as wet weight, amounted to 370 (±73) g/m2 with maxima of more than 1000 g/m2. 64% of the biomass was due to the designating group Ophiothrix-Reniera-Micrcosmus, 87.5% were represented by filter- and suspension-feeding species alone. The mean biomass in the peripheral areas was evaluated at 166 (±62) g/m2. Biomass distribution and composition is examined, and the ecological function and meaning of the observed patterns is discussed.This investigation was carried out within the frame of a joint programme between the Lehrkanzel für Meeresbiologie, University of Vienna, and the Marine Biological Station, Portoroz, University of Ljubljana.  相似文献   

19.
SUMMARY

Rapid urbanisation and serious environmental problems have led people worldwide to realise the significance of urban planning and management towards a sustainable environment. Beijing was used as a case study to develop a framework and strategies for sustainable development using ecological principles. At the regional level, Beijing-Tianjin agglomeration and Hebei Province are considered together. At the Beijing administrative level, some important measures are put forward for revision of the Beijing Urban Master Plan. At the Beijing plain level, the future spatial structure of Beijing city and the relationship between settlements, green space and transportation are considered, and three basic development patterns are proposed. At the inner district level, the ecological corridor system is suggested, based on ecosystem services. At the selected area level, a comprehensive strategy and key measures for conservation and renewal of old Beijing city core are provided. Once strategies for Beijing urban development are implemented step-by-step, a vision for future development can be achieved. This paper provides considerations for improvement of urban planning and management in China and other countries.  相似文献   

20.
Wesner JS  Billman EJ  Belk MC 《Ecology》2012,93(7):1674-1682
Models of habitat selection often assume that organisms choose habitats based on their intrinsic quality, regardless of the position of these habitats relative to low-quality habitats in the landscape. We created a habitat matrix in which high-quality (predator-free) aquatic habitat patches were positioned adjacent to (predator-associated) or isolated from (control) patches with single or two species of caged predators. After 16 days of colonization, larval insect abundance was reduced by 50% on average in both the predator and predator-associated treatments relative to isolated controls. Effects were largely similar among predator treatments despite variation in number of predator species, predator biomass, and whether predators were native or nonnative. Importantly, the strength of effects did not depend on whether predators were physically present. These results demonstrate that predator cues can cascade with equal strength across ecological boundaries, indirectly altering community assembly via habitat selection in intrinsically high-quality habitats.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号