首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到19条相似文献,搜索用时 46 毫秒
1.
土壤动物粒径谱研究进展   总被引:1,自引:0,他引:1  
徐国瑞  马克明 《生态学报》2017,37(8):2506-2519
群落结构如何响应环境变化是生态学研究长期关注的核心问题之一。粒径谱由个体大小和多度构建而来,与营养级转换速率相关、反映生态系统过程动态以及表征生态系统稳定性,可以将其视为一个综合的功能多样性指标用于预测和表征群落的组成以及生态系统功能如何响应环境压力。粒径谱研究最初始于水生生态系统,近年来被引入到土壤动物群落生态学的研究中。简要回顾粒径谱的概念由来及理论基础,分析比较了当前粒径谱研究中的4种易混淆类型,介绍了常用的两类土壤动物粒径谱构建方法及其生态学意义,梳理了土壤动物粒径谱对环境梯度响应与生态化学计量学相结合的研究进展,并指出了应用粒径谱研究土壤动物群落的难点及限制条件。未来,在基础理论研究方面,土壤动物粒径谱应关注个体大小与营养级位置及能量利用关系;在应用方面,土壤动物粒径谱可结合传统的分类方法广泛应用于指示环境污染、生态恢复、保育生物以及土地利用变化等。  相似文献   

2.
河口及近岸海域环境复杂,浮游生物反馈调节频繁,粒径结构极不稳定.本文对辽宁近岸河口区和港口区浑浊带海域的浮游生物粒径结构进行研究.结果表明:在无机氮含量高的浑浊带海域,浮游植物生物量主要集中在20 μm<ESD(等效球径,equivalent sphere diameter) <100μm小粒径区域;而在低营养盐的清洁海域,浮游植物生物量主要集中在ESD>100 μm大粒径区域.表明浮游植物群落对高浓度悬浮物的响应可能通过小粒径生物进行反馈调节,使圆筛藻(Coscinodiscus sp.)等大粒径浮游植物生物量组成降低,将影响以摄食这些饵料为主的各种鱼虾幼体资源量.另外,本文构建了标准生物量谱,它符合北方近岸浅海、富营养化水域生态系统的特征,谱线斜率表明,研究海域浮游生物群落的生物量随着粒级的增加而逐渐增大.探讨了甲藻和枝角类作为评估悬浮物污染的指示生物的可行性.  相似文献   

3.
紫外辐射对陆生植物的生物学效应已被广泛研究,对水生生物也能产生一系列影响。本文在综述国内外紫外线在水体中渗透状况及影响因素的基础上,阐述了紫外辐射对浮游细菌和微型浮游生物、浮游植物、浮游动物、大型藻类、鱼卵和幼鱼、鱼类及两栖动物的生物学效应,从直接效应和间接效应两方面介绍了紫外辐射对水生生物作用的机理。未来研究应该注重紫外辐射与气候变化、酸沉降、水污染等环境因子联合作用对水生有机体产生影响,其研究对象应扩展至沉水植物、底栖生物等大部分水生有机体,这些研究将对深入研究水生生态系统的演化、水生生态系统退化及其修复起重要作用。  相似文献   

4.
春季长江口邻近外海网采浮游生物的生物量谱   总被引:6,自引:0,他引:6  
左涛  王俊  金显仕  李忠义  唐启升 《生态学报》2008,28(3):1174-1182
对2005年春季黄海南部、东海北部近江口外海水域网采的浮游生物个体大小的粒径分布进行研究,确定各粒级大小的功能群组成,建立此季该调查水域网采浮游生物的生物量谱.样品是用小、中、大型浮游生物网(网孔径为77、160、 505μm)采集所得.三网具采集浮游生物个体大小粒径是连续的,其中浮游植物,其等效粒径(ESD)和含碳量范围分别为5~250μm、15pg~146ng;浮游动物,含碳量范围为115ng~7.5mg,ESD分别为120μm~5.8mm、200μm~2cm.所得网采浮游生物的标准生物量谱,总测区的斜率为-0.607±0.059、截距为19.45±0.46;各站位的生物量谱斜率为-0.889~-0.455、截距为12.866~16.863,两特征参数分布规律为南高北低,且具有显著的站位间差异.相关性分析表明截距和回归系数与粒级多样性有关.  相似文献   

5.
流式细胞术在水体微型生物研究中的应用   总被引:1,自引:0,他引:1  
综述了流式细胞术(flow cytometry)在水体微型生物研究中的应用。包括微型生物的识别、记数和生物量研究,微型生物的细胞周期分析以及生态与生理学研究。讨论了FCM在淡水微型生物和环境生物学中的应用。FCM技术与食品的改进将促进水体微型生物的研究,从而有助于对水生生态系统的深入认识。  相似文献   

6.
海洋微型底栖生物的多样性与地理分布   总被引:2,自引:0,他引:2  
海洋微型底栖生物是指生活于海洋沉积物中及表面的所有单细胞原核和真核微型生物,包括原核微生物、真核微藻及原生动物等光合自养和异养的类群.与水体相比,海洋底栖生境孕育了形态和功能多样性更高的微型生物,在陆架浅海单位体积沉积物中其丰度较之水体中同类生物高一至几个数量级,而深海则孕育着特殊进化环境下新奇多样且数量庞大的微型底栖生物,是维持海洋生物多样性、海洋生态系统结构和功能不可或缺的部分.迄今对于微型生物是全球性还是限定性分布一直存在争议,对其解答受到分类研究欠缺及采样不足的制约.分子生物学从正反两方面提供了理论依据,但无法得出一个普遍接受的观点.海洋微型底栖生物的多样性研究侧重于物种多样性及群落结构与分子多样性,较为显著的进展体现在原核微生物的分子多样性及底栖真核微藻的物种多样性研究,对于海洋底栖原生动物的多样性研究则相较滞后.本文综述了国内外对海洋微型底栖生物各主要类群的分类学和多样性研究进展,探讨了各类群在全球的潜在物种多样性,并就我国未来加强海洋微型底栖生物多样性构成、分布与变动及驱动变化的因子以及底栖微食物网的研究提出了建议.  相似文献   

7.
覃光球  卢豪良  唐振柱  赵鹏  白雪涛  彭亮 《生态学报》2014,34(10):2481-2489
捕食信息素是捕食者释放的,能够引发猎物反捕食反应的化学信号。在水生生态系统中,捕食信息素在捕食者和猎物之间信息传递及协同进化过程中发挥着重要的作用,其生态学效应在国际上受到广泛关注。捕食信息素的来源有多种形式,研究中常使用养殖过捕食者的水溶液作为捕食信息素的来源。捕食信息素的作用效果受到捕食者和猎物的种类、信息素的浓度、观察的指标等多方面因素的影响。捕食信息素可以对水生生物的行为、形态和生活史特征等方面造成影响。水生生物通过感知捕食信息素来提前预知潜在的被捕食风险,并作出适应性调整,以降低被捕食的风险。在某些情况下,捕食信息素可以与污染物产生交互作用,从而干扰污染物对水生生物的毒性。对水生环境中捕食信息素的研究现状做了综述,介绍了当前对捕食信息素来源和理化性质等本质问题的认识,总结捕食信息素对水生生物行为、形态和生活史特征的影响,以及捕食信息素对污染物毒性的干扰,并分析了这一研究领域尚存在的困难和今后的研究方向。加强对捕食信息素的研究,将为解析水生环境中捕食者和猎物的生态关系提供新依据。  相似文献   

8.
微型浮游生物生态学研究概述   总被引:14,自引:2,他引:12  
孙书存  陆健健 《生态学报》2001,21(2):302-308
最近一二十年来,原绿藻和微食物网的重大发现已使人们充分认识到微型浮游生物在水域生态系统的养分循环和能量流动中的重要意义,也为微型浮游生物的研究提出了新的方向。对微型浮游生物的主要类群,即微型浮游植物、异养细菌和微型浮游动物的生态学研究进展作了概述,在此基础上讨论了类群间的生态关系和微食物网的研究动向。最后对微型游生物生态学的继续研究提出了几点看法。  相似文献   

9.
为了解乐清湾贝类资源情况及群落稳定性特征,基于2016—2017年乐清湾定点调查数据,分析了不同季节乐清湾贝类组成、优势种、资源密度、以及物种多样性,并首次建立乐清湾海域贝类生物量粒径谱与标准化生物量粒径谱。结果显示:1)本次共采集到贝类共计45种,隶属于12目,25科,31属。焦河蓝蛤(Potamocorbula ustulata)为乐清湾绝对优势种;2)资源密度表现为夏季最高,其次为春季,秋季与冬季次之;4个季节的丰富度指数(D)、多样性指数(H′)和均匀度指数(J′)平均为3.26、1.61、0.45,3种多样性指数均处于较低水平;3)ABC曲线显示乐清湾贝类的生物群落处于中度干扰状态;4)乐清湾生物量粒径谱谱型复杂,优势种控制着生物量粒径谱的峰值,且与我国其他海域的结果也存在差异;5)标准化生物量粒径谱的斜率范围为-1.5539—-0.7373,在我国近海海域中属于偏低水平,表明营养循环水平较低。截距范围在16.673—21.597,高于我国其他海域,说明乐清湾贝类生产力水平较高。  相似文献   

10.
生物个体的生物学特征(新陈代谢速率等)与个体大小(体积和生物量等)的依赖性关系称为异速生长关系,这种关系经过尺度转换之后,还影响着种群、群落和生态系统等。海洋环境较为复杂,浮游生物的代谢速率不仅受到个体大小影响,同时光照、温度和营养物质也是重要的影响因素,因此3/4规律只有在理想环境状况下才能实现。对于大多数浮游生物来讲,其尺度因子并非单一的,存在着多元尺度指数。由于单一和多元尺度指数都忽略了环境温度的影响,生态学代谢理论在考虑个体大小的基础上,加上温度这个参数后能够解释不同层次的生态学过程。在综述了异速生长关系发展历史的基础上,着重探讨了该关系在浮游生物中的研究进展。  相似文献   

11.
Zuo T  Wang J  Jin X S  Li Z Y  Tang Q S 《农业工程》2008,28(3):1174-1182
Based on data from survey carried out in spring 2005, the biomass size spectra of net plankton were explored in the adjacent sea of Yangtze River Estuary. Results revealed an approximately continuous size distribution of plankton individuals, from phytoplankton (5–250 μm cell?1 in equivalent sphere diameter (ESD), 15 pg–146 ng C cell?1) to zooplankton (120 μm–2 cm ESD, 115 ng–7.5 mg C ind?1). The normalized spectra (carbon scale) were linear with slope ranged from –0.889 to –0.445, and intercept ranged from 12.866 to 16.863 (all stations together, slope = –0.606, intercept = 19.448), indicating strong deviations from the ideal value (slope = –1.22) of a steady pelagic ecosystem. Correlation analysis presented that intercept and regression coefficient of net plankton size spectra had significant relationship with plankton biomass size diversity.  相似文献   

12.
Based on data from survey carried out in spring 2005, the biomass size spectra of net plankton were explored in the adjacent sea of Yangtze River Estuary. Results revealed an approximately continuous size distribution of plankton individuals, from phytoplankton (5–250 μm cell?1 in equivalent sphere diameter (ESD), 15 pg–146 ng C cell?1) to zooplankton (120 μm–2 cm ESD, 115 ng–7.5 mg C ind?1). The normalized spectra (carbon scale) were linear with slope ranged from –0.889 to –0.445, and intercept ranged from 12.866 to 16.863 (all stations together, slope = –0.606, intercept = 19.448), indicating strong deviations from the ideal value (slope = –1.22) of a steady pelagic ecosystem. Correlation analysis presented that intercept and regression coefficient of net plankton size spectra had significant relationship with plankton biomass size diversity.  相似文献   

13.
Synopsis Instantaneous feeding, assimilation, and growth rates for white sucker larvae and young common shiners and guppies (1–2 mg initial dry weight) were measured. Food consisted of natural zooplankton. Linear relationships were obtained between growth and feeding rates for instantaneous feeding rates up to 0.5 mg-1 day-1. Maximum gross conversion efficiencies (K1) were 0.26, 0.31, and 0.24 for suckers, shiners, and guppies respectively. Particle-size-conversion efficiency (-log K1 per log predator-prey size ratio) was 0.15 for suckers, 0.14 for shiners, and 0.18 for guppies. These values are lower than most available estimates of particle-size-conversion efficiency for carnivorous zooplankton and piscivorous fish, indicating that young planktivorous fish are among the most efficient predators at transferring biomass up the biomass size spectrum in aquatic ecosystems.  相似文献   

14.
Food web structure and dynamics depend on relationships between body sizes of predators and their prey. Species‐based and community‐wide estimates of preferred and realized predator–prey mass ratios (PPMR) are required inputs to size‐based size spectrum models of marine communities, food webs, and ecosystems. Here, we clarify differences between PPMR definitions in different size spectrum models, in particular differences between PPMR measurements weighting prey abundance in individual predators by biomass (rbio) and numbers (rnum). We argue that the former weighting generates PPMR as usually conceptualized in equilibrium (static) size spectrum models while the latter usually applies to dynamic models. We use diet information from 170,689 individuals of 34 species of fish in Alaskan marine ecosystems to calculate both PPMR metrics. Using hierarchical models, we examine how explained variance in these metrics changed with predator body size, predator taxonomic resolution, and spatial resolution. In the hierarchical analysis, variance in both metrics emerged primarily at the species level and substantially less variance was associated with other (higher) taxonomic levels or with spatial resolution. This suggests that changes in species composition are the main drivers of community‐wide mean PPMR. At all levels of analysis, relationships between weighted mean rbio or weighted mean rnum and predator mass tended to be dome‐shaped. Weighted mean rnum values, for species and community‐wide, were approximately an order of magnitude higher than weighted mean rbio, reflecting the consistent numeric dominance of small prey in predator diets. As well as increasing understanding of the drivers of variation in PPMR and providing estimates of PPMR in the north Pacific Ocean, our results demonstrate that that rbio or rnum, as well as their corresponding weighted means for any defined group of predators, are not directly substitutable. When developing equilibrium size‐based models based on bulk energy flux or comparing PPMR estimates derived from the relationship between body mass and trophic level with those based on diet analysis, weighted mean rbio is a more appropriate measure of PPMR. When calibrating preference PPMR in dynamic size spectrum models then weighted mean rnum will be a more appropriate measure of PPMR.  相似文献   

15.
湛江高桥红树林湿地底栖动物粒径谱   总被引:1,自引:0,他引:1  
在我国,红树林湿地底栖动物粒径谱研究很少。根据2010年1月、4月、7月、10月在湛江高桥红树林湿地获得的大型和小型底栖动物数据,构建了底栖动物生物量粒径谱,以期为湛江高桥红树林湿地的生态保护和持续利用提供科学依据。主要研究结果如下:(1)高桥红树林湿地生物量粒径谱基本为3峰模式。第一峰在-2粒级,主要由线虫构成;第二峰在4—12粒级,主要由寡毛类、多毛类和小个体甲壳类构成;第三峰在13—22粒级,主要由大个体腹足类、双壳类和甲壳类构成。(2)木榄、桐花树和无瓣海桑生境在0—4粒级之间出现一个明显的波谷,这个波谷介于线虫和寡毛类之间,是大型与小型底栖动物粒级交汇区。(3)高桥红树林湿地底栖动物正态化生物量粒径谱的斜率大于-1,截距为16.533—18.150。桐花树(Aegiceras corniculatum)和无瓣海桑(Sonneratia apetala)生境的截距、最小粒级的生物量(BMS)高于木榄(Bruguiera gymnorrhiza)和盐地鼠尾粟(Sporobolus virginicus)生境,说明桐花树和无瓣海桑生境的底栖动物生产力水平较木榄和盐地鼠尾粟生境的高;秋季的截距、BMS较其他季节高,说明秋季的底栖动物生产力水平较其他季节高。  相似文献   

16.
A new time-dependent continuous model of biomass size spectra is developed. In this model, predation is the single process governing the energy flow in the ecosystem, as it causes both growth and mortality. The ratio of predator to prey is assumed to be distributed: predators may feed on a range of prey sizes. Under these assumptions, it is shown that linear size spectra are stationary solutions of the model. Exploited fish communities are simulated by adding fishing mortality to the model: it is found that realistic fishing should affect the curvature and stability of the size spectrum rather than its slope.  相似文献   

17.
The reproductive strategy of most fishes is to produce a large number of tiny eggs, leading to a huge difference between egg size and asymptotic body size. The viability of this strategy is examined by calculating the life-time reproductive success R0 as a function of the asymptotic body size. A simple criterion for the optimality of producing small eggs is found, depending on the rate of predation relative to the specific rate of consumption. Secondly it is shown that the success of the reproductive strategy is increasing with asymptotic body size. Finally the existence of both upper and lower limits on the allowed asymptotic sizes is demonstrated. A metabolic upper limit to asymptotic body size for all higher animals is derived.  相似文献   

18.
19.
The largest perturbation on upper trophic levels of many marine ecosystems stems from fishing. The reaction of the ecosystem goes beyond the trophic levels directly targeted by the fishery. This reaction has been described either as a change in slope of the overall size spectrum or as a trophic cascade triggered by the removal of top predators. Here we use a novel size- and trait-based model to explore how marine ecosystems might react to perturbations from different types of fishing pressure. The model explicitly resolves the whole life history of fish, from larvae to adults. The results show that fishing does not change the overall slope of the size spectrum, but depletes the largest individuals and induces trophic cascades. A trophic cascade can propagate both up and down in trophic levels driven by a combination of changes in predation mortality and food limitation. The cascade is damped as it comes further away from the perturbed trophic level. Fishing on several trophic levels leads to a disappearance of the signature of the trophic cascade. Differences in fishing patterns among ecosystems might influence whether a trophic cascade is observed.  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