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1.
大兴安岭森林草原过渡带白桦及主要草本植物生态位关系的研究 总被引:10,自引:3,他引:10
以白桦、日阴菅及其它主要草本植物的个体数量为指标,分析了各植物种群在土壤有机质,速效P和pH值3个资源维上的生态位宽度和生态位重叠及其在不同海拔条件下的变化规律。日阴菅生态位宽度随海拔升高而增大,其余植物种类在有机质资源维上的生态位宽度,大都是以中等海拔(800m)的样带最宽,而在速效P资源维上,又以中等海拔的样带为最窄,由于高海拔及相应低气温在某种程度上限制了植物种群在土壤有机质和速效P的利用,主要植物种对之间在这两个资源维上的生态位重叠以高海拔(950m)样带为最小,在土壤pH值资源维上,溪荪与其它主要植物种间的生态位重叠皆以低海拔(650m)样带为最小,可能是其特殊的环境组合迫使溪荪发生了生态位移动,大多数种对在土壤有机质,速效P和pH值3个资源维上都以海拔800m的样带生态位重叠最大。 相似文献
2.
本文采用Shannon—Wiener和Pianka公式,在土壤水分、土壤含盐量和土壤有机质含量三维生态因子梯度上测定了松嫩草原碱化羊草草地放牧演替系列12种主要植物种群的生态位宽度和生态位重叠。结果表明,植物种群长期适应由放牧引起的群落和土壤环境因子梯度变化是种群生态位分化的主要原因。优势种羊草种群生态位宽度最大,三维上生态位宽度分别为0.910、0.869和0.930。五脉山黧豆和湿生植物生态位宽度均很窄。增加种表现出较强的适应环境能力,生态位宽度都较大。在放牧演替的先锋植物中,只有虎尾草生态位宽度较大(三维上平均0.707),角碱蓬和星星草种群生态位宽度均很窄。生态位宽度较大的物种与其它种群间生态位重叠较大。分布于相同或相邻放牧阶段及具有相同或相似环境要求的物种间生态位重叠较大。放牧条件下,羊草群落的演替过程也就是种群生态位分化的过程。 相似文献
3.
Abstract A study was conducted in a typical steppe area in central Inner Mongolia to determine resource utilization in time, space, and food by grasshopper assemblages. Pattern of use for these resources was analyzed from three vegetation types by examining species-specific niche breadths, overlaps and partitions of resource utilization as well as population sizes. Popular niche indices and the principal components analysis (PCA) procedure were used to indicate the interrelations among grasshopper species. In the heterogeneous grassland environments resulting from livestock grazing, eleven grasshopper species were categorized respectively based on the 3-dimensional niche segregation and overlap degree. Population sizes were determined by the calorific values of their realized population biomass. Comparison in niche breadth displayed that species which had a broad niche along one dimension at least had a narrow niche along another one. There were sufficient differences between species for overall overlap associated with resource use to explain coexistence in the assemblages by resource segregation. Distinct rule of niche complementarity in overlap was not found. Evidence from this study implied that the species-specific use of resource may be due primarily to grasshopper adaptive differentiation and to coevolutionary interactions between grasshopper and plant rather than interspecific competition among grasshopper species. 相似文献
4.
本文研究了内蒙古典型草原蝗虫在时间、空间和食物资源利用方面的特点。对于这些资源利用的格局是通过对存在于三种类型植被中蝗虫种的生态位宽度、资源利用的分化和重叠以及每种蝗虫的种群大小来分析的。常用的生态位指数和主成份分析技术用来阐明蝗虫种间的关系。在放牧形成的异质性草原环境中,11种蝗虫根据它们在三维生态位方面的分化和重叠程度被划分成数个种组。种群的大小是根据种群实际生物量所含热能值来确定的。生态位宽度比较说明,在某一维生态位宽的种,在另一维上必定变窄。生态位重叠的差异说明共存的蝗虫种在资源利用上的分化。生态位重叠的补偿规律在本项研究中并不明显。本项研究结果说明,蝗虫种资源利用的分化主要归因于蝗虫的适应性分化和蝗虫——植物协同进化的相互作用关系,而不是蝗虫种间竞争所造成的。 相似文献
5.
塔里木河中游植物种群在四种环境梯度上的生态位特征 总被引:31,自引:3,他引:28
分析了塔里木河中游19种植物在土壤含水量、土壤有机质、土壤pH值和土壤总含盐量各资源维上的生态位宽度和生态位重叠。结果表明,按照各资源维上生态位宽度平均值的大小可把19种植物分成3类,第一类群的物种是该流域植物群落中的建群种,对荒漠河岸环境有良好的适应性;第二类群的物种对环境资源的利用能力较弱于第一类群的物种;第三类群的物种中,大部分植物对流域环境的生态适应性较弱.但个别植物生态位宽度变窄有其特定的原因.从4个资源维、19种植物生态位重叠指数的变化上可以看出。该地区物种在一定程度上对环境资源需求分化或者物种的生态位发生位移,致使种对间生态位重叠程度降低,而土壤水和土壤盐分则是许多物种的限制因子。 相似文献
6.
新疆阜康绿洲荒漠过渡带主要植物种的生态位分析 总被引:22,自引:4,他引:22
采用Levins公式和王刚生态重叠计测方法,对新疆阜康绿洲荒漠过渡带中的7个植物种,分别从群落梯度和3个单一生态因子(土壤水分维,土壤盐分维,土壤酸碱度维)上对其生态位分化进行了定量分析。结果如下:(1)在群落梯度上,生态位大小依次为红砂(0.7010),梭梭(0.6434),角果藜(0.4774),雾冰藜(0.3745),盐爪爪(0.3541),叉毛蓬(0.3354)和碱蓬(0.2769);(2)红砂在土壤水分、土壤盐分、土壤酸碱度维上的生态位分别为0.5274,0.6039和0.3620,梭梭在这3维上分别为03320,0.3083和0.5103,从生态位宽度看,红砂和梭梭处于优势种地位,其余为非优势种;(3)每个物种在群落梯度上的生态位宽度基本大于在上述3个资源轴上的平均生态位;(4)红砂与梭梭在土壤盐分维上的生态位重叠最大(0.4203)。表明了这两个优势种在利用土壤盐分方面有相似的特性。 相似文献
7.
本文利用Levins和Pianka公式,在多维生态因子梯度上测定了海北地区高寒草甸三种嵩草(Kobresia)群落中若干植物种的生态位宽度和生态位重叠。结果表明:三种嵩草群落中优势种群的生态位宽度都较大,其中小嵩草(K,pygmaea)在土壤水势、光照强度和坡向等三维因子上的生态位宽度分别是0.918、0.896和0.910;矮嵩草(K.humilis)和藏嵩草(K.tibetica)在土壤水势维上的生态位宽度分别是0.875和0.866;植物种如具有较大的生态位,则种间的生态位重叠亦较高;植物种对间若有相似的生物学—生态学特征,生态位重叠有降低的趋势;小嵩草和矮嵩草在三维上的重叠值分别是0.671、0.719和0.686;某些杂类草与优质牧草之间存有较大的重叠,这主要与长期过度放牧、优良牧草受到抑制以及生境退化有关。 相似文献
8.
关帝山神尾沟优势种生态位分析 总被引:27,自引:0,他引:27
采用Shannon-Wiener生态位宽度公式和Petraitis生态位重叠指数测定了关帝山神尾沟8种主要乔木、18种主要灌木和42种主要草本种群的生态位宽度和生态位重叠,并对生态位定度和生态位重叠的关系进行了初步的探讨。结果表明,种群生态位定度越大,对环境的适应能力越强;具有相同或相似环境要求的物种间生态位重叠较大,生态位宽度较大的物种与其它种间生态位重叠较大。 相似文献
9.
太行山中段植物群落优势种生态位研究 总被引:18,自引:2,他引:16
运用TWINSPAN把样方分为8个群落类型,用Levins、Shannon-wiener生态位宽度公式和Petraitis生态位特定重叠指数公式测定群落中主要种群生态位宽度和生态位重叠,并分析各种群生态位的生态学意义。在总群落中,披针苔草和草地早熟禾的生态位宽度最大,说明它们对群落环境的适应能力最强,对资源的利用能力也最强;在不同的群落里(群落Ⅰ到群落Ⅷ),相同种群生态位宽度有极大差别,草地早熟禾在群落Ⅱ中,B1为 2.753,B2为 15.561,在群落Ⅷ中,B1为0,B2为1;总群落中,各种群的生态位宽度明显大于其在其他群落里的生态位宽度。两个种群的生态位重叠值越大,说明它们占据越相似的资源空间,珠芽蓼和火绒草的生态位重叠值高达0.892(群落Ⅰ中),说明它们利用资源的相似性程度很高;在总群落中,各种群之间生态位重叠值都很低。 相似文献
10.
皇甫川流域天然草地恢复演替进程中优势种的生态位分析 总被引:1,自引:0,他引:1
采用Levins,Shannon-Wiener生态位宽度公式和Levins生态位特定重叠指数公式对皇甫川流域天然草地恢复演替不同阶段植物群落中优势种生态位宽度和生态位重叠进行了测定,并分析各种群生态位宽度和生态位重叠的生态学意义。结果表明:演替过程中每一群落类型的优势种具有最大的生态位宽度;生态位宽度在演替序列的动态变化与种群动态有较好的对应关系;生态位重叠越大,种群间的生态相似性越大,利用资源的相似性程度越高,种间竞争可能越激烈;竞争是促使流域内各植物群落向顶级群落演替的一种动力机制。 相似文献
11.
宝天曼落叶阔叶林种群生态位特征 总被引:62,自引:9,他引:62
利用Levins、Hurlbert生态位宽度公式和Pianka生态位重叠公式测定了宝天曼落叶阔叶林14种主要乔木和22种主要灌木种群的生态位宽度和生态位重叠,并对生态位宽度、生态位重叠以及种间联结性的关系进行了初步探讨.结果表明,群落中主要优势种群的生态位宽度较大,乔木层主要优势种锐齿栎和漆树的Levins和Hurlbert生态位宽度分别为18.527、7.488和0.889、0.680,灌木层主要优势种哥兰叶、山葡萄和胡枝子的Levins和Hurlbert生态位宽度分别为18.964、14.479、13.251和0.908、0.799、0.785.具有相同或相似环境要求的物种间生态位重叠较大,生态位宽度较大的物种与其它种群间的生态位重叠较大.种间正联结性越强,其生态位重叠值越大,种间负联结性越强,其生态位重叠值越小. 相似文献
12.
南京市春季外来杂草调查及生态位研究 总被引:28,自引:5,他引:23
利用样方法调查了南京市不同生境下外来杂草的种类、盖度、密度情况,探讨了不同生境中外来杂草对杂草群落的影响,同时分析了10种主要外来杂草和本地伴生种的生态位特点.结果表明,南京市春季外来杂草有36种,在74个样点中外来杂草出现的频率达到98.65%;外来杂草的入侵对生物多样性有不利影响;外来杂草平均优势度在不同生境中大小次序为:水边>菜地>荒地>路旁>景区>田埂>草坪>果茶园>墙缝>农田>宅旁>山坡.生态位的研究结果表明:野塘蒿 Conyzabonariensis L. Cronq. 、野老鹳草 GeraniumcarolinianumL. 和阿拉伯婆婆纳 VeronicapersicaPoir. 是生态位宽度最高的外来杂草,其入侵性最强;具有较高生态位宽度的外来杂草与其它杂草的生态位重叠较大,具有相似形态特征的杂草间的生态位重叠较大. 相似文献
13.
汾河水库及河道中优势硅藻生态位的研究 总被引:14,自引:1,他引:14
采用Levins生态位宽度公式和Petrailis生态位特定重叠指数测定了汾河水库和河道中 5 0个主要硅藻种的生态位宽度和生态位重叠 ,并对生态位宽度和生态位重叠的关系进行了初步探讨 ,结果表明 ,着生硅藻中的原子舟形藻、眼斑小环藻、平卧桥弯藻、尖菱形藻、短小舟形藻、线形曲壳藻、阿尔夫舟形藻等生态位最大 ,浮游硅藻中 ,以具星小环藻、团聚小环藻、眼斑小环藻生态位最宽 ;同时表明 ,生态位宽度大的种与其它种的生态位重叠也较大。生态位重叠表明 ,着生硅藻中 ,生态位重叠普遍偏高 ,河道中 ,清洁水体指示种普通等片藻进攻性最强 ,水库中以α -中污和 β-中污带生物比索曲壳藻进攻性最高。从生态位普遍重叠指数分析 ,浮游硅藻明显小于着生硅藻 ,表明浮游生境下 ,硅藻分化明显 ,着生环境中 ,硅藻对资源利用充分 相似文献
14.
Shiro Kobayashi 《Population Ecology》1991,33(2):345-360
In six different environments of the Towada-Hachimantai National Park, the forest floor coleopterons were sampled by means of pitfall traps with five different baits. Their niche breadths and niche overlaps were assessed for the electivity of habitat, bait, and habitat × bait, and compared with those expected from neutral models constructed randomly. The niche breadths in the observed assemblages were smaller than those expected from the neutral model, while the niche overlaps were more widely distributed than those expected from the neutral model. Mean overlaps between species neighbors in niche space, cluster analyses, and ordinations of species revealed a guild for habitat, bait and habitat × bait. Lawlor's (1979) gamma matrices concerning the habitat electivity show that the rates of mutualism resulted from indirect interspecific competitions are significantly smaller in the guild than in the whole assemblage. This suggests that the interspecific competition among the guild members is mitigated or even converted into mutualism by joining of the species which do not belong to the guild. The rates of mutualism were also significantly larger in the resource state of two dimensions (habitat × bait) than in that of either one. Therefore, if niche overlaps are measured on the basis of resource state of multi-dimensions, the rates of mutualism may increase further. 相似文献
15.
转双抗虫基因741杨节肢动物群落营养结构及生态位变化 总被引:1,自引:0,他引:1
转双抗虫基因741杨(简称转基因741杨)节肢动物群落中,基位物种的植食性昆虫丰富度显著降低,但中性节肢动物丰富度却明显增加.高抗和中抗的节肢动物群落中位物种和顶位物种较之对照有所增多.转基因741杨节肢动物群落的害虫功能团,其优势状况,与对照相比有所改变:天敌优势度高于对照,中性节肢动物丰富度增加,并在天敌-害虫的营养链中起着重要的调控作用.鳞翅目害虫的空间生态位宽度最小,其它各功能类群的生态位宽度较大;捕食性和寄生性天敌与鳞翅目害虫的生态位重叠均较小,而与腐生和游逛种类的生态位重叠较大;各类害虫之间、捕食性天敌与寄生性天敌之间亦存在激烈竞争.转基因741杨对寄生性天敌和捕食性天敌在利用时间资源上有正作用.各种功能类群的时-空二维生态位宽度和生态位重叠均不如单维生态位宽度和生态位重叠值大,但抗性株系天敌类群对环境的适应性优于对照. 相似文献
16.
Niche partitioning and niche filtering jointly mediate the coexistence of three closely related spider species (Araneae,Philodromidae)
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1. Several mechanisms can mediate the coexistence of species, such as the neutral dynamic, niche filtering and niche partitioning. The present study investigated which of these mechanisms mediate the coexistence of closely related spider species at the scale of one locality. 2. The coexistence of three spider species of the genus Philodromus (Philodromidae) (Philodromus albidus, Philodromus aureolus and Philodromus cespitum) was studied. The study area comprised three habitat types, including a deciduous forest, a scrub and a plum tree stand. The spatial niche properties of the Philodromus species were explored by comparing their micro/macrohabitat preferences. The natural diet of these species was analysed. Laboratory experiments involving prey acceptance were conducted to investigate the trophic niche properties. The species' phenologies were studied to compare their temporal niches. 3. The philodromids had differentiated their trophic and habitat niches. The coexistence mechanisms were therefore assessed by studying the relationships between niche overlaps and the pairwise product of relative abundances. A negative relationship was observed between functional niche overlaps and the product of relative abundances, whereas a positive relationship was observed between spatial niche overlaps and the product of relative abundances. 4. The present results suggest that different mechanisms influence different niche dimensions. Niche partitioning influenced functional niches, whereas niche filtering influenced spatial niches. The results also suggest that the filtering process in one dimension was facilitated by niche differentiation in another dimension. 相似文献
17.
上海市地面藓类植物生态位研究 总被引:8,自引:1,他引:7
在上海市市区和西部郊区主要公园,以及吴泾化工厂和吴淞化工厂,共设立22个样点,调查发现共有7种地面藓类植物.根据Levins公式计算了7种藓类植物的生态位宽度.结果表明,藓类植物种数与生态位宽度符合:N=0.344×e-0.0377B,R=0.9684.大部分地面藓类植物生态位宽度很窄,68%种类生态位宽度小于0.1,因而在苔藓植物保护中应特别注意对小生境的保护.运用王刚的生态位重叠公式计测了其中重要值大于0.1的39种主要藓类植物的生态位重叠值,应用主坐标排序法和最小生成树法对它们进行分类.结果表明,这39种藓类植物可被分成5个生态类群,与生境有一定关系. 相似文献
18.
水、盐梯度下黄河三角洲湿地植物种的生态位 总被引:10,自引:0,他引:10
利用排序等方法将黄河三角洲湿地19个植物种在水深和土壤盐分梯度下依次排列,并分别划分为低、中、高水深(或土壤盐分)3个生态种组,分析了水、盐梯度下植物种的生态位宽度和生态位重叠.结果表明:水深梯度下,芦苇、盐地碱蓬等中水深生态种组植物种生态位宽度较大,香蒲、穗状狐尾藻等高水深生态种组植物种生态位宽度最小;土壤盐分梯度下,盐地碱蓬、柽柳等高土壤盐分生态种组植物种生态位宽度较大,而中、低土壤盐分生态种组的植物种生态位宽度均较小.水深和土壤盐分梯度下的生态位重叠分别沿着植物种在两种梯度上的排序而规律变化,通常同一生态种组内部植物种的生态位重叠较大,不同生态种组植物种的生态位重叠较小.黄河三角洲湿地植物种在水深、土壤盐分梯度下的生态位分化现象,可能有助于阐释湿地植物共存及带状分布的形成机制. 相似文献
19.
古田山青冈林优势种群生态位特征 总被引:20,自引:2,他引:18
利用样方法进行野外调查,每个样地大小20 m×20 m。采用生态位宽度、生态位相似比例和生态位重叠值公式统计分析了古田山自然保护区青冈林优势种群生态位特征。结果表明,古田山青冈林中青冈、马银花、木荷、甜槠、麂角杜鹃等具有较大的生态位宽度,其Bi、Ba分别为0.7974、0.6435、0.6272、0.5908、0.5783和0.7770、0.4012、0.4745、0.4171、0.4303;而光叶石楠和栲树的生态位宽度较小,Bi、Ba仅为0.3966、0.2716和0.1441、0.0825。生态位宽度大的种群间生态位相似比例较高,如青冈与马银花、麂角杜鹃的生态位相似比分别为0.6134、0.6056;反之则低,如光叶石楠和栲树生态位相似比为0.1039。生态位重叠与生态位宽度有一定的联系,高生态位宽度种群间的生态位重叠通常较大,反之则低。 相似文献
20.
Comparing macroecological patterns across continents: evolution of climatic niche breadth in varanid lizards
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Macroecological analyses often test hypotheses at the global scale, or among more closely related species in a single region (e.g. continent). Here, we test several hypotheses about climatic niche widths among relatively closely related species that occur across multiple continents, and compare patterns within and across continents to see if they differ. We focus on the lizard genus Varanus (monitor lizards), which occurs in diverse environments in Africa, Asia, and Australia. We address three main questions. 1) How do climatic niche breadths of species on a given niche axis change based on the position of species along that niche axis? (E.g. are species that occur in more extreme environments more narrowly specialized for those conditions?) 2) Are there trade‐offs in niche breadths on temperature and precipitation axes among species, or are niche widths on different axes positively related? 3) Is variation in niche breadths among species explained primarily by within‐locality seasonal variation, or by differences in climatic conditions among localities across the species range? We generate a new time‐calibrated phylogeny for Varanus and test these hypotheses within and between continents using climatic data and phylogenetic methods. Our results show that patterns on each continent often parallel each other and global patterns. However, in many other cases, the strength of relationships can change dramatically among closely related species on different continents. Overall, we found that: 1) species in warmer environments have narrower temperature niche breadths, but there is no relationship between precipitation niche breadth and niche position; 2) temperature and precipitation niche breadths tend to be positively related among species, rather than showing trade‐offs; and 3) within‐locality seasonal variation explains most variation in climatic niche breadths. Some of these results are concordant with previous studies (in amphibians and North American lizards), and might represent general macroecological patterns. 相似文献