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1.
植物地上竞争与地下竞争研究进展   总被引:2,自引:0,他引:2  
王平  王天慧  周道玮  张红香 《生态学报》2007,27(8):3489-3499
植物地上光竞争和地下水分与营养的竞争过程十分复杂,并且与竞争机制密切相关。从地上和地下竞争理论、两种竞争过程的相互作用机制以及分离地上和地下竞争的研究方法和表达指标等几个方面综述和分析目前的研究状况,以期为国内研究者在本领域进一步展开实验提供理论依据和实验设计参考。总结了与地上、地下相对竞争强度有关的优化分配理论,地上、地下竞争随生产力梯度的变化,资源异质性对地上、地下竞争机制的影响。介绍了地上竞争和地下竞争相互作用类型以及目前提出的两种作用机制。对常用的3种分离地上、地下竞争的方法:盆分隔、间植分隔和目标植分隔法以及表达竞争强度和竞争重要性的指标和公式进行了归纳。提出未来的研究内容,认为在开展此类研究时,应考虑到实验植物的生理学特性、发育状况、立地生产力跨度范围以及竞争持续时间等方面因素,并认为发展地下竞争研究、深入探讨根系间相互作用的影响因子和过程是当前的研究热点。  相似文献   

2.
Competition is ubiquitous in plant communities with various effects on plant fitness and community structure. A long-standing debate about different approaches to explain competition is the controversy between David Tilman and Philip Grime. Grime stated that the importance of competition relative to the impact of the environment increases along a productivity gradient, while Tilman argued that the intensity of competition is independent of productivity. To revisit this controversy, we assumed that the effects of plant–plant interactions are additive and applied the new competition indices by Díaz-Sierra et al. (2017) in a field experiment along a productivity gradient in S-Germany, using the rare arable plant Arnoseris minima as a study species. The ‘target technique' was applied, to separate the effects of root and shoot competition. The study plants were exposed to five competition treatments with three replicates in 18 sites, respectively. We investigated the expectation that root competition is more intense in unproductive sites than shoot competition. Additionally, we predicted survival to be less affected by competition than growth-related plant parameters. Using the biomass of individuals without competition as a proxy for site productivity there was a positive relationship with competition importance but no relationship with competition intensity when plants experienced full competition. Survival of the target plants was unaffected by competition. Root competition was the main mechanism determining the performance of the target plants, whereas the effect of shoot competition was relatively low albeit increasing with productivity. We conclude that when considering plant–plant interactions additive both Grime's and Tilman's theories can be supported.  相似文献   

3.
黄土高原马栏林区辽东栎林种内、种间竞争研究   总被引:8,自引:0,他引:8  
利用Hegyi的单木竞争指数模型对黄土高原马栏林区辽东栎(Quercus liaotungensis)的种内和种间竞争强度进行了定量分析.结果显示:(1)辽东栎种内竞争强度与种间竞争强度的总和大致相等,其种内及种间竞争强度均随对象木胸径的增大而逐渐减小,其关系服从幂函数规律,竞争主要发生在胸径小于15 cm的幼树阶段.(2)各组成树种对辽东栎影响程度(竞争指数)的大小顺序为:辽东栎>油松(Pinus tabulaeformis)>白桦(Betulaplatyphylla)>山杨(Populus davidiana)>杜梨(Pyrus betulaefolia)>湖北山楂(Crataegus hupehensis)>茶条槭(Acer ginnala)>陕西鹅耳枥(Carpinus shensiensis)>葛萝槭(A.grosseri).(3)油松是该地区的次优势种,对辽东栎有较大的竞争压力,在群落发展中可能会形成以油松占优势的混交林.(4)辽东栎胸径小于15 cm时,种内种间竞争是导致大量个体死亡的主要原因;胸径超过15 cm时,人为砍伐可能是个体死亡的主要原因.研究结果认为马栏林区混交林油松的密度不宜过大,尤其是在与未成熟辽东栎种群混交时密度应合理,应对该林区的混交林进行人工抚育,及时择伐密度过大的油松,而在辽东栎胸径达到15 cm之前择伐长势较差的植株,以促使森林群落尽快趋于稳定.  相似文献   

4.
山西稀有濒危植物脱皮榆种内和种间竞争   总被引:2,自引:0,他引:2  
通过对山西太岳山一块100 m×100 m样地中128株脱皮榆对象木及1093株竞争木的调查,运用Hegyi的单木竞争指数计算分析了脱皮榆的种内和种间竞争强度。结果表明:(1)脱皮榆种群所受到的竞争强度随着对象木胸径的增大而逐渐减小;(2)调查样地内尽管其他物种种类较多,但数量较少,与脱皮榆种间竞争相对较弱,脱皮榆种内与种间竞争关系的顺序为:脱皮榆-脱皮榆>千金榆-脱皮榆>五角枫-脱皮榆>茶条槭-脱皮榆>其他树种-脱皮榆;(3)竞争强度和对象木胸径的关系服从幂函数关系,当脱皮榆胸径在25 cm以上时,竞争强度变化不大,所得的预测模型能很好地预测脱皮榆种内种间竞争强度。  相似文献   

5.
长苞铁杉天然林群落种内及种间竞争关系研究   总被引:15,自引:3,他引:12  
通过各种竞争指数的比较筛选,得到较能客观反映长苞铁杉种内、种间竞争关系的竞争指数,定量地分析了长苞铁杉种内和种间竞争强度。结果表明:长苞铁杉种内竞争随胸径的增大而逐渐减少;种间与种内竞争关系顺序为:长苞铁杉-长苞铁杉>猴头杜鹃-长苞铁杉>青冈栎-长苞铁杉>其它树种-长苞铁杉。竞争强度与对象木的胸高直径服从双曲线回归关系,利用模型预测了长苞铁杉种内、种间的竞争强度。  相似文献   

6.
天然东北红豆杉(Taxus cuspidata)种内和种间竞争   总被引:20,自引:4,他引:16  
竞争是植物种内和种间关系的主要形式之一。通过对黑龙江穆棱东北红豆杉自然保护区的95株东北红豆杉对象木及980株竞争木的调查,运用Hegyi的单木竞争指数计算分析了东北红豆杉的种内和种间竞争强度。东北红豆杉的种内竞争强度不大,占总竞争的4%。竞争压力更多的来自于种间竞争,占总竞争的96%。与东北红豆杉竞争激烈的树种主要是冷杉、紫椴、色木槭和红松等地带性植被的优势种。随着东北红豆杉胸径的增大,所受到的竞争压力逐渐减小,胸径在20cm以前所受到的竞争压力最大,竞争强度与对象木胸径符合幂函数(CI=AD^-B)关系。  相似文献   

7.
天柱山黄山松种内与种间竞争的研究   总被引:3,自引:0,他引:3  
采用改进的竞争指数模型研究安徽天柱山黄山松的种内和种间竞争强度。结果发现:(1)随对象木胸径的增大,黄山松种群因自然稀疏过程中密度调节作用,植株距离增加,种内竞争强度降低;(2)黄山松群落内其它物种虽然较多,但个体普遍较小,结果种间竞争相对较弱,种内与种间竞争关系顺序为:黄山松—黄山松>杉木—黄山松>枹栎—黄山松>其它树种—黄山松;(3)竞争强度和对象木胸径的关系服从幂函数关系(CI=AD-B),当黄山松胸径达到20cm以上时,竞争强度变化不大,所得的预测模型能很好地预测黄山松种内和种间的竞争强度;(4)改进的竞争指数模型能很好地度量黄山松的种内和种间竞争强度,改进的确定邻体范围的方法能有效地确定黄山松的竞争范围。  相似文献   

8.
Larval competition between contest and scramble strategists was investigated using the two bruchid species, C. analis (contest species) and C. phaseoli (scramble species) with two different sized mung beans (large and small beans). In both sized beans, the adult emergences of each species dependen on total density of the initial larval densities of the two species and the ratio of the two densities. The emergence of one species was suppressed by the existence of the other species when the initial larval density per bean of the former species was less than that of the latter one. There were many cases in which both C. analis and C. phaseoli emerged from one bean in large beans, but such cases were quite rare in small beans. C. analis performed interference behavior only at late larval stages, whereas C. phaseoli was superior in exploitative competition all through their larval stages. These, combined with the niche segregation inside a bean, are throught to be the major factors of observed density- and frequency-dependent competition results. Based on the above experimental results, long-term competition results between the contest and scramble species were predicted.  相似文献   

9.
濒危植物宝华玉兰种内与种间竞争   总被引:7,自引:2,他引:5       下载免费PDF全文
利用Hegyi单木竞争指数模型对江苏镇江宝华山国家森林公园特有濒危植物宝华玉兰种内、种间竞争强度进行定量分析。结果表明:宝华玉兰竞争压力主要来自种间,占总竞争的90.7%。宝华玉兰种内竞争、种间竞争强度大小顺序为:紫楠>野核桃>建始槭>宝华玉兰种内>毛竹>化香>枫香>皂荚>朴树。整个林分竞争木对对象木的竞争强度与对象木的胸径大小近似服从幂函数关系,而伴生树种竞争木对对象木的竞争强度与对象木的胸径大小近似服从对数函数关系。种间竞争强度和对象木的胸径大小呈显著负相关。利用模型预测,当宝华玉兰的胸径达到30cm后,竞争强度几乎没有变化。研究认为,将无性系分株换算为一株与其胸高断面积之和相等的个体更为合理。  相似文献   

10.
蒙古栎(Quercus mongolica Fischer ex Ledebour)林是东北地区常见的典型森林类型之一。以黑龙江中央站黑嘴松鸡国家级自然保护区面积为1 hm2的蒙古栎林固定样地为研究对象,采用固定样圆法确定了竞争范围,并利用Hegyi竞争指数分析了蒙古栎林的种内和种间竞争状态。研究结果表明:蒙古栎的种内和种间竞争强度分别占总竞争强度的28.08%和71.92%,说明了蒙古栎的种内竞争强度小,竞争压力主要来自于种间。白桦(Betula platyphylla Suk.)、黑桦(Betula dahurica Pall.)、兴安落叶松(Larix gmelinii(Ruprecht)Kuzeneva)数量较多,个体高大,对蒙古栎的竞争压力较大。蒙古栎种内和种间竞争强度的顺序为:白桦 > 蒙古栎 > 黑桦 > 兴安落叶松 > 山杨(Populus davidiana Dode) > 紫椴(Tilia amurensis Rupr.) > 大黄柳(Salix raddeana Laksch.)。蒙古栎的胸径与整个林分、伴生树种以及蒙古栎种内的竞争强度成幂函数关系,随着对象木胸径增大,3种竞争强度均减小。当蒙古栎胸径小于20 cm时,竞争强度较大;当胸径大于20 cm时,蒙古栎所受的竞争压力较小,并趋于稳定,通过所得的模型可以很好地预测出蒙古栎种内和种间的竞争强度。  相似文献   

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