Competition and coexistence in plant community in relation to strategy of resource us

植物群落竞争与共存与资源利用策略

• 批准号: 08454248
• 负责人: HIROSE Tadaki
• 金额: $ 5.5万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08454248/
• 关键词: Competition; Coexistence; resoure; acquisition; Environmental variability; Female-bias; Sexual allocation; Sink-limited growth; 物質分配; 光合成; 光; 窒素

A plant community consists of individuals and species which are different in size from each other. We studied how those individuals and species acquire and use limiting resources in the community to elucidate the mechanism of competition and coexistence among species and individuals. In the Miscanthus sinensis grassland meadow at Kawatabi, Miscanthus dominated upper layrs of the canopy, while many smaller subordinate species such as Potentila and Lysimachia coexisted in the understory. Although those subordinate understory species absorbed much smaller amounts of PPFD than dominant Miscanthus, they have larger leaf area relative to aboveground biomass and consequently the PPFD absorbed per unit aboveground biomass was closer to that of Miscanthus. This suggests that a similar efficiency of light acquisition per unit investment of aboveground biomass is a necessary condition for species coexistence in a plant community. We studied a natural stand of Xanthium canadense at the shore of La … More ke Kamahusa as a competition system. Tall individuals were in the upper layr and absorbed large amounts of available PPFD.Difference in the leaf area ratio between individuals in upper and lower layrs was limited and consequently the efficiency of light acquisition of the individuals in the upper layr was still larger than that in the lower layr individuals. This made a strong contrast against the coexistence system given above. From a comparison between stands different in the growth stage, it was shown that plant height and light climate controlled leaf area development of individuals. We further studied photosynthetic characteristics of leaves in a canopy established experimentally at two nitrogen availabilities. Leaf nitrogen concentration tended to be higher in leaves of plants in lower layrs when compared at a common light climate. However, nitrogen use in leaf photosynthesis depended solely on the light climate of the leaf.We developed optimal-allocation models to investigate bet-hedging on ovule production as an evolutionary strategy in environments where either pollinator availability or resource availability is unpredictable. We showed that large variability in pollinator or resource availability does not always select for an increase in the number of ovules produced by the plant. Rather, the plant decreases its I ovule number in habitats where pollinator or resource availability is more variable. To explain female-biased sexual allocation in cosexual plants, we developed a game theoretic model incorporating a source-sink relationship of flower/fruit growth. In this model, flower/fruit growth rate is either limited by its sink strength (the product of its potential relative growth rate and absolute size) or by the source strength (instantaneous amount of resources available) of the plant. We showed that female-biased sexual allocation is evolutionarily stable if fruit growth is sink-limited at least in the early stage of its growth. Less

植物群落由个体和物种组成，它们的大小彼此不同。通过研究这些个体和物种如何获取和利用群落中的有限资源，阐明物种和个体之间的竞争与共存机制。在川比芒草地草甸，芒占主导地位的上层的冠层，而许多较小的从属物种，如Potentila和过路黄共存于林下。虽然这些次级林下物种吸收的PPFD量比优势芒草少得多，但它们相对于地上生物量具有较大的叶面积，因此单位地上生物量吸收的PPFD更接近芒草。这表明，类似的光获取效率每单位投资的地上生物量是物种共存的植物群落中的必要条件。本文研究了位于La海岸的加拿大苍耳（Xanthium canadense）天然林 ...更多信息 作为一个竞争系统。高株位于上层，吸收大量有效PPFD，上下层个体间叶面积比差异有限，上层个体的光获取效率仍大于下层个体。这与上面给出的共存系统形成了强烈的对比。不同生长阶段林分间的比较表明，株高和光气候控制着个体叶面积的发育。在此基础上，进一步研究了两种氮素有效性条件下冠层叶片的光合特性。在一般光照条件下，低层植物叶片氮浓度有较高的趋势。然而，在叶片光合作用中的氮利用完全取决于光气候的leaf.We开发的最优分配模型，调查赌注对冲胚珠生产的进化策略，在环境中，无论是传粉者的可用性或资源的可用性是不可预测的。我们发现，传粉者或资源可用性的大变异并不总是选择增加植物产生的胚珠数量。相反，在传粉者或资源可用性更易变的栖息地，植物减少了其胚珠数量。为了解释雌性偏向的性分配在雌雄同体的植物，我们开发了一个博弈论模型，将源库关系的花/果实生长。在这个模型中，花/果实的生长速率要么受到其库强度（其潜在的相对生长速率和绝对大小的乘积）的限制，要么受到植物的源强度（瞬时可用资源量）的限制。我们发现，女性偏向性分配是进化稳定的，如果水果的生长是水槽限制至少在其生长的早期阶段。少

项目成果

Sakai S,Sakai A.: "Why is there variaion in mean seed size among plants within single populations? Test of the fertilization efficiency hypothesis." American Jaurnal of Botany. 83. 1454-1457 (1996)

Sakai S，Sakai A.：“为什么单个种群内的植物平均种子大小存在差异？受精效率假设的检验。”

Sakai S,Sakai A,Ishii SH.: "Patterns of wing size variation in seeds of the lily Cardiocrinum cordatum (Liliaceae)." American Journal of Botany. 84. 1275-1278 (1997)

Sakai S，Sakai A，Ishii SH.：“百合 Cardiocrinum cordatum（百合科）种子翅膀大小变化的模式。”

Sakai S.: "Does the trade-off between growth and reproduction select for female-biased sexual allocation in cosexual plants?" Evolutionary Ecology. (in press).

Sakai S.：“生长和繁殖之间的权衡是否会选择同性植物中雌性偏向的性别分配？”

Hikosaka K: "Effects of leaf age,nitrogen nutrition and photon flux density on the organization of the photosynthetic apparatus in leaves of a vine (Ipomoea tricolor Cav.)grown horizontally to avoid mutual shading of leaves" Planta. 198. 144-150 (1996)

Hikosaka K：“叶龄、氮营养和光子通量密度对水平生长的藤本植物（Ipomoea tricolor Cav.）叶子光合机构组织的影响，以避免叶子相互遮蔽”Planta。

Sakai A, Sakai S, Akiyama F: "Do sprouting tree species on erosion-prone sites carry large reserves of resources?" Annals of Botany. 79. 625-630 (1997)

Sakai A、Sakai S、Akiyama F：“易受侵蚀地点发芽的树种是否蕴藏着大量资源？”