生物多样性 ›› 2001, Vol. 09 ›› Issue (1): 25-37.  DOI: 10.17520/biods.2001004

• 论文 • 上一篇    下一篇

动物与植物种子更新的关系Ⅱ.动物对种子的捕食、扩散、贮藏及与幼苗建成的关系

李宏俊,张知彬   

  1. (中国科学院动物研究所,北京 100080)
  • 收稿日期:2000-07-20 修回日期:2001-02-20 出版日期:2001-02-20 发布日期:2001-02-20
  • 通讯作者: 张知彬

Relationship between animals and plant regeneration by seed Ⅱ. Seed predation, dispersal and burial by animals and relationship between animals and seedling establishment

LI Hong-Jun, ZHANG Zhi-Bin   

  1. Institute of Zoology,Chinese Academy of Sciences,Beijing 100080
  • Received:2000-07-20 Revised:2001-02-20 Online:2001-02-20 Published:2001-02-20
  • Contact: ZHANG Zhi-Bin

摘要: 植物的繁殖体总是面临来自各类生物 (如昆虫、脊椎动物、真菌) 的捕食风险。因动物捕食引起的种子死亡率影响植物的适合度、种群动态、群落结构和物种多样性的保持。种子被捕食的时间和强度成为植物生活史中发芽速度、地下种子库等特征的主要选择压力,而种子大小、生境类型等因素也影响动物对植物种子的捕食。捕食者饱和现象被认为是植物和种子捕食者之间的高度协同进化作用的结果,是限制动物破坏种子、提高被扩散种子存活率的一种选择压力。大部分群落中的大多数植物种子被动物扩散。种子扩散影响种子密度、种子被捕食率、病原体攻击率、种子与母树的距离、种子到达的生境类型以及建成的植株将与何种植物竞争,从而影响种子和幼苗的存活,最终影响母树及后代植物的适合度。种子被动物扩散后的分布一般遵循负指数分布曲线,大多数种子并没有扩散到离母树很远的地方。捕食风险、生境类型、植被盖度均影响动物对种子的扩散。植物结实的季节和果实损耗的过程也体现了其对扩散机会的适应。许多动物有贮藏植物种子的行为。动物贮藏植物繁殖体的行为,一方面调节食物的时空分布,提高了贮食动物在食物缺乏期的生存概率;另一方面也为种子萌发提供了适宜条件,促进了植物的扩散。于是,植物与贮食动物形成了一种协同进化关系,这种关系可能是自然界互惠关系(mutualism)的一种。影响幼苗存活和建成的因子包括种子贮藏点的微生境、湿度、坡向、坡度、林冠盖度等。许多果食性动物吃掉果肉后,再将完好的种子反刍或排泄出来。种子经动物消化道处理后,发芽率常有所提高。

AbstractThe propagules of plants are exposed to high risk of attack by natural predators, such as insects, vertebrates and fungi. Seed mortality due to predation by animals may affect plant fitness, population dynamics, community structure and maintenance of species diversity. The time and intensity of seed predation can be a major selective force in the evolution of life history traits in plants, such as germination rates and production of a soil seed bank. Seed size and the type and patchiness of habitat affect seed predation by animals. Predator satiation is a highly coevolved behavior interaction of plant with seed predator, and has been proposed as a selective factor limiting the destructive abilities of animals and promoting the survival of dispersed seeds. Several hypotheses have been proposed to explain the spatial relationship between plant regeneration and seed dispersal. Seed dispersal can be regarded as a key process in the survival and distribution of plant species. Seeds are dispersed through a variety of ways. Seed dispersal affects the fitness of parent and offspring plants through its effects on seed density, the distance seeds are moved from the parent tree, and the habitat where seeds arrive. Difference in dispersal may influence early seed and seedling survival by affecting incidence of predation or attack by pathogens, the habitat into which seeds are dispersed, and the types of plants with which the developing plant will compete. Seed distribution generally exhibits a negative exponential function, most seeds are not disperse very far from the parent plant. Predation risk, habitat type and vegetation cover are factors which affect animal dispersal of seeds. The fruiting season and fruit loss process of plants reflects adaptation to dispersal opportunities. A large number of animals hoard plant seeds. This behavior not only adjusts spatio temporal distribution of food and enhances animal survival in times of food shortage, but also promotes plant dispersal. So, there is coevolutionary relationship between plant and animal which cache or hoard seeds. Seed dispersal by animals is one of the most important of mutualistic systems. Many factors affect the survival and establishment of seedling, such as microhabitat, humidity, slope, gradient, cover of the cache. Frugivorous animals usually consume the pulp and regurgitate or defecate the seeds intact. Seed treatment within the guts of seed dispersers is contributive to seed emergence.