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A seed dispersal syndrome is a mutualistic plant-animal interaction.〔Herrera, C. M. & Pellmyr, O. (2002). ''Plant Animal Interactions: An Evolutionary Approach''. USA: Blackwell Science Ltd〕 Seed dispersal syndromes are morphological characters of seeds correlated to particular seed dispersal agents.〔Clobert, J., Le Galliard, J.F., Cote, J., Meylan, S. & Massot, M. (2009). Informed dispersal, heterogeneity in animal dispersal syndromes and the dynamics of spatially structured populations. Ecology Letters, 12, 197-209.〕〔Griz, L.M.S. & Machado, I.C.S. (2001). Fruiting phenology and seed dispersal syndromes in caatinga, a tropical dry forest in the northeast of Brazil. Journal of Tropical Ecology, 17, 303-321.〕〔Link, A. & Stevenson, P.R. (2004). Fruit dispersal syndromes in animal disseminated plants at Tinigua National Park, Colombia. Revista Chilena de Historia Natural, 77, 319-334.〕〔Tamboia, T., Cipollini, M.L. & Levey, D.J. (1996). An Evaluation of Vertebrates Seed Dispersal Syndromes in Four Species of Black Nightshade. Oecologia, 107(4), 522-532.〕 Dispersal is the event by which individuals move from the site of their parents to establish in a new area.〔Herrera, C. M. & Pellmyr, O. (2002).Plant Animal Interactions: An Evolutionary Approach. USA: Blackwell Science Ltd〕 A seed disperser is the vector by which a seed moves from its parent to the resting place where the individual will establish, for instance an animal. Similar to the term syndrome, a diaspore is a morphological functional unit of a seed for dispersal purposes.〔Booth, D. T. (1990). Plant diaspore functions. Journal of Seed Technology, 14(1), 61-73.〕 Characteristics for seed dispersal syndromes are commonly fruit colour, mass, and persistence.〔 These syndrome characteristics are often associated with the fruit that carries the seeds. Fruits are packages for seeds, composed of nutritious tissues to feed animals. However, fruit pulp is not commonly used as a seed dispersal syndrome because pulp nutritional value does not enhance seed dispersal success.〔 Animals interact with these fruits because they are a common food source for them. Although, not all seed dispersal syndromes have fruits because not all seeds are dispersed by animals. Suitable biological and environmental conditions of dispersal syndromes are needed for seed dispersal 〔 and invasion success 〔 such as temperature and moisture. Seed dispersal syndromes are parallel to pollination syndromes, which are defined as floral characteristics that attract organisms as pollinators.〔Fenster, C. B., Armbruster, W. S., Wilson, P., Dudash, M. R. & Thomson, J. D. (2004). Pollination Syndromes and Floral Specialization. Annual Reviews of Ecology, Evolution and Systematics, 35, 375-403.〕 They are considered parallels because they are both plant-animal interactions, which increase the reproductive success of a plant. However, seed dispersal syndromes are more common in gymnosperms, while pollination syndromes are found in angiosperms.〔 Seeds disperse to increase the reproductive success of the plant. The farther away a seed is from a parent, the better its chances of survival and germination. Therefore a plant should select certain traits to increase dispersal by a vector (i.e. bird) to increase the reproductive success of the plant. == Evolution == Seeds have evolved traits to reward animals to enhance their dispersal abilities.〔 Differing foraging behaviours of animals can lead to selection of dispersal traits and spatial variation 〔〔Castro, S., Ferrero, V., Loureiro, J., Espadaler, X., Silveira, P. & Navarro, L. (2010). Dispersal mechanisms of the narrow endemic Polygala vayredae: dispersal syndromes and spatio-temporal variations in ant dispersal assemblages. Plant Ecology, 207, 359-372.〕 such as increase in seed size for mammal dispersal, which can limit seed production.〔Fischer, K.E. & Chapman, C.A. (1993). Frugivores and Fruit Syndromes: Differences in Patterns at the Genus and Species Level. Oikos, 66(3), 472-482.〕 Seed production is limited by some seed syndromes because of their cost to the plant. Therefore, seed dispersal syndromes will evolve in a plant when the trait benefit outweighs the cost.〔 The seed dispersers themselves play an essential role in syndrome evolution.〔Butler, D.W., Green, R.J., Lamb, D., McDonald, W.J.F. & Forster, P.I. (2007). Biogeography of seed-dispersal syndromes, life-forms and seed sizes among woody rain-forest plants in Australia’s subtropics. Journal of Biogeography, 34, 1736-1750.〕 For example, birds put strong selection pressure on seeds for colour of fruits because of their enhanced vision. Illustrations of such colour evolution include green colour being produced because its photosynthesis abilities are less costly 〔Lomascolo, S.B., Speranza, P. & Kimball, R.T. (2008). Correlated evolution of fig size and color supports the dispersal syndromes hypothesis. Oecologia, 158, 783-796.〕 while red colour emerges as a byproduct for protection from arthropods 〔 For visible characteristic differences to develop between dispersers and non-dispersers a few conditions need to be met 1. Specialization must increase dispersal success whether morphological, physiological or behavioural 2. Energy investment for dispersal will be taken from energy investment of other traits 3. Dispersal traits will benefit the dispersers over non-dispersers. Phenotypic (visible characteristics) differences in non-dispersers and dispersers can be caused by external factors, kin competition, intraspecific competition and habitat quality.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Seed dispersal syndrome」の詳細全文を読む スポンサード リンク
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