Zur Diasporenausbreitung von Cymbalaria muralis (Scrophulariaceae)
Dispersal in Cymbalaria muralis can be interpreted as a two-stage process first of which is the well-known blastochorous mechanism leading to diaspore deposition in the vicinity of the parent plant depending on pedicel growth, availability and number of safe sites and competence between capsules, seeds and seedlings etc. The resulting small number of safe-site dispersed diaspores and the limited distances from the parent plants compensates thereby for the great seed losses of capsules that failed to reach safe sites. But observations in the field indicate that such diaspores are not only subject to highly incidental and unusual dispersal events. A great variety of factors like the asynchrony of dehiscence, hygroscopic movements of capsule teeth, the formation of seed clusters, different patterns of seed germination due to seed size and surface structure including germination of the basifix seed, the use of seeds and capsules as diaspores etc. provide complex functional interactions enabling the species to take advantage of a broad range of biotic and abiotic dispersal vectors influencing dispersal patterns in space and time. With partitioning the reproductive effort between those diaspores that failed to reach a safe site (enabling a potential long-range seed dispersal to colonize new habitats) and those that replace existing individuals allowing only a limited population growth Cymbalaria muralis maximizes dispersal economy by combining the benefits from both strategies.
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