Fragmentation and the Role of Seed Banks in Promoting Persistence in Isolated Populations of Collinsia verna

摘要: Plant species that inhabit environments characterized by environmental stochasticity and/or catastrophe have evolved two common bet-hedging strategies: one based on seed dispersal attributes and dormancy attributes, which lead to the formation of a soil bank. The conditions select for evolution spatial versus temporal will depend both magnitude variance array suitable habitat patches. In normally are connected as metapopulation, repeated local extinction occurs, recolonization available patches is accomplished dispersal. metapopulation structure, individuals distributed among series subpopulations another number in each subpopulation fluctuates according demogrpahic conditions, can fluctuate largely independently. These fluctuations numbers may periodically extirpate subpopulation, but persistence such enhanced because dispersing from other recolonize an extirpated area. Thus structure function enhances regional spatially temporally variable (Hanski Gilpin 1991). Spatiotemporal variability size probability favors high rates (Gadgil 1971, Cohen Levin 1991, den Boer 1987, McPeek Holt 1992). High enhance entire increasing rate extinct 1992, Ebenhard Verboom Lankester Hanski However, if distance exceeds capacity organism successful low, be favored.