Abstract:
Macroalgal populations often consist of free-living haploid (gametophyte) and diploid (sporophyte) stages. Various ecological studies have been conducted to examine the demographic diversity of haploid-diploid populations with regard to the dominant stage. Here, I relaxed the assumption of classical research that the life history parameters of haploids and diploids are identical and developed a generalized haploid-diploid model that explicitly accounts for population density dependence and asexual reproduction. Analysis of this model yielded an exact solution for the abundance ratio of haploids to diploids in a population in which the ratio is determined by the balance of four demographic forces: sexual reproduction by haploids, sexual reproduction by diploids, asexual reproduction by haploids, and asexual reproduction by diploids. Furthermore, the persistence of a haploid-diploid population and its total biomass are shown to be determined by the basic reproductive number (R0), which is shown to be a function of these four demographic forces. When R0 is greater than one, the haploid-diploid population stably persists, and the ploidy ratio obtained by the analytical solution is realized.
摘要:
大型藻类种群通常由自由生活的单倍体(配子体)和二倍体(孢子体)阶段组成。已经进行了各种生态学研究,以检查单倍体-二倍体种群在优势阶段的人口统计学多样性。这里,我放宽了经典研究的假设,即单倍体和二倍体的生活史参数是相同的,并开发了一个广义的单倍体-二倍体模型,该模型明确解释了种群密度依赖性和无性繁殖。对该模型的分析为种群中单倍体与二倍体的丰度比提供了精确的解决方案,其中该比率由四种人口力量的平衡决定:单倍体的有性生殖,二倍体的有性生殖,单倍体无性繁殖,和二倍体的无性繁殖。此外,单倍体-二倍体种群的持久性及其总生物量由基本繁殖数(R0)决定,这被证明是这四种人口力量的函数。当R0大于1时,单倍体-二倍体种群稳定存在,并且实现了由分析溶液获得的倍性比。