Miller T E
W.K. Kellogg Biological Station, Michigan State University, 49060, Hickory Corners, MI, USA.
Oecologia. 1987 May;72(2):272-278. doi: 10.1007/BF00379278.
The time at which plants emerge from the soil is shown to be correlated with both survival and growth in each of four years in a plant community emerging after yearly plowing. For all seven species investigated, earlier emerging individuals generally had both a higher biomass and probability of survival. There were differences among species in the effect of emergence time on biomass, with the growth of upright, annual species being more suppressed by later emergence than the growth of other species. No significant differences were found among species in the effects of emergence time on survival. It was expected that differences among species in the effect of emergence time on fitness might lead to a correlation between the patterns of emergence time and species characteristics such as growth form or lifespan. Mean emergence times did vary significantly among both the seven species and the four years of the study. However, there was no correlation between emergence time and species lifespan, growth form, abundance, or competitive ability. The lack of a correlation between the selection pressure on species and their emergence time could be due low heritability, insufficient time for selection and evolution, and/or selection on correlated characters.
在每年翻耕后出现的植物群落中，植物从土壤中出土的时间被证明与四年中每一年的存活率和生长情况都相关。对于所研究的所有七个物种而言，较早出土的个体通常具有更高的生物量和存活率。出土时间对生物量的影响在物种间存在差异，直立一年生物种的生长比其他物种的生长受到较晚出土的更大抑制。在出土时间对存活率的影响方面，未发现物种间存在显著差异。预计出土时间对适合度的影响在物种间的差异可能导致出土时间模式与物种特征（如生长形式或寿命）之间存在相关性。在研究的七个物种以及四年间，平均出土时间确实存在显著差异。然而，出土时间与物种寿命、生长形式、丰度或竞争能力之间没有相关性。物种所受选择压力与其出土时间之间缺乏相关性，可能是由于低遗传力、选择和进化的时间不足，以及/或者对相关性状的选择。
