Université Libre de Bruxelles, Laboratoire d'Ecologie végétale et Biogéochimie, Bruxelles, Belgium.
Plant Biol (Stuttg). 2011 Jan;13 Suppl 1:125-35. doi: 10.1111/j.1438-8677.2010.00387.x. Epub 2010 Aug 17.
We examined recruitment, survival, life cycle and fecundity of two metallicolous (M, on metalliferous calamine soils) and two non-metallicolous (NM, on normal soils) populations of Thlaspi caerulescens in Belgium and Luxemburg. In each population, permanent plots were monitored over two reproductive seasons. In M populations, plots were located in two contrasting environments (grass versus grove) in order to test the influence of vegetation cover on life strategy. Our results show that the monocarpic life cycle is dominant in all populations of T. caerulescens. However the length of the pre-reproductive period varies from several months (winter annuals) to 1 year or more (perennials), and is partly related to plant origin (M versus NM). Most plants growing in metalliferous environments were annuals, whereas NM plants were mostly perennials. These differences in life cycle were related to differences in survival during summer, which was better in NM than in M populations. Within each M population, different survival conditions and life cycles were observed according to vegetation cover. Plants growing in grass areas were mostly annuals and had a low survival rate in summer whereas grove plants were mostly perennials and survived better in summer. Our results suggest the selection of stress avoiders (shortening of life cycle) in M populations of T. caerulescens but only for individuals growing in grass areas. Summer survival seems to play a key role in selection of life strategy in T. caerulescens.
我们研究了比利时和卢森堡的两种金属（M，在含金属菱锌矿土壤上）和两种非金属（NM，在正常土壤上）的蓝蓟的种群的繁殖、生存、生命周期和繁殖力。在每个种群中，两个繁殖季节都对永久性样地进行了监测。在 M 种群中，样地位于两种不同的环境（草地与树林）中，以检验植被覆盖对生活策略的影响。我们的研究结果表明，单年生活史在蓝蓟的所有种群中占主导地位。然而，预繁殖期的长度从几个月（冬性一年生植物）到 1 年或更长（多年生植物）不等，部分与植物起源（M 与 NM）有关。在金属环境中生长的大多数植物是一年生植物，而 NM 植物大多是多年生植物。这些生命周期的差异与夏季生存能力的差异有关，NM 种群的生存能力优于 M 种群。在每个 M 种群内，根据植被覆盖情况，观察到不同的生存条件和生命周期。生长在草地地区的植物大多是一年生植物，夏季生存率较低，而树林植物大多是多年生植物，夏季生存能力较好。我们的研究结果表明，在蓝蓟的 M 种群中选择了避压者（缩短生命周期），但仅针对生长在草地地区的个体。夏季生存似乎在蓝蓟生活策略的选择中起着关键作用。
