Carbon assimilation and habitat segregation in resurrection plants: a comparison between desiccation- and non-desiccation-tolerant species of Neotropical Velloziaceae (Pandanales)

Desiccation tolerance is the ability that some organisms show to equilibrate their water content with that of dry air and recover when water supplies are re-established. This is a widespread although rare strategy in angiosperms, and most desiccation-tolerant (DT) species are restricted to tropical rock outcrops. Such restricted ecological range is attributed to weak competitive potential caused by low productivity, due to the temporal limitation in carbon assimilation that occurs when plants desiccate. However, few studies addressing this question in angiosperms have been conducted. We investigate 20 species of Velloziaceae of campos rupestres that differ in their desiccation tolerance. Campos rupestres is an ecoregion characterized by particular vegetation growing on rocky substrates that occurs along mountains in central/south-eastern Brazil, above 900 m a.s.l. It is considered a Neotropical hotspot and the main centre of diversity for DT vascular plants and the Velloziaceae. Here, w...

干燥耐受性是某些生物具备的一种能力，即能使其水分含量与干燥空气的水分含量达到平衡，并在水分供应恢复时恢复生机。这是被子植物中虽广泛存在但较为罕见的策略，大多数干燥耐受（DT）物种局限于热带岩石露头区域。这种受限的生态范围被认为是低生产力导致竞争潜力较弱所致，而低生产力源于植物干燥时碳同化作用的时间限制。然而，针对被子植物中这一问题的研究却寥寥无几。我们研究了岩石草地（campos rupestres）中的20种翡若翠科（Velloziaceae）植物，这些植物的干燥耐受性存在差异。岩石草地（campos rupestres）是一种生态区，其特征是特定植被生长在岩石基质上，分布于巴西中东部/东南部山区海拔900米以上的区域。它被认为是新热带区的生物多样性热点，也是干燥耐受（DT）维管植物和翡若翠科植物的主要多样性中心。在此，我...