Drought Impacts Survivorship and Reproductive Strategies of an Epiphyllous Leafy Liverwort in Central Amazonia
Drought Impacts Survivorship and Reproductive Strategies of an Epiphyllous Leafy Liverwort in Central Amazonia
复制标题
干旱影响亚马逊中部叶生叶类苔藓的生存和繁殖策略
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发表时间：
2015
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影响因子：
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通讯作者：
Cristian Sales Dambros
中科院分区：
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作者：
C. Zartman;J. A. Amaral;J. N. Figueiredo;Cristian Sales Dambros
了解不断变化的降水模式如何影响亚马逊植物的种群动态对于预测它们的长期生存是必要的。大多数陆生植物的特点是生命周期缓慢，难以评估这样的人口后果。由于需要在短暂的基质上生存，如叶表面，叶上（叶栖）的芽生植物具有陆地植物中最快的世代时间。考虑到这些优势，我们调查了在一年的叶附生bradula flaccida Gott的降水季节性的人口后果。（齿舌科）在亚马逊雨林中部。在一个1公顷大小的研究区域，154个附生菌落来自林下灌木Naucleopsis ulei（Warb.）鸭（桑科）的标记和菌落生长，灭绝，繁殖，以及性和无性表达率进行了测量，在9个人口普查。在旱季，由于落叶量增加（例如，被占据的斑块的损失）和持续叶片上的群体死亡率。无性表达也显着下降，在最干燥的月份，然而，性表达，孢子体密度测量，与季节性无关。逻辑回归概率也表明最佳孢子体表达的最小阈值菌落大小。较低的生存率和菌落生长在旱季沿着减少孢子体生产在较小的殖民地意味着，无论气候模型预测长期干旱的区域是准确的，人口的稳定性以及人口结构的亚马逊附生植物物种可能会受到损害。
Understanding how changing precipitation patterns impact the population dynamics of Amazonian plants is necessary for predicting their long‐term survival. Most terrestrial plants are characterized by life cycles intractably slow for evaluating such demographic consequences. Due to the demands of surviving on an ephemeral substrate such as a leaf surface, epiphyllous (leaf‐inhabiting) bryophytes have some of the fastest generation times for terrestrial plants. Considering these advantages, we investigated the demographic consequences of seasonality in precipitation during one‐year of the epiphyllous bryophyte Radula flaccida Gott. (Radulaceae) in a central Amazonian rain forest. In a 1‐ha sized study area, 154 epiphyll colonies from 18 phorophytes of the understory shrub Naucleopsis ulei (Warb.) Ducke (Moraceae) were marked and colony growth, extinction, recolonization, as well as rates of sexual and asexual expression were measured in nine demographic censuses. The probability of survivorship decreased in the dry season due to the synergistic effects of both increased leaf fall (e.g., loss of occupied patches) and colony mortality on persisting leaves. Asexual expression also declined significantly during the driest months; however, sexual expression, as measured by sporophyte density, was not related to seasonality. Logistic regression probabilities also indicate a minimum threshold colony size for optimal sporophyte expression. Lower survivorship and colony growth in the dry season along with reduced sporophyte production in smaller colonies implies that both demographic stability as well as population structure of Amazonian epiphyll species may be compromised whether climate models projecting prolonged droughts for the region are accurate.