Convergence of ecophysiological traits drives floristic composition of early lineage vascular plants in a tropical forest floor
Convergence of ecophysiological traits drives floristic composition of early lineage vascular plants in a tropical forest floor
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生态生理特征的趋同驱动热带森林地面早期维管束植物的区系组成
DOI：
10.1093/aob/mcy210
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发表时间：
2018
期刊：
影响因子：
4.2
通讯作者：
Watkins, James E
中科院分区：
文献类型：
--
作者：
Campany, Courtney E;Martin, Lindsay;Watkins, James E
背景和目的热带林下植物群落是高度多样化的，其特征是可变的资源可用性，特别是光。在这些竞争环境中的植物必须仔细分配资源，以确保生态和进化的成功。有效资源分配的一个机制是优化功能性状，以增强高度异质性生境中的竞争。在这里，我们调查了两个早期谱系维管植物群从热带森林下层：卷柏（石松植物的不同血统）和ferns.MethodsIn一个低地雨林在哥斯达黎加，我们测量了一套功能特性从7种ofSelaginella和6蕨类植物。我们评估了物种的小气候和栖息地;几个光合参数;碳，氮和磷含量;叶绿素浓度;叶质量单位面积（LMA）;气孔大小和密度。然后，我们比较这两种植物的谱系和搜索的关键功能参数之间的关系，已经存在于全球范围内的被子植物。关键结果收敛的性状功能filteredSelaginellaspecies到不同的栖息地，在严重阴影的环境中的物种有较高的叶绿素浓度和较低的光补偿点相比，开放的栖息地。另外，在占据这些开放栖息地的物种中检测到较低的叶片氮和较高的气孔密度。卷柏属物种的气孔密度和较小的气孔，较低的LMA和较低的叶片养分含量比蕨类植物，揭示了这些植物群体如何优化生态生理功能在热带森林floor. Conclusions我们的研究结果增加了关键的缺失证据，以全球探索定义维管植物形式和功能的特征模式，主要集中在种子植物上。广泛的可预测的功能性状的关系，检测到横跨bothSelaginella和蕨类植物，类似于种子植物。然而，进化渠化的小叶叶发育似乎已经驱动对比，但成功的，生态生理学的战略，两个共存的谱系现存的同孢维管植物。
Background and AimsTropical understorey plant communities are highly diverse and characterized by variable resource availability, especially light. Plants in these competitive environments must carefully partition resources to ensure ecological and evolutionary success. One mechanism of effective resource partitioning is the optimization of functional traits to enhance competition in highly heterogeneous habitats. Here, we surveyed the ecophysiology of two early lineage vascular plant groups from a tropical forest understorey:Selaginella(a diverse lineage of lycophytes) and ferns.MethodsIn a lowland rain forest in Costa Rica, we measured a suite of functional traits from seven species ofSelaginellaand six fern species. We evaluated species microclimate and habitat; several photosynthetic parameters; carbon, nitrogen and phosphorus content; chlorophyll concentration; leaf mass per area (LMA); and stomatal size and density. We then compare these two plant lineages and search for relationships between key functional parameters that already exist on a global scale for angiosperms.Key ResultsConvergence of trait function filteredSelaginellaspecies into different habitats, with species in heavily shaded environments having higher chlorophyll concentrations and lower light compensation points compared with open habitats. Alternatively, lower foliar nitrogen and higher stomatal densities were detected in species occupying these open habitats.Selaginellaspecies had denser and smaller stomata, lower LMA and lower foliar nutrient content than ferns, revealing how these plant groups optimize ecophysiological function differently in tropical forest floors.ConclusionsOur findings add key pieces of missing evidence to global explorations of trait patterns that define vascular plant form and function, which largely focus on seed plants. Broadly predictable functional trait relationships were detected across bothSelaginellaand ferns, similar to those of seed plants. However, evolutionary canalization of microphyll leaf development appears to have driven contrasting, yet successful, ecophysiological strategies for two coexisting lineages of extant homosporous vascular plants.