Hubei Key Laboratory of Economic Forest Germplasm Improvement and Resources Comprehensive Utilization, Hubei Collaborative Innovation Center for the Characteristic Resources Exploitation of Dabie Mountains, Huanggang Normal University, Huanggang 438000, Hubei, China.
CAS Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, Hubei, China; Center of Conservation Biology, Core Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, Hubei, China.
Sci Total Environ. 2021 Feb 25;757:143819. doi: 10.1016/j.scitotenv.2020.143819. Epub 2020 Nov 18.
Environmental heterogeneity in resource availability affects invasive plant reproductive strategies and resource allocation to reproduction. Here, we conducted two field surveys to examine the effect of wetland and terrestrial habitats on inflorescence production and resource allocation to inflorescence of the amphibious invasive plant Alternanthera philoxeroides in its invasive range (China). We also specifically examined the effects of water availability, fertilizer application, and plant density (space) in a greenhouse experiment. In field surveys, inflorescence biomass, normal monoclinous flowers and ratio of inflorescences to shoots of plants from wetlands were about 2.4-, 0.8- and 1.3-fold higher than those from terrestrial habitats, respectively. In greenhouse experiment, plants with higher fertilizer application and lower competition conditions produced more inflorescences, and had a lower ratio of roots to shoots and a comparable ratio of inflorescences to shoot and root. Furthermore, water availability had a significant interactive effect when combined with fertilizer level or plant density on inflorescence production and resource allocation. Together, our results indicate that high resources, such as those found in wetland habitats, favor both vegetative growth and sexual trait in A. philoxeroides. However, in terrestrial habitats where resources are relatively poor, the invader can adapt to the environment by allocating more resources to vegetative growth for clonal reproduction and less resources for sexual trait. This phenotypic plasticity in resource allocation likely facilitates the plant to invade heterogeneous wetlands and terrestrial environments.
环境中资源可利用性的异质性会影响入侵植物的繁殖策略和资源分配到繁殖上。在这里，我们进行了两项野外调查，以研究湿地和陆地生境对入侵植物空心莲子草（Alternanthera philoxeroides）在其入侵范围内（中国）的花序产生和资源分配到花序的影响。我们还特别在温室实验中检查了水分可用性、施肥和植物密度（空间）的影响。在野外调查中，来自湿地的植物的花序生物量、正常的单性花和花序与芽的比例分别比来自陆地生境的植物高 2.4 倍、0.8 倍和 1.3 倍。在温室实验中，具有较高施肥水平和较低竞争条件的植物产生更多的花序，根与芽的比例较低，花序与芽和根的比例相当。此外，水分可用性与肥料水平或植物密度结合时，对花序产生和资源分配有显著的交互作用。总之，我们的研究结果表明，高资源，如湿地生境中的资源，有利于空心莲子草的营养生长和有性特征。然而，在资源相对较少的陆地生境中，入侵种可以通过将更多的资源分配到营养生长以进行无性繁殖，而将较少的资源分配到有性特征来适应环境。这种资源分配的表型可塑性可能有助于植物入侵异质的湿地和陆地环境。
