Nutrient Foraging by Mycorrhizal Roots of Different Morphology: Are Roots and Fungi Complementary?

影响不同植物中养分觅食的根特征还知之甚少。在大多数植物中，根与菌根真菌形成共生关系，这可能会提高植物寻找营养的能力。然而，不同物种在菌根有利于养分吸收的程度上存在差异，这可能与根的形态有关，包括根的直径和根毛的丰度。PI假设，根毛很少或很短的粗根树种通过严重依赖菌根真菌在营养丰富的斑块中觅食，而根生长较快的树种通过繁殖根部、增加根毛发育和改变养分吸收速度来寻找养分。该项目将主要在14年种植16种不同的树种，这些树种的根形态差异很大，尽管将在天然林木和生长室中进行额外的研究。这项研究将完善植物根系用于计算植被对元素循环的影响的理论基础，改进对植被对气候变化的响应和反馈的预测，并增加对植物根系的理解，以更好地管理作物和树木作为食物和纤维。这项研究将有很强的教育成分，包括三名研究生的培训、本科生研究培训以及学生和科学家的国际交流。

Root traits that influence nutrient foraging in different plants are poorly understood. In most plants, roots form a symbiotic association with mycorrhizal fungi that may improve the ability of the plant to forage for nutrients. However, species differ in the extent that mycorrhizae can benefit nutrient uptake, and this is likely related to root morphology, including root diameter and root hair abundance. The PIs hypothesize that tree species with coarse roots with few or short root hairs forage in nutrient-rich patches by relying heavily on mycorrhizal fungi, while tree species with more rapidly growing roots that produce many long root hairs forage for nutrients by proliferating their roots, increasing root hair development and altering the rate of nutrient uptake. The project will be primarily conducted in a 14-year-old planting of 16 different tree species that vary widely in root morphology, although additional studies will be conducted in natural forest stands and in growth chambers. This study will improve the theoretical basis by which plant roots can be used for calculating the influence of vegetation on elemental cycles, improve predictions of vegetation responses and feedbacks to climate change, and increase the understanding of roots needed for better management of crops and trees for food and fiber. There will be a strong educational component to this research, including the training of three graduate students, undergraduate training in research and international exchanges of students and scientists.