Plant-soil feedbacks in European temperate trees
BORIS DOI
Abstract
The interactions of plants with soil microbes i.e. plant-soil feedbacks interfere with many different ecological aspects and concepts (invasion ecology, species coexistence, species diversity etc.). In this thesis I experimentally investigate different levels of plant-soil feedback in several European temperate tree species, feedbacks between different tree species, between different populations of the same species, and between individuals within a population. The thesis consists of five chapters. Chapter 1 gives a general introduction to the topic. Chapters 2-4 report on three plant soil-feedback common garden experiments with the corresponding results presented and discussed in the format of scientific publications with the following topics: In Chapter 2¸ I study plant-soil feedbacks of 17 European temperate tree species. I investigate possible factors influencing the strength of plant-soil feedbacks, such as the type of mycorrhizal fungi a tree is associated with or whether a tree grows fast or slow. The major novelty of this chapter is based on its combination of several ecological concepts (growth-defence trade-off with Janzen-Connell effects). Furthermore, this is the most comprehensive study to date of plant-soil feedbacks in European temperate forests in terms of the number of tree species studied simultaneously.
In Chapter 3, I then focus on the first within-species level, i.e. on variation in plant-soil feedback strength between populations. Specifically, I examine whether six tree species perform worse or better when growing with soil biota from their own and from a different population. While there is some evidence of negative intraspecific plant-soil feedbacks for tropical and subtropical forests, few such studies exist for temperate forests, and some of them show opposite results to the tropical studies, arguing for the sympatric advantage hypothesis. I discuss the relationship between intraspecific plant-soil feedbacks and local adaptation and what important implications this may have for both ecology and forestry. In Chapter 4 I go one step further and investigate plant-soil feedbacks within populations of five different European tree species. Studies that address plant-soil feedbacks within populations are very rare and yet important. So far, no other study has investigated the plant-soil feedbacks for different tem-perate tree species simultaneously. In this chapter, I show what we can learn from including the within-population level in the study of plant-soil feedbacks and what implications such feedbacks might have for science and forest man-agement. In Chapter V, I summarise the whole work, compare plant-soil feedbacks at the between-tree, between-population and between-species levels. I discuss why mutualists deserve as much consideration in plant-soil feedback studies as pathogens. Furthermore, I focus on how far intra- and interspecific plant-soil feedbacks are comparable and what we can learn from including the dif-ferent levels. Furthermore, I show how not considering these different levels can confound the interpretation of plant-soil feedback studies. Last but not least, I draw my general conclusions for science and application.
In Chapter 3, I then focus on the first within-species level, i.e. on variation in plant-soil feedback strength between populations. Specifically, I examine whether six tree species perform worse or better when growing with soil biota from their own and from a different population. While there is some evidence of negative intraspecific plant-soil feedbacks for tropical and subtropical forests, few such studies exist for temperate forests, and some of them show opposite results to the tropical studies, arguing for the sympatric advantage hypothesis. I discuss the relationship between intraspecific plant-soil feedbacks and local adaptation and what important implications this may have for both ecology and forestry. In Chapter 4 I go one step further and investigate plant-soil feedbacks within populations of five different European tree species. Studies that address plant-soil feedbacks within populations are very rare and yet important. So far, no other study has investigated the plant-soil feedbacks for different tem-perate tree species simultaneously. In this chapter, I show what we can learn from including the within-population level in the study of plant-soil feedbacks and what implications such feedbacks might have for science and forest man-agement. In Chapter V, I summarise the whole work, compare plant-soil feedbacks at the between-tree, between-population and between-species levels. I discuss why mutualists deserve as much consideration in plant-soil feedback studies as pathogens. Furthermore, I focus on how far intra- and interspecific plant-soil feedbacks are comparable and what we can learn from including the dif-ferent levels. Furthermore, I show how not considering these different levels can confound the interpretation of plant-soil feedback studies. Last but not least, I draw my general conclusions for science and application.
Date of Publication
2023
Year of graduation
2023
Theses Type
dissertation
Language(s)
en
Author(s)
Faculty/Graduate School
Institute
Access(Rights)
open.access
Primary OA Publication
true