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Projekte

Phenology of tropical trees

 

Phenology of tropical tree species – environmental cues, molecular mechanisms, and consequences for plant-animal interactions (2021 – 2027)

 

PhenologyIn the project, we will investigate the causes and consequences of regular and synchronized phenological transitions in tropical tree species. Investigating tropical tree phenology requires an integrative approach that takes into account the monitoring of tree phenology, molecular methods to study gene expression, and ecological approaches to study plant-animal interactions.

The study will be carried out in the montane humid forests and the seasonally dry tropical forest of Southern Ecuador, at the research stations Estacíon Científica San Francísco and Estacíon Científica Laipuna. Here, available data from previous and ongoing projects (most importantly from the research Emmy NoetherunitRESPECT) and continuous measurements of important parameters such as climate and carbon flux provide an ideal basis for realizing a study on tree phenology. During this project, we will simultaneously monitor phenological transitions, changes of gene expression, stem diameter variation, optical properties of canopies in four tree species and link this to carbon fluxes and climatic parameters. Thereby, this project will provide insights on how phenological transitions are triggered, which gene regulatory networks are involved in phenological transitions, and how these influence plant growth and carbon sequestration. Further, we will study the interdependencies of trees and their mutualistic and antagonistic partners in the light of phenological transitions. First, we will investigate pollinator assemblages, pollen-mediated gene flow, seed set, and germination rates. Second, we will investigate associated herbivore assemblages and rates of herbivory over time. Overall, this project will make important contributions to future predictions of the impact of climate change on montane rainforests.

The project is funded as an Emmy Noether research group by the DFG (HE 7345/8-1).

 

epiSOMA


 Causes and consequences of epigenetic diversity in trees (2022 – 2025)

 

epiSOMATrees are emerging as powerful ‘model systems’ to investigate epimutational processes in plants. Given their exceptional longevity, trees act as natural (epi)mutation accumulation systems and permit unprecedented insights into the dynamics, mitotic stability, and functional impact of spontaneous epimutations over time-frames that have been inaccessible to previous prospective studies. Focusing on European beech (Fagus sylvatica) as a model, we will combine unique experimental tree resources, proximate-sensing technology, multi-omic assays, and novel analytical tools to quantify how somatic epimutations alongside micro-environmental factors shape epigenetic and functional diversity within the 3D-topology of a tree, and how this intra-tree variation affects seeds and seedling performance in the next generation.

The BMBF funded project is coordinated by Frank Johannes (TUM), and in collaboration with Lars Opgenoorth (Universität Marburg) and Hans Pretzsch (TUM).

Reassembly

Reassembly of interaction networks - Resistance, resilience and functional recovery of a rainforest ecosystem (2021 – 2025)

 

NothofagusWe will investigate a chronosequence (forest sites recovering for different time spans from a former use as pasture or plantation) to assess and compare the reassembly of interaction networks and trajectories of ecosystem processes. We will quantify the effects of functional traits that are predicted to be important for network reassembly and resilience to perturbations: response traits to environmental conditions, and interaction traits as determinants of network links.

Overall, our research unit will unravel how, to what extent, and how fast a forest ecosystem can re-establish after deforestation, including the diverse species communities, complex interaction networks, and relevant processes that characterize such forest ecosystems.

Interaction between speciesThe research site is located in the Chocó lowland forest of North-West Ecuador in collaboration with Fundación Jocotoco, a private Ecuadorian conservation foundation. Sites include the Canandé Reserve and Tesoro Escondido Reserve.

Together with Nina Farwig (Marburg) and Sybille Unsicker (Jena), I will be responsible for subproject 5,  studying seedling recruitment along the chronosequence. Specifically, we focus on the dynamics of tree seedling-herbivore interactions during forest recovery.

The research unit is coordinated by Nico Blüthgen (Darmstadt) & funded by the DFG (HE 7345/11-1).

More information can be found on our project website and on Twitter.

FORGENIUS

Improving access to FORest GENetic resources Information and services for end-Users (2021 – 2025)

FORGENIUSIn this project, our European consortium with 19 partners from 12 countries will develop methods and tools to provide greater insight into the characteristics and the value of all forest-relevant collections of genetic resources presently existing in 35 European countries. The overall goal of FORGENIUS is to produce a new high-throughput quantitative assessment of conserved forest genetic resources and make it accessible to end-users by developing general standards, tools, and services for better characterization and management of the entire GCU collection.
The H2020 project is coordinated by Ivan Scotti (INRAE Avignon, France).

LocalAdapt

Local adaptation of Nothofagus pumilio along the latitudinal gradient of the Andes (2018 – 2023)

 

NothofagusIn this collaborative project, we investigate the local adaptation of Nothofagus pumilio along extreme latitudinal, elevational, and precipitation gradients. We have collected genetic and dendrophenotypic data along the latitudinal gradient of the Andes, and investigated gene flow in one intensive study sites. For the exome capture design, we used a transcriptome we assembled based on RNAseq data from a preliminary study with seedlings grown under different temperatures and day length conditions. Here, we determine whether genes involved in the regulation of circadian clock are differentially expressed in N. pumilio seedlings grown under different temperature regimes.

The collaboration with the team from INTA Bariloche was funded by the DAAD and Trees4future and is currently funded by the DFG (HE 7345/6-1). Check out the project website.

Publications

Sekely J, Marchelli P, Arana V, Dauphin B, Mattera MG, Pastorino M, Scotti I, Soliani C, Heer K, Opgenoorth L (2024) Genomic Responses to Climate: Understanding local adaptation in the Andean tree species Nothofagus pumilio and implications for a changing world. Accepted in Plants People Planet.

Estravis-Barcala M, Heer K, Marchelli P, Ziegenhagen B, Arana MV, Bellora N. (2021) Deciphering the transcriptomic regulation of heat stress responses in Nothofagus pumilio. PLoS ONE 16(3): e0246615. https://doi.org/10.1371/journal.pone.0246615

Estravis-Barcala M, Mattera MG, Soliani S, Bellora N, Opgenoorth L, Heer K, Arana MV (2020) Molecular bases of responses to abiotic stress in trees. Journal of Experimental Botany, 71(13), 3765–3779. https://doi.org/10.1093/jxb/erz532

TREEvolution

 

Diversity and management effects on forest evolution (2023 – 2026)

 

Beech leavesIn this project, we aim to investigate the genomic diversity dynamics of beech (Fagus sylvatica) in order to estimate the effect of natural selection in populations among life stages (seedlings, saplings, and adult trees) across a large representative sample using all beech-containing Experimental Forest Plots

The project is funded in the framework of the SPP Biodiversity Exploratories (HE7345/12-1) and carried out in collaboration with Dr. Mona Schreiber, Dr. Christian Lampei and Prof. Dr. Lars Opgenoorth (all Philipps University Marburg)

PhytOakmeter

 

Using clonal oak phytometers to unravel acclimation and adaptation mechanisms of long-lived forest tree holobionts to ecological variations and climate change (2023 – 2026)

 

PhytOakMeter_Kreis_273dpi.png

Climate change and global species loss are the major environmental threats to human well-being in the coming decades. However, despite more than 200 years of organized forestry and research in temperate forests, some fundamental knowledge is still missing about (i) the phenotypic plasticity of forest trees, (ii) about the interplay of trees with their microbiome, and (iii) about how these interactions may facilitate acclimation (regulatory changes) and adaptation based on genetic changes of trees and/or their holobiont partners. In this light, we have assembled a group of experts in (population) genetics, epigenetics, transcriptomics, metabolomics as well as in tree physiology and morphology working on a wide range of organisms from bacteria to trees to investigate a tree holobiont. We focus on Quercus robur L., a foundation species of European forests with a long lifespan and broad geographical distribution and an exceptionally high diversity of biotrophic interactions. A central benefit of working with Q. robur is the availability of the DF159 clone that is readily in-vitro propagated in large numbers. This resource allows us to exclude genetic variability of the tree host in order to disentangle the role of the holobiont partners in the acclimation and adaptation processes of the oak holobiont. In PHASE I of the RU, the subprojects SP1 – SP7 will mainly work on three experimental platforms with the clone DF159 to

(i) perform controlled experiments in two Ecotrons that expose the holobiont to two moderate droughts (previous year and current year for longer-term stress memory, spring and summer for shorter term stress memory) and above- and below-ground herbivory, respectively;

(ii) expose oak clonal saplings to the microclimatic variability of the canopy of mature trees; and

(iii) assess clonal oak saplings released across Germany and Europe for analyzing A&A mechanisms under a wide range of environmental conditions.

The research unit is funded by the DFG, and coordinated by Prof. Dr. Lars Opgenoorth (University Marburg).

For more details on the project and the subprojects, please have a look at our website.