Benjamin D. Hafner

Benjamin D. Hafner
Technische Universität München | TUM · School of Life Sciences Weihenstephan

Ph.D.

About

18
Publications
3,474
Reads
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169
Citations
Introduction
I am interested in forest trees' below-ground processes and their potential facilitative effects on forest ecosystems. My research focus currently lies on quantification of hydraulic redistribution between species and assessing the role of fine root exudation on carbon budgets of forest systems. I particularly use stable isotopes for my research and am experimenting with novel technologies such as microdialysis systems, laser ablation tomography or quantum dot technology.
Additional affiliations
October 2019 - February 2023
Cornell University
Position
  • Post Doc
Education
July 2015 - July 2020
Technische Universität München
Field of study
  • Forest Science
September 2012 - April 2015
Technische Universität München
Field of study
  • Forest- and Wood Science
September 2009 - April 2013
Technische Universität München
Field of study
  • Forestry and Resource Management

Publications

Publications (18)
Article
Full-text available
Traditionally, fine roots were grouped using arbitrary size categories, rarely capturing the heterogeneity in physiology, morphology and functionality among different fine root orders. Fine roots with different functional roles are rarely separated in microbiome‐focused studies and may result in confounding microbial signals and host‐filtering acro...
Article
Water consumption of trees is one of the most important processes connected to their survival under ongoing climate change and extreme events such as drought. Radial profiles of xylem sap flow density are an integral component to quantify the water transport for the level of an individual tree and that of ecosystems. However, knowledge of such radi...
Article
As climate change progresses, the frequency and duration of drought stress events are increasing. While the mechanisms of drought acclimation of trees received considerable attention in recent years, the recovery processes remain critically understudied. We used a unique throughfall exclusion experiment in a mature temperate mixed forest consisting...
Article
Full-text available
After drought events, tree recovery depends on sufficient carbon (C) allocation to the sink organs. The present study aimed to elucidate dynamics of tree‐level C sink activity and allocation of recent photoassimilates (Cnew) and stored C in c. 70‐year‐old Norway spruce (Picea abies) trees during a four week period after drought release. We conducte...
Article
Full-text available
Carbon (C) exuded via roots is proposed to increase under drought and facilitate important ecosystem functions. However, it is unknown how exudate quantities relate to the total C budget of a drought‐stressed tree, that is, how much of net‐C assimilation is allocated to exudation at the tree level. We calculated the proportion of daily C assimilati...
Data
File List: BrunnHafner_Ex_Roots_Properties.csv - root characteristics (mass, tips, area) and exudation rates of sampled root branches. BrunnHafner_Soil_Moisture_KROOF.csv - volumetric soil moisture in 2 soil depth increments BrunnHafner_Root_Properties_KROOF.csv - root characteristics (mass, tips, area) and core volume of cores taken for tree leve...
Presentation
Drought is a severe natural risk that increases drying-rewetting frequencies of soils. Yet, it remains largely unknown how forest ecosystems respond to dry-wet cycles, hampering our ability to evaluate the overall sink and source functionality for this large carbon pool. Recent investigations suggest that the release of soluble carbon via root exud...
Article
Full-text available
The Kroof experiment: realization and efficacy of a recurrent drought experiment plus recovery in a beech/spruce forest. Ecosphere 12(3): Abstract. Forest ecosystems play a central role in global water and carbon cycles, yet the impact of global climate change, in particular drought, on trees and forests is poorly understood. Therefore, there is an...
Article
Full-text available
Hydraulic redistribution (HR) can buffer drought events of tree individuals, however its relevance for neighboring trees remains unclear. Here, we quantified HR to neighboring trees in single‐ and mixed‐species combinations. We hypothesized that uptake of HR water positively correlates with root length, number of root tips and root xylem hydraulic...
Article
Full-text available
Hydraulic redistribution (HR) of soil water through plant roots is widely described, however its extent, especially in temperate trees, remains unclear. Here, we quantified HR of five temperate tree species. We hypothesized that both, HR within a plant and into the soil increase with higher water-potential gradients, larger root conduit diameters a...
Article
Full-text available
Hydraulic redistribution (HR), the passive reallocation of water along plant structures following a water potential gradient, is an important mechanism for plant survival under drought. For example, trees with deeper roots reallocate water from deeper moist to shallower, drier soil layers sustaining their upper fine root system. The relevance of HR...
Presentation
Climate change will lead to a warmer and drier climate in Central Europe, together with more frequent extreme events. Mixed species forests are expected to have a higher resistance against such climatic challenges. One mechanism behind this might be hydraulic redistribution (HR). Under dry conditions, trees with deeper roots reallocate water from m...
Poster
Hydraulic redistribution (HR) describes a passive flux of soil water through plant roots driven by soil-water potential gradients. Its influence on the water balance of plants and ecosystems depends on interactions between soil processes and the physiological and morphological behavior of plants. This contribution comprises field and greenhouse exp...
Article
Full-text available
Hooves preserve the isotopic information laid down during their growth and may be used for reconstruction of animal feeding history. To assign certain positions along hooves to corresponding times, growth rates are required. Hoof growth rates are known for domestic animals; however, they cannot be obtained easily in wild animals. We estimated the h...
Data
We measured isotopic composition (13C, 15N) along hooves of the European roe deer (Capreolus capreolus L.). In addition we provide rumen content analysis data.
Article
Hydraulic redistribution (HR) of soil water through plant roots is a crucial phenomenon improving the water balance of plants and ecosystems. It is mostly described under severe drought, and not yet studied under moderate drought. We tested the potential of HR under moderate drought, hypothesizing that (H1) tree species redistribute soil water in t...

Network

Cited By
    • Institute of Dendrology Polish Academy of Sciences
    • Swiss Federal Institute for Forest, Snow and Landscape Research WSL
    • Swiss Federal Institute for Forest, Snow and Landscape Research WSL
    • Swiss Federal Institute for Forest, Snow and Landscape Research WSL
    • Institute of Dendrology PAS; Poznan University of Life Science