Dr. Helena JR Einzmann

Contact

Room: W4 0-049

Phone: +49 (0)441 798-3315

Email: helena.einzmann(at)uni-oldenburg.de

 

 

Research interests

  • Epiphyte assemblages of tropical forests and anthropogenic landscapes
  • Microclimatic influences on epiphyte assemblages
  • Influences of anthropogenic landscape changes on epiphyte assemblages

  • Mechanical effect of wind on epiphytes: how large is the force on epiphytes when exposed to wind?
  • What force is needed to detach an epiphyte from it's substrate?

    Project: Epiphytes and wind an changing world

    Epiphytes are a key element of tropical forests that are known as a cradle of biodiversity. Highly diverse themselves, epiphytes provide habitat and food for many dependent organisms and play a key role in the water and nutrient cycling of the ecosystem. Structurally depend on their host and growing at the interface between terrestrial vegetation and the atmosphere, they are tightly coupled to the atmosphere and hence much more affected to changes in any climate regime. Therefore, it is surprising how little is known about how wind affects epiphytes. The proposed project links biodiversity research with physics aiming to understand the effect of wind on the epiphytes` vital attachment to their host. This becomes even more important as their natural habitat, the tropical forests, are fragmented by land-use change, exposing them further, which potentiates the negative effects of climate change, e.g. intensification of strong storm events.

    With this project we want to identify the bottleneck in the epiphyte-host system, i.e. if wind is able to dislodge epiphytes from their substrate or if the substrate fails first. To do so subprojects were designed that study different aspects of the system:

    A descriptive study in several countries in the hurricane belt will identify the percentage of epiphytes dislodged from their host with and without the substrate after a storm. Although there are anecdotal statements in the literature that epiphytes were blown off, there is no quantitative study that identifies the actual bottleneck. This part will be done in cooperation with local colleagues.

    Despite the importance for epiphytes to stay attached to their substrate nothing is known about their ability to maintain this attachment. Two subprojects are designed as a collaboration with the wind researchers from the physics institute of Oldenburg University. With a series of experiments in the wind tunnel the force acting on epiphytes under wind stress will be measured and the force necessary to detach epiphytes from their substrate. If wind is unable to strip epiphytes from their substrate only the destruction of the entire system can threaten epiphyte community survival severely.

    The experiments in the wind tunnel will be complemented by the investigation of the mechanical properties of the epiphyte roots. To this end, their innate tensile and their attachment strength will be measured and the penetration depth of the root hairs into the substrate quantified. Lastly, it will be experimentally investigated if epiphytes show phenotypic plasticity by enhanced root growth due to a simulated constant wind pressure. In combination the subprojects will identify the bottleneck in the epiphyte-host system and allow an assessment of the consequences of land-use and climate change for a key element of tropical plant diversity.

    Publications

    Einzmann HJR & Zotz G. 2017. Dispersal and establishment of vascular epiphytes in human-modified landscapes. AoB Plants, 9: plx052. doi: https://doi.org/10.1093/aobpla/plx052.

    Einzmann HJR & Zotz G. 2017.  "No signs of saturation": long-term dynamics of vascular epiphyte communities in a human-modified landscape. Biodiversity and Conservation 26: 1393-1410. doi: 10.1007/s10531-017-1306-z.

    Zotz G, Weichgrebe T, Happatz H & Einzmann HJR. 2016. Measuring the terminal velocity of tiny diaspores. Seed Science Research 26: 222-230.

    Einzmann HJR, Döcke L & Zotz G. 2016. Epiphytes in human settlements in rural Panama. Plant Ecology & Diversity 9: 277–287.

    Einzmann HJR & Zotz G. 2016. How diverse are epiphyte assemblages in plantations and secondary forests in tropical lowlands? Tropical Conservation Science 9: 629-647.

    Einzmann HJR, Beyschlag J, Hofhansl F, Wanek W & Zotz G. 2015. Host tree phenology affects vascular epiphytes at the physiological, demographic and community level. AoB Plants 7: plu073. doi:10.1093/aobpla/plu073

    Surina B, Pfanzelt S, Einzmann HJR & Albach DC. 2014. Bridging the Alps and the Middle East: Evolution, phylogeny and systematics of the genus Wulfenia (Plantaginaceae). Taxon 63: 843-858.

    Other publications (not reviewed)

    Einzmann HJR, Döcke L & Zotz G. 2016. Epiphytes in human-modified landscapes. What's Up? 22: 6-7.

    Curriculum vitae

    since November 2016
    Scientific staff, University Oldenburg
    Oct. 2011 – Jul. 2016

    PhD, Carl von Ossietzky University Oldenburg

    Thesis (magna cum laude): Epiphytes in human-modified landscapes“

     

    Nov. 2015 – Feb. 2016
    Scientific staff, University Oldenburg
    Oct. 2014 – Aug. 2015
    Scientific staff, University Oldenburg
    May 2014 – Aug. 2014
    Scientific staff / teaching assistant, University Oldenburg
    May 2013 – Dec. 2013
    Scientific staff, University Oldenburg
    Jul. 2012 – Dec. 2012
    Scientific staff, University Oldenburg
    Oct. 2010 – Dec. 2011

    Scientific staff / teaching assistant, University Oldenburg

     

    Oct. 2005 – Sep. 2010

    Biology studies, Carl von Ossietzky University Oldenburg

    Sep. 2008
    Bachelor of Science - Biology

    Thesis: Funktionelle Untersuchungen an Pseudobulben“

    Oct. 2010

    Master of Science - Biology

    Thesis: “Investigation of epiphyte communities of deciduous and evergreen trees in a tropical lowland forest”

    Contributions to scientific congresses

    Einzmann HJR, Döcke L & Zotz G. 2016. Epiphytes in Human-Modified Landscapes. Oral presentation at the 7th International Canopy Conference. August 21st-26th 2016, London, UK.

    Einzmann HJR & Zotz G. 2015. Epiphytes in Human-Modified Landscapes: Dispersal and Establishment. Poster at the 45th Annual Conference of the Ecological Society of Germany, Austria and Switzerland. September 31st-4th 2015, Göttingen, GER.

    Pfanzelt S, Surina B, Einzmann HJR & Albach D. 2012. Bridging the Alps and the Middle East: Phylogeny and systematics of the genus Wulfenia Jacq. (Plantaginaceae). Oral presentation at the 21st International Symposium "Biodiversity and Evolutionary Biology" of th German Botanical Society (DBG), September 16th-19th 2012, Mainz, GER.

    Einzmann HJR & Zotz G. 2012. "Oh, how beautiful is Panama?" - The epiphyte's perspective. Poster at the 42nd Annual Meeting of the Ecological Society of Germany, Austria and Switzerland, September 10th-14th 2012, Lüneburg, GER.

    Einzmann HJR, Beyschlag J, Wanek W & Zotz G. 2011. Host tree phenology affects epiphyte assemblages. Oral presentation at the 41st Annual Meeting of the Ecological Society of Germany, Austria and Switzerland, September 5th-9th 2011, Oldenburg, GER.

    Einzmann HJR, Beyschlag J, Wanek W & Zotz G. 2011. On the sunny side - epiphyte assemblages of deciduous and evergreen trees in a tropical lowland forest. Poster at the Annual Conference of the Society for Tropical Ecology, February 21st-24th 2011, Frankfurt a. M., GER.