Lichen phenotypic adaptations to exposure and presence of vascular plants (MSc project)

Beginning:      Autumn-Winter 2019-2020
Duration:        20 – 30 weeks, unpaid
Credits:            30 – 45 ETC

Background

Alien species can have large impacts on ecosystems but their impact on polar ecosystems is poorly researched and thus not well understood. Polar ecosystems, especially those in Antarctica, include some of the most simplified food webs on Earth with only a few key species driving ecosystem processes. They are sensitive and vulnerable to invasion, with alien species likely to quickly seize key roles and affect ecosystem functioning. In addition, alien species may facilitate the growth of native vegetation, as shelter is an important aspect for survival in the harsh Antarctic climate. As such, lichens and mosses, the dominant vegetation in Antarctica, may benefit from alien plant species due to the shelter they provide.

Because we are not allowed, under the Antarctic Treaty regulations, to introduce non-native species to the Antarctic we have applied alternative methods to quantify the impact of alien plants species on Antarctic lichen communities. We have set up artificial versions of vascular plants in the field near Antarctic lichens to measure impacts on lichen growth and physiology (see picture below). However, due to the low temperature and slow growth of Antarctic lichens we also want to quantify the response of these lichens to the presence of vascular plants at a site where they already occur together, such as can be found in mountainous regions of southern Chile.

Project

During this project you can join our fieldwork in southern Chile planned for January 2020, where we will quantify the impact of exposure to light intensity (north versus south facing slopes) and shade/shelter provided by vascular plants (grasses and shrubs) on the growth morphology and physiology of lichens. This work will be done on mountain slopes near Puerto Williams which resemble vegetation characteristics along the Antarctic Peninsula region. This work will provide valuable insights into the response of lichens if new vascular plant species will establish on the Antarctic Peninsula.

Artificial ‘invasive’ plant established on Anchorage Island (67 °S) to quantify impacts of vascular plants on Antarctic lichens in the field.


Fell-field lichen vegetation at the top of Cerro Bandera (Puerto Williams, Chile). The lichen at the forefront is an Usnea species which also grows along the Antarctic Peninsula region but here growing next to cushion plants and the dwarf shrub Empetrum rubrum.

Requirements

Willingness and ability to work in mountainous regions under adverse weather.

Please note that we are unable to support flight and accommodation costs (approximate costs @ 3.000 euro).

What will you learn

  • Gain practical experience in field ecology in mountainous regions and fell-field ecosystems.
  • How to quantify lichen morphological traits (STA, thallus thickness, volume, etc.).
  • How to measure lichen evaporation, photosynthesis and respiration using an IRGA under different light regimes.
  • Analytical skills in nitrogen and chlorophyll measurements.

Contact information

Stef Bokhorst is a researcher at the Department of Ecological Science working on climate change impacts and the role of invasive species in polar regions.
Alternative contact: Prof. Rien Aerts

If this topic appeals to you, please email s.f.bokhorst@vu.nl.
Faculty of Science, VU Amsterdam.
Dept. of Ecological Science, subdept. Systems Ecology, room A-159.
Address: De Boelelaan 1085, 1081 HV Amsterdam