Microenvironmental drivers of plant community dynamics

PhD project

This project will investigate two core aspects of fine-scale species interactions: modification of microclimate, and modification of dispersal processes. The project will address these questions in two long-term study sites, one Berkeley-led site in the Rocky Mountains (USA), and one NTNU-led site at Dovrefjell (Norway) related to the three ECOSHRUB-sites. In each, the PIs will ask:

1. How does the extant vegetation affect the microclimate of microsites for seedling recruitment?
2. How does the extant vegetation, in particular shrubs, affect seed dispersal?

Methods will be based on resurveying long-term demographic research sites, field-based experiments, and mapping the microclimatic landscape with microclimate loggers and thermal photographs. Through this work, the project will support reciprocal international exchange of a USA-based and Norway-based graduate student.

Time frame: Start 2020

Who is involved:
Courtenay Ray
Benjamin Blonder
Bente Jessen Graae
Richard Strimbeck

How do willow shrubs and lichens affect the microclimate for other plants?

Master project

Climate change is one of the biggest problems that we are facing nowadays. Alpine environments are among the most threatened by the effects of climate change because the organisms that live there are conditioned to low temperatures. Among the many observed changes in these environments, shrub encroachment is one of the most evident. Many studies have shown that this encroachment is affecting cryptograms reducing their abundance.

Microclimate is the actual temperature that the organism is experiencing. Studies have shown that microclimate can impact community structure and its dynamics over time. Moreover, community structure can affect the microclimate via organisms’ interactions. An organism can modify its microclimate and make it more favorable or unfavorable for other species. Little is known about how functional groups of established plants affect the microclimate. In this project, we will study how willow shrubs and cryptogams, in this case, lichens, affect the microclimate through the use of thermal imaging.

Time frame: Start 2020, end 2022

Who is involved:
Domenica Naranjo
Richard Strimbeck
Bente Jessen Graae

Determinants of tree seedling establishment in alpine tundra

Master project

In this project we assessed the invasibility of the alpine tundra ecosystem by Scots pine (Pinus sylvestris) and the way in which disturbance, herbivore presence and shrub introduction modify invasibility of different alpine plant communities. We also aimed to assess the role of microclimate in this process. Invasibility was measured as emergence, survival and performance of Scots pine. Results showed that pine is able to establish above their elevational limit and that disturbance and herbivory are the most important determinants for pine invasion.

Time frame: Start April 2018, end January 2019

Who is involved:
Juul Limpens
Bente Jessen Graae
Pieter De Frenne

Drivers of plant recruitment in alpine vegetation

PhD project

We study the interactive effects of willow shrub expansion and herbivory on the recruitment phase of plants in alpine plant communities. We have sown seeds of 14 vascular plants (including trees, shrubs, dwarf shrubs, graminoids and forbs) into plots with and without vegetation removal and recorded seedling emergence and survival over three years in a low-alpine meadow, heath and willow shrub. We also investigate how the recruitment phase is linked to microclimate and plant traits. We aim to learn more about seedling recruitment in the alpine and tell which plants are winners and losers under shrub expansion.

Time frame: Start 2013, end 2020.
 

Who is involved:
Kristin Odden Nystuen 
Bente Jessen Graae 
Håkon Holien

Effects of lichens on seedling recruitment

Master project

​​​​​​In this project we look at how species of lichens, common in the Dovre Mountains, affect germination and emergence of vascular plants. Despite of the large areas of lichens covered in Dovre, lichens are said to decline while vascular plants increase. We therefore want to investigate the chemical and physical properties of the lichens that might affect the micro site where the vascular plants establish. Do the lichens facilitate or inhibit germination? And is the effect of the lichens dependent on the vascular plants species?

Time frame: Start 2014, end June 2016.

Who is involved:
Kristine Sundsdal
Kristin Odden Nystuen 
Bente Jessen Graae 
Richard Strimbeck 

Shrub encroachment in alpine communities

Master project

In this project we look at the effects of shrub enchroachment on the microclimate of three vegetation types: heath, meadow and willow. Do shrubs (height of vegetation, percentage cover of shrubs etc) have an effect on the microclimate. The effect of herbivory on the microclimate is also examined by means of exclosures.

Time frame: Start May 2015, end January 2016.

Who is involved:
Andreas Baele
Pieter de Frenne
Bente Jessen Graae 
Mia Vedel Sørensen

Floristic description of three alpine plant communities 

Bachelor project

This project is a description of our study area in general and the flora, including vascular plants, bryophytes and lichens, in three plant communities with experimental plots used by other people in the group.

Time frame: Start July 2014, end May 2015

Who is involved:
Karl Andreas Johannessen
Kristin Odden Nystuen
Håkon Holien

Leaf trait characteristics in three alpine plant communities

Bachelor project

The project describes and compares three alpine plant communities by looking at between-species and among-species variation in different plant traits.

Time frame: Start July 2014, end May 2015

Who is involved:
Simen Dille 
Kristin Odden Nystuen 
Håkon Holien 

The effects of microclimatic variations on the recruitment of plant species in arctic and alpine ecosystems

Master project

In this project we look at the influence of microclimate on seedling recruitment. The main focus of the research is to answer the following research question: How does microclimate affect seedling recruitment in three representative alpine plant communities? In the field we made an inventory of the seedlings and measured the soil moisture, light availability and soil temperature. With this data we can look at the effects of microclimate on seedling recruitment.

Time frame: Start April 2016, end December 2016

Who is involved:
Nick Stam
Juul Limpens
Pieter De Frenne
Kristin Odden Nystuen

The effects of microclimatic variation on plant traits

Master project

In this project we relate plant functional traits to the complex microclimate of the changing alpine tundra to predict adaptation of general and community specific plant species.

Time frame:Start April 2016, end December 2016

Who is involved:
Lars Uphus
Juul Limpens
Pieter De Frenne
Kristin Odden Nystuen