Cushion plant effects on seed germination in an alpine environment

Amanda Liczner MSc. candidate

Presentation topics

Introduction

What is facilitation

Purpose, hypothesis

Methods

Field collection

Germination trials

Results

Implications

Introduction: facilitation is positive interactions between species

Bruno et al. 2003, Brooker et al. 2008

A B

A B

Introduction: nurse effects on beneficiary species

Temperature

Soil moisture

Soil nutrients

Wind

UV radiation

Cavieres et al. 2008; le Roux and McGeoch 2010; Anthelme et al 2012; Molenda et al 2012; Schoeb et al 2012

Purpose: to determine the influence of cushions on germination

Question: do seeds from open plants have greater germination in cushions?

Hypothesis: seeds from species in the open will benefit from decreased abiotic stress and thus will have greater germination within the cushion

Predictions:1. Plant height will be greater in the cushion2. Seed germination will be greater in the cushion3. Seeds will germinate faster in the open

Methods: surveyed cushion-open paired sites

Plant density of beneficiaries in cushion and openMeasured average plant height of beneficiaries

Methods: seeds were collected for germination trials

Seeds (10/species)

cushion chambers

open chambers

Methods: germination trials were conducted for 14d

Methods: germination trials were conducted for 14d

Results: plant density is greater in the open

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Results: plant height is greater in the open

Results: there is no difference in germination between microsites

Results: no difference between microsites for days to 50% germination

Implications: competition may prevent establishment on cushions

Although density is higher in the open there is no difference in germination between microsites

Implications: competition may prevent establishment on cushions

Environmental stress

Michalet et al. 2006; Brooker et al. 2008; He et al 2013; McIntire et al. 2013

Stre

ngt

h o

f fa

cilit

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Conclusions

Seeds from plants found primarily in the open germinate equally well in both microsites

These plants may be competitively excluded at another life stage

Thank you!

Ron Long

Christopher Lortie

Rick Bello

R2= 0.224

R2= 0.021

Purpose: some previous studies had conflicting results

shrub open