Nurse-plant effects in arid environments and their possible usage as restoration tools

Alessandro Filazzola and Christopher LortieNovember 2013

Aral Sea

Aral Sea

Diversity of the Desert

Stress Gradient Hypothesis

Major theories examined

Malkinson & Tielbörger 2010

SGH extension to apply to disturbance◦ Biotic stress gradient

Nurse-plants can reduce disturbance ◦ Shared defences (thorns/branches)◦ Reduced palatability of neighbours◦ Associational resistance

Major theories examined

Indirect facilitation◦ Apparent competition◦ Mycorrhiza colonization◦ Seed trapping◦ Magnet species concept

Major theories examined

Molina‐Montenegro et al. 2008

Research Project

Abiotic stress amelioration

Substrate modification

Herbivore protection

Soil modificationPollinator visitation

Seed trapping

PLANT GROWTH

SEEDLINGREPRODUCTION

Nurse-mediated evolutionSEED

Nurse-mediated distribution

A conceptual framework summarizing nurse-plant mechanisms by protégé life-stage

Abiotic stress amelioration

Substrate modification

Herbivore protection

Soil modificationPollinator visitation

Seed trapping

PLANT GROWTH

SEEDLINGREPRODUCTION

Nurse-mediated evolutionSEED

Nurse-mediated distribution

A conceptual framework summarizing nurse-plant mechanisms by protégé life-stage

Nurse Mechanism

Seed Trapping

Substrate Modification

Abiotic Stress Amelioration

Herbivore Protection

Pollinator Visitation

Nurse-mediate distribution

Nurse-mediated evolution

Responding life-

stage

Seeds

Germination

Plant Growth

Reproduction

Mojave National Preserve

A – Effect of Larea spp. (+/-) on vegetation + seedbank by size + elevation (add sand disposition)B – Facilitated seed arrival of Larea spp. (+/-)C – Compare transient and persistent seedbank

2.1 313 m

2.2 515 m

2.3737 m

2.4951 m

2.51128 m

Gradient environmental measures

- Light- Temp- Moisture- Wind

Progress to date

Site 1.3North Facing

Site 1.2South Facing

Site 1.1Plateau

Panoche Hills

A – Effect of Ephedra spp. (+/-) on vegetation + seedbank by size + aspect (N,S,0)B – Facilitated seed arrival of Ephedra spp. (+/-)C – Pollinator facilitation by Ephedra spp. using pan-traps + Ipod Nanos (+/-). D – Ephedra spp. traits as a habitat for K. rats + L. lizards

Parking Lot

- Light- Temp- Moisture- Wind

Progress

Mammal/BirdExclusion

InsectExclusion

Control -No Exclusion

Control +Full Exclusion

Progress to date

Thank you!