Amelia Lamb

1s t Progress Report

March 19 th 2013

Shrub and understory annual plant effects on resident kangaroo rat species in a desert annual community

Introduction

Facilitation in plant communities

MacIntire and Fajardo 2014; Pugnaire et al. 2011; Soliveres et al. 2011; Holmgren and Scheffer 2010; Brooker et al. 2008; Bruno et al. 2003; Holmgren et al. 1997; Callaway and Walker 1997; Pugnaire et al. 1996.

Introduction

The Stress Gradient Hypothesis (SGH)

Michelet et al. 2013; Holmgren 2010; Malkinson 2010; Maestre et al. 2009; Brooker et al. 2008; Kawai et al. 2007; Lortie and Callaway 2006; Maestre et al. 2006; Callaway and Walker 1994.

Introduction

Armas and Pugnaire 2005; Gomez-Aparicio et al. 2004; Flores and Jurado 2003; Holzapfel 1999; Pugnaire et al . 1996; Callaway 1995.

Nurse Plants

Introduction

Systematic Review

•Purpose: summarize literature to identify extensively studied areas/research gaps

•Criteria: papers testing positive interactions/animal side of interaction

•Search: Web of knowledge (shrub*+animal*)• 844 articles

• 122 articles retained

•Data: direct/indirect; nature of interaction; reciprocal interactions; study species; climate; GPS

Chapter 1

Chapter 1Geographic Distribution of Previous Studies

Study Site and Species

Study Site and Species

Study Site and Species

Survey• Purpose: examine

the impact of shrubs and annuals on animal activity along a gradient• 5-point gradient-

sites differ by 200 meters• Microsites- shrub

vs. open• Replicates- 100

pairs/sub-site• Treatments-

annuals removed (50 pairs) annuals intact (50 pairs)

Chapter 2

Kelbaker Rd.

Chapter 2

Activity Measurements -burrows -scat -tracks -trails -total disturbance

Shrub/Annual Measurements -shrub dimensions -annual abundance -annual diversity -percent cover

Environmental Measurements -elevation -temperature -humidity

Survey

Chapter 2

Open Shrub0.00

0.10

0.20

0.30

0.40

Microsite

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Kangaroo rat foraging patterns and GUD

Chapter 3

• Purpose: examine the impact of shrubs and annuals on foraging patterns and GUD• 5-point gradient: sites differ by 200 meters•Microsites: shrub vs. open• # of Trials: 10-15• Replicates: 3/treatment/sub-site (60 trays)• Treatments: annuals removed; annuals intact

Kelbaker Rd.

Methods

• Trays: reinforced aluminum foil; sifted sand; millet seed

• Shrub side: positioned under north side near base and adjacent open area

• Set up: before sunset; flatten surface; set up cameras; collect trays/cameras before sunrise; record activity; sieve contents; weigh remaining seeds

• Pilot study: krats ate seeds; cameras recorded krat activity.

Chapter 3

Current Objectives• Lab• Finish extracting systematic review data• Begin writing review• Finish analyzing data from pilot survey and GUD trials

• Field (April 15th – May 30th)• Extensive survey of Larrea tridentata and associated annual

vegetation and animal activity (at least 100 paired shrub/open site per elevational sub-site)• 10-15 GUD trials; 4 treatments; 3 replicates per treatment in each

elevational sub-site (60 trays/trial)

Thank You!