Large and Fine Scale Resiliency: Alder Disease in Alaska

Lori Trummer, USFSChrista Mulder, UAFBarbara Roy, U of OregonRoger Ruess, UAFGerald Adams, MSUGlen Stanosz, U of WisconsinLori Winton, USDA

Jennifer Rohrs-Richey

Alders (Alnus spp.)

Alnus crispa (uplands)

Alnus tenuifolia (floodplain)

Comments About Alders

“Are alders weeds?”

“Nobody really cares about alders in DNP. There are so many other cool things to study here.”

“I hate alders!”

Forest Service Investigating Dying AldersWed, April 29, 2009 

Posted in Alaska News

For the past few years the U-S Forest Service has been investigating the cause of a massive die off of Alders across much of Alaska stretching from Nome down to Skagway.Mike Mason, KDLG - Dillingham

Download Audio (MP3)

Alaska Public Radio Network (APRN)

SoilNitrogenBank

N

Why are alders essential to ecosystem health?

N-fixing bacteria

N2

Dieback and Mortality

Chena River

Canker Fungi: Cytospora canker (Valsa melanodiscus)

Natural Injuries for Pathogen Entry

River Ice Hare Browsing

RubbingSnow Loading

Colonization of Stem

Resilience on the Landscape

Fine scale resilience: Host control, physiology

Resiliency: Large vs. fine scale

Large scale resilience: Location on the landscape (siltbar, stand density, age)

Ecosystem resilience requires both large and fine scales

Physiological Damage to Alder

Local symptom with systemic affects

Pink– healthy tissue

Tan– dead tissue

Canker blocks water and nutrient transport

H2O

CO2

H2O

CO2

Leaf Surface: Strategy for Coping with Stress

OpenClosing

Optimum: conserve water AND maintain positive carbon balance

Can we influence resilience at both of these levels?

Can we reduce vulnerability (stresses)?

Degrading Resilience on the Landscape

Less destructive clearing practices

Reducing Vulnerability to Disease

Human perception of alders works against maintaining resilience

How to bring the social and ecological dynamics into conversation?

Research Support

National Institute for Global Environmental Change

U.S. Forest Service

Alder Physiology

2003 20041930 2005

Photo credit:Lori Trummer

BeginMonitoring

Cytospora canker isolated

Valsa alnichecklists

Timeline

2007

Forest Health Report

Experimental Inoculations

2006

Generating working hypotheses about disease

Quantifying Fine-Scale Resilience

Research Results:

Water Loss

Pho

tosy

nthe

is

(Car

bon

Upt

ake)

Agenda

Canker disease

Fine-scale resilience in alders

Disease on the landscape (Interior)

Alders in Alaska