An Assessment and Management Protocol for

Arundo donax in the Salinas Valley Watershed

by Alana J. OakinsMay 2001

What is Arundo?

• invasive non-native species

• introduced in the 1800’s• rated 1 of 5 top species

of concern by CALEPPC• many associated

environmental problems

Why Should We Care?• out-competes

native vegetation• inability to

provide habitat and food for native species

• negatively affects stream flow and morphology

• water intensive

What can we do?

• federal, state and local “weed” laws (e.g. Clinton’s Executive Order and SB1740 & AB1168)

• economic and ethical implications to different stakeholders like landowners, agricultural community, and nurseries

• research (e.g. mapping studies)

Study Objectives

• to assess the feasibility of mapping Arundo using remote sensing

• to offer a policy recommendation for Monterey County

Assessing Arundo using Remote Sensing

• Why map Arundo?-it’s the first step-locating made easier-assess quantity-assess invasiveness-gives future direction

• Therefore…Can Arundo be differentiated from similar vegetation?

Study Site • near Gonzales, CA

Methods• Acquired imagery…Color-IR• Groundtruthed the image • Created training classes • Trained computer in TnTmips

(MicroImages, 1999) • Supervised classification

ResultsTraining Class Statistics

35

50

65

80

95

110

125

140

Infrared Red Green

Band

Mea

n Arundo

Willow

-Arundo is significantly different than similar vegetation

• Mapped Arundo with an accuracy of 95%

LegendGreen-ArundoRed-WillowPink-CottonwoodPurple-OakYellow-Grasses and ShrubsWhite-Bare GroundDark Blue-Water (deep)Light Blue-Water (shallow)*Black polygons-groundtruth data and training classes

Discussion• use a Color-IR • nominal pixel size of 2 m• supervised classification• red and green light

reflectance bands

A proposed policy…

• Arundo be included in the Monterey County Weed Management Plan

• funds be allocated for further Arundo research (e.g. mapping entire infestation)

An Effective policy...• completely understand why

Arundo even exists in Monterey County

• look to successful management examples as a guide

• public and private collaboration

Acknowledgements• Scott Hennessy• The Watershed Institute• Dr. Lars Pierce• Dr. David Takacs• Lee Johnson• Bruce Delgado