Reflectance and image characteristics of selected noxious rangeland species


Everitt, J.H.; Escobar, D.E.; Davis, M.R.

Journal of Range Management 54(2): A106-A120

2001


This paper demonstrates the use of field reflectance measurements and aerial photography (colour-infrared and conventional colour) for distinguishing noxious plant species on rangelands. The visible/near-infrared (0.45-0.90 micro m) reflectance characteristics of several brush and weed species found on rangelands in the USA and Mexico are presented. The phenological stage of plants has an important influence on their spectral characteristics and subsequent detection on aerial photographs. Canopy architecture, vegetative density, and leaf pubescence are also important for distinguishing some species. Reflectance measurements are related to the plant species colour tonal responses on CIR and CC photographs. Plant species addressed include silverleaf sunflower (Helianthus argophyllus), broom snakeweed (Gutierrezia sarothrae), huisache (Acacia smallii [Acacia farnesiana]), Big Bend locoweed (Astragalus mollissimus var. earlei), Wooton locoweed (Astragalus wootonii), and Chinese tamarisk (Tamarix chinensis).

J.
Range
Manage.
54:
208
March
2001
Reflectance
and
image
characteristics
of
selected
noxious
range-
land
species
J.
H.
EVERITT,
D.
E.
ESCOBAR,
AND
M.
R.
DAVIS
Authors
are
range
scientist,
remote
sensing
specialist,
and
pilot,
USDA-ARS,
2413
E.
Highway
83,
Weslaco,
Tex.
78596.
The
authors
thank
Mario
Alaniz
for
his
assistance
in
obtaining
field
reflectance
measurements
and
preparation
of
illustrations,
and
Jeanne
Everitt
for
her
help
in
word
processing.
Key
Words:
remote
sensing,
color-infrared
photography,
conventional
color
photography,
noxious
brush
and
weeds
http://uvalde.tamu.edu/jrm/remote/boise.htm
Abstract
This
paper
demonstrates
the
use
of
field
reflectance
measurements
and
aerial
photography
(color-infrared
and
conventional
color)
for
distin-
guishing
noxious
plant
species
on
rangelands.
The
visible/near-infrared
(0.45-0.90
µm)
reflectance
characteristics
of
several
brush
and
weed
species
found
on
rangelands
in
the
U.S.
and
Mexico
are
presented.
The
phenological
stage
of
plants
has
an
important
influence
on
their
spec-
tral
characteristics
and
subsequent
detection
on
aerial
photographs.
Canopy
architecture,
vegetative
density,
and
leaf
pubescence
are
also
important
for
distinguishing
some
species.
Reflectance
measurements
are
related
to
the
plant
species
color
tonal
responses
on
CIR
and
CC
photographs.
Plant
species
addressed
include
silverleaf
sunflower
(Helianthus
argophyllus
Torr.
and
Gray),
broom
snakeweed
[Gutierrezia
sarothrae
(Pursh.)
Britt.
and
Rusby],
huisache
[Acacia
smallii
(L.)
Big
Bend
locoweed
[Astragalus
mollissimus
var.
earlei
(Rydb.)
Tidestr.],
Wooton
locoweed
(Astragalus
wootonii
Sheld.),
and
Chinese
tamarisk
(Tamarix
chinensis
Lour.).
Resumen
Este
documento
demuestra
el
use
de
las
medidas
de
reflexion
de
campo
y
de
la
fotographia
aerea
[color-infarrojo
(CIR)
y
color
conven-
cional
(CC)]
para
distinguir
especies
de
plantas
nocivas
en
los
pastizales.
Se
presentan
las
caracteristicas
de
reflexion
visibles
(poximas
a
infrarrojo,
0.45-0.90
m
m)
de
varias
especies
de
arbustos
y
maleza
encontrados
en
los
pastizales
en
E.U.
y
Mexico.
La
etapa
fenologica
de
las
plantas
tiene
una
influencia
importante
sobre
sus
caracteristicas
espectrales
y
su
deteccion
subsecuente
mediante
la
fotograffa
aerea.
La
arqui-
tectura
del
dosel
de
plantas,
la
densidad
de
la
vegetacion
y
el
desarrollo
de
la
hoja,
son
tambien
factores
importantes
para
distinguir
algunas
especies.
El
tono
del
color,
de
algunas
especies
de
plantas
presentadas
en
la
fotograffa
CIR
y
CC,
estan
relacionadas
con
las
medias
de
reflex-
ion.
Las
especies
de
plantas
citadas
incluyen:
girasol
silvestre
(Helianthus
argophluss
Torr.
y
Gray);
escobilla
de
bruja
[Gutierrezia
sarothrae
(Pursh.)
Britt.
Y
Rusby];
huisache
[Acacia
smallii
(L.)
Willd];
Big
Bend
locoweed
[Astragalus
mollissimus
var.
earlei
(Rydb.)
Tidestr.];
Wooton
locoweed
(Astragalus
wootonii
Sheld.);
y
tamarisk
chino
(Tamarix
chinesis
Lour.).
208
JOURNAL
OF
RANGE
MANAGEMENT
54(2),
March
2001