National Wetlands Research Center

National Wetlands Research Center

Marsh Dieback Syndrome (MaDS) Signature Key


Marsh Dieback Syndrome (MaDS) Signature KeyThe objective of this signature key is to provide a consistent method for photointerpreters to delineate important features of healthy and affected marsh. This key will assist the user in understanding marsh classification using high-altitude color infrared photography as applied to the Marsh Dieback Syndrome.

The process of developing a key iterates between field observations and laboratory analysis of the photography. Ground level field observations were carried-out primarily during the winter of 2001 with additional observations made at other times. Ongoing oblique, low-altitude monthly aerial observations have been conducted continuously since the summer of 2000. Whenever possible, the photos in this signature key refer to the same dates and locations in order to provide consistency across the scale of photography.


Impacted by Brown Marsh:

IEM

BM2

USBM

USDM

IUS

IOW

IAB

Non-impacted Areas:

US

OW

AB

EM

SS

FO

RS

UplandUB

UR

USS

UF

UU

Modifiers:x

s

h

o

k

SS3 SS4 SSgSS1

FO1 FO3 FO4

USS3 USS4USS1

UF3 UF4UF1

Wetland

Marsh Dieback Syndrome (MaDS) Signature Key

BACK TO INTRODUCTION


Non-Impacted

Wetland Wetlands are saturated or inundated by water for anextended period of time during the growing season. For thephotointerpretation process, the hydroregime results in hydric soilformation and hydrophytic plant species that present consistentaerial photographic signatures.

Upland For photointerpretation purposes, uplands are areas notperiodically saturated or inundated, resulting in non-hydrophyticvegetation and soil signatures.

BACK

Impacted

In the photointerpretation process, MaDS areas are detected fromchanges in 1998 and 2000 aerial color infrared photography. Thesaltmarsh should be dominated by smooth cordgrass (Spartinaalternifolia). Due to MaDS, the marsh may be completely orpartially denuded of that species revealing unaffected species,exposed soil or water.

National Wetlands Research Center BACK

Classification Modifiers

All modifiers are lowercase letters. These are labels that may be appended to some of thecategories to expand or add precision. For example, an upland barren (UB) that is a spoilarea (s) may be designated “UBs”.

x Excavateds Spoilh Impoundedg Mangroveo Oilk Artificial

National Wetlands Research Center BACK

EM example (Aerial Photography)

EM example (Oblique Photo)

EM example (Ground Photo)

EM Emergent Marsh

EM Healthy emergent marsh is composed of relatively dense vegetationdominated by smooth cordgrass (Spartina alterniflora). Other emergent marsh speciesthat may be present, usually to a considerably lesser extent, include saltgrass (Distichlisspicata),needle rush (Juncus romerianus), and roseau cane (Phragmites australis). Thereare several other herbaceous species that may occur in the salt marsh but they do notcontribute a significantly to the photographic signature. The emergent vegetation isusually 0.3 to 1.5 m tall. Aerial photography signature for S. alterniflora is typicallybrilliant fuchsia with an even texture.

BACKNational Wetlands Research Center

EM_CIR

BACK

EM_OBL

BACK

EM_GRD

BACK

SS Scrub/shrub is composed of woody vegetation under 6 meters in height.Common shrub/scrub species include mangrove (Avicennia germinans), toothache tree(Zanthoxylum clava-herculis), sugarberry (Celtis laevagata), wax myrtle (Myricacerifera), saltbush (Baccharis halimifolia), yaupon (Ilex vomitoria), and marsh elder (Ivafrutescens), live oak (Quercus virginiana). There are four subclasses of shrub/scrubincluding:

Deciduous 1 Uneven texture, color is variable butgenerally a pale pink.

Evergreen 3 Uneven texture, color is variable butgenerally dark red.

Mixed (decid/ever) 4 Uneven texture with highly variable colorMangrove g Uneven to smooth texture with consistent

brilliant red.SS1 example (Aerial Photography)

SS1 example (Oblique Photo)

SSg example (Aerial Photography)

SSg example (Oblique Photo)

SSg example (Ground Photo)

SS Scrub Shrub


SS1_CIR

BACK

SS1_OBL

BACK

SSg_CIR

BACK

SSg_OBL

BACK

SSg_GRD

BACK

FO1 example (Aerial Photography)

FO1 example (Oblique Photo)

FO1 example (Ground Photo)

FO Forest

FO Forest cover is composed of roughly the same species as shrub/scrub butthe canopy is greater than 6 meters in height. Subclasses include:



Mixed (decid/ever) 4 Uneven texture with highly variable color


FO1_CIR

BACK

FO1_OBL

BACK

FO1_GRD

BACK

AB Aquatic Bed

AB Aquatic bed is composed of algae, floating aquatic, rooted submergedaquatic vegetation. Smooth, smokey texture with variable color from dark purples tolavender.


OW example (Oblique Photo)

OW example (Ground Photo)

OWx example (Oblique Photo)

OW Open Water

OW Open water is a vegetation-free water signature that is consistent with1998 photography as being open water to differentiate it from recent formation due tomarsh dieback. Even texture and dark blue.


OW_OBL

BACK

OW_GRD

BACK

OWx_OBL

BACK

US example (Oblique Photo)

US example (Ground Photo)

US Unconsolidated Shore

BACK

US Unconsolidated shore is exposed vegetation-free soil, sand or exposed shell bedthat is saturated or tidally inundated. The 2000 photography is checked for consistencywith 1998 photography to differentiate it from recent formation due to MaDS. Eventexture and grey to bluish depending upon moisture presence. Lack of moisture results inan even white color.


US_OBL

BACK

US_GRD

BACK

RSk example (Ground Photo)

RS Rocky Shore

BACK

RS Rocky shore is rip-rap deposited as oil canal plugs, shore stabilizationstructures and other similar features. Smooth texture, brilliant white.


RSk_GRD

BACK

USS1 example (Ground Photo)

USS Upland Scrub Shrub

BACK

USS Upland shrub/scrub may be composed of a large list of plants includingthe previously listed wetland shrub/scrub species.





USS1_GRD

BACK

UF1 example (Aerial Photography)

UF1 example (Oblique Photo)

UF1 example (Ground Photo)

UF Upland Forest

BACK

UF Upland forest, like upland shrub/scrub may be composed of a large list of plant species. The canopyis greater than 6 meters in height.





UF1_CIR

BACK

UF1_OBL

BACK

UF1_GRD

BACK

UR example (Aerial Photography)

UR example (Ground Photo)

UR Upland Range

BACK

UR Upland range is mown grassland or pastures. Texture is smooth with evenlight red color. No dark mottling present which would indicate saturated soils.


UR_CIR

BACK

UR_GRD

BACK

UB example (Aerial Photography)

UB example (Oblique Photo)

UB Upland Barren

BACK

UB Recently deposited or bulldozed areas. Textured like oatmeal. Color iswhitish-grey.


UB_CIR

BACK

UB_OBL

BACK

UU example (Aerial Photography)

UU example (Ground Photo)

UUo example (Aerial Photography)

UU Upland Urban

BACK

UU Developed upland areas containing houses, buildings or other structures.


UU_CIR

BACK

UU_GRD

BACK

UUo_CIR

BACK

IEM example (Aerial Photography)

IEM example (Oblique Photo)

IEM example (Ground Photo)

IEM Slightly impacted emergent marsh vegetation.

BACK

IEM Slightly impacted emergent marsh vegetation. Herbaceous plants exhibitsome color characteristics similar to healthy marsh vegetation but are less brilliant to palepink with even texture. No soil exposure is present within this signature.


IEM_CIR

BACK

IEM_OBL

BACK

IEM_GRD

BACK

BM2 example (Aerial Photography)

BM2 example (Oblique Photo)

BM2 example (Ground Photo)

BM2 Moderately impacted emergent marsh with intact vegetation signature.

BACK

BM2 Moderately impacted emergent marsh with intact vegetation signature.Faint pink present with pale, gray-blue to whitish inclusions. Texture is still smoothwithout soil exposure.


BM2_CIR

BACK

BM2 _OBL

BACK

BM2 _GRD

BACK

USBM example (Aerial Photography)

USBM example (Oblique Photo)

USBM example (Ground Photo)

USBM Unconsolidated shore/severely impacted emergent marsh.

BACK

USBM Unconsolidated shore/severely impacted emergent marsh.Vegetation less dense with some soil exposed. Color is quite variable. The substratecolor (faintly pale bluish to clear blue) is becoming increasingly evident through the palepink to white vegetation. Texture is clumped white to pink inclusions on the bluishbackground.


USBM_CIR

BACK

USBM_OBL

BACK

USBM_GRD

BACK

USDM example (Aerial Photography)

USDM example (Oblique Photo)

USDM example (Ground Photo)

USDM Unconsolidated shore/dead emergent marsh.

BACK

USDM Unconsolidated shore/dead emergent marsh. Stubble present withexposed soil as dominant signature. Color is gray to bluish-gray with no apparentphotosynthetic tissue. There is no pink component whatsoever. Texture is very smooth,even. Color transitions are smooth and gradual.


USDM_CIR

BACK

USDM_OBL

BACK

USDM_GRD

BACK

IUS example (Aerial Photography)

IUS example (Oblique Photo)

IUS example (Ground Photo)

IUS Impacted, unconsolidated shore.

BACK

IUS Impacted, unconsolidated shore. Exposed soil with no vegetation present.Color is dark blue with absolutely no reddish or pinkish component. Very little or nowhite or gray indicating stubble is not present. Differentiated from non-impactedunconsolidated shore by use of historical (1998 or earlier) photography.


IUS_CIR

BACK

IUS_OBL

BACK

IUS_GRD

BACK

IOW Impacted open water.


IOW Impacted open water. These areas were marsh prior to the advent of theMaDS. These are the most degraded areas with elevation loss (through erosion and/orsubsidence) allowing the formation of permanent ponds within the marsh or confluencewith pre-existing open water. Signature is differentiated from non-impacted open waterby use of historical (1998 or earlier) photography.

IAB example (Ground Photo)

IAB Impacted aquatic bed.


IAB Impacted aquatic bed. MaDS areas that have converted to aquatic vegetation.

Signature differentiated from unimpacted aquatic vegetation by use of historical (1998 orearlier) photography.

IAB_GRD

BACK

National Wetlands Research Center

Documents

Transcript of National Wetlands Research Center