The reason you would map weeds is so people can accurately identify and delineate land that has noxious weeds on it. In other words, to find weeds and evaluate their management control.

    There are many different ways you can map weeds. One is by taking pictures from helicopters, airplanes, and satellites. Another way is by using a GPS. The last way we will talk about is by having a base map and putting a hand map over the top and draw out the infested area. We will go over each of these, one at a time.

    The first way we described was by taking pictures from helicopters, airpalnes, and satellites. This works very well since you can actually point out the infestation and it is always there for proof. But, to do this, it takes a lot of time, pictures, and money. It is very effective, though.

    The second way was by using a GPS. This will tell you where you are down to the minutes, and seconds (depending on the quality of the unit). This way, you could easily see where you are, walk around the infestation and see how big it is and exactly where it is. You would think that this would be the best way to do it, but the GPS's cost close to $2500. Plus, they don't work through thick things such as: houses, buildings, cars, etc...

    The last and most commonly used way is by having a base map and putting a hand map over the top and the draw out the infested area. To do this, you just get a regular map of the area in which you would like to survey. Then you put a transparent sheet of paper over the top and this is your hand map. Once you have that, you use symbols and colors to coordinate with the various types of noxious weeds. For example: the area's symbol depends on its size: x = less than 0.1 of an acre, /\ (a triangle) = 0.1 to 1 acre, a box around the area = 1 tp 5 acres, actually outlining the area = larger than 5 acres, and lines = infestations that follow linear features such as roads and streams. There is also a five-letter code and color designations for the 15 different noxious weeds in Montana. They are as follows:
 

Noxious weed species common name	Scientific name	WSSA 5-letter code	1*Designated color	2*Designated Color
Category 1
leafy spurge	Euphorbia esula	EPHES	Green (739)	Peacock Green (739)
Canada thistle	Cirsium arvense	CIRAR	Tuscan Red (746 1/2)	Tuscan Red (746 1/2)
Russian knapweed	Centaurea repens	CENRE	Carmine Red (745)	Terra Cotta (745 1/2)
spotted knapweed	Centaurea maculosa	CENMA	Lavender (742 1/2)	Parma Violet (742 1/2)
diffuse knapweed	Centaurea diffusa	CENDI	Light Grey (734 1/2)	Warm Grey (734 1/2)
field bindweed	Convolvulus arvensis	CONAR	Pink (743)	Deco Pink (743)
whitetope (hoary cress)	Cardaria draba	CADDR	Sky Blue (740 1/2)	Peacock Blue (740 1/2)
Dalmation toadflax	Linaria dalmatica	LINDA	Canary Yellow (735)	Canary Yellow (735)
St. Johnswort (goatweed)	Hypericum perforatum	HYPPE	Olive Green (739 1/2)	Olive Green (739 1/2)
sulfur cinquefoil	Potentilla recta	PTLRC	Orange (737)	Orange (737)
Category 2
dyer's woad	Isatis tinctoria	ISATI	Grass Green (738)	Grass Green (738)
purple loosestrife	Lythrum salicaria	LYTSA	Purple (752)	Dahlia Purple (752)
purple loosestrife	Lythrum virgatum	LYTVI	Black (747)	Black (747)
Category 3
yellow starthistle	Centaurea solstitialis	CENSO	Ultramarine (740)	Ultramarine (740)
common crupina	Crupina vulgaris	CJNVU	Violet (742)	Violet (742)
rush skeletonweed	Chondrilla juncea	CHOJU	Scarlet Red (744)	Scarlet Red (744)

1* means that you use the old version of the Berol VERITHIN pencil pack. 2* means that you use the new version of the Berol VERITHIN pencil pack. The old version is in a white box. The new one is in a black box.

We got this table from Montana Noxious Weed Survey and Mapping System.

    When you are mapping there are standards you have to live up to:
1.  You have to outline the survey area on the map.
2.  Then you put the date you surveyed down in the upper right corner of the outlined area.
3.  Draw the appropriate intested acres symbol on the map, using correct color pencil.
4.  Write the WSSA code on the map using the correct color pencil.
5.   Record cover class on the map next to the infested area symbol.
6.   Last would be to fill out the Metadata form.

HOME

Welcome to Noxious Weed Survey and Mapping System
Invasive Weeds: A Growing Plan:
Noxious Weeds
Biology and Management of Noxious Rangeland Weeds
Preventing Weeds from Spreading
Management Direction
Mapping Process
Useful  Links
Noxious Weed Awareness
Weed and Pest Control