IPM

Question 1

Invasive Species Defn

Answer 1

1. non native to the ecosystem
2. intro causes (or is likely to cause) economic or environmental harm or harm to human health

*1 of top 5 threats to biodiversity
*primarily human caused

Question 2

Ecological impacts of Invasives

Answer 2

increased water use reduces availability to desired plants

adverse effects on soil chemistry

reduced biodiversity

Question 3

Economic impacts of Invasives

Answer 3

reduced carrying capacity (livestock)

toxic to animals

costly to manage/remove

Question 4

3 phases of invasion process:

Answer 4

1. arrival and establishment (introduced and survives)
2. spread (population growth)
3. Equilibrium and Effects (becomes part of ecosystem with impacts to community)

Question 5

3 Levels of Control of Invasives

Answer 5

1. Prevention (public education, mgmt)
2. Eradication (early detection, eradication if possible)
3. Control (decrease impact to manageable level)

Question 6

MT Noxious Weeds list (inverted triangle)

Answer 6

High priority/prevention

Class 1A
1B
2A
2B (abundant in MT)
3

Low priority/control (abundant)

Question 7

4 attributes of successful weed mgmt:

Answer 7

1. get beyond symptoms to root cause (minimize repeat efforts)
2. no one answer (bio, chem, fire, mechanical)
3. clearly defined goals (driven by bio/eco/socio)
4. multi level approach

Question 8

Chemical Weed Mgmt includes:

Answer 8

pesticides (any chemical used to control living substance) including: insecticide, rodenticide, fungicide, herbicide

Question 9

Principle Uses of Herbicide are…

Answer 9

1. must contact plant when susceptible
2. remain long enough to be absorbed
3. reach living cellular site at a concentration significant enough to disrupt vital process/structures

Question 10

Herbicide mode of actions are:

Answer 10

1. growth regulating
2. amino acid synthesis inhibiting
3. photosynthesis inhibiting

Question 11

Herbicide Pros are:

Answer 11

less expensive than resource heavy approach

terrain has less impact

selective control

good for releasing in situ desirable plants

low labor

Question 12

Herbicide Cons are:

Answer 12

may kill non-target plants

may increase plant toxicity

social concerns

danger to applicator/environment

health hazards

Question 13

Where does herbicide go?

Answer 13

microbial decomp
chemical decomp
leaching
absorbed by clay/organic matter
run off
plant uptake
volatilization (air)

Question 14

Mechanical Weed Managment is…

Answer 14

physically removing unwanted species (cutting/pulling) by use of a tool to remove or destroy plant material

2 types:
Top Removal and Complete Removal

*often used with other treatments

Question 15

Pros of mechanical mgmt…

Answer 15

can target specific species/plants

no chemical side effects

Question 16

Cons of mechanical mgmt…

Answer 16

expensive
specialized equipment
may not kill the plant
high disturbance

Question 17

Biological Weed Management has 2 approaches:

Answer 17

1. Classical
2. targeted grazing

*key principle of both is selective herbivory

Question 18

Classical Bio Mgmt

Answer 18

using natural enemies of weeds including insects, pathogens (bacteria and fungi) to control infestation

can take ~11 years
goal is to REDUCE invasives

Question 19

Biocontrol Agents must be:

Answer 19

1. destructive to noxious plant
2. specific to host, harmless to others
3. able to survive and reproduce in new environment

Question 20

How do biocontrol agents act:

Answer 20

eat/destroy plant directly

create favorable conditions for infection by pathogen

change competitive relationships in community (seed eaters –> reduce seed set –> reduce competitive abilities)

Question 21

Steps to deploy biocontrol agent:

Answer 21

1. know the weed (home and invasive)
2. determine host specificity (MANY trials)
3. quarantine testing (choice or no choice)
4. field testing
5. mass rearing/release
6. monitor!

Question 22

Why not have goal to eradicate all invasive species?

Answer 22

There are multiple resource objectives and eradication would be costly and time consuming and diver resources from other needed objectives. Could also unintentionally create a niche for the invasive to come back (expensive cycle). You might also destroy unintended plants.