Invasive plants What are they

1

• Invasive plants What are they?
• b) Ecological definitions and characterizations

Nevadas Coordinated Invasive Weed Strategy
(http//agri.nv.gov/nwac/weedplan_p.htm)
2

• Invasive plants What are they?
• b) Ecological definitions and characterizations

• Nevadas Coordinated Invasive Weed Strategy
• Prepared by Nevada Weed Action Committee (NV
  Dept. Ag)
• Included local, state, and federal
  agencies/governments NCE private sector

3

• Invasive plants What are they?
• b) Ecological definitions and characterizations

• Nevadas Coordinated Invasive Weed Strategy
• Nevada Weed Action Committee
• Uses USDA definition of noxious weeds species
  of plants that cause disease or are injurious to
  crops, livestock or land, and thus are
  detrimental to agriculture, commerce or public
  health

4

• Invasive plants What are they?
• b) Ecological definitions and characterizations

• Nevadas Coordinated Invasive Weed Strategy
• Nevada Weed Action Committee
• Noxious weed definition
• Invasive weeds often share characteristics such
  as
• Highly competitive Cause environmental
  degradation
• Exotic Easily spread
• Highly aggressive Are difficult to control
• Cause economic loss Augment wildfires

5

• Invasive plants What are they?
• b) Ecological definitions and characterizations

• Nevadas Coordinated Invasive Weed Strategy
• Nevada Weed Action Committee
• Noxious weed definition
• Invasive weed characteristics
• Species of concern
• Species that have potential to cause greatest
  impact on Nevadas ecosystem and economic well
  being
• Not all are on noxious weed list
• Includes
• Red brome Cheatgrass
• Whitetops Knapweeds
• Yellow starthistle Thistles
• Rush skeletonweed Medusahead
• Saltcedar Watermilfoil

6

• Invasive plants What are they?
• b) Ecological definitions and characterizations

• NV Coordinated Invasive Weed Strategy
• The Nature Conservancy (http//tncweeds.ucdavis.ed
  u/common.html)
• Invasive species are
• Spread from human settings into wild
• Once wild, continue to reproduce
• Displace native species reduces biodiversity
• Usually non-native

7

• Invasive plants What are they?
• b) Ecological definitions and characterizations

• NV Coordinated Invasive Weed Strategy Nature
  Conservancy
• Davis Thompson (2000)
• Ecologists have used different words for invasive
  species
• Alien Exotic
• Invasive Non-indigenous
• Imported Weedy
• Introduced Non-native
• Immigrant Colonizer
• Naturalized

8

• Invasive plants What are they?
• b) Ecological definitions and characterizations

• NV Coordinated Invasive Weed Strategy Nature
  Conservancy
• Davis Thompson (2000)
• Ecologists have used different words for invasive
  species
• Nomenclature based on 3 major colonization
  concepts
• Dispersal Short Long

9

• Invasive plants What are they?
• b) Ecological definitions and characterizations

10

• Invasive plants What are they?
• b) Ecological definitions and characterizations

11

• Invasive plants What are they?
• b) Ecological definitions and characterizations

12

• Invasive plants What are they?
• b) Ecological definitions and characterizations

13

• Invasive plants What are they?
• b) Ecological definitions and characterizations

14

• Invasive plants What are they?
• b) Ecological definitions and characterizations

15

• Invasive plants What are they?
• b) Ecological definitions and characterizations

16

• Invasive plants What are they?
• b) Ecological definitions and characterizations

• NV Coordinated Invasive Weed Strategy Nature
  Conservancy
• Davis Thompson (2000)
• Richardson et al. (2000)
• Processes and barriers

17

• Invasive plants What are they?
• b) Ecological definitions and characterizations

NV Coordinated Invasive Weed Strategy Nature
Conservancy Davis Thompson (2000) Richardson
et al. (2000) Process Introduction
Introduced area
Home range
18

• Invasive plants What are they?
• b) Ecological definitions and characterizations

NV Coordinated Invasive Weed Strategy Nature
Conservancy Davis Thompson (2000) Richardson
et al. (2000) Process Barrier Introduction G
eographic
Introduced area
Geographic
Home range
19

• Invasive plants What are they?
• b) Ecological definitions and characterizations

NV Coordinated Invasive Weed Strategy Nature
Conservancy Davis Thompson (2000) Richardson
et al. (2000) Process Barrier If
successful Introduction Geographic Alien
Introduced area
Geographic
Home range
20

• Invasive plants What are they?
• b) Ecological definitions and characterizations

NV Coordinated Invasive Weed Strategy Nature
Conservancy Davis Thompson (2000) Richardson
et al. (2000) Process Barrier If
successful Introduction Geographic Alien Natur
alization Environmental Casual
Introduced area
Geographic
Environment
Home range
21

• Invasive plants What are they?
• b) Ecological definitions and characterizations

NV Coordinated Invasive Weed Strategy Nature
Conservancy Davis Thompson (2000) Richardson
et al. (2000) Process Barrier If
successful Introduction Geographic Alien Natur
alization Environmental Casual Reproductive
Naturalized
Introduced area
Geographic
Reproduce
Environment
Home range
22

• Invasive plants What are they?
• b) Ecological definitions and characterizations

NV Coordinated Invasive Weed Strategy Nature
Conservancy Davis Thompson (2000) Richardson
et al. (2000) Process Barrier If
successful Introduction Geographic Alien Natur
alization Environmental Casual Reproductive
Naturalized Invasion Dispersal Invasive
Introduced area
Geographic
Reproduce
Environment
Home range
Disperse
Natural area
Disturbed area
23

• Invasive plants What are they?
• b) Ecological definitions and characterizations

• NV Coordinated Invasive Weed Strategy Nature
  Conservancy
• Davis Thompson (2000)
• Richardson et al. (2000)
• Processes and barriers
• Definitions
• Alien plants plant taxa in a given area whose
  presence is due to intentional or accidental
  introduction as a result of human activity

24

• Invasive plants What are they?
• b) Ecological definitions and characterizations

• NV Coordinated Invasive Weed Strategy Nature
  Conservancy
• Davis Thompson (2000)
• Richardson et al. (2000)
• Processes and barriers
• Definitions
• Alien plants plant taxa in a given area whose
  presence is due to intentional or accidental
  introduction as a result of human activity
• How determine?
• Disjunct geographic range (Richardson et al.)
• typically gt100 km or past a known geographic
  barrier

25

• Invasive plants What are they?
• b) Ecological definitions and characterizations

• NV Coordinated Invasive Weed Strategy Nature
  Conservancy
• Davis Thompson (2000)
• Richardson et al. (2000)
• Processes and barriers
• Definitions
• Alien plants plant taxa in a given area whose
  presence is due to intentional or accidental
  introduction as a result of human activity
• How determine?
• Disjunct geographic range (Richardson et al.)
• 9 types of evidence (Schwartz in Luken Thieret
  1997)
• Fossil evidence

26

• Invasive plants What are they?
• b) Ecological definitions and characterizations

• NV Coordinated Invasive Weed Strategy Nature
  Conservancy
• Davis Thompson (2000)
• Richardson et al. (2000)
• Processes and barriers
• Definitions
• Alien plants plant taxa in a given area whose
  presence is due to intentional or accidental
  introduction as a result of human activity
• How determine?
• Disjunct geographic range (Richardson et al.)
• 9 types of evidence (Schwartz in Luken Thieret
  1997)
• Fossil evidence
• Historical evidence

27

• Invasive plants What are they?
• b) Ecological definitions and characterizations

• NV Coordinated Invasive Weed Strategy Nature
  Conservancy
• Davis Thompson (2000)
• Richardson et al. (2000)
• Processes and barriers
• Definitions
• Alien plants plant taxa in a given area whose
  presence is due to intentional or accidental
  introduction as a result of human activity
• How determine?
• Disjunct geographic range (Richardson et al.)
• 9 types of evidence (Schwartz in Luken Thieret
  1997)
• Fossil evidence
• Historical evidence
• Habitat

28

• Invasive plants What are they?
• b) Ecological definitions and characterizations

• NV Coordinated Invasive Weed Strategy Nature
  Conservancy
• Davis Thompson (2000)
• Richardson et al. (2000)
• Processes and barriers
• Definitions
• Alien plants plant taxa in a given area whose
  presence is due to intentional or accidental
  introduction as a result of human activity
• How determine?
• Disjunct geographic range (Richardson et al.)
• 9 types of evidence (Schwartz in Luken Thieret
  1997)
• Fossil evidence
• Historical evidence
• Habitat
• Geographic distribution

29

• Invasive plants What are they?
• b) Ecological definitions and characterizations

• NV Coordinated Invasive Weed Strategy Nature
  Conservancy
• Davis Thompson (2000)
• Richardson et al. (2000)
• Processes and barriers
• Definitions
• Alien plants plant taxa in a given area whose
  presence is due to intentional or accidental
  introduction as a result of human activity
• How determine?
• Disjunct geographic range (Richardson et al.)
• 9 types of evidence (Schwartz in Luken Thieret
  1997)
• Fossil evidence
• Historical evidence
• Habitat
• Geographic distribution
• Frequency of naturalization

30

• Invasive plants What are they?
• b) Ecological definitions and characterizations

• NV Coordinated Invasive Weed Strategy Nature
  Conservancy
• Davis Thompson (2000)
• Richardson et al. (2000)
• Processes and barriers
• Definitions
• Alien plants plant taxa in a given area whose
  presence is due to intentional or accidental
  introduction as a result of human activity
• How determine?
• Disjunct geographic range (Richardson et al.)
• 9 types of evidence (Schwartz in Luken Thieret
  1997)
• Fossil evidence Genetic diversity
• Historical evidence
• Habitat
• Geographic distribution
• Frequency of naturalization

31

• Invasive plants What are they?
• b) Ecological definitions and characterizations

• NV Coordinated Invasive Weed Strategy Nature
  Conservancy
• Davis Thompson (2000)
• Richardson et al. (2000)
• Processes and barriers
• Definitions
• Alien plants plant taxa in a given area whose
  presence is due to intentional or accidental
  introduction as a result of human activity
• How determine?
• Disjunct geographic range (Richardson et al.)
• 9 types of evidence (Schwartz in Luken Thieret
  1997)
• Fossil evidence Genetic diversity
• Historical evidence Reproductive pattern
• Habitat
• Geographic distribution
• Frequency of naturalization

32

• Invasive plants What are they?
• b) Ecological definitions and characterizations

• NV Coordinated Invasive Weed Strategy Nature
  Conservancy
• Davis Thompson (2000)
• Richardson et al. (2000)
• Processes and barriers
• Definitions
• Alien plants plant taxa in a given area whose
  presence is due to intentional or accidental
  introduction as a result of human activity
• How determine?
• Disjunct geographic range (Richardson et al.)
• 9 types of evidence (Schwartz in Luken Thieret
  1997)
• Fossil evidence Genetic diversity
• Historical evidence Reproductive pattern
• Habitat Possible means of introduction
• Geographic distribution
• Frequency of naturalization

33

• Invasive plants What are they?
• b) Ecological definitions and characterizations

• NV Coordinated Invasive Weed Strategy Nature
  Conservancy
• Davis Thompson (2000)
• Richardson et al. (2000)
• Processes and barriers
• Definitions
• Alien plants plant taxa in a given area whose
  presence is due to intentional or accidental
  introduction as a result of human activity
• How determine?
• Disjunct geographic range (Richardson et al.)
• 9 types of evidence (Schwartz in Luken Thieret
  1997)
• Fossil evidence Genetic diversity
• Historical evidence Reproductive pattern
• Habitat Possible means of introduction
• Geographic distribution Oligophagous insects
• Frequency of naturalization

34

• Invasive plants What are they?
• b) Ecological definitions and characterizations

• NV Coordinated Invasive Weed Strategy Nature
  Conservancy
• Davis Thompson (2000)
• Richardson et al. (2000)
• Processes and barriers
• Definitions
• Alien plants
• Casual alien plants alien plants that flourish
  (and even occasionally reproduce), but do not
  form self-replacing populations. Continued
  presence depends on re-introductions.

35

• Invasive plants What are they?
• b) Ecological definitions and characterizations

• NV Coordinated Invasive Weed Strategy Nature
  Conservancy
• Davis Thompson (2000)
• Richardson et al. (2000)
• Processes and barriers
• Definitions
• Alien plants
• Casual alien plants
• Naturalized plants alien plants that reproduce
  consistently and sustain populations over many
  life cycles without direct intervention by humans

36

• Invasive plants What are they?
• b) Ecological definitions and characterizations

• NV Coordinated Invasive Weed Strategy Nature
  Conservancy
• Davis Thompson (2000)
• Richardson et al. (2000)
• Processes and barriers
• Definitions
• Alien plants
• Casual alien plants
• Naturalized plants
• Invasive plants naturalized plants that produce
  reproductive offspring (often in large numbers)
  at considerable distance from parent plants
• gt100m lt50 years for seed dispersing species
• gt6 m gt3 years for vegetatively reproducing
  species

37

• Invasive plants What are they?
• b) Ecological definitions and characterizations

• NV Coordinated Invasive Weed Strategy Nature
  Conservancy
• Davis Thompson (2000)
• Richardson et al. (2000)
• Processes and barriers
• Definitions
• Alien plants
• Casual alien plants
• Naturalized plants
• Invasive plants

Increasing level of reproductive success
38

• Invasive plants What are they?
• b) Ecological definitions and characterizations

• NV Coordinated Invasive Weed Strategy Nature
  Conservancy
• Davis Thompson (2000)
• Richardson et al. (2000)
• Processes and barriers
• Definitions
• Alien plants
• Casual alien plants
• Naturalized plants
• Invasive plants
• Weeds plants that grow in sites where they are
  not wanted usually have economic or
  environmental effects

Increasing level of reproductive success
39

• Invasive plants What are they?
• b) Ecological definitions and characterizations

• NV Coordinated Invasive Weed Strategy Nature
  Conservancy
• Davis Thompson (2000)
• Richardson et al. (2000)
• Processes and barriers
• Definitions
• Alien plants
• Casual alien plants
• Naturalized plants
• Invasive plants
• Weeds
• Transformers subset of invasive plants that
  change ecosystems

Increasing level of reproductive success
40

• Invasive plants What are they?
• a) State and Federal laws and regulations
• Important from legal perspective
• b) Ecological definitions and characterizations
• Important for understanding the ecological
  processes and consequently, how to prevent and
  control invasions