Source: California Invasive Plant Council


URL of this page: http://www.cal-ipc.org/site/paf/243
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Cal-IPC Plant Assessment Form

For use with "Criteria for Categorizing Invasive Non-Native Plants that Threaten Wildlands"
by the California Invasive Plant Council and the Southwest Vegetation Management Association

Table 1. Species and Evaluator Information

Species name
(Latin binomial):
The official Latin binomial name for this species. Specify only one name here. Additional species names may go into the Synonyms field.

Acacia melanoxylon

Synonyms:
Additional Latin binomial names for this species. Separate multiple names with a ; character. Please avoid narrative descriptions, and list only the binomial names.
Common names:
Common names for this species. Separate multiple names with a ; character.
blackwood acacia
Evaluation date:
The date(s) when this species PAF was filled out, modified, or reviewed. This is free-form text, so it may include multiple dates or other notes.
05/20/04 and 5/17/05
Evaluator #1 John J. Knapp/ Invasive Plant Program Manager
Catalina Island Conservancy
P.O. Box 2739 Avalon, CA 90704
(310) 510-1299
jknapp@catalinaconservancy.org
Evaluator #2 Elizabeth Brusati/Project Manager
California Invasive Plant Council
1442-A Walnut St. #462, Berkeley, CA 94709
(510) 843-3902
edbrusati@cal-ipc.org
List committee members: Jake Sigg, Peter Warner, Bob Case, John Knapp, Elizabeth Brusati
Committee review date: 7/8/05
List date:
Re-evaluation date(s):
General comments
on this assessment:
Enter any additional notes about this assessment, such as factors affecting the reliability or completeness of the answers, likely affects of impacts, or research which is not specific to California but is still relevant in the evaluation of this species.
Due to the lack of information on A. melanoxylon, a small portion of data from related Acacia species were used to complete this ranking, and were specified when used.

Table 2. Criteria, Section, and Overall Scores

Overall Score

Plant scoring matrix
Based on letter scores from Sections 1 through 3 below

ImpactInvasivenessDistribution
AA BAnyHighNo Alert
AC DAnyModerateAlert
BA BA BModerateNo Alert
BA BC DModerateAlert
BC DAnyLimitedNo Alert
CAA BModerateNo Alert
CAC DLimitedNo Alert
CBAModerateNo Alert
CBB DLimitedNo Alert
CCAnyLimitedNo Alert
DAnyAnyNot ListedNo Alert

Limited

Alert Status

Plant scoring matrix
Based on letter scores from Sections 1 through 3 below

ImpactInvasivenessDistributionAlert
AA or BC or DAlert
BA or BC or DAlert

No Alert

Documentation

The total documentation score is the average
of Documentation scores given in Table 2.

Reviewed Scientific Publication4 points
Other Published Material3 points
Observational2 points
Anecdotal1 points
Unknown or No Information0 points

2.8 out of 5

Score Documentation
1.1 Impact on abiotic ecosystem processes
Consider the impact on the natural range and variation of abiotic ecosystem processes and system-wide parameters in ways that significantly diminish the ability of native species to survive and reproduce. Alterations that determine the types of communities that can exist in a given area are of greatest concern. Examples of abiotic processes include:
- fire occurrence, frequency, and intensity;
- geomorphological changes such as erosion and sedimentation rates;
- hydrological regimes, including soil water table;
- nutrient and mineral dynamics, including salinity, alkalinity, and pH;
- light availability (e.g. when an aquatic invader covers an entire water body that would otherwise be open).

Select the one letter below that best describes this species’ most severe impact on an abiotic ecosystem process:
A. Severe, possibly irreversible, alteration or disruption of an ecosystem process.
B. Moderate alteration of an ecosystem process.
C. Minor alteration of an ecosystem process.
D. Negligible perceived impact on an ecosystem process.
U. Unknown.
C. Minor Reviewed Scientific Publication
Impact
Section 1 Scoring Matrix
Q 1.1Q 1.2Q 1.3Q 1.4Score
AAAnyAnyA
ABA,BAnyA
ABC,D,UAnyB
AC,D,UAnyAnyB
BAAAnyA
BABAA
BAB,CB-D,UB
BAC,D,UAA
BAC,D,UB-D,UB
BBAAA
BC,D,UAAB
BB-DAB-D,UB
BB-DB-D,UAnyB
BD,UC,D,UA-BB
BD,UC,D,UC,D,UC
C-D,UAAAnyA
CBAAnyB
CA,BB-D,UAnyB
CC,D,UAnyAnyC
DA,BBAnyB
DA,BC,D,UAnyC
DCAnyAnyC
DD,UAnyAnyD
UAB,CAnyB
UB,CA,BAnyB
UB,CC,D,UAnyC
UUAnyAnyU


Four-part score
CCUD

Total Score
C
1.2 Impact on plant community
Consider the cumulative ecological impact of this species to the plant communities it invades. Give more weight to changes in plant composition, structure, and interactions that involve rare or keystone species or rare community types. Examples of severe impacts include:
- formation of stands dominated (>75% cover) by the species;
- occlusion (>75% cover) of a native canopy, including a water surface, that eliminates or degrades layers below;
- significant reduction or extirpation of populations of one or more native species.

Examples of impacts usually less than severe include:
- reduction in propagule dispersal, seedling recruitment, or survivorship of native species;
- creation of a new structural layer, including substantial thatch or litter, without elimination or replacement of a pre-existing layer;
- change in density or depth of a structural layer;
- change in horizontal distribution patterns or fragmentation of a native community;
- creation of a vector or intermediate host of pests or pathogens that infect native plant species.

Select the one letter below that best describes this species’ impact on community composition, structure and interactions:
A. Severe alteration of plant community composition, structure, or interactions.
B. Moderate alteration of plant community composition.
C. Minor alteration of community composition.
D. Negligible impact known; causes no perceivable change in community composition, structure, or interactions.
U. Unknown.
C. Minor Reviewed Scientific Publication
1.3 Impact on higher trophic levels
Consider the cumulative impact of this species on the animals, fungi, microbes, and other organisms in the communities that it invades. Although a non-native species may provide resources for one or a few native species (e.g. by providing food, nesting sites, etc.), the ranking should be based on the species’ net impact on all native species. Give more weight to changes in composition and interactions involving rare or keystone species or rare community types.
Examples of severe impacts include:
- extirpation or endangerment of an existing native species or population;
- elimination or significant reduction in native species’ nesting or foraging sites, cover, or other critical resources (i.e., native species habitat), including migratory corridors.

Examples of impacts that are usually less than severe include:
- minor reduction in nesting or foraging sites, cover, etc. for native animals;
- minor reduction in habitat connectivity or migratory corridors;
- interference with native pollinators;
- injurious components, such as awns or spines that damage the mouth and gut of native wildlife species, or production of anti-digestive or acutely toxic chemical that can poison native wildlife species.

Select the one letter below that best describes this species’ impact on community composition and interactions:
A. Severe alteration of higher trophic populations, communities, or interactions.
B. Moderate alteration of higher trophic level populations, communities, or interactions.
C. Minor alteration of higher trophic level populations, communities or interactions.
D. Negligible impact; causes no perceivable change in higher trophic level populations, communities, or interactions.
E. Unknown.
E. Unknown
1.4 Impact on genetic integrity
Consider whether the species can hybridize with and influence the proportion of individuals with non-native genes within populations of native species. Mechanisms and possible outcomes include:
- production of fertile or sterile hybrids that can outcompete the native species;
- production of sterile hybrids that lower the reproductive output of the native species.

Select the one letter below that best describes this species’ impact on genetic integrity:
A. Severe (high proportion of individuals).
B. Moderate (medium proportion of individuals).
C. Minor (low proportion of individuals).
D. No known hybridization.
U. Unknown.
D. None Reviewed Scientific Publication
2.1 Role of anthropogenic and natural disturbance in establishment
Assess this species’ dependence on disturbance—both human and natural—for establishment in wildlands. Examples of anthropogenic disturbances include:
- grazing, browsing, and rooting by domestic livestock and feral animals;
- altered fire regimes, including fire suppression;
- cultivation;
- silvicultural practices;
- altered hydrology due to dams, diversions, irrigation, etc.;
- roads and trails;
- construction;
- nutrient loading from fertilizers, runoff, etc.

Examples of natural disturbance include:
- wildfire;
- floods;
- landslides;
- windthrow;
- native animal activities such as burrowing, grazing, or browsing.

Select the first letter in the sequence below that describes the ability of this species to invade wildlands:
A. Severe invasive potential—this species can establish independent of any known natural or anthropogenic disturbance.
B. Moderate invasive potential—this species may occasionally establish in undisturbed areas but can readily establish in areas with natural disturbances.
C. Low invasive potential—this species requires anthropogenic disturbance to establish.
D. No perceptible invasive potential—this species does not establish in wildlands (though it may persist from former cultivation).
U. Unknown.
C. Low Observational
Invasiveness
Section 2 Scoring Matrix
Total pointsScore
17-21A
11-16B
5-10C
0-4D
More than two U’sU


Total Points
9

Total Score
C
2.2 Local rate of spread with no management
Assess this species’ rate of spread in existing localized infestations where the proportion of available habitat invaded is still small when no management measures are implemented.

Select the one letter below that best describes the rate of spread:
A. Increases rapidly (doubling in <10 years)
B. Increases, but less rapidly
C. Stable
D. Declining
U. Unknown
B. Increases less rapidly Observational
2.3 Recent trend in total area infested within state
Assess the overall trend in the total area infested by this species statewide. Include current management efforts in this assessment and note them.

Select the one letter below that best describes the current trend:
A. Increasing rapidly (doubling in total range statewide in <10 years)
B. Increasing, but less rapidly
C. Stable
D. Declining
U. Unknown
C. Stable Other Published Material
2.4 Innate reproductive potential
(see Worksheet A)
Assess the innate reproductive potential of this species. Worksheet A is provided for computing the score.
B. Moderate Reviewed Scientific Publication
2.5 Potential for human-caused dispersal
Assess whether this species is currently spread—or has high potential to be spread—by direct or indirect human activity. Such activity may enable the species to overcome natural barriers to dispersal that would not be crossed otherwise, or it may simply increase the natural dispersal of the species. Possible mechanisms for dispersal include:
- commercial sales for use in agriculture, ornamental horticulture, or aquariums;
- use as forage, erosion control, or revegetation;
- presence as a contaminant (seeds or propagules) in bulk seed, hay, feed, soil, packing materials, etc.;
- spread along transportation corridors such as highways, railroads, trails, or canals;
- transport on boats or boat trailers.

Select the one letter below that best describes human-caused dispersal and spread:
A. High—there are numerous opportunities for dispersal to new areas.
B. Moderate—human dispersal occurs, but not at a high level.
C. Low—human dispersal is infrequent or inefficient.
D. Does not occur.
U. Unknown.
C. Low Other Published Material
2.6 Potential for natural long-distance dispersal
We have chosen 1 km as the threshold of "long-distance." Assess whether this species is frequently spread, or has high potential to be spread, by animals or abiotic mechanisms that can move seed, roots, stems, or other propagules this far. The following are examples of such natural long-distance dispersal mechanisms:
- the species’ fruit or seed is commonly consumed by birds or other animals that travel long distances;
- the species’ fruits or seeds are sticky or burred and cling to feathers or hair of animals;
- the species has buoyant fruits, seeds, or other propagules that are dispersed by flowing water;
- the species has light propagules that promote long-distance wind dispersal;
- The species, or parts of it, can detach and disperse seeds as they are blown long distances (e.g., tumbleweed).

Select the one letter below that best describes natural long-distance dispersal and spread:
A. Frequent long-distance dispersal by animals or abiotic mechanisms.
B. Occasional long-distance dispersal by animals or abiotic mechanisms.
C. Rare dispersal more than 1 km by animals or abiotic mechanisms.
D. No dispersal of more than 1 km by animals or abiotic mechanisms.
U. Unknown.
C. Rare Observational
2.7 Other regions invaded
Assess whether this species has invaded ecological types in other states or countries outside its native range that are analogous to ecological types not yet invaded in your state (see Worksheets B, C, and D for California, Arizona, and Nevada, respectively, in Part IV for lists of ecological types). This information is useful in predicting the likelihood of further spread within your state.

Select the one letter below that best describes the species' invasiveness in other states or countries, outside its native range.
A. This species has invaded 3 or more ecological types elsewhere that exist in your state and are as yet not invaded by this species (e.g. it has invaded Mediterranean grasslands, savanna, and maquis in southern Europe, which are analogous to California grasslands, savanna, and chaparral, respectively).
B. Invades 1 or 2 ecological types that exist but are not yet invaded in your state.
C. Invades elsewhere but only in ecological types that it has already invaded in the state.
D. Not known as an escape anywhere else.
U. Unknown.
C. Already invaded Reviewed Scientific Publication
3.1 Ecological amplitude/Range
(see Worksheet C)
Refer to Worksheet C and select the one letter below that indicates the number of different ecological types that this species invades.
A. Widespread—the species invades at least three major types or at least six minor types.
B. Moderate—the species invades two major types or five minor types.
C. Limited—the species invades only one major type and two to four minor types.
D. Narrow—the species invades only one minor type.
U. Unknown.
A. Widespread Other Published Material
Distribution
Section 3 Scoring Matrix
Q 3.1Q 3.2Score
AA, BA
AC,D,UB
BAA
BB,CB
BDC
CA,BB
CC,DC
DAB
DB,CC
DDD
A,BUC
C,DUD
UUU


Total Score
B
3.2 Distribution/Peak frequency
(see Worksheet C)
To assess distribution, record the letter that corresponds to the highest percent infested score entered in Worksheet C for any ecological type.
D. Very low Observational

Table 3. Documentation

Scores are explained in the "Criteria for Categorizing Invasive Non-Native Plants that Threaten Wildlands".
Short citations may be used in this table. List full citations at end of this table.

Section 1: Impact

Reviewed Scientific Publication C Question 1.1 Impact on abiotic ecosystem processes
Consider the impact on the natural range and variation of abiotic ecosystem processes and system-wide parameters in ways that significantly diminish the ability of native species to survive and reproduce. Alterations that determine the types of communities that can exist in a given area are of greatest concern. Examples of abiotic processes include:
- fire occurrence, frequency, and intensity;
- geomorphological changes such as erosion and sedimentation rates;
- hydrological regimes, including soil water table;
- nutrient and mineral dynamics, including salinity, alkalinity, and pH;
- light availability (e.g. when an aquatic invader covers an entire water body that would otherwise be open).

Select the one letter below that best describes this species’ most severe impact on an abiotic ecosystem process:
A. Severe, possibly irreversible, alteration or disruption of an ecosystem process.
B. Moderate alteration of an ecosystem process.
C. Minor alteration of an ecosystem process.
D. Negligible perceived impact on an ecosystem process.
U. Unknown.
Identify ecosystem processes impacted:
Nutrient levels and distribution are altered within the soil profile, and have long lasting effects. Allelopathic. A. melanoxylon has the ability to fix nitrogen with rates of N-fixation ranging from 0.1 to 32 kg ha-1 year-1. Organic matter and nitrogen levels are increased with a decrease in C:N ratios. Soil nutrient enrichement and nutrient mineralization patterns can persist long after Acacia removal.

Sources of information:
Haubensak, K. 1999. Acacia melanoxylon. Channel Island National Park Service Literature Review. Unpublished. Stock, W.D., Wienand, K.T. and Baker, A.C. 1995. Impacts of invading N2-fixing Acacia species on patterns of nutrient cyling in tow Cape ecosystems: evidence from soil incubation studies and 15N natural abundance values. Oecologia. 101(3):375-382. D' Antonio, C. and Meyerson, L.A. 2002. Exotic plant species as problems and solutions in ecological restoration: a synthesis. Restoration Ecology 10(4):703-713. Daehler, C. No date. Acacia melanoxylon; Australian blackwood. Kauluanani Urban Forestry Program and U.S. Forest Service. Australian/New Zealand Weed Risk Assessment adapted for Hawai’i.

Reviewed Scientific Publication C Question 1.2 Impact on plant community composition,
structure, and interactions
Consider the cumulative ecological impact of this species to the plant communities it invades. Give more weight to changes in plant composition, structure, and interactions that involve rare or keystone species or rare community types. Examples of severe impacts include:
- formation of stands dominated (>75% cover) by the species;
- occlusion (>75% cover) of a native canopy, including a water surface, that eliminates or degrades layers below;
- significant reduction or extirpation of populations of one or more native species.

Examples of impacts usually less than severe include:
- reduction in propagule dispersal, seedling recruitment, or survivorship of native species;
- creation of a new structural layer, including substantial thatch or litter, without elimination or replacement of a pre-existing layer;
- change in density or depth of a structural layer;
- change in horizontal distribution patterns or fragmentation of a native community;
- creation of a vector or intermediate host of pests or pathogens that infect native plant species.

Select the one letter below that best describes this species’ impact on community composition, structure and interactions:
A. Severe alteration of plant community composition, structure, or interactions.
B. Moderate alteration of plant community composition.
C. Minor alteration of community composition.
D. Negligible impact known; causes no perceivable change in community composition, structure, or interactions.
U. Unknown.
Identify type of impact or alteration:
A. melanoxylon inhibits the germination and growth of native species in the understory. Acacia spp. form dense monospecific stands in South Africa, but not in Hawai'i nor on Santa Catalina Island. Minor impacts in California. Alleolopathic compounds are released in the decomposition of A. melanoxylon leaf litter.

Sources of information:
Souto, X.C., Gonzalez, L. and Reigosa, M.J. 1994. Comparative analysis of allelopathic effects produced by four forestry species durning decompostion prosess in their soils in Galicia (NW Spain). Journal of Chemical Ecology, 20(11):3005-3015. Haubensak, K. 1999. Acacia melanoxylon. Channel Island National Park Service Literature Review. Unpublished. Stock, W.D., Wienand, K.T. and Baker, A.C. 1995. Impacts of invading N2-fixing Acacia species on patterns of nutrient cyling in tow Cape ecosystems: evidence from soil incubation studies and 15N natural abundance values. Oecologia. 101(3):375-382. Knapp, J.J. 2004. Catalina Invasive Plant Ranking Plan for the Catalina Island Conservancy. Unpublished. Elkhorn Slough National Estuarine Research Reserve. 2000. Weed control by species. Elkhorn Slough National Estuarine Research Reserve. Pp. 1-57. Peter Warner, California Dept. of Parks and Recreation, pers. obs. Bob Case, California Native Plant Society, pers. obs.

U Question 1.3 Impact on higher trophic levels
Consider the cumulative impact of this species on the animals, fungi, microbes, and other organisms in the communities that it invades. Although a non-native species may provide resources for one or a few native species (e.g. by providing food, nesting sites, etc.), the ranking should be based on the species’ net impact on all native species. Give more weight to changes in composition and interactions involving rare or keystone species or rare community types.
Examples of severe impacts include:
- extirpation or endangerment of an existing native species or population;
- elimination or significant reduction in native species’ nesting or foraging sites, cover, or other critical resources (i.e., native species habitat), including migratory corridors.

Examples of impacts that are usually less than severe include:
- minor reduction in nesting or foraging sites, cover, etc. for native animals;
- minor reduction in habitat connectivity or migratory corridors;
- interference with native pollinators;
- injurious components, such as awns or spines that damage the mouth and gut of native wildlife species, or production of anti-digestive or acutely toxic chemical that can poison native wildlife species.

Select the one letter below that best describes this species’ impact on community composition and interactions:
A. Severe alteration of higher trophic populations, communities, or interactions.
B. Moderate alteration of higher trophic level populations, communities, or interactions.
C. Minor alteration of higher trophic level populations, communities or interactions.
D. Negligible impact; causes no perceivable change in higher trophic level populations, communities, or interactions.
E. Unknown.
Identify type of impact or alteration:
unknown

Sources of information:

Reviewed Scientific Publication D Question 1.4 Impact on genetic integrity
Consider whether the species can hybridize with and influence the proportion of individuals with non-native genes within populations of native species. Mechanisms and possible outcomes include:
- production of fertile or sterile hybrids that can outcompete the native species;
- production of sterile hybrids that lower the reproductive output of the native species.

Select the one letter below that best describes this species’ impact on genetic integrity:
A. Severe (high proportion of individuals).
B. Moderate (medium proportion of individuals).
C. Minor (low proportion of individuals).
D. No known hybridization.
U. Unknown.
Identify impacts:
There is only one native Acacia in California, A. greggii (catclaw acacia) and it is an uncommon species of desert washes. Hybridization seems unlikely.

Sources of information:
(1) Hickman, J.C. (ed.). 1993. The Jepson manual of higher plants of California. Pp. 581-582. University of California Press, Berkeley.

Section 2: Invasiveness

Observational C Question 2.1 Role of anthropogenic and natural disturbance
in establishment
Assess this species’ dependence on disturbance—both human and natural—for establishment in wildlands. Examples of anthropogenic disturbances include:
- grazing, browsing, and rooting by domestic livestock and feral animals;
- altered fire regimes, including fire suppression;
- cultivation;
- silvicultural practices;
- altered hydrology due to dams, diversions, irrigation, etc.;
- roads and trails;
- construction;
- nutrient loading from fertilizers, runoff, etc.

Examples of natural disturbance include:
- wildfire;
- floods;
- landslides;
- windthrow;
- native animal activities such as burrowing, grazing, or browsing.

Select the first letter in the sequence below that describes the ability of this species to invade wildlands:
A. Severe invasive potential—this species can establish independent of any known natural or anthropogenic disturbance.
B. Moderate invasive potential—this species may occasionally establish in undisturbed areas but can readily establish in areas with natural disturbances.
C. Low invasive potential—this species requires anthropogenic disturbance to establish.
D. No perceptible invasive potential—this species does not establish in wildlands (though it may persist from former cultivation).
U. Unknown.
Describe role of disturbance:
In California, present in sites with human disturbance (1, 3). Germination follows disturbance (2).

Sources of information:
(1) Hickman, J. C. (ed.) 1993. The Jepson Manual, Higher Plants of California. University of California Press. Berkeley, CA (2) Tunison, T. 1991. Element Stewardship Abstract for Acacia melanoxylon. The Nature Conservancy. Arlington, Virginia. Available: http://tncweeds.ucdavis.edu (3) Peter Warner, California Dept. of Parks and Recreation, pers. obs.

Observational B Question 2.2 Local rate of spread with no management
Assess this species’ rate of spread in existing localized infestations where the proportion of available habitat invaded is still small when no management measures are implemented.

Select the one letter below that best describes the rate of spread:
A. Increases rapidly (doubling in <10 years)
B. Increases, but less rapidly
C. Stable
D. Declining
U. Unknown
Describe rate of spread:
Controlled in the past on Catalina Island, and many seedlings were detected in 2003 (1). Limited invasiveness on the north coast (2)

Sources of information:
(1) Knapp, J.J. 2004. Catalina Invasive Plant Ranking Plan for the Catalina Island Conservancy. Unpublished (2) Warner, Peter, California State Parks, Mendocino. pers. comm. E-mail 5/18/05

Other Published Material C Question 2.3 Recent trend in total area infested within state
Assess the overall trend in the total area infested by this species statewide. Include current management efforts in this assessment and note them.

Select the one letter below that best describes the current trend:
A. Increasing rapidly (doubling in total range statewide in <10 years)
B. Increasing, but less rapidly
C. Stable
D. Declining
U. Unknown
Describe trend:
Because Peter Warner reports it as being rarely invasive, it is probably not spreading appreciably in the state.

Sources of information:
(1) Warner, Peter, California State Parks, Mendocino. pers. comm. E-mail 5/18/05

Reviewed Scientific Publication B Question 2.4 Innate reproductive potential
Assess the innate reproductive potential of this species. Worksheet A is provided for computing the score.
Describe key reproductive characteristics:
Large long lived soil-seed bank. Reaches reproductive maturity between two to five years. Has coppice resprouts and suckers after disturbance, and germinates readily following fire. Reproduces by seed and root sprouts. In Hawai'i, A. melanoxylon mainly reproduces from root sprouting, but viable seeds are produced from forestry plantings. In California, fruits ripen from July to November. Seeds remain viable for over 50 years in the soil. Seed bank of a related invasive Acacia (A. longifolia), was 50 times larger in the invaded habitat than in the native one. On Catalina Island- numerous seedlings and several large adults were recorded within and just outside Avalon Valley where most recorded populations were planted in private yards and as street tree plantings. Mature naturalized plants were in fruit; however, the viablity of these seeds are unknown, but due to the frequent seedlings detected, seeds are presumed viable.

Sources of information:
Haubensak, K. 1999. Acacia melanoxylon. Channel Island National Park Service Literature Review. Unpublished. Schierenbeck, K.A., Gallagher, K.G. and Holt, J.N. 1998. The genetics and demography of invasive plant species. Fremontia 26(4):19-23. Brown, K. and Brooks, K. 2002. Bushland Weeds: a practical guide to their management with case studies from the Swan Coastal Plain and beyond. Environmental Weeds Action Network, Greenwood Australia. Young, J.A. and C.G. Young. 1992. Seeds of woody plants in North America. Portland, Oregon: Dioscorides Press. Pp. 356-357.

Other Published Material C Question 2.5 Potential for human-caused dispersal
Assess whether this species is currently spread—or has high potential to be spread—by direct or indirect human activity. Such activity may enable the species to overcome natural barriers to dispersal that would not be crossed otherwise, or it may simply increase the natural dispersal of the species. Possible mechanisms for dispersal include:
- commercial sales for use in agriculture, ornamental horticulture, or aquariums;
- use as forage, erosion control, or revegetation;
- presence as a contaminant (seeds or propagules) in bulk seed, hay, feed, soil, packing materials, etc.;
- spread along transportation corridors such as highways, railroads, trails, or canals;
- transport on boats or boat trailers.

Select the one letter below that best describes human-caused dispersal and spread:
A. High—there are numerous opportunities for dispersal to new areas.
B. Moderate—human dispersal occurs, but not at a high level.
C. Low—human dispersal is infrequent or inefficient.
D. Does not occur.
U. Unknown.
Identify dispersal mechanisms:
Acacia species are commonly planted for landscaping and commercial purposes. No information on how often it escapes (1, 2). In Mendocino County, usually seen along old fencelines or at homestead sites. This species is rarely planted (3).

Sources of information:
(1) Brenzel, K. N. 2001. Sunset Western Garden Book. Sunset Publishing Company, Menlo Park, CA. (2) Pemberton, R.W. 1985. Naturalized weeds and the prospects for their biological control in California. Fremontia 13(2):3-9. (3) Warner, Peter, California State Parks, Mendocino. pers. comm. E-mail 5/18/05

Observational C Question 2.6 Potential for natural long-distance dispersal
We have chosen 1 km as the threshold of "long-distance." Assess whether this species is frequently spread, or has high potential to be spread, by animals or abiotic mechanisms that can move seed, roots, stems, or other propagules this far. The following are examples of such natural long-distance dispersal mechanisms:
- the species’ fruit or seed is commonly consumed by birds or other animals that travel long distances;
- the species’ fruits or seeds are sticky or burred and cling to feathers or hair of animals;
- the species has buoyant fruits, seeds, or other propagules that are dispersed by flowing water;
- the species has light propagules that promote long-distance wind dispersal;
- The species, or parts of it, can detach and disperse seeds as they are blown long distances (e.g., tumbleweed).

Select the one letter below that best describes natural long-distance dispersal and spread:
A. Frequent long-distance dispersal by animals or abiotic mechanisms.
B. Occasional long-distance dispersal by animals or abiotic mechanisms.
C. Rare dispersal more than 1 km by animals or abiotic mechanisms.
D. No dispersal of more than 1 km by animals or abiotic mechanisms.
U. Unknown.
Identify dispersal mechanisms:
Birds such as European starlings disperse A. cyclops in South Africa (1). On Catalina Island, present three miles from nearest human habitatation (2).

Sources of information:
(1) Richardson, D.M., Allsopp, N., D’Antonio, C.M., Milton, S.J. and Rejmanek, M. 2000. Plant invasions- role of mutualisms. Biological Reviews, 75:65-93 (2) John Knapp, Catalina Island Conservancy, pers. obs..

Reviewed Scientific Publication C Question 2.7 Other regions invaded
Assess whether this species has invaded ecological types in other states or countries outside its native range that are analogous to ecological types not yet invaded in your state (see Worksheets B, C, and D for California, Arizona, and Nevada, respectively, in Part IV for lists of ecological types). This information is useful in predicting the likelihood of further spread within your state.

Select the one letter below that best describes the species' invasiveness in other states or countries, outside its native range.
A. This species has invaded 3 or more ecological types elsewhere that exist in your state and are as yet not invaded by this species (e.g. it has invaded Mediterranean grasslands, savanna, and maquis in southern Europe, which are analogous to California grasslands, savanna, and chaparral, respectively).
B. Invades 1 or 2 ecological types that exist but are not yet invaded in your state.
C. Invades elsewhere but only in ecological types that it has already invaded in the state.
D. Not known as an escape anywhere else.
U. Unknown.
Identify other regions:
Native to Australia. Invades South Africa (fynbos), Spain, and New Zealand. Already inhabits several different habitats in California, although at low levels (see 3.1).

Sources of information:
Brown, K. and Brooks, K. 2002. Bushland Weeds: a practical guide to their management with case studies from the Swan Coastal Plain and beyond. Environmental Weeds Action Network, Greenwood Australia. Stock, W.D., Wienand, K.T. and Baker, A.C. 1995. Impacts of invading N2-fixing Acacia species on patterns of nutrient cyling in tow Cape ecosystems: evidence from soil incubation studies and 15N natural abundance values. Oecologia. 101(3):375-382.

Section 3: Distribution

Other Published Material A Question 3.1 Ecological amplitude/Range
Refer to Worksheet C and select the one letter below that indicates the number of different ecological types that this species invades.
A. Widespread—the species invades at least three major types or at least six minor types.
B. Moderate—the species invades two major types or five minor types.
C. Limited—the species invades only one major type and two to four minor types.
D. Narrow—the species invades only one minor type.
U. Unknown.
Describe ecological amplitude, identifying date of source information and approximate date of introduction to the state, if known:
Present in Mendocino, Sonoma, Marin, Solano, San Mateo, Santa Cruz, Santa Clara, Santa Barbara, and San Diego counties (1). Planted on Catalina Island prior to 1923 and fruiting luxuriantly, but showed no signs of naturalization (2). By 1966, several populations had become naturalized around Avalon (3). Present in chaparral and coastal prairie on Catalina Island (4), and occasionally spreads into scrub, riparian zones, closed cone pine forest, mixed evergreen forest, andn cismontane woodlands in northern California (5).

Sources of information:
(1) USDA, NRCS. 2005. The PLANTS Database, Version 3.5 (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA. (2) Millspaugh, C.F. and Nuttall, L.W. 1923. Flora of Santa Catalina Island. P. 154. Field Museum of Natural History, Botany v.5. Chicago. (3) Thorne, R.F. 1967. A flora of Santa Catalina Island, California. Aliso, 6(3):1-77. (4) Knapp, J.J. 2004. Catalina Invasive Plant Ranking Plan for the Catalina Island Conservancy. Unpublished. (5) Warner, Peter, California State Parks, Mendocino. pers. comm. E-mail 5/18/05

Observational D Question 3.2 Distribution/Peak frequency
To assess distribution, record the letter that corresponds to the highest percent infested score entered in Worksheet C for any ecological type.
Describe distribution:
Very low occurrence in all habitat types.

Sources of information:
(1) Warner, Peter, California State Parks, Mendocino. pers. comm. E-mail 5/18/05

Worksheet A - Innate reproductive potential

Reaches reproductive maturity in 2 years or less No
Dense infestations produce >1,000 viable seed per square meter No
Populations of this species produce seeds every year. Yes, 1 points
Seed production sustained over 3 or more months within a population annually No
Seeds remain viable in soil for three or more years Yes, 2 points
Viable seed produced with both self-pollination and cross-pollination Unknown
Has quickly spreading vegetative structures (rhizomes, roots, etc.) that may root at nodes No
Fragments easily and fragments can become established elsewhere No
Resprouts readily when cut, grazed, or burned Yes, 1 points
Total points: 4
Total unknowns: 1
Total score: B
Scoring Criteria for Worksheet A
A. High reproductive potential (6 or more points).
B. Moderate reproductive potential (4-5 points).
C. Low reproductive potential (3 points or less and less than 3 Unknowns).
U. Unknown (3 or fewer points and 3 or more Unknowns).
Note any related traits:
Return to Table 2

Worksheet B - Arizona Ecological Types is not included here


Worksheet C - California Ecological Types
 
(sensu Holland 1986)

Major Ecological Types Minor Ecological Types Code
A means >50% of type occurrences are invaded;
B means >20% to 50%;
C means >5% to 20%;
D means present but ≤5%;
U means unknown (unable to estimate percentage of occurrences invaded)
Marine Systemsmarine systems
Freshwater and Estuarine lakes, ponds, reservoirs
Aquatic Systemsrivers, streams, canals
estuaries
Dunescoastal
desert
interior
Scrub and Chaparralcoastal bluff scrub
coastal scrubD. < 5%
Sonoran desert scrub
Mojavean desert scrub (incl. Joshua tree woodland)
Great Basin scrub
chenopod scrub
montane dwarf scrub
Upper Sonoran subshrub scrub
chaparralD. < 5%
Grasslands, Vernal Pools, coastal prairieD. < 5%
Meadows, and other Herbvalley and foothill grassland
CommunitiesGreat Basin grassland
vernal pool
meadow and seep
alkali playa
pebble plain
Bog and Marshbog and fen
marsh and swamp
Riparian and Bottomland habitatriparian forest
riparian woodlandD. < 5%
riparian scrub (incl.desert washes)
Woodlandcismontane woodlandD. < 5%
piñon and juniper woodland
Sonoran thorn woodland
Forestbroadleaved upland forest
North Coast coniferous forest
closed cone coniferous forestD. < 5%
lower montane coniferous forest
upper montane coniferous forest
subalpine coniferous forest
Alpine Habitatsalpine boulder and rock field
alpine dwarf scrub
Amplitude (breadth)  
Distribution (highest score)  
Return to Table 2

Addendum J - Jepson Regions Infested
 
Click here for a map of Jepson regions

Infested Jepson Regions:
Check the boxes to indicate the Jepson floristic provinces in which this species is found.














Addendum L - External Links & Resources

Cal-IPC Plant Profile
The Cal-IPC Plant Profile for this species.
http://www.cal-ipc.org/ip/management/plant_profiles/Acacia_melanoxylon.php
Calflora Plant Profile:
The Calflora Plant Profile for this species.
http://www.calflora.org/cgi-bin/species_query.cgi?where-calrecnum=36
CalWeedMapper:
Load CalWeedMapper with this species already selected.
http://calweedmapper.cal-ipc.org/maps/?species=103