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SUMMARY

Rating	Alert	Impact	Invasiveness	Distribution	Doc.
Not listed	N	B	B	U	2
Comments:
Rating 1 = High 2 = Moderate 3 = Limited 4 = Evaluated, not listed		Alert Y = Yes N = No	Scores A = Severe B = Moderate C = Limited D = None U = Unknown	Documentation 4 = Reviewed scientific publications 3 = Other published material 2 = Observational 1 = Anecdotal 0 = No information

Scores

1.1	1.2	1.3	1.4	2.1	2.2	2.3	2.4	2.5	2.6	2.7	3.1	3.2
B	A	U	C	A	C	D	B	A	D	A	U	U

IMPACT

1.1 Impact on abiotic ecosystem processes - B

Identify ecosystem processes impacted: compared to native grassland species: above-ground biomass greater, litter accumulation greater, hence soil temperature likely lower ; likely effects on fire intensity, etc.; possible effects on nitrogen cycle; might increase (due to shading) or decrease (due to uptake) soil moisture.

Sources of information: pers. obs; T. Basham pers. comm.; T. Basham dissertation, when completed, will address many of these processes

Documentation: Observational

1.2 Impact on plant community composition, structure, and interactions - A

Identify type of impact or alteration: compared to plots dominated by native grassland species, species richness can be greatly reduced. near-monocultures of B. ischaemum var songarica are not uncommon.

Sources of information: Gabbard and Fowler 2007

Documentation: Rev'd, Sci. Pub'n

1.3 Impact on higher trophic levels - U

Identify type of impact or alteration: unknown, but probably large where B. ischaemum var songarica is abundant

Sources of information: Sources of information: none, but note that published studies of B. ischaemum var ischaemum further north have documented impacts

Documentation: No Information

1.4 Impact on genetic integrity - C

Identify impacts: according to anecdotal information, it may self –fertilize or be an apomict, and may be an aneuploid series

Sources of information: D. Overath is working on the genetics of this species; Gould 1975 reports several chromosome numbers for this variety, which suggests aneuploidy and hence apomixis. There are native congenerics, so the risk should be investigated

Documentation: Anecdotal

IMPACT: B A U C = B

INVASIVENESS

2.1 Role of anthropogenic and natural disturbance in establishment - A

Describe role of disturbance: highly fire, grazing, and mowing tolerant, but does not need any of these to form dense monocultures; not restricted to roadsides but often abundant there

Sources of information: Fowler and Gabbard 2007; Fowler unpublished

Documentation: Rev'd, Sci. Pub'n

2.2 Local rate of spread with no management - C

Describe rate of spread: relatively slow; primarily spreading from established patches

Sources of information: Fowler unpublished

Documentation: Observational

2.3 Recent trend in total area infested within state - D

Describe trend: my guess is that it continues to increase

Sources of information: conversations with land managers; casual pers. obs

Documentation: Anecdotal

2.4 Innate reproductive potential - B

Describe key reproductive characteristics: bunchgrass; sets abundant seed, but seed viability often fairly low, apparently due to fungus

Sources of information: Gabbard 2003 (Ph.D. dissertation) provides excellent demographic data on this species; Alofs unpublished.

Documentation: Other Pub. Mat'l

2.5 Potential for human-caused dispersal - A

Identify dispersal mechanisms: vehicles; mowing machines are likely. Note that it is sold commercially and deliberately planted, especially for erosion control.

Sources of information: Gabbard and Fowler 2007

Documentation: Rev'd, Sci. Pub'n

2.6 Potential for natural long-distance dispersal - D

Identify dispersal mechanisms: none known

Sources of information: the pattern of local spread (Fowler unpublished) strongly suggests that natural dispersal is usually limited to quite short distances; does not stick in socks but might be moved by mud on hooves, paws

Documentation: Anecdotal

2.7 Other regions invaded - A

Identify other regions: based on Turner 2003, this variety has already spread across the southern half of Texas, suggesting a climatic limit. B. ischaemum var ischamum is found in OK, KA, so we can anticipate it spreading across northern TX

Sources of information: Turner 2003

Documentation: Rev'd, Sci. Pub'n

INVASIVENESS: A C D B A D A = B

DISTRIBUTION

3.1 Ecological amplitude - U

Describe ecological amplitude, identifying date of source information and approximate date of introduction to the state, if known: we have information only for the eastern Edwards Plateau. In that region, the amplitude would score ‘A’

Sources of information: for the eastern Edwards Plateau only: Gabbard and Fowler 2007; Fowler unpublished; pers comm. from various land managers

Documentation: No Information

3.2 Distribution/Peak frequency - U

Identify type of impact or alteration:

Sources of information:

Documentation: No Information

IMPACT: U U = U

TEXAS ECOREGIONS

Source: Level III and IV Ecoregions of Texas. Griffith, G.E., Bryce, S.A., Omernik, J.M., Comstock, J.A., Rogers, A.C., Harrison, B., Hatch, S.L., and Bezanson, D., 2004, Ecoregions of Texas, U.S. Environmental Protection Agency, Corvallis, OR.

Score: 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.

Code	Level III	Level IV	Score
ER01	Arizona/New Mexico Mountains	Chihuahuan Desert Slopes	U
		Montane Woodlands	A
ER02	Chihuahuan Deserts	Chihuahuan Basins and Playas	A
		Chihuahuan Desert Grasslands	A
		Low Mountains and Bajadas	A
		Chihuahuan Montane Woodlands	A
		Stockton Plateau	A
ER03	High Plains	Rolling Sand Plains	A
		Canadian/Cimarron High Plains	A
		Llano Estacado	A
		Shinnery Sands	A
		Arid Llano Estacado	A
ER04	Southwestern Tablelands	Canadian/Cimarron Breaks	A
		Flat Tablelands and Valleys	A
		Caprock Canyons, Badlands, and Breaks	A
		Semiarid Canadian Breaks	A
ER05	Central Great Plains	Red Prairie	A
		Broken Red Plains	A
		Limestone Plains	A
ER06	Cross Timbers	Eastern Crosstimbers	A
		Western Crosstimbers	A
		Grand Prairie	A
		Limestone Cut Plain	A
		Carbonate Cross Timbers	A
ER07	Edwards Plateau	Edwards Plateau Woodland	A
		Llano Uplift	A
		Balcones Canyonlands	A
		Semiarid Edwards Plateau	A
ER08	Southern Texas Plains	Northern Nueces Alluvial Plains	A
		Semiarid Edwards Bajadas	A
		Texas-Tamaulipan Thornscrub	A
		Rio Grande Floodplain and Terraces	A
ER09	Texas Blackland Prairies	Northern Blackland Prairies	A
		Southern Blackland/Fayette Prairie	A
		Floodplains and Low Terraces	A
ER10	East Central Texas Plains	Northern Post Oak Savanna	A
		Southern Post Oak Savanna	A
		San Antonio Prairie	A
		Northern Prairie Outliers	A
		Bastrop Lost Pines	A
		Floodplains and Low Terraces	A
ER11	Western Gulf Coastal Plain	Northern Humid Gulf Coastal Prairies	A
		Southern Subhumid Gulf Coastal Prairies	A
		Floodplains and Low Terraces	A
		Coastal Sand Plain	A
		Lower Rio Grande Valley	A
		Lower Rio Grande Alluvial Floodplain	A
		Texas-Louisiana Coastal Marshes	A
		Mid-Coast Barrier Islands and Coastal Marshes	A
		Laguna Madre Barrier Islands and Coastal Marshes	A
ER12	South Central Plains	Tertiary Uplands	A
		Floodplains and Low Terraces	A
		Pleistocene Fluvial Terraces	A
		Southern Tertiary Uplands	A
		Flatwoods	A
		Red River Bottomland	A

EVALUATORS

Evaluation Date: 2009-10-04

Evaluator 1
Norma Fowler
University of Texas at Austin
512-471-1295
nfowler@uts.cc.utexas.edu
Section of Integrative Biology C0930, University of Texas, 1 University Station, Austin, TX 78712

Evaluator 2

REVIEW

Reviewers:
Review Date: 0000-00-00
Comments:

REFERENCES

Plant Score was not calculated because the guidelines do not contain scoring guidelines for the situation where the distribution score is ‘U’.

A Documentation average is requested but the guidelines do not contain information for quantifying it.