Brown Sedge (Carex disticha)

Present distribution

Scientific name:	Carex disticha Huds.
Common name(s):	Brown Sedge

Map showing the present distribution of this weed.

Habitat:

In its native range in Euro-Siberia it is dominant on tall sedge grasslands, depressions and floodplains (Kukkonen, Toivonen 1988), also grows on alluvial meadows (Kabucis, Rusina, Veen 2003), semi-natural grasslands, mires, shores (Luoto, Pykälä, Kuussaari 2003). It has been introduced to North America (Kukkonen, Toivonen 1988) specifically in a wet field in Collingwood, Great Lakes, Ontario where it is dominant (Catling, Reznicek, Brookes 1988). It is also “uncommon in Victoria, recorded in recent times only from boggy flats near Lake Condah” (Walsh, Entwisle 1994).

Potential distribution

Potential distribution produced from CLIMATE modelling refined by applying suitable landuse and vegetation type overlays with CMA boundaries

Map Overlays Used

Land Use:
Broadacre cropping; pasture irrigation; water

Ecological Vegetation Divisions
Coastal; swampy scrub; treed swampy wetland; lowland forest; damp forest; riparian; basalt grassland; alluvial plains grassland; riverine woodland/forest; freshwater wetland (ephemeral)

Colours indicate possibility of Carex disticha infesting these areas.

In the non-coloured areas the plant is unlikely to establish as the climate, soil or landuse is not presently suitable.

map showing the potential distribution of brown sedge

Red= Very high	Orange = Medium
Yellow = High	Green = Likely

Impact

QUESTION	COMMENTS	RATING	CONFIDENCE
Social
1. Restrict human access?	Stems 20 – 100 cm (Jermy, Tutin 1968) and forms monodominant stands (Kabucis, Rusina, Veen 2003) – low nuisance value. Impedes individual access to waterways	ml	mh
2. Reduce tourism?	“where groundwater regimes remained intact but management was neglected… communities were trans-formed to wet tall-herb fens… also a substantial loss of low-growing associates at Market Wilson” (incl. C. disticha) (Fojt, Harding 1995) – this change in height of vegetation may cause minor effects in aesthetics	ml	m
3. Injurious to people?	Sharply trigonous (Jermy, Tutin 1968); may cause minor cuts – may cause some physiological issues	ml	mh
4. Damage to cultural sites?	Stems 20 – 100 cm (Jermy, Tutin 1968) and forms monodominant stands (Kabucis, Rusina, Veen 2003) – may have a moderate visual effect	ml	m
Abiotic
5. Impact flow?	Although it occurs in fens (Fojt, Harding 1995), mires, ditches and shores (Luoto, Pykälä, Kuussaari 2003) it does not occur in flowing water – little or negligible affect on water flow	l	mh
6. Impact water quality?	Dominant species on tall sedge dominated grasslands on depressions and floodplains (Kabucis, Rusina, Veen 2003), water meadows (Monocotyledons), Species of semi-natural grasslands, mires, ditches, shores (Luoto, Pykälä, Kuussaari 2003) Mesotrophic fens and wet grasslands (Guswell 2005), and forms monodominant stands (Kabucis, Rusina, Veen 2003). It also grows in a fen that has an inflow from the polluted river Vecht (Symoens 1988) – likely to effect light levels, also thrives in polluted waters.	ml	m
7. Increase soil erosion?	Successful coloniser species of wet grassland (Rosenthal 2006). Forms a closed vegetation with other sedge species in Sweden (D’Hertefeldt, Falkengren-Gerup 2002). Monodominant stands (Kabucis, Rusina, Veen 2003) – not likely to leave bare soil, hence there is a low probability of large scale soil movement and a possibility it may decrease the probability of soil erosion	l	mh
8. Reduce biomass?	Dominant species on tall sedge dominated grasslands on depressions and floodplains (Kabucis, Rusina, Veen 2003), water meadows (Monocotyledons), Species of semi-natural grasslands, mires, ditches, shores (Luoto, Pykälä, Kuussaari 2003) – direct replacement of biomass by invader	ml	mh
9. Change fire regime?	Displaces low-growing associates (Fojt, Harding 1995) and it contributes to 100% litter accumulation in grassland depressions in Sweden (Regnell 1980) therefore may increase fuel, however it occurs in wet habitats (Kabucis, Rusina, Veen 2003, Luoto, Pykälä, Kuussaari 2003, Guswell 2005) – minor change to intensity of fire risk	ml	m
Community Habitat
10. Impact on composition (a) high value EVC	EVC = Creekline Grassy Woodland (E); CMA = Goulburn Broken; Bioregion = Victorian Riverina; VH CLIMATE potential. Monoculture within a specific layer	h	h
(b) medium value EVC	EVC = Riverine Grassy Woodland (D); CMA = North East; Bioregion = Victorian Riverina; VH CLIMATE potential. Monoculture within a specific layer	h	h
(c) low value EVC	EVC = Estuarine Wetland (LC); CMA = West Gippsland; Bioregion = Gippsland Plain; VH CLIMATE potential. Monoculture within a specific layer	h	h
11. Impact on structure?	Successful coloniser species of wet grassland (Rosenthal 2006). Forms a closed vegetation with other sedge species in Sweden (D’Hertefeldt, Falkengren-Gerup 2002). Monodominant stands (Kabucis, Rusina, Veen 2003) – forms monoculture	h	h
12. Effect on threatened flora?	Successful coloniser species of wet grassland (Rosenthal 2006). Monodominant stands (Kabucis, Rusina, Veen 2003). It is likely to effect threatened flora – however this is not yet determined	mh	l
Fauna
13. Effect on threatened fauna?	Successful coloniser species of wet grassland (Rosenthal 2006). Monodominant stands (Kabucis, Rusina, Veen 2003). It is likely to effect habitat and food sources of threatened fauna – however this is not yet determined	mh	l
14. Effect on non-threatened fauna?	Successful coloniser species of wet grassland (Rosenthal 2006) and forms monodominant stands (Kabucis, Rusina, Veen 2003). Displaces low-growing associates (Fojt, Harding 1995) and it contributes to 100% litter accumulation in grassland depressions in Sweden (Regnell 1980) – habitat changed dramatically, leading to the possible extinction of non-threatened fauna	h	m
15. Benefits fauna?	It is palatable for livestock (Hoffman, Cosyns, Lamoot 2005, Catling, Reznicek, Brookes 1988) and so may provide some assistance in food to herbivorous native fauna	mh	m
16. Injurious to fauna?	Sharply trigonous (Jermy, Tutin 1968); may cause minor cuts – may cause fauna to lose condition	ml	m
Pest Animal
17. Food source to pests?	Frequently bitten by Shetland Ponies in Belgium coastal dunes (Hoffman, Cosyns, Lamoot 2005) and “it is reported to be one of the most important forage plants in western Siberia” (Catling, Reznicek, Brookes 1988) –food source for wild horses	ml	mh
18. Provides harbor?	Stems 20 – 100 cm (Jermy, Tutin 1968) and forms monodominant stands (Kabucis, Rusina, Veen 2003). Cover is one of the most important habitat feature for both foxes (Saunders et al 1995) and rabbits (Williams et al 1995), indicating that a stand of C.disticha would provide ideal harbour for rabbits and foxes – capacity to provide harbour and permanent warrens for foxes and rabbits throughout the year	h	mh
Agriculture
19. Impact yield?	Grows in productive pastures (D’Hertefeldt, Falkengren-Gerup 2002) “In the USSR it is an important component of pastures and early hay. It is reported to be one of the most important forage plants in western Siberia” (Catling, Reznicek, Brookes 1988). Occurred in a wet fen where it had not previously existed only when management had ceased (Fojt, Harding 1995) Dominates ungrazed areas, although it exists in grazed areas to a lesser extent (Regnell 1980) – although it grows in pastures, it does not appear to dominate managed land, and is palatable – little or negligible affect on quantity of yield	l	mh
20. Impact quality?	Grows in productive pastures (D’Hertefeldt, Falkengren-Gerup 2002) “In the USSR it is an important component of pastures and early hay. It is reported to be one of the most important forage plants in western Siberia” (Catling, Reznicek, Brookes 1988). Occurred in a wet fen where it had not previously existed only when management had ceased (Fojt, Harding 1995) Dominates ungrazed areas, although it exists in grazed areas to a lesser extent (Regnell 1980) – although it grows in pastures, it does not appear to dominate managed land, and is palatable – little or negligible affect on quality	l	mh
21. Affect land value?	Grows in productive pastures (D’Hertefeldt, Falkengren-Gerup 2002) Occurred in a wet fen where it had not previously existed only when management had ceased (Fojt, Harding 1995) Dominates ungrazed areas, although it exists in grazed areas to a lesser extent (Regnell 1980) – although it grows in pastures, it does not appear to dominate managed land – little or no affect on land value	l	mh
22. Change land use?	Grows in productive pastures (D’Hertefeldt, Falkengren-Gerup 2002) Occurred in a wet fen where it had not previously existed only when management had ceased (Fojt, Harding 1995) Dominates ungrazed areas, although it exists in grazed areas to a lesser extent (Regnell 1980) – although it grows in pastures, it does not appear to dominate managed land – little or no change	l	mh
23. Increase harvest costs?	Grows in productive pastures (D’Hertefeldt, Falkengren-Gerup 2002) Occurred in a wet fen where it had not previously existed only when management had ceased (Fojt, Harding 1995) Dominates ungrazed areas, although it exists in grazed areas to a lesser extent (Regnell 1980) – although it grows in pastures, it does not appear to dominate managed land – little or no increase in harvest cost	l	mh
24. Disease host/vector?	No cases of this were covered in the literature.	m	l

Invasive

QUESTION	COMMENTS	RATING	CONFIDENCE
Establishment
1. Germination requirements?	Germinates best after a process of light stratification (Shutz 2000) – requires natural seasonal disturbance	mh	h
2. Establishment requirements?	Open habitat, wet soil moisture (Schutz 2000). Dominant species on tall sedge dominated grasslands on depressions and floodplains (Kabucis, Rusina, Veen 2003), water meadows (Monocotyledons), low survival in a dry, low-nutrient treatment (D’Hertefeldt, Falkengren-Gerup 2002) – requires more specific requirements to establish (open space)	ml	h
3. How much disturbance is required?	Species of semi-natural grasslands, mires, ditches, shores. Rare in Finland (Luoto, Pykälä, Kuussaari 2003) Increase in C. disticha adjacent to agricultural grasslands after the cessation of fertilizer applications (Kleijn et al 2004). Species of P-rich disturbed sites (Guswell 2005) – minor disturbed natural ecosystems (wetlands, grasslands)	mh	h
Growth/Competitive
4. Life form?	Occurs in fens (Fojt, Harding 1995), mires, ditches and shores (Luoto, Pykälä, Kuussaari 2003) – semi aquatic (some part of plant always in water)	h	h
5. Allelopathic properties?	None mentioned in the literature- unknown	m	l
6. Tolerates herb pressure?	Frequently bitten by Shetland Ponies in Belgium coastal dunes (Hoffman, Cosyns, Lamoot 2005). “ungrazed plots were dominated by C. disticha” (Regnell 1980). “In the USSR it is an important component of pastures and early hay. It is reported to be one of the most important forage plants in western Siberia” (Catling, Reznicek, Brookes 1988) – reproduction strongly inhibited by herbivory but still capable of vegetative propagule production; weed may still persist	ml	h
7. Normal growth rate?	Displaces low-growing associates (Fojt, Harding 1995). Successful coloniser species of wet grassland (Rosenthal 2006) and forms monodominant stands (Kabucis, Rusina, Veen 2003) – rapid growth rate that will exceed most other species of the same life form	h	mh
8. Stress tolerance to frost, drought, w/logg, sal. etc?	Salt tolerant (Tyler 1971) – tolerant to salinity “indicator of excessively wet weakly salinized soils” (Zvereva 1990) – tolerant to waterlogging Grows in an area where frost occurs in Belgium (Gerard et al 2008) – frost tolerant Occurred in a wet fen where it had not previously existed only when management (which included burning) had ceased (Fojt, Harding 1995), suggesting C. disticha is not tolerant of fire Low survival in a dry, low-nutrient treatment (D’Hertefeldt, Falkengren-Gerup 2002) – intolerant to drought	mh	mh
Reproduction
9. Reproductive system	Vegetative and sexual (Skytte Christiansen 1979)	h	mh
10. Number of propagules produced?	219 seeds per ramet (Kleyer, Pschlod 2004) – 50-1000	ml	mh
11. Propagule longevity?	Unknown	m	l
12. Reproductive period?	Ramets live 4 years or longer (D’Hertefeldt, Falkengren-Gerup 2002) – mature plant produces viable propagules for 3-10 years	mh	h
13. Time to reproductive maturity?	Unknown	m	l
Dispersal
14. Number of mechanisms?	Transport Mechanism in Great Lakes, Ontario, by Solid Ballast Water (OGL 2000), Water dispersed (Gerard et al 2008)	mh	h
15. How far do they disperse?	Transport Mechanism in Great Lakes, Ontario, by Solid Ballast Water (OGL 2000), Water dispersed (Gerard et al 2008) – likely to disperse greater than 1km	h	h

References

Catling PM, Reznicek AA and Brookes BS (1988) The separation of Carex disticha and Carex sartwellii and the status of Carex disticha in North America. Canadian Journal of Botany 66, 2323-2330

D’Hertefeldt T, Falkengren-Gerup U (2002) Extensive physiological integration in Carex arenaria and Carex disticha in relation to potassium and water availability. New Phytologist 156, 469-477

Fojt W, Harding M (1995) Thirty years of change in the vegetation communities of three valley mires in Suffolk, England. Journal of Applied Ecology 32(3), 561-577

Gerard M, El Kahloun M, Mertens, W, Verghagen B, Meire P (2008) Impact of flooding on potential and realised grassland species richness. Plant Ecology 194, 85-98

Guswell S (2005) High nitrogen: phosphorous ratios reduce nutrient retention and second-year growth of wetland sedges. New Phytologist 166, 537-550

Jermy AC, Turin TG (1968) British Sedges: Handbook to the species of Carex found growing in the British Isles. Botanical Society of the British Isles, London.

Kabucis I, Rusina S, Veen P (2003) Grasslands of Latvia. Latvian Fund for Nature. Available at http://www.veenecology.nl/data/Latvia.PDF (verified 19 May 2008)

Kleijn D, Berendse F, Smit R, Gilissen N, Smit J, Brak B, Groeneveld R (2004) Ecological effectiveness of agri-environment schemes in different agricultural landscapes in The Netherlands. Conservation Biology 18(3), 775-786

Kleyer M, Poschlod P (2004) Habitat models for plant functional groups with respect to soil parameters and management. Olenburg. Available at deposit.ddb.de/cgi-bin/dokserv?idn=974181900&dok_var=d1&dok_ext=pdf&filename=974181900.pdf (verified 30 May 2008)

Kukkonen I, Toivonen H (1988) Taxonomy of Wetland Carices. Aquatic Botany 30, 5-22

Hoffman M, Cosyns E, Lamoot I (2005) Large herbivores in coastal dune management: do grazers do what they are supposed to do? In: Herrier JL, Mees J,

Luoto M, Pykälä J, Kuussaari M (2003) Decline of landscape-scale habitat and species diversity after the end of cattle grazing. Journal for Nature Conservation 11, 171-178

Office of the Great Lakes (OGL) Michigan Department of Environmental Quality (2000) Lake Huron Initiative Nonindigenous Species Action Plan. Available at http://www.deq.state.mi.us/lhi/huron/LHexotics.html (verified 29 May 2008)

Preston CD, Hill MO (1997) The geographical relationships of British and Irish vascular plants. Botanical Journal of the Linnean Society 124, 1-20

Regnell G (1980) A numerical study of successions in an abandoned, damp calcareous meadow in S Sweden. Vetetatio 43, 123-130

Reznicek AA, Catling PM (2002) In: Flora of North America Editorial Committee. Flora of North America, north of Mexico, Vol 23: Magnoliophyta: Commelinidae (in part): Cyperaceae, Oxford University Press

Salman A, Seys J, Van Nieuwenhuyse H, Dobbelaere I (Eds) Proceedings ‘Dunes and Estuaries 2005’ – International Conference on Nature Restoration, Practices in European Coastal Habitats, Koksijde, Belgium, 19-23 September 2005, p. 249-267. VLIZ Special Publication 19, xiv + 685 pp. Available at http://www.vliz.be/imis/imis.php?module=ref&refid=76367 (verified 19 May 2008)

Schutz W (2000) Ecology of seed dormancy and germination in sedges (Carex). Perspectives in Plant Ecology, Evolution and Systematics 3(1), 67-89

Skytte Christiansen M (1979) Grasses, sedges and rushes in colour. Blandford Press, Poole, Dorset.

Symoens JJ (ed) (1988) Handbook of Vegetation Science; Vol 15/1 Vegetation of inland waters. Kluwer Academic Publishers, Dordrecht, Boston, London.

Tyler G (1971) Hydrology and Salinity of Baltic Sea-Shore Meadows: Studies in the Ecology of Baltic Sea-Shore Meadows III. Oikos 22(1), 1-20

Zvereva GA (1990) Analysis of the structure of salt-tolerant plant communities of the Barabinsk forest steppe. Soviet Journal of Ecology 21(6), 295-303

Global present distribution data references

Australian National Herbarium (ANH) (2008) Australia’s Virtual Herbarium, Australian National Herbarium, Centre for Plant Diversity and Research, Available at http://www.anbg.gov.au/avh/ (verified 23 May 2008).

Department of Sustainability and Environment (DSE) (2006) Flora information system [CD-ROM], Biodiversity and Natural Resources Section, Viridans Pty Ltd, Bentleigh.

Global Biodiversity Information Facility (GBIF) (2008) Global biodiversity information facility, Available at http://www.gbif.org/ (verified 23 May 2008).

Missouri Botanical Gardens (MBG) (2008) w³TROPICOS, Missouri Botanical Gardens Database, Available at http://mobot.mobot.org/W3T/Search/vast.html (viewed 23 May 2008).

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