Water and Rivers Commission WN20 July 2000 t Natural Heritage Trust tes for re ano ive ater rs mr WW anagementnotes GOVERNMENT OF WESTERN AUSTRALIA ADVISORY NOTES FOR LAND MANAGERS ON RIVER AND WETLAND RESTORATION Rushes and sedges Rushes and sedges are terms commonly When planted in dense stands, native rushes and sedges are applied to species from the grass-like excellent for weed control, excluding less desirable species and out-competing others. This is particularly important in families Juncaceae, Restionaceae and the wheatbelt where many saline watercourses are being Cyperaceae. While occurring in a wide colonised by the exotic spiny rush, Juncus acutus. This range of habitats, from estuarine to desert, species should be replaced with appropriate native rushes and sedges are particularly analogues, such as Juncus kraussii and Gahnia trifida. A list of suitable species for planting in a wide range of important in wetlands. Unlike many tree conditions is given in Table 1. and shrub species, they have shallow spreading surface roots, which bind the soil and reduce erosion. Erosion is one of the major constraints to successful river Juncus kraussii (Sea rush). restoration. Rushes and sedges are also pivotal to water quality improvement of wetlands. Their soil binding properties and growth habit means they are excellent at slowing the rate of water flow and trapping sediment within waterways. Dense stands of rushes and sedges planted along the foreshore or buffer areas of a wetland also trap soil and water run-off from adjacent land, which in turn limits the export of nutrients into waterbodies. Many species further improve water quality by acting as ‘nutrient-strippers’, accumulating significant amounts of nutrients in stems and rhizomes (underground stems), and supporting bacterial transformation of nutrients and other pollutants on their extensive root and rhizome mass. The root systems of many species also help to oxygenate the water and sediment by ‘leaking’ excess oxygen through their roots. This is important for nutrient transformation and for providing microhabitat for invertebrate fauna. The dense structural habit of rushes and sedges is also important as a habitat refuge for native invertebrate and vertebrate fauna, such as Christmas spiders and little grass birds which are important mosquito predators. Gahnia trifida (Coast saw-sedge). Figure 1: Beard’s Natural Regions. Natural Regions Code Phytogeographic Districts Avon Wheatbelt Av Avon Botanical District Coolgardie Co Coolgardie Botanical District Esperance Ey Eyre Botanical District Geraldton Sandplain Ir Irwin Botanical District Jarrah Forest Dl/Me Dale/Menzies Sub Districts Mallee Ro Roe Botanical District Swan Coastal Plain Du Drummond Sub District Warren Wa Warren Sub District lr N Du Av INDIAN Co OCEAN Dl Ro Ey Me Wa Table 1. Common sedges and rushes of south-west wetlands. Species River1 Creek1 Floodplain1 Wetland Soil Water Salt- Availability3 Distribution Type Depth tolerance2 (See Figure 1) 1 1 1 1 Lake Channel Channel Palusplain Floodplain Sumpland Dampland C = clay P = peat S = sand Embankment F = fresh B = brackish S = saline Av = Avon = Av Ir = Irwin etc Seasonally wet Seasonally wet Seasonally wet S = seed P = plants C = contract grown NA = not available Embankment Permanently inundated Permanently inundated Seasonally inundated flat Seasonally inundated basin Seasonally waterlogged flat DW = deep water (0.5-1m) SW = shallow water (<0.5m) = permanently wet PWe = seasonally wet SWe Seasonally waterlogged basin Sedges Baumea articulata ✔✔✔ C, P, S DW, SW, PWe F, B P Du, Dl, Me, Wa, Av, Ro, Ey Baumea juncea ✔✔✔ ✔ ✔ ✔ ✔ ✔ C, P, S SW, PWe, SWe F, B P Ir, Du, Dl, Me, Wa, Av, Ro, Ey, Co Baumea preissii ✔✔ P, S SW, PWe, SWe F, B P Du, Dl, Me, Wa Baumea rubiginosa ✔✔C, P, S SW, PWe, SWe F P Du, Dl, Me, Wa Baumea vaginalis ✔✔✔ C, P, S SW, PWe, SWe F, B P Du, Dl, Me, Wa Carex appressa ✔✔ C, P, S PWe, SWe F P Du, Dl, Me, Wa Carex fascicularis ✔✔✔ ✔ C, P, S SW, PWe, SWe F P Du, Me, Wa Carex tereticaulis ✔✔C, S PWe, SWe F P Du, Dl Chorizandra enodis ✔✔ ✔✔ C, S SW, PWe, SWe F, B C Ir, Du, Dl, Av, Co, Ro, Ey, Me, Wa Cyperus gymnocaulos ✔✔ P, S PWe F, B NA Du, Ir Eleocharis acuta ✔✔✔C, S SW, PWe, SWe F, B, S P Du, Ir, Dl, Me, Av, Ro, Ey, Co Evandra pauciflora ✔✔✔S PWe, SWe F NA Du, Me, Wa Evandra aristata ✔✔✔S, P PWe, SWe F NA Me, Wa Gahnia decomposita ✔✔✔P, S PWe, SWe F, B NA Du, Dl, Me, Wa, Ey Gahnia trifida ✔✔✔✔ C, P, S PWe, SWe F, B, S P Ir, Du, Dl, Me, Wa, Av, Co, Ro, Ey Isolepis nodosa ✔✔✔✔ P, S PWe, SWe F, B, S S, P Ir, Du, Dl, Me, Wa, Av, Co, Ro, Ey Lepidosperma effusum ✔✔ ✔ C, S SWe, PWe F P Du, Me, Wa Lepidosperma gladiatum ✔✔ ✔✔✔ C, P, S PWe, SWe F P Ir, Du, , Me, Wa, Ey Lepidosperma longitudinale ✔✔✔✔✔P, S PWe, SWe F NA Du, Dl, Me, Ey Lepidosperma tetraquetrum ✔✔✔ C, P, S SW, PWe, SWe F P Du, Dl, Me, Wa Schoenoplectus pungens ✔✔ C, P, S SW, PWe F P Du, Me, Wa Schoenoplectus validus ✔✔ ✔ ✔ C, P, S DW, SW F, B, S S, P Du, Me Schoenus subfasciculatus ✔✔✔C, P, S PWe, SWe F NA Du, Me, Wa, Ey, Dl Rushes Juncus holoschoenus ✔✔✔C, P, S SWe, PWe F P Du, Dl, Me Juncus kraussii ✔✔✔C, P, S SW, PWe B, S S, P Ir, Du, Me, Wa, Dl, Av, Co, Ro, Ey Juncus pallidus ✔✔✔✔✔✔ C, P, S PWe, SWe F, B S, P Du, Dl, Me, Wa, Ey, Av Juncus pauciflorus ✔✔ C, P, S PWe, SWe F P Du, Me, Wa Juncus subsecundus ✔✔ ✔✔ C, P, S PWe, SWe F, B P Du, Dl, Me, Wa, Ey, Ro, Co, Av Southern Rushes Anarthria prolifera ✔✔✔ P, S PWe, SWe F C Du, Dl, Me, Wa, Ey Anarthria scabra ✔✔ ✔✔✔P, S PWe, SWe F NA Me, Wa, Ey Chaetanthus aristatus ✔✔✔P, S SW, PWe, SWe F C Ir, Du, Me, Wa, Ey Dielsia stenostachyus ✔✔✔✔ P, S PWe, SWe F C Du Empodisma gracillimum ✔✔✔ ✔✔✔C, P, S SW, PWe F, B NA Du, Me, Wa Hopkinsia anoectocolea ✔✔ S SW, PWe, SWe F, B, S P Ir, Av, Ro, Ey Hypolaena exsulca ✔✔ ✔ ✔✔P, S SW, PWe, SWe F P Ir, Du, Dl, Av, Me, Wa, Ey, Ro Hypolaena fastigiata ✔✔P, S PWe, SWe F C Du, Me, Wa, Ey, Ro Hypolaena pubescens ✔✔ ✔✔✔P, S PWe, SWe F C Du, Dl, Me, Wa, Av, Ey Hypolaena rudis ✔✔P, S PWe, SWe F C Me, Wa Leptocarpus diffusus ✔✔ ✔ ✔ ✔ P, S SW, PWe, SWe F P Du, Me, Wa Leptocarpus tenax ✔✔ ✔✔✔C, P, S SW, PWe, SWe F P Du, Dl, Me, Wa, Ey Lepyrodia glauca ✔✔ ✔ ✔ C, P, S SW, PWe, SWe F, B NA Du, Av, Dl, Me Lepyrodia riparia ✔✔✔ C, S PWe, SWe F NA Du, Dl Loxocarya cinerea ✔✔✔ C, S SWe F NA Du, Dl, Av, Me, Wa Meeboldina canus ✔✔ ✔ ✔ ✔ C, P, S PWe, SWe F C Du, Dl, Me, Wa, Ey Meeboldina coangustatus ✔✔✔ ✔ ✔ C, P, S PWe, SWe F NA Du, Dl, Me Meeboldina roycei ✔✔✔ ✔ ✔ C, P, S SW, PWe, SWe F NA Du, Dl, Me, Wa, Ey Meeboldina scariosus ✔✔✔ ✔✔✔P, S SW, PWe, SWe F P Du, Me, Wa Melanostachya ustulatus ✔✔ ✔ ✔ ✔ P, S PWe, SWe F P Du, Me, Wa Taraxis grossa ✔✔✔ ✔ C, P, S SW, PWe, SWe F NA Du, Me, Wa Grasses Hemarthria uncinata ✔✔✔ ✔ C, S PWe, SWe, SW B, S NA Ir, Du, Dl, Av, Co, Ro, Me, Wa, Ey Microleana stipoides ✔✔✔ C, S PWe, SWe F C, P Du, Dl, Me, Wa, Ey Spartachloa scirpoidea ✔✔✔ C, S PWe, SWe, SW F, B C Dl, Av, Ro, Co, Ey Sporobolus virginicus ✔✔✔ C, P, S PWe, SWe, SW F, B, S C Ir, Du, Dl, Av, Me, Wa, Ey, Ro, Co 1 After Semeniuk 1997. River = permanently inundated channel; Creek = seasonally inundated channel; Dampland = seasonally waterlogged basin; Sumpland = seasonally inundated basin; Lake = permanently inundated basin; Floodplain = seasonally inundated flat; Palusplain = seasonally waterlogged flat. 2 Fresh = <1000 mg/L TDS; Brackish/Subhaline = 1000 – 3000 mg/L TDS; Saline = 3000 – 20 000 mg/L TDS. 3 Seed = available from commercial seed collectors & easy to propagate from seed; Plant = tubestock &/or barerooted plants available from commercial wetland nurseries; Contract grown = available on a 6 - 12 month pre-order basis from selected nurseries. Establishing rushes and sedges Propagation Site examination and preparation Propagation of many rushes and sedges from seed is very difficult and many require advanced tissue culture As with any revegetation program, areas to be planted or techniques. However, seed propagation is an easy method seeded must first be cleared of weeds. Species used should for Juncus spp., which produce massive amounts of small be selected according to the following criteria: seeds within papery capsules. Seeding heads should be 1.indigenous to the area; collected and dried, and the seeds shaken into storage 2.suitable for each specific wetland zone (e.g. channel containers or directly onto the surface of a basic seed bed, bank or upland); and propagation mix. Seeds germinate best in full light in warm conditions. 3.suitable for current and future conditions, which may have changed substantially from the historical Some of the sedges, which have nuts instead of capsules, hydrologic/nutrient/salinity pattern. can also be readily germinated. Carex, Schoenoplectus and Cyperus species produce abundant seed which will When to plant germinate if sown in high temperature conditions (>26˚C). Rushes and sedges should be planted in permanently wet or Many species propagate very well by vegetative division. moist areas in spring and summer during their peak growth Plants can be easily split into individual plantlets (known phase.