T. domingensis can spread prolifically by rhizomes after seedlings establish in disturbed vegetation, often forming monotypes that reduce wetland plant and animal diversity. The species thrives under eutro...
Typha domingensis; foreground with sparse Schoenoplectus americanus. Most Typha ramets are vegetative, although some flowering ramets are visible. June 2006, Michoacán, México.
Copyright
Steven J. Hall
Dense stand
Typha domingensis; foreground with sparse Schoenoplectus americanus. Most Typha ramets are vegetative, although some flowering ramets are visible. June 2006, Michoacán, México.
Steven J. Hall
Title
Flowering stand
Caption
Dense Typha domingensis. Some flowering ramets with pistillate spikes are visible. June 2006, Michoacán, México.
Copyright
Steven J. Hall
Flowering stand
Dense Typha domingensis. Some flowering ramets with pistillate spikes are visible. June 2006, Michoacán, México.
Steven J. Hall
Title
Flowering ramets
Caption
Typha domingensis in flower, as leaves begin to senesce. February 2008, Chiapas, México.
Copyright
Steven J. Hall
Flowering ramets
Typha domingensis in flower, as leaves begin to senesce. February 2008, Chiapas, México.
T. domingensis can spread prolifically by rhizomes after seedlings establish in disturbed vegetation, often forming monotypes that reduce wetland plant and animal diversity. The species thrives under eutrophic conditions and artificially stabilized hydroperiods, but in undisturbed, low-nutrient wetlands, T. domingensis often grows sparsely and does not appear to reduce diversity. T. domingensis is economically important in many regions as a weaving material, but when invasive, the species can replace other valuable plant commodities. Short-term Typha control is provided by cutting, burning, or grazing, each followed by flooding, or herbicide, but re-growth from rhizomes and a vast soil seed-bank complicate eradication.
Typha is a cosmopolitan genus of emergent wetland macrophytes, containing anywhere from 8-13 species, and requiring taxonomic revision (Smith, 1987). Typha spp. often hybridize, perpetuating taxonomic confusion. Smith (1987) suggests that the pan-tropical species Typhadomingensis Pers. should be treated in a broad sense, and should include the synonyms T. angustata Bory & Chaubard, T. australis K. Schum. & Thonner, T. brownii Kunth, T. javanica Schnizl., and T. grossheimii Pobed. In North America and Australia, T. domingensis has commonly been mis-identified as T. angustifolia (Finlayson et al., 1983; Smith, 1987). See Institute for Systematic Botany (2008) for a comprehensive list of synonyms. Common names often refer to multiple species within the genus. See Burkhill (2000) for an extensive list of West-African common names.
T. domingensis is a rhizomatous perennial emergent wetland macrophyte. Ramets (culms) range from 1-6 m tall (Denny, 1985b) and consist of numerous slender, linear, distichous leaves with a sheathing base that emerge vertically from a central meristem. Ramets often produce a single, erect, monoecious flowering stem consisting of a staminate spike above a pistillate spike. At maturity, ramets can collapse from wind, or under their own weight (S Hall, University of Wisconsin, USA, personal communication, 2008). Rhizomes often measure several centimeters in diameter and produce abundant adventitious roots. Smith (1967, 2000) distinguished T. domingensis from similar species primarily on the basis of pistillate spike characters. T. domingensis is characterized by: pistillate bracteoles pale to light brown, slightly exceeding pistil hairs in mature spikes; pistil hair apices colorless to orange; stigmas linear to lanceolate, slightly exceeding bracteoles in mature spikes; pistillate spikes at anthesis cinnamon to light-brown, darkening slightly at maturity; monad pollen; staminate bracteoles (scales) straw to orange-brown colored; mucilage glands present on the adaxial surface of leaf sheathes and adjacent blades. Leaves are 6-18 mm wide, mature pistillate spikes are 13-26 mm wide, and the pistillate and staminate spikes are separated by a gap of 0-8 cm. Some quantitative macroscopic characters including spike width, gap length between pistillate and staminate spikes, and leaf width are useful, but are too variable for conclusive identification, which depends on the above microscopic floral characteristics. Finlayson et al. (1985) combined measurements of the gap between male and female inflorescences with the length and diameter of the female inflorescences to distinguish T. domingensis from T. orientalis in Australia.
Plant Type
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Grass / sedge Herbaceous Perennial Seed propagated Vegetatively propagated
Because T. domingensis is sometimes confused with other species of Typha, especially T. angustifolia, and because numerous synonyms exist, adequately assessing its distribution is difficult. T. domingensis sensu lato inhabits wetlands in tropical, sub-tropical, and Mediterranean climates in the Americas, Eurasia, the Middle East, and Africa. The species is probably present in most of tropical and sub-tropical Africa (Thompson, 1985; CJBVG and CANBI, 2008), as well as most of the Caribbean, the Middle East, and some Pacific islands, but some countries lack accessible and comprehensive plant distribution data; the distribution table is a conservative and under-representative estimate. Chakraborty (1996) reports T. angustata (presumably T. domingensis) from northern India. In North America, T. domingensis inhabits both coasts and much of the southern United States, including arid zones of the Great Plains and Great Basin (Smith, 1967).
The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.
Few instances of long-distance introduction have been reported, but these could be obscured by taxonomic confusion. T. domingensis may be introduced in Hawaii (USDA, 2008). In many cases, Typha appears to have expanded locally within regions where it was already present as a result of anthropogenic habitat modification and/or cultural change (e.g. Finlayson et al., 1983; Beare and Zedler, 1987; Urban et al., 1993; Hall, 2008).
T. domingensis appears to occupy much of its potential habitat range worldwide, but as anthropogenic modification of tropical wetlands continues, it will continue to invade at the local and regional scale in habitats where stabilized, nutrient-rich, low-salinity water is present. Other aggressive Typha species (e.g. T. x glauca) are likely to be more problematic as invaders in temperate climates.
T. domingensis is present in many wetland community types, including marshes, groundwater-fed fens, shrub- carr, lakeshores, and estuaries, as well as anthropogenic habitats where soil is periodically flooded (roadside ditches, irrigation canals, fields, storm-water retention basins). Freshwater inflows allow T. domingensis to invade salt marshes (Beare and Zedler, 1987). T. domingensis is most dominant in wetlands with artificially prolonged hydroperiods and nutrient-rich water (Findlayson et. al, 1983; Beare and Zedler, 1987; Urban et al., 1993; Nicol and Ganf, 2000). T. domingensis grows on fine organic mud and silt, peat, and also sand and gravel (Finlayson et al., 1983), as well as on alkaline soil (Denny, 1985a).
T. domingensis readily hybridizes with other sympatric species of Typha. T. domingensis x latifolia has mostly abortive pollen and low seed set, while T. angustifolia x domingensis (reported in France and California) is highly fertile and can form hybrid swarms (Geze, 1912, cited in Smith, 1987; Smith, 1967). T. domingensis, T. latifolia, and T. angustifolia share n=15 chromosomes (Smith, 1967). T. domingensis shows ecotypic variation for a number of traits, including salt tolerance, germination temperature, time of flowering, height, rhizome proliferation, and rhizome number (McNaughton, 1966). Because of the worldwide distribution of T. domingensis, quantitative data presented here will likely vary widely among regional ecotypes.
Reproductive Biology
T. domingensis is protogynous, self-compatible, and does not show apomixis (Smith, 1967). Pollen requires strong winds for dispersal, and T. latifolia pollen can travel distances of at least one km (Krattinger, 1975). Despite copious pollen production, self-pollination appears to exceed outcrossing even in dense stands of T. latifolia . Some populations of T. domingensis remain in anthesis for more than a month (McNaughton, 1966). Each inflorescence can produce > 600,000 fruits, or 6-17 million seeds per m2 depending on flowering ramet density, and plants established from seed can flower by the second year (Prunster, 1940, cited in Finlayson et al., 1983; Howard-Williams, 1975). Germination can occur year-round in many climates, given adequate moisture, although germination declines below 20°C (Finlayson et al., 1983). In the United States, southern populations germinated at a lower temperature (13°C) than their northern counterparts (McNaughton, 1966). Seeds germinate under moist or submerged conditions; in an extreme case, T. domingensis germinated under 80 cm of water and survived for 8 weeks (Nicol and Ganf, 2000). Salinity reduces germination, although limited germination can occur even at 20% salinity (Beare and Zedler, 1987). High salinity prevented T. domingensis from recruiting after a lake drawdown in Malawi (Howard-Williams, 1975). Exposure to light and hypoxia increase germination (Sifton, 1959), which is low under established vegetation (Finlayson et al., 1983). In natural areas not disturbed by humans, disturbance and herbivory by animals could facilitate seedling establishment of Typha seedlings (Svengsouk and Mitsch, 2001).
Lateral rhizomes can facilitate rapid vegetative expansion after seedling establishment. Individual T. latifolia clones can span >60 m (Krattinger, 1983), and T. domingensis can spread laterally at 3-10 m/year (Parsons and Cutherbertson, 1992; Fraga and Kvet, 1993). Rhizome production is stimulated by short days and cold temperatures (McNaughton, 1966).
Physiology and Phenology
In frost-free climates, T. domingensis can produce ramets (culms) year-round, although most emerge in summer and autumn, and do not survive longer than 10 months (Finlayson et al., 1983; Parsons and Cuthbertson, 1992). In a spring-fed wetland in central Mexico, T. domingensis growing in dense stands did not produce new ramets between May and October unless disturbed by leaf harvest (Hall et al., in press). Flowering ramets differentiate by spring, and become fertile by early summer. Grace and Harrison (1986) contend that high rhizome carbohydrate supplies promote Typha ramets to flower rather than to remain vegetative. Repetitive harvesting decreased rhizome starch reserves and flowering ramet density of T. domingensis, but drought stress could promote flowering (Hall, 2008). Carbohydrate dynamics have been studied for T. latifolia. Leaf biomass is at a maximum while rhizome biomass is minimized in late summer. By autumn, leaf carbohydrates have been translocated to rhizomes, biomass increases, and rhizome starch concentrations are maximized (Linde et al., 1976). For T. domingensis in Belize, leaf turnover averages 110 days (Rejmankova et al., 1996). Fraga and Kvet (1993) report that T. domingensis in Cuba had a net primary productivity of 1500 g/m2/year. Litterbag experiments showed only 50% decomposition after one year, and organic matter accumulated rapidly.
In flooded conditions, oxygen is conducted to Typha’s underwater tissues via leaf aerenchyma cells (Sale and Wetzel, 1983), allowing T. domingensis to tolerate water 2 m deep (Finlayson et al., 1983). Flooded seedlings only produced additional ramets, however, when they reached the water surface (Nicol and Ganf 2000). T. domingensis is moderately salt-tolerant, and salinities of up to 5% should not impede vegetative growth or flowering. Salinity >5% prevents growth, and salinity >25% causes leaf mortality, although rhizomes re-sprout if salinity declines (Beare and Zedler, 1987). Freshwater inflows lasting 2 months allowed T. domingensis to invade California salt marshes. T. domingensis thrives in hot climates, and grows well in water at 30°C (Finlayson et al., 1983). Parsons and Cuthbertson (1992) reported maximum growth at 32°C, declining to 50% at 18°C. Typha spp. show a high tolerance for soil and water contaminated by heavy metals (McNaughton et al., 1974).
Nutrition
T. domingensis thrives under high nutrient loads and stable, prolonged, hydroperiods. In the Florida Everglades, T. domingensis invasion correlated with increased phosphorus and water levels, and muck-burning fires (Urban et al., 1993; Newman et al., 1998). Typha’s limitation by phosphorus is supported by a comparison of soil and plant tissue samples from eutrophic and un-impacted areas of the Everglades (Koch and Reddy, 1992). T. domingensis also appeared limited by phosphorus in wetlands of Mexico’s Yucatan Peninsula and Belize (Rejmankova et al., 1996). In mesocosms, elevated nutrient levels and prolonged hydroperiods increased T. domingensis biomass and tissue phosphorus concentration relative to the co-occurring Cladium jamaicense (Newman et al., 1996). Substantial peat, nitrogen, and phosphorus accumulated where T. domingensis dominated nutrient-rich areas of the Everglades (Craft and Richardson, 1993). Seedlings produced more biomass, had a greater root/shoot ratio, and contained more phosphorous when grown in burned soil than in unburned or surface-burned soil in the Everglades, suggesting that soil-burning fires promote T. domingensis by releasing phosphorus (Smith and Newman, 2001). In low-nutrient areas of the Everglades, Typha is present but does not dominate (Davis, 1994).
Nitrogen and phosphorus appeared to co-limit the congener T. latifolia when it was grown in mesocosms, whereas in the field, T. latifolia increased along a gradient of increasing phosphorus (Svengsouk and Mitsch, 2001). T. x glauca required both nitrogen and phosphorus for growth in a greenhouse experiment, but adding a higher proportion of phosphorus stimulated growth regardless of nutrient concentration (Woo and Zedler, 2002).
Associations
In disturbed and eutrophic wetlands, T. domingensis tends to form monotypes. However, T. x glauca’s invasive growth may be dependent on anthropogenic modifications (e.g. from dams, wastewater discharge, or irrigation canals). In little-disturbed wetlands where hydroperiods fluctuate seasonally, many genera co-occur with T. domingensis. In Australian wetlands, Baumea, Eleocharis, Gahnia, Melaleuca, Muehlenbeckia, and T. orientalis co-dominate with T. domingensis where water levels fluctuate (Finlayson et al., 1983; Nicol and Ganf, 2000). In Cuba, Bidens, Cyperus, Eleocharis, Hyparrenia, Panicum, and Sagittaria can co-occur with T. domingensis in shallow water, although T. domingensis often forms temporary monotypes in deeper water (Fraga and Kvet 1993). In this system, shrubs can replace Typha because of rapid organic matter accumulation; frequent fire might reduce litter and retard succession. In Africa’s Lake Victoria, T. domingensis is less abundant than the dominant Cyperus or Miscanthidium (Kansiime et al., 2007); in Lake Chad, Vossia, Cyperus, and Phragmites dominate, while T. domingensis is rare (Denny, 1985a). Thompson (1985) ranked T. domingensis as the third most-dominant African wetland plants, behind Phragmites australis and P. mauritianus. In Belize, T. domingensis normally dominates on clay soils with low salinity, while growing sparsely with dominant Eleocharis and Cladium on marl and sandy soil with higher salinity (Rejmankova et al., 1996). T. domingensis monotypes in this region may be relics of phosphorus-rich agricultural run-off. In Iran, T. domingensis and Schoenoplectus tabernaemontani co-dominate diverse wetlands (Karami et al., 2001). In a groundwater-fed wetland in central Mexico, harvesting T. domingensis increased species richness and the recruitment of uncommon species (Hall, 2008). Here, more than 40 species co-occurred with Typha and the co-dominant Schoenoplectus americanus.
Environmental Requirements
T. domingensis tolerates a broad climatic spectrum, growing between 40° latitude north and south under a variety of rainfall regimes (Smith, 2000). Although T. domingensis tolerates widely variable hydroperiods, it can decline during extended drawdowns, and grows best under flooded conditions (Rejmankova et al., 1996; Palma-Silva et al., 2005). Rainfall does not appear to limit wide-scale geographic distribution, because even in seasonally dry climates (e.g. central Mexico), T. domingensis can persist in isolated springs or on lakeshores. Seedlings can tolerate anaerobic conditions, but mature plants are intolerant of anaerobic conditions created when leaves are severed below water (Sale and Wetzel, 1983).
Herbivory is common but variable. In Australia, kangaroos, rodents, and water birds lightly graze T. domingensis, while water buffalo can cause heavy damage (Finlayson et al., 1983). In Africa, large herbivores do not extensively feed on T. domingensis, despite its abundance (Howard-Williams and Gaudet 1985). In Costa Rica and elsewhere throughout Latin America, cattle heavily graze T. domingensis (McCoy et al., 1994). Muskrats (Ondatra zibethicus) can eliminate entire stands of Typha spp. through herbivory, at least in temperate climates (Kadlec et al., 2007). Barreto et al. (2000) mention a variety of fungal pathogens, although none have been extensively studied in the field. A variety of insects feed on T. latifolia and T. angustifolia. Lepidopteran larvae often inhabit inflorescences, while noctuid caterpillars and coleoptera attack leaves, stalks, and sometimes rhizomes (Grace and Harrison, 1986).
Typha’s tiny seeds (1 - 2 mm long) are contained in achenes attached to pistil hairs, and are often dispersed by the wind. Spikes do not shed fruits until they have dried (Krattinger, 1975), often delaying dispersal until many months after seed maturation. The entire female spike sometimes collapses in place, providing a floating platform for germination (Hall, 2008). Masses of achenes and hairs, and rhizomes, can disperse by floating on currents of water (Grace and Harrison 1986; Parsons and Cutherbertson, 1992).
Vector Transmission (Biotic)
When achenes are moistened, seeds are released, which have a pointed end that can become embedded in fish scales (Krattinger, 1975). Also, pistil hairs (with attached acenes) adhere to the clothing of fieldworkers, and could attach to animals as well (S Hall, University of Wisconsin, USA, personal communication, 2008). Mud with embedded seeds readily sticks to humans, livestock, birds, and agricultural implements (Parsons and Cuthbertson, 1992).
Intentional Introduction
Indigenous people in the Northwestern United States propagated T. latifolia using rhizome fragments (Turner and Peacock, 2005). Similar propagation of T. domingensis has not been documented.
T. domingensis can interfere with agriculture in wet areas. With the adoption of year-round rice cropping in Australia, T. domingensis invaded fields and decreased yields by 5% (Sykes 1981, cited in Finlayson et al., 1983). In central Mexico’s Lake Pátzcuaro, T. domingensis can invade low-lying cornfields. This species also tends to replace the bulrush Schoenoplectus californicus, a valuable species traditionally used to weave mats (Hall, 2008). In southern Mexico, T. domingensis invades wetlands used for horse pasture, and replaces valuable fodder (S Hall, University of Wisconsin, USA, personal communication, 2009). In lacustrine wetlands, T. domingensis can interfere with fishing and water transportation (Mitchell, 1985).
In arid climates, Typha spp. can deplete water supplies through excessive evapotranspiration (Morton, 1975). T. domingensis increased evapotranspiration by 65% relative to open water (Brezny et al., 1973). Alternatively, dense T. domingensis monotypes can retard water flow through drainage canals, causing flooding and siltation (Findlayson et al., 1983; Parson and Cuthbertson, 1992). The congener T. x glauca appears to alter soil microbial community structure relative to the plants it replaces, leading to increased nitrogen and phosphorus concentrations and lower water quality (Angeloni et al., 2006). In the Florida Everglades, T. domingensis doubled gaseous mercury production relative to Cladium jamaicense (Lindberg et al., 2002).
Impact on Biodiversity
Dense T. domingensis monotypes can decrease the abundance of many waterfowl species by decreasing open water habitat (McCoy et al., 1994; Smith and Breininger, 1995), although some bird species breed in Typha monotypes (Shy et al., 1998). Quantitative effects of T. domingensis on species richness are less documented but richness declined precipitously when cover of the congener T. x glauca cover increased in wetlands of the Midwestern United States (Frieswyk and Zedler, 2006; Boers et al., 2007).
Typha invasion can reduce opportunities for waterfowl hunting and viewing, and decrease the aesthetic value of natural areas by lowering biodiversity, for example, in Costa Rica’s Palo Verde National Park (McCoy et al., 1994).
T. domingensis leaves are used for weaving in many cultures (Morton, 1975). In central Mexico, an armful of leaves sold for US $1-3 in July 2007 (Hall, 2008). T. domingensis produces a toxic oil, so its starch-filled rhizomes are inedible, but protein-rich pollen is a valuable food in some regions (Morton, 1975).
Social Benefit
T. domingensis could provide valuable raw materials, protein, wastewater treatment, fertilizer (when burned), and industrial-site remediation.
Environmental Services
When growing sparsely, T. domingensis provides cover for wildlife and reduces channel erosion (Parsons and Cuthbertson, 1992). In Israel, T. domingensis monotypes provided nesting sites for egrets and herons (Shy et al., 1998). Typha might be most appropriate for remediating industrial sites, because of a generally high tolerance for heavy metals (McNaughton et al., 1974). Natural and artificial wetlands dominated by T. domingensis reduced sulfates and heavy metals in outflow water from mine tailings (Noller et al., 1994). T. domingensis has been used in wastewater treatment wetlands, but its functional superiority to other wetland species is unclear. T. domingensis reduced chemical oxygen demand of pulp mill wastewater in Kenya (Abira et al., 2003). Treatment wetlands, however, are easily overloaded (Finlayson et al., 1987), and concentrated effluent from feedlots can be toxic to T. domingensis (Bowmer, 1985).
T. domingensis often grows with T. latifolia, T. angustifolia, T. orientalis. Floral characters of these species, summarized from Smith (1967, 2000), are described below. See Smith (2000) for descriptions of hybrids.
T. latifolia is characterized by: absence of pistillate bracteoles; broad stigmas (ovate to lanceolate); compound pedicels long, soft, and slender (1.5-3.5 mm), visible after flowers are removed from the spike axis; pistillate spikes green at anthesis, black at maturity; pistil hairs linear, colorless; staminate bracteoles colorless; tetrad pollen. Pistillate and staminate spikes are normally contiguous, and mature pistillate spikes (24-36 mm) and leaves (10-29 mm) are wider than in other species.
T. angustifolia shares many characters with T. domingensis (compound pedicels short and stiff, stigmas linear, pistillate bracteoles present, monad pollen), but is distinguished by: pistillate bracteoles dark to medium brown; pistil hairs brown, with enlarged apices, equaling or exceeding bracteoles; pistillate spikes dark brown; staminate bracteoles brown, sometimes bifid; absence of mucilage glands from adaxial leaf sheath surfaces. Pistillate and staminate spikes are normally separated by a gap of 1-12 cm, mature pistillate spikes are 10-22 mm wide, and leaves are 4-14 mm wide.
T. x glauca has characters intermediate to its parents, T. angustifolia and T. latifolia: pistillate bracteoles slender, brown-colorless, difficult to distinguish from pistil hairs; pistil hair apices colorless, sometimes with an apical brown cell; narrow, apparently linear stigmas; monad, diad, triad, or tetrad pollen. Compound pedicles (0.7-1.3 mm long) leaves (5-19- mm wide), mature pistillate spikes (14-27 mm wide) and the spike gap (4-33 mm long) are all intermediate in measurement to the parental species.
T. orientalis is found in Australia, and is characterized by: few, narrowly-spathulate pistillate bracteoles; narrow to obovate stigmas. Compared to T. domingensis, females spikes are generally wider (10-30 mm), have a shorter length to width ratio (5-10 times long as wide), have a shorter spike gap (0-20 mm), and leaves often have a darker blue colour (Finlayson et al., 1983, 1985).
Prevention is difficult given Typha’s prolific seed production and rhizome expansion. Reducing anthropogenic disturbance of soil and vegetation could reduce establishment, but disturbance by animals can still create germination sites, even in protected wetlands. Maintaining natural hydrology, salinity, and nutrient levels could reduce the density and spread of Typha after it establishes. Maintaining consistently high water levels (> 1.2 m) in managed wetlands could prevent establishment from seed (Ivens, 1967).
Eradication
Seed banks of the congener T. x glauca often contain hundreds of viable seeds/m2 (van der Valk and Davis, 1978). Eradication of T. domingensis would require yearly surveillance to kill new clones as they establish.
Control
Physical/mechanical control
Burning, cutting, and grazing often reduce Typha spp. when followed by flooding. These methods remove leaf tissue that Typha requires to transport oxygen to underwater rhizomes. Deprived of oxygen, Typha respires anaerobically and accumulates ethanol as a toxic byproduct, causing mortality (Sale and Wetzel, 1983). High water levels are necessary to maintain Typha in an anaerobic environment after it re-sprouts. Water depths sufficient for complete mortality of Typha spp. after cutting have ranged from 26-80 cm, and experiments where water levels varied spatially showed increased re-growth in shallow water relative to deeper water (Shekhov, 1974; Beule and Hine, 1979; Murkin and Ward, 1980; Mallik and Wein, 1985; Ball, 1990). Cutting Typha while ramets are flowering and rhizome carbohydrate reserves are low reduces re-growth (Linde et al., 1976; Singh et al., 1976). Fires in flooded wetlands do not normally reduce Typha, probably because underwater leaf tissue is not damaged (Mallik and Wein, 1985; Grieco et al., 2005; Lee et al., 2005). In drained wetlands, fire can sometimes reduce Typha by damaging rhizomes directly (Mallik and Wein, 1985). Soil-burning fires can benefit Typha by increasing nutrient availability (Newman et al., 1998; Smith and Newman, 2001), but post-fire nutrient pulses might only increase growth temporarily (Ponzio et al., 2004). Successive water-level drawdowns could favor sedges (e.g. Eleocharis spp.) over Typha (Palma-Silva et al., 2005). Draining and bulldozing provides destructive but effective control (Parsons and Cuthbertson, 1992). Sheep grazing decreased T. domingensis density in the soil seed bank (Nicol et al., 2007).
Biological control
Muskrats can decimate Typha spp. in temperate areas (Kadlec et al., 2007), and in Utah, herbivory by waterfowl and muskrats on Typha spp. appeared to increase following fire (Smith and Kadlec, 1985).
Chemical control
Herbicides can reduce Typha in the short-term, including glyphosate, amitrole-T, amino-triazole, TCA, 2,2-DPA, or MCPA (Finlayson et al., 1983; Annen, 2007). These are effectively applied during flowering or when leaves begin to senesce.
Control by utilization
Harvesting Typha leaves can reduce re-growth, if followed by flooding.
Monitoring and Surveillance
Dense T. domingensis monotypes are visible on aerial photos and their expansion can be tracked over time (Urban et al., 1993).
Ecosystem Restoration
Restoring natural hydrology, preventing prolonged flooding, and reducing nutrient loads should minimize Typha’s spread and ameliorate effects on diversity. A multi-billion dollar engineering effort aims to restore natural hydroperiods to the Florida Everglades (Sklar et al., 2005).
