Does sulphate enrichment promote the expansion of Typha domingensis (cattail) in the Florida Everglades?¹

Abstract

1. The expansion of Typha domingensis into areas once dominated by Cladium jamaicense in the Florida Everglades has been attributed to altered hydrology and phosphorus enrichment, although increased concentrations of sulphate and phosphorus often coincide. The potential importance of hydrogen sulphide produced from sulphate in the expansion of Typha has received little attention. The present study aimed to quantify the comparative growth and photosynthetic responses of Cladium and Typha to sulphate ⁄ sulphide. 2. Laboratory experiments showed that Cladium is less tolerant of sulphide than Typha. Cladium was adversely affected at sulphide concentrations of approximately 0.22 mM M , while Typha continued to grow well and appeared healthy up to 0.69 mM M sulphide. 3. Experiments in field mesocosms provided strong support for species-specific differences in physiology and growth. Regardless of interstitial sulphide concentrations attained, Typha grew faster and had a higher photosynthetic capacity than Cladium. However, sulphide concentrations in the mesocosms reached only 0.18 mM M which, based on the hydroponic study, was insufficient to affect the growth or photosynthetic responses of either species. Nevertheless, the upper range of sulphide (0.25-0.375 mM M ) in Everglades' soil is high enough, based on our results, to impact Cladium but not Typha. 4. This research supports the hypothesis that sulphide accumulation could affect plant species differentially and modify species composition. Consequently, the role of sulphate loading should be considered, in conjunction with hydroperiod, phosphorus availability and disturbances, in developing future management plans for the Everglades.

Sulfur in the South Florida Ecosystem: Distribution, Sources, Biogeochemistry, Impacts, and Management for Restoration

“…These locations are also heavily enriched with phosphorus from agricultural runoff, and eutrophication has been suggested as the principal cause of this change in macrophyte dominance (Childers et al, 2003;Miao et al, 2000). Sulfide toxicity may also play a role, however, because the observed sulfide levels can exceed those toxic to Cladium (Li et al, 2009). The effects of sulfide on other Everglades flora are not known.…”

“…Li et al (2009) demonstrated that sulfide impacts Cladium at 7,480 µg l −1 in soil pore water. This level of sulfide occurs in areas where surface water sulfate concentrations routinely exceed 40 mg l −1 (<5% of the Everglades; Scheidt and Kalla, 2007).…”

“…The freshwater macrophyte Nitella flexilis shows toxic effects at sulfide levels as low as 1700 µg l −1 (Van der Welle et al, 2006), while Phragmites australis shows sulfide toxicity at levels of 6,800-10,200 µg l −1 (Hotes et al, 2005). In a greenhouse experiment, Li et al (2009) . At locations in the Everglades where Typha has displaced Cladium, pore water levels of sulfide approach 13000 µg l −1 (Gilmour et al, 2007b).…”

Anatomy and physiology of Cattail as related to different population densities

“…This is an emergent macrophyte commonly called cattail which leaves are amphistomatic with sclerenchymatous fibers forming groups between the palisade and spongy parenchyma (Henry, 2003). Cattail species may cause many problems colonizing non-native environments, for example, Li et al (2009) described the problem involving T. domingensis colonization reducing Cladium jamaicense populations in the Everglades. However, despite of some spots show high colonization of T. domingensis, occupying more than 50% of the area, in some spots plants do not colonize even 50% of its area.…”

Anatomical traits related to stress in high density populations of Typha angustifolia L. (Typhaceae)

“…This population behavior may damage hydroelectric energy production, river traffic, agricultural irrigation and nautical sports practice (Thomaz, 2002). Cattail population growth, in special, may decrease the size of other macrophyte population, as reported to Cladium jamaicense by Li et al (2009) and Eleocharis spp. by Macek et al (2010).…”