Changes in nutrient availability from calcareous to acid wetland habitats with closely related brown moss species: increase instead of decrease in N and P

Abstract

To test whether shifts in nutrient availability from calcareous to mineral-poor habitats could be a driving force in the evolution of seven closely related wetland brown mosses, we measured soil and vascular plant nutrients and conducted a laboratory incubation experiment with Swedish and some Dutch samples, in which net N and P-mineralization, respiration and microbial characteristics were measured. In spite of high respiration and microbial N, net N-mineralization appeared to be low for the calcareous Palustriella falcata and Scorpidium spp. Net Nmineralization significantly increased (and respiration and microbial N decreased) for the mineral-poor Sarmentypnum exannulatum, Straminergon stramineum and Warnstorfia fluitans, probably due to a decrease in microbial N-demand. Even though values were mainly negative, net P-mineralization showed a similar increase from calcareous to mineral-poor fens, probably due to lower precipitation of calcium phosphate. The calcareous habitat of the early wetland mosses may thus have been nutrient-poor instead of nutrient-rich. Adaptation to mineral-poor habitats, probably driven by expansion of mineral-poor wetlands when the boreal zone became colder and wetter, may have been associated with higher availability of ammonium and phosphate. However, this may have stimulated Sphagnum more than brown mosses, which may have been restricted to particular niches with perhaps some nitrification.

Paradoxical differences in N-dynamics between Luxembourg soils: litter quality or parent material?

“…However, net N-mineralization was generally higher on sandstone than on limestone, whether expressed as process rates, per unit C respired or per square metre. This is supported by field and laboratory studies, which reported higher net N-mineralization for acid than calcareous soil as well (Zöttle 1960;Davy and Taylor 1974;Verhoeven et al 1990;Kooijman and Besse 2002;Kooijman et al 2008, Kooijman andHedenäs 2009). Sandstone and limestone also differ in soil texture, but sandy soils had generally higher net N-mineralization than loamy soils as well (Hassink et al 1993;Hassink 1994).…”

“…Zöttle (1960) and Davy and Taylor (1974) found lower net N-mineralization in calcareous than in acid forest soils, even though they could not explain why. Verhoeven et al (1990) and Kooijman and Hedenäs (2009) measured lower net N-mineralization in base-rich than in acid peatlands, and Kooijman and Besse (2002) in dune grasslands. Naturally, N-availability to the vegetation may not only depend on net N-mineralization in the soil, as plant roots may take up organic N and actively compete with microbes for inorganic N (Schimel and Bennett 2004;Chapman et al 2006).…”

Drepanocladus trifarius– an example of unsuspected niche widths among mosses

“…Cultivation experiments and more detailed investigations of net nutrient mineralisation (cf. Kooijman and Hedenäs 2009) could cast more light on the detailed habitat requirements of D. trifarius .…”

“…Conventionally, the N values are a general indication of soil fertility (Ellenberg 1991, Dierssen 2001, Hill et al 2007). Kooijman and Hedenäs (2009) showed, however, that net N and to some degree net P mineralization, and thus plant available N and P compounds, are actually higher in mineral‐poor habitats with a relatively low pH than in mineral‐rich habitats. We considered this information for the assignment of N‐ values to the study species.…”

Long-term vegetation changes in bogs exposed to high atmospheric deposition, aerial liming and climate fluctuation

“…It increased in frequency in hummocks in the Jizerské hory Mountains and in both hummocks and hollows in the Hrubý Jeseník Mountains (Table 5). As this species has an optimum in acidic fens with increased net N mineralization (Kooijman & Hedenäs 2009), its increase in permanent plots could be caused by higher nutrient supply through atmospheric deposition. Another explanation for Straminergon stramineum spread could be increased Ca concentration, because this species tolerates moderate Ca content and also grows in the moderately rich fens of the Sphagno‐Tomentypnion alliance (Hájková 2005).…”