Ecophysiological constraints on spore establishment in bryophytes

Abstract

Summary1. Many threatened bryophytes are restricted to patchy and temporary substrates such as dead wood and tree stems. Their persistence depends on successful colonizations of new patches. Spore germination may then be limited by substrate quality and wetness. 2.In vitro experiments were used to test the effects of pH and moisture on the establishment of spores of the moss species Neckera pennata Hedw. and Buxbaumia viridis (DC) Moug. & Nestl. 3. Low pH and water potential prolonged the lag phase preceding germination and reduced final germination. The interaction between pH and moisture suggests that high water availability facilitates germination at suboptimal pH, and vice versa . 4. The results reflect the species' habitats: the wood-inhabiting B. viridis had higher capacity to germinate at low pH, while spores of the epiphyte N. pennata showed earlier germination at low water potential and survived longer in a dry state. This supports the notion that bryophytes are most strongly affected by substrate quality during establishment. 5. We suggest that a trade-off exists among moss spores between the ability to colonize substrates with low moisture-holding capacity and low pH, and that the positive effect of high pH is largely that it speeds up germination thereby enabling the spores to exploit short, moist periods.

All green, but equal? Morphological traits and ecological implications on spores of three species of mosses in the Brazilian Atlantic forest

“…within a single day to a few months; Lloyd and Klekowski Jr 1970, Pence 2000, Wiklund and Rydin 2004, Maciel da Silva et al 2009). Green spores generally germinate fast and are frequently associated to taxa with a life program adapted to moist and shaded habitats in temperate and tropical sites (Lloyd and Klekowski Jr 1970).…”

Spore germination, early development and some notes on the effects of in vitro culture medium on Frullania ericoides (Nees) Mont. (Frullaniaceae, Marchantiophyta)

“…In bryophytes, dispersal, colonization and new plant development can proceed through spore production and germination (sexual reproduction) or through vegetative diaspores or fragmentation (asexual reproduction) (Nehira 1983;Schofi eld 1985;Gradstein et al 2001;Wiklund & Rydin 2004). Once the gametophyte reaches sexual maturity, 1 Departamento de Botânica, Instituto de Ciências Biológicas, Universidade Federal de Juiz de Fora, 36036-900, Juiz de Fora, MG, Brazil and the environmental conditions are favourable, male and female multicellular gametangia are formed, antheridia and archegonia respectively.…”

“…The sporophyte, although perennial, is responsible for the production of spores, which are considered the first cell of gametophytic stage (Schofield 1985). This reproduction by producing spores enables the colonization of new substrates through dispersal mainly by wind (Zanten & Pócs 1981;Longton & Schuster 1983;Wiklund & Rydin 2004;Longton 2006;Glime 2007). In order for establishment in a new environment to be effective, a successful spore germination processes is fundamental (Glime 2007).…”

“…Many studies exist related to the germination of bryophyte spores, their stages of development and the factors influencing their success, as water and light availability, type of substrate, seasonality, among others, has been developed especially for mosses and liverworts (Inoue 1960;Vallane 1966;1971;Udar & Srivastava 1970;Mogensen 1978;Olesen & Mogensen 1978;Brown & Lemmon 1988;Alcade et al 1996;McLetchie 2001;Wiklund & Rydin 2004;Zhao et al 2004;Maciel-Silva et al 2009a;Alfayate et al 2013). Vallane (1966;1971) studied the germination of spores of Ceratodon purpureus.…”

“…Nehira (1983) described and detailed the types of development of protonema of mosses and liverworts. Wiklund & Rydin (2004) studied two mosses species regarding physiological features to spore establishment, and Zhao et al (2004) observed the characteristics of spore germination in Lindenbergia brachyptera. Maciel-Silva et al (2009a; studied the effects of water availability and light spore germination of the mosses Octoblepharum albidum and Thamniopsis incurva, taxa well represented in Brazilian bryoflora.…”