Growth of foliose lichens: a review

Abstract

This review considers various aspects of the growth of foliose lichens including early growth and development, variation in radial growth rate (RaGR) of different species, growth to maturity, lobe growth variation, senescence and fragmentation, growth models, the influence of environmental variables, and the maintenance of thallus symmetry. The data suggest that a foliose lichen thallus is essentially a 'colony' in which the individual lobes exhibit a considerable degree of autonomy in their growth processes. During development, recognisable juvenile thalli are usually formed by 15 months to 4 years while most mature thalli exhibit RaGR between 1 and 5 mm yr −1 . RaGR within a species is highly variable. The growth ratesize curve of a foliose lichen thallus may result from growth processes that take place at the tips of individual lobes together with size-related changes in the intensity of competition for space between the marginal lobes. Radial growth and growth in mass is influenced by climatic and microclimatic factors and also by substratum factors such as rock and bark texture, chemistry, and nutrient enrichment. Possible future research topics include: (1) measuring fast growing foliose species through life, (2) the three dimensional changes that occur during lobe growth, (3) the cellular changes that occur during regeneration, growth, and division of lobes, and (4) the distribution and allocation of the major lichen carbohydrates within lobes.

Studies on the growth of rhizocarpon geographicum in nw scotland, and some implications for lichenometry

“…Armstrong (1983Armstrong ( , 2005, Haworth et al (1986), Bradwell and Armstrong (2007), and Benedict (2008) all found a general decrease in lichen growth rate with increasing size, after an optimum diameter is surpassed (~30-50 mm). In contrast, Matthews (1994) found no decrease in growth rate in even the largest thalli (>100 mm).…”

“…Bradwell and Armstrong (2007) reported mean diametral growth rates (averaged over 4.33 years) of between 0.6-1.0 mm yr -1 (thalli >10 mm diameter) in maritime southern Iceland. Armstrong's (1983Armstrong's ( , 2005 detailed studies recorded mean growth rates of 1.0-1.5 mm yr -1 in maritime north Wales. Winchester and Chaujar (2002) found similar, but slightly faster (~1.6 mm yr -1 ) growth rates in Capel Curig, North Wales -a site experiencing exceptionally high rainfall.…”

Growth of crustose lichens: a review

“…Further evidence for a declining phase in growth in larger thalli comes from a recent study of 134 thalli of four crustose lichen species growing at a single site in north Wales (Armstrong 2005b) and a study of R.…”

“…In the absence of a suitable growth model for crustose lichens, second-order polynomial curves have been fitted to these data (Armstrong 2005b). However, further growth studies and especially those concentrating on smaller and larger-sized thalli are needed to define the shape of the size-growth curve more accurately.…”

Mapping and Early Transplantations of Threatened Lobaria Species in Conservation Center, Cibodas Botanical Garden

“…During lichen transplantation, there are several factors that must be considered for succesful transplantation, they are kind of substrate, climate, abiotic factors (temperature, humidity, light intensity, wind direction and speed, precipitation, etc.) (Armstrong and Bradwell, 2000), techniques of transplantation, and control of transplant (Coppins and Coppins, 2005).…”