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2508114 
Journal Article 
Carbon economy in lichens 
Palmqvist, K 
2000 
Yes 
New Phytologist
ISSN: 0028-646X
EISSN: 1469-8137 
148 
1 
11-36 
English 
WOS:000089943700003 
Lichens are nutritionally specialized fungi (the mycobiont component) that derive carbon and in some cases nitrogen from algal or cyanobacterial photobionts. The mycobiont and phorobiont live together in an integrated thallus, but they lack specific tissue for the transport of metabolites and resources between them. Carbon is acquired through photosynthesis in the photobiont, which is active when the lichen is wet and exposed to light. Lichen photosynthesis is limited primarily by water, light and nitrogen, but can also be constrained by slow diffusion of CO2 within the wet thallus. The assimilated carbon is exported from phorobiont to mycobiont, which also predominates in terms of biomass, and apparently regulates the size of the photobiont population. It has therefore generally been assumed that most of the carbon is used for growth and maintenance of the fungal hyphae. However, the extent of photobiont respiration in relation to mycobiont respiration has seldom been quantified; neither do rye know the pool sizes of various carbon sinks within lichens. Owing to this lack of fundamental data we do not know whether, or how, carbohydrate resources are regulated to maintain an optimal balance between energy input and expenditures in these symbiotic organisms. This review summarizes data on growth, carbon gain and carbon expenditures in lichens, with particular emphasis on factors determining the photosynthetic capacity of their photobionts. An attempt is made to introduce an economic analysis of lichen growth processes, a view that has often been adopted in studies of higher plants. Areas in which more data are needed for the construction of a model on 'lichen resource allocation patterns' are discussed. 
CO2-concentrating mechanism; energy use efficiency; lichen growth; photosynthesis (lichen); resource allocation; respiration (lichen); Rubisco; water relations 
NAAQS
• ISA NOxSOxPM Ecology (2018)
     Cited in First Draft
          Chapter 6
     Cited in the Second Draft
          Appendix 6
• ISA NOxSOxPM Ecology (2020- Final Project Page)
     Cited
          Appendix 6