THE ECOLOGY OF ARCTIC AND ALPINE PLANTS
Summary ‘How are plants adapted to the low temperatures and other stresses of arctic and alpine environments ?’ At present it is not possible to answer this question completely. Much work remains to be done, particularly on low‐temperature metabolism, frost resistance, and the environmental cues and...
| Published in: | Biological Reviews |
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| Main Authors: | , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Wiley
1968
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1111/j.1469-185x.1968.tb00968.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1469-185X.1968.tb00968.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-185X.1968.tb00968.x |
| Summary: | Summary ‘How are plants adapted to the low temperatures and other stresses of arctic and alpine environments ?’ At present it is not possible to answer this question completely. Much work remains to be done, particularly on low‐temperature metabolism, frost resistance, and the environmental cues and requirements for flowering, dormancy, regrowth, and germination. However, in brief, we can say that plants are adapted to these severe environments by employing combinations of the following general characteristics: 1. Life form: perennial herb, prostrate shrub, or lichen. Perennial herbs have greatest part of biomass underground. 2. Seed dormancy: generally controlled by environment; seeds can remain dormant for long periods of time at low temperatures since they require temperatures well above freezing for germination. 3. Seedling establishment: rare and very slow; it is often several years before a seedling is safely established. 4. Chlorophyll content: in both alpine and arctic ecosystems not greatly different on a land‐area basis from that in temperate herbaceous communities. Within a single species there is more chlorophyll in leaves of arctic populations than in those of alpine populations. 5. Photosynthesis and respiration: ( a ) These are at high rates for only a few weeks when temperatures and light are favourable. ( b ) Optimum photosynthesis rates are at lower temperatures than for ordinary plants; rates are both genetically and environmentally controlled with phenotypic plasticity very marked. (c) Dark respiration is higher at all temperatures than for ordinary plants; rate is both genetically and environmentally controlled, with phenotypic plasticity very pronounced, i.e. low‐temperature environment increases the rate at all temperatures. ( d ) Alpine plants have higher light‐saturation values in photosynthesis than do arctic or lowland plants; light saturation closely tied to temperature. (e) There is some evidence that alpine plants can carry on photosynthesis at lower carbon dioxide concentrations ... |
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