Keywords: GERMANY
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Keywords: DROUGHT RESISTENCE/ WATER RELATIONS/ DISTRIBUTION/ ECOPHYSIOLOGY
Abstract: 21 fig.
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Keywords: WATER RELATIONS/ ECOPHYSIOLOGY
Abstract: 5 fig.
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Keywords: ECOPHYSIOLOGY/ CLADONIA/ TEMPERATURE/ PODETIA
Abstract: 3 fig. 2 tab. ["Temperaturverlauf im Podetium einer Cladonia, " p. 383.]
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Keywords: CO2/ METABOLISM/ PELTIGERA/ CLADONIA/ PHYSIOLOGY
Abstract: 6 fig. [Mention of Peltigera praetextata and Cladonia rangiferina.]
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Keywords: AFRICA/ PARMELIA PARAGUARIENSIS/ DISTRIBUTION
Abstract: 7 fig.
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Keywords: MAURITANIA/ GONOHYMENIA/ KEY/ WEST AFRICA
Abstract: 5 fig. 1 pl. [New: Gonohymenia mauritanica sp. nov. Key to the 5 species of the genus.]
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Keywords: GONOHYMENIA/ KEY
Abstract: 1 pl. [Key to the 6 species of Gonohymenia.]
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Keywords: WATER RELATIONS/ PHOTOSYNTHESIS/ DESERT/ RAMALINA MACIFORMIS
Abstract: 1 fig.
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Keywords: CO2 GAS EXCHANGE/ TEMPERATURE/ ECOPHYSIOLOGY
Abstract: 13 fig. 1 tab.
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Keywords: CO2 GAS EXCHANGE/ PHYSIOLOGY/ CLADONIA/ USNEA/ ROCCELLA/ RAMALINA/ PHOTOSYNTHESIS
Abstract: 5 fig. [Studies on Cladonia rangiferina, Usnea dasypoga, Roccella fucoides, and Ramalina maciformis.]
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Keywords: ECOPHYSIOLOGY/ TEMPERATURE
Abstract: 1 tab.
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Keywords: PHOTOSYNTHESIS/ PHYSIOLOGY/ WATER RELATIONS
Abstract: 1 fig.
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Keywords: HYPOGYMNIA PHYSODES/ CO2 GAS EXCHANGE/ PHOTOSYNTHESIS/ TEMPERATURE/ ECOPHYSIOLOGY/ GERMANY
Abstract: 1 fig. ["Though temperature did not increase above 4 deg.C ... and light intensity was low because of snow showers, the net photosynthesis of the lichen was positive all day."--English summary.]
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Keywords: ECOLOGY/ ADAPTATIONS/ WATER RELATIONS/ ARIDITY
Abstract: 16 fig.
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Keywords: RAMALINA/ NEGEV DESERT/ ECOPHYSIOLOGY/ CO2 GAS EXCHANGE/ TEMPERATURE/ LIGHT/ WATER RELATIONS
Abstract: 17 fig. [Long summary in English. Effects of water, temperature, and light; detailed study.]
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Keywords: COLD RESISTANCE/ ADAPTATIONS/ ECOPHYSIOLOGY/ TEMPERATURE/ MACROLICHENS/ ECOLOGY
Abstract: 1 tab. [23 species.]
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Keywords: ECOPHYSIOLOGY/ COLD RESISTENCE/ TEMPERATURE
Abstract: 2 fig. 1 tab. [English summary.]
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Keywords: NEGEV DESERT/ ECOPHYSIOLOGY/ PHOTOSYNTHESIS/ MEASUREMENTS/ TECHNIQUES/ LANGE
Abstract: [Review of Lange's research in the Negev Desert.]
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Keywords: ECOPHYSIOLOGY/ WATER RELATIONS/ GAS EXCHANGE/ PHOTOSYNTHESIS/ NEGEV DESERT/ ISRAEL/ NIGHT RESPIRATION
Abstract: 12 fig. 2 tab. ["The lichen thalli are so much moistened, as a result of the nightly dew fall, that an apparent CO2-uptake is possible for a period of approx. 3 hours following sunrise.... In the natural habitat lichens, which have become dried-out during the daytime, are also capable of absorbing enought water vapour without any dew condensation from the surrounding moist air at night to enable a short period of photosynthetic acitivity during the morning. The resulting CO2-yield exceeds significantly the loss due to night respiration, so that a positive daily CO2 balance results.... The capability of the lichens to use dew moisture and water vapour to activate their photosynthetic synthesis explains their existence and distribution in the Negev."]
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Keywords: CO2 GAS EXCHANGE/ ECOPHYSIOLOGY/ NEGEV DESERT/ ISRAEL/ WATER RELATIONS
Abstract: 5 fig. 1 tab.
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Keywords: HEAVY METALS/ HISTOLOGY/ MORPHOLOGY/ AIR POLLUTION
Abstract: 4 fig. 7 tab. [The histological distribution of heavy metals in lichen tahlli.]
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Keywords: CALOPLACA/ NEGEV DESERT/ ISRAEL/ DEVELOPMENT/ ECOPHYSIOLOGY
Abstract: 3 fig. 2 tab.
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Keywords: COLD INJURY/ TEMPERATURE/ ADAPTATIONS
Abstract: 13 fig. 3 tab. ["Cold injury conclusively may only occur when ice is formed within the cells."--English summary.]
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Keywords: PHOTOSYNTHESIS/ ANTARCTICA/ PHYSIOLOGY/ ADAPTATIONS
Abstract: 6 fig.
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Keywords: WATER RELATIONS/ PHYSIOLOGY
Abstract: [Includes lichens, p. 104.]
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Keywords: NEGEV DESERT / RAMALINA MACIFORMIS / CO2 GAS EXCHANGE / ECOPHYSIOLOGY / WATER RELATIONS / ISRAEL
Abstract: [A translation from the German of an article from Flora 158B: 324-359. 1969. Processed publication.]
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Keywords: RAMALINA MACIFORMIS / CO2 GAS EXCHANGE / WATER RELATIONS / NEGEV DESERT / ISRAEL
Abstract: [A translation from the German of an article from Flora 159: 38-62. 1970. Processed publication.]
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Keywords: CO2-GAS EXCHANGE/ SO2-RESISTANCE/ ECOPHYSIOLOGY
Abstract: [A very detailed study showing "the compexity of an ecological interpretation of experimentally determined resistance phenomena." English summary.]
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Keywords: CO2 GAS EXCHANGE / SO2 RESISTANCE / POLLUTION / ECOPHYSIOLOGY
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Keywords: ADAPTATIONS/ ECOLOGY/ EVOLUTION/ DESERTS/ RAMALINA
Abstract: [Includes the classic example of Ramalina maciformis.]
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Keywords: PRIMARY PRODUCTION/ ECOLOGY/ BIOMASS/ DESERT/ PHYSIOLOGY
Abstract: 13 figures.
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Keywords: WATER RELATIONS/ ECOLOGY/ PHYSIOLOGY
Abstract: [Includes lichens.]
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Keywords: ADAPTATIONS/ DESERT/ TEMPERATURES/ WATER REALTIONS/ ECOLOGY
Abstract: 11 figures.
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Keywords: ECOLOGY/ PHYSIOLOGY/ PHOTOSYNTHESIS/ MODELS/ RAMALINA/ NEGEV/ ISRAEL/ DESERT/ RESPIRATION
Abstract: 8 figures. 3 tables.
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Keywords: ECOPHYSIOLOGY/ WATER RELATIONS/ NEGEV/ DESERT/ ISRAEL/ DEW
Abstract: 11 figures. 4 tables. [In addition to considerable data presented on gas exchange in relation to light, temperature and water content, the authors conclude that, "The existence of many lichens in the Negev is only possible because of the high frequency and regularity of dew-falls."]
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Keywords: WATER RELATIONS/ REVIEW
Abstract: [Detailed literature review of period 1975-1978. Lichen water relations mentioned on page 31.]
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Keywords: STICTA/ PSEUDOCYPHELLARIA/ WATER RELATIONS/ TASMANIA/ AUSTRALIA/ OWN
Abstract: 10 figures. 3 tables. [Physiological responses of the two taxa "account for the relative dominance of S. filix in shady habitats and P. delisei in more open sites."]
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Keywords: ECOPHYSIOLOGY/ ISRAEL/ DESERT/ PHOTOSYNTHESIS/ WATER RELATIONS/ NEGEV
Abstract: 3 tables. 6 figures. [The high lichen density and species richness are highest on northern exposures due, at least in part, to higher rates of dew imbibition and greater net photosynthetic production.]
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Keywords: CO2 EXCHANGE/ RAMALINA/ PHOTOSYNTHESIS/ RESPIRATION/ WATER RELATIONS
Abstract: 7 figures. 1 table. ["...results may be interpreted in terms of temperature-dependent CO2 diffusion resistances in imbibed lichen thalli."]
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Keywords: RAMALINA/ PHOTOSYNTHESIS/ WATER RELATIONS/ CO2 DIFFUSION/ PHYSIOLOGY
Abstract: ["We conclude that the carboxylation capacity of the lichen is not affected by high contents of liquid water. Therefore, the depression of CO2 uptake of the water saturated lichen at lower (e.g. natural) ambient CO2 must be due exclusively to increased resistance to CO2 diffusion from external air to the sites of carboxylation."]
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Keywords: PHOTOSYNTHESIS/ SONORAN DESERT/ PARMELIA/ XANTHOPARMELIA/ ACAROSPORA/ LIGHT/ TEMPERATURE/ ADAPTATION
Abstract: 2 figures. [Study on Parmelia kurokawae and Acarospora schleicheri during drying under four light regimes and five temperatures. "The relatively low temperature optima reflect the fact that the lichens are most active in winter, particularly in early morning hours."]
[Edit/Delete] [Upload PDF/URL] [ET: 1043]
Keywords: NECROLOGY/ OBITUARY/ BIBLIOGRAPHY
Abstract: 1 figure. [Tribute to Oscar Klement including a list of nomenclatural changes and a bibliography of his publications.]
[Edit/Delete] [Upload PDF/URL] [ET: 1832]
Keywords: CHILE/ OWN/ FOG ZONE/ ECOPHYSIOLOGY/ WATER RELATIONS/ GAS EXCHANGE/ EVERNIOPSIS/ USNEA/ HETERODERMIA/ RAMALINA
Abstract: 4 tables. 29 figures. ["Under controlled conditions, photosynthesis and respiration are reported as influenced by water content of the thalli, light intensity, and temperature, for selected species...." The authors conclude that the "...capability of the thalli to use air humidity as their main water source and their ability to conduct positive photosynthesis at extremely low thallus water potentials, are necessary characteristics for the existence of these species..." in the Chilean fog oasis. Measurements were made on Everniopsis trulla, Usnea lacerata, Heterodermia spinulosa, and Ramalina cactacearum.]
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Keywords: CHILE/ OWN/ FOG ZONE/ CLIMATE/ DISTRIBUTION/ WATER RELATIONS
Abstract: 16 figures. 2 tables. [A study of distributional patterns and habitat conditions of Chilean "fog oasis" lichens in Fray Jorge National Park. Authors describe two major lichen associations and discuss the lichen species' abilities to absorb water vapor from fog even though no condensation occurs. Authors measured diurnal courses of light intensity, air temperature, air humidity and lichen thallus temperature during characteristic weather conditions in various seasons of the year.]
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Keywords: PHOTOSYNTHESIS/ MINICUVETTE/ PARMELIA/ EVERNIA/ XANTHORIA/ FIELD MEASUREMENTS
Abstract: 5 figures. ["A newly developed, portable minicuvette system is described which allows quick and reliable determination of photosynthetic capacity of lichens in the field." Study includes sample data on Parmelia reticulata, Evernia prunastri, and Xanthoria parietina.]
[Edit/Delete] [Upload PDF/URL] [ET: 891]
Keywords: PHOTOSYNTHESIS/ OWN/ FIELD/ GAS EXCHANGE/ POROMETER
Abstract: 4 figures. ["A portable system for CO2 gas exchange measurements is described which allows determination of photosynthesis and respiration rates of lichens (and mosses) in the field under light, humidity and temperature conditions which are close to ambient. Between the periods of gas exchange measurement, the lichens experience their natural microclimatic conditions." Examples of gas exchange are presented for lichens south of Lisbon, Portugal.]
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Keywords: TECHNIQUE/ INSTRUMENTATION/ WATER RELATIONS/ ECOLOGY/ PHYSIOLOGY
Abstract: 8 figures. [Manufacturers bulletin describing the use of this portable CO2 gas exchange measurement system. The unit has been used for lichen and higher plant investigations.]
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Keywords: PHOTOSYNTHESIS/ WATER RELATIONS/ PHYSIOLOGY/ REACTIVATION RESPONSE
Abstract: 2 tables. 9 figures. ["The present investigation compares different types of lichens from different climatic regions with respect to their ability to be activated by water vapor uptake." Results show that "habitat adaptations are clearly recognizable" and that "... there are also distinct differences between lichen types in the response to moistening with liquid water." The gelatinous lichens apparently depend entirely on liquid water for photosynthetic acitivation unlike all the others.]
[Edit/Delete] [Upload PDF/URL] [ET: 887]
Keywords: TECHNIQUE/ CO2 EXCHANGE/ PHOTOSYNTHESIS/ MEDITERRANEAN/ POROMETER/ PARMELIA/ CLADONIA/ PARMOTREMA
Abstract: 1 table. 12 figures. [Studies conducted using Parmelia reticulata and Cladonia portentosa in Portugal are described. Authors give extensive description and explanation of the use of a portable CO2-porometer and the development of a model for lichen CO2 exchange. "Our experience suggests that we can expect to improve our model many times before it satisfactorily reproduces the real-world situation. Instrumentation has been described here which permits these kinds of investigations."]
[Edit/Delete] [Upload PDF/URL] [ET: 890]
Keywords: TECHNIQUE/ CO2 EXCHANGE/ PHOTOSYNTHESIS/ WATER RELATIONS/ TRANSPIRATION
Abstract: 8 figures. [Manufacturers bulletin describing the use of this portable porometer system. The unit has been used for lichen and higher plant investigations.]
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Keywords: GERMANY/ GARMISH/ ALPS/ AIR POLLUTION/ SPRUCE/ PHYTOSOCIOLOGY/ SO2/ PHOTOSYNTHESIS/ CO2 EXCHANGE
Abstract: 8 tables. 4 figures. [Study of lichens, SO2 pollution, and spruce tree damage in the Bavarian Alps. "In the present study there were no indications of any impact of sulphur dioxide on the viability or physiological activity of the epiphytic lichens. A rich vegetation of lichens, including sensitive species, was found growing even directly on branches of spruce trees which were damaged, as indicated by chlorosis and loss of needles." Authors conclude " ... from these findings, that a direct influence of atmospheric sulphur dioxide is likely not the cause of the observed tree damage."]
[Edit/Delete] [Upload PDF/URL] [ET: 1863]
Keywords: WATER RELATIONS/ NEPHROMA/ PELTIGERA/ ECOPHYSIOLOGY/ PHOTOBIONT/ NOSTOC/ LOBARIA/ PHOTOSYNTHESIS/ RESPIRATION
Abstract: 8 figures. [Studies on species of several genera. "Carbon isotope ratios of the lichen thalli suggest that a definite ecological difference exists in water status-dependent photosynthesis of species with green and blue-green phycobionts. Apparently, a fundamental difference in the structure of the two groups of algae is involved."]
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Keywords: PHOTOSYNTHESIS/ PHYSIOLOGY/ CO2 EXCHANGE/ REACTIVATION/ WATER RELATIONS
Abstract: 7 figures. 2 tables. ["It was shown by analyzing CO2 exchange that air-dry thalli of lichens with green algae as phycobionts can be reactivated to attain net photosynthesis by supply with humid air alone or with liquid water, while dry thalli from lichens with cyanobacteria need liquid water. This is true in the latter group for gelatinous, homoiomerous species as well as for the non-gelatinous, heteromerous. These different reactivation types are also found in species of one genus, if they contain green or blue green phycobionts."]
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Keywords: PSEUDOCYPHELLARIA/ WATER RELATIONS/ PHOTOSYNTHESIS/ ISOTOPES/ PHOTOBIONTS/ PHOTOSYMBIODEMES
Abstract: 4 tables. 2 figures. ["Green lichens have been shown to attain positive net photosynthesis in the presence of water vapour while blue-green lichens require liquid water.... The behaviour is confirmed not only for species with differing photobionts in the genus Pseudocyphellaria but for green and blue-green photobionts in a single joined thallus (photosymbiodeme), with a single mycobiont, and also when adjacent as co-primary photobionts. The different response is therefore a property of the photobiont. It is proposed that the presence of sugar alcohols in green algae allow them to retain a liquid pool (concentrated solution) in their chloroplasts at low water potentials and even to reform it by water vapour uptake after being dried."]
[Edit/Delete] [Upload PDF/URL] [ET: 1645]
Keywords: ECOPHYSIOLOGY/ MEDITERRANEAN/ POIKILOHYDRIC
Abstract: 16 figures. 1 table. ["Primary production of lichens is governed through their thallus water content and time periods of metabolic activity are restricted. Species with green algae are even able to make use of high air humidity without hydration by liquid water." Reprinted, in essence, in the Journal of Ecology 76: 915-937.]
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Keywords: WATER RELATIONS/ POIKILOHYDRIC/ MEDITERRANEAN/ PHOTOSYNTHESIS
Abstract: 19 figures. 1 table. [Summary of many investigations on a number of lichen species and comparisons with higher plants.]
[Edit/Delete] [Upload PDF/URL] [ET: 1641]
Keywords: CALIFORNIA/ PHYSIOLOGY/ SALINITY/ DENDROGRAPHA/ PSEUDOCYPHELLARIA/ EVERNIA/ RAMALINA/ PHOTOSYNTHESIS/ RESPIRATION
Abstract: 3 figures. 2 tables. ["Sensitivity to salinity varied widely among 12 Californian lichen species occurring along a coastal to inland gradient, with the degree of sensitivity being approximately proportional to the distance from the coast where the species grew." Authors also conclude, "The results of the experiments with different solutions at equal osmotic potentials indicate that the sensitive species are responding to both osmotic and salt ion effects. These species may provide a good system for investigating mechanisms involved in purely osmotic versus ionic effects."]
[Edit/Delete] [Upload PDF/URL] [ET: 1656]
Keywords: PHOTOSYNTHESIS/ PRIMARY PRODUCTIVITY/ WATER RELATIONS/ MICROCLIMATE/ TERRICOLOUS/ BAVARIA/ GERMANY/ CO2 EXCHANGE
Abstract: 22 figures. ["For each season of the year there were specific cases of weather conditions which could be classified into uniform types, and the related responses in net photosynthesis and water status are described in schemes and diurnal courses. Further results, as general light and water content dependent photosynthesis curves derived from the measured parameter, and seasonally shifting photosynthesis responses which occurred in some species, are discussed."]
[Edit/Delete] [Upload PDF/URL] [ET: 1594]
Keywords: ALGAE/ CYANOBACTERIA/ PHOTOBIONT/ WATER RELATIONS/ PHOTOSYNTHESIS/ CHLOROPHYLL FLUORESCENCE/ DESICCATION/ RAMALINA/ PELTIGERA
Abstract: 6 figures. ["Both lichens differed not only with respect to their ability to rehydrate and reactivate photosynthetic functions by water vapour uptake, but also with respect to the speed of the restitution of the photosynthetic apparatus after sudden hydration of dry thalli by liquid water." The authors conclude that " ... the reactivation of photosynthesis in blue-green algae-containing lichens is not prevented through high diffusion resistance for water."]
[Edit/Delete] [Upload PDF/URL] [ET: 1643]
Keywords: ALGAE/ ENERGY DISSIPATION/ CAROTENOIDS/ CHEMISTRY/ ADAPTATIONS/ PHOTOPROTECTION/ ZEAXANTHIN
Abstract: 2 tables. 4 figures. ["We conclude that the pronounced difference in the capicity for photoprotective energy dissipation in the antenna chlorophyll (zeaxanthin-containing) green algal lichens and (zeaxanthin-free) blue-green algal lichens is related to the presence or absence of zeaxanthin, and that this difference can explain the greater susceptibility to high-light stress in lichens with blue-green phycobionts."]
[Edit/Delete] [Upload PDF/URL] [ET: 1568]
Keywords: PHYCOSYMBIODEME/ LIGHT STRESS/ XANTHOPHYLLS/ CAROTENOIDS/ PSEUDOCYPHELLARIA
Abstract: 1 table. 4 figures. [Study on Pseudocyphellaria rufovirescens-P. murrayi phycosymbiodeme. "These findings represent further evidence that zeaxanthin is involved in the photoprotective dissipation of excessive excitation energy in photosynthetic membranes. The difference in the capacity for rapid zeaxanthin formation between the two partners of the Pseudocyphellaria phycosymbiodeme may be important in the habitat selection of the two species when living separate from one another."]
[Edit/Delete] [Upload PDF/URL] [ET: 1569]
Keywords: PHOTOCHEMISTRY/ ENERGY CONVERSION/ PHOTOBIONTS/ ALGAE/ PHOTOSYNTHESIS/ LIGHT STRESS
Abstract: 2 tables. 4 figures. ["It will thus be important to examine the response of lichens to the interaction of natural light levels and hydration status, and to evaluate the importance of light as a stress factor which may influence the distribution of species."]
[Edit/Delete] [Upload PDF/URL] [ET: 1570]
Keywords: WATER RELATIONS/ CHONDROPSIS/ XANTHOMACULINA/ CLADONIA
Abstract: 1 figure. 2 tables. [Water relations and photosynthesis in Chrondropis semiviridis, Xanthomaculina convoluta, and Cladonia convoluta.]
[Edit/Delete] [Upload PDF/URL] [ET: 1646]
Keywords: NEGEV DESERT/ ISRAEL/ CRUSTOSE/ GROWTH RATE/ CALOPLACA/ DIPLOSCHISTES
Abstract: 6 figures. 1 table. ["It can be cautiously estimated that a Caloplaca aurantia thallus 10 cm in diameter near Avdat can be estimated to have an age of about 135 years. Because the largest thallus of this species found near Avdat can be estimated to have an age of about 500 years, it is certainly one of the oldest "individual" organisms in this area."]
[Edit/Delete] [Upload PDF/URL] [ET: 1642]
Keywords: TELOSCHISTES/ NAMIBIA/ AFRICA/ FOG ZONE/ FRUTICOSE/ DESERT/ WATER RELATIONS/ DESERT/ PHOTOSYNTHESIS
Abstract: 2 tables. 8 figures (3 in color). ["It is instructive to imagine that every morning after nightly fog and dew for a short period of time Teloschistes capensis in the lichen fields of the Namib Desert is photosynthesizing with rates similar to those of a closed layer of beech leaves in a forest in Germany." Authors estimate a net gain for a year's growth of about 20% of the active biomass of the lichen.]
[Edit/Delete] [Upload PDF/URL] [ET: 1648]
Keywords: PHOTOSYNTHESIS/ ALGAE/ PHYCOBIONT/ DROUGHT STRESS/ DESICCATION/ PROTECTION/ MYCOBIONT
Abstract: 2 tables. 4 figures. ["We found no difference between the effects of low water potential on intact lichens and their liberated algal components (ground thallus material and isolated algae) and no indication that the fungal component of the lichen symbiosis protects the phycobiont from the adverse effects of desiccation once equilibrium conditions are reached. The photosynthetic apparatus of the phycobiont alone proved to be highly adapted to water stress as it possesses not only the capacity of functioning under extremely low degrees of hydration but also of becoming reactivated solely by water vapor uptake."]
[Edit/Delete] [Upload PDF/URL] [ET: 1649]
Keywords: WATER RELATIONS/ PHOTOSYNTHESIS/ RESPIRATION/ PHYSIOLOGY/ SALINITY/ CALIFORNIA/ RAMALINA/ PSEUDOCYPHELLARIA/ EVERNIA
Abstract: 1 table. 2 figures. [Study of photosynthetic and respiratory rates was conducted on Ramalina menziesii, Dendrographa minor, Evernia prunastri, and Pseudocyphellaria anthraspis from California by changing water potential through desiccation or osmotic stress using sea salt or sorbitol solutions. "These species provide a model system to differentiate the effect of atmospheric desiccation and osmotic stress on lichen metabolism, and to study the interaction of drought per se with other stress factors such as salt and high light."]
[Edit/Delete] [Upload PDF/URL] [ET: 1657]
Keywords: CO2 EXCHANGE/ PHOTOSYNTHESIS/ PRIMARY PRODUCTION/ SAND DUNES
Abstract: 23 fig. 1 tab. ["In its natural habitat of stabilized dunes on the island Baltrum (North Sea), microclimatic conditins for Cladonia portentosa were recorded (air and thallus temperature, rel. humidity, photosynthetically active radiation). In parallel, water content of the lichen (WG, % of dry weight) was determined. With respect to lichen hydration, the 56 diurnal courses of measurements, which were spread over several seasons could be grouped into 5 different types: (1) WG continuously low; (2) nocturnal moistening (e.g. by dew fall) and high WG at sunrise; (3) days with fog and high WG throughout; (4) days with rain and long lasting high WG; (5) lichens covered by snow. In addition, during 24 days in the summer and in the winter, diurnal courses of CO2 exchange of the lichen were followed together with the WG and the microclimatic conditions. These days could be separated according to the above types. This provides an overview for the performance in production ecology of the lichen."]
[Edit/Delete] [Upload PDF/URL] [ET: 1554]
Keywords: BLUE-GREEN ALGAE/ HYDRATION/ WATER RELATIONS
Abstract: 12 fig. ["It is known from previous investigations that dry lichens with green algae are able to recover net photosynthesis through rehydration with water vapor, whereas all blue-green lichens tested so-far lack this ability." This study, using critical point drying and SEM to compare the phycobionts of Ramalina maciformis and Peltigera rufescens, indicates that the blue-green phycobionts (Nostoc) do not become rehydrated and turgid without liquid water.]
[Edit/Delete] [Upload PDF/URL] [ET: 1562]
Keywords: DESICCATION/ DROUGHT/ LIGHT/ PHOTOSYNTHESIS/ SHADE
Abstract: 8 fig. [This ecologiclly unusual cyanobacterial species is found to have very unusual water and light relations. It is extremely shade tolerant and also less tolerant to drying than even the very desiccation-sensitive aquatic lichens. The study was conducted in the laboratory.]
[Edit/Delete] [Upload PDF/URL] [ET: 1592]
Keywords: ADAPTATIONS/ DESICCATION/ LIGHT/ LIGHT SATURATION/ PHOTOSYMBIODEMES/ SHADE/ WATER RELATIONS/ WATER STORAGE
Abstract: 6 fig. 7 tab. ["These lichens exhibit a great diversity of both form and habitat range. Physiological and morphological adaptation has also been demonstrated. Pseudocyphellaria dissimilis shows changes in thallus water storage capacity with evaporative demand and is also highly shade-adapted. The species has the lowest light saturation and compensation values for photosynthesis yet known for lichens (20 and 1 µmol m-2s-1, PAR, respectively). Unexpectedly it is also highly desiccation-sensitive with some thalli being killed after only 20 h exposure to 15% relative humidity." The physiological differences between the green algal and cyanobacterial sectors of the P. rufovirescens-P. murrayi photosymbiodeme are also investigated.]
[Edit/Delete] [Upload PDF/URL] [ET: 1593]
Keywords: EDIBILITY/ FEEDING DETERRENCE/ LEPIDOPTERA
Abstract: [Both acetone and water extracts from 12 selected lichens were incorporated into an artificial diet for feeding tests with the larvae of this Lepidopteran.]
[Edit/Delete] [Upload PDF/URL] [ET: 2107]
Keywords: CO2 EXCHANGE/ PHOTOSYNTHESIS/ PRIMARY PRODUCTION
Abstract: 13 fig. 2 tab. ["Photosynthesis and dark respiration of the lichen Cladonia portentosa was studied under controlled conditions in the laboratory. There was good agreement with respect to the absolute rates of CO2 exchange as well as in response to single factors between the laboratory results and performance of the lichen in the field. The dependencies of CO2-gas exchange on incident photosynthetically active radiation, thallus temperature, and thallus-water content were described with a series of equations. These functions were combined in a general model which simulates net photosynthesis in response to all three environmental factors. The model was validated against observed diurnal courses of CO2 exchange which were obtained in the natural habitat of the lichen. Field performance is reproduced well by the model although deviations may occur in extreme environmental situations.]
[Edit/Delete] [Upload PDF/URL] [ET: 1644]
Keywords: FOG ZONE/ NAMIB DESERT/ NAMIBIA/ PHOTOSYNTHESIS/ SOUTH AFRICA/ WATER RELATIONS
Abstract: 13 fig. 4 tab. [Detailed field studies on photosynthesis and water relations in ten species characteristic of the Namib Desert (Alectoria sp., Caloplaca elegantissima, Heterodermia cf. erinacea, Neofuscelia namaensis, Ramalina lacera, Santessonia hereroensis, Teloschistes capensis, Xanthomaculina convoluta, X. hottentotta, Xanthoparmelia walteri.). "The characteristics of a species, especially its growth form, determine maximal rate of photosynthesis and the ability of the lichen to make use of the available moisture. The multibranched fruticose species (e.g., Teloschistes capensis, Alectoria spec., Ramalina lacera) reach higher rates of net photosynthesis than the more compact foliose lichens (e.g., Xanthomaculina convoluta, X. hottentotta, Xanthoparmelia walteri), both their maximal apparent quantum use efficiency (initial slope of the light response curve) and their maximal photosynthetic rates at light saturation being greater."]
[Edit/Delete] [Upload PDF/URL] [ET: 1647]
Keywords: ANNUAL PRODUCTION/ CO2 EXCHANGE/ PHOTOSYNTHESIS/ PRIMARY PRODUCTION
Abstract: 5 fig. 3 tab. ["In the spring, summer and fall, days with rain resulted in the greatest CO2 fixation, followed by days with fog and by days with nocturnal hydration which took place mainly by dew fall. In contrast during winter, the average CO2 uptake on rainy days was much less due to low light intensities, and days with dew fall were associated with the highest CO2 gain. The fall was the season during which estimates of CO2 fixation by the lichen were greatest, however, photosynthetic productivity during spring and in the summer was similar in magnitude. In contrast, carbon gain in the winter was less than half of that predicted for the other seasons. In the annual total, 66% of the net production of the lichen resulted due to moistening by rain, 22% by fog, and 10.4% to nocturnal moistening by dew condensation. The integrated balance of the photosynthetic production of the lichen for a typical year was 27.9 mmol CO2 per g dry weight. This annual carbon gain equals ca. 79% of the carbon content of the thallus. Apparently only a small proportion of this primary production is incorporated into new biomass of the slowly growing lichen. We suggest that excess carbon fixation may be necessary due to substantial leaching of assimilates, especially during moistening by rain. This assimilated carbon may be lost due to the open structure of the lichen thallus."]
[Edit/Delete] [Upload PDF/URL] [ET: 1555]
Keywords: CO2 DIFFUSION/ CO2 EXCHANGE/ GAS EXCHANGE
Abstract: 8 fig. 6 tab. 9 equations [Laboratory study using one liverwort, Monoclea forsteri, and five lichens, Pseudocyphellaria faveolata, P. colensoi, Sticta fuliginosa, S. latifrons, and Ramalina maciformis.]
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[ET: 1745]
Keywords: CO2 EXCHANGE/ CYANOBACTERIA/ DESERT/ DUNES/ PHOTOSYNTHESIS/ SOIL CRUSTS
Abstract: 7 fig. 1 tab. [These crusts are formed by at least one moss, four blue-green algae, and two green algal species. Although the crusts include no lichens, their photosynthetic characteristics are compared to various Negev lichens and lichen soil crusts.]
[Edit/Delete] [Upload PDF/URL] [ET: 2314]
Keywords: PHOTOSYNTHESIS/ PHYSIOLOGY/ WATER RELATIONS
Abstract: 37 fig. (including many color photos.) [Brief popular account of lichen ecophysiology.]
[Edit/Delete] [Upload PDF/URL] [ET: 1707]
Keywords: CO2 EXCHANGE/ POROMETER/ TECHNIQUES
Abstract: 2 fig. [Describes a special lichen cuvette developed for the CO2/H2O Porometer in cooperation with the Walz company.]
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Keywords: ARCTIC/ COMMUNITY INTERACTIONS/ MICROCLIMATE/ POIKILOHYDRIC/ TUNDRA/ WATER RELATIONS
Abstract: 9 fig. 3 tab. [Review of the role of mosses and lichens in the tundra ecosystem.]
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[ET: 1747]
Keywords: BLUE-GREEN ALGAE/ CAROTENOIDS/ METABOLISM/ PHOTOPROTECTION/ ZEAXANTHIN
Abstract: 7 fig. 2 tab. [Thirty-three species of green algal lichens and five species with blue-green algae were studied and compared to the leaves of higher plants.]
[Edit/Delete] [Upload PDF/URL] [ET: 2378]
Keywords: CARBONIC ANHYDRASE/ CO2 CONCENTRATING MECHANISM/ CO2 FIXATION/ CYANOBACTERIA/ GREEN ALGAE/ PHOTOSYNTHESIS
Abstract: 11 fig. 1 tab. [Eleven species with green algal photobionts and six species with cyanobacterial photobionts were investigated. "Using a CO2-gas-exchange system, which allowed resolution of fast transients, evidence was obtained for the existence of an inorganic carbon pool which accumulated in the light and was released in the dark."]
[Edit/Delete] [Upload PDF/URL] [ET: 2382]
Keywords: CYANOBACTERIA/ GREEN ALGAE/ PHOTOSYMBIODEMES/ PHOTOSYNTHESIS/ PSEUDOCYPHELLARIA/ WATER BALANCE/ WATER RELATIONS
Abstract: 5 fig. ["The photosynthesis of the components of two Pseudocyphellaria photosymbiodemes were studied in the natural forest environment in New Zealand. It was found that the green algal component had a large photosynthetic advantage when thallus water contents were low and the thalli were in equilibrium with atmospheric humidity. The cyanobacterial components were at an advantage when thallus water contents were very high."]
[Edit/Delete] [Upload PDF/URL] [ET: 2930]
Keywords: CO2 EXCHANGE/ DRYING PERIOD/ PHOTOSYNTHESIS/ WATER RELATIONS
Abstract: 9 fig. 6 tab. [Detailed field study of CO2 exchange relative to water content and microclimate conditions in seven lichen species: Masonhalea richardsonii, Cetraria cucullata, Stereocaulon alpinum, Thamnolia vermicularis, Dactylina arctica, Peltigera aphthosa, P. malacea. "Even short periods of favourable hydration were used by lichens for positive net photosynthesis (NP). There was no indication of adverse consequences of "resaturation respiration." Even after a dry period of 3 days, sudden rehydration resulted in carbon gain without delay. For short periods of time, the combinations of water content, temperature and light imposed on the lichens enables high rate of NP. Individual species differed greatly in their maximal NP rate, which correlated with chlorophyll and nitrogen content. At favourable times in the field, observed NP rates approached the maximum capacity found in the laboratory experiments at natural ambient CO2. Often with sufficient hydration, carbon gain was limited by light. CO2 exchange became negative even during daylight hours due to the effects of fog and clouds with light below compensation levels. Reduced but still positive rates of NP were observed with snow and with frozen lichens."]
[Edit/Delete] [Upload PDF/URL] [ET: 2313]
Keywords: CO2 EXCHANGE/ DIFFUSION/ DIFFUSIVE RESISTANCE/ PHOTOSYNTHESIS/ RAIN FORESTS/ WATER CONTENT/ WATER RELATIONS
Abstract: 8 fig. 1 tab. ["CO2 exchange rate in relation to thallus water content (WC, % of dry weight) was determined for 22 species of lichens, mainly members of the genera Pseudocyphellaria and Sticta, from a temperate rainforest, Urewera National Park, New Zealand. All data were obtained in the field, either using a standard technique in which the lichens were initially wetted (soaked or sprayed, then shaken) and allowed to slowly dry, or from periodic measurements on samples that were continuously exposed in their natural habitat. A wide range of WC was found, with species varying from 357 to 3360% for maximal WC in the field, and from 86 to 1300% for optimal WC for photosynthesis."]
[Edit/Delete] [Upload PDF/URL] [ET: 2412]
Keywords: CYANOBACTERIA/ PHOTOSYNTHESIS/ WATER RELATIONS
Abstract: 5 fig. 1 tab. ["In contrast to green algal lichens, cyanobacterial species of different families, growth forms and habitats proved to be unable to attain positive net CO2 assimilation when the dry thalli were treated with air of high relative humidity; they needed liquid water for the reactivation of their photosynthetic apparatus. Identical behaviour is shown by all of the 47 lichen species with cyanobacterial photobionts, from six different genera, studied so far."]
[Edit/Delete] [Upload PDF/URL] [ET: 2312]
Keywords: ADAPTATIONS/ CORTEX/ EPINECRAL LAYER/ HABITAT SELECTION/ LIGHT TRANSMISSION/ PELTULA
Abstract: 16 fig. 1 tab. [An investigation of cortical structure in four species of Peltula, and of light transmission rates to the cyanobiont layer. New: P. farinosa Büdel sp. nov.]
[Edit/Delete] [Upload PDF/URL] [ET: 2564]
Keywords: ANTIHERBIVORE PROTECTION/ GRAZING/ HERBIVORE/ INSECTS/ INVERTEBRATES
Abstract: 1 fig. 3 tab. ["Fourteen frequently occurring lichen substances including two depsides, seven depsidones and four pulvinic acid derivatives as well as an anthraquinone, were studied for their influence on growth and development of the polyphagous herbivore Spodoptera littoralis."]
[Edit/Delete] [Upload PDF/URL] [ET: 2557]
Keywords: CO2 COMPENSATION/ CO2 CONCENTRATING MECHANISM/ CO2 DIFFUSION/ ECOPHYSIOLOGY/ PHOTOSYNTHESIS/ WATER BALANCE/ WATER CONTENT
Abstract: 12 fig. 2 tab. ["Lichens are poikilohydric plants and, as such, their thallus water content (WC) tends to equilibrate with the atmospheric humidity. An analysis is made of the typical response of lichen photosynthesis to thallus WC which is a three (subjectively delimitated) phase curve. At low WC the metabolism is thought to be limited by the low water potential and net photosynthesis (PN) is almost linearly related to WC. Green algal lichens show the special ability to achieve positive PN by equilibration only with atmospheric humidity. Factors that limit maximal PN at optimal WC have yet to be satisfactorily described. At high WC many lichens show a depression in PN and the evidence is summarised to show that this is a result of increased thallus CO2 diffusion resistances."]
[Edit/Delete] [Upload PDF/URL] [ET: 2561]
Keywords: PHOTOSYNTHESIS/ PHOTOSYNTHESIS RATES/ POIKILOHYDRIC/ PRODUCTIVITY/ SHADE/ WATER CONTENT/ WATER STORAGE/ WATER TRANSPORT
Abstract: 3 fig. 5 tab. [Review paper.]
[Edit/Delete] [Upload PDF/URL] [ET: 2558]
Keywords: BASIDIOLICHENS/ CO2 CONCENTRATING MECHANISM/ DICTYONEMA/ PHOTOSYNTHESIS/ PRODUCTIVITY/ RAIN FORESTS/ WATER BALANCE/ WATER CONTENT
Abstract: 10 fig. 1 tab. ["Diel time courses of microclimate, hydration, and CO2 exchange of the basidiolichen Dictyonema glabratum and its responses to experimentally changed conditions were measured for 14 days in a clearing of a premontane, tropical rainforest (Panama). Net photosynthesis (NP) was adapted to high temperatures and there was no depression of CO2 uptake at the highest thallus hydration. The presence of a CO2 concentrating mechanism was demonstrated. Decreased NP occurred after desiccation, and apparent photon yield of CO2 fixation was also sensitive to water loss. Natural NP was controlled by the interplay of thallus hydration and radiation. Regular, daily desiccation and dense cloud cover suppressed production. On average, 72% of the diurnal photosynthetic gain was lost during the night, and there were days with negative carbon balance. Nevertheless, total carbon gain of the lichen was extremely high. A tentative estimation suggests that annual carbon gain amounts to 228 % of initial thallus carbon content. Because of their strong effect on net production, increased nocturnal temperatures as given at lower elevation, would lead to a negative carbon balance. This might explain the lack of abundance of this and other macrolichens in warmer, lowland forests."]
[Edit/Delete] [Upload PDF/URL] [ET: 2562]
Keywords: CYANOBACTERIA/ HYDRATION/ MICROCOLEUS/ PHOTOSYNTHESIS/ SOIL CRUSTS/ WATER ABSORPTION/ WATER BALANCE/ WATER VAPOR
Abstract: 2 fig. 1 tab. [This species, as it occurs in its natural summer state in desert soil crusts, proved unable to reactivate photosynthetic metabolism solely by hydration in equilibrium with high air humidity. However, desiccated populations in lab culture attained turgor and were able to photosynthesize in equilibrium with a relative air humidity as low as 96%.]
[Edit/Delete] [Upload PDF/URL] [ET: 2559]
Keywords: CO2 EXCHANGE/ COMPENSATION POINT/ NAMIB DESERT/ PHOTOSYNTHESIS/ PHOTOSYNTHESIS RATES/ RESPIRATION/ SOIL CRUSTS/ WATER RELATIONS
Abstract: 7 fig. 1 tab. [Photosynthetic and respiratory CO2 exchange rates were studied in three species: Acarospora cf. schleicheri, Caloplaca volkii, and Lecidella crystallina. "Area-related, maximal, daily net photosynthetic carbon gain of the three species under natural conditions was 158-290 mg C m-2 day-1. A very rough, first estimate of the annual carbon balance of the soil-crust lichens (photosynthetic gain minus respiratory losses) was 16 g C m-2 year-1."]
[Edit/Delete] [Upload PDF/URL] [ET: 2563]
Keywords: CANTHAXANTHIN/ CAROTENOIDS/ CHLOROPHYLL/ CYANOBACTERIA/ CYANOLICHENS/ HPLC/ LIGHT INTENSITY/ LIGHT SCREENING/ TLC/ ZEAXANTHIN
Abstract: 4 fig. 3 tab. ["Lipophilous carotenoids together with chlorophyll a were extracted in acetone from 1) a variety of cyanobacterial lichens stemming from habitats with strongly different light exposure, ranging from the Judean Desert, Israel, to a shaded forest floor in Germany, 2) Peltigera praetextata collected from a deciduous forest in the vicinity of Würzburg at bimonthly intervals during an entire year, and 3) Peltigera species which in a short term experiment (five days) had been exposed to altered light conditions with respect to those they had grown under. Pigment determination by high performance liquid chromatography (HPLC) showed no clear trend in the concentrations of zeaxanthin (and echinone) under different incident light intensities. In contrast, canthaxanthin contents increased and the concentrations of chlorophyll a and ß-carotene decreased with enhanced light exposure of the lichens. This was observed for all three types of investigation and indicates that the ratio of canthaxanthin to ß-carotene in a cyanobacterial lichen is strongly influenced by the light environment it has recently grown in."]
[Edit/Delete] [Upload PDF/URL] [ET: 2560]
Keywords: CO2 CONCENTRATION/ ECOLOGY/ PHOTOSYNTHESIS/ PHYLLOPLANE/ RAIN FORESTS/ RESPIRATION
Abstract: 4 fig. 2 tab. ["In this temperate rainforest community, the environment within the mosses and lichens is significantly richer in CO2 than the atmosphere both within and outside the forest. Moss phylloplane CO2 levels averaged 50%, and lichen thalli CO2 levels 10% higher, than in the air outside the forest."]
[Edit/Delete] [Upload PDF/URL] [ET: 3331]
Keywords: CORTEX/ MECHANICAL DAMAGE/ PSEUDOCYPHELLARIA/ RAINFALL/ WATER RELATIONS
Abstract: 2 fig. [Peeling of the upper cortex induced by heavy rainfall is reported.]
[Edit/Delete] [Upload PDF/URL] [ET: 2740]
Keywords: CO2 EXCHANGE/ EXPOSURE/ GAS EXCHANGE/ LIGHT/ SHADE/ SUN FORMS/ WATER CONTENT
Abstract: 8 fig. 4 tab. ["The gas exchange of six temperate rain forest lichens was measured in the field in the Urewera National Park, New Zealand." Comparison of the effects of thallus water content and light on gas exchange in shade species, sun species, and marginal species.]
[Edit/Delete] [Upload PDF/URL] [ET: 2932]
Keywords: ANTIFEEDANT ACTIVITY/ ANTIHERBIVORE PROTECTION/ ARCTIIDAE/ CHEMICAL DEFENSE/ CLADONIA/ FEEDING PREFERENCES/ FUMARPROTOCETRARIC/ HPLC/ INSECT LARVAE/ INSECTS/ LEPIDOPTERA/ MOTHS/ SEQUESTRATION
Abstract: 2 fig. 2 tab. [Analysis of wild caught moths (eight genera, 16 species) for lichen substances, and preliminary feeding experiments with larvae of one species.]
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Keywords: PHOTOSYNTHESIS/ SOIL CRUSTS/ THALLUS HYDRATION/ WATER CONTENT/ WATER RELATIONS
Abstract: 5 fig. [Study of net photosynthesis and its dependence on thallus water content in seven lichens. "The relationships found between NP and WC could be divided into four response types based on the degree of depression of NP at maximal WC. Type A lichens (Cladonia convoluta, Diploschistes muscorum) showed no or almost no depression, type B (Squamarina lentigera) only a little at the highest thallus water contents. Type C (Collema tenax, Toninia sedifolia) had a large depression which became steadily greater as water content increased; type D lichens Cladonia pocillum, Fulgensia fulgens) behaved similarly, but the response curve had an inflection so that NP became low but almost constant."]
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