A marine gastropod fossil found at Crozier wassent to Dr. Leo Hertlein at the California Academyof Sciences for identification and study. A report onhis findings was published in this journal (vol. IV,no. 5, p. 199-201).

The Johns Hopkins program was assisted in thefield at various times by David Ainley, MichaelSmith, Jack Hood, Frank Kurek, John Gemming,and Mikal Saltveit. We gratefully acknowledge theirassistance.

References

Sladen, W. J . L., R. C. Wood, and W. B. Emison. 1966.Antarctic avian population studies, 1965-1966. AntarcticJournal of the U.S., I (4): 141-142.

Sladen, W. J . L., R. E. LeResche, and R. C. Wood. 1968a.Antarctic avian population studies, 1967-1968. AntarcticJournal of the U.S., III (6) : 247-249.

Sladen, W. J . L., R. C. Wood, and E. P. Monaghan. 1968b.The USARP bird-banding program, 1958-1965. AntarcticResearch Series, 12: 213-262.

Stonehouse, B. 1953. The emperor penguin, Aptenodytesforsteri: 1, Breeding behaviour and development. FalklandIslands Dependencies Survey. Scientific Report No. 6.

Wilson, E. A. 1907. Ayes. British National Antarctic Expedi-tion (1901-1904). Reports, Natural History, 2: 1-31.

Wood, R. C., R. E. LeResche, and W. J . L. Sladen. 1967.Antarctic avian population studies, 1966-1967. AntarcticJournal of the U.S., 11(4): 101-103.

Russian MonographsSubmitted for Translation

NSF's Polar Information Services has submittedthe following Russian monographs for translation tothe Clearinghouse for Federal Scientific and Tech-nical Information:

Gleser, S. I. Cryptogamic Flora of the U.S.S.R.,vol. 7: Silico flagellates. Moscow, U.S.S.R. Academyof Sciences, V. L. Komarovii Institute of Botany,1966. 332 p.

U.S.S.R. Academy of Sciences. Tectonics of Eur-asia. Moscow, 1966. 437 p.

Arctic and Antarctic Scientific-Research Institute.Tenth Soviet Antarctic Expedition: General Descrip-tion and Scientific Results. Leningrad, 1969. 474 p.(Transactions of the Soviet Antarctic Expedition,vol. 49.)

Arctic and Antarctic Scientific-Research Institute.Eleventh Summer Expedition, 1965-1966: GeneralDescription and Scientific Results. Leningrad, 1969.133 p. (Transactions of the Soviet Antarctic Expedi-tion, vol. 50.)

Photosynthesis and Respiration of Plantsin the Antarctic Peninsula Area

T. P. GANNUTZ

Department of BiologyClark University

During the period January 17 to December 14, 1968,a third year of study of the metabolism of lichens,mosses, and algae was carried out at Palmer Station,with data being collected virtually uninterrupted for320 days. In anticipation of this extended data col-lection period, an automated, digital data acquisi-tion system had been incorporated into the instru-mentation in December of 1967. This system, in addi-tion to recording at least 100 times more data in a24-hour period than previously possible (a completesample of all variables is obtained at least 6 timeseach hour), applies the recorded data directly todetailed computer analysis, eliminating the need formanual preparation of digital data for computerentry.

This is the first time that the environmental meta-bolic responses of any plant or plant community havebeen examined throughout an entire year. Meteoro-logical and plant-microclimatic conditions were alsomeasured during this period, permitting estimates tobe made of the annual productivity of the antarcticplant community.

The weather is extremely mild at Palmer Stationduring the summer (December-March). There arefrequent rain and snow storms which, with the warmtemperatures (almost continuously above freezing—sometimes reaching + 10°C.) and high light inten-sities (1.5-2.0 gcal/cm 2 /min) , provide water to main-tain plants almost continuously in a saturated tonear-saturated condition. Most environmental com-binations during this period are favorable for highrates of both photosynthesis and respiration. Lichenphotosynthetic rates average five times the respira-tion rates during the summer, providing for the ac-cumulation of a considerable surplus of metabolicproducts. During the fall (April-June), average dailylight intensities and temperatures decrease, but pre-cipitation in the form of rain and snow is still fre-quent. Although conditions for metabolism are lessoptimal than during the summer months, photosyr:-thesis still occurs.

Respiration rates decrease as temperatures ap-proach freezing. Mosses do not conduct photosyn-thesis and respiration as well as lichens do in thisperiod. Grasses are even less active, being damagedby below-freezing temperatures. All plants are photo-synthetically inactive during the winter months(July-September), when temperatures frequently

March-April 1970 49

1'11O1). ?. P. UUII1iUtZ

Figure 2. Field study site at old Palmer Station, summer 1968.

Figure 1. Palmer Station in summer.

average —25°C. with little available light (less than0.1 gcal/cm2/min) . However, mosses and lichens arenormally located beneath a protective snow and icecover that maintains their temperature above —6°C.almost continuously.

Lichens occasionally respire at extremely low ratesduring this period. Temperatures begin to moderateand the light intensity increases during the springmonths (October–November). Lichens, mosses, andalgae located beneath the snow and ice are saturatedby melting and are exposed early in the season tobegin their recovery from winter inactivity. (Grassesare still completely inactive and generally brown incolor owing to the absence of chlorophyll.) Mossesare metabolically active during early spring, but lich-ens do not demonstrate photosynthetic and respira-tory potentials as they did during summer and fall.In early spring, maximum photosynthetic rates areonly approximately twice those of respiration, al-though the microclimatic conditions are favorable formetabolism. Respiration in early spring occurs onlyafter lichens have been able to photosynthesize forat least a few hours during the day. Lichens generallycannot utilize the low light intensities and tempera-tures which were optimal for photosynthesis duringthe fall. By late spring, lichens recover physiologicallyfrom the winter damage and achieve their metabolicrates of the previous summer and fall.

These seasonal variations have interesting physio-logical implications. The antarctic grasses are dam-aged by the low temperatures (0°C. and below) of

the fall, winter, and spring. However, they are peren-nials, and their metabolic activity is concentratedduring the summer months, when temperatures arehigher and water is available. Mosses are inactiveduring the winter, but are very active during thespring, summer, and fall. Although mosses do notdemonstrate a reduction in early spring photosyn-thetic capability as lichens do, they cannot utilize thewide range of environmental conditions that the lich-ens can. Mosses cannot photosynthesize at tempera-tures below —4°C. and light conditions below 0.1gcal/cm2/min . On the other hand, they do not ceaseto metabolize at temperatures above 10 to 15°C., asdo lichens. In general, lichens are physiologically bet-ter adapted to antarctic stress conditions than mosses.

The physiological responses of lichens to their en-vironment and the changing nature of the symbioticassociation throughout the year are extremely inter-esting. Although space limitations do not permit pres-entation of extensive data here, some speculationscan be made on the implications suggested by thepreliminary results.

Lichens can photosynthesize and respire at lowertemperature, light, and water conditions than otherantarctic plants, and they are extremely resistant toenvironmental extremes. By regulating their metabo-lism, they can take advantage of favorable micro-climatic conditions and then enter a semi-restingstate during unfavorable microclimatic conditions.The thallus water content is the primary metabolicregulatory mechanism of lichens: as the temperaturesand/or light intensities rise to unfavorable levels, thethalli dry and become metabolically inactive. Artifi-cially water-saturated lichens subjected to high tem-peratures and strong light still demonstrate reduction

50 ANTARCTIC JOURNAL

I'hoto: 7. P. (Jannutz

Figure 3. Metabolism chambers. Plants are placed in thesechambers to determine changes in carbon-dioxide levels as a

result of photosynthesis and/or respiration.

1'hfo: T. 11 . (;ani,ufz

Figure 4. Instrumentation and acquisition systems for metabolic,microclimatic, and meteorological data. Palmer Station, winter

1968.

in metabolic activity, suggesting a physiological en-vironmental adaption.

Metabolic regulation by water content of the thal-lus implies that a low thallus water content will re-duce the damaging effects of high respiration rates,which would quickly exhaust food reserves. Such areduction in food reserves would induce increasedfungal parasitism on algal cells. Availability of liquidwater is responsible for the ability of lichens to photo-synthesize at temperatures below freezing. Lichenscharacteristically produce great quantities of chemicalcompounds which are deposited within the thallus.This high concentration of chemical compoundscould prevent thallus water from freezing at tempera-tures below 0°C.: the water-saturated thalli of several

species of lichens were observed to remain unfrozenat temperatures of - 10°C. The majority of antarcticlichen thalli are highly pigmented and contain a highconcentration of chemical compounds.

Variability of lichen photosynthetic capability dur-ing different seasons suggests a variation in both thethallus algal population and the nature of the lichensymbiosis. Lichen algae achieve a high density in thethallus during summer months, when conditions arealmost continuously favorable for photosynthesis. Thishealthy algal population produces sufficient quantitiesof photosynthetic products for fungal activities. Sum-mer is also favorable for respiration; however, photo-synthesis is conducted at five times the respirationrate. In fall, when temperatures and light intensitiesare lower, respiration is also reduced—many timeseliminated—but photosynthesis continues. Photosyn-thesis, however, is virtually eliminated once the lightand temperatures reach winter lows. Respiration, al-though reduced considerably, occurs occasionally astemperatures permit.

The fungi require raw materials from the algaethroughout the winter, although fungal and algalactivities are considerably reduced. Prior to the endof the winter and the return of conditions favorablefor photosynthesis, the fungi have depleted their algalstorage materials. The lichen fungi then become moreparasitic upon thallus algae in order to maintaintheir reduced activities. Consequently, much of thealgal population is destroyed by fungal parasiticpenetrations during the course of the winter. Thisintense fungal action continues until conditions be-come favorable for active photosynthesis. Once algalcells can produce sufficient photosynthetic productsto pass materials to the fungus (in the spring), fungalparasitic activities diminish. At this point, fungi andalgae proliferate within the confines of the thallus ina more mutualistic, symbiotic relationship. This con-dition is emphasized by the observation that, duringearly spring, lichen thalli are capable of high respira-tion rates (comparable to respiration conducted dur-ing similar microclimatic conditions of summer andfall) at night only after they have been able to photo-synthesize during the previous 24-hour period. Plantsartificially covered during all daylight hours wereincapable of respiring at significant rates during thenight, suggesting a critical reduction in metabolicstorage products toward the end of the winter andin early spring.

Climatic conditions which can be considered astress upon the lichen symbionts (winter, when thefungus is in a state of semi-starvation due to algalinactivity) are important for maintaining the annualsymbiotic balance and promoting growth of the lich-en thalli. An ideal lichen microenvironment will pro-vide a balance of conditions both favorable and un-favorable for photosynthesis. During stress conditions,

March-April 1970 51

which are not favorable for metabolism in general,respiration continues intermittently at reduced rates.This sequence of conditions maintains the lichen sym-biosis throughout the year, although the degree ofparasitism varies. If the stress periods were too long,the lichen fungi would destroy many algal cells, in-creasing the time required for renewal of the algalpopulation during times of favorable conditions. Inthe absence of stress periods of sufficient duration,both algae and fungi would proliferate, possibly grow-ing out of the symbiosis. Consequently, algal metabo-lism is regulated primarily by microclimatic condi-tions, and fungal metabolism is regulated primarilyby the availability of algal photosynthetic products.Both controls are critical for the maintenance of thelichen thallus.

Different world climatic regions are characterizedby environmental complexes which are interpreted bylichens inhabiting those regions as stress or optimalmetabolic periods. The manner in which lichens in aparticular region respond to their environment canbe termed metabolic balance (the ratio of annualphotosynthesis to annual respiration). Each speciesof lichen has a critical metabolic balance whose main-tenance depends upon microclimate. The metabolicbalance determines which species will inhabit a re-gion and the rate of growth of those lichen speciesin that particular region.

Each world climatic region is inhabited by lichensadapted to that particular region. They cannot bemoved from one climatic region to another, as dem-onstrated by the author's previous research. However.within each general climatic region (e.g., the Ant-arctic) there are climatic subdivisions. Plants withina particular climatic region are more abundant inareas where the metabolic balance is optimal for thatspecies, i.e., provides sufficient periods of stress andof optimal conditions for metabolic activity. Thisbalance provides for optimal lichen symbiotic de-velopment and growth. Such an area for the Ant-arctic is the Anvers Island region of the AntarcticPeninsula. The same species of lichens are foundnorth and south of this location, but the relativeabundance is lower.

Upon receiving a B.E. (1928) and Ph.D. in Elec-trical Engineering (1931) at Johns Hopkins Univer-sity, Dr. Joyce began his career in Federal Govern-ment science, to be interrupted only by active dutyas a naval officer for five years in World War II.After service with the Bureau of Mines, the Coastand Geodetic Survey, Navy, State, and Defense, hejoined the National Science Foundation in 1955 ashead of its Office for the International GeophysicalYear. He was also head of the successor unit, theOffice of Special International Programs, from 1958to 1961, when the Government initiated the U.S.Antarctic Research Program to continue the scientificwork beyond the IGY. In 1960, he traveled to Ant-arctica to tour TJSARP facilities and observe theprogram which he had been instrumental in establish-ing. Following two years as a special assistant to theDirector of NSF, Dr. Joyce returned to the Depart-ment of State to become Deputy Director of Inter-national Scientific and Technological Affairs.

Dr. Joyce held membership in many scientific so-cieties and served for four years as Secretary of theInternational Association for Terrestrial Magnetismand Electricity. He was also President of the Sectionon Terrestrial Magnetism and Electricity of theAmerican Geophysical Union for four years.

Book on Soviet Antarctic ResearchAvailable in English

The following monograph has been translatedinto English for the National Science Foundationand is available at $3.00 per copy from the Clearing-house for Federal Scientific and Technical Informa-tion, U.S. Department of Commerce, Springfield,Virginia 22151:

U.S.S.R. Academy of Sciences. National Commit-tee for Antarctic Research. Soviet Antarctic Research,1956-1966: Proceedings of a Conference. Edited byV. A. Bugaev. 218 p. (TT 69-55004).

Coming in Next IssueJ. Wallace Joyce, 1907-1970

J . Wallace Joyce, who died on January 6, 1970, atthe age of 62, had been associated with the inceptionof the present era of U.S. activities in Antarctica thatcommenced with the International Geophysical Year.

52

The May—June issue of the Antarctic Journal willfeature a collection of articles on Gondwanaland andcontinental drift. Authorities on various types of evi-dence for an earlier supercontinent in the SouthernHemisphere will discuss the current state of knowl-edge in their fields of specialty.

ANTARCTIC JOURNAL*U. S. GOVERNMENT PRINTING OFFICE : 1970 391991/1