The biology of lichen communities in Livingston Island (Antarctic).

In English:

Scientific objectives:

-The evaluation of photosynthesis and respiration of significant macrolichen
species in the Antarctic tundra;
-Study of isoenzymes in bipolar lichens;
-Microclimatic study in lichenous communities;
-To continue the study of the primary development of lichen symbiosis;
-Study on lichenometry;
-Study of flora;
-Microhabitat microbiology associated with umbilicated lichens.

Activities carried out:

By means of open circuit gaseous interchange techniques, open circuit dish
studies were made on complete cycles of wet-drying (5-6 days) at temperatures
of +5 degrees, 0 degrees and -2 degrees C in the following species: Ramalina
terebrata, pseudophebe pubescens, Umbilicaria nylanderina, Parmelia saxatalis,
Sphaerophorus globosus and Stereocaulon alpinum. With the aim of carrying out
comparative studies of metabolic and ecophysiologycal interspecific differences
in bipolar lichens, preparations were made of the following species:
Pseudophebe pubescens, Sphaerophorous globosus, Umbilicaria nylanderina,
Parmelia sexatilis, Stereocaulon alpinum, Psoroma hypnorum, Peltigera spuria,
Physcia caesia, these species will be treated with electroforeses techniques.
Microclimatic readings were effected at four stations at different altitudes
along a line traced from the sea to the top of Monte Reina Sofia. The
automatically registered and stored data refer to: light, temperature and
humidity. The first 141 samples (out of 900 collected in the first campaign)
were collected in order to determine primary development of lichenous
symbiosis. These samples will be analyzed by scanning electron microscopy. A
study of lichonometry was begun in a small moraine from which the glacier has
recently receded, in order to determine primary lichenous colonization. The
species selected for this study are: Caloplaca sublobulata, Buellia
latemarginata, Aspicilia glaciaris, Rhizocarpon geographicum, Acarospora
macrocyclos and Usnea antarctica. Flora exploration on Livingston Island was
continued, with samples collected from previously unknown areas, among others:
False Burdick Nunatak, coastal nunnataks in Hurd Peninsula and Ereby Point.
Isolation and culture of bacteria which live in association with Umbilicaria
kraschenninikovii were carried out, with a view to later metabolic study and
analysis.

En Espanol:

Objetivos cientificos:.

-Evaluacion de la fotosintesis y respiracion de especies de macroliquenes
significativas en la tundra antartica.
-Estudio de las isoenzimas en liquenes bipolares.
-Estudio microclimatico en comunidades liquenicas.
-Continuacion del estudio del desarrollo primario en la simbiosis de
liquenes.
-Estudio de liquenometria
-Estudio de la flora
-Microbiologia de microhabitats asociados a liquenes umbilicados.

Actividades llevadas a cabo:

A traves de tecnicas de intercambio gaseoso en circuitos abiertos se hicieron
estudios de antenas de circuitos abiertos completados por ciclos humedo-seco
(5-6 dias) a temperaturas de +5 grados, 0 grados y -2 grados C en las
siguientes especies: Ramalina terebrata, pseudophebe pubescens, Umbilicaria
nylanderina, Parmelia saxatalis, Sphaerophorus globosus and Stereocaulon
alpinum. Con el objetivo de llevar a cabo estudios comparativos de diferencias
interespecificas metabolicas y ecofisiologicas en liquenes bipolares, se
hicieron preparaciones de las siguientes especies: Pseudophebe pubescens,
Sphaerophorous globosus, Umbilicaria nylanderina, Parmelia sexatilis,
Stereocaulon alpinum, Psoroma hypnorum, Peltigera spuria, Physcia caesia, estas
especies seran tratadas con tecnicas electroforeses. Se efectuaron lecturas
microclimaticas en 4 estaciones a diferentes latitudes a lo largo de una linea
trazada desde el mar hasta la cima del Monte Reina Sofia. Los datos registrados
automaticamente y almacenados se refieren a: luz, temperatura y humedad. Se
recogieron las primeras 141 muestras de las 900 colocadas durante la pasada
campana para determinar el desarrollo primario de la simbiosis liquenica. Estas
muestras seran analizadas con microscopio electronico. Se empezo un estudio de
liquenometria en una pequena morrena desde la cual el glaciar ha retrocedido
recientemente, para determinar la colonizacion liquenica primaria. Las
especies elegidas para este estudio son: Caloplaca sublobulata, Buellia
latemarginata, Aspicilia glaciaris, Rhizocarpon geographicum, Acarospora
macrocyclos and Usnea Antarctica. Se continuo la exploracion de flora en la
isla Livingston, se recogieron muestras de areas previamente desconocidas,
entre otras: Nunnatak Falso Burdick, nunnatak costeros en la ladera de la
Peninsula Hurd y Punta Ereby.Fue llevado a cabo el aislamiento y cultivo de las
bacterias que viven en asociacion con Umbilicaria kraschenninikovii, con vistas
a un estudio y analisis metabolico posterior.