INVESTIGADORES
BEAMUD Sara guadalupe
congresos y reuniones científicas
Título:
THE COPAHUE-CAVIAHUE SYSTEM (37° 53 S, 71° 02 W): NUTRIENTS (C, N, P), SEDIMENTS AND ACIDOPHILIC ALGAE
Autor/es:
BAFFICO, G.; BEAMUD, S.G.; DIAZ, M.; PEDROZO, F. & TEMPORETTI, P.
Lugar:
Bariloche
Reunión:
Congreso; 18th Simposio Internacional de Biohidrometalurgia; 2009
Resumen:
<!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;
mso-font-charset:0;
mso-generic-font-family:roman;
mso-font-pitch:variable;
mso-font-signature:-1610611985 1107304683 0 0 159 0;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{mso-style-unhide:no;
mso-style-qformat:yes;
mso-style-parent:"";
margin:0cm;
margin-bottom:.0001pt;
mso-pagination:widow-orphan;
mso-layout-grid-align:none;
punctuation-wrap:simple;
text-autospace:none;
font-size:12.0pt;
mso-bidi-font-size:10.0pt;
font-family:"Times New Roman","serif";
mso-fareast-font-family:"Times New Roman";
mso-ansi-language:EN-GB;
mso-fareast-language:ES;}
.MsoChpDefault
{mso-style-type:export-only;
mso-default-props:yes;
font-size:10.0pt;
mso-ansi-font-size:10.0pt;
mso-bidi-font-size:10.0pt;}
@page Section1
{size:21.0cm 842.0pt;
margin:2.0cm 42.55pt 70.9pt 42.55pt;
mso-header-margin:36.0pt;
mso-footer-margin:36.0pt;
mso-paper-source:0;}
div.Section1
{page:Section1;}
-->
The aim of this work
is to summarize the 10-years information about the ecological studies in the
naturally acidified area which includes the Copahue Volcano, the Upper Rio
Agrio, the lake Caviahue and the Lower Rio Agrio. The river has a strong pH gradient, from the source (pH 0,8), entering
in the Caviahue lake at pH » 2, to the neutrality .
The TP concentration
of the Agrio River spans almost two orders of
magnitude from its source to the inflow to the lake. The N concentrations were
10 times lower, mainly as ammonium. The P exported of the basin (2500
KgP/Km2/yr), the TP concentration and the SRP:TP ratio increased following the
volcanic activity. The Caviahue Lake receives 245 Tons P/yr and 21 Tons N/yr, being
the Agrio River the main contributor (P=98%;
N=71%). In the sediments, the main P-fraction is bounded to OM
showing high correlations between TP and C.
Biodiversity
is very low as a result of extreme environmental conditions, being the Chlorophyceae
the prevailing algae group. Phytoplankton is nitrogen limited and has the
capacity to use alternative sources of Carbon, different of CO2. The
high affinity of the microalgae for CO2 and the apparent absence of
a Carbon Concentration Mechanisms, suggests that photosynthesis and growth rates
are unlikely to be limited by CO2.
The algal biomass and
species diversity of the periphyton surveyed along an acid-neutral gradient of
the Agrio River showed that pH increased and conductivity decreased as the
Agrio River receives tributaries of different chemical characteristics. The
dilution of concentration of the elements (SO4, Cl, Ca, Fe, Al and
TP) is the main process, but the precipitation of a Fe and Al occurs as a
consequence of the pH increase producing changes in the structure and biomass
of the algae.