@misc{10481/54796,
year = {2019},
url = {http://hdl.handle.net/10481/54796},
abstract = {Atmosphere is an important route through which many elements are transported
long distances from their sources. Atmospheric particles, known as aerosols, have
multiple origins, both natural and anthropogenic. Natural sources, such as sea salt and
dust, are responsible for almost 90% of global aerosol emissions (SCHLESINGER, 1997).
Arid and semiarid regions are the main sources of soil dust to the atmosphere and,
among them, the Sahara desert is the world’s major source of soil dust, with an annual
production of 400-700·106 tons per year, almost 50% of the global dust production
(SCHÜTZ ET AL. 1981; D’ALMEIDA, 1986; SWAP ET AL. 1996).
Every year, large amounts of desert dust are exported from the Sahara to the
North Atlantic Ocean and the Mediterranean region. The transport towards Atlantic
Ocean is linked to the general atmospheric circulation that has predominant wind
directions from west and northwest. By contrast, northward transport of dust over the
Mediterranean is influenced by the presence of cyclones (MOULIN ET AL. 1997). The
seasonal pattern of African dust transport over the Mediterranean shows a maximum
dust load in the central and eastern basins during spring, and in the central and
western basins during summer (MOULIN ET AL. 1997). The Iberian Peninsula, located in
the western basin, receives African dust mainly during late spring and summer under
particular meteorological conditions (RODRIGUEZ ET AL. 2001).
Atmospheric deposition can play a major role in biogeochemical cycling in both
terrestrial and aquatic ecosystems. Inputs of elements from the atmosphere have
sustained the productivity of Hawaiian rainforests during millions of years (CHADWICK ET
AL. 1999), and atmospheric deposition can account for 34% of the calcium required for
Quercus ilex forest growth in northeastern Spain (AVILA ET AL. 1997). On the other hand,
there are growing evidences that atmospheric inputs have an impact on marine
chemical cycling and on biological processes in the sea (DUCE ET AL. 1991). Atmospheric
deposition is the major input of iron to the open ocean (DUCE & TINDALE, 1991) and
atmospheric input of phosphorus can represent up to 14% of total primary production
demands in the open western Mediterranean Sea (RIDAME & GUIEU, 2002).
The role of atmospheric deposition in the biogeochemistry of freshwater
ecosystems has been less explored relative to marine ecosystems and most of the effort
has been focused on the effects of acid rain (SULLIVAN ET AL. 1990; KOPAČEK ET AL. 1995;
TAIT & THALER, 2000). The contribution of atmospheric inputs of nutrients and
Elvira Pulido Manuel de Villena. TESIS DOCTORAL
4
oligoelements to biological processes and chemical properties of lakes has been scantly
assessed (PETERS, 1977; GIBSON ET AL. 1995).
There are around 50 lakes in the Sierra Nevada mountains (SE Spain) located at
elevations of 2800-3100 m above sea level. They are located above tree line in a
remote area far from human activity. This location along with their oligotrophic nature
make these lakes ideal sites to assess the impact of dust deposition on freshwater
ecosystems.
In this study, two lakes with contrasting catchments located in the Sierra Nevada
mountains were selected. La Caldera Lake is located on rocky terrain, has no inlets
and, hence, does not receive any inputs from stream runoff. In contrast, Río Seco Lake
is located in a catchment covered by alpine meadows and has temporary inlets that
drain water from the catchment.
The main goal of this PhD thesis is to assess the influence of atmospheric
deposition on the biogeochemistry of these two high mountain lakes. This question is
addressed in four different chapters that represent the main topics of this study.},
organization = {Tesis Univ. Granada.},
publisher = {Universidad de Granada},
keywords = {Atmófera},
keywords = {Sierra Nevada},
keywords = {Lagunas},
title = {El papel de la deposición atmosférica en la biogeoquímica de laguna de alta montaña (Sierra Nevada, España)},
author = {Pulido Manuel de Villena, Elvira},
}