Biology Reference
In-Depth Information
Chapter 4
Environment and Algal Nutrition
Francisco J.L. Gordillo
4.1
Introduction
The mechanisms by which macroalgae take up nutrients from the external medium
and use them to form biomolecules have been long and widely studied (e.g., Raven
1984
; Lobban and Harrison
1994
). In this chapter, the focus is on the ecophysiology
of these mechanisms for the main nutrients C, N, and P. Particular details on uptake
and utilization mechanisms are included when considered ecophysiologically rele-
vant. Physical aspects such as water movement and seasonality are included,
nutrient availability is discussed in terms of environmental conditioning of N and
P supply for storage and growth, and different species-specific metabolic strategies
are presented. Some attention has been paid to the interference of N assimilation
with C assimilation pathways. Carbon assimilation is treated more in-depth in
on seaweeds, see Chap.
19
by Roleda and Hurd.
Nutrient uptake and assimilation mechanisms are the link between the resources
externally available and the demands for growth. However, the environment where
macroalgae develop is characterized by strong fluctuations in a number of relevant
factors including nutrients, so that macroalgae show some plasticity in terms of
resource management and internal composition of the biomass, thus rapidly
acclimating to the nutritional conditions. Algae can switch their photosynthetic
energy investment from C to N and P acquisition during the course of the day, or
from summer to winter. Most remarkably, different mechanisms of resource utili-
zation for different species coexist at the same time in the same community, and this
strategy of partitioning brings a more effective resource use, i.e., better transfer to
the whole food web.
F.J.L. Gordillo (
*
)
Departamento de Ecolog´a, Universidad de M´laga, M´laga, Spain
e-mail:
gordillo@uma.es
