Symbiotic Fungi: Principles and Practice (Soil Biology)

294 J. Álvarez-Sánchez et al.
wind exposure can also be increased, which can cause tree damage or death
(Laurance et al. 2000; Benítez-Malvido and Martínez-Ramos 2003).
These changes also produce alterations in soil microbiota, of which one of the
most important components are the mycorrhiza-forming fungi and nitrogen-fixing
bacteria. Hart and Reader (2004) observed that the arbuscular mycorrhizal fungi of
the suborder Gigasporineae were significantly less affected by soil disturbance than
Glomineae, considering root colonization and spore density.
18.1.2 Restoration
One of the principal objectives of restoration programs should be the facilitation of
system function reestablishment, maintaining long-term stability. This could require
the restoration of soils using a native microbiotic community (Haselwandter
1997; Requena et al. 2001), especially arbuscular mycorrhizal fungi which allow
soil retention by forming aggregates and retaining organic material. This improves
soil structure and reduces or prevents water and wind erosion, along with their
respective nutrient loss (Jasper 1994; Haselwandter 1997).
Facing rapid rain forest deterioration, restoration ecology practices are extremely
necessary as they allow ecosystem recuperation. Restoration ecology is defined as a
process where the objective is to recuperate one or more ecosystem functions
or attributes. This allows the recuperation of species composition as well as their
interactions and relationships until a close resemblance to the original community is
obtained (SER 2004; Hobbs 2005). Restoration is based on successional models
in order to reconstruct the abiotic environment, and, in turn, helping natural succession
processes and a return to the original system conditions (Suding et al. 2004).
In the tropical rain forest, regeneration and succession occur naturally due to
the life histories of the species, which are adaptive responses to environmental
conditions. Light-demanding species (pioneers) occupy the first successional stages,
grow in high light environments, have rapid growth rates, produce many small fruits,
and can have invasive growth patterns and low herbivore defense capacities. Shadetolerant
species (late successional) have slower growth rates, produce larger fruits in
smaller quantities, develop more herbivore defense and can form seedling banks
(Martínez-Ramos 1994). Other species traits are shown in Table 18.1.
18.1.3 What is the Role of Arbuscular Mycorrhizal Fungi
in Habitat Recovery?
In the last decade, the use of arbuscular mycorrhizal fungi (AMF) as an additional
tool in restoration has been proved to be effective. Maintaining or reestablishing
a native community of these fungi can contribute to the recuperation of some soil
properties (Allen et al. 2003).