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FLUCTUATION OF BIODIVERSITY PATTERNS FOLLOWING REAFFORESTATION WITH INDIGENOUS VERSUS EXOTIC TREE SPECIES

Objective

The objectives of the project are: to set up a general model of biodiversity changes related to afforestation patterns; and to appreciate the relative value of tree species in reafforestation regarding biodiversity preservation or restoration.

Biodiversity, as the most accurate estimate of the state of ecosystems, will be examined in this project in relation to reafforestation. The underlying hypothesis is that exotic trees should not sustain the same level of biological diversity as indigenous trees. Organisms which have coevolved with original vegetation might not find adequate habitat in a new type of vegetation. This hypothesis will be tested by measuring the impact of reafforestation with different tree species on invertebrates diversity, which represent the largest part of total biodiversity. Studies will be carried out in France, Spain and Portugal, on some of the main trees used for reafforestation; Eucalyptus species, Picea abies, Pinus species, and Pseudotsuga menziesii. Major natural forest ecosystems of Europe will be involved (ie beech, spruce, mediterranean to medioeuropean oaks, and Pinus pinaster forests).

Collembola and Oniscidea, among the most important soil arthropods, will be used as references for biodiversity estimation. Curculionidae, Lepidoptera and plants will be considered also in some cases. Correlations of different parameters with both faunistic data and type of reafforestation should provide keys to the determinism of biodiversity fluctuations.

The main steps of the project areas follows.
First, standardized procedure for soil sampling: 2 plots, 8 m{2} (plantation and remnant patch of original vegetation) at each study site, homogenous in aspect, topography and edaphic substrate; 32 samples of 250 cm{3} per plot (litter and soil); extraction of fauna by Berlese; recorded parameters of age of plantation, previous and climatic vegetation, spatial structure of vegetation, soil profile, litter production, soil temperature and percentage carbon dioxide in litter. Collecting of phytophagous insects by pitfall trap and net. Seasonal sampling in all cases, control samples during the second year.
Second, identification and counting of animals and soil analyses (organic matter(OM), granulometry, pH, RFU) by specialized laboratories.
Third, computer assisted data processing following the same statistical method.

Coordinator

UNIVERSITE PAUL SABATIER DE TOULOUSE III
Address
Route De Narbonne 118
31062 Toulouse
France

Participants (3)

Centre National de la Recherche Scientifique (CNRS)
France
Address
Moulis
09200 Saint-girons
Universidad Autónoma de Madrid
Spain
Address
Cantoblanco
28049 Madrid
Universidade de Coimbra
Portugal
Address
Largo Marques De Pombal
3049 Coimbra