biologia - Studia

STRUCTURE AND DYNAMICS OF THE PREDATOR MITE’S POPULATIONS IN SHRUBS ECOSYSTEMS
2500
2000
Lunca Mare
Cornu
Nistoresti
no. ind./sq.m.
1500
1000
500
0
Leptogamasus parvulus
Veigaia nemorensis
Asca aphidoides
Geholaspis mandibularis
Hypoaspis aculeifer
species
Trachytes aegrota
Uropoda sp.
Fig. 3. The numerical densities of the dominant mites in studied ecosystems.
Table 3.
Species diversity (Shannon - Wiener index) of the identified
mites species in studied ecosystems
Ecosystem May August October Annual
Lunca Mare 2.25 2.82 2.61 3.23
Cornu 1.37 3.47 2.85 3.29
Nistoreşti 2.73 3.2 2.78 3.75
In ecosystem from Cornu were identified 15 species, with 7900 ind./sq.m.
In humus layer was recorded the most increased number of species, than in litter
and fermentation layer and in the last was the soil layer. The humus, which had a
reach content of organic matter, action as a trophical additional substratum,
determining by its structure an increasing of the species number, providing to the
mites optimal environmental conditions.
In temporal dynamics was obtained a high specific diversity in august and a
small one in may. From the numerical density point of view, the most favourable
evolution of the mite populations was in october and the less propitious in may. In
autumn, developing of the litter and fermentation layer is faster, this habitat being
prefered by the majority of descomposer invertebrates from soil-trophic source for
gamasids (Fig. 5.) (Table 3).
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