1. Coleoptera assemblages of the olive grove and the surrounding landscape in Trás-os-Montes (Portugal)
Ana M. Dinis1, Jacinto Benhadi-Marín1,2, Pedro Nascimento1,3, José A. Pereira1, José P. Sousa2, Sónia A. P. Santos1, 4*
1Mountain Research Center (CIMO), Polytechnic Institute of Bragança, Campus de Santa Apolónia, Bragança, Portugal
2 Department of Life Sciences, University of Coimbra, Coimbra, Portugal
3 Federal Institute of Rondôna, Campus Ariquemes, Ariquemes, Brasil
4Barreiro School of Technology, Polytechnic Institute of Setúbal, Rua Américo da Silva Marinho, Lavradio, Portugal. *
Introduction
Coleoptera order represents one of the most abundant and diverse group of arthropods in the olive agroecosystem. Besides providing innumerous ecosystem functions they are also important bioindicators and are capable of inhabiting different kind of systems depending on the available resources. The objective of this work was to compare assemblages of Coleoptera between the olive grove and the surrounding landscape composed mainly by shrubland, and to assess the extent to which these systems support different beetle families.
Material and Methods
Figure 1. A – Example of the experimental design; B – Olive grove; C – Shrubland; D – Collection of pitfall content; E – Detail of a sample in the laboratory. B C D E A
Pitfall trap
In 2015, 4 olive groves (Fig. 1B) located near Mirandela (northeastern Portugal) and their respective surrounding shrublands (Fig. 1C) were sampled. Nine pitfall traps were installed in each selected plot and placed apart 30 m from each other.
Sampling was conducted between the 2nd of May and the 20th of June and traps were substituted on a weekly basis (Fig. 1D).
All captured beetles were counted and identified to the level of family (Fig. 1E).
For each ecosystem the total family richness, distribution of families and the most abundant families are shown. The complementarity index (C) was calculated according to Colwell & Coddington (1994) and generalized estimating equations (GEE) were used to assess statistical differences between the olive groves and the shrublands in terms of abundance, family richness and diversity (Simpson´s Index) per plot. B C
Results ). A B C D
A total of 2243 individuals were captured belonging to 31 families. The olive groves registered higher abundance of beetles (1193) while higher family richness (30) was found in the shrublands (Table 1).
Sydmaenidae and Staphylinidae were dominant families in shrublands while Tenebrionidae and Melolonthidae in olive groves (Table 1) (Fig. 2).
Table 1. Total abundance and family richness of Coleoptera captured in the olive groves and the shrublands. 3 9 11 14 23 25 29
Shurblands
Olive groves 17
C = 0.26
Figure 2. More abundant families of Coleoptera captured in the shrublands : A – Sydmaenidae; B – Staphylinidae and in the olive groves: C – Tenebrionidae; D – Melolonthidae. *
Figure 3. Total abundance, family richness and family diversity of Coleoptera captured in both ecosystems per plot. * indicates significant differences between the two treatments. Error bars extend from the minimum to maximum value, continuous horizontal line within the boxes indicates the median and the boxes extend from the first to the third quartile.
Total abundance was not significantly different between olive groves and shrublands (W = 0.29, df = 1, P = 0.59) whereas the richness of families per plot and the diversity were in both cases significantly higher in olive groves (W = 26, df = 1, P < 0.01 and W = 20.7, df = 1, P < 0.01 respectively) (Fig. 3).
Figure 4. Families of Coleoptera exclusive in the shrublands, the olive groves and found in both ecosystems (central area). C: Complementarity index.
Conclusions
Olive groves and shrublands supported the same families of Coleoptera, since the exclusive families were represented by singletons, however, the most abundant families in each system were different and the differences in diversity may indicate that olive groves and shrublands can offer different benefits in terms of food, microclimate, humidity and refuge against predators, probably allowing population fluxes between the two ecosystems.
Future studies should be conducted considering environmental variables in order to uncover the effect of the drivers involved in the community dynamics.
Reference: Colwell R.K. & Coddington J. A., Estimating terrestrial biodiversity through extrapolation. Philosophical Transactions: Biological Sciences. Vol. 345, No Biodiversity: Measurement and Estimation:
UNIÃO EUROPEIA
Fundo Europeu de
Desenvolvimento Regional
This work is part of the project: EXCL/AGR-PRO/0591/2012: Olive crop protection in sustainable production under global climatic changes: linking ecological infrastructures to ecosystem functions, funded in the research lines of excellence of FCT.
13-15 de Abril de 2016