Arthropods biodiversity in a landscape mosaic dominated by organic olive groves in Alentejo (Portugal)

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Acknowledgments: This work is a contribution to the Project UID/GEO/04035/2013, funded by FCT – Fundação para a Ciência e a Tecnologia, Portugal.

Arthropods biodiversity in a landscape mosaic dominated by organic olive groves in Alentejo (Portugal)

Maria Isabel Patanita¹, Paula Nozes¹, Manuel Patanita^1,2, Alexandra Tomaz^1,2 & Margarida Pereira¹

ipatanita@ipbeja.pt

1Instituto Politécnico de Beja, Escola Superior Agrária – Departamento de Biociências, Rua Pedro Soares, 7800-295 Beja, Portugal.

2GeoBioTec, Universidade Nova de Lisboa, Campus da Caparica, 2829 - 516 Caparica, Portugal

INTRODUCTION

MATERIAL AND METHODS

RESULTS

CONCLUSIONS

Table I – Total abundance of orders and families in olive groves and holm oak plot.

ORDER/FAMILY FUNCTIONAL GROUP OLIVE GROVE HOLM OAK

PLOT 1 PLOT 2 PLOT 3 PLOT 4 PLOT 5 COLEOPTERA

CARABIDAE Predator 2 4 2 2 6

COCCINELLIDAE Predator 3 8 3 13 8

STAPHYLINIDAE Predator 9 9 7 13 8

OTHER COLEOPTERA Undefined 356 358 153 862 1004

ARANEA Predator 19 50 9 26 38

HYMENOPTERA Pollinators / Parasitoids / Omnivores 221 237 106 335 506

HEMIPTERA Pest/Predator 83 52 18 44 62

DIPTERA Undefined 585 481 163 702 774

THYSANOPTERA Pest 536 330 56 388 516

LEPIDOPTERA Polinizadores 38 56 13 62 67

ORTHOPTERA Pest 0 3 7 8 16

NEUROPTERA Polinizadores 5 0 2 11 0

OTHER HEMIPTERA Pest 39 23 4 19 29

TOTAL - 1896 1611 543 2485 3034

Nº TRAPS - 18 17 6 17 18

RICHENESS - 12 12 13 13 12

Figure 2 – Time evolution of total arthropods caught in the various plots. Figure 3 – Aerial photo and sampled plots. Plots 1, 2, 3, 4 – Olive grove; Plot 5 – Holm oak forest.

In olive groves, arthropods represent an important part of the biodiversity, where they can provide multiple ecosystem services, such as the biological control of crop pests. This service helps maintaining agricultural productivity and reduces the need of pesticide inputs.

The objective of this work was to study the abundance and diversity of arthropods in a landscape mosaic dominated by organic olive groves in Alentejo, Portugal.

One landscape consisting of four olive groves in organic production and a contiguous plot dominated by holm oak (Quercus rotundifolia Lam.) were selected. Olive grove plots were covered by resident and/or sown vegetation and the holm oak plot was dominated by resident vegetation.

Three passive traps for interception of flying insects were installed in each plot, except for the third plot, where one trap was placed.

Figure 1 – Passive traps for interception of flying insects. A – Holm oak plot; B – Olive grove; C – Funnel with arthropods.

A B C

Plot 1 Plot 2

Plot 4

Plot 5 Plot 3

This was a preliminary study to characterize each area according to its biodiversity and functional groups of arthropods and to understand the effect of the landscape on the abundance of arthropods in the olive grove. In the spring months (May and June), the abundance of arthropods (Figure 2) was higher in plot 5. In comparison, in September, plots 4 and 5 contributed more to the total. In total, 9587 specimens of arthropods belonging to 10 orders were collected. The order Coleoptera was the most abundant representing 29.57%, followed by the Diptera with 28.25%, Thysanoptera with 19.08% and Hymenoptera with 14.68%. The abundance of the Carabidae, Coccinellidea and Staphilinidae families was higher in the olive grove compared to the holm oak forest, and could be an indicator of their function in the olive agroecosystem.

These traps consisted of two Plexiglas plates (52 cm x 32 cm) arranged crosswise and placed on top of a bright yellow plastic funnel (ø 34 cm) placed about 70 cm above the ground.

The funnel was filled with 2.5 L of water and detergent. The collection of arthropods was held on the 27

^th

May, 3

^rd

and 15

^th

of June, and on the 15

^th

, 22

^nd

and 30

^th

Arthropods biodiversity in a landscape mosaic dominated by organic olive groves in Alentejo (Portugal)