Effects of agriculture on the structure of plant-pollinator interaction webs in the Pampas of Argentina

MARRERO H.J.; MEDAN D.; TORRETTA J. P.

Bariloche, Río Negro

Congreso; VI Southern Connection; 2010

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} @page Section1 {size:595.3pt 841.9pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:35.4pt; mso-footer-margin:35.4pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> Agriculture expansion and intensification is affecting biodiversity worldwide, and is suspected to alter pollination interactions in the Argentine Pampas through loss of habitats used by native plants and insects. We compared network metrics obtained over 5 consecutive months at two continually cultivated plots (C) and two long uncultivated (>20 years) nearby plots (U) in the Inland Pampa, Argentina. On average, cumulated webs supported by U plots were 2.2 times larger than those of C plots, had more links per species (1.5 vs. 1.3), and displayed higher nestedness (0.18 vs. 0.045), but did not appreciably differ in robustness. Our result indicate that agriculture affects plant pollinator webs inducing loss of mutualistic species and reducing redundancy of interactions, and underline the importance of uncultivated habitats as refuges for organisms excluded from agricultural networks.