Não existe depressão de ecosistema nas florestas europeias após o Cretáceo?

No post-Cretaceous ecosystem depression in European forests? Rich insect-feeding damage on diverse middle Palaeocene plants, Menat, France

Torsten Wappler 1,*, Ellen D. Currano 2,3, Peter Wilf 4, Jes Rus t1 and Conrad C. Labandeira 5,6

+ Author Affiliations

1Division of Palaeontology, Steinmann Institute, Nussallee 8, 53115 Bonn, Germany

2Department of Geology, Miami University, Oxford, OH 45056, USA

3Huffington Department of Earth Sciences, Southern Methodist University, TX 75205, USA

4Department of Geosciences, Pennsylvania State University, University Park, PA 16802, USA

5Department of Paleobiology, Smithsonian Institution, Washington DC 20560, USA

6Department of Entomology, University of Maryland, College Park, MD 20742, USA

*Author for correspondence (twappler@uni-bonn.de).

Abstract

Insect herbivores are considered vulnerable to extinctions of their plant hosts. Previous studies of insect-damaged fossil leaves in the US Western Interior showed major plant and insect herbivore extinction at the Cretaceous–Palaeogene (K–T) boundary. Further, the regional plant–insect system remained depressed or ecologically unbalanced throughout the Palaeocene. Whereas Cretaceous floras had high plant and insect-feeding diversity, all Palaeocene assemblages to date had low richness of plants, insect feeding or both. Here, we use leaf fossils from the middle Palaeocene Menat site, France, which has the oldest well-preserved leaf assemblage from the Palaeocene of Europe, to test the generality of the observed Palaeocene US pattern. Surprisingly, Menat combines high floral diversity with high insect activity, making it the first observation of a ‘healthy’ Palaeocene plant–insect system. Furthermore, rich and abundant leaf mines across plant species indicate well-developed host specialization. The diversity and complexity of plant–insect interactions at Menat suggest that the net effects of the K–T extinction were less at this greater distance from the Chicxulub, Mexico, impact site. Along with the available data from other regions, our results show that the end-Cretaceous event did not cause a uniform, long-lasting depression of global terrestrial ecosystems. Rather, it gave rise to varying regional patterns of ecological collapse and recovery that appear to have been strongly influenced by distance from the Chicxulub structure.

Palaeocene Europe herbivory plant–insect interactions end-Cretaceous extinction
Footnotes

Received July 16, 2009.
Accepted August 25, 2009.
© 2009 The Royal Society

The Proceedings of the Royal Society B

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