Ecosystem engineering in fragmented forests [Elektronische Ressource] : edge-mediated hyper-abundance of leaf-cutting ants and resulting impacts on forest structure, microclimate and regeneration / vorgelegt von Sebastian Tobias Meyer

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• Publié par: technische_universitat_kaiserslautern
• Publié le: 01 janvier 2008
• Nombre de lectures: 30
• Langue: English
• Poids de l'ouvrage: 4 Mo

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D 386


Ecosystem engineering
in fragmented forests
Edge-mediated hyper-abundance of leaf-cutting ants
and resulting impacts on forest structure,
microclimate and regeneration




vom Fachbereich Biologie der Universität Kaiserslautern
zur Verleihung des akademischen Grades „Doktor der
Naturwissenschaften“ genehmigte Dissertation



vorgelegt von Sebastian Tobias Meyer











Betreuer der Dissertation: Prof. Dr. Burkhard Büdel / Dr. Rainer Wirth
2. Gutachter: Prof. Dr. Flavio Roces (Universität Würzburg)
3. Gutachter: Prof. Dr. Marcelo Tabarelli (Universität Recife, Brasilien)
Vorsitz der Prüfungskommission: Prof. Dr. Dr. h.c. Helmut J. Schmidt


Tag der Wissenschaftlichen Aussprache: 20. November 2008
I




… answers to the key questions would come hard.
Everything is complicated. Species respond to
fragmentation in idiosyncratic and unexpected ways,
some of the latter representing novel physical and
biological phenomena. Every species, it turns out,
really is connected to everything else, …

Edward O. Wilson

In his forword to “Lessons from Amazonia”, which synthesizes
20 years of experimental fragmentation research in the Brazilian
Amazon.
III

Preface




The book at hand is a cumulative doctoral thesis UFPE) and is coordinated by Marcelo Tabarelli.
written at the University of Kaiserslautern, Ger- The objective of the project is to develop and
many in the department of Plant Ecology and implement management regimes for natural
Systematics (Prof. Dr. Burkhard Büdel). The resources that guarantee the protection of biodi-
results presented are based mainly on research versity and the integrity of the Atlantic Forest
conducted in the Brazilian Atlantic Forest be- within the holding of the Usina Serra Grande.
tween 2005 and 2008 as part of an ongoing re- Thereby, the project aims to develop a regional
search cooperation of Dr. Rainer Wirth (Depart- model for sustainable development and use of
ment of Plant Ecology and Systematics, Univer- natural resources in the area. Within the frame-
sity of Kaiserslautern) with Prof. Dr. Inara R. work of the Projeto Serra Grande a range of
Leal and Prof. Dr. Marcelo Tabarelli (Depart- often interconnected research projects are inte-
ment of Botany, Universidade Federal de Per- grated, which describe the local diversity of
nambuco, Recife, Brazil). Included are also re- various species groups and investigate ecosystem
sults of some additional experiments conducted functioning in the heavily fragmented Atlantic
in the laboratories at the University of Kaisers- Forest. Central results have been published in a
lautern. This thesis is integrated into the “In- book describing the species composition of the
TroFF-Project” which comprises a central part of Atlantic Forest of Northeast Brazil (Pôrto et al.
the research conducted within the framework of 2005. Diversidade Biológica e Conservação da
the “Projeto Serra Grande”. Floresta Atlântica ao Norte do Rio São
Francisco. Ministério do Meio Ambiente
PROJETO SERRA GRANDE: Conservando o Brasília, Brasil) and can be accessed on the web-
melhor do Centro de Endemismo Pernambuco. site of CEPAN (http://www.cepan.org.br/)
The Projeto Serra Grande was initiated in 2001 Among the specific research projects integrated
by the Center of Environmental Research in into Project Serra Grande is “InTroFF”.
Northeast Brazil (Centro de Pesquisas Ambien-
tais do Nordeste, CEPAN). The ongoing project INTROFF (Interações troficas em florestas frag-
is a joint venture of CEPAN, the Usina Serra mentadas) - This project (coordinated by Inara
Grande (a privatly owned sugar cane plantation) Leal and Rainer Wirth) examines the conse-
and the University of Pernambuco in Recife, quences of habitat fragmentation on food webs
Brazil (Universidade Federal de Pernambuco, using the trophic cascade plant - fungus/leaf-
V
VI Ecosystem engineering in fragmented forests

cutting ant - predator/parasite as a model system. nest densities in fragmented forest habitats on
The consequences of habitat fragmentation on microclimate and forest regeneration, which is
food webs had been completely neglected in part of the present thesis.
fragmentation related research in the past, al-
though the importance of trophical interactions THE PRESENT THESIS is organized into five
for local species coexistence and biodiversity is major sections: “Setting the scene”, “Atta in a
increasingly acknowledged. The underlying fragmented forest”, “Bottom up control of Atta”,
causes for an increase of leaf-cutting ant densi- “Nest effects of Atta cephalotes”, and a conclud-
ties with increasing habitat disturbance were ing “Synthesis”. In the first section the reader is
assessed in a doctoral thesis by Pille Urbas introduced into the theory and basics underlying
(2001-2004), which identified control by both this thesis followed by a review of the response
resource availability (bottom-up forces) and of herbivores to fragmentation and forest edge
predation and parasitism (top-down forces) to be creation. Chapters on Atta in a fragmented forest
less effective in fragmented compared to conti- will present spatial and temporal patterns of leaf-
nuous forests. cutting ant densities in a fragmented forest fol-
The project has focused in the beginning on lowed by a chapter on a possible bottom-up
fragmentation induced changes in the behavior mechanism controlling Atta densities. The forth
and ecology of leaf cutting ants and has been section will cover the effects leaf-cutting ant
extended in 2005 to incorporate the complemen- nests have on forests. The thesis concludes with
tary view with a focus on effects of leaf-cutting a synthesis of the findings of this thesis about
ants in a fragmented forest. Specifically, we interaction effects of forest fragmentation and
study the consequences of high leaf-cutting ant leaf-cutting ants.












Acknowledgements




This thesis would not have been possible without numerous people to whom I am deeply grateful for their
help, support and encouragement throughout the last years.
First of all, I want to thank my orientadores Rainer Wirth, Inara Leal and Marcelo Tabarelli who were a
constant inspiration during my doctoral thesis. I am grateful for their support, encouragements, advice
and the insights I gained while working with them. Last but not least, I am thankful for the trust they have
placed in me when giving me the chance to work on a project as big and integrated as this thesis.
Burkhard Büdel and all the people from the Department of Plant Ecology and Systematics for the oppor-
tunity to work in a great lab group, for fruitful discussions and lots of shared cheerful moments. Thank
you Antje, Bea, Betty, Frank, Fritz, Hans, Natalie, Ms. Scheffler, Steffi, Tanja, Wolf-Rüdiger!
Flavio Roces for his willingness to participate in the examination committee and Helmut Schmidt for
taking the time to be the committee chairman.
Manoel Vieira Araújo Jr. for his invaluable help during my time in Brazil when fighting with language,
logistics and the always difficult conditions on a field station in the middle of nowhere.
Meike Passlack for her enthusiasm during her diploma project and Christoph Dohm, Simone Jürgens, and
Jörg Stephan during their assistantships in Serra Grande. Thank you all for your help in the field getting
various projects going and collecting data. I hope you had a time in Brazil as good as I did.
Marcondis und Alexandre† for their help determining plant species and seeds from Serra Grande and all
the Brazilian students with whom I had the opportunity to live, work and also relax. A big thank you to
Andre, Bill, Gabi, Manoel, Patricia, Paulinho, Ursula, Vera, Walkiria, Wanessa, Zezinho, and especially
Janaina. Marinalva and her husband Caitano for being a reliable base in Ibateguara and helping out when
ever there was need.
Rafael for his support during the last months of writing it all up, Britta and Alexandra for their friendship,
and the ultimate frisbee team of Kaiserslautern for getting me away from the computer and exercising in
fresh air. Last but not least I want to thank my family; my parents Cornelia and Eberhard for giving me
the freedom to live my dreams and my sister Sandra for always being there.
VII
VIII Ecosystem engineering in fragmented forests





Financial and logistic support for this study was received by several agencies.

The central workshop of the University of Kaiserslautern helped to plan and constructed radiation shields
for measuring equipment and the electronics workshop of the university designed and built amplifiers that
were essential for the successful microclimatic measurements presented in this study.

Grants financing the