Seed dispersal ecology of Leonia cymosa (Violaceae) in the rain forest of Eastern Ecuador [Elektronische Ressource] / vorgelegt von Albrecht Pfrommer

Albrecht Pfrommer

Sujets

• Biologie

Informations

• Publié par: julius-maximilians-universitat_wurzburg
• Publié le: 01 janvier 2009
• Nombre de lectures: 20
• Langue: English
• Poids de l'ouvrage: 2 Mo

Extrait

Seed dispersal ecology of Leonia cymosa (Violaceae) in
the rain forest of Eastern Ecuador



Dissertation zur Erlangung
des naturwissenschaftlichen Doktorgrades
der Bayerischen Julius-Maximilians-Universität Würzburg




vorgelegt von
Albrecht Pfrommer
aus Frankfurt



Würzburg, 2009












Eingereicht am:............................................................................
Mitglieder der Promotionskommission:
Vorsitzender:................................................................................
1. Gutachter: Prof. Dr. K. Eduard Linsenmair
2. Gutachter: Prof. Dr. E. Heymann
Tag des Promotionskolloquiums:................................................

Doktorurkunde ausgehändigt am: ..............................................







Contents Pages
1 Introduction ....................................................................................................... 1
2 Study area........................................................................................................... 5
2.1 Location, climate and forest type ........................................................................ 5
2.2 Study plots ........................................................................................................... 6

3 The Protagonists ................................................................................................ 7
3.1 Life history traits of Leonia cymosa ................................................................. 7
3.1.1 Introduction ......................................................................................................... 8
3.1.2 Size distribution and spatial pattern of fruiting trees......................................... 10
3.1.2.1 Methods .............................................................................................. 10
3.1.2.2 Results ................................................................................................ 11
3.1.3 Flowering and fruiting seasons.......................................................................... 13
3.1.3.1 Methods .............................................................................................. 13
3.1.3.2 Results ................................................................................................ 13
3.1.4 Fruit morphology and nutritional quality .......................................................... 14
3.1.4.1 Methods .............................................................................................. 14
3.1.4.2 Results ................................................................................................ 18
3.1.5 Individual fruit production: variation within years and between years............. 27
3.1.5.1 Methods .............................................................................................. 27
3.1.5.2 Results ................................................................................................ 29
3.1.6 Infestation of fruits by insect larvae .................................................................. 34
3.1.6.1 Methods .............................................................................................. 34
3.1.6.1 Results ................................................................................................ 34
3.1.7 Discussion.......................................................................................................... 35

I 3.2 Frugivores of Leonia cymosa in the rain forest of Cuyabeno...................... 41
3.2.1 Introduction ....................................................................................................... 42
3.2.2 Visitors of fruiting trees – species and feeding behavior .................................. 43
3.2.2.1 Methods.............................................................................................. 43
3.2.2.2 Results ................................................................................................ 46
3.2.3 Contribution of frugivores to fruit removal and patterns of use of
L. cymosa by monkeys ...................................................................................... 50
3.2.3.1 Methods.............................................................................................. 50
3.2.3.2 Results ................................................................................................ 51
3.2.4 Discussion ......................................................................................................... 60

4 Interaction of plant and monkeys .................................................................. 71
4.1 Does the quality of fruits of Leonia cymosa (Violaceae) influence fruit
choice by its free ranging reliable seed disperser Saguinus nigricollis
(Callitrichidae)?............................................................................................... 71
4.1.1 Introduction ....................................................................................................... 71
4.1.2 Methods............................................................................................................. 73
4.1.3 Results ............................................................................................................... 76
4.1.4 Discussion ......................................................................................................... 77
4.2 Fruit removal by monkeys from a Neotropical tree: a test of the
fruit crop size hypothesis ................................................................................ 81
4.2.1 Introduction ....................................................................................................... 82
4.2.2 Methods............................................................................................................. 84
4.2.3 Results ............................................................................................................... 89
4.2.4 Discussion ......................................................................................................... 97



II 5 Synopsis .......................................................................................................... 105
6 Summary ........................................................................................................ 119
Zusammenfassung ........................................................................................................... 123
Acknowledgements .......................................................................................................... 129
Appendices ....................................................................................................................... 131
Appendix A ....................................................................................................................... 131
Appendix B........................................................................................................................ 132
Appendix C........................................................................................................................ 134
Appendix D ....................................................................................................................... 135
Appendix E........................................................................................................................ 136
Appendix F ........................................................................................................................ 137



III Chapter 1 – Introduction
1 Introduction
Seed dispersal is a crucial step in plant reproduction. It improves offspring survival
because of escape from mortality caused by density-dependent predation and/or
competition (Janzen 1970; Connell 1971; Harms et al. 2000). Long distance dispersal
events enable species dispersal and colonization of distant habitat, migration of plant
species, and persistence of plant populations in fragmented landscapes (Cain et al. 2000).
Seed dispersal is also seen as a key process in shaping the spatial structure of plant
1populations via the seed shadows and the seed output of individual plants. In the
succession of plant regeneration processes, the so called “seed dispersal loop” (Wang et al.
2
2002), seed-dispersion patterns are determined by the spatial pattern of reproductive
adults, while in the following the pattern of future adults itself is again a result of seed-
dispersion patterns (among other factors, Nathan et al. 2000; Bleher et al. 2002). Seed
dispersal is also important for the maintenance of plant diversity, as indicated by spatially
explicit forest models that simulate a loss of animal dispersers in a tropical rain forest
(Webb and Peart. 2001).
In tropical rain forests, animal-mediated seed dispersal is a common, often the dominating
dispersal mode. Up to 90% of the plants in contemporary rain forests produce fleshy fruits
and depend on fruit or seed removal by frugivores and their ability to reliably disperse the
seeds away from the mother plant (Howe and Smallwood. 1982; Jordano 2000). Seed
dispersal of these plants can only function pro