Floral Biology, Breeding System, Pollination and Reproductive
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Institut für Systematische Botanik und Ökologie Universität Ulm Floral Biology, Breeding System, Pollination and Reproductive Success of Selected Understory Tree Species in Fragments of Atlantic Rainforest in Pernambuco, Northeast Brazil Dissertation zur Erlangung des Doktorgrades Dr. rer. nat. der Fakultät für Naturwissenschaften, Universität Ulm vorgelegt von Marcus Braun aus Bad Segeberg 2010 Amtierender Dekan: Prof. Dr. Axel Groß Erstgutachter: Prof. Dr. Gerhard Gottsberger Zweitgutachter: Prof. Dr. Manfred Ayasse Tag der Promotion: 10.06.2010 2 Table of contents Acknowledgments ................................................................................................6 Summary...............................................................................................................8 Zusammenfassung ..............................................................................................14 1. General Introduction..................................................................................21 1.1 Fragmentation and pollination......................................................................21 1.2 Pollination biology: state of knowledge for the Annonaceae and Violaceae families .........................................................................................................24 1.3 The study area...............................................................................................25 1.4 Aim and outline of the thesis........................................................................25 2. Floral biology, visitor abundance and reproductive success of Anaxagorea dolichocarpa (Annonaceae) in Atlantic forest fragments of Northeast Brazil… ………………… …… ……… . 27 2.1 INTRODUCTION ........................................................................................27 2.2 MATERIAL AND METHODS....................................................................29 2.2.1 Study species and populations...................................................................29 2.2.2 Flower morphology and breeding system..................................................29 2.2.3 Anthesis, scent production and thermogenesis..........................................30 2.2.4 Seed dispersal and germination .................................................................31 2.2.5 Phenology of tree individuals and subpopulations....................................32 2.2.6 Flower visitors, pollinator abundance and fruit set ...................................32 2.3 RESULTS.....................................................................................................33 2.3.1 Flower morphology and breeding system..................................................33 2.3.2 Anthesis and stages of flowering...............................................................34 2.3.3 Floral scent and thermogenesis..................................................................36 2.3.4 Seed dispersal and germination .................................................................37 2.3.5 Flower, bud and fruit production...............................................................40 2.3.6 Flower visitation, fruit set and fragment size ............................................42 2.4 DISCUSSION...............................................................................................44 2.4.1 Flower biology and pollination..................................................................44 2.4.2 Visitor abundance, fragmentation and seed production ............................47 2.4.3 Outlook ......................................................................................................49 3. Who pollinates tropical woody Violaceae? The cases of Paypayrola blanchetiana and Amphirrhox longifolia …… 51 3.1 Introduction...................................................................................................51 3.2 Material and Methods...................................................................................52 3.2.1 Study species .............................................................................................52 3.2.2 Anthesis, floral morphology and P/O ratio................................................53 3.2.3 Scent production ........................................................................................54 3.2.4 Nectar production ......................................................................................55 3.2.5 Breeding system and fruit set ....................................................................56 3.2.6 Flower visitation ........................................................................................56 3.2.7 Pollen germination experiment..................................................................57 3 3.3 RESULTS..................................................................................................... 57 3.3.1 Anthesis, Flower Morphology and P/O Ratio........................................... 57 3.3.2 Floral scent ................................................................................................ 59 3.3.3 Nectar ........................................................................................................ 62 3.3.4 Breeding system and natural fruit set........................................................ 64 3.3.5 Flower visitation........................................................................................ 64 3.3.6 Pollen germination experiment ............................................................... 667 3.4 DISCUSSION .............................................................................................. 67 3.4.1 Flower characteristics and floral visitors .................................................. 67 3.4.2 Fruit set and pollination in P. blanchetiana .............................................. 69 3.4.3 Pollinators of A. longifolia ........................................................................ 70 3.4.4 Are nectar and scent production affected by fragmentation?.................... 72 4. Effect of forest fragmentation and patch flowering intensity on reproductive success of Paypayrola blanchetiana (Violaceae) in the Atlantic rainforest of NE Brazil 73 4.1 INTRODUCTION........................................................................................ 73 4.2 MATERIAL AND METHODS ................................................................... 76 4.2.1 Plant Material ............................................................................................ 76 4.2.2 Flower, fruit and seed sampling ................................................................ 77 4.2.3 Data Analysis ............................................................................................ 78 4.3 RESULTS..................................................................................................... 80 4.3.1 Autocorrelation of plant individuals ......................................................... 80 4.3.2 Plant dbh, flower and fruit production ...................................................... 80 4.3.3 Sub-population flower production and resulting fruit set ......................... 81 4.3.4 Fruits/flower and seeds/ovule ratios (reproductive success) in large and small fragments .................................................................................................. 83 4.3.5 Seeds per fruit in large and small fragments............................................. 83 4.3.6 Influence of predictors on fruit set and seed set........................................ 84 4.4 DISCUSSION .............................................................................................. 86 4.4.1 Resource availability................................................................................. 86 4.4.2 Patch flowering intensity and fruit set....................................................... 86 4.4.3 Pollinator service, low fruit set…and inbreeding ?................................... 87 4.4.4 Fruit and seed production in large and small fragments ........................... 88 4.4.5 Conservation issues................................................................................... 90 5. Fruit production of Cymbopetalum brasiliense (Annonaceae) in the absence of pollinators in an Atlantic forest fragment in NE Brazil 92 5.1 INTRODUCTION........................................................................................ 92 5.2 MATERIAL AND METHODS ................................................................... 93 5.2.1 Study species and population .................................................................... 93 5.2.2 Flowering phenology and fruit production................................................ 94 5.2.3 Anthesis and flower visitors...................................................................... 94 5.2.4 Floral scent and floral thermogenesis........................................................ 95 5.2.5 Breeding system experiments.................................................................... 96 5.3 RESULTS..................................................................................................... 97 5.3.1 Flowering phenology and fruit production................................................ 97 5.3.2 Flower anthesis.......................................................................................... 98 5.3.3 Thermogenesis .......................................................................................... 99 4 5.3.4 Flower Scent ..............................................................................................99