As trepadeiras apresentam uma grande diversidade de espécies e desempenham um importante papel no funcionamento dos ecossistemas, sobretudo em regiões tropicais. Evidências de que as trepadeiras lenhosas (lianas) estariam aumentando em dominância, trazendo sérias conseqüências para a dinâmica florestal, tornam o estudo de padrões de distribuição de espécies em diferentes escalas e de atributos associados às trepadeiras, temas de grande interesse na ecologia. No presente estudo, mostrou-se que as trepadeiras com raízes adesivas têm maior probabilidade de ocorrer em sítios com níveis mais elevados de precipitação e com menor estacionalidade de chuvas, o que contrasta com o padrão global conhecido para lianas. A diversidade e a distribuição de trepadeiras em regiões extratropicais também foram abordadas, considerando a região extratropical da América do Sul. As floras de áreas subtropicais e temperadas diferiram quanto à riqueza e à composição de espécies trepadeiras e quanto a atributos, tais como forma de crescimento e mecanismo de escalada. No sul do Brasil, uma caracterização mais detalhada da composição de espécies de trepadeiras foi realizada, corroborando a importância desse grupo em regiões extratropicais. Finalmente, em escala local, foi demonstrado que a probabilidade de ocorrência das espécies em certo hábitat é influenciada pelo tipo de mecanismo de escalada adotado. Considerando que espécies com o mesmo mecanismo apresentam tolerâncias e requerimentos ambientais semelhantes, a ação de filtros resulta em uma distribuição não randômica das guildas de escalada ao longo de hábitats distintos. Além da estrutura fenotípica, a estrutura filogenética das comunidades refletiu a ação de filtros sobre o mecanismo de escala. / Climbers are a diverse group of plants which plays an important role in ecosystems functioning, especially in tropical regions. Regarding the evidences that lianas are increasing in dominance with significant consequences for the forest dynamics, the study of patterns of distribution at different scales and climbing traits constitute relevant issues in plant ecology. At the present study, we showed that root-climbers have greater probability of occurrence at sites with higher precipitations and lower seasonality, which contrasts with the global pattern proposed for lianas. The diversity and distribution of climbing plants in extratropical regions were also addressed, concerning the extratropical region of South America. Subtropical and temperate areas differed as their species richness, taxonomic composition and attributes, such as growth form and climbing mechanism. In southern Brazil, the climbing flora composition was described in more detail, reinforcing the importance of this group of plants in extratropical regions. Finaly, at local scale, we showed that the species probability of occurrence in a habitat was associated to their climbing mechanism. Regarding that species which share the same climbing mechanism have similar tolerances and environmental requirements, the action of filters results in a non-random distribution of the climbing guilds across different habitats. Besides of the phenotypic structure, the community phylogenetic structure is also influenced by habitat filtering of climbing mechanisms.

Submitted by (edna.saturno@ufrpe.br) on 2016-07-04T15:05:36Z No. of bitstreams: 1 Suellem Gomes Brayner.pdf: 663746 bytes, checksum: 8d3c2e49906ff30da1805ed4af222d6a (MD5) / Made available in DSpace on 2016-07-04T15:05:36Z (GMT). No. of bitstreams: 1 Suellem Gomes Brayner.pdf: 663746 bytes, checksum: 8d3c2e49906ff30da1805ed4af222d6a (MD5) Previous issue date: 2007-02-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This paper analyze the taxonomy and distribution of the Genus Caulerpa in the coast of Pernambuco (07º30’S and 09º00’W) and in the Archipelago of Fernando de Noronha (03º51’S and 32º25’W). Sampling was carried out at the coast of Pernambuco from April/2004 to November/2005, in the intertidal zone of 32 beaches. In Fernando de Noronha collections were made in June/2006 in the intertidal and infralittoral (10, 15 and 21m depth) regions of eight beaches. Exsiccates of Caulerpa from the Professor Vasconcelos Sobrinho Herbarium (PEUFR) were also examined. The results showed that the Genus Caulerpa is represented in the coast of Pernambuco State by 16 infrageneric taxa and some species presented restricted distribution such as: C. kempfii Joly & Pereira, C. lanuginosa J. Agardh and C. serrulata (Forssk.) J. Agardh.. To Fernando de Noronha Archipelago it was registered three infrageneric taxa. In both studied localities the highest species diversity occurred on sandy substrate. / Este trabalho analisa a taxonomia e distribuição do gênero Caulerpa na costa de Pernambuco (07º30’ S e 09º00’ W) e no Arquipélago de Fernando de Noronha (03º51’ S e 32º25’ W). As coletas foram realizadas na costa de Pernambuco de abril/2004 a novembro/2005, na região entre-marés, de 32 praias. Em Fernando de Noronha as coletas foram feitas em junho/2006, na região entre marés e no infralitoral ( 10, 15 e 21 m de profundidade) de oito praias. Foram, também, analisadas as exsicatas de Caulerpa depositadas no Herbário Professor Vasconcelos Sobrinho (PEUFR) da Universidade Federal Rural de Pernambuco. Os resultados mostram que o gênero Caulerpa está representado na costa de Pernambuco, por 16 táxons infragenéricos e algumas espécies apresentaram uma distribuição restrita como C. kempfii Joly & Pereira, C. lanuginosa J. Agardh e C. serrulata (Forssk.) J. Agardh. Para o Arquipélago de Fernando de Noronha foram registrados três táxons infragenéricos. Em ambas localidades estudadas a maior diversidade de espécies ocorreu em substrato arenoso.

The work establishes the ecological importance of shale bings at both a local and global scale by presenting the mechanisms and processes of succession. The bings are postindustrial spoil heaps, the result of retorting mineral oil from deep-mined carboniferous shale beds. The structure of vegetation on the shale bings was determined by a review of published data and a base-line survey of eight bings resulting in new floristic and environmental data from 340 quadrats and 261 plant species. The floristic data were analysed in the context of ecological indicator values (Ellenberg), functional type (competitive, stress-tolerant, ruderal), National Vegetation Classification and two-way indicator species analysis. The results indicated considerable variation in plant communities both between and within different bing sites. The vegetation patterns were associated with the physical (altitude, aspect, slope and bare ground) and chemical (pH, calcium, phosphorous, potassium, magnesium, and nitrogen) environment of the shale substrate. Multivariate analyses (Detrended Correspondence Analysis and Canonical Correspondence Analysis) were used to ascertain the amount of species variation explained by each of the different environmental gradients. Although these abiotic environmental factors were shown to have a statistically significant influence on the plant community structure around 75% of the variation was still unaccounted for. Nine species were selected to determine whether inherent plasticity within a species (plant height, number of flowering heads and seeds produced), the influences of seed dynamics and plant physiology could account for the variation in community structure not explained by environmental variables. This showed that almost half of the variation between and within bing sites was stochastic and probably dependent on the chance arrival of propagules in the initial stages of succession. The results from this study were compared and contrasted with theoretical successional models and with similar studies of primary successions on both natural (glaciers, sand dunes, islands in fresh water, coral islands and volcanoes) and man-made (china clay, coal, other post-industrial sites, urban waste and arable land) sites. The similarities established the relevance of the work to other regions and sites, to successional theory and to ecological restoration and management practices. On a local scale the bings are shown to have high ecological importance. They are refugia for locally rare fauna and flora and are a major component of the West Lothian biodiversity action plans. They are also of considerable social and historic importance.

In order to combat the loss of valuable wetland functions and services, federal, state and tribal governments must have the tools to accurately assess and monitor the condition of wetland ecosystems. One particular method of wetland assessment is Floristic Quality Assessment (FQA), which has been growing in popularity throughout the United States since its creation in the 1970s. FQA relies on vegetative indicators of human disturbance to assess the integrity of an ecosystem. FQA calculations are based on Coefficients of Conservatism (C-scores), professionally-assigned scores ranging from 0-10 that denote a local species' tolerance to anthropogenic disturbance. Despite increasing interest in the use of FQA, few studies have thoroughly tested the performance of FQA, especially in New England. We used the Conservation Assessment and Prioritization System (CAPS), a landscape-based, coarse-scale assessment method, as a basis for evaluating FQA's performance in Massachusetts's forested wetlands. Our objective was to use CAPS Index of Ecological Integrity (IEI) scores (a form of generalized stressor gradient) to evaluate the performance of a variety of FQA indices (biological condition gradients), using C-scores from 7 states in the Northeast, and 2 ecoregions in Massachusetts. Based on our calculations of r-squared, and Spearman's rank analysis, we determined that FQA and C-scores have a moderate to weak relationship with the CAPS index of ecological integrity. Of the 12 indices and metrics we tested, the index with the strongest relationship to the IEI stressor gradient was mean Coefficient of Conservatism. Based on this research a number of suggestions are proposed for improving FQA as it applies to wetland assessment.

The Greater Cape Floristic Region (GCFR) of South Africa has one of the most biodiverse floras in the world. Although ecological speciation is thought to be a primary mechanism behind diversification in the GCFR, it has recently been hypothesised that non-ecological speciation may have an influential role in driving diversification in the montane “sky islands” of the GCFR, potentially resulting in cryptic species. This work seeks to test the relative importance of ecological versus non-ecological processes in powering speciation at different elevations in the GCFR, and to assess the existence of multiple, range-restricted cryptic species at high elevations. The Cape grass genus Ehrharta is an ideal system in which to investigate these processes, as it contains low-, mid-, and high-elevation lineages, with a previously documented adaptive radiation in the succulent karoo. Population-level phylogenetic analyses using targeted enrichment sequencing data show that E. rupestris and E. setacea, as currently defined, are polyphyletic, and reveal multiple distinct monophyletic lineages within the Ramosa, Rehmannii and Setacea clades of genus Ehrharta. Analysis of genotyping-by-sequencing and morphological data, together with evidence of sympatry, confirm these lineages to be distinct entities, resulting in 13 to 16 putative new species, of which several can be considered cryptic. The crown node of Ehrharta is found to have originated 28 Ma, which substantially antedates previous age estimates. Comparisons of morphological evolutionary rates, as well as rates of nonsynonymous to synonymous sequence evolution (��), provide little evidence to support the hypothesis that non-ecological processes have been more important at high elevations. Both the low- and high-elevation clades show evidence of divergent ecological selection, with the Lowlands clade exhibiting high functional trait variance, and the high-elevation Setacea clade showing subtle ecological differentiation and accelerated rates of morphological evolution and �� relative to the rest of Cape Ehrharta. It is instead suggested that diversification in the Cape Ehrharta is triggered by a combination of intrinsic and extrinsic factors unique to each clade, thus corroborating a growing body of research arguing that it is simplistic to generalise radiations as ‘adaptive’ or ‘non-adaptive’. Instead, mountain radiations require an integrated approach to untangle the subtle interaction of geographic, ecological and biological factors that drive diversification.

Philosophiae Doctor - PhD / The family Amaryllidaceae is widely distributed in the southern hemisphere. Members of the family are well known for their content of pharmacologically active alkaloids and represent an important epicentre of Amaryllidaceae-alkaloid diversity. Other metabolites from Amaryllidaceae, such as phenolics including flavonoids, lignans, chromones, and acetophenones, in addition to terpenoids and ceramides have been reported. Boophone haemanthoides (BHE), Crossyne flava (CRO), Clivia miniata (CME) and Nerine humilis (NHE) are members of Amaryllidaceae that have shown biological activity. Parkinson’s disease (PD) is a neurodegenerative disease that progresses with increasing age and some of its major symptoms include tremors, postural and movement related difficulties. To date, the treatment of PD remains a challenge because available drugs only treat the symptoms of the disease or possess serious side effects. In light of this, new treatment options are needed, hence this study investigates the neuroprotective effects of BHE and CRO along with the isolated compounds of BHE and CRO. / 2022

Thesis (MSc)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: The aim of this study was to determine how P nutrition affects biological nitrogen fixation (BNF) via effects on the N2-fixing bacteria in the nodules of Virgilia species native to the Cape Floristic Region (CFR), South Africa. This was evaluated in 3 separate studies: The first study aimed to determine how phosphorus deficiency affects N nutrition of two legume tree species from the Mediterranean Fynbos ecosystem. This study showed that during prolonged P deficiency, V. divaricata maintained a constant biomass, while V. oroboides showed a decreased biomass. V. oroboides showed a decrease in nutritional concentrations, which resulted in the decrease of symbiotic nitrogen fixation (SNF). Both plants utilized atmospheric N more efficiently per nodule under P deficiency. Maximum photosynthesis decreased in V. oroboides, while V. divaricata maintained its photosynthesis. Both species also had greater carbon construction costs during P deficiency. V. divaricata showed clear adaptive features during P-deficiency, as it maintained its growth respiration. The two legume species appear to have different adaptations to P deficiency, which may influence their performance and distribution in their naturally low P environment. The second study aimed to evaluate if soil environmental conditions and mineral nutrient concentration play a major role in microbial communities in plant rhizosphere and nodulation during N2 fixation in legumes. Therefore this study firstly aimed to determine the composition of the N2 fixing bacterial population in the rhizosphere and nodules of V. divaricata. Secondly, it aimed to determine the contribution of these bacteria to N2 fixation during conditions of P deficiency in the Fynbos environment. In the study, the effects of phosphate (P) nutrition on N2 fixing bacterial community structures in Virgilia divaricata rhizosphere and nodules were examined in a pot experiment. V. divaricata were germinated in Fynbos soil as natural inoculum, transferred to clean sand cultures and supplied with 500 μM P and 5 μM P. The N2 fixing bacterial communities in the rhizosphere and nodules were examined based on the PCR-DGGE banding patterns of 16S rDNA and sequencing methods. The GenBank blast results revealed that V divaricata was efficiently nodulated by a wide range of root-nodule bacterial strains, including Burkholderia phytofirmans, Burkholderia sp. and Bradyrhizobium sp. during low P supply. The 15N natural abundance data also confirmed that 40-50% of the N nutrition was acquired through symbiotic N2 fixation. This is not only evidence of nodulation, but also an indication of the adaptation of a range of N2 fixing bacterial strains / species to the nutrient poor, sandy, acidic soil of the Mediterranean-type ecosystems of the Fynbos. The third study examined the physiological effects, such as N2 fixation parameters, plant dependence on N2 fixation, N preference, legume plant growth, carbon costs and amino acid biosynthesis during P deficiency and mineral N supply as NH4NO3 in a slow-growing, Fynbos legume tree, Virgilia divaricata. Continued application of NH4NO3 to the legume plant showed a greater increase in plant dry matter compared to plants with two nitrogen sources (mineral N and atmospheric N2) or plants that relied on atmospheric N2 fixation. Carbon construction costs were more pronounced in plants supplied with two N sources and during P deficiency. Maximum photosynthetic rates per leaf area increased during prolonged P deficiency, irrespective of the N sources. Though plants nodulated, plant dependence on N2 fixation decreased with the addition of NH4NO3. Roots and nodules of the P deficient plants showed an increase in asparagine content, most strikingly so in plants treated with a single source of N. These studies reveal that different legume species of the same genus, may employ contrasting adaptations in order to maintain N nutrition under P deficiency. / AFRIKAANSE OPSOMMING: Die doel van hierdie studie was die bepaling van die wyse waarop fosfaat (P) voeding die biologiese stikstof binding (BNF) deur middel van die effek op N2-bindingsbakterië in die wortelknoppies van Virgilia spesies wat inheems tot die Kaap floraryke area (CFR), Suid Afrika is, affekteer. Drie aparte eksperimente is uitgevoer om die doel te evalueer: Die eerste studie het gepoog om te bepaal hoe 'n fosfaat tekort N voeding van twee peulplant spesies van die Mediterreense Fynbos ekosisteem affekteer. Hierdie studie het getoon dat V. divaricata 'n konstante biomassa tydens verlengde P tekort behou, terwyl V. oroboides ‟n verlaagde biomassa getoon het. V. oroboides het 'n verlaging in voedingskonsentrasies getoon, wat tot 'n verlaging in simbiotiese stikstof binding (SNF) gelei het. Beide plante benut atmosferiese N meer doeltreffend per nodule tydens P tekort. Die maksimum fotosintese in V. oroboides het afgeneem, terwyl V. divaricata sy fotosintese gehandhaaf het. Beide spesies het ook 'n groter koolstof konstruksie koste tydens P tekort gehad. V. divaricata toon duidelike aanpassingsmeganismes tydens P-tekort, aangesien hierdie species sy groei respirasie konhandhaaf. Dit wil voorkom asof die twee peulplant spesies verskillend aangepas is vir P tekort, wat hulle producksie en verspreiding in hulle natuurlike lae P omgewing mag beïnvloed. Die doel van die tweede studie was om te bepaal of grond omgewingskondisies en minerale voedingskonsentrasie 'n belangrike rol speel in die mikrobiese gemeenskappe in die plant risofeer en wortelknoppie vorming tydens N2 binding in peulgewasse. Eerstens het die studie dus gepoog om die samestelling van die N2 bindende bakteriële populasie in die risosfeer en die wortelknoppies van V. divaricata te bepaal. Ten tweede, is die bydrae van die bakterië tot N2-binding tydens P tekort kondisies in die Fynbos omgewing bepaal. In die studie is die effek van fosfaat (P) voeding op die N2-bindende bakteriële gemeenskapstrukture in die Virgilia divaricata risofeer en wortelknoppies in 'n pot eksperiment ondersoek. V. divaricata sade is in fynbos grond as 'n natuurlike inokulum ontkiem, waarna dit na skoon sand kulture oorgedra is en van 500 μM P en 5 μM P voorsien is. Die N2-bindende bakteriële gemeenskappe in die risofeer en wortelknoppies is op grond van die PCR-DGGE band patrone van die 16S rDNA en volgorde bepalingsmetodes ondersoek. Die GenBank Blast resultate het getoon dat V. divaricata doeltreffend deur 'n wye reeks wortel-wortelknoppie bakteriële stamme genoduleer is, insluitende insluitende Burkholderia phytofirmans, Burkholderia sp. en Bradyrhizobium sp. tydens lae P toediening. Die natuurlike 15N voorkoms data het ook bevestig dat 40-50% van die N voeding deur simbiotiese N2 binding bekom is. Dit dien nie net as bewys vir wortelknoppie vorming nie, maar ook 'n aanduiding van die aanpassing van 'n reeks N2 bindende bakteriële stamme/ spesies tot die voedingsarme, sanderige, suur grond van die Mediterreanse ekosisteem van die Fynbos. Die derde studie het die fisiologiese effekte soos bv. N2 fikserings faktore, die afhanklikheid van plante op N2 fiksering, N voorkeur, peulgewas groei, koolstof kostes en aminosuur biosintese tydens P tekort en minerale N toediening soos NH4NO3 in 'n stadig-groeiende, Fynbos peulgewasboom, Virgilia divaricata ondersoek. Volgehoue toediening van NH4NO3 aan die peulplant toon 'n groter toename in plant droë weefsel. Tydens P tekort is die koolstof bou koste meer verhoog in plante wat met twee N bronne voorsien is. Tydens verlengde P tekort het die maksimum fotosintese tempo per blaaroppervlakte toegeneem, ongeag die N bron. Alhoewel die plante wortelknoppies gevorm het, het die plant se afhanklikheid van N2 binding tydens die toediening van NH4NO3 afgeneem. Wortels en wortelknoppies van die P tekort plante het 'n toename in asparagien inhoud getoon, veral in die plante wat met 'n enkele bron van N behandel is. / The DST/NRF-Center of Excellence for Tree Health and Biotechnology, based at the University of Pretoria, for their financial support

Thesis (MSc)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Research into the patterns and drivers of insect diversity in the Cape Floristic Region (CFR) lags far behind that of plants. Here I sample insect herbivore communities on a dominant plant family (Restionaceae), and use a spatially nested sampling design and network analysis to evaluate the association between plant and insect diversity in the CFR. I find that plant species richness predicts insect richness better than environmental factors. Turnover in insect communities is strongly associated with turnover in plant (both species and phylogenetic) communities at both local and regional sampling scales, suggesting insect host specificity. Plant communities unsurprisingly show significant turnover at small spatial scales (i.e. communities situated 0.1-3 km apart show significant turnover and may be tied to ecological niches). Insects show a similar pattern, but the decrease in community overlap is more gradual, suggesting many insects can utilise multiple (possibly closely related) hosts while plants are tied to particular niches. The emergent structure of multiple interaction networks is spatially and temporally invariant, despite high compositional change. However, the internal structure of the networks shows variation (i.e. interactions show spatial and temporal turnover). Seasonal interaction turnover is driven by a turnover in herbivores and by herbivore host switching. Spatially the turnover in interactions is driven by simultaneous turnover in both plants and insects, either suggesting that insects are host specific, or that both groups exhibit parallel responses to environmental gradients. Spatial interaction turnover is also driven by a turnover in plants, showing that many insects can utilise multiple (possibly closely related) hosts and have wider distribution ranges than their host plants. Results point toward insect host specificity, but probably not at the species level, as the primary mechanism structuring insect communities associated with the Restionaceae in the CFR. / AFRIKAANSE OPSOMMING: Navorsing wat verband hou met die patrone en meganismes wat insekdiversiteit in the Kaapse Blommeryk (KBR) hou nie pas met dié van plante nie. In hierdie studie neem ek insekmonsters binne een van die dominante plantfamilies (Restionaceae), en gebruik ‘n ruimtelik geneste ontwerp en netwerkanalise om die verbintenis tussen plant- en insekdiversiteit te evalueer. Ek vind plantrykheid voorspel insekrykheid beter as enige omgewingsfaktore. ‘n Omset in in insekgemeenskappe is sterk verbind aan ‘n omset in plantgemeenskappe (beide spesie en filogenetiese) by beide plaaslik en vir die hele streek. Hierdie dui op insekgasheerspesifisiteit. Plantgemeenskappe wys omset teen kort ruimtelike skale (0.1-3 km). Insekte wys ‘n soortgelyke patron, maar die afname in oorvleueling tussen gemeenskappe is meer geredelik. Dit dui dat insek meer as een gasheer kan gebruik, terwyl plante streng tot sekere nisse verbind is. Die ontluikende struktuur van menigde interaksienetwerke wys geen ruimtelike of tydelike variasie nie, ten spyte van hoë gemeenskapsomset. Nietewel, die interne struktuur van die netwerke wys veranderinge (interaksies in netwerke wys omset). Seisonale interaksie-omset kan toegeskryf word aan ‘n omset van herbivore en insekgasheerverandering. Ruimtelike interaksie-omset word toegeskryf aan gelyktydige insek- en plantomset, wat óf deur insekgasheerspesifisiteit veroorsaak word óf deur parallele reaksies tot omgewingsveranderinge. Ruimtelike interaksie-omset word ook deur plantomset beïnvloed, wat aandui sommige insekte kan meer as een gasheer benut en insekte het weier verspreidings as hul gasheer. Resultate dui daarop dat insekgasheerspesifisiteit, maar waarskynlik nie op die spesievlak nie, moontlik die primêre meganisme is wat insekgemeenskappe verbind aan die Restionaceae in die KBR struktureer.

Thesis (PhD (Botany and Zoology))--University of Stellenbosch, 2010.

Thesis (PhD (Botany and Zoology))--Stellenbosch University, 2011. / ENGLISH ABSTRACT: With the current global decline in pollinators, and the concurrent decline in plant species, pollination research is becoming increasingly important. However, studies outside Europe and North-America and on groups other than insects are needed to make generalisations possible. In this thesis I study how pollination structures plant and bird communities in a biodiversity hotspot, the Cape Floristic Region of South Africa. I show that bird-plant pollination mutualisms are an important ecological factor structuring ornithophilous Proteaceae and nectar-feeding bird communities. This close association between plant and bird communities suggests an important role for community wide pollination mutualisms. How these mutualisms disassemble in reaction to a range of anthropogenic impacts is determined. Firstly, I use experimental manipulation of honeybee density to test whether honeybee farming affects nectar-feeding birds. Hive addition increased honeybee abundance far above natural levels but nectar-feeding bird pollinators were not consistently affected. Secondly, I document the impact of a two lane tar road on the bird pollination community. The two-fold decline found in pollination along roadsides, should have important implications for the way we view and manage road verges for ecological processes. Thirdly, I investigated how fragmentation affects bird-pollination communities by assessing an endangered, bird-pollinated plant, Brunsvigia litoralis. The only flower visitor at the urban sites, the shorter billed Greater Double-collared Sunbird is unable to access the nectar due to a long perianth tube. The longer billed Malachite Sunbird was the sole pollinator of B. litoralis at the rural site, significantly increased seed set. The lack of ecological analogs in these urban fragments might place pollinator specialist plants, such as B. litoralis, at risk. Fourthly, fire is a frequent disturbance in communities of bird-pollinated plants. In a before/after fire observation study and a burnt/unburnt transplant study, birds visited flowers in the “before fire” and “unburnt” areas only. The results are surprising given the large number of bird-pollinated plants flowering in the early post-fire vegetation. Lastly, I find that alien invasive plant species are incorporated into the native pollination community in a spectacular way; sunbirds adapt to a hummingbird-like, hovering lifestyle to obtain nectar. Alien invasive plants greatly increase nectar-feeding bird abundance; in turn, birds enhance seed set in these alien plants. I conclude by asking whether the disassembling of bird pollination communities really matters. To answer this question I report on a decade of demographic data on the geophytic bird-pollinated Brunsvigia orientalis. In the demographic analysis, the elasticity component for reproduction was more important than expected for a long lived plant. Reduced population growth in the shade and a large investment in a winged inflorescence, suggest B. orientalis is a light demanding, well dispersed, gap colonising species. The link between pollination and seed has been made before, but I take this one step further and show that pollination intensity predicts population growth rate. By linking plant demography and pollination, I was able to predict the future of plant populations under variable pollination conditions. The disassembly of bird pollination communities only becomes important for population persistence once the mutualism has almost entirely broken down. / AFRIKAANSE OPSOMMING: Met die huidige globale afname in bestuiwers en die gelyktydige afname in plant spesies, word bestuiwing navorsing toenemend belangrik. Studies buite Europa en Noord-Amerika en op groepe anders dan insekte is nodig on veralgemenings moontlik te maak. In hierdie tesis bestudeer ek hoe bestuiwing struktuur gee and plant en voël gemeenskappe in 'n biodiversiteit hotspot, die Kaapse Floristiese Ryk van Suid-Afrika. Ek wys dat voël-plant bestuiwings mutualismes 'n belangrike ekologiese faktor is in die strukturering van voël bestuifde Proteaceae gemeenskappe en nektar-etende voël gemeenskappe. Hierdie noue assosiasie tussen plant en voël gemeenskappe impliseer 'n belangrike rol vir gemeenskapwye bestuiwings meganismes. Ek bepaal hoe hierdie mutualismes aftakel in reaksie op 'n verskeidenheid van antropogeniese impakte. Eerstens gebruik ek 'n eksperimentele manipulasie van heuningby getalle om te toets of bye boerdery nektar-etende voëls affekteer. Byekorf toevoeging het heuningby getalle laat toeneem tot ver bo natuurlike vlakke maar nektar-etende voël bestuiwers is nie konsekwent beïnvloed nie. Tweedens dokumenteer ek die impakte van 'n twee baan teerpad op die voël bestuiwings gemeenskap. Die twee-malige afname in bestuiwing langs paaie sal belangrike implikasies hê vir die manier hoe ons pad reserwes sien en bestuur met betrekking tot ekologiese prosesse. Derdens bestudeer ek hoe fragmentasie die voël-plant gemeenskappe affekteer deur die bedreigde voël-bestuifde Brunsvigia litoralis te assesseer. Die enigste besoeker in die meer stedelike area, die Groot-rooibandsuikerbekkie, wat 'n korter snawel het, is nie in staat om die nektar te bereik nie, weens 'n te lang blombuis. Die Jangroentjie suikerbekkie met sy langer snawel is die enigste bestuiwer van B. litoralis in die meer landelike area, met 'n betekenisvolle vermeerdering in saad vorming. Die gebrek aan ekologies analogiese spesies in die stedelike fragmente kan 'n risiko inhou vir bestuiwer gespesialiseerde plante soos B. litoralis. Vierdens, vuur is 'n gereelde versteuring van voël-plant gemeenskappe. In 'n voor/na vuur observasie studie en 'n brand/nie-brand verplasing studie, het voëls blomme net in die “voor brand” en “nie-brand” areas besoek. Hierdie resultate is verrassend siende die groot hoeveelheid voël-bestuifde plante wat blom direk na brande. Laastens het ek gevind dat uitheemse indringer plante geïnkorporeer word in die inheemse bestuiwers gemeenskappe op 'n skouspelagtige manier; suikerbekkies pas aan tot 'n kolibri-tipe, fladderende lewenswyse om nektar te bekom. Uitheemse indringer plante het nektar-etende voël hoeveelhede laat toeneem; in reaksie het voëls saad opbrengs vermeerder. In konklusie vra ek of hierdie aftakeling van die voël bestuiwers gemeenskap belangrik is. Om hierdie vraag te antwoord assesseer ek 'n dekade van demografiese data van die geofietiese, voël-bestuifde plant, Brunsvigia orientalis. In die demografiese analises was die elastisiteit komponent van reproduksie belangriker as verwag vir 'n langlewende plant. Verminderde populasie groei in die skaduwee en 'n hoë investering in 'n gevlerkte bloeiwyse suggereer dat B. orientalis 'n lig afhanklike, goed verspreide, gaping koloniserende spesie is. Die skakel tussen bestuiwing en saadvorming is voorheen gemaak, maar ek neem dit een stap verder en wys dat bestuiwings intensiteit populasie groeikoers voorspel. Deur plant demografie en bestuiwing te koppel was ek in staat om die toekoms van populasies onder variërende bestuiwings kondisies te voorspel. Die aftakeling van voël bestuiwings gemeenskappe word slegs belangrik vir populasies se voortbestaan wanneer die mutualisme amper heeltemal verdwyn het.