The vegetation of the island of Rangitoto was examined in order to determine the current vegetation pattern and to identify the factors which have influenced the development of this pattern. Information about the order and dates of eruptive events was reviewed to gauge the length of time that the various surfaces of the island have been available as a substrate for the development of a vegetation covering. Available geological information, dating evidence, historical accounts, tree ages, and Maori evidence all point to a single period of eruptive activity, probably only several years in duration, around the mid- to late-1300's (A.D.). The order of eruption was probably production of the ash that covers neighbouring islands, followed by cinder cone building, followed by eruption of the lava flows. The lava flows were found to consist of clinkery aa flows, blocky aa flows, and a flow type referred to as Rangitoto slab flows. These flow types could be partially distinguished from one another, using discriminant analysis, on the basis of the length of the longest fragment on a 5x5m plot and the number of fragments on a lxlm subplot. A new transition sequence of flow types from pahoehoe to aa lavas is proposed for viscous lavas undergoing low rates of shear strain. The vegetation pattern of the lava fields was examine using TWINSPAN and CANOCO analysis of foliage cover percentage information gathered from 125 5x5m plots. It was found to consist of a successional sequence of vegetation arranged in a mosaic. The mosaic was found to relate strictly to the underlying lava flow surface. Large Metrosideros grow in crevices on slab flows and next to large boulders on aa flows. Smaller Metrosideros grow on small slabs on slab flows. Mixed species scrub is found growing on unbroken slab surfaces. The relative rate of colonisation of different types of flows under different climatic conditions was considered. The Metrosideros hybrid swarm was studied using morphometric information. The putative parent species of the swarm were found, using Principal Components Analysis, to be Metrosideros excelsa and Metrosideros robusta. The Rangitoto Metrosideros population was found, using Canonical Variates Analysis, to be the result of hybridisation, followed by introgression towards M. excelsa . The probable F1 hybrids grow in early successional stage vegetation. The major geographical trend is the tendency for backcrossed hybrids to grow on the eastern side of the island, suggesting eastern origins of M. robusta seeds. The impact of browsing animals on the vegetation was studied over five years in exclosures and corresponding control sites. Metrosideros foliage recovered slightly. Griselinia lucida and Cyathodes juniperina seedlings were recruited into the shrub layers in exclosures, but not in control sites. Astelia seedlings also benefitted from the absence of browsing pressure, as did Thelymitra longifolia. The distribution of browsing animal populations in relation to the vegetation pattern was studied using faecal pellet recruitment data gathered by the New Zealand Forest Service in 1984. Both wallabies (Petrogale penicillata penicillata) and possums (Trichosurus vulpecula) were found to be distributed principally according to the amount of palatable foliage available to each species in each vegetation type. / Appendices restricted at the request of the author

The vegetation of the island of Rangitoto was examined in order to determine the current vegetation pattern and to identify the factors which have influenced the development of this pattern. Information about the order and dates of eruptive events was reviewed to gauge the length of time that the various surfaces of the island have been available as a substrate for the development of a vegetation covering. Available geological information, dating evidence, historical accounts, tree ages, and Maori evidence all point to a single period of eruptive activity, probably only several years in duration, around the mid- to late-1300's (A.D.). The order of eruption was probably production of the ash that covers neighbouring islands, followed by cinder cone building, followed by eruption of the lava flows. The lava flows were found to consist of clinkery aa flows, blocky aa flows, and a flow type referred to as Rangitoto slab flows. These flow types could be partially distinguished from one another, using discriminant analysis, on the basis of the length of the longest fragment on a 5x5m plot and the number of fragments on a lxlm subplot. A new transition sequence of flow types from pahoehoe to aa lavas is proposed for viscous lavas undergoing low rates of shear strain. The vegetation pattern of the lava fields was examine using TWINSPAN and CANOCO analysis of foliage cover percentage information gathered from 125 5x5m plots. It was found to consist of a successional sequence of vegetation arranged in a mosaic. The mosaic was found to relate strictly to the underlying lava flow surface. Large Metrosideros grow in crevices on slab flows and next to large boulders on aa flows. Smaller Metrosideros grow on small slabs on slab flows. Mixed species scrub is found growing on unbroken slab surfaces. The relative rate of colonisation of different types of flows under different climatic conditions was considered. The Metrosideros hybrid swarm was studied using morphometric information. The putative parent species of the swarm were found, using Principal Components Analysis, to be Metrosideros excelsa and Metrosideros robusta. The Rangitoto Metrosideros population was found, using Canonical Variates Analysis, to be the result of hybridisation, followed by introgression towards M. excelsa . The probable F1 hybrids grow in early successional stage vegetation. The major geographical trend is the tendency for backcrossed hybrids to grow on the eastern side of the island, suggesting eastern origins of M. robusta seeds. The impact of browsing animals on the vegetation was studied over five years in exclosures and corresponding control sites. Metrosideros foliage recovered slightly. Griselinia lucida and Cyathodes juniperina seedlings were recruited into the shrub layers in exclosures, but not in control sites. Astelia seedlings also benefitted from the absence of browsing pressure, as did Thelymitra longifolia. The distribution of browsing animal populations in relation to the vegetation pattern was studied using faecal pellet recruitment data gathered by the New Zealand Forest Service in 1984. Both wallabies (Petrogale penicillata penicillata) and possums (Trichosurus vulpecula) were found to be distributed principally according to the amount of palatable foliage available to each species in each vegetation type. / Appendices restricted at the request of the author

The vegetation of the island of Rangitoto was examined in order to determine the current vegetation pattern and to identify the factors which have influenced the development of this pattern. Information about the order and dates of eruptive events was reviewed to gauge the length of time that the various surfaces of the island have been available as a substrate for the development of a vegetation covering. Available geological information, dating evidence, historical accounts, tree ages, and Maori evidence all point to a single period of eruptive activity, probably only several years in duration, around the mid- to late-1300's (A.D.). The order of eruption was probably production of the ash that covers neighbouring islands, followed by cinder cone building, followed by eruption of the lava flows. The lava flows were found to consist of clinkery aa flows, blocky aa flows, and a flow type referred to as Rangitoto slab flows. These flow types could be partially distinguished from one another, using discriminant analysis, on the basis of the length of the longest fragment on a 5x5m plot and the number of fragments on a lxlm subplot. A new transition sequence of flow types from pahoehoe to aa lavas is proposed for viscous lavas undergoing low rates of shear strain. The vegetation pattern of the lava fields was examine using TWINSPAN and CANOCO analysis of foliage cover percentage information gathered from 125 5x5m plots. It was found to consist of a successional sequence of vegetation arranged in a mosaic. The mosaic was found to relate strictly to the underlying lava flow surface. Large Metrosideros grow in crevices on slab flows and next to large boulders on aa flows. Smaller Metrosideros grow on small slabs on slab flows. Mixed species scrub is found growing on unbroken slab surfaces. The relative rate of colonisation of different types of flows under different climatic conditions was considered. The Metrosideros hybrid swarm was studied using morphometric information. The putative parent species of the swarm were found, using Principal Components Analysis, to be Metrosideros excelsa and Metrosideros robusta. The Rangitoto Metrosideros population was found, using Canonical Variates Analysis, to be the result of hybridisation, followed by introgression towards M. excelsa . The probable F1 hybrids grow in early successional stage vegetation. The major geographical trend is the tendency for backcrossed hybrids to grow on the eastern side of the island, suggesting eastern origins of M. robusta seeds. The impact of browsing animals on the vegetation was studied over five years in exclosures and corresponding control sites. Metrosideros foliage recovered slightly. Griselinia lucida and Cyathodes juniperina seedlings were recruited into the shrub layers in exclosures, but not in control sites. Astelia seedlings also benefitted from the absence of browsing pressure, as did Thelymitra longifolia. The distribution of browsing animal populations in relation to the vegetation pattern was studied using faecal pellet recruitment data gathered by the New Zealand Forest Service in 1984. Both wallabies (Petrogale penicillata penicillata) and possums (Trichosurus vulpecula) were found to be distributed principally according to the amount of palatable foliage available to each species in each vegetation type. / Appendices restricted at the request of the author

For over a century, the origins and mechanisms underlying the diversification of the enormous cosmopolitan genus Carex (>2,100 species; Cariceae, Cyperaceae or sedge family) have remained largely speculative. Although its unique morphology (e.g., unisexual flowers, perigynia) clearly indicated it was a natural group, it obscured its relationships to all other Cyperaceae because the morphological gap between it and the rest of the family was so wide. Consequently, no plausible sister group to Carex has ever been proposed. Early molecular analyses narrowed the problem by placing Carex within a strongly-supported clade with the enigmatic monospecific genus Khaosokia, and tribes Dulichieae and Scirpeae (hereafter CDS), a group consisting of 2,250 species, or approximately 41% of all Cyperaceae. However, poor taxonomic sampling and the limited number of molecular markers used in these studies meant that the sister group to Carex remained a mystery. The goals of this thesis were to resolve evolutionary relationships within the CDS clade, to identify the sister group to Carex, and to develop a new natural tribal classification of CDS that could be used in future biogeographic and comparative analyses of Carex and its relatives. Initial phylogenetic analyses using two plastid markers (matK, ndhF) identified seven major CDS lineages, and suggested that Carex could be nested within a paraphyletic Scirpeae. However, backbone support for these relationships was low due to an ancient rapid radiation (~10 million years) followed by long divergence of the seven major lineages (~40 million years). The addition of conventional sequence-based markers from the plastid genome (rps16) and nuclear ribosomal region (ETS-1f, ITS) indicated that a traditional molecular approach would not resolve these key backbone nodes. Consequently, a recently developed flowering-plant-specific anchored enrichment probe kit targeting hundreds of conserved nuclear genes combined with next generation sequencing was used to resolve the CDS backbone. Although the resulting phylogenomic dataset was able to resolve the CDS backbone with high support, the topology and branch lengths only reaffirmed the isolated position of Carex. However, comparative morphological analyses of specimens at key herbaria not only suggested that Sumatroscirpus, a rare genus thought to be endemic to Sumatra, could be sister to Carex, but they also provided an easily accessible site to collect DNA in Northern Vietnam. Subsequent phylogenetic analyses of plastid (matK, ndhF, rps16) and nuclear ribosomal (ETS-1f, ITS) markers strongly supported Sumatroscirpus as the sister to Carex, and molecular dating estimates suggested they shared a common ancestor in the late Eocene (~36 million years ago). Comparative studies and ancestral state estimates of key morphological characters were congruent with this hypothesis, suggesting that the perigynium is not unique to Carex, but in fact a synapomorphy shared with Sumatroscirpus. This means that the initial key innovation in the remarkable diversification of Carex is not the perigynium, but could be the release of mechanical constraints that permitted the evolution of the remarkable morphological diversity of Carex perigynia seen today. A taxonomic revision of Sumatroscirpus revealed that this purportedly monospecific genus actually consisted of four species, and it extended its range over 2,400 km to the north into Northern Vietnam, Myanmar, and Southwestern China. The phylogenetic framework provided by the previous studies enabled a new tribal and generic classification of CDS to be proposed. Seven monophyletic tribes are recognised including four new tribes (Calliscirpeae, Khaosokieae, Sumatroscirpeae, Trichophoreae), and a new genus (Rhodoscirpus). Morphological synapomorphies are identified for all recognized tribes, and a worldwide treatment, including identification keys, is provided for Sumatroscirpus species, CDS genera, and Cyperaceae tribes.

Orientador: Luiza Sumiko Kinoshita / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-16T18:07:16Z (GMT). No. of bitstreams: 1 Silveira_MarcelaFirensda_M.pdf: 58417496 bytes, checksum: 9d9e08bd5e554b32666b89c7260c0f51 (MD5) Previous issue date: 2010 / Resumo: Rubiaceae Juss. é uma das maiores famílias de angiospermas, e também uma das famílias mais importantes da flora brasileira. A atual circunscrição da família compreende três subfamílias, entre elas, Rubioideae Verdc. O Parque Nacional da Serra da Canastra (PNSC) é a segunda maior Unidade de Conservação de Minas Gerais, compreendendo ambientes como campo, cerrado s.s. e floresta. O objetivo deste trabalho foi realizar o levantamento das espécies de Rubiaceae subfamília Rubioideae no PNSC e entorno, a fim de documentar a riqueza do grupo nesta região e contribuir para a taxonomia da família. Para tanto, foram realizadas coletas bimestrais, entre setembro de 2008 e novembro de 2009, e estudadas coleções de plantas herborizadas da região. O levantamento florístico da subfamília Rubioideae no PNSC resultou em um total de 57 espécies, pertencentes a 17 gêneros, ao longo de todas as principais formações vegetacionais. Psychotria L. foi o gênero mais rico, compreendendo 15 espécies: P. anceps Kunth; P. capitata Ruiz & Pav.; P. carthagenensis Jacq.; P. deflexa DC.; P. gracilenta DC.; P. hastisepala Müll.Arg.; P. hoffmannseggiana (Willd. ex Roem. & Schult.) Müll. Arg.; P. leiocarpa Cham. & Schltdl.; P. myriantha Müll.Arg.; P. nemorosa Gardner; P. prunifolia (Kunth) Steyerm.; P. stachyoides Benth.; P. subtriflora Müll.Arg.; P. trichophora Mull.Arg.; e P. vellosiana Benth. Borreria G.F.W.Mey. e Coccocypselum P.Browne foram representados por 8 e 7 espécies, respectivamente: B. capitata (Ruiz & Pav.) DC.; B. flavovirens Bacigalupo & E.L.Cabral; B. latifolia (Aubl.) K.Schum.; B. multiflora (DC.) Bacigalupo & E.L.Cabral; B. poaya (A.St.-Hil.) DC.; B. tenera DC.; B. verticillata (L.) G.Mey.; B. warmingii K. Schum.; C. aureum (Spreng.) Cham. & Schltdl.; C. capitatum (Graham) C.B. Costa & Mamede; C. condalia Pers.; C. cordifolium Nees & Mart.; C. hasslerianum Chodat; C. lanceolatum (Ruiz & Pav.) Pers.; e C. lymansmithii Standl. Declieuxia Kunth apresentou cinco espécies no PNSC: D. cordigera Mart. & Zucc. Ex Schult. & Schult.f.; D. deltoidea Mull.Arg.; D. fruticosa (Will. ex Roem. & Schult.) Kuntze; e D. lysimachioides Zucc. ex Schult. & Schult.f.; e D. oenanthoides Mart. & Zucc. ex Schult. & Schult. Os 13 gêneros restantes foram representados por uma a quatro espécies: Coussarea hydrangeifolia (Benth.) Müll.Arg.; Diodella apiculata (Roem. & Schult.) Delprete; D. teres (Walt.) Small; Emmeorhiza umbellate (Spreng.) K. Schum.; Faramea montevidensis (Cham. & Schltdl.) DC.; F. multiflora A. Rich. ex DC.; Galianthe angustifolia (Cham. & Schltdl.) E.L.Cabral; G. brasiliensis (Spreng.) E.L.Cabral & Bacigalupo; G. grandifolia E.L.Cabral; G. liliifolia (Standl.) E.L.Cabral; Geophila repens (L.) I.M. Johnst.; Manettia cordifolia Mart.; M. luteorubra (Vell.) Benth.; Margaritopsis cephalantha (Müll. Arg.) C.M. Taylor; Mitracarpus villosus (Sw.) DC.; Palicourea macrobotrys (Ruiz & Pav.) DC.; P. marcgravii A.St.-Hil.; P. rigida Kunth; Richardia brasiliensis B.A.Gomes; Rudgea sessilis (Vell.) Mull.Arg.; R. viburnoides (Cham.) Benth.; e Staelia lanigera (DC.) K. Schum. São apresentadas chaves de identificação para gêneros e espécies, descrições, fotos, ilustrações, distribuição geográfica e comentários / Abstract: Rubiaceae Juss. is one of the largest family of angiosperms, and it is one of the most important families of the Brazilian flora. The current familial circumscription comprises three subfamilies, Rubioideae Verdcourt among them. The Serra da Canastra National Park (SCNP) is the second larger protected area of the Minas Gerais State, and it includes numerous environments, like fields, savannas and forests. The objective of this study was to survey the species of Rubiaceae subfamily Rubioideae from SCNP and neighborhoods, and therefore, contribute to the taxonomy of this group. For this aim, periodic expeditions to the SCNP were carried out, between September 2008 and November 2009, and important collections of dried plants were studied. The survey of Rubioideae from SCNP reached 17 genera and 57 species, from several environments. Psychotria L. was the richest genus, comprising 15 species: P. anceps Kunth; P. capitata Ruiz & Pav.; P. carthagenensis Jacq.; P. deflexa DC.; P. gracilenta DC.; P. hastisepala Müll.Arg.; P. hoffmannseggiana (Willd. ex Roem. & Schult.) Müll. Arg.; P. leiocarpa Cham. & Schltdl; P. myriantha Müll.Arg.; P. nemorosa Gardner; P. prunifolia (Kunth) Steyerm.; P. stachyoides Benth; P. subtriflora Müll.Arg.; P. trichophora Mull.Arg.; and P. vellosiana Benth. Borreria G.F.W.Mey. and Coccocypselum P.Browne were represented by 8 and 7 species, respectively: B. capitata (Ruiz & Pav.) DC.; B. flavovirens Bacigalupo & E.L.Cabral; B. latifolia (Aubl.) K.Schum.; B. multiflora (DC.) Bacigalupo & E.L.Cabral; B. poaya (A.St.-Hil.) DC.; B. tenera DC.; B. verticillata (L.) G.Mey.; B. warmingii K. Schum.; C. aureum (Spreng.) Cham. & Schltdl.; C. capitatum (Graham) C.B. Costa & Mamede; C. condalia Pers.; C. cordifolium Nees & Mart.; C. hasslerianum Chodat; C. lanceolatum (Ruiz & Pav.) Pers.; and C. lymansmithii Standl. Declieuxia Kunth comprised five species in the SCNP: D. cordigera Mart. & Zucc. Ex Schult. & Schult.f.; D. deltoidea Mull.Arg.; D. fruticosa (Will. ex Roem. & Schult.) Kuntze; and D. lysimachioides Zucc. ex Schult. & Schult.f.; and D. oenanthoides Mart. & Zucc. ex Schult. & Schult. The 13 remaining genera were represented by only one to four species: Coussarea hydrangeifolia (Benth.) Müll.Arg.; Diodella apiculata (Roem. & Schult.) Delprete; D. teres (Walt.) Small; Emmeorhiza umbellate (Spreng.) K. Schum.; Faramea montevidensis (Cham. & Schltdl.) DC.; F. multiflora A. Rich. ex DC.; Galianthe angustifolia (Cham. & Schltdl.) E.L.Cabral; G. brasiliensis (Spreng.) E.L.Cabral & Bacigalupo; G. grandifolia E.L.Cabral; G. liliifolia (Standl.) E.L.Cabral; Geophila repens (L.) I.M. Johnst.; Manettia cordifolia Mart.; M. luteorubra (Vell.) Benth.; Margaritopsis cephalantha (Müll. Arg.) C.M. Taylor; Mitracarpus villosus (Sw.) DC.; Palicourea macrobotrys (Ruiz & Pav.) DC.; P. marcgravii A.St.-Hil.; P. rigida Kunth; Richardia brasiliensis B.A.Gomes; Rudgea sessilis (Vell.) Müll.Arg.; R. viburnoides (Cham.) Benth.; and Staelia lanigera (DC.) K. Schum. Keys of the genera and species, descriptions, pictures, illustrations, and comments about species and distribution are also provided / Mestrado / Biologia Vegetal / Mestre em Biologia Vegetal

The response of yarrow (Achillea millefolium L.) seedlings to reduced light, interference from barley (Hordeum vulgare) and some aspects of regeneration from rhizomes were the subject of investigations from 1976 until 1980. Seedlings grown under four intensities of photosynthetically active radiation (100, 46.8, 23.7 and 6.4% of full summer daylight) were harvested on six occasions and the changes with time in the logarithms of leaf area, leaf, stem, root and total dry weights per plant were described by polynomial regression equations. Relative growth (RGR), net assimilation rate (NAR), leaf area ratio (LAR), specific leaf area (SLA) and leaf weight ratio (LWR) were derived directly from the growth curves. SLA and LWR increased with increased shading causing LAR to rise, while NAR declined. Response curves of RGR on light intensity, derived from linear regressions of LAR and NAR on the logarithm of relative light intensity predicted maximum RGR to occur at light intensities which decreased with time. This was a consequence of ontogenetic changes in LAR, and changes in NAR apparently related to self shading. Linear regressions of LAR and NAR at a constant total plant dry weight of 1.62 g showed that the increase in LAR almost completely compensated for the reduction in NAR down to approximately 40% full daylight, and maximum RGR was predicted to occur at 59% full daylight. The light compensation point was estimated to be 3.6% full daylight. Yarrow populations established from 25 and 50 10 cm rhizome fragments m⁻² were grown alone and with barley at 194 or 359 plants m⁻². The barley populations were also grown alone. Growth analysis employing the regression technique showed the RGR of yarrow was reduced by barley from before jointing (Feekes Scale, Stage 6) as a consequence of reduced NAR. The NAR of yarrow was significantly reduced in the continued presence of barely, which by the time of the final barely harvest resulted in 91 and 94% reduction in the accumulated yarrow dry matter at 194 and 359 barely plants m⁻² respectively. The proportion of total dry matter allocated to seed and rhizome was also reduced by barley but the barley was unaffected by the yarrow. During the autumn and early winter, after removal of the barley, the suppressed yarrow had a higher RGR than the unsuppressed population, owing to higher LAR and NAR. Rhizome growth was vigorous during both autumn and winter in all yarrow populations, but the RGR of rhizome dry matter was higher in the suppressed yarrow during the autumn. This resulted in a progressive reduction in the difference in rhizome dry matter between suppressed and unsuppressed populations. Several aspects of the development and regenerative potential of rhizomes were investigated. In the first experiment, plants were established from seed and rhizome fragments and harvested on several occasions. Plants from both propagules formed rhizomes on which approximately 97% of auxiliary buds remained dormant, as long as the plants were undisturbed. Buds on rhizomes attached to the parent plant formed rhizome branches when the apex was damaged, had emerged from the soil, or in situations where internodes were congested. In the second experiment, rhizome fragments of 4, 8 and 16 cm in length were planted in soil at depths of 0, 2.5, 5.0, 10.0, 20.0 and 30.0 cm. All fragments on the soil surface died without forming shoots owing to desiccation whilst 100% mortality at 20 and 30 cm was probably the result of flooding. Within the 2.5 to 10.0 cm range, an increasing percentage of fragments survived (produced an aerial shoot(s)) as burial depth was reduced and fragment length increased. Within this depth range, the percentage of buds which had become active on undecayed fragments declined with increased length and burial depth. In the third experiment, single-node rhizome pieces were excised from rhizomes retrieved from field populations over a one year period, and incubated at 25°C for 10 days in darkness. More than 90% of buds formed vertical shoots throughout the year, indicating there was no period of innate dormancy in isolated buds. The effect of time of planting on the pattern of early regenerative development was assessed in the fourth experiment, in which 10 cm rhizome fragments were planted at 5 cm depth in soil on two occasions (in November and April). The developmental pattern was the same regardless of month of planting and new rhizomes were initiated at nodes on the vertical subterranean shoots when 5 to 6 aerial leaves had developed. The planted rhizome fragments declined in dry weight and a minimum weight occurred at about the time when rhizome initiation began.