Topic
Eucryphia
About: Eucryphia is a research topic. Over the lifetime, 25 publications have been published within this topic receiving 747 citations.
Papers
TL;DR: Results are consistent with the idea that accumulation of an extensive leaf area eventually gives juvenile shade-tolerant evergreens a net carbon gain advantage over their light-demanding associates in low light.
Abstract: Summary
1
Interspecific variation in leaf life span of woody plants should have important consequences for ontogenetic variation in biomass distribution, and hence carbon balance, in low light. This proposal was examined by measuring foliage turnover, growth, biomass allocation and biomass distribution of juveniles (25–1180 mm tall) of four evergreens differing in shade tolerance, growing in low light (2–5% canopy openness) in temperate rainforest understoreys in south-central Chile.
2
As predicted, ontogenetic trends in leaf area ratio (LAR) of two very shade-tolerant species with long-lived leaves (Aextoxicon punctatum and Myrceugenia planipes) contrasted strongly with those of mid-tolerant Eucryphia cordifolia and intolerant Aristotelia chilensis. Low-light LAR fell rapidly with increasing plant size in Eucryphia and Aristotelia, but was size-invariant in the two shade-tolerant taxa. As a result, although small seedlings of Eucryphia and Aristotelia displayed more leaf area than shade-tolerant seedlings of similar size (largely because of differences in specific leaf area), this relationship was reversed for plants over ≈500 mm tall.
3
Although the slower foliage turnover of the shade-tolerant species at least partly explains this reversal, allocational differences may also be involved. Root mass fraction of both shade-tolerant species was significantly negatively correlated with size, possibly reflecting declining allocation to roots in larger plants. In contrast, root mass fraction was not correlated with size in Eucryphia or Aristotelia.
4
Above-ground relative growth rate in low light followed similar ontogenetic trends to LAR, declining more quickly in light-demanding species than in shade-tolerant associates. As a result, large seedlings (>400 mm tall) of shade-tolerant Myrceugenia and Aextoxicon grew more quickly than their light-demanding associates at the same height. The steeply declining LAR and growth of Eucryphia and Aristotelia suggest that these taxa will eventually die of energy starvation in low light.
5
Results are consistent with the idea that accumulation of an extensive leaf area eventually gives juvenile shade-tolerant evergreens a net carbon gain advantage over their light-demanding associates in low light. Awareness of long-term ontogenetic trends will enhance understanding of relationships of shade-tolerance variation with morphology and growth of woody evergreens.
150 citations
TL;DR: A model based on the extant cool temperate Valdivian rainforests is proposed and ecological reconstructions based on palaeobotanical and geological evidence suggest that changes in the palaeovegetation reflect natural dynamics following volcanic disturbances.
99 citations
1 Jan 2003
TL;DR: In this article, the authors used data from fossil macrofloras and microfloras in southeastern Australia are used to reconstruct vegetation and climates for the early Paleogene, showing that for much of the late Paleocene to middle Eocene, complex, species-rich forests were predominant in the southeastern Australia, under mesothermal humid climates.
Abstract: In this study, data from fossil macrofloras and microfloras in southeastern Australia are used to reconstruct vegetation and climates for the early Paleogene. Our data show that for much of the late Paleocene to middle Eocene, complex, species-rich forests were predominant in southeastern Australia, under mesothermal humid climates (mean annual temperature 16-22 °C, coldest quarter mean temperature >10 °C, mean annual precipitation >150 cm/yr). A minor cooling episode may have occurred in the mid-early Eocene. Megathermal climates may have been present in lowlands in the latest early Eocene, during the Cenozoic Global Climatic Optimum. These forests were dominated by taxa characteristic of present-day mesothermal-megathermal high-rainfall multistratal forests; e.g., Cunoniaceae, Elaeocarpaceae, Gymnostoma (Casuarinaceae), Lauraceae (e.g., Beilschmiedia, Cryptocarya and Endiandra), and Proteaceae. A prominent treefern element (Cyathea and Dicksonia types) was present in the early Eocene. A number of megathermal taxa, including Cupanieae (Sapindaceae) and Ilex (Aquifoliaceae), were present through the early and middle Eocene. Taxa characteristic of modern-day microthermal to mesothermal forests were also present, e.g., Nothofagus (Nothofagaceae), Eucryphia (Eucryphiaceae), Libocedrus (Cupressaceae) and Podocarpaceae (Acmopyle and Dacrycarpus). The relictual araucarian conifer, Wollemia, and other Araucariaceae were present through the late Paleocene to early Eocene. There is limited physiognomic evidence to suggest the late Paleocene to early Eocene forests contained some deciduous canopy trees.
99 citations
TL;DR: Parsimony cladistic analyses of chloroplast DNA sequences from two loci, trnL-trnF and rbcL, and morphology show that three genera often placed in their own families, Bauera, Davidsonia, and Eucryphia, are nested within Cunoniaceae, a circumscription of the flowering plant family with 26 genera and approximately 300 species.
Abstract: A phylogeny and revised classification of the flowering plant family Cunoniaceae and related taxa is presented. Parsimony cladistic analyses, including bootstrap and decay analyses, of chloroplast DNA sequences from two loci, trnL-trnF and rbcL, and morphology show that three genera often placed in their own families, Bauera, Davidsonia, and Eucryphia, are nested within Cunoniaceae. Brunellia may be most closely related to the Australian pitcher plant Cephalotus, and Aphanopetalum is in Saxifragales. Within Cunoniaceae, the New Guinean-South Pacific genera Acsmithia and Spiraeanthemum form a sister clade to the rest of family. Within this larger clade is a basal grade in which flowers mature centrifugally on an inflorescence axis, and a clade in which flowers mature synchronously to acropetally on an inflorescence axis. Other conspicuous morphological characters, including stipule position, inflorescence form, petal presence or absence, number of pollen colpi, carpel number, and fruit morphology,...
97 citations
TL;DR: The latitudinal trend in defence did not support the prediction based on the resource availability hypothesis and may indicate that herbivore pressure is providing an overriding selection pressure, although there are alternative explanations.
Abstract: Tropical plants have been suggested to have higher levels of mechanical, chemical and biotic defences than temperate plants. However, comparisons have usually included deciduous species within the temperate group, which confounds the analysis since deciduous species are predicted to have a different strategy with respect to investment, nutrition and defence than evergreen species. In this study we examined levels of defence and nutrition in five evergreen species of Eucryphia occurring along a latitudinal gradient in eastern Australia, grown under common conditions in a glasshouse. From the resource-availability hypothesis we predicted the opposite gradient in defence investment, i.e. that lowest levels of defence will occur in tropical species with potentially high growth rates and annual productivity. However, we found an increase in cell wall content, total phenolics and tannin activity, and a decrease in protein availability, with decreasing latitude and/or increasing mean annual temperature. Hence, there was a trend of increasing defence (although not in leaf toughness) and declining nutritional quality towards the tropics. These latitudinal trends were recorded in both mature and expanding leaves. The same trends were observed in leaves of two species collected from the field, indicating that the results were not peculiar to the experimental growth regime. The latitudinal trend in defence did not support our prediction based on the resource availability hypothesis and may indicate that herbivore pressure is providing an overriding selection pressure, although there are alternative explanations.
44 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2020 | 1 |
| 2018 | 1 |
| 2009 | 1 |
| 2007 | 1 |
| 2006 | 2 |
| 2004 | 2 |