scholarly journals Conifer wood assemblage dominated by Podocarpaceae, early Eocene of Laguna del Hunco, central Argentinean Patagonia

PhytoKeys ◽  
2020 ◽  
Vol 156 ◽  
pp. 81-102
Author(s):  
Roberto R. Pujana ◽  
Peter Wilf ◽  
Maria A. Gandolfo
Keyword(s):  
Growth Ring ◽  
Light Availability ◽  
Pollen Grains ◽  
Early Eocene ◽  
Single Specimen ◽  
Uniform Temperature ◽  
Mature Trees ◽  
Argentinean Patagonia ◽  
Extinct Group ◽  
Conifer Wood

During the early Eocene, Patagonia had highly diverse floras that are primarily known from compression and pollen fossils. Fossil wood studies from this epoch are scarce in the region and largely absent from the Laguna del Hunco flora, which has a highly diverse and excellently preserved compression assemblage. A collection of 26 conifer woods from the Laguna del Hunco fossil-lake beds (early Eocene, ca. 52 Ma) from central-western Patagonia was studied, of which 12 could be identified to genus. The dominant species is Phyllocladoxylon antarcticum, which has affinity with early-diverging Podocarpaceae such as Phyllocladus and Prumnnopitys. A single specimen of Protophyllocladoxylon francisiae probably represents an extinct group of Podocarpaceae. In addition, two taxonomic units of cf. Cupressinoxylon with putative affinity to Podocarpaceae were found. Diverse Podocarpaceae taxa consistent with the affinities of these woods were previously reported from vegetative and reproductive macrofossils as well as pollen grains from the same source unit. Some of the woods have galleries filled with frass. Distinct growth ring boundaries indicate seasonality, inferred to represent seasonal light availability. Growth ring widths suggest that the woods came from mature trees, whereas the widths and types of some rings denote near-uniform temperature and water availability conditions.

Ten-year postharvest effects of silviculture systems on soil-resource availability and conifer nutrition in a northern temperate forest

2004 ◽  
Vol 34 (4) ◽  
pp. 800-809 ◽  
Author(s):  
J M Kranabetter ◽  
K D Coates
Keyword(s):  
Tree Growth ◽  
Forest Floor ◽  
Light Availability ◽  
Tsuga Heterophylla ◽  
Picea Sitchensis ◽  
Western Hemlock ◽  
Thuja Plicata ◽  
Net N Mineralization ◽  
Mature Trees ◽  
Foliar N

Silviculture systems (clear-cut, partial-cut, and unharvested forest) were compared 9–10 years after harvesting to determine their effects on conifer nutrition and the availability of soil resources, especially nitrogen. These results were used to discuss the effects of silviculture systems on tree growth in relation to the more commonly described effects of light. Differences in soil properties across the silviculture treatments were most apparent in the forest floor. Depth and C/N ratio of the forest floor had decreased slightly in clearcuts, and forest-floor moisture was highest under partial-cut forest. Despite these differences in soil chemistry and soil moisture, no differences were detected in mineralizable N (anaerobic incubation) or in situ net N mineralization among treatments. Height growth and foliar mass were reduced under the low-light conditions of the partial-cut forest, but there were no differences in foliar N concentrations of hybrid white spruce (Picea glauca (Moench) Voss × Picea sitchensis (Bong.) Carrière), western redcedar (Thuja plicata Dougl. ex D. Don), or western hemlock (Tsuga heterophylla (Raf.) Sarg.) saplings. Mature western hemlock trees in partial-cut forest also had concentrations of foliar N equal to that of mature trees in the unharvested forest. Overall, we detected only minor effects of silviculture systems on soils after 10 years, and we conclude that light availability is likely more responsible for the current differences in tree growth.

Lignin Distribution During Latewood Formation in Pinus Radiata D. Don

IAWA Journal ◽  
1992 ◽  
Vol 13 (4) ◽  
pp. 381-387 ◽  
Author(s):  
L.A. Donaldson
Keyword(s):  
Pinus Radiata ◽  
Growth Ring ◽  
Middle Lamella ◽  
Interference Microscopy ◽  
Late Winter ◽  
Primary Wall ◽  
Single Specimen ◽  
Lignin Distribution ◽  
Transmission Electron ◽  
Ring Boundary

Lignin distribution during formation of latewood tracheids in Pinus radiata, was determined by quantitative interference microscopy, and by potassium permanganate staining combined with transmission electron microscopy. Lignin distribution varied among trees sampled on the same date in late winter. In one tree, latewood tracheids were fully lignified up to the growth ring boundary. However in most trees sampled, latewood was only partially lignified. The extent of lignification varied from tree to tree but in all cases, at least some lignin was present in the middle lamella and primary wall at the growth ring boundary. Latewood was ideal for examining the lignification process because of the large number of different stages present in a single specimen.

scholarly journals The aspiration of bordered pits in conifer wood

1972 ◽  
Vol 181 (1065) ◽  
pp. 395-406 ◽  
Keyword(s):  
Surface Tension ◽  
Hydrogen Bonding ◽  
Pinus Sylvestris ◽  
Growth Ring ◽  
Surface Tension Force ◽  
The Other ◽  
Liquid Meniscus ◽  
Pit Membrane ◽  
Bordered Pits ◽  
Conifer Wood

The variation of tension in a radial strand of a bordered pit membrane during drying has been derived theoretically from two approaches. One considers the mechanical extension of the strand, while the other considers the surface tension force caused by an annular liquid meniscus in the pit chamber. The tension has been calculated for pits in earlywood, in latewood and in regions near the earlywood-latewood boundary of a single growth ring in Pinus sylvestris L., using experimentally observed typical values for pit dimensions. The occurrence of aspiration of earlywood but not of latewood pits in air-seasoned wood is correctly predicted by the analysis, which also predicts that, contrary to accepted theory, earlywood pit membranes should be displaced and brought into contact with the pit border irrespective of the liquid present during drying. It is shown that this must involve considerable creep in the radial strands. Permanent aspiration must only occur when the liquid promotes bonding between the membrane and the border, and the probability that this is hydrogen bonding is discussed.

Ontogenetic changes in leaf phenology of a canopy species, Elateriospermum tapos (Euphorbiaceae), in a Malaysian rain forest

2002 ◽  
Vol 18 (1) ◽  
pp. 91-105 ◽  
Author(s):  
NORIYUKI OSADA ◽  
HIROSHI TAKEDA ◽  
AKIO FURUKAWA ◽  
MUHAMAD AWANG
Keyword(s):  
Rain Forest ◽  
Meteorological Factors ◽  
Light Availability ◽  
Leaf Phenology ◽  
Leaf Fall ◽  
Ontogenetic Changes ◽  
Mature Trees ◽  
Leaf Production ◽  
Leaf Emergence ◽  
Canopy Species

Leaf phenology was studied in individuals of a canopy species, Elateriospermum tapos (Euphorbiaceae), at various ontogenetic stages, in a Malaysian rain forest. The timing of leaf emergence was not synchronized among sapling individuals, and was not correlated with any meteorological factors of the preceding month. The timing of leaf fall in saplings was positively correlated with net radiation, and maximum and minimum temperature, but negatively correlated with relative humidity the preceding month, although these correlations were weak. The leaf production rate was larger under higher light, but the leaf fall rate was not related to the light regime of the saplings. Thus, leaf production was enhanced by the light availability for each individual, while leaf fall may have been enhanced by drought stress. Non-synchronous leaf production appears to be important for sapling growth, allowing saplings to occupy better-lit space quickly. On the other hand, tall trees showed a clear synchronous leaf-fall pattern, with an annual cycle, and no meteorological factors were correlated with the timing of leaf fall. Mature trees of this species produced flowers simultaneously with new leaves, after shedding their leaves. This suggests that the need to synchronize flowering might be the primary determinant of leaf production phenology in mature individuals.

A new genus and species of Euphaeidae (Odonata, Zygoptera) from the early Eocene Okanagan Highlands locality at Republic, Washington, U.S.A.

Zootaxa ◽  
2021 ◽  
Vol 4966 (3) ◽  
pp. 392-400
Author(s):  
S. BRUCE ARCHIBALD ◽  
ROBERT A. CANNINGS
Keyword(s):  
North America ◽  
New Genus ◽  
Early Eocene ◽  
Western North America ◽  
Single Specimen ◽  
New Genus And Species ◽  
Okanagan Highlands

We describe Republica weatbrooki, a new genus and species of damselfly (Odonata, Zygoptera, Euphaeidae, Eodichromatinae) from the early Eocene (Ypresian) fossil locality at Republic, Washington, U.S.A. Its single specimen is the sole damselfly known from the Okanagan Highlands series of localities in far-western North America. 

The micro- and megafossil record of Nothofagaceae from South America

2020 ◽  
Author(s):  
Roberto R Pujana ◽  
Damián A Fernández ◽  
Carolina Panti ◽  
Nicolás Caviglia
Keyword(s):  
South America ◽  
Fossil Record ◽  
Surface Sediments ◽  
Sedimentary Rocks ◽  
Pollen Grains ◽  
Early Eocene ◽  
Reproductive Structures ◽  
The Family ◽  
Fossil Records ◽  
Cretaceous Fossils

Abstract We compiled the numerous fossil records (486) assigned to Nothofagaceae including pollen grains (from surface sediments and continental and oceanic borehole cores), leaves, woods and reproductive structures from South America. All the records are revised and the latest systematic treatments and ages of the bearing strata of each record are followed. When possible, we proposed a subgeneric affinity to each record based on updated bibliography. Fossils of three (Nothofagus, Fuscospora and Lophozonia) of the four subgenera are found in similar proportions through time since the Late Cretaceous. Fossils with reliable affinity with subgenus Brassospora were not found in South America. Most of the records are concentrated in the southern tip of South America (Patagonia Region) and nearby areas. After a significant presence of Nothofagaceae in the Cretaceous, the family declined in diversity and abundance in the Palaeocene and then increased from the Eocene to the Miocene. In the Miocene, the records reach their maximum diversity and abundance, and Nothofagaceae usually dominate the assemblages of pollen, leaves and woods from Patagonia. Pliocene Nothofagaceae records are virtually absent, probably because sedimentary rocks of that age are rare in Patagonia. The fossil record for Nothofagaceae varies according to environmental turnover; when tropical/subtropical floras were present in Patagonia in the Palaeocene–early Eocene, Nothofagaceae contracted southwards and when open steppes developed in the Miocene of east Patagonia, Nothofagaceae contracted westward.

scholarly journals Pre-breeding in Passiflora subrotunda Mast.: Morphological and Reproductive Characterization at Different Light Levels

HortScience ◽  
2018 ◽  
Vol 53 (7) ◽  
pp. 949-957 ◽  
Author(s):  
Viviane de Oliveira Souza ◽  
Margarete Magalhães Souza ◽  
Alex-Alan Furtado de Almeida ◽  
Joedson Pinto Barroso ◽  
Alexandre Pio Viana ◽  
...  
Keyword(s):  
Ornamental Plants ◽  
Light Availability ◽  
Morphological Characteristics ◽  
Pollen Grains ◽  
Fertilization Rate ◽  
Breeding Programs ◽  
Light Levels ◽  
Self Compatibility ◽  
Qualitative Characters ◽  
Polar Area

Passiflora are ornamental plants that are appreciated as part of outdoor decor, composing pergolas and gardens, as well as in interior ornamentation where species tolerant to environments with less light availability are used. The objective of this study was to evaluate the influence of different levels of light and pot types on morphological and reproductive characteristics in Passiflora subrotunda and to support genetic breeding programs of ornamental passifloras. The conditions of 75% and 100% light favored vegetative morphological characteristics through the time (105 days). Floral characteristics also presented higher values along increasing light levels. All qualitative characters related to flower and plant coloration did not vary among genotypes. The species possesses diurnal anthesis and flowers throughout the year. Plants cultivated in concrete pots showed greater growth and flower production. Pollen grains (PGs) are large, with an isopolar form, a small polar area, and a long aperture, and amylaceous. Percentage of viable PG was high: above 97% using Alexander solution and reaching up to 91% with fluorescein diacetate. Stigmas were partially receptive during the flower’s opening period. Percentage of self-compatibility was lower, based on the higher fertilization rate through cross-pollination. These information will be used in planning of ornamental Passiflora-breeding programs, assisting in the selection of characteristics and breeding methods.

Fossil woods from the Eocene of Corcovado, Argentinean Patagonia: geological setting and conifer diversity

IAWA Journal ◽  
2021 ◽  
pp. 1-15
Author(s):  
Roberto R. Pujana ◽  
Inés Aramendía ◽  
Juan L. García Massini ◽  
Sol Noetinger
Keyword(s):  
Species Richness ◽  
Fossil Wood ◽  
Conifer Species ◽  
Stratigraphic Unit ◽  
Geological Setting ◽  
Argentinean Patagonia ◽  
Conifer Wood

Abstract Eocene paleofloras of Patagonia are diverse and increasingly known. A new assemblage of fossil wood has been recovered from Eocene sediments in Corcovado, western Argentinean Patagonia. The lithological succession (formerly Arroyo Lyn Formation sensu Pesce 1979) is correlated with the Huitrera Formation. The specimens were mostly found embedded in sandstones and conglomerates. One-third of the assemblage are conifers and studied herein. We found four taxonomic types: Agathoxylon cf. antarcticum (Araucariaceae), Phyllocladoxylon antarcticum (Podocarpaceae), Podocarpoxylon dusenii (Podocarpaceae), and Cupressinoxylon hallei (Cupressaceae or Podocarpaceae). The presence of four taxonomic units among only 7 specimens suggests a significant conifer species richness in the assemblage. Araucariaceae and dominant Podocarpaceae are usually found in previously described conifer wood assemblages from the Eocene of Patagonia andAntarctica. The diversity of the conifer assemblage in Corcovado is very similar to that found at Laguna del Hunco (these two localities are 170 km distant), also from the Huitrera Formation. This is consistent with the proposal that the bearing sediments of both localities are from the same stratigraphic unit.

Floral response to rapid warming in the earliest Eocene and implications for concurrent faunal change

Paleobiology ◽  
2001 ◽  
Vol 27 (3) ◽  
pp. 539-563 ◽  
Author(s):  
Scott L. Wing ◽  
Guy J. Harrington
Keyword(s):  
Pollen Grains ◽  
Early Eocene ◽  
Fossil Plants ◽  
Faunal Change ◽  
Late Paleocene ◽  
Mammalian Faunas ◽  
The Mean ◽  
The Difference ◽  
Willwood Formation ◽  
Biotic Change

During the first 10–20 Kyr of the Eocene temperatures warmed by 4–8°C in middle and high latitudes, then cooled again over the succeeding ∼200 Kyr. Major changes in the composition of marine and terrestrial faunas, including one of the largest mammalian turnover events of the Cenozoic, occurred during this temperature excursion. To better understand the effects of rapid climatic change on continental biotas, we studied 60 fossil pollen samples collected from 900 m of section spanning approximately three million years of the late Paleocene and early Eocene; the samples come from the Fort Union Formation and Willwood Formation in the Bighorn Basin of northwestern Wyoming, paleolatitude approximately 47°N. There are 40 samples from the 500 m of rock deposited during the one million year interval centered on the Paleocene/Eocene boundary, although pollen was not preserved well in rocks representing the short warm interval at the base of the Eocene.Overall, the palynoflora shows moderate change in composition and diversity. Two pollen taxa clearly expanded their ranges to include North America in the first 400 Kyr of the Eocene, Platycarya (Juglandaceae), and Intratriporopollenites instructus (cf. Tilia), but they account for less than 5% of pollen grains in the early Eocene. There are no last appearances of common taxa associated with the Paleocene/Eocene boundary. The most noticeable palynological changes are the decrease in abundance of Caryapollenites spp. and Polyatriopollenites vermontensis (Juglandaceae), and the increase in abundance of Taxodiaceae (bald cypress family), Ulmaceae (elm family), and Betulaceae (birch family), particularly Alnipollenites spp. (alder). There are 22% more species in the Eocene samples than in the Paleocene samples; mean richness of Eocene samples is 17% higher than the mean of Paleocene samples. The mean evenness of Eocene samples is higher than that of Paleocene samples, but the difference is not significant.The modest level of floral change during the late Paleocene and early Eocene contrasts with the major taxonomic turnover and ecological rearrangement of North American mammalian faunas observed at the same time. Faunal change probably resulted from intercontinental range expansion across Arctic land bridges that became habitable as a result of high-latitude warming, so it is surprising that climatically sensitive plants did not also experience a major episode of interchange. The absence of fossil plants from the temperature excursion interval itself could prevent us from recognizing a transient shift in floral composition, but it is clear that the flora did not undergo a major and permanent restructuring like that seen in the mammals. The contrast between the moderate floral response to warming and the strong faunal response is consistent with the idea that interactions between immigrant and native taxa, rather than climate directly, were the primary cause of terrestrial biotic change across the Paleocene/Eocene boundary.

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