Late-Quaternary Migrational Strategies of Tree Species

1987 ◽  
pp. 292-330
Author(s):  
Paul A. Delcourt ◽  
Hazel R. Delcourt
Keyword(s):  
Tree Species ◽  
Late Quaternary

Impact of sedimentary processes on white-sand vegetation in an Amazonian megafan

2016 ◽  
Vol 32 (6) ◽  
pp. 498-509 ◽  
Author(s):  
Carlos L. O. Cordeiro ◽  
Dilce F. Rossetti ◽  
Rogério Gribel ◽  
Hanna Tuomisto ◽  
Hiran Zani ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Tree Species ◽  
Late Quaternary ◽  
Remote Sensing Data ◽  
Canopy Height ◽  
Group Method ◽  
White Sand ◽  
Diameter At Breast Height ◽  
Tree Distribution ◽  
Breast Height

Abstract:Amazonian white-sand vegetation has unique tree communities tolerant to nutrient-poor soils of interest for interpreting processes of adaptation in neotropical forests. Part of this phytophysionomy is confined to Late Quaternary megafan palaeo-landforms, thus we posit that sedimentary disturbance is the main ecological factor controlling tree distribution and structuring in this environment. In this study, we characterize the topographic trend of one megafan palaeo-landform using a digital elevation model and verify its relationship to the forest by modelling the canopy height with remote sensing data. We also compare the composition and structure (i.e. canopy height and diameter at breast height) of tree groups from the outer and inner megafan environments based on the integration of remote sensing and floristic data. The latter consist of field inventories of trees ≥ 10 cm dbh using six (500 × 20 m) plots in várzea, terra firme and igapó from the outer megafan and 20 (50 × 20 m) plots in woodlands and forests from the inner megafan. The unweighted pair group method with arithmetic mean (UPGMA) and the non-metric multidimensional scaling (NMDS) were applied for clustering and dissimilarity analyses, respectively. The megafan is a sand-dominated triangular wetland with a topographic gradient of < 15 cm km−1, being more elevated along its axis. The outer megafan has a higher number of tree species (367), taller canopy height (mean of 14.1 m) and higher diameter at breast height (mean of 18.2 cm) than the white-sand forest. The latter records 89 tree species, mean canopy height of 8.4 cm and mean diameter at breast height of 15.3 cm. Trees increase in frequency closer to channels and toward the megafan's axis. The flooded and nutrient-poor sandy megafan substrate favoured the establishment of white-sand vegetation according to the overall megafan topography and morphological heterogeneities inherent to megafan sub-environments.

Late Quaternary Vegetation of Southern Isla Grande De Chiloé, Chile

1988 ◽  
Vol 29 (3) ◽  
pp. 294-306 ◽  
Author(s):  
Carolina Villagran
Keyword(s):  
Climatic Change ◽  
Pollen Analysis ◽  
Tree Species ◽  
Late Quaternary ◽  
Late Glacial ◽  
Pollen Diagrams ◽  
History Of ◽  
Valdivian Forest ◽  
Nothofagus Dombeyi ◽  
Pollen Records

Late-glacial-Holocene forest history of southern Isla Chiloé (latitude 43°10′ S) was reconstructed on the basis of pollen analysis in three profiles (Laguna Soledad, Laguna Chaiguata, Puerto Carmen). Prior to 12,500 yr B.P. pollen records are dominated by plant taxa characteristic of open habitats (Zone I). From 12,500 yr B.P. to the present, tree species predominate in the pollen records (Zones II–V). Between 12,500 and 9500 yr B.P. ombrophyllous taxa (Nothofagus, Podocarpus nubigena. Myrtaceae, Fitzroya/Pilgerodendron, and Drimys) are frequent in all pollen diagrams, suggesting a wetter and colder climate than the present. Between 9000 and 5500 yr B.P. Valdivian forest elements, such as Nothofagus dombeyi type, Weinmannia, and Eucryphia/Caldcluvia, dominate, indicating a period of drier and warmer climate. From 5500 yr B.P. onward, the expansion of mixed North Patagonian-Subantarctic forest elements and the increased frequence of Tepualia suggest increased rainfall and temperatures oscillating around the modern values.The change from open to forest vegetation (ca. 12,500 yr B.P.) probably represents the most pronounced climatic change in the record and can be interpreted as the glacial-postglacial transition in the study area.

Modelling of late Quaternary climate over Asia: a synthesis

Boreas ◽  
2004 ◽  
Vol 33 (2) ◽  
pp. 155-163 ◽  
Author(s):  
Andrew Bush
Keyword(s):  
Late Quaternary ◽  
Quaternary Climate

Purification of plasma membranes from leaves of conifer and deciduous tree species by phase partitioning and free-flow electrophoresis

1995 ◽  
Vol 95 (3) ◽  
pp. 399-408 ◽  
Author(s):  
Elena Toll ◽  
Federico J. Castillo ◽  
Pierre Crespi ◽  
Michele Crevecoeur ◽  
Hubert Greppin
Keyword(s):  
Tree Species ◽  
Plasma Membranes ◽  
Free Flow ◽  
Deciduous Tree ◽  
Phase Partitioning
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