Phytolith variability in Zingiberales: A tool for the reconstruction of past tropical vegetation

2013 ◽  
Vol 370 ◽  
pp. 1-12 ◽  
Author(s):  
Stephanie T. Chen ◽  
Selena Y. Smith
Keyword(s):  
Tropical Vegetation

SPOT4 potential for the monitoring of tropical vegetation. A case study in Sumatra

1999 ◽  
Vol 20 (14) ◽  
pp. 2761-2785 ◽  
Author(s):  
V. Trichon ◽  
D. Ducrot ◽  
J. P. Gastellu-Etchegorry
Keyword(s):  
Tropical Vegetation

Dry-season climate drives interannual variability in tropical tree growth

2021 ◽  
Author(s):  
Pieter Zuidema ◽  
Flurin Babst ◽  
Peter Groenendijk ◽  
Valerie Trouet
Keyword(s):  
Tree Ring ◽  
Tree Growth ◽  
Woody Biomass ◽  
Dry Season ◽  
Tropical Tree ◽  
Biomass Growth ◽  
Wet Season ◽  
Tropical Vegetation ◽  
Tropical Tree Growth ◽  
Climate Responses

<p>Tropical and subtropical ecosystems are primarily responsible for the large inter-annual variability (IAV) in the global carbon land sink. The response of tropical vegetation productivity to climatic variation likely drives this IAV, but the climate sensitivity of key productivity components are poorly understood. Tree-ring analysis can help fill this knowledge gap by estimating IAV in woody biomass growth, the major carbon accumulation process in tropical vegetation.</p><p> </p><p>Here, we evaluate the climate responses of woody biomass growth throughout the global tropics. Using an unprecedented compilation of tropical tree-ring data, we test hypotheses that (1) precipitation (P) and maximum temperature (T<sub>max</sub>) have opposite and additive effects on annual tree growth, (2) these climate responses amplify with increasing aridity and (3) wet-season climate is a more important driver of growth than dry-season climate.</p><p> </p><p>We established a network of 347 tree-ring width chronologies compiled from (sub-)tropical latitudes, representing 99 tree species on five continents and obtained from contributors (n=112) and the International Tree-Ring Data Bank (ITRDB; n=235). Our network is climatologically representative for 66% of the pantropical land area with woody vegetation.</p><p> </p><p>To test hypotheses we re-developed standardized ring-width index (RWI) chronologies and assessed climate responses using SOM cluster analysis (monthly P and T<sub>max</sub>) and multiple regression analysis (seasonal P and T<sub>max</sub>). Our results were consistent with hypothesis 1: effects of monthly or seasonal P and T<sub>max</sub> on tree growth were indeed additive and opposite, suggesting water availability to be the primary driver of tropical tree growth. In accordance with hypothesis 2, these climate responses were stronger at sites with lower mean annual precipitation or a larger annual water deficit. However, our results contrast those expected under hypothesis 3. Three of the four clusters show a dominant role of dry-season climate on annual tree growth and regression analyses confirmed this strong dry-season role.</p><p> </p><p>The strong dry-season effect on tropical tree growth seemingly contrasts the general notion that tropical vegetation productivity peaks during the wet season but is consistent with studies showing that climatologically benign dry seasons increase reserve storage and xylem growth. We posit that dry-season climate constrains the magnitude of woody biomass growth that takes place during the following wet season, and thus contributes to IAV in tree growth.</p><p> </p><p>By providing field-based insights on climate sensitivity of tropical vegetation productivity, our study contributes to the major task in Earth system science of quantifying, understanding, and predicting the IAV of the carbon land sink.</p>

scholarly journals Seedling Community in a Patchy Tropical Vegetation Under the Influence of Bamboos

2018 ◽  
Vol 11 ◽  
pp. 194008291876712 ◽  
Author(s):  
Débora C. Rother ◽  
Eric Gorgens ◽  
Natalia Guerin ◽  
Ricardo R. Rodrigues ◽  
Marco A. Pizo
Keyword(s):  
Tropical Vegetation ◽  
Seedling Community

scholarly journals Common Birds of Chitwan National Park, Nepal

2017 ◽  
Vol 1 (2) ◽  
pp. 19-26
Author(s):  
Parveen Kumar Jha
Keyword(s):  
Protected Area ◽  
National Park ◽  
Bird Species ◽  
Point Of View ◽  
Central Nepal ◽  
South Central ◽  
Tropical Vegetation ◽  
Chitwan National Park ◽  
Common Birds ◽  
Very High

 This research paper gives checklist of common birds of Chitwan National Park, which is a wild-life protected area in south-central Nepal. It covers tropical and sub-tropical vegetation. It is first protected area and includes 932 sq. km. Common birds observed are about 170 belonging to 48 Avian families during 2013-2014. Present investigator has very minutely observed birds in habitat conditions. Bird species were recognized by very high binocular. Birds were thoroughly studied from point of view of Taxonomy. Machans were also erected for observing birds.

A propos de la theorie bio-rhexistasique

1956 ◽  
Vol S6-VI (4-5) ◽  
pp. 451-452
Author(s):  
Henri Termier ◽  
G. Termier
Keyword(s):  
The Other ◽  
Lake Basin ◽  
Tropical Vegetation ◽  
Other Hand

Abstract The formation of siliceous crusts, such as that of the Eyre lake basin in Australia, and other examples of silicification can probably be explained by the bio-rhexistasy theory. On the other hand, tropical vegetation and weathering do not seem to affect the sedimentary regime off the coast of Indonesia, as would be expected according to the theory. It is concluded that the theory is valid for stable areas, but that the nature and regime of sedimentation in unstable areas are largely a function of orogenic and probably also epeirogenic activity.

Intimations on the Tertiary vegetation of southern Africa

Bothalia ◽  
1983 ◽  
Vol 14 (3/4) ◽  
pp. 345-354 ◽  
Author(s):  
J. A. Coetzee
Keyword(s):  
Southern Africa ◽  
Major Change ◽  
Pollen Record ◽  
Vegetation Shifts ◽  
Ice Cap ◽  
Tropical Vegetation ◽  
Cape Peninsula ◽  
Benguela Current ◽  
And Migration ◽  
The Antarctic

Fossil pollen sequences from the Cape Peninsula and the Saldanha region indicate that sub tropical vegetation and climates existed in these regions during the Miocene. The pollen record from the Cape Peninsula may point to the extinction of some taxa by the terminal Miocene/Early Pliocene with the subsequent strong development of macchia. This major change can probably be related to the maximum build-up of the Antarctic ice-cap in the latest Miocene and the accompanying profound palaeoceanographic changes such as the major cooling of the Benguela current with its effect on the aridification of the Namib desert, and the global glacio-eustatic sea level drop.Parallel palynological and lithological studies in the Saldanha region show that prominent Miocene vegetation shifts were linked to profound local changes in the palaeoenvironment associated with the northward migration of the Miocene Berg River. Such studies are of paramount importance for the possible assessment of the causes of changes in the palaeoenvironment and should first be carried out at many more sites over a wide region. It is to some extent premature to draw firm conclusions as to the origin and migration of some taxa in southern Africa. The record of very primitive angiosperms such as the ClavatipolleniteslAscarina complex and Winteraceae is of considerable phytogeographic interest.

scholarly journals Tropical land carbon cycle responses to 2015/16 El Niño as recorded by atmospheric greenhouse gas and remote sensing data

2018 ◽  
Vol 373 (1760) ◽  
pp. 20170302 ◽  
Author(s):  
Emanuel Gloor ◽  
Chris Wilson ◽  
Martyn P. Chipperfield ◽  
Frederic Chevallier ◽  
Wolfgang Buermann ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
East Asia ◽  
El Niño ◽  
Carbon Flux ◽  
El Nino ◽  
Minor Amount ◽  
Tropical Africa ◽  
Tropical Vegetation ◽  
Carbon Release ◽  
The Impact

The outstanding tropical land climate characteristic over the past decades is rapid warming, with no significant large-scale precipitation trends. This warming is expected to continue but the effects on tropical vegetation are unknown. El Niño-related heat peaks may provide a test bed for a future hotter world. Here we analyse tropical land carbon cycle responses to the 2015/16 El Niño heat and drought anomalies using an atmospheric transport inversion. Based on the global atmospheric CO 2 and fossil fuel emission records, we find no obvious signs of anomalously large carbon release compared with earlier El Niño events, suggesting resilience of tropical vegetation. We find roughly equal net carbon release anomalies from Amazonia and tropical Africa, approximately 0.5 PgC each, and smaller carbon release anomalies from tropical East Asia and southern Africa. Atmospheric CO anomalies reveal substantial fire carbon release from tropical East Asia peaking in October 2015 while fires contribute only a minor amount to the Amazonian carbon flux anomaly. Anomalously large Amazonian carbon flux release is consistent with downregulation of primary productivity during peak negative near-surface water anomaly (October 2015 to March 2016) as diagnosed by solar-induced fluorescence. Finally, we find an unexpected anomalous positive flux to the atmosphere from tropical Africa early in 2016, coincident with substantial CO release. This article is part of a discussion meeting issue ‘The impact of the 2015/2016 El Niño on the terrestrial tropical carbon cycle: patterns, mechanisms and implications’.

1. General Remarks on the Coal Formation of the Great Valley of the Scottish Lowlands

1845 ◽  
Vol 1 ◽  
pp. 74-77
Author(s):  
Greenock
Keyword(s):  
Sufficient Evidence ◽  
Dry Land ◽  
Tropical Vegetation ◽  
Coal Measures ◽  
Great Valley

In this paper the author stated, that although there is sufficient evidence in the mechanical origin and organic contents of the beds (some of them of extraordinary thickness and extent), which form the coal-measures, to prove the pre-existence of much larger tracts of dry land, in connection with each other, than could possibly have been afforded by the older portions of the present countries; such proofs are altogether wanting when we endeavour to restore, in imagination, what might have been the probable extent of that land, the greater part of which may now lie buried beneath the ocean, or have since been covered by more recent deposits. It appears, however, to have been clothed with a luxuriant tropical vegetation, and sufficiently elevated to have given rise to the rivers and torrents, by which the materials for composing the coal strata had been carried down into the lakes or estuaries, where to all appearance they were deposited.

scholarly journals Chlorophyll fluorescence varies more across seasons than leaf water potential in drought-prone plants

2016 ◽  
Vol 88 (suppl 1) ◽  
pp. 549-563 ◽  
Author(s):  
BRUNO H.P. ROSADO ◽  
EDUARDO A. DE MATTOS
Keyword(s):  
Chlorophyll Fluorescence ◽  
Water Potential ◽  
Leaf Water Potential ◽  
Water Availability ◽  
Leaf Water ◽  
Tropical Species ◽  
Tropical Plants ◽  
Tropical Vegetation ◽  
Leaf Succulence ◽  
The Relationship

ABSTRACT Among the effects of environmental change, the intensification of drought events is noteworthy, and tropical vegetation is predicted to be highly vulnerable to it. However, it is not clear how tropical plants in drought-prone habitats will respond to this change. In a coastal sandy plain environment, we evaluated the response of six plant species to water deficits across seasons, the relationship between their morpho-physiological traits, and which traits would be the best descriptors of plants' response to drought. Regardless of leaf succulence and phenology, responses between seasons were most strongly related to chlorophyll fluorescence. In this study we have demonstrated that a better comprehension of how tropical species from drought-prone habitats cope with changes in water availability can be based on seasonal variation in leaf water potential and chlorophyll fluorescence. Temporal variation in leaf water potential and chlorophyll fluorescence was found useful for differentiating between groups of sandy soil species that are responsive or unresponsive to water availability. However, chlorophyll fluorescence appeared to be a more sensitive descriptor of their seasonal and short-term responses.

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