scholarly journals Biogeochemical recuperation of lowland tropical forest during succession

Ecology ◽  
2019 ◽  
Vol 100 (4) ◽  
pp. e02641 ◽  
Author(s):  
Benjamin W. Sullivan ◽  
Rachel L. Nifong ◽  
Megan K. Nasto ◽  
Silvia Alvarez‐Clare ◽  
Camie M. Dencker ◽  
...  
Keyword(s):  
Tropical Forest ◽  
Lowland Tropical Forest

scholarly journals Monitoring Vegetation Change in the Presence of High Cloud Cover with Sentinel-2 in a Lowland Tropical Forest Region in Brazil

2020 ◽  
Vol 12 (11) ◽  
pp. 1829
Author(s):  
Tatiana Nazarova ◽  
Pascal Martin ◽  
Gregory Giuliani
Keyword(s):  
Tropical Forest ◽  
Temporal Resolution ◽  
Cloud Cover ◽  
Detection System ◽  
Forest Degradation ◽  
High Cloud ◽  
Lowland Tropical Forest ◽  
Forest Region ◽  
Vegetation Loss ◽  
Sentinel 2

Forests play major roles in climate regulation, ecosystem services, carbon storage, biodiversity, terrain stabilization, and water retention, as well as in the economy of numerous countries. Nevertheless, deforestation and forest degradation are rampant in many parts of the world. In particular, the Amazonian rainforest faces the constant threats posed by logging, mining, and burning for agricultural expansion. In Brazil, the “Sete de Setembro Indigenous Land”, a protected area located in a lowland tropical forest region at the border between the Mato Grosso and Rondônia states, is subject to illegal deforestation and therefore necessitates effective vegetation monitoring tools. Optical satellite imagery, while extensively used for landcover assessment and monitoring, is vulnerable to high cloud cover percentages, as these can preclude analysis and strongly limit the temporal resolution. We propose a cloud computing-based coupled detection strategy using (i) cloud and cloud shadow/vegetation detection systems with Sentinel-2 data analyzed on the Google Earth Engine with deep neural network classification models, with (ii) a classification error correction and vegetation loss and gain analysis tool that dynamically compares and updates the classification in a time series. The initial results demonstrate that such a detection system can constitute a powerful monitoring tool to assist in the prevention, early warning, and assessment of deforestation and forest degradation in cloudy tropical regions. Owing to the integrated cloud detection system, the temporal resolution is significantly improved. The limitations of the model in its present state include classification issues during the forest fire period, and a lack of distinction between natural vegetation loss and anthropogenic deforestation. Two possible solutions to the latter problem are proposed, namely, the mapping of known agricultural and bare areas and its subsequent removal from the analyzed data, or the inclusion of radar data, which would allow a large amount of finetuning of the detection processes.

scholarly journals Tropical forest soil carbon stocks do not increase despite 15 years of doubled litter inputs

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Emma J. Sayer ◽  
Luis Lopez-Sangil ◽  
John A. Crawford ◽  
Laëtitia M. Bréchet ◽  
Ali J. Birkett ◽  
...  
Keyword(s):  
Organic Matter ◽  
Tropical Forest ◽  
Critical Role ◽  
Tropical Soils ◽  
Soil Geochemistry ◽  
Soil Minerals ◽  
Litter Addition ◽  
Lowland Tropical Forest ◽  
Tropical Forest Soil ◽  
Underlying Mechanisms

AbstractSoil organic carbon (SOC) dynamics represent a persisting uncertainty in our understanding of the global carbon cycle. SOC storage is strongly linked to plant inputs via the formation of soil organic matter, but soil geochemistry also plays a critical role. In tropical soils with rapid SOC turnover, the association of organic matter with soil minerals is particularly important for stabilising SOC but projected increases in tropical forest productivity could trigger feedbacks that stimulate the release of stored SOC. Here, we demonstrate limited additional SOC storage after 13–15 years of experimentally doubled aboveground litter inputs in a lowland tropical forest. We combined biological, physical, and chemical methods to characterise SOC along a gradient of bioavailability. After 13 years of monthly litter addition treatments, most of the additional SOC was readily bioavailable and we observed no increase in mineral-associated SOC. Importantly, SOC with weak association to soil minerals declined in response to long-term litter addition, suggesting that increased plant inputs could modify the formation of organo-mineral complexes in tropical soils. Hence, we demonstrate the limited capacity of tropical soils to sequester additional C inputs and provide insights into potential underlying mechanisms.

The productivity, metabolism and carbon cycle of two lowland tropical forest plots in south-western Amazonia, Peru

2013 ◽  
Vol 7 (1-2) ◽  
pp. 85-105 ◽  
Author(s):  
Yadvinder Malhi ◽  
Filio Farfán Amézquita ◽  
Christopher E. Doughty ◽  
Javier E. Silva-Espejo ◽  
Cécile A.J. Girardin ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Tropical Forest ◽  
Lowland Tropical Forest

scholarly journals The Piedra Chamana fossil woods and leaves: a record of the vegetation and palaeoenvironment of the Neotropics during the late middle Eocene

2020 ◽  
Vol 125 (7) ◽  
pp. 1077-1089
Author(s):  
Deborah W Woodcock ◽  
Herbert W Meyer
Keyword(s):  
Water Stress ◽  
Tropical Forest ◽  
Middle Eocene ◽  
Vessel Diameter ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Lowland Tropical Forest ◽  
Modern Analogue ◽  
Vessel Elements ◽  
Analytical Approaches

Abstract Background and Aims The Piedra Chamana fossil forest in northern Peru is an assemblage of angiosperm woods and leaves preserved in volcaniclastic rocks dated to 39 Mya (late Middle Eocene). We analysed the anatomical and morphological features of the fossils to reconstruct the palaeoenvironment during this time of global warmth, taking advantage of the co-occurrence of woods and leaves to compare different proxies and analytical approaches. Methods Wood characters analysed include vessel-related functional traits, traits linked to Baileyan trends, and quantitative features such as vessel diameter and density. Diameter-distribution and diameter and position plots are used to represent vessel diameter and arrangement. Leaf margin and area analysis provides additional climate estimates. Key Results The fossil woods show many similarities with modern tropical-forest woods and tropical fossil-wood assemblages; closest correspondence within the Neotropics is to semi-deciduous lowland tropical forest with moderate precipitation (~1000–1200 mm). Features unusual for the modern South American tropics are mainly vessel-related characters (semi-ring porosity, grouped vessels, helical vessel thickenings, short vessel elements) linked to water stress or seasonal water availability. Leaf analysis indicates mean annual temperature of 31 °C (n = 19, 100 % entire-margined) and mean annual precipitation of 1290 mm (n = 22, predominantly microphylls and notophylls). Conclusions The palaeovegetation was clearly lowland tropical forest with a dry aspect, but anomalous aspects of the wood anatomy are consistent with the high temperatures indicated by the leaves and are probably explained by differences in seasonality and water stress compared to the present-day Neotropics. A close modern analogue may be in very seasonal regions of Asia. Pronounced monsoonal (summer-rain) conditions may relate to a location (palaeolatitude of 13°S) outside the near-equatorial tropics.

scholarly journals Drivers of aboveground wood production in a lowland tropical forest of West Africa: teasing apart the roles of tree density, tree diversity, soil phosphorus, and historical logging

2016 ◽  
Vol 6 (12) ◽  
pp. 4004-4017 ◽  
Author(s):  
Tommaso Jucker ◽  
Aida Cuni Sanchez ◽  
Jeremy A. Lindsell ◽  
Harriet D. Allen ◽  
Gabriel S. Amable ◽  
...  
Keyword(s):  
West Africa ◽  
Tropical Forest ◽  
Soil Phosphorus ◽  
Tree Diversity ◽  
Tree Density ◽  
Wood Production ◽  
Lowland Tropical Forest

scholarly journals The Piedra Chamana fossil woods (Eocene, Peru), II

IAWA Journal ◽  
2019 ◽  
Vol 40 (3) ◽  
pp. 551-595 ◽  
Author(s):  
D.W. Woodcock ◽  
H.W. Meyer ◽  
Y. Prado
Keyword(s):  
Tropical Forest ◽  
Middle Eocene ◽  
Dry Forest ◽  
South American ◽  
Lowland Tropical Forest ◽  
Or Groups ◽  
Freshwater Swamp ◽  
Flooded Forests ◽  
Fossil Forest ◽  
Seasonally Flooded

ABSTRACTThis contribution presents descriptions of 14 fossil woods from the Piedra Chamana Fossil Forest in Peru, an assemblage of fossil woods and leaves dated at 39 Ma (late Middle Eocene). It is part two of the descriptions of the non-monocot angiosperm fossils from the site (see Woodcock et al. 2017). The woods are assigned to the subfamilies Bombacoideae, Bombacoideae/Malvoideae, Byttneroideae, Grewioideae, and Sterculioideae of Malvaceae and the families Melastomataceae, Muntingiaceae, Rubiaceae, Rutaceae, and Sapindaceae. Malvalean taxa make up around one-third of the wood types. Many of the woods are identifiable to modern-day genera or groups, including genera with species counted among the hyperdominant trees of the New World forests. Represented vegetation types include mixed freshwater swamp with Avicennia, seasonally flooded forest, and lowland tropical forest with a dry aspect. The assemblage shows floristic similarities to extant South American lowland tropical forest, particularly the seasonally flooded forests growing along white water rivers (várzea); however, the dry forest association has a less clear analog in the present-day tropics.

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