Tropical forests represent a major atmospheric carbon dioxide sink. Here the gross primary productivity (GPP) response of tropical rainforests to climate engineering via marine sky brightening under a future scenario is investigated in three Earth systemmodels. The model response is diverse, and in two of the three models, the tropical GPP shows a decrease from the marine sky brightening climat...

The response of tropical forests to climate change will depend on individual plant species' nutritional strategies, which have not been defined in the case of the nitrogen nutrition that is critical to sustaining plant growth and photosynthesis. We used isotope natural abundances to show that a group of tropical plant species with diverse growth strategies (trees and ferns, canopy, and subcanop...

[1] We report original data on nitrous oxide (N2O) fluxes from two tropical reservoirs, their rivers below the dam, and from natural aquatic ecosystems and rainforest soils in French Guiana and Panama. We also review published N2O fluxes from other tropical reservoirs and natural environments. We show that: (1) N2O emissions from tropical reservoirs occur mainly at the reservoir surface, fluxes...

The Amazon rainforest is well known for its rich plant and animal diversity, but its bacterial diversity is virtually unexplored. Due to ongoing and widespread deforestation followed by conversion to agriculture, there is an urgent need to quantify the soil biological diversity within this tropical ecosystem. Given the abundance of the phylum Verrucomicrobia in soils, we targeted this group to ...

The aluminum (Al) cation Al(3) (+) is highly rhizotoxic and is a major stress factor to plants on acid soils, which cover large areas of tropical and boreal regions. Many woody plant species are native to acid soils and are well adapted to high Al(3) (+) conditions. In tropical regions, both woody Al accumulator and non-Al accumulator plants occur, whereas in boreal regions woody plants are non...

Laurent Augusto (INRA) presented the current state of knowledge on the relationship between forest management policies and the maintenance of soil fertility based on the results of the RESOBIO(1) project (Landmann & Nivet, 2014) which studied the management of harvesting residues and the preservation of soils and biodiversity. Laurent Saint-André (INRA) gave a special presentation on the manage...

Tropical forest soils decompose litter rapidly with frequent episodes of anoxia, making it likely that bacteria using alternate terminal electron acceptors (TEAs) such as iron play a large role in supporting decomposition under these conditions. The prevalence of many types of metabolism in litter deconstruction makes these soils useful templates for improving biofuel production. To investigate...

DICK J., SKIBA U. & WILSON J. 2001. The effect of rainfall on NO and N2O emissions from Ugandan agroforest soils. Phyton (Horn, Austria) 41 (3): (73) (80). Agroforestry systems, often incorporating N-fixing trees, are widely used in tropical countries. However, the effect of such systems on the emissions of atmospheric pollutants NO and N2O is largely unknown. Here we compare the emissions from...

Although generally considered, with few exceptions, to be restricted to the acidic, tropical soils of the southern hemisphere, Beijerinckia species, resembling B. indica, were found at three sites on Devon Island (75 degrees 33'N, 84 degrees 40'W) in the Canadian Arctic.

Climate change is affecting the amount and complexity of plant inputs to tropical forest soils. This is likely to influence the carbon (C) balance of these ecosystems by altering decomposition processes e.g., "positive priming effects" that accelerate soil organic matter mineralization. However, the mechanisms determining the magnitude of priming effects are poorly understood. We investigated p...