Tropical forests store large amounts of biomass despite they generally grow in nutrient-poor soils, suggesting that the role of soil characteristics in the structure and dynamics of tropical forests is complex. We used data for >34 000 trees from several permanent plots in French Guiana to investigate if soil characteristics could predict the structure (tree diameter, density and aboveground bi...

The isotopic signatures of 15N and 18O in N2O emitted from tropical soils vary both spatially and temporally, leading to large uncertainty in the overall tropical source signature and thereby limiting the utility of isotopes in constraining the global N2O budget. Determining the reasons for spatial and temporal variations in isotope signatures requires that we know the isotope enrichment factor...

The tropics, sadly, continues to be a belt of poverty. The countries of the tropics all have low or middling incomes, with a few tiny or natural-resource-rich exceptions, and few of the poorest countries are outside of the tropics. The causes of tropical poverty are surely complex, involving initial endowments (Diamond), history, especially colonization, and geographical isolation (Gallup and S...

The response of tropical forests to global warming is one of the largest uncertainties in predicting the future carbon balance of Earth. To determine the likely effects of elevated temperatures on tropical forest understory plants and soils, as well as other ecosystems, an infrared (IR) heater system was developed to provide in situ warming for the Tropical Responses to Altered Climate Experime...

Humid tropical forests are generally characterized by the lack of nitrogen (N) limitation to net primary productivity, yet paradoxically have high potential for N loss. We conducted an intensive field experiment with NH4 and NO3 additions to highly weathered tropical forest soils in Puerto Rico to determine the relative importance of N retention and loss mechanisms. Over one-half of all the NH4...

Humid tropical forest soils are characterized by low and fluctuating redox, conditions which are thought to inhibit organic matter degradation by microbes. However, evidence suggests that soil microbial communities are adapted to the redox conditions in these ecosystems. In this study we tested the hypothesis that soil oxygen (O2) availability as an index of redox conditions structures patterns...

To study the biochar properties and its influence on Cu (II) adsorption, biochar was prepared from bagasse under the conditions of 350°C, 450°C and 550°C respectively, and biochar was added to three typical tropical soils (paddy soil, laterite and dry red soil). After mixed culture for 30 d, batch equilibrium experiment method was used to determine the effect of biochar on soil adsorption of Cu...

Carbon (C) sequestration, defined as the process whereby atmospheric CO2 is transferred into a long-lived C pool, is an important issue not only in the scientific community but also in the society at large because of its potential role in off-setting fossil fuel emissions. Through photosynthesis this C is stored in plants and through decomposition, trunks, branches, leaves and roots are incorpo...

The effect of soil properties like adsorption, desorption, movement and distribution of endosulfan (1, 2, 3, 4, 7, 7-hexachlorobicyclo (2, 2, 1)-2-heptene-5, 6-bisoxymethlene sulfite) in two tropical soils, sandy loam and sandy clay soil from Mysore, Karnataka state were studied respectively. The results indicated that soils with different physico-chemical properties have different effects on t...

[1] We studied soils on high-purity limestones of Quaternary age on the western Atlantic Ocean islands of Barbados, the Florida Keys, and the Bahamas. Potential soil parent materials in this region, external to the carbonate substrate, include volcanic ash from the island of St. Vincent (near Barbados), volcanic ash from the islands of Dominica and St. Lucia (somewhat farther from Barbados), th...