The changes in land use caused by antropogenic interventions, has increased the global pool of nutrients (Nitrogen and Phosphorus) in terrestrial and aquatic ecosystems. This report analyzes the behavior of the main nutrient biogeochemical cycles and the consequences of its alterations. It is remarkable the enhancement of some inputs and outputs to terrestrial and aquatic ecosystems and the inc...

Downward redistribution of soil water through plant roots has important consequences for water and nutrient balance of arid and semi-arid ecosystems. Nevertheless, information on the seasonal patterns and magnitudes of redistribution is lacking for all but a few plant species. We measured sap flow in the taproot and three main lateral roots of a 10-year-old Juglans major Torr. tree, on an ephem...

Strömgren, M. 2001. Soil-Surface CO2 Flux and Growth in a Boreal Norway Spruce Stand. Effects of soil warming and nutrition. Acta Universitatis Agriculturae Sueciae, Silvestria 220. Doctor's dissertation. ISSN 1401-6230, ISBN 91-576-6304-1. Global warming is predicted to affect the carbon balance of forests. A change in the carbon balance would give a positive or negative feedback to the greenh...

Large-scale changes in land use are occurring in many tropical regions, with significant impacts on nitrogen and phosphorus biogeochemistry. In this study we examine the relationships between land use, anthropogenic nutrient inputs, and riverine nutrient exports in a major agricultural watershed of the Pacific coast of South America, the Guayas River basin of Ecuador. We present comprehensive n...

In tropical forests with nutrient-rich soil tree's nutrient resorption from senesced leaves has not always been observed to be low. Perhaps this lack of consistence is partly owing to the nutrient resorption methods used. The aim of the study was to analyse N and P resorption proficiency from tropical rain forest trees in a nutrient-rich soil. It was hypothesised that trees would exhibit low nu...

BACKGROUND Arbuscular mycorrhizal fungi (AMF) provide numerous services to their plant symbionts. Understanding climate change effects on AMF, and the resulting plant responses, is crucial for predicting ecosystem responses at regional and global scales. We investigated how the effects of climate change on AMF-plant symbioses are mediated by soil water availability, soil nutrient availability, ...

The soil supports plants, is the physical determinant of root growth and extent, and is the main reservoir for plant-available water and nutrients. Therefore, the soil controls the availability of most essential plant nutrients. It regulates availability by means of biophysiochemical processes, which are functions of soil and plant properties. This chapter introduces the concept of soil nutrien...

Simple nitrogen (N) input/output balance calculations in agricultural systems are used to evaluate performance of nutrient management; however, they generally rely on extensive assumptions that do not consider leaching, denitrification, or annual depletion of soil N. We constructed a relatively complete N mass balance for the Big Ditch watershed, an extensively tile-drained agricultural watersh...

CONTENTS 3.1 Temperate Region Soil Differences .................................................................................. 28 3.2 Challenges to Soil Fertility and Management................................................................ 29 3.2.1 Soil Organic Matter Restoration and Conservation.......................................... 30 3.2.2 High Nutrient-Use Efficiency .................

The response of soil biogeochemical properties to external nutrient loading may serve as sensitive indicators of eutrophication in wetland ecosystems. We investigated the effects of nutrient loading on the distribution of soil C, N and P in four wetlands of the Florida Everglades: Water Conservation Area (WCA)-1, WCA-2a, WCA-3a and Taylor Slough. The nutrient-impacted zones extended from water-...