Human alteration of the global nitrogen and phosphorus soil balances for the period 1970-2050

The Millennium Ecosystem Assessment scenarios for 2000 to 2050 describe contrasting future developments in agricultural land use under changing climate. Differences are related to the total crop and livestock production and the efficiency of nutrient use in agriculture. The scenarios with a reactive approach to environmental problems show increases in agricultural N and P soil balances in all developing countries. In the scenarios with a proactive attitude, N balances decrease and P balances show no change or a slight increase. In Europe and North America, the N balance will decline in all scenarios, most strongly in the environment-oriented scenarios; the P balance declines (proactive) or increases slowly (reactive approach). Even with rapidly increasing agricultural efficiency, the global N balance, ammonia, leaching and denitrification loss will not decrease from their current levels even in the most optimistic scenario. Soil P depletion seems to be a major problem in large parts of the global grassland are

Anthropogenic nitrogen autotrophy and heterotrophy of the world's watersheds: Past, present, and future trends

Anthropogenic nitrogen autotrophy of a territory is defined as the nitrogen flux associated with local production of harvested crops and grass consumed by livestock grazing (in kg N/km(2)/yr). Nitrogen heterotrophy is the nitrogen flux associated with local food and feed consumption by humans and domestic animals. These two summarizing characteristics (anthropogenic nitrogen autotrophy and heterotrophy (ANAH)) indicate the degree of anthropogenic perturbation of the nitrogen cycle by agriculture and human consumption: their balance value provides information on either the potential for commercial export or the need to import agricultural goods; in a watershed, their vector sum is related to the nitrogen flux delivered to the sea. These indicators were calculated for all the watersheds in the Global Nutrient Export from Watersheds (NEWS) database for 1970 and 2000, as well as for 2030 and 2050, according to Millennium Ecosystem Assessment scenarios. During this 30 year period, many watersheds shifted from relatively balanced situations toward either more autotrophic or more heterotrophic conditions. This trend is predicted to become more pronounced over the next 50 year

Global nitrogen and phosphate in urban wastewater for the period 1970 to 2050

This paper presents estimates for global N and P emissions from sewage for the period 1970-2050 for the four Millennium Ecosystem Assessment scenarios. Using country-specific projections for population and economic growth, urbanization, development of sewage systems, and wastewater treatment installations, a rapid increase in global sewage emissions is predicted, from 6.4 Tg of N and 1.3 Tg of P per year in 2000 to 12.0-15.5 Tg of N and 2.4-3.1 Tg of P per year in 2050. While North America (strong increase), Oceania (moderate increase), Europe (decrease), and North Asia (decrease) show contrasting developments, in the developing countries, sewage N and P discharge will likely increase by a factor of 2.5 to 3.5 between 2000 and 2050. This is a combined effect of increasing population, urbanization, and development of sewage systems. Even in optimistic scenarios for the development of wastewater treatment systems, global N and P flows are not likely to declin

N:P:Si nutrient export ratios and ecological consequences in coastal seas evaluated by the ICEP approach

The Indicator for Coastal Eutrophication Potential (ICEP) for river nutrient export of nitrogen, phosphorus, and silica at the global scale was first calculated from available measurement data. Positive values of ICEP indicate an excess of nitrogen and phosphorus over silica and generally coincide with eutrophication. The sign of ICEP based on measured nutrient fluxes was in good agreement with the corresponding one calculated from the Global-NEWS models for more than 5000 watersheds in the world. Calculated ICEP for the year 2050 based on Global NEWS data for the four Millennium Ecosystem Assessment scenarios show increasing values particularly in developing countries. For further evaluation of the ICEP at the outlet of the rivers of the world based on measurements, there is a need for additional determination silica fluxes and concentrations, which are scarcely documented

The BIOEXPLOIT Project

The EU Framework 6 Integrated Project BIOEXPLOIT concerns the exploitation of natural plant biodiversity for the pesticide-free production of food. It focuses on the pathogens Phytophthora infestans, Septoria tritici, Blumeria graminis, Puccinia spp. and Fusarium spp. and on the crops wheat, barley, tomato and potato. The project commenced in October 2005, comprises 45 laboratories in 12 countries, and is carried out by partners from research institutes, universities, private companies and small-medium enterprises. The project has four strategic objectives covered in eight sub-projects. These objectives relate to (i) understanding the molecular components involved in durable disease resistance, (ii) exploring and exploiting the natural biodiversity in disease resistance, (iii) accelerating the introduction of marker-assisted breeding and genetic engineering in the EU plant breeding industry, and (iv) coordinating and integrating resistance breeding research, providing training in new technologies, disseminating the results, and transferring knowledge and technologies to the industry

Laboratory gas-phase infrared spectra of two astronomically relevant PAH cations: diindenoperylene, C32_{32}H16_{16}+^+ and dicoronylene, C48_{48}H20_{20}+^+

The first gas-phase infrared spectra of two isolated astronomically relevant and large PAH cations - diindenoperylene (DIP) and dicoronylene (DC) - in the 530$-$1800 cm$^{-1}$ (18.9$-$5.6 $\mu$m) range - are presented. Vibrational band positions are determined for comparison to the aromatic infrared bands (AIBs). The spectra are obtained via infrared multiphoton dissociation (IRMPD) spectroscopy of ions stored in a quadrupole ion trap (QIT) using the intense and tunable radiation of the free electron laser for infrared experiments (FELIX). DIP$^{+}$ shows its main absorption peaks at 737 (13.57), 800 (12.50), 1001 (9.99), 1070 (9.35), 1115 (8.97), 1152 (8.68), 1278 (7.83), 1420 (7.04) and 1550 (6.45) cm$^{-1}$($\mu$m), in good agreement with DFT calculations that are uniformly scaled to take anharmonicities into account. DC$^+$ has its main absorption peaks at 853 (11.72), 876 (11.42), 1032 (9.69), 1168 (8.56), 1300 (7.69), 1427 (7.01) and 1566 (6.39) cm$^{-1}$($\mu$m), that also agree well with the scaled DFT results presented here. The DIP$^+$ and DC$^+$ spectra are compared with the prominent infrared features observed towards NGC 7023. This results both in matches and clear deviations. Moreover, in the 11.0$-$14.0 $\mu$m region, specific bands can be linked to CH out-of-plane (oop) bending modes of different CH edge structures in large PAHs. The molecular origin of these findings and their astronomical relevance are discussed

Molecular Signatures in the Near Infrared Dayside Spectrum of HD 189733b

We have measured the dayside spectrum of HD 189733b between 1.5 and 2.5 microns using the NICMOS instrument on the Hubble Space Telescope. The emergent spectrum contains significant modulation, which we attribute to the presence of molecular bands seen in absorption. We find that water (H2O), carbon monoxide (CO), and carbon dioxide (CO2) are needed to explain the observations, and we are able to estimate the mixing ratios for these molecules. We also find temperature decreases with altitude in the ~0.01 < P < ~1 bar region of the dayside near-infrared photosphere and set an upper limit to the dayside abundance of methane (CH4) at these pressures.Comment: 13 pages, 3 figures. accepted in Astrophysical Journal Letter

The absence of the 10 um silicate feature in the isolated Herbig Ae star HD 100453

We analyse the optical and IR spectra, as well as the spectral energy distribution (UV to mm) of the candidate Herbig Ae star HD100453. This star is particular, as it shows an energy distribution similar to that of other isolated Herbig Ae/Be stars (HAEBEs), but unlike most of them, it does not have a silicate emission feature at 10 um, as is shown in Meeus (2001). We confirm the HAEBE nature of HD100453 through an analysis of its optical spectrum and derived location in the H-R diagram. The IR spectrum of HD100453 is modelled by an optically thin radiative transfer code, from which we derive constraints on the composition, grain-size and temperature distribution of the circumstellar dust. We show that it is both possible to explain the lack of the silicate feature as (1) a grain-size effect - lack of small silicate grains, and (2) a temperature effect - lack of small, hot silicates, as proposed by Dullemond (2001), and discuss both possibilities.Comment: 9 pages, 7 figures; accepted by A&