Survey of technical and management-based mitigation measures in forestry

Forests contribute considerably to the terrestrial carbon sink. Although the speed of uptake is generally low, the stocks in both biomass and soil are high. Within the Kyoto Protocol, active forest management can be used to reach the goals for emission reduction. In this report, an extensive list of measures is compiled detailing the ways in which forestry could contribute to an enhanced sink, or could reduce emissions. Most measures in forest management will have small effects, and these effects will generally only become visible in the long term. Effective measures can be divided into three categories; firstly, those that protect existing carbon stocks. Such measures include avoiding deforestation, not harvesting stands with high carbon contents, increased fire prevention and minimising site preparation. Secondly, those that aim to increase average carbon stocks, such as afforestation, conversion to continuous cover forestry and changes in rotation length. The third category are measures that aim at harvesting biomass to create bioenergy. Such measures could be the use of logging residues, increasing the amount of fellings aimed at bioenergy wood, the (re)introduction of pre-commercial thinnings, and the establishment of short rotation coppice

Meson-induced correlations of nucleons in nuclear Compton scattering

The non-resonant (seagull) contribution to the nuclear Compton amplitude at low energies is strongly influenced by nucleon correlations arising from meson exchange. We study this problem in a modified Fermi gas model, where nuclear correlation functions are obtained with the help of perturbation theory. The dependence of the mesonic seagull amplitude on the nuclear radius is investigated and the influence of a realistic nuclear density on this amplitude is dicussed. We found that different form factors appear for the static part (proportional to the enhancement constant $\kappa$) of the mesonic seagull amplitude and for the parts, which contain the contribution from electromagnetic polarizabilities.Comment: 15 pages, Latex, epsf.sty, 9 eps figures

Meer hout uit het Nederlandse bos

De vraag naar hout stijgt, maar dat vertaalt zich vooralsnog niet naar een grotere oogst in de Nederlandse bossen. Deels komt dat omdat het niet past bij de doelstelling van sommige bossen. Maar deels ligt het waarschijnlijk ook aan een gebrek aan interesse bij kleine boseigenaren

CO2FIX V2.0 : manual of a modeling framework for quantifying carbon sequestration in forest ecosystems and wood products

This reports presents a manual of the CO2FIX V 2.0 model. CO2FIX V 2.0 is a simple bookkeeping model that converts volumetric net annual increment data (and additional parameters) to annual carbon stocks and fluxes of the forest ecosystem-soil-wood products chain. It calculates on the hectare scale with time steps of one year. This Version 2.0 is a hectare scale model which was improved on the ability to simulate multi-species and uneven aged stands in multiple cohorts (e.g. selective tropical selective logging systems, and agroforestry systems); the ability to parametrize the growth also by stand density; the ability to deal with inter cohort competition; harvesting, allocation, processing lines, and end-of-life disposal of harvested wood; soil dynamics; the ability to deal with a wider variety of forest types including agro-forestry systems, selective logging systems, and post harvesting mortality; output viewing charts

Meningeal lymphatic endothelial cells fulfill scavenger endothelial cell function and cooperate with microglia in waste removal from the brain

Brain lymphatic endothelial cells (BLECs) constitute a group of loosely connected endothelial cells that reside within the meningeal layer of the zebrafish brain without forming a vascular tubular system. BLECs have been shown to readily endocytose extracellular cargo molecules from the brain parenchyma, however, their functional relevance in relation to microglia remains enigmatic. We here compare their functional uptake efficiency for several macromolecules and bacterial components with microglia in a qualitative and quantitative manner in 5-day-old zebrafish embryos. We find BLECs to be significantly more effective in the uptake of proteins, polysaccharides and virus particles as compared to microglia, while larger particles like bacteria are only ingested by microglia but not by BLECs, implying a clear distribution of tasks between the two cell types in the brain area. In addition, we compare BLECs to the recently discovered scavenger endothelial cells (SECs) of the cardinal vein and find them to accept an identical set of substrate molecules. Our data identifies BLECs as the first brain-associated SEC population in vertebrates, and demonstrates that BLECs cooperate with microglia to remove particle waste from the brain.Thrombosis and Hemostasi

Entry of Human Papillomavirus Type 16 by Actin-Dependent, Clathrin- and Lipid Raft-Independent Endocytosis

Infectious endocytosis of incoming human papillomavirus type 16 (HPV-16), the main etiological agent of cervical cancer, is poorly characterized in terms of cellular requirements and pathways. Conflicting reports attribute HPV-16 entry to clathrin-dependent and -independent mechanisms. To comprehensively describe the cell biological features of HPV-16 entry into human epithelial cells, we compared HPV-16 pseudovirion (PsV) infection in the context of cell perturbations (drug inhibition, siRNA silencing, overexpression of dominant mutants) to five other viruses (influenza A virus, Semliki Forest virus, simian virus 40, vesicular stomatitis virus, and vaccinia virus) with defined endocytic requirements. Our analysis included infection data, i.e. GFP expression after plasmid delivery by HPV-16 PsV, and endocytosis assays in combination with electron, immunofluorescence, and video microscopy. The results indicated that HPV-16 entry into HeLa and HaCaT cells was clathrin-, caveolin-, cholesterol- and dynamin-independent. The virus made use of a potentially novel ligand-induced endocytic pathway related to macropinocytosis. This pathway was distinct from classical macropinocytosis in regards to vesicle size, cholesterol-sensitivity, and GTPase requirements, but similar in respect to the need for tyrosine kinase signaling, actin dynamics, Na+/H+ exchangers, PAK-1 and PKC. After internalization the virus was transported to late endosomes and/or endolysosomes, and activated through exposure to low pH

Winter respiratory C losses provide explanatory power for net ecosystem productivity

Accurate predictions of net ecosystem productivity (NEPc) of forest ecosystems are essential for climate change decisions and requirements in the context of national forest growth and greenhouse gas inventories. However, drivers and underlying mechanisms determining NEPc (e.g., climate and nutrients) are not entirely understood yet, particularly when considering the influence of past periods. Here we explored the explanatory power of the compensation day (cDOY)defined as the day of year when winter net carbon losses are compensated by spring assimilationfor NEPc in 26 forests in Europe, North America, and Australia, using different NEPc integration methods. We found cDOY to be a particularly powerful predictor for NEPc of temperate evergreen needleleaf forests (R-2=0.58) and deciduous broadleaf forests (R-2=0.68). In general, the latest cDOY correlated with the lowest NEPc. The explanatory power of cDOY depended on the integration method for NEPc, forest type, and whether the site had a distinct winter net respiratory carbon loss or not. The integration methods starting in autumn led to better predictions of NEPc from cDOY then the classical calendar method starting 1 January. Limited explanatory power of cDOY for NEPc was found for warmer sites with no distinct winter respiratory loss period. Our findings highlight the importance of the influence of winter processes and the delayed responses of previous seasons' climatic conditions on current year's NEPc. Such carry-over effects may contain information from climatic conditions, carbon storage levels, and hydraulic traits of several years back in time.Peer reviewe