Buchbesprechungen

Ohne Zusammenfassung     

CO2-mitigation by agroforestry

Agroforestry is a very important option for C-fixation in the tropics because of the large area suitable for this practice. The amount of C directly sequestered by trees within the different agroforestry systems normally ranges from 3 to 25 t · ha^?1 and in some cases up to 60 t · ha^?1. Additional CO₂-mitigating effects can achieve more than 20 times this quantity. Such effects are:

the protection of existing forests.

the conservation of soil productivity.

the reduction of fossil energy consumption by use of timber instead of more energyintensive raw materials and

the substitution of fossil fuel by wood as an energy source.

     

Present role of German forests and forestry in the national carbon budget and options to its increase

The carbon stock in forests and wooden products is quantified for the Federal Republic of Germany. In addition the sink effects of ? the actual forests and ? the pool of wooden products are determined. The mitigation obtained by ? substitution of high energy raw materials by wood, ? substitution of fossil fuels by wood as source of energy were evaluated. Finally the C-ecological effects of the following silvicultural measures were quantified: ? lengthening of rotation time ? underplanting ? change of tree species ? afforestation of non forest land ? increased use of slash and wood from thinning operations as energy source.     

Untersuchungen in Buchenmastjahren

Ohne ZusammenfassungDie Arbeit wurde durch Forschungsbeihilfen der Deutschen Forschungsgemeinschaft sowie der Landesforstverwaltungen von Niedersachsen und Nordrhein-Westfalen ermöglicht.     

Contribution of temperate forests to the world's carbon budget

Temperate forests currently cover about 600 MHa, about half of their potential. Almost all these forests have been directly impacted by humans. The total living biomass in trees (including roots) was estimated to contain 33.7 Gt C. The total C pool for the entire forest biome was estimated as 98.8 Gt. The current net sink flux of biomass was calculated at 205 Mt yr^?1, with a similar amount removed in harvests for manufacture into various products. The major cause of this C sink is forest regrowth. Forest regrowth is possible because fossil fuels are the major source of energy in temperate countries, instead of fuelwood. Future C in these forests will be greatly influenced by human activity. Options to sequester more C include conservation of forest resources, activities that increase forest productivity such as adopting rotation ages to optimize C production, afforestation, improvement of wood utilization, and waste management.