Above.ground woody biomass allocation and within tree carbon and nutnent distribution of wild cherry （Prunus aviurn L.） a case study

摘要

Background:The global search for new ways to sequester carbon has already reached agricultural lands.Such land constitutes a major potential carbon sink.The production of high value timber within agroforestry systems can facilitate an in-situ carbon storage function.This is followed by a potential long term ex- situ carbon sinkwithin long lasting products such as veneer and furniture.For this purpose wild cherry(Prunus avium L.) is an interesting option for middle Europe,yielding high prices on the timber market.Methods:A total number of 39 wild cherry were sampled in 2012 and 2013 to assess the leafless above ground biomass.The complete trees including stem and branches were separated into 1 cm diameter classes.Wood and bark from sub-samples were analysed separately and nutrient content was derived.Models for biomass estimation were constructed for all tree compartments.Results:The smallest diameter classes possess the highest proportion of bark due to smaller cross sectional area.Tree boles with a greater amount of stem wood above 10 cm in diameter will have a more constant bark proportion.Total branch bark proportion also remains relatively constant above d_(1.3m) measurements of 8 cm.A balance is evident between the production of new branches with a low diameter and high bark proportion offset by the thickening and a relative reduction in bark proportion in larger branches.The results show that a single tree with an age of 17 and 18 years can store up to 85 kg of carbon within the aboveground biomass portion,an amount that will increase as the tree matures.Branches display greater nutrient content than stem sections per volume unit which can be attributed to a greater bark proportion.Conclusions:Using the derived models the carbon and the nutrient content of above-ground woody biomass of whole trees can be calculated.Suggested values for carbon with other major and minor nutrients held within relatively immature trees strongly supports the idea of the inclusion of wild cherry within agroforestry systems as an option for carbon sequestration.