first signs of carbon sink saturation in european forest ......on knaw document trouw, 21 january ....
TRANSCRIPT
First signs of carbon sink saturation in
European forest biomass
Gert-Jan Nabuurs
Professor European forest resources
Based on NCC 18 Aug 2013, with Marcus Lindner,
Hans Verkerk, Roman Michalak, Paola deda,
Giacomo Grassi, Katja Gunia
1. Introduction to European forests
2.Challenges in European forests that determine the C balance
3.Latest trends in C sink in forest biomass
4.Conclusions and new projections
1. Introduction to European forests
1x1 km, tree spp map (Hengeveld et al.2012; Brus et al. 2012 )
Northern hemispheric vegetation rebound
Large diversity in man-made systems
Supplying many goods.....
....and services for the urbanised society
Value of environmental services is ~3000 $ /ha.y
(De Groot 2012 )
Present state of European forests
Forest and other wooded land area: 178 Mha forest in EU27 countries, all actively managed;
Afforestation 0.5 Mha/y
Net increment: 4.7 m3 ha-1 y-1 , increased from 1950 to 2005
Volume: 153 m3 ha-1 and increasing
More than half coniferous
UN-ECE/FAO 2011, EFSOS II
2. challenges in European forests that
determine the C balance
Forests are ageing
Share of the forest at an age > 120 years. Vilen et al. 2012
Ever higher growing stocks lead to increased disturbances
Volume of damage
(schelhaas et al 2003)
Biodiversity decline
Common forest birds (EEA 2008)
Contribution of forest sector to country level GDP is minimal (UNECE/FAO 2011)
More challenges….
Weighted average size of forest holding for the EU = 2.7 ha/holding
Most recent trends in the sector - A sector under pressure, looking for new products
Production of paper and paperboard in Europe (UNECE 2013)
Pellets mostly from Canada, USA, Russia
Nanocellulose based polymers
Biomass: fiercely discussed
Volkskrant 13 January, based
on KNAW document
Trouw, 21 January
3. Latest trends in C sink in forest biomass
Methods
data analysis
Compiling/analysing main drivers, main trends as increment, harvest
Mostly based on national forest inventory data
Forest sector data (harvest)
Disturbance trends
Land use change data
UNFCCC reports
First time since 1960 that increment is
declining
Harvest has gone up as well, but stays behind
Rate of carbon sequestration in forest biomass
is curbing
Nabuurs et al. 2013
Regionally significant differences
Causes
Decline in increment of the mature forest and an increasing harvest — further enhanced by deforestation and by increased natural disturbances — seem to be causing the curbing of the sink strength
Decline in increment partly caused by an ageing forest, and an highly stocked forest
Climate-induced declines in productivity
4. Recommendations and new projections
Conserve high carbon-stock densities in old forests that are not at
a high risk of disturbance
Harvest mature forests that are at high risk of disturbance and
already have low productivity.
Probably time to stimulate a more rational forest management in
certain regions ..while paying due attention to other services
Optimize silvicultural techniques to arrive at a carbon-efficient
management scheme in forests that are grown primarily for
timber,
intensify management where the primary goal is biomass for
bioenergy
Continue afforestation schemes in Europe — particularly while
concomitantly curbing gross deforestation.
Forest NBP (2000-2005) C stock change in trees and soil
Eggers et al. 2008
EFISCEN: Providing insight in carbon balance,
and e.g. wood availability
Management can change the trend: gradual conversion of European forests to plantations
Nabuurs et al. 2014
Projecting the sink: We need to think
about a more spatially disaggregated
forest management across Europe ..
Hengeveld et al. 2012
Developing a high resolution modelling
approach based > 300,000 NFI plot data
from across Europe. Thanks to NFIs.
Levers et al. 2014, Verkerk et al In press
Large parts are hardly used/managed
