ArticlePDF Available

Old-growth forests as global carbon sinks. Nature

January 2008

Authors:

Sebastiaan Luyssaert

Vrije Universiteit Amsterdam

Schulze Ernst Detlef

Max Planck Institute for Biogeochemistry Jena

Alexander Knohl

Georg-August-Universität Göttingen

Show all 8 authorsHide

Content uploaded by Beverly E Law

Content may be subject to copyright.

LETTERS

Old-growth forests as global carbon sinks

Sebastiaan Luyssaert

1,2

, E. -Detlef Schulze

, Annett Bo

¨rner

, Alexander Knohl

, Dominik Hessenmo

¨ller

Beverly E. Law

, Philippe Ciais

& John Grace

Old-growth forests remove carbon dioxide from the atmosphere

1,2

at rates that vary with climate and nitrogen deposition

. The seques-

tered carbon dioxide is stored in live woody tissues and slowly

decomposing organic matter in litter and soil

.Old-growthforests

therefore serve as a global carbon dioxide sink, but they are not

protected by international treaties, because it is generally thought

that ageing forests cease to accumulate carbon

5,6

.Herewereporta

search of literature and databases for forest carbon-flux estimates.

We find that in forests between 15 and 800 years of age, net ecosys-

tem productivity (the net carbon balance of the forest including

soils) is usually positive. Our results demonstrate that old-growth

forests can continue to accumulate carbon, contrary to the long-

standing view that they are carbon neutral. Over 30 per cent of the

global forest area is unmanaged primary forest, and this area con-

tains the remaining old-growth forests

. Half of the primary forests

(6 310

hectares) are located inthe boreal and temperate regions of

the NorthernHemisphere. On the basis ofour analysis, these forests

alone sequester about 1.3 60.5 gigatonnesof carbon per year. Thus,

our findings suggest that 15 per cent of the global forest area, which

is currently not considered when offsetting increasing atmospheric

carbon dioxide concentrations, provides at least 10 per cent of the

global net ecosystem productivity

. Old-growth forests accumulate

carbon for centuries and contain large quantities of it. We expect,

however, thatmuch of this carbon, even soil carbon

, will move back

to the atmosphere if these forests are disturbed.

We conducted a literature search to test the hypothesis that old-

growth forests continue to accumulate atmospheric carbon dioxide

(CO

). Site-level estimates of the annual sums of carbon-cycle com-

ponents were compiled, including those of biometry-based net prim-

ary production (NPP), eddy-covariance or biometry-based net

ecosystem production (NEP) and chamber-based heterotrophic res-

piration. The data set was completed with site information related to

stand characteristics, standing biomass and stand age. Data were com-

piled from 519 plot studies that reported one or more components of

the carbon cycle. The studies involved boreal (,30%) and temperate

(,70%) forests and represented the full range of conditions of such

forests, excluding those subjected to experimental treatments such as

fertilization and irrigation (Supplementary Information, section 1.1).

Tropical forests were excluded from the analysis because only 12 sites

were found for which NEP and age estimates are available.

The NEP is the net carbon balance of the forest as a whole, and is

the difference between CO

uptake by assimilation and losses

through plant and soil respiration. On the basis of our global data

set we find that in forests between 15 and 800 years old, the NEP is

usually positive; that is, the forests are CO

sinks (Fig. 1a). The

maximum probabilities of finding a single forest to be a source of

carbon at 60, 180 and 300 years of age are 0.20, 0.25 and 0.35,

respectively. However, the probability of finding an ensemble of

ten old-growth forests that are carbon neutral is negligible

(Supplementary Fig. 1). In the small number of case studies on the

effect of age on the carbon balance of forests, several have demon-

strated some age-related decline in NEP but very few have shown old

forests to be sources

1,2,10–13

. Our NEP estimates suggest that forests

200 years old and above sequester on average 2.4 60.8 tC ha

(tC, tonnes of carbon; Fig. 1a). In our model (Supplementary

Information, section 1.3), we find that old-growth forests accumulate

0.4 60.1 tC ha

in their stem biomass and 0.7 6

0.2 tC ha

in coarse woody debris, which implies that about

1.3 60.8 tC ha

of the sequestered carbon is contained in roots

and soil organic matter.

The commonly accepted and long-standing view that old-growth

forests are carbon neutral (that is, that photosynthesis is balanced by

respiration) was advanced in ref. 6 and was originally based on ten

years’ worth of data from a single site

. It is supported by the observed

decline of stand-level NPP with age in plantations

14,15

, but is not

apparent in some ecoregions

. Yet a decline in NPP is commonly

assumed in ecosystem models (Supplementary Information, section

1.4). Moreover, it has led to the view that old-growth forests are

redundant in the global carbon cycle.

If, however, the hypothesis of carbon neutrality

were correct, the

expected probabilities of observing a sink or source would be equal

and around one-half, the average sink strength for a random

ensemble of forests 200 years old and above would be zero and the

mean CO

release from heterotrophic respiration would equal the

mean CO

sequestration through NPP (thus, the ratio of hetero-

trophic respiration to NPP would be approximately one).

However, we observe this ratio to be well below one on average

(Fig. 1b) and not to increase with age. Hence, all three quantitative

tests fail to support the hypothesis of carbon neutrality. The currently

available data consistently indicate that carbon accumulation con-

tinues in forests that are centuries old.

In fact, young forests rather than old-growth forests are very often

conspicuous sources of CO

(Fig. 1a) because the creation of new

forests (whether naturally or by humans) frequently follows disturb-

ance to soil and the previous vegetation, resulting in a decomposition

rate of coarse woody debris, litter and soil organic matter (measured

as heterotrophic respiration) that exceeds the NPP of the

regrowth

2,17–22

(Fig. 1b).

The scatter in the relationship between NPP and age is consid-

erable, but given the climatic, edaphic and biological diversity of the

observations in combination with differences in disturbance histor-

ies, this is to be expected. There is some degree of age-related decline

in NPP beyond 80 years of age (Fig. 1c), and temperate and boreal

forests both show a consistent pattern of declining NPP beyond an

early maximum (Supplementary Fig. 2a) when analysed separately.

The decline in NPP could be partly attributed to the presence or

absence of management (Supplementary Fig. 2b). However, we

expect that this decline is not strictly a management effect, but a

Department of Biology, University of Antwerp, 2610 Wilrijk, Belgium.

College of Forestry, Oregon State University, Corvallis, Oregon 97331-5752 , USA.

Max-Planck Institute for

Biogeochemistry, 07701 Jena, Germany.

ETH Zu¨rich, Institute of Plant Sciences, CH-8092 Zu¨rich, Switzerland.

Laboratoire des Sciences du Climat et de l’Environnement, IPSL-LSC E,

CEA-CNRS-UVSQ, 91191 Gif sur Yvette Cedex, France.

School of GeoSciences, The University of Edinburgh, Edinburgh EH9 3JN, UK.

Vol 455

11 September 2008

doi:10.1038/nature07276

213

reflection of differences in disturbance history between managed and

unmanaged forests.

Consistent with earlier studies

, biomass continues to increase for

centuries irrespective of whether forests are boreal or temperate

(Supplementary Fig. 3). In the course of succession, plants compete

for resources and self-thinning

(or thinning by humans in the case

of managed forests) occurs (Fig. 2), so the older stands contain a

relatively small number of individuals, although of course these trees

tend to be large. Obviously biomass cannot accumulate forever. Our

data (Supplementary Fig. 3) suggest a possible upper limit some-

where between 500 and 700 tC ha

(equivalent to 1,400 to 1,800

cubic metres of wood per hectare); these high-biomass forests were

located in the Pacific Northwest USA

We speculate that when high above-ground biomass is reached,

individual trees are lost because of lightning, insects, fungal attacks of

the heartwood by wood-decomposers, or trees becoming unstable in

strong wind because the roots can no longer anchor them. If old-

growth forests reach high above-ground biomass and lose individuals

owing to competition or small-scale disturbances, there is generally

new recruitment or an abundant second canopy layer waiting in the

shade of the upper canopy to take over and maintain productivity.

Although tree mortality is a relatively rapid event (instantaneous

to several years long), decomposition of tree stems can take decades.

Therefore, the CO

release from the decomposition of dead wood

adds to the atmospheric carbon pool over decades, whereas natural

regeneration or in-growth occurs on a much shorter timescale. Thus,

old-growth forest stands with tree losses do not necessarily become

carbon sources, as has been observed in even-aged plantations (that

is, where trees are all of the same age). We recognize that self-thinning

theory was originally developed and validated for even-aged single-

species stands; however, it has been shown to hold for uneven-aged

multi-species plant communities (Supplementary Information, sec-

tion 1.3). In reasonable agreement with our observations (Fig. 1b),

self-thinning theory predicts that the ratio between heterotrophic

respiration and NPP is constant and around 0.65 60.02 (indicating

a carbon sink; Supplementary Fig. 4), as long as stand density is

driven by small-scale, rather than stand-replacing, disturbances.

Old stands, with sufficiently high densities (that is, through develop-

ment of a multilayer canopy structure) are thus expected to maintain

biomass accumulation for centuries. Hence, we postulate that bio-

mass accumulation and decline are largely driven by stand structure.

A stand must be spared for centuries from stand-replacing distur-

bances (such as fires, insect outbreaks, wind-throw and avalanches)

in order to accumulate sufficient aboveground biomass to become

old growth. Because the cumulative probability of disturbances is

higher in stands with high above-ground biomass, old stands are

rarer than young stands, even in unmanaged landscapes. At the land-

scape level, we expect a mosaic of forests characterized by different

times since the last stand-replacing disturbance

. Despite differences

in age and density, these forests are, however, expected to follow the

same relationship between biomass and density (Fig. 2).

−4

NEP (tC ha–1 yr –1)

Rh:NPP

1 3 10 31 100 315 1,000

Age (years)

NPP (tC ha–1 yr –1)

Figure 1

Changes in carbon fluxes as a function of age. a, Observed NEP

versus age; positive values indicate carbon sinks and negative values indicate

carbon sources. b, Observed ratio of heterotrophic respiration (Rh) to NPP

versus age; Rh:NPP ,1 indicates a carbon sink. c, Observed NPP versus age.

It appears that temperate and boreal forests both show a pattern of declining

NPP. Most probably, the late-successional increase in NPP is caused by the

combination of data from different climate regions or the combination of

disturbance regimes (Supplementary Fig. 2a, b). In each panel, the green

dots show observations of temperate forests, the orange dots show

observations of boreal forests, the thick black line shows the weighted mean

within a moving window of 15 observations, the grey area around this line

shows the 95% confidence interval of the weighted mean and the thin black

lines delineate the 95% confidence interval (where visible) of the individual

flux observations.

100 315 1,000 3,150 10,000 31,500

100

1,000

Density (trees per hectare)

Biomass (tC ha–1)

Figure 2

Biomass accumulation as a function of stand density. Each data

point represents a different forest, many of which have different growing

conditions and tree species. Not all growing conditions and species

compositions allow for the accumulation of the global maximum observed

biomass. Self-thinning, the process of density-dependent mortality, is shown

(solid line, of slope c) as the relationship between the logarithm of above-

ground biomass and the logarithm of stand density according to ref. 23

(c520.51 60.08, r

50.25, P,0.01). The green dots show observations of

temperate forests, the orange dots show observations of boreal forests and

the grey area (which is barely wider than the solid line) shows the 95%

confidence interval of the median.

LETTERS NATURE

Vol 455

11 September 2008

214

Under the Kyoto Protocol (http://unfccc.int/resource/docs/

convkp/kpeng.pdf) only anthropogenic effects on ecosystems are con-

sidered (Article 2 of the Framework Convention on Climate Change

(http://unfccc.int/resource/docs/convkp/conveng.pdf); Supplementary

Fig. 5) and the accounting for changes in carbon stock by afforestation,

reforestation and deforestations is mandatory (Article 3.3), operating

from a base line of 1990. Leaving forests intact was not perceived as an

anthropogenic activity. In addition, the potential consequences of

excluding old-growth forests from national carbon budgets and from

the Kyoto Protocol were downplayed in the carbon-neutrality hypo-

thesis

. However, over 30% (1.3 310

ha) of the global forest area is

classified

by the Food and Agriculture Organization of the United

Nations as primary forest, and this area contains the world’s remaining

old-growth forests. Half (0.6 310

ha) of the primary forests are located

in the boreal and temperate regions of the Northern Hemisphere. On the

basis of our analysis, we expect that these forests alone sequester at least

1.3 60.5 GtC yr

. Hence, 15% of the global forest surface, which is

currently not being considered for offsetting increasing atmospheric

concentrations, is responsible for at least 10% of the global NEP

Sporadic disturbances will interrupt carbon accumulation, implying

that net biome productivity

will be lower, but it will remain positive

as demonstrated by the accumulation of carbon in soils

4,26

,coarsewoody

debris and charcoal

27,28

The present paper shows that old-growth forests are usually carbon

sinks. Because old-growth forests steadily accumulate carbon for cen-

turies, they contain vast quantities of it. They will lose much of this

carbon to the atmosphere if they are disturbed, so carbon-accounting

rules for forests should give credit for leaving old-growth forest intact.

METHODS SUMMARY

We conducted a literature and database searchto determine the fate of the carbon

sequesteredin forests. Observation-based estimates werecompiled for carbon-cycle

components, including biometry-based NPP, eddy-covariance or biometry-based

NEP and chamber-based heterotrophic respiration

. The data set was extended

with site information related to stand characteristics, standing biomass and stand

age. In general, uncertainties in flux estimates were not reported in the literature.

Therefore, weestimatedthe total uncertaintyfor every component fluxcontainedin

the data set using a consistent framework based on expert judgment

(Supplementary Information,section 1.2).The uncertainty framework in ourdata-

base was designed to account for differences in data quality between sites due to

length of time series, methodology and conceptual difficulties (that is, gap filling

and dark respiration). Also, an uncertainty of 20% was assigned to the biomass, age

and density estimates. These uncertainties were propagated through the statistical

analyses by meansof random realizationsbased on Monte Carlo principles.Within

each of the 1,000 random realizations, normally distributed random errors, based

on the uncertainty framework of our database, were added to the observed fluxes.

Therefore, all results that are based on flux data are reported as the weighted mean

and the 95% confidence interval of the probability distribution.

Despite the climatic, edaphic and biological diversity of our observations,

above-ground biomass was observed to be related to stand density in the way

described by self-thinning theory

. Although, this theory was initially developed

for even-aged single-species plant communities, we applied it to our data

(Supplementary Information, section 1.3) to determine the components of the

flux-computed NEP, specifically the above-ground biomass, woody debris and

soil sequestration. Furthermore, self-thinning theory was used to calculate the

theoretical ratio of heterotrophic respiration to NPP and compare it with the

observed ratio in support of the hypothesis that biomass accumulation and

decline are largely driven by stand structure.

Received 18 January; accepted 7 July 2008.

1. Carey, E. V., Sala, A., Keane, R. & Callaway, R. M. Are old forests underestimated

as global carbon sinks? Glob. Change Biol. 7, 339

–

344 (2001).

2. Pregitzer, K. S. & Euskirchen, E. S. Carbon cycling and storage in world forests:

biome patterns related to forest age. Glob. Change Biol. 10, 2052

–

2077 (2004).

3. Magnani, F. et al. The human footprint in the carbon cycle of temperate and boreal

forests. Nature 447, 848

–

850 (2007).

4. Zhou, G. Y. et al. Old-growth forests can accumulate carbon in soils. Science 314,

1417 (2006).

5. Kira, T. & Sihdei, T. Primary production and turnover of organic matter in different

forest ecosystems of the western pacific. Jpn. J. Ecol. 17, 70

–

87 (1967).

6. Odum, E. P. The strategy of ecosystem development. Science 164, 262

–

270

(1969).

7. FAO. Global Forest Resources Assessment 2005. Progress towards sustainable forest

management. Forestry Paper 147 (Food and Agriculture Organization of the

United Nations, 2006).

8. Bolin, B. et al. in IPCC, Land Use, Land-Use Change, and Forestry. A Special Report of

the IPCC (eds Watson, R. T. et al.)23

–

51 (Cambridge Univ. Press, 2000).

9. Fontaine, S. et al. Stability of organic carbon in deep soil layers controlled by fresh

carbon supply. Nature 450, 277

–

280 (2007).

10. Acker, S. A., Halpern, C. B., Harmon, M. E. & Dyrness, C. T. Trends in bole biomass

accumulation, net primary production and tree mortality in Pseudotsuga menziesii

forests of contrasting age. Tree Physiol. 22, 213

–

217 (2002).

11. Knohl, A., Schulze, E. D., Kolle, O. & Buchmann, N. Large carbon uptake by an

unmanaged 250-year-old deciduous forest in Central Germany. Agric. For.

Meteorol. 118, 151

–

167 (2003).

12. Law, B. E. et al. Changes in carbon storage and fluxes in a chronosequence of

ponderosa pine. Glob. Change Biol. 9, 510

–

524 (2003).

13. Desai, A. R. et al. Comparing net ecosystem exchange of carbon dioxide between

an old-growth and mature forest in the upper Midwest, USA. Agric. For. Meteorol.

128, 33

–

55 (2005).

14. Gower, S. T., McMurtrie, R. E. & Murty, D. Aboveground net primary production

decline with stand age: Potential causes. Trends Ecol. Evol. 11, 378

–

382 (1996).

15. Binkley, D. et al. Age-related decline in forest ecosystem growth: an individual-

tree, stand-structure hypothesis. Ecosystems 5, 58

–

67 (2002).

16. Van Tuyl, S., Law, B. E., Turner, D. P. & Gitelman, A. I. Variability in net primary

production and carbon storage in biomass across Oregon forests—an

assessment integrating data from forest inventories, intensive sites, and remote

sensing. For. Ecol. Manage. 209, 273

–

291 (2005).

17. Harmon, M. E., Ferrell, W. K. & Franklin, J. F. Effects on carbon storage of

conversion of old-growth forests to young forests. Science 247, 699

–

702 (1990).

18. Janish, J. E. & Harmon, M. E. Successional changes in live and dead wood carbon

stores: implications for net ecosystem productivity. Tree Physiol. 22, 77

–

(2002).

19. Wirth, C., Czimczik, C. I. & Schulze, E. D. Beyond annual budgets: carbon flux at

different temporal scales in fire-prone Siberian Scots pine forests. Tellus 54,

611

–

630 (2002).

20. Knohl, A. et al. Carbon dioxide exchange of a Russian boreal forest after

disturbance by wind throw. Glob. Change Biol. 8, 231

–

246 (2002).

21. Kowalski, A. S. et al. Paired comparisons of carbon exchange between undisturbed

and regenerating stands in four managed forests in Europe. Glob. Change Biol. 10,

1707

–

1723 (2004).

22. Irvine, J., Law, B. E. & Hibbard, K. A. Postfire carbon pools and fluxes in semiarid

ponderosa pine in Central Oregon. Glob. Change Biol. 13, 1748

–

1760 (2007).

23. Yoda,K., Kira, T., Ogawa, H. & Hozumi,K. Self-thinning in overcrowded pure stands

under cultivated and natural conditions.J. Biol. Osaka City Univ. 14, 107

–

132 (1963).

24. Mladenoff, D. J., White, M. A., Pastor, J. & Crow, T. R. Comparing spatial pattern in

unaltered old-growth and disturbed forest landscapes. Ecol.Appl. 3, 294

–

306 (1993).

25. Chapin, F. S. et al. Reconciling carbon-cycle concepts, terminology and

methodology. Ecosystems 9, 1041

–

1050 (2005).

26. Ciais, P. et al. in The Carbon Balance of Forest Biomes (eds Griffith, H. & Jarvis, P.)

109

–

150 (Taylor and Francis, 2005).

27. Jomura,M. et al. The carbon budget of coarse woody debris in a temperate broad-

leaved secondary forest in Japan. Tellus B 59, 211

–

222 (2007).

28. Preston, C. M. & Schmidt, M. W. I. Black (pyrogenic) carbon: a synthesis of

current knowledge and uncertainties with special consideration of boreal regions.

Biogeosciences 3, 397

–

420 (2006).

29. Luyssaert, S. et al. CO

-balance of boreal, temperate and tropical forest derived

from a global database. Glob. Change Biol. 13, 2509

–

2537 (2007).

Supplementary Information is linked to the online version of the paper at

www.nature.com/nature.

Acknowledgements We thank all site investigators, their funding agencies and the

various regional flux networks (Afriflux, AmeriFlux, AsiaFlux, CarboAfrica,

CarboEuropeIP, ChinaFlux, Fluxnet-Canada, KoFlux, LBA, NECC, OzFlux,

TCOS-Siberia and USCCC), and the Fluxnet project, whose support was essential for

obtaining our measurements. S.L. was supported by CoE ECO UA-Methusalem and

the Research Foundation - Flanders (FWO-Vlaanderen) with a post-doctoral

fellowship and a research grant. A.K. was supported by the European Union with a

Marie Curie fellowship, and B.E.L. was supported by the regional North American

Carbon Program project ORCA (US Department of Energy, Terrestrial Carbon

Program, award number DE-FG02-04ER63917). E.-D.S. was supported by

DFG-Exploratories. Additional funding for this study was received from

CarboEuropeIP (project number GOCE-CT-2003-505572) and Ameriflux.

Author Contributions S.L., B.E.L., A.K. and P.C. compiled the data set. S.L., A.B. and

D.H wrote code and analysed the data. S.L., E.-D.S., A.K., B.E.L., P.C. and J.G.

designed the analyses and wrote the manuscript.

Author Information Reprints and permissions information is available at

www.nature.com/reprints. Correspondence and requests for materials should be

addressed to S.L. (sebastiaan.luyssaert@ua.ac.be).

NATURE

Vol 455

11 September 2008 LETTERS

215

Aboveground live tree carbon stock and change in forests of conterminous United States: influence of stand age

Article

Full-text available

Apr 2023
Carbon Bal Manag

Background Sequestration of carbon on forest land is a common and practical component within many climate action plans developed by state or municipal governments. Initial planning often identifies the general magnitude of sequestration expected given the scope of the project. Because age plays a key role in forest carbon dynamics, we summarize both the carbon stock and accumulation rates in live trees by age class and region, allowing managers and policymakers to assess the influence of forest age class structure on forest carbon storage as represented in current inventories. State-level information is provided in supplementary tables. Results Average regional aboveground live tree carbon stocks (represented on a per area basis) range from 11.6 tC/ha in the Great Plains to 130 tC/ha in the Pacific Northwest West (west-side of Cascades) and increase with age in all regions, although in three regions carbon stock declined in the oldest age class. Regional average annual net change in live aboveground tree carbon varies from a low of − 0.18 tC /ha/yr in the Rocky Mountain South region to a high value of 1.74 tC/ha/yr in Pacific Northwest West. In all regions except Rocky Mountain South, accumulation rates are highest in the younger age classes and decline with age, with older age classes in several western regions showing negative rates. In the Southeast and Pacific Northwest West, intermediate age classes exhibit lower rates, likely due to harvesting activity. Conclusions Aboveground live tree carbon stocks increase and rates of average change decrease with age with few exceptions; this pattern holds when examining hardwood and softwood types individually. Because multiple forest management objectives are often considered and tradeoffs need to be assessed, we recommend considering both measures—standing stock and average annual change—of carbon storage. The relative importance of each component depends on management and policy objectives and the time frame related to those objectives. Harvesting and natural disturbance also affect forest carbon stock and change and may need to be considered if developing projections of potential carbon storage. We present forest carbon summaries at a scale and scope to meet information needs of managers and policymakers.

How to measure the efficiency of bioenergy crops compared to forestation

Article

Full-text available

Nov 2024
BG

The climate mitigation potential of terrestrial carbon dioxide removal (tCDR) methods depends critically on the timing and magnitude of their implementation. In our study, we introduce different measures of efficiency to evaluate the carbon removal potential of afforestation and reforestation (AR) and bioenergy with carbon capture and storage (BECCS) under the low-emission scenario SSP1-2.6 and in the same area. We define efficiency as the potential to sequester carbon in the biosphere in a specific area or store carbon in geological reservoirs or woody products within a certain time. In addition to carbon capture and storage (CCS), we consider the effects of fossil fuel substitution (FFS) through the usage of bioenergy for energy production, which increases the efficiency through avoided CO2 emissions. These efficiency measures reflect perspectives regarding climate mitigation, carbon sequestration, land availability, spatiotemporal dynamics, and the technological progress in FFS and CCS. We use the land component JSBACH3.2 of the Max Planck Institute Earth System Model (MPI-ESM) to calculate the carbon sequestration potential in the biosphere using an updated representation of second-generation bioenergy plants such as Miscanthus. Our spatially explicit modeling results reveal that, depending on FFS and CCS levels, BECCS sequesters 24–158 GtC by 2100, whereas AR methods sequester around 53 GtC on a global scale, with BECCS having an advantage in the long term. For our specific setup, BECCS has a higher potential in the South American grasslands and southeast Africa, whereas AR methods are more suitable in southeast China. Our results reveal that the efficiency of BECCS to sequester carbon compared to “nature-based solutions” like AR will depend critically on the upscaling of CCS facilities, replacing fossil fuels with bioenergy in the future, the time frame, and the location of tCDR deployment.

Carbon Stock Estimation of Compensatory Afforestation Plantation Work in Balod District of Chhattisgarh, India

Article

Full-text available

Aug 2024

This paper encapsulates the findings of carbon stock assessment of compensatory afforestation work done in Balod District of Chhattisgarh. Under the State CAMPA (Compensatory Afforestation Fund Management and Planning Authority) scheme, the afforestation project aims to enhance the local environment, create employment opportunities for the villagers of Armarikala, and provide fodder for nearby farmers' cattle. This initiative not only address the ecological impact of the power transmission line construction but also align with sustainable development goals by providing socio-economic benefits to the local community. The study aimed to quantify the biomass and carbon sequestration potential of diverse tree species in the Compensatory Afforestation Plantation Work in Balod District of Chhattisgarh. The carbon stock data highlights the significance of different tree species, with Terminalia arjuna emerging as a major contributor, sequestering 3,814.2 kg followed by Dalbergia sissoo with 2616.7 kg of carbon in the surveyed area. The carbon stock assessment in Balod District of Chhattisgarh demonstrates the significant ecological and socio-economic benefits of the compensatory afforestation project under the State CAMPA scheme. The findings underscore the project's alignment with sustainable development goals, enhancing both environmental health and local livelihoods.

Investigation of the woody vegetation spectra dependence on the measurement conditions

Conference Paper

Full-text available

Oct 2023

Influence of the river flow pulse on the maturity, resilience, and sustainability of tropical coastal ecosystems

Article

Jan 2023
MAR ENVIRON RES

Coastal marine ecosystems have structural and functional features usually connected by the seasonal transfer of nutrients and organisms. These environments can utilize inter-ecosystem subsidies to increase resilience and maturity and support human activities like fishing. However, the importance of the connection and the role of the seasonal pulse of energy flows to enhance maturity are still poorly understood and reported. Our objective in this paper is to assess the effect of seasonal hydrological pulses on two tropical coastal interconnected ecosystems. Thus, we made four Ecopath models for estuarine and neritic environments considering the dry and rainy seasons, with a similar sampling design that allowed them to be compared. Our results provide evidence for the occurrence of the pulsed ecosystems since both environments seem driven by the river flow. Estuary presents more and more substantial differences (measured by ecosystem attributes) in both seasons because it is directly affected by river floods than the neritic environment. The neritic is affected indirectly by the movement of species from the estuary and by a weaker river flow. In the dry season, the differences between ecosystems are lower because the dry season trend to homogenize cycling, maturity, homeostasis, and resilience. We found that the seasonal river flow (pulse) forces the variability of biomass, flows, and ecosystem features, and this variance creates the required stability for both ecosystems. Still, these environments benefit through the exchange of components that relieve the pressures of predation on specific groups and maintain the energy flow necessary for the functioning of their trophic webs. The pulse by the rainfall favors connectivity and equalizes the two systems, increasing the connectivity between them and the exchange of subsidies that strengthens the trophic structures, contributing to the increase in maturity. In these ecosystems, seasonal changes become a key factor for exchanging flows that will promote sustainability, the accumulation of more biomass (growth), and the optimization of reserve energy (development) in both systems. This efficient joint strategy of perpetuation is what promotes resistance and resilience to these ecosystems, which together can reach different states of equilibrium, translated into maturity to withstand new environmental changes.

Accounting for forest management in the estimation of forest carbon balance using the dynamic vegetation model LPJ-GUESS (v4.0, r9710): implementation and evaluation of simulations for Europe

Article

Full-text available

Oct 2021
GMD

Global forests are the main component of the land carbon sink, which acts as a partial buffer to CO2 emissions into the atmosphere. Dynamic vegetation models offer an approach to projecting the development of forest carbon sink capacity in a future climate. Forest management capabilities are important to include in dynamic vegetation models to account for the effects of age and species structure and wood harvest on carbon stocks and carbon storage potential. This article describes the implementation of a forest management module containing even-age and clear-cut and uneven-age and continuous-cover management alternatives in the dynamic vegetation model LPJ-GUESS. Different age and species structure initialisation strategies and harvest alternatives are introduced. The model is applied at stand and European scales. Different management alternatives are applied in simulations of European beech (Fagus sylvaticus) and Norway spruce (Picea abies) even-aged monoculture stands in central Europe and evaluated against above-ground standing stem volume and harvested volume data from long-term experimental plots. At the European scale, an automated thinning and clear-cut strategy is applied. Modelled carbon stocks and fluxes are evaluated against reported data at the continent and country levels. Including wood harvest in regrowth forests increases the simulated total European carbon sink by 32 % in 1991–2015 and improves the fit to the reported European carbon sink, growing stock, and net annual increment (NAI). Growing stock (156 m3 ha-1) and NAI (5.4 m3 ha1 yr1) densities in 2010 are close to reported values, while the carbon sink density in 2000–2007 (0.085 kg C m-2 yr1) equates to 63 % of reported values, most likely reflecting uncertainties in carbon fluxes from soil given the unaccounted for forest land-use history in the simulations. The fit of modelled and reported values for individual European countries varies, but NAI is generally closer to reported values when including wood harvest in simulations.

Increased microbial carbon use efficiency and turnover rate drive soil organic carbon storage in old-aged forest on the southeastern Tibetan Plateau

Article

Full-text available

Oct 2024
BIOL FERT SOILS

It is widely accepted that old-aged forest can accumulate soil organic carbon (SOC). How microbial physiological traits respond to forest age and whether they drive SOC sequestration in old-aged forest remain elusive. Therefore, we compared the microbial C use efficiency (CUE), biomass turnover rate (rB), microbial biomass C (MBC) and necromass C (MNC) across soil profiles from middle and old-aged forest and evaluated how these microbial traits are related to SOC storage. The results revealed that both forests could accumulate SOC and old-aged forest supported higher SOC storage than middle-aged forest from 2005 to 2020. Moreover, SOC was concentrated on the surface soils of middle-aged forest, whereas it was more distributed across the deeper soil profile in old-aged forest. Compared with middle-aged forest, the O, A and B soil layers of old-aged forest presented increases in microbial CUE (17.8%, 36.9% and 25.0%, respectively), rB (43.7%, 39.7% and 10.8%, respectively), MBC (114.8%, 81.1% and 122.9%, respectively), and MNC content (47.0%, 22.2% and 21.6%, respectively). Random forest analysis suggested that SOC accumulation is controlled mainly by microbial physiological traits rather than other factors including environmental variables. Specifically, microbial CUE and turnover rates increased in old-aged forest, resulting in higher MBC and MNC contents, which in turn led to SOC accumulation. Moreover, the effects of plant and soil properties on SOC storage are regulated mainly by microbial-physiological parameters and the size of microbial C pools. Our findings provide valuable insights into the microbial mechanisms underlying SOC storage in old-aged forest.

Emissionsreduktionen durch ökosystembasierte Ansätze

Chapter

Full-text available

Dec 2023

Ökosystembasierte Klimapolitik beinhaltet Änderungen der bestehenden Landnutzung. Emissionen aus der Landwirtschaft und aus der Trockenlegung kohlenstoffreicher Böden machen rund ein Achtel der Treibhausgasemissionen Deutschlands aus. Wälder und deren Holzprodukte hingegen entlasteten die Atmosphäre von Treibhausgasemissionen. Moorwiedervernässung, Aufforstungen, geänderte Viehhaltung und andere Maßnahmen besitzen hohe Emissionsminderungspotenziale. Ihre Wechselwirkungen mit anderen Landnutzungsmaßnahmen und die Auswirkungen auf andere Sektoren können aber zu Ver- lagerungseffekten, wie Güterimporte und damit Emissionsexporte, und zu Mehremissionen führen. Die aktuellen Klimaschutzziele machen daher umfangreiche Maßnahmen und eine Transformation der Landnutzung (Sektor LULUCF) notwendig, Maßnahmenvorschläge und Politiken dürfen jedoch nie isoliert betrachtet werden und Wechselwirkungen innerhalb des Sektors und mit anderen Sektoren sind zu berücksichtigen.

The role of socialisation of the forest management system in Poland in the face of the need to mitigate climate change

Article

Full-text available

Dec 2022

Climate change will have a significant impact on forests as most of the factors determining their condition are modified by the effects of the climate change process. Some of these effects are a change in the distribution and amount of precipitation, an increase in the frequency of extreme meteorological phenomena, including hurricane winds, temperature distribution, or a change in the length of the growing season. In order to maintain the productivity of Polish forests and the range of ecosystem services they provide, the forestry sector will have to adapt to these changes. However, forestry will also have to take a part in holding back climate change. Achieving climate neutrality by mid-21st century and ensuring a 55% reduction in greenhouse gas emissions by 2030 will not be possible without using the ability of forests to absorb and permanently store carbon. Polish forestry seems to be insufficiently prepared for the challenges ahead. A new national forestry policy has not been developed in the past twenty years, which results, inter alia, in a lack of any clear indication of the role of Polish forests in climate protection. Adaptation to the effects of climate change is hampered by the lack of up-to-date, detailed scenarios of how this process will affect the climate factors in Poland. Particularly dangerous, in light of the role of forests in climate protection, is a significant decrease in the afforested area, which in turn leads to a reduction in the amount of carbon absorbed by them. Another obstacle to implementation of effective measures may be the growing disparity between the current forestry practice and social expectations, as well as a low degree of willingness from the State Forests to cooperate with stakeholders who present different opinions on how to conduct forest management. This obstacle may lead to disputes about the management of Polish forests at the European Union level and rulings of the Court of Justice of the European Union. The conducted analyses showed that cooperation with a wide range of stakeholders will be the basic condition for the inclusion of Polish forests in the implementation of climate policy objectives on a greater scale. It should help define the role of this sector in this process, implement the necessary adaptative and climate protection measures, and support activities aimed at acquiring new land for afforestation.

Малонарушенные лесные территории мира: концепция, методика выделения, результаты многолетнего мониторинга

Conference Paper

Full-text available

Apr 2016

Стр. 17-21 Малонарушеные лесные территории (МЛТ) – последние сохранившиеся крупные лесные массивы, не преобразованные деятельностью человека. В 2014 г. проанализировано сокращение МЛТ за 2000-2013 годы. Около 20% всех лесов мира являются малонарушенными. Площадь МЛТ в мире сократилась на 7,2%. Основной причиной деградации МЛТ является фрагментация лесных массивов, и лишь в 14% случаев - непосредственное сокращение лесного покрова.

Comparing Spatial Pattern in Unaltered Old-Growth and Disturbed Forest Landscapes

Article

Full-text available

May 1993

Used geographic information systems to analyze the structure of a second-growth forest landscape (9600 ha) in Michigan and Wisconsin, that contains scattered old-growth patches, and compared this landscape to a nearby, unaltered old-growth landscape on comparable landforms and soils to assess the effects of human activity on forest spatial pattern. The natural old-growth landscape is dominated by the original forest cover of eastern hemlock Tsuga canadensis, sugar maple Acer saccharum and yellow birch Betula alleghaniensis. The disturbed landscape has only scattered, remnant patches of old-growth ecosystems among a greater number of early successional hardwood and conifer forest types. The disturbed landscape has significantly more small forest patches and fewer large, matrix patches than the intact landscape. Forest patches in the fragmented landscape are significantly simpler in shape (lower fractal dimension, D) than in the intact old-growth landscape. Change in fractal dimension with patch size, a relationship that may be characteristics of differing processes of patch formation at different scales, is present within the intact landscape but has been obscured by human activity in the disturbed landscape. Important ecosystem juxtapositions of the old-growth landscape, such as hemlock with lowland conifers, have been lost in the disturbed landscape. Significant landscape heterogeneity in this glaciated region is produced by landforms alone, without natural or human disturbances. -from Authors

The human footprint in the carbon cycle of temperate and boreal forests

Article

Full-text available

Jun 2007

Temperate and boreal forests in the Northern Hemisphere cover an area of about 2 × 107 square kilometres and act as a substantial carbon sink (0.6-0.7 petagrams of carbon per year). Although forest expansion following agricultural abandonment is certainly responsible for an important fraction of this carbon sink activity, the additional effects on the carbon balance of established forests of increased atmospheric carbon dioxide, increasing temperatures, changes in management practices and nitrogen deposition are difficult to disentangle, despite an extensive network of measurement stations. The relevance of this measurement effort has also been questioned, because spot measurements fail to take into account the role of disturbances, either natural (fire, pests, windstorms) or anthropogenic (forest harvesting). Here we show that the temporal dynamics following stand-replacing disturbances do indeed account for a very large fraction of the overall variability in forest carbon sequestration. After the confounding effects of disturbance have been factored out, however, forest net carbon sequestration is found to be overwhelmingly driven by nitrogen deposition, largely the result of anthropogenic activities. The effect is always positive over the range of nitrogen deposition covered by currently available data sets, casting doubts on the risk of widespread ecosystem nitrogen saturation under natural conditions. The results demonstrate that mankind is ultimately controlling the carbon balance of temperate and boreal forests, either directly (through forest management) or indirectly (through nitrogen deposition).

Beyond annual budgets: carbon flux at different temporal scales in fire-prone Siberian Scots pine forests

Article

Nov 2002

Primary production and turnover of organic matter in different forest ecosystems of the Western Paci

Article

Apr 1967

This review is intended to introduce an outline of the results of community metabolism studies on various forest ecosystems of the Western Pacific area made by Japanese investigators in these past ten years. In 1955,SATOO opened this line of research by publishing his first report(65)on the productivity of artificial plantations in this country. A few years later, in 1957 and 1958,four groups of ecologists and forest scientists including ourselves began almost simultaneously to follow him, and the fields of study were expanded to include various types of natural and artificial vegetation ranging from subarctic conifer forests of Hokkaido to the tropical jungle of Southeast Asia. Since that time, more than one hundred stands belonging to some forty different forest types have been investigated, of course mostly within Japan Proper, but also in the Ryukyus(40), Thailand(21,22,24,42,44-47,93,100)and Cambodia(23). Steady progress has been made in the methodology for analysing the metabolism of forest community. These studies were, therefore, not always based on one and the same method, making it difficult to compare the results obtained by different authors. Thus the contents of this review are more or less tentative ; yet we hope, this may well be a useful starting point for more advanced studies to be made under the framework of the International Biological Programme.

FAO. 2005. Global Forest Resources Assessment 2005: progress Towards Sustainable Forest Management. FAO, Rome, IT

Book

Jan 2005

Self-Thinning in Overcrowded Pure Stands Under Cultivated and Natural Conditions

Article

Jan 1963

Changes in carbon storage and fluxes in a chronosequence of ponderosa pine

Article

Apr 2003
GLOBAL CHANGE BIOL

Forest development following stand-replacing disturbance influences a variety of ecosystem processes including carbon exchange with the atmosphere. On a series of ponderosa pine (Pinius ponderosa var. Laws.) stands ranging from 9 to> 300 years in central Oregon, USA, we used biological measurements to estimate carbon storage in vegetation and soil pools, net primary productivity (NPP) and net ecosystem productivity (NEP) to examine variation with stand age. Measurements were made on plots representing four age classes with three replications: initiation (I, 9–23 years), young (Y, 56–89 years), mature (M, 95–106 years), and old (O, 190–316 years) stands typical of the forest type in the region. Net ecosystem productivity was lowest in the I stands (−124 g C m−2 yr−1), moderate in Y stands (118 g C m−2 yr−1), highest in M stands (170 g C m−2 yr−1), and low in the O stands (35 g C m−2 yr−1). Net primary productivity followed similar trends, but did not decline as much in the O stands. The ratio of fine root to foliage carbon was highest in the I stands, which is likely necessary for establishment in the semiarid environment, where forests are subject to drought during the growing season (300–800 mm precipitation per year). Carbon storage in live mass was the highest in the O stands (mean 17.6 kg C m−2). Total ecosystem carbon storage and the fraction of ecosystem carbon in aboveground wood mass increased rapidly until 150–200 years, and did not decline in older stands. Forest inventory data on 950 ponderosa pine plots in Oregon show that the greatest proportion of plots exist in stands ∼ 100 years old, indicating that a majority of stands are approaching maximum carbon storage and net carbon uptake. Our data suggests that NEP averages ∼ 70 g C m−2 year−1 for ponderosa pine forests in Oregon. About 85% of the total carbon storage in biomass on the survey plots exists in stands greater than 100 years, which has implications for managing forests for carbon sequestration. To investigate variation in carbon storage and fluxes with disturbance, simulation with process models requires a dynamic parameterization for biomass allocation that depends on stand age, and should include a representation of competition between multiple plant functional types for space, water, and nutrients.

The carbon budget of coarse woody debris in a temperate broad‐leaved secondary forest in Japan

Article

Feb 2007
TELLUS B

We evaluated the carbon budget of coarse woody debris (CWD) in a temperate broad-leaved secondary forest. On the basis of a field survey conducted in 2003, the mass of CWD was estimated at 9.30 tC ha−1, with snags amounting to 60% of the total mass. Mean annual CWD input mass was estimated to be 0.61 tC ha−1 yr−1 by monitoring tree mortality in the forest from 1999 to 2004. We evaluated the CWD decomposition rate as the CO2 evolution rate from CWD by measuring CO2 emissions from 91 CWD samples (RCWD) with a closed dynamic chamber and infrared gas analysis system. The relationships between RCWD and temperature in the chamber, water content of the CWD, and other CWD characteristics were determined. By scaling the measured RCWD to the ecosystem, we estimated that the annual RCWD in the forest in 2003 was 0.50 tC ha−1 yr−1 or 10%–16% of the total heterotrophic respiration. Therefore, 0.11 tC ha−1 yr−1 or 7% of the forest net ecosystem production was sequestered by CWD. In a young forest, in which CWD input and decomposition are not balanced, the CWD carbon budget needs to be quantified for accurate evaluation of the forest carbon cycle and NEP.

Postfire carbon pools and fluxes in semiarid ponderosa pine in Central Oregon

Article

Aug 2007
GLOBAL CHANGE BIOL

Forest fire dramatically affects the carbon storage and underlying mechanisms that control the carbon balance of recovering ecosystems. In western North America where fire extent has increased in recent years, we measured carbon pools and fluxes in moderately and severely burned forest stands 2 years after a fire to determine the controls on net ecosystem productivity (NEP) and make comparisons with unburned stands in the same region. Total ecosystem carbon in soil and live and dead pools in the burned stands was on average 66% that of unburned stands (11.0 and 16.5 kg C m−2, respectively, P<0.01). Soil carbon accounted for 56% and 43% of the carbon pools in burned and unburned stands. NEP was significantly lower in severely burned compared with unburned stands (P<0.01) with an increasing trend from −125±44 g C m−2 yr−1 (±1 SD) in severely burned stands (stand replacing fire), to −38±96 and +50±47 g C m−2 yr−1 in moderately burned and unburned stands, respectively. Fire of moderate severity killed 82% of trees <20 cm in diameter (diameter at 1.3 m height, DBH); however, this size class only contributed 22% of prefire estimates of bole wood production. Larger trees (> 20 cm DBH) suffered only 34% mortality under moderate severity fire and contributed to 91% of postfire bole wood production. Growth rates of trees that survived the fire were comparable with their prefire rates. Net primary production NPP (g C m−2 yr−1, ±1 SD) of severely burned stands was 47% of unburned stands (167±76, 346±148, respectively, P<0.05), with forb and grass aboveground NPP accounting for 74% and 4% of total aboveground NPP, respectively. Based on continuous seasonal measurements of soil respiration in a severely burned stand, in areas kept free of ground vegetation, soil heterotrophic respiration accounted for 56% of total soil CO2 efflux, comparable with the values of 54% and 49% previously reported for two of the unburned forest stands. Estimates of total ecosystem heterotrophic respiration (Rh) were not significantly different between stand types 2 years after fire. The ratio NPP/Rh averaged 0.55, 0.85 and 1.21 in the severely burned, moderately burned and unburned stands, respectively. Annual soil CO2 efflux was linearly related to aboveground net primary productivity (ANPP) with an increase in soil CO2 efflux of 1.48 g C yr−1 for every 1 g increase in ANPP (P<0.01, r2= 0.76). There was no significant difference in this relationship between the recently burned and unburned stands. Contrary to expectations that the magnitude of NEP 2 years postfire would be principally driven by the sudden increase in detrital pools and increased rates of Rh, the data suggest NPP was more important in determining postfire NEP.

Are old forests underestimated as global carbon sinks?

Article

Apr 2001
GLOBAL CHANGE BIOL

Old forests are important carbon pools, but are thought to be insignificant as current atmospheric carbon sinks. This perception is based on the assumption that changes in productivity with age in complex, multiaged, multispecies natural forests can be modelled simply as scaled-up versions of individual trees or even-aged stands. This assumption was tested by measuring the net primary productivity (NPP) of natural subalpine forests in the Northern Rocky Mountains, where NPP is from 50% to 100% higher than predicted by a model of an even-age forest composed of a single species. If process-based terrestrial carbon models underestimate NPP by 50% in just one quarter of the temperate coniferous forests throughout the world, then global NPP is being underestimated by 145 Tg of carbon annually. This is equivalent to 4.3–7.6% of the missing atmospheric carbon sink. These results emphasize the need to account for multiple-aged, species-diverse, mature forests in models of terrestrial carbon dynamics to approximate the global carbon budget.

Old-growth forests as global carbon sinks. Nature

Recommended publications

Last Chance to Apply! 18 Assistant & Associate Professor positions at VU Amsterdam

See our 18 open Asst/Assoc. Professor positions at the science faculty of VU Amsterdam

Com afecta el model actual de gestió forestal els recursos aquàtics del Parc?