Can we set a global threshold age to define mature forests?
Globally, mature forests appear to be increasing in biomass density (BD). There is disagreement whether these increases are the result of increases in atmospheric CO2 concentrations or a legacy effect of previous land-use. Recently, it was suggested that a threshold of 450 years should be used to de...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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PeerJ Inc.
2016-02-01
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| Series: | PeerJ |
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| Online Access: | https://peerj.com/articles/1595.pdf |
| _version_ | 1827606614361767936 |
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| author | Philip Martin Martin Jung Francis Q. Brearley Relena R. Ribbons Emily R. Lines Aerin L. Jacob |
| author_facet | Philip Martin Martin Jung Francis Q. Brearley Relena R. Ribbons Emily R. Lines Aerin L. Jacob |
| author_sort | Philip Martin |
| collection | DOAJ |
| description | Globally, mature forests appear to be increasing in biomass density (BD). There is disagreement whether these increases are the result of increases in atmospheric CO2 concentrations or a legacy effect of previous land-use. Recently, it was suggested that a threshold of 450 years should be used to define mature forests and that many forests increasing in BD may be younger than this. However, the study making these suggestions failed to account for the interactions between forest age and climate. Here we revisit the issue to identify: (1) how climate and forest age control global forest BD and (2) whether we can set a threshold age for mature forests. Using data from previously published studies we modelled the impacts of forest age and climate on BD using linear mixed effects models. We examined the potential biases in the dataset by comparing how representative it was of global mature forests in terms of its distribution, the climate space it occupied, and the ages of the forests used. BD increased with forest age, mean annual temperature and annual precipitation. Importantly, the effect of forest age increased with increasing temperature, but the effect of precipitation decreased with increasing temperatures. The dataset was biased towards northern hemisphere forests in relatively dry, cold climates. The dataset was also clearly biased towards forests <250 years of age. Our analysis suggests that there is not a single threshold age for forest maturity. Since climate interacts with forest age to determine BD, a threshold age at which they reach equilibrium can only be determined locally. We caution against using BD as the only determinant of forest maturity since this ignores forest biodiversity and tree size structure which may take longer to recover. Future research should address the utility and cost-effectiveness of different methods for determining whether forests should be classified as mature. |
| first_indexed | 2024-03-09T06:40:27Z |
| format | Article |
| id | doaj.art-a50ea3e06b7743138eaa0982bb7fd0f1 |
| institution | Directory Open Access Journal |
| issn | 2167-8359 |
| language | English |
| last_indexed | 2024-03-09T06:40:27Z |
| publishDate | 2016-02-01 |
| publisher | PeerJ Inc. |
| record_format | Article |
| series | PeerJ |
| spelling | doaj.art-a50ea3e06b7743138eaa0982bb7fd0f12023-12-03T10:51:44ZengPeerJ Inc.PeerJ2167-83592016-02-014e159510.7717/peerj.1595Can we set a global threshold age to define mature forests?Philip Martin0Martin Jung1Francis Q. Brearley2Relena R. Ribbons3Emily R. Lines4Aerin L. Jacob5Centre for Conservation Ecology and Environmental Science, Bournemouth University, Bournemouth, United KingdomSchool of Life Science, University of Sussex, Brighton, United KingdomSchool of Science and the Environment, Manchester Metropolitan University, Manchester, United KingdomSchool of Environment, Natural Resources and Geography, Bangor University, Bangor, United KingdomSchool of Geography, Queen Mary University of London, London, United KingdomSchool of Environmental Studies, University of Victoria, Victoria, CanadaGlobally, mature forests appear to be increasing in biomass density (BD). There is disagreement whether these increases are the result of increases in atmospheric CO2 concentrations or a legacy effect of previous land-use. Recently, it was suggested that a threshold of 450 years should be used to define mature forests and that many forests increasing in BD may be younger than this. However, the study making these suggestions failed to account for the interactions between forest age and climate. Here we revisit the issue to identify: (1) how climate and forest age control global forest BD and (2) whether we can set a threshold age for mature forests. Using data from previously published studies we modelled the impacts of forest age and climate on BD using linear mixed effects models. We examined the potential biases in the dataset by comparing how representative it was of global mature forests in terms of its distribution, the climate space it occupied, and the ages of the forests used. BD increased with forest age, mean annual temperature and annual precipitation. Importantly, the effect of forest age increased with increasing temperature, but the effect of precipitation decreased with increasing temperatures. The dataset was biased towards northern hemisphere forests in relatively dry, cold climates. The dataset was also clearly biased towards forests <250 years of age. Our analysis suggests that there is not a single threshold age for forest maturity. Since climate interacts with forest age to determine BD, a threshold age at which they reach equilibrium can only be determined locally. We caution against using BD as the only determinant of forest maturity since this ignores forest biodiversity and tree size structure which may take longer to recover. Future research should address the utility and cost-effectiveness of different methods for determining whether forests should be classified as mature.https://peerj.com/articles/1595.pdfBiomassForestSuccessionClimateMature forestCarbon |
| spellingShingle | Philip Martin Martin Jung Francis Q. Brearley Relena R. Ribbons Emily R. Lines Aerin L. Jacob Can we set a global threshold age to define mature forests? PeerJ Biomass Forest Succession Climate Mature forest Carbon |
| title | Can we set a global threshold age to define mature forests? |
| title_full | Can we set a global threshold age to define mature forests? |
| title_fullStr | Can we set a global threshold age to define mature forests? |
| title_full_unstemmed | Can we set a global threshold age to define mature forests? |
| title_short | Can we set a global threshold age to define mature forests? |
| title_sort | can we set a global threshold age to define mature forests |
| topic | Biomass Forest Succession Climate Mature forest Carbon |
| url | https://peerj.com/articles/1595.pdf |
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