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| Titel |
Productivity of Russian forests during recent decades (1960-2010s) |
| VerfasserIn |
Anatoly Shvidenko, Dmitry Schepaschenko, Ian McCallum |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250055992
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| Zusammenfassung |
| Knowledge of long term indicators of forest productivity is very important for reliable
assessment of interaction of forests with major global biogeochemical cycles. We present a
systematic analysis of indicators of productivity of Russian forests (live and dead biomass,
net primary production, net ecosystem production, net ecosystem exchange; net and gross
growth) for the last 50 years (1960-2010) using the diversity of available information sources
and methods (forest inventories; different empirical and semi-empirical models;
eddy-covariance; remote sensing products; dynamic vegetation models). Based on as
comprehensive as possible adherence to the principles of applied systems analysis, we made
an attempt to provide a time series analysis of indicators of forest productivity in Russia
aiming at (1) obtaining the most reliable results, and (2) comprehensively assessing the
variability and biases of the indicators. Practically all methods used resulted in biased
estimates, sometimes significant. Taking into account the fuzzy character of assessment of
forest productivity for large areas, any of the existing methods (used individually) are not able
to recognize structural uncertainties. In order to get the most probable results and
related uncertainties, a special statistical procedure for harmonizing along with
multiple constraints of the estimates obtained by independent methods is suggested.
Application of the above methodology resulted in a rather consistent assessment of the
major indicators of productivity. For instance, we showed that forest live biomass at
the country level could be estimated with uncertainty of 4-6% and net primary
production – 7-10% (confidential interval 0.9) for individual years. These uncertainties
decrease for about one-third in long-period time series. This allows us to observe the
trend of increasing productivity of Russian forests during the last five decades at
levels of 0.5±0.2% year-1. However, the above results should be used with caution
because the entire procedure inevitably includes expert estimates and judgments. |
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