Evaluation of simulated ozone effects in forest ecosystems against biomass damage estimates from fumigation experiments
<p>Regional estimates of the effects of ozone pollution on forest growth depend on the availability of reliable injury functions that estimate a representative ecosystem response to ozone exposure. A number of such injury functions for forest tree species and forest functional types have re...
| Main Authors: | , , , , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-11-01
|
| Series: | Biogeosciences |
| Online Access: | https://www.biogeosciences.net/15/6941/2018/bg-15-6941-2018.pdf |
| Summary: | <p>Regional estimates of the effects of ozone pollution on forest growth depend
on the availability of reliable injury functions that estimate a
representative ecosystem response to ozone exposure. A number of such injury
functions for forest tree species and forest functional types have recently
been published and subsequently applied in terrestrial biosphere models to
estimate regional or global effects of ozone on forest tree productivity and
carbon storage in the living plant biomass. The resulting impacts estimated
by these biosphere models show large uncertainty in the magnitude of ozone
effects predicted. To understand the role that these injury functions play in
determining the variability in estimated ozone impacts, we use the O-CN
biosphere model to provide a standardised modelling framework. We test four
published injury functions describing the leaf-level, photosynthetic response
to ozone exposure (targeting the maximum carboxylation capacity of Rubisco
(<i>V</i><sub>cmax</sub>) or net photosynthesis) in terms of their simulated
whole-tree biomass responses against data from 23 ozone filtration/fumigation
experiments conducted with young trees from European tree species at sites
across Europe with a range of climatic conditions. Our results show that none
of these previously published injury functions lead to simulated whole-tree
biomass reductions in agreement with the observed dose–response relationships
derived from these field experiments and instead lead to significant over-
or underestimations of the ozone effect. By re-parameterising these
photosynthetically based injury functions, we develop linear, plant-functional-type-specific dose–response relationships, which provide accurate simulations
of the observed whole-tree biomass response across these 23 experiments.</p> |
|---|---|
| ISSN: | 1726-4170 1726-4189 |