HETEROFOR 1.0: a spatially explicit model for exploring the response of structurally complex forests to uncertain future conditions – Part 1: Carbon fluxes and tree dimensional growth
<p>Given the multiple abiotic and biotic stressors resulting from global changes, management systems and practices must be adapted in order to maintain and reinforce the resilience of forests. Among others, the transformation of monocultures into uneven-aged and mixed stands is an avenue to im...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2020-03-01
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| Series: | Geoscientific Model Development |
| Online Access: | https://www.geosci-model-dev.net/13/905/2020/gmd-13-905-2020.pdf |
| Summary: | <p>Given the multiple abiotic and biotic stressors resulting from global
changes, management systems and practices must be adapted in order to
maintain and reinforce the resilience of forests. Among others, the
transformation of monocultures into uneven-aged and mixed stands is an
avenue to improve forest resilience. To explore the forest response to these new silvicultural practices under a changing environment, one needs models combining a process-based approach with a detailed spatial representation, which is quite rare.</p>
<p>We therefore decided to develop our own model (HETEROFOR for HETEROgeneous
FORest) according to a spatially explicit approach, describing individual
tree growth based on resource sharing (light, water and nutrients).
HETEROFOR was progressively elaborated within Capsis (Computer-Aided
Projection for Strategies in Silviculture), a collaborative modelling
platform devoted to tree growth and stand dynamics.</p>
<p>This paper describes the carbon-related processes of HETEROFOR
(photosynthesis, respiration, carbon allocation and tree dimensional growth) and evaluates the model performances for three broadleaved stands with different species compositions (Wallonia, Belgium). This first evaluation
showed that HETEROFOR predicts well individual radial growth (Pearson's
correlation of 0.83 and 0.63 for the European beech and sessile oak,
respectively) and is able to reproduce size–growth relationships. We also
noticed that the net to gross primary production (npp to gpp) ratio option for describing maintenance
respiration provides better results than the temperature-dependent routine,
while the process-based (Farquhar model) and empirical (radiation use
efficiency) approaches perform similarly for photosynthesis. To illustrate
how the model can be used to predict climate change impacts on forest
ecosystems, we simulated the growth dynamics of the mixed stand driven by
three IPCC climate scenarios. According to these simulations, the tree growth trends will be governed by the <span class="inline-formula">CO<sub>2</sub></span> fertilization effect, with the increase in vegetation period length and the increase in water stress also playing a role but offsetting each other.</p> |
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| ISSN: | 1991-959X 1991-9603 |