Estimating spatial variation in the effects of climate change on the net primary production of Japanese cedar plantations based on modeled carbon dynamics

Abstract

Spatiotemporal prediction of the response of planted forests to a changing climate is increasingly important for the sustainable management of forest ecosystems. In this study, we present a methodology for estimating spatially varying productivity in a planted forest and changes in productivity with a changing climate in Japan, with a focus on Japanese cedar (Cryptomeria japonica D. Don) as a representative tree species of this region. The process-based model Biome-BGC was parameterized using a plant trait database for Japanese cedar and a Bayesian optimization scheme. To compare productivity under historical (1996–2000) and future (2096–2100) climatic conditions, the climate scenarios of two representative concentration pathways (i.e., RCP2.6 and RCP8.5) were used in five global climate models (GCMs) with approximately 1-km resolution. The seasonality of modeled fluxes, namely gross primary production, ecosystem respiration, net ecosystem exchange, and soil respiration, improved after two steps of parameterization. The estimated net primary production (NPP) of stands aged 36–40 years under the historical climatic conditions of the five GCMs was 0.77 ± 0.10 kgC m-2 year-1 (mean ± standard deviation), in accordance with the geographical distribution of forest NPP estimated in previous studies. Under the RCP2.6 and RCP8.5 scenarios, the mean NPP of the five GCMs increased by 0.04 ± 0.07 and 0.14 ± 0.11 kgC m-2 year-1, respectively. The increases in annual NPP were small in the southwestern region because of the decreases in summer NPP and the small increases in winter NPP under the RCP2.6 and RCP8.5 scenarios, respectively. Under the RCP2.6 scenario, Japanese cedar was at risk in the southwestern region, in accordance with previous studies, and monitoring and silvicultural practices should be modified accordingly.

Water and Temperature Ecophysiological Challenges of Forests Plantations under Climate Change

“…However, productivity gains have been frequently reported due to longer growing seasons, or increases in seasonal temperature, rainfall, and/or atmospheric CO 2 [129][130][131]. Interestingly, the gains in productivity observed in several reports rely on a CO 2 fertilization effect that, when removed, may result in productivity decreases at sites with water and/or nutrient resource limitations or environmental temperature constraints that may elicit unknown results [123,132]. Forest ecosystem responses under elevated CO 2 may be affected by interactions with water and nutrient availability that depend strongly on site-specific characteristics [133].…”

Estimation of the effect of future changes in precipitation in Japan on pluvial flood damage and the damage reduction effect of mitigation/adaptation measures

“…The Regional Climate Projection Dataset NARO2017-v2.7r provides historical data from 1981 to 2005 and future data from 2006 to 2100. This dataset was used in many previous studies on climate change impact assessment in Japan [28,[33][34][35]. Thus, this dataset allows for a comparison of impact assessments.…”

Sensitivity Analysis of Biome-BGCMuSo for Gross and Net Primary Productivity of Typical Forests in China

“…The use of the input parameter values of a specific site can achieve the best simulation and a relatively high degree of acceptance of the sensitivity analysis results (Thornton et al 2002;Toriyama et al 2021).…”