Initial Physiological Responses of First-year Pinus densiflora and Larix kaempferi Seedlings to Open-field Artificial Warming and Precipitation Manipulation
Abstract
The initial physiological responses are known to influence the survival rate and future growth of the seedlings. This study was conducted to investigate the impacts of rising air temperature and changing amount of precipitation on the physiological responses of Pinus densiflora and Larix kaempferi seedlings. In April 2018, P. densiflora and L. kaempferi seeds were sown separately in each plot, which was composed of three replication sets of six treatments; (temperature control and warming) × (precipitation control, precipitation increase, and precipitation decrease). The warming plots have been heated with infrared lamps to make 3 °C higher air temperature compared with the temperature control plots. Precipitation was blocked with transparent panels in the precipitation decrease plots (-40%), and the blocked precipitation was pumped into precipitation increase plots (+40%). Net photosynthetic rate (Pn), transpiration rate (E), and stomatal conductance (Gs) were measured in June and July 2018 (n=3). Results were different by the species and the treatments. For P. densiflora, Pn, E, and Gs significantly changed due to the warming treatment, however, they were not affected by the precipitation manipulation; Pn, E, and Gs decreased by 4.7%, 20.0%, and 18.0% in June and 11.9%, 30.0%, and 39.0% in July, respectively, under the warming treatment. It seems that the increasing leaf surrounding temperature due to the warming treatment caused a dry condition and stomata closure, which resulted in declines of Pn, E, and Gs for P. densiflora. For L. kaempferi, both warming treatment and precipitation manipulation did not affect Pn, E, and Gs. These results indicate that the initial impacts of the warming treatment differ depending on the species, therefore, further investigation should be done on the species-specific responses to the changes in temperature and precipitation.
*This study was supported by Biodiversity Conservation Fund of Kazakhstan ('Phyto-forest melioration on the dried bottom of Aral Sea').- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.B43M3005A
- Keywords:
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- 0414 Biogeochemical cycles;
- processes;
- and modeling;
- BIOGEOSCIENCESDE: 0476 Plant ecology;
- BIOGEOSCIENCESDE: 0486 Soils/pedology;
- BIOGEOSCIENCESDE: 1630 Impacts of global change;
- GLOBAL CHANGE