5:15 PM - 6:30 PM
[ACG37-P04] Spatio-temporal variation of soil respiration in coastal sand dunes and the mechanisms
Keywords:Chamber, Drought stress, Zonal distribution, Coastal vegetation, Carbon cycle
Coastal sand dunes are unique ecosystems where zonal distribution of coastal vegetations is typically observed. Globally, costal sand dunes are decreasing the area because of development and climate change. On the other hand, coastal sand dunes are gathering attention as multipurpose green infrastructure for mitigation and adaptation against global climate change. Studies for carbon cycle in coastal sand dunes can contribute to add a new value for the unique ecosystems from the viewpoint of carbon sequestration and sustainable ecosystem management.
Soil respiration (Rs) is one of the largest carbon flux components in terrestrial carbon cycle. Many field observations were conducted until now, and those observation data have been used for global estimation of Rs. However, observations were mainly conducted in forests, croplands and grasslands, major terrestrial ecosystems. Observations for Rs in coastal sand dunes are totally limited, and there is no example of Rs measurement in coastal sand dunes with consideration for zonal distribution of coastal vegetation.
To examine the spatio-temporal variation of Rs and related mechanisms in coastal sand dunes, we conducted field observations for Rs and environmental parameters from June to December in 2020 in coastal sand dunes in Tottori, Japan. We set four measurement plots (n = 10 in each plot) in the study site representing bare sand (plot 1), clusters of Vitex rotundifolia (plot 2), Mixture of V. rotundifolia and Artemisia capillaris (plot 3) and boundary area between a pine forest (Pinus thunbergii) and coastal vegetation zone (plot 4). In those measurement plots, we conducted Rs measurement once in two weeks using portable automated chamber measurement system. At the same time, environmental parameters like air temperature, soil temperature and soil moisture were continuously measured using environmental measurement system that composed of car battery, data logger (CR1000, Campbell Scientific Inc.), solar panel, temperature (thermocouples) and soil moisture sensors (CS616, Campbell Scientific Inc.).
Rs was exponentially increased along with the temperature rise in plot 1 and 2. Such exponential increase was also confirmed in plot 3 and 4 if we excluded data in August (remarkably small Rs) under drought stress because of little rainfall. In addition, significant relationships between soil moisture and temperature-normalized Rs were also confirmed in plot 2, 3 and 4. Those results suggested that soil temperature is the primary environmental factor caused for seasonal variation of Rs, but soil moisture can also demonstrate strong influence on Rs as drought stress in summer period in this study site. In this presentation, mechanisms for spatio-temporal variation of Rs will be also discussed including the analysis for sand CN, root biomass and microbial community.
Soil respiration (Rs) is one of the largest carbon flux components in terrestrial carbon cycle. Many field observations were conducted until now, and those observation data have been used for global estimation of Rs. However, observations were mainly conducted in forests, croplands and grasslands, major terrestrial ecosystems. Observations for Rs in coastal sand dunes are totally limited, and there is no example of Rs measurement in coastal sand dunes with consideration for zonal distribution of coastal vegetation.
To examine the spatio-temporal variation of Rs and related mechanisms in coastal sand dunes, we conducted field observations for Rs and environmental parameters from June to December in 2020 in coastal sand dunes in Tottori, Japan. We set four measurement plots (n = 10 in each plot) in the study site representing bare sand (plot 1), clusters of Vitex rotundifolia (plot 2), Mixture of V. rotundifolia and Artemisia capillaris (plot 3) and boundary area between a pine forest (Pinus thunbergii) and coastal vegetation zone (plot 4). In those measurement plots, we conducted Rs measurement once in two weeks using portable automated chamber measurement system. At the same time, environmental parameters like air temperature, soil temperature and soil moisture were continuously measured using environmental measurement system that composed of car battery, data logger (CR1000, Campbell Scientific Inc.), solar panel, temperature (thermocouples) and soil moisture sensors (CS616, Campbell Scientific Inc.).
Rs was exponentially increased along with the temperature rise in plot 1 and 2. Such exponential increase was also confirmed in plot 3 and 4 if we excluded data in August (remarkably small Rs) under drought stress because of little rainfall. In addition, significant relationships between soil moisture and temperature-normalized Rs were also confirmed in plot 2, 3 and 4. Those results suggested that soil temperature is the primary environmental factor caused for seasonal variation of Rs, but soil moisture can also demonstrate strong influence on Rs as drought stress in summer period in this study site. In this presentation, mechanisms for spatio-temporal variation of Rs will be also discussed including the analysis for sand CN, root biomass and microbial community.