<p>Evapotranspiration (ET) is a complex phenomenon that responds to soil wa... more <p>Evapotranspiration (ET) is a complex phenomenon that responds to soil water availability, plant development, weather variations and climate change in many magnitudes, from leaf to ecosystem scale. Disentangling the different sources contributing to the total ET at the ecosystem level could contribute to a better understanding of the single process and the overall ET dynamics.</p><p>To tackle this goal, we established an Eddy Covariance station in a vineyard in Caldaro, South Tyrol, Italy, where cv. Chardonnay and cv. Sauvignon blanc are cultivated. The vineyard soil is covered by grasses and drip irrigation is available. We attempted to partition the total evapotranspiration (ET<sub>ec</sub>) data obtained into the vines transpiration (T<sub>v</sub>), the vines’ canopy evaporation (E<sub>v</sub>) and the understory evapotranspiration (ET<sub>u</sub>), the latter comprising the soil evaporation and the transpiration of the ground-level vegetation. By this Ecophysiological Partitioning Approach (EPA) the ecosystem ET<sub>EPA</sub> is the sum of T<sub>v</sub>, E<sub>v</sub> and ET<sub>u</sub>.</p><p>T<sub>v</sub> was estimated upscaling the sap flow rate measured via Sap Flow sensors (SFM1, ICT International,  Armidale, NSW, Australia; 3 sensors, 1 sensor per plant). ET<sub>u</sub> was assessed with 3 transparent soil-ground-flux-chambers and a multiplexer (Li-8100 Licor Biosciences, Lincoln, NE, USA) in 6 campaigns of 72 hours each, with the chambers being moved to a new position every 24 hours to cover time and spatial variability. E<sub>v</sub> was assessed by means of three leaf wetness sensors placed within grapevine canopy. All the measurements were set at 30-minutes intervals, to match the frequency of ET<sub>ec</sub>.</p><p>Preliminary results of this ongoing project, which forsees two years of field measurements, showed that ET<sub>ec</sub> amounted to 545 mm during the growing season 2021, with values ranging from 0.33 to 4.83 mm d<sup>-1</sup>. ET<sub>ec</sub> correlated well with net radiation and with ET<sub>u</sub>. All sap flow sensors showed a similar trend across the season, consistent with ET<sub>ec</sub>, but differed among each other in terms of flow quantities, likely due to wood specificities of each sampled grapevine which will require specific on-site calibrations.</p><p>E<sub>v</sub> component, rarely considered in ET partitioning studies, was strongly dependent on precipitation pattern and we hypothesize it can offer a gain of more than 5% in explaining the ET dynamics in the experimental vineyard, wether compared to removing wet canopy moments from the dataset.  </p><p>Once the calibration of the soil-ground-flux-chambers system and the installed sap-flow sensor be improved, in-situ measurements of components of ET<sub>EPA</sub> will contribute to a computational partitioning approach which improves the comprehension of the dynamics of the ecosystem ET sources under climate change.</p>
Traditional agricultural systems are receiving increasing attention at the international level du... more Traditional agricultural systems are receiving increasing attention at the international level due to their multifunctional role. The Globally Important Agricultural Heritage Systems (GIAHS) programme of the Food and Agriculture Organization (FAO) aims to identify agricultural systems of global importance, preserve landscape, agrobiodiversity and traditional knowledge and apply the principles of dynamic conservation to promote sustainable development. Biodiversity associated to traditional agricultural practices is particularly important, especially in difficult environments, like traditional oases, for ensuring food and nutrition to local communities. We documented landscape and biological diversity associated with traditional agricultural practices in three traditional oases in Tunisia, through a landscape analysis based on land-use survey, and an assessment of cultivated species. Results show that the landscape structure is dominated by agricultural land uses and characterized by...
<p>Evapotranspiration (ET) is a complex phenomenon that responds to soil wa... more <p>Evapotranspiration (ET) is a complex phenomenon that responds to soil water availability, plant development, weather variations and climate change in many magnitudes, from leaf to ecosystem scale. Disentangling the different sources contributing to the total ET at the ecosystem level could contribute to a better understanding of the single process and the overall ET dynamics.</p><p>To tackle this goal, we established an Eddy Covariance station in a vineyard in Caldaro, South Tyrol, Italy, where cv. Chardonnay and cv. Sauvignon blanc are cultivated. The vineyard soil is covered by grasses and drip irrigation is available. We attempted to partition the total evapotranspiration (ET<sub>ec</sub>) data obtained into the vines transpiration (T<sub>v</sub>), the vines’ canopy evaporation (E<sub>v</sub>) and the understory evapotranspiration (ET<sub>u</sub>), the latter comprising the soil evaporation and the transpiration of the ground-level vegetation. By this Ecophysiological Partitioning Approach (EPA) the ecosystem ET<sub>EPA</sub> is the sum of T<sub>v</sub>, E<sub>v</sub> and ET<sub>u</sub>.</p><p>T<sub>v</sub> was estimated upscaling the sap flow rate measured via Sap Flow sensors (SFM1, ICT International,  Armidale, NSW, Australia; 3 sensors, 1 sensor per plant). ET<sub>u</sub> was assessed with 3 transparent soil-ground-flux-chambers and a multiplexer (Li-8100 Licor Biosciences, Lincoln, NE, USA) in 6 campaigns of 72 hours each, with the chambers being moved to a new position every 24 hours to cover time and spatial variability. E<sub>v</sub> was assessed by means of three leaf wetness sensors placed within grapevine canopy. All the measurements were set at 30-minutes intervals, to match the frequency of ET<sub>ec</sub>.</p><p>Preliminary results of this ongoing project, which forsees two years of field measurements, showed that ET<sub>ec</sub> amounted to 545 mm during the growing season 2021, with values ranging from 0.33 to 4.83 mm d<sup>-1</sup>. ET<sub>ec</sub> correlated well with net radiation and with ET<sub>u</sub>. All sap flow sensors showed a similar trend across the season, consistent with ET<sub>ec</sub>, but differed among each other in terms of flow quantities, likely due to wood specificities of each sampled grapevine which will require specific on-site calibrations.</p><p>E<sub>v</sub> component, rarely considered in ET partitioning studies, was strongly dependent on precipitation pattern and we hypothesize it can offer a gain of more than 5% in explaining the ET dynamics in the experimental vineyard, wether compared to removing wet canopy moments from the dataset.  </p><p>Once the calibration of the soil-ground-flux-chambers system and the installed sap-flow sensor be improved, in-situ measurements of components of ET<sub>EPA</sub> will contribute to a computational partitioning approach which improves the comprehension of the dynamics of the ecosystem ET sources under climate change.</p>
Traditional agricultural systems are receiving increasing attention at the international level du... more Traditional agricultural systems are receiving increasing attention at the international level due to their multifunctional role. The Globally Important Agricultural Heritage Systems (GIAHS) programme of the Food and Agriculture Organization (FAO) aims to identify agricultural systems of global importance, preserve landscape, agrobiodiversity and traditional knowledge and apply the principles of dynamic conservation to promote sustainable development. Biodiversity associated to traditional agricultural practices is particularly important, especially in difficult environments, like traditional oases, for ensuring food and nutrition to local communities. We documented landscape and biological diversity associated with traditional agricultural practices in three traditional oases in Tunisia, through a landscape analysis based on land-use survey, and an assessment of cultivated species. Results show that the landscape structure is dominated by agricultural land uses and characterized by...
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