Blog entry 1:

What is the impact of a higher interception on evapotranspiration and the final water use? Is interception diminishable?

Due to climate change and therefore rising temperature, water is going to be more and more the limited factor for plant growth. This urges people to be more sensitive at dealing with water. By minimising transpiration and evaporation water loss is getting reduced a lot. Another way to deal with that problem is to decrease the runoff (Prosdocimi et al., 2016). However, up to half of the water loss is on the account of the evaporation from water of wet canopy (van Dijk et al., 2015). To reduce this interception loss, plantations in Japan get thinned because, according to Tsukamoto, 1998 and Kuraji, 2003, found in Shinohara et al. 2015, the repellency of precipitation and therefore the interception of unthinned plantations is higher. This causes reduced runoff on a short-term and water loss. Furthermore, drops falling from canopy cause often more soil erosion than open rainfall as a result of their higher kinetic energy (Zhou et al., 2002 and Nanko et al., 2004 found in Shinohara et al., 2015). These drops disaggregate the soil structure which leads to a lower infiltration rate and therefore to more runoff on a long-term and a higher evaporation rate.

The tree nursery Zulauf Ag irrigates its plants with water from a pont. This water flues back into the pont again. Despite of this sophisticated circulation, the tree nursery needs to buy a lot of additional water. An option to decrease the amount of bought water could be to diminish the amount of evaporation of Intercepted water. This leads to the following questions:

Is interception at the tree nursery Zulauf Ag measureable? Does a higher interception loss make a big difference to water? Is there an opportunity to reduce interception at Zulauf Ag?

Prosdocimi, M., Jordán, A., Tarolli, P., Keesstra, S., Novara, A., & Cerdà, A. (2016). The immediate effectiveness of barley straw mulch in reducing soil erodibility and surface runoff generation in Mediterranean vineyards. The Science of the Total Environment, 547, 323–30. http://doi.org/10.1016/j.scitotenv.2015.12.076

Shinohara, Y., Levia, D. F., Komatsu, H., Nogata, M., & Otsuki, K. (2015). Comparative modeling of the effects of intensive thinning on canopy interception loss in a Japanese cedar (Cryptomeria japonica D. Don) forest of western Japan. Agricultural and Forest Meteorology, 214-215, 148–156. http://doi.org/10.1016/j.agrformet.2015.08.257

van Dijk, A. I. J. M., Gash, J. H., van Gorsel, E., Blanken, P. D., Cescatti, A., Emmel, C., … Wohlfahrt, G. (2015). Rainfall interception and the coupled surface water and energy balance. Agricultural and Forest Meteorology, 214-215, 402–415. http://doi.org/10.1016/j.agrformet.2015.09.006