That research at the IGÖ is also interesting for small and hobby gardeners was perhaps only known to institute insiders until now. In the well-known gardening magazine 'Kraut und Rüben', Dr. Matthias Beyer from the Isodrones working group gave an interview on a process that is little studied and understood, but which may be immensely important in the face of climate change: hydraulic redistribution. Hydraulic redistribution refers to the passive, nocturnal transport of water due to soil moisture or water potential gradients in the soil (see figure). The water redistributed in this way is available the next morning to the 'redistributing' plant, but also to other plants. A simple example of this: During a drought in summer, the topsoil has completely dried out, but there is still enough water available at depth (e.g. groundwater). If there are now plants that are able to develop deep roots, there is the possibility that water from the deep soil layer is redistributed via the plant roots and released again in the upper, very dry soil layers.
It has been scientifically proven that the process takes place in all climatic zones and can be 'carried out' by very many deeper-rooted plant species. However, there are hardly any studies investigating the larger-scale significance of hydraulic redistribution - one main reason for this is the difficult and costly metrological recording. In the past, the IGÖ has already carried out some field experiments together with the Julius Kühn Institute (JKI, Dr. F. Feldmann) and the Institute of Geophysics and Extraterrestrial Physics (IGEP, Prof. Bücker). A larger project proposal is now planned to investigate hydraulic redistribution on a larger scale and in diverse ecosystems (forests, agricultural systems, allotments). In the interview, Dr. Beyer talks about the relevance of hydraulic redistribution for allotment gardeners - they too can and must adapt to climatic changes. The intelligent use of hydraulic redistribution, e.g. by deliberately planting deep-rooted plant species and trees, can be an important component. The full interview is in the September issue of 'Kraut und Rüben'. There is a free digital trial subscription. If you are interested in the article, Dr Beyer can be contacted at matthias.beyer(at)tu-bs.de.
The digital edition is available here: www.dlv-shop.de/zeitschriften/kraut-rueben/digitale-ausgabe-probelesen-2673