GTN-P - Strategy and Implementation Plan 2016-2020

Permafrost is recognized as Essential Climate Variable (ECV) within the Global Climate Observing System of UN and ICSU organisations. The Global Terrestrial Network for Permafrost (GTN-P) is the primary international programme concerned with long-term monitoring of permafrost. The core mission of the GTN-P is sustained comprehensive long-term monitoring network, in order to provide consistent, representative and high quality standardized long-term data series of selected permafrost parameters at key sites and to assess their state and changes over time. The Strategy and Implementation Plan 2016-2020 outlines recent progress and future challenges facing the network. It describes the governance and management structure of GTN-P, linkages to regional and global observing systems, management process and reporting strategies. It presents measurement methods and protocols used in field data collection and state of the art data management system, which was recently designed and implemented to process, analyse, and visualize permafrost data. It concludes with the outlook of the future developments of the network in order to sustain and succeed its core mission of providing long-term observations and maintain the availability of data collected

52Fe Translocation in Barley as Monitored by a Positron-Emitting Tracer Imaging System (PETIS): Evidence for the Direct Translocation of Fe from Roots to Young Leaves via Phloem

The real-time translocation of iron (Fe) in barley (Hordeum vulgare L. cv. Ehimehadaka no. 1) was visualized using the positron-emitting tracer 52Fe and a positron-emitting tracer imaging system (PETIS). PETIS allowed us to monitor Fe translocation in barley non-destructively under various conditions. In all cases, 52Fe first accumulated at the basal part of the shoot, suggesting that this region may play an important role in Fe distribution in graminaceous plants. Fe-deficient barley showed greater translocation of 52Fe from roots to shoots than did Fe-sufficient barley, demonstrating that Fe deficiency causes enhanced 52Fe uptake and translocation to shoots. In the dark, translocation of 52Fe to the youngest leaf was equivalent to or higher than that under the light condition, while the translocation of 52Fe to the older leaves was decreased, in both Fe-deficient and Fe-sufficient barley. This suggests the possibility that the mechanism and/or pathway of Fe translocation to the youngest leaf may be different from that to the older leaves. When phloem transport in the leaf was blocked by steam treatment, 52Fe translocation from the roots to older leaves was not affected, while 52Fe translocation to the youngest leaf was reduced, indicating that Fe is translocated to the youngest leaf via phloem in addition to xylem. We propose a novel model in which root-absorbed Fe is translocated from the basal part of the shoots and/or roots to the youngest leaf via phloem in graminaceous plants