A modelling approach to locating and characterising elm decline/landnam landscapes

A pollen modelling approach is used to develop plausible landscapes for an area of central Ireland around the time of the elm decline and earliest agricultural clearances. This approach utilises the ability to simulate landscapes and determine pollen assemblages at points within that landscape based originally on extended R-value models and now using MOSAIC, POLFLOW and POLGRID. Following initial construction of a simulated purely artificial landscape to establish envelope conditions, plausible landscapes are reconstructed around a pollen site at Derragh Bog and pollen assemblages generated for three timeslices: pre-woodland decline, during the decline and at the period of minimum elm values. Simulated results from the landscape reconstruction are comparable to those found in the sub-fossil record and imply that Ulmus must have originally been a significant element in the local woodland (covering 40% of the total area), that almost 75% of the local landscape underwent change during the period of analysis and that open areas probably represented at least 12% of the vegetated landscape at the time of maximum openness.