2018-19 Soil Policy Evidence Programme Habitat Suitability Modelling Scoping Study 12th September 2019 Report code: SPEP2018/19-08 Mae’r ddogfen yma hefyd ar gael yn y Gymraeg. This document is also available in Welsh. © Crown copyright 2020 WG41030 ADAS GENERAL NOTES Project No.: 1021091-1(01) Title: Habitat Suitability Modelling Scoping Study Client: Welsh Government – Soil Policy Unit, Department for Environment, Energy & Rural Affairs Date: 12th September 2019 Office: Wolverhampton Status: Final Chris Forster-Brown, Dave Skirvin & Lucy Authors Wilson Technical reviewer Lucy Wilson Date: 12th Sept 2019 Date: 12th Sept 2019 ADAS Project manager Lucy Wilson Date: 12th Sept 2019 Welsh Government James Cooke Project Manager RSK ADAS Ltd (ADAS) has prepared this report for the sole use of the client, showing reasonable skill and care, for the intended purposes as stated in the agreement under which this work was completed. The report may not be relied upon by any other party without the express agreement of the client and ADAS. No other warranty, expressed or implied, is made as to the professional advice included in this report. Where any data supplied by the client or from other sources have been used, it has been assumed that the information is correct. No responsibility can be accepted by ADAS for inaccuracies in the data supplied by any other party. The conclusions and recommendations in this report are based on the assumption that all relevant information has been supplied by those bodies from whom it was requested. No part of this report may be copied or duplicated without the express permission of ADAS and the party for whom it was prepared. Where field investigations have been carried out, these have been restricted to a level of detail required to achieve the stated objectives of the work. This work has been undertaken in accordance with the quality management system of RSK ADAS Ltd. CONTENTS 1 INTRODUCTION ............................................................................................................. 1 1.1 Objectives ............................................................................................................................... 1 2 RESTORATION/ ESTABLISHMENT REQUIREMENTS OF THE MAIN TERRESTRIAL PRIORITY HABITATS IN WALES .................................................................................. 2 2.1 Lowland meadows ................................................................................................................. 2 2.2 Lowland calcareous grassland ............................................................................................ 2 2.3 Lowland dry acid grassland ................................................................................................. 3 2.4 Upland calcareous grassland .............................................................................................. 4 2.5 Coastal and floodplain grazing marsh ................................................................................ 4 2.6 Purple moor-grass and rush-pasture .................................................................................. 5 2.7 Arable field margins............................................................................................................... 6 2.8 Lowland heathland ................................................................................................................ 7 2.9 Upland heathland .................................................................................................................. 8 2.10 Blanket bog ............................................................................................................................. 9 2.11 Reedbeds ................................................................................................................................ 9 2.12 Upland oakwood .................................................................................................................. 10 2.13 Upland mixed ashwood ...................................................................................................... 10 2.14 Wet woodland ...................................................................................................................... 10 3 LINKING PRIORITY HABITAT REQUIREMENTS TO ALC LIMITING FACTORS ....... 12 3.1 Methodology ......................................................................................................................... 12 3.2 Results .................................................................................................................................. 17 4 GAPS IN ALC DATA FOR DESCRIBING ENVIRONMENTAL CONDITION REQUIREMENTS. ........................................................................................................ 32 4.1 Gaps in biophysical requirements of priority habitats .................................................... 32 4.1.1 Historical extent of habitats .................................................................................... 32 4.1.2 Multiple NVC types .................................................................................................. 32 4.1.3 Additional analysis of soil data .............................................................................. 33 4.1.4 Geology ..................................................................................................................... 33 4.2 ALC Data Gaps & Additional Technical Information / Evidence................................... 34 5 SCOPING A MODELLING PROJECT THAT COULD UTILISE SUCH A FRAMEWORK ...................................................................................................................................... 36 5.1 Work Package 1: Habitat requirements scoring ............................................................. 36 5.1.1 Datasets required .................................................................................................... 37 Welsh Government i Habitat Suitability Modelling Scoping Study Project no. 1021091 5.1.2 Resource estimates................................................................................................. 37 5.2 Work package 2: Development of a desktop-based tool for assessing land area suitability for priority habitats ............................................................................................. 38 5.2.1 Key steps .................................................................................................................. 38 5.2.2 Outputs ...................................................................................................................... 39 5.2.3 Resource estimates................................................................................................. 39 5.3 Additional cost option .......................................................................................................... 39 5.3.1 Combing ALC with plan species niche modelling tool ....................................... 39 5.3.2 Tasks required for the development of this approach ........................................ 40 5.3.3 Datasets required .................................................................................................... 41 5.3.4 Resource estimates................................................................................................. 42 6 POTENTIAL USES FOR SUCH A MODELLING SYSTEM ........................................... 43 6.1 Support for agri-environment scheme development ...................................................... 43 6.1.1 Flood risk reduction ................................................................................................. 43 6.1.2 Decarbonisation ....................................................................................................... 43 6.1.3 Habitat ....................................................................................................................... 43 6.2 Support for agri-environment management option selection ........................................ 44 6.3 Assessment of the implications of climate change ......................................................... 44 6.4 To inform land use choice .................................................................................................. 44 6.5 To help target expansion and restoration of the priority habitat network .................... 45 6.6 Area Statements .................................................................................................................. 45 7 REFERENCES .............................................................................................................. 47 Tables Table 1. Notes on Priority Habitat requirement tables............................................................. 12 Table 2. ALC soil texture class abbreviations ........................................................................... 15 Table 3. Definition of soil wetness class in the ALC ................................................................ 16 Table 4. Lowland meadows ......................................................................................................... 17 Table 5. Lowland calcareous grassland .................................................................................... 18 Table 6. Lowland dry acid grassland ......................................................................................... 19 Table 7. Upland calcareous grassland ...................................................................................... 20 Table 8. Coastal