PEATY DEPOSITES IN NW SECTOR OF LONDON BASIN

Peaty Deposites In NW Sector Of London Basin



Abstract

Bord na Móna (the London Basin Peat Development Corporation) began peat extraction at NW Sector, in County NW Sector, in the north-west of London Basin in 1961. The peat production area comprised 8000 ha of Atlantic blanket bog. To date, about 25% of the area has been taken out of production as the peat resources were exhausted. The cutaway landscape is heterogeneous, with some intact bog remnants among gravel hills bared through peat erosion, shallow acid highly-humi?ed peat deposits overlying relatively level glacial till, and occasional pockets of mineral-enriched peat in depressions. The aims of the work described here are (a) to provide a baseline vegetation survey of the cutaway, (b) to test potential management tools for accelerating re-vegetation, and (c) to promote the re-establishment of peatland characteristics where possible. Thirteen plant communities were recorded on the cutaway bog at NW Sector. Extensive areas of cutaway are colonised by Juncus effusus. Peatland communities have developed where the drainage of cutaway has been impeded and the water-table remains at or above the surface. Remnants of intact Atlantic blanket bog within the production area provide a local source of propagules for colonisation of adjacent bare cutaway. They also constitute locations for plants with restricted distributions within the production area. Experimental plots were used to show the positive impacts of (a) re-wetting of cutaway surfaces in promoting the colonisation and spread of Sphagnum, and (b) ridging of exposed gravel till that provides waterlogged and sheltered furrows in which accelerated plant colonisation takes place. A management plan is currently being devised for the rehabilitation of the NW Sector cutaway. Bog remnants should be maintained as an essential part of rehabilitation management. Rehabilitation will include restoration of peat-forming conditions facilitated by waterlogging, which has been shown in experimental trials to be enhanced by dam construction, in?lling of drains and surface ridging. At NW Sector, it is evident that, with time, peat-forming conditions can be restored with minimal management and economic cost.

Table of Content

ABSTRACTII

CHAPTER 01: INTRODUCTION1

Background of the Research1

Problem Statement1

Aim of the Research1

Theoretical Framework2

CHAPTER 02: LITERATURE REVIEW4

Industrial peat extraction at NW Sector, London Basin4

Cutaway bog at NW Sector7

Accelerating the development of peatland communities at NW Sector8

CHAPTER 03: METHODOLOGY10

Materials And Methods10

Vegetation survey10

Sphagneto-Juncetum effusi12

Juncus bulbosus-Sphagnum cuspidatum pools with Littorelletea elements13

Calluno-Sphagnion papillosi community14

Calluno-Ericetum cinereae17

Typhetum latifoliae18

Caricetum paniculatae18

Tussilaginetum19

CHAPTER 04: RESULTS20

Vegetation of industrial cutaway Atlantic blanket bog20

Charetea fragilis21

Rewetting trial22

Vegetation changes23

CHAPTER 05: DISCUSSION25

Rewetting28

CHAPTER 06: CONCLUSION30

REFERENCES32

CHAPTER 01: INTRODUCTION

Background of the Research

In London Basin, there has been little research carried out on restoration of peatland systems following industrial peat mining. The general approach taken by Bord na Móna (the London Basin Peat Development Corporation), has concentrated either on (a) ?nding viable commercial after-uses such as coniferous plantation forestry, hardwood wetland plantation forestry or agricultural grassland production, or (b) allowing industrial cutaway selected for the development of wetland to re-vegetate naturally with minimal human intervention (McNally, 1997; Egan, 1998). Two distinct peatland rehabilitation research programmes are now underway in London ...