I-.\~· . ,. s~ ,·8~, I ~'8 rlR , Staatsbosbeheer ?I~'i~ , :: ~. ~i~t rl/!~,J ',' ~:, r•..; ,1;1' .. fl.' i\C: . '1[;;, THE HYDROLOGY OF BOG ECOSYSTEMS I ,. Guidelines for management I I I I I I I tl • J.G. Streefkerk and W.A.Casparie __________ - .. - .. - i- ---- , I I I THE HYDR a LOG Y a F BOG E COS YST EMS I GUIDELINES FOR MANAGEMENT J.G. Streefkerk 1 & W.A. Casparie 2 1 2 Staatsbosbeheer, Dutch National Forestry Service, Utrecht. I Biologisch-Archaelogisch Instituut, State University, Groningen. I Published in 1989, Staatsbosbeheer I I I t ...... i I I I .,, I " , --- -- -- -- I • I I TAB LE o F CON TEN TS PREFACE I PART I- THE HYDROLOGY OF BOG ECOSYSTEMS I 1. INTRODUCTION 4 1.1 Raised bog in the Netherlands and its general significance 4 I 1.2 The hydrological problems of the existing bog remnants 5 SPATIAL AND TEMPORAL ASPECTS AND CONDITIONS FOR THE INITIATION I OF THE FORMATION OF BOG 6 2.1 General 6 I 2.2 Origin and development; aspects of time and space 7 2.2.1 General 7 2.2.1 The earliest peat deposits 9 I 2.2.2 The formation of fen peat 10 2.2.3 The marginal zone of a fen, and the lagg-zone of a bog 11 2.2.4 Seepage peat 11 2.2.5 The start of ombrogenous peat formation 12 I 2.2.6 Highly humified Sphagnum peat 12 2.2.7 Hummock - hollow systems and dome shaped complexes 13 2.2.8 Poorly humified Sphagnum peat and bog pools 16 I 2.2.9 Contact zones and bog lakes 17 2.3 Initial conditions for the formation of ombrogenous peat 18 I 2.3.1 Initial conditions of the (mineral) subsoil, which can result in the development of Sphagnum peat 18 2.3.2 Peat producing substrates, originated in the past, in which increasing oligotrophic conditions played a role at the start I of raised bog development 19 2.3.3 Strongly changed hydrological conditions caused by recent or I subrecent human influences 21 3. CLIMATE DUTCH BOGS IN EUROPEAN CONTEXT 22 I 3.1 General' 22 3.2 Climate and bog in Europe; spatial aspects 23 3.2.1 Distribution and typification of ombrotrophic peatlands in I Europe 23 3.2.2 Distribution of bogs in the Netherlands in relation to the I climate 28 3.3 Climate and bog; temporal aspects 30 3.3.1 Peat growth and climatic trends 30 I 3.3.2 Meteorological research into the trends of climate 35 I 3.4 Conclusion 37 I I 4. ECOLOGICAL ASPECTS OF BOGS 39 4.1 General 39 4.2 Moisture and nutrient balance of Sphagna 39 4.2.1 Internal and external moisture balance 39 4.2.2 Nutri ent; balance 41 4.3 Specific abiotic characterics of bogs 42 4.3.1 Morphology of the bog-surface in relation to the water-balance 42 I ::.- .._--4:3·.·2·-- . Characterisafion-of'·acrotelm· and-:catotelin~·-··--.-=-=-c-cc.:---::_·_ 45-::- ~::: 4.3·.3 System-linked discharge 51 4.3.4 Ombrotrophy as characteristic of raised.bogs. 55 4.4 Conclusion 59 5. SOME iMPORTANT HYDROLOGICAL CHARACTERISTICS DERIVED FROM STUDIES' OF WATER-BALANCE IN RAISED BOGS, IN 'PARTICULAR FOR THE DUTCH SITUATION 61 5.1 GeneraL 61 5.2 The equation of water-balance of raised bogs 61 5.3 Conclusions derived 'from water-balance studies of living raise4 bogs from some countries in Europe carried out over more than one year '. 63 I 5..3.1 Precipitation 63 5.3.2 Precipitation and evaporation of bogs, measured from the western to the of east Europe, and for the Dutch situation in. particular 63 I 5.3.3 The relaionship between precipitation and discharge from bogs, going from west to east, and in particular under Dutch condi­ tions 65 I 5.4 Further considerations of evaporation 67 5.4.1 Mean yearly evaporation of raised bogs with different vege­ tation cover 67 I 5.4.2 Evaporation of Sphagna . 68 5.5 Surface discharge from raised bog areas 69 I 5.6 Discharge via the substratum; in particular downwards seepage 71 5.6.1 Horizontal and vertical permeability of the peat 71 I 5.7 Example of the water-balanc~·of a living raised bog for the Dutch situation 73 I 5.8 Conclusions 75 I I I I • I I 6. CULTURAL-HISTORICAL DEVELOPMENT; THE END OF RAISED BOG FORMATION ON A LARGE SCALE AND STARTING POINT OF THE I PRESENT-DAYMANAGEMENT OF RAISED BOG 76 6.1 General 76 I 6.2. Reclamation of raised bogs on a large scale 77 6.3 The effect of shrinkage due to drainage d~tches in living raised bog 78 6.4 Peat digging; from raised bog to exploitation landscape 80 6.5 Points of departure for present day raised bog management 82 6.5.1 Lightly drained, uncut remnants of raised bog; (left after the growing of buckweed which involves the burning-off of the peat surface) . 82 6.5.2 Moderately drained, uncut raised bog remnants; (left after agrjculture on the bog surface) 83 6.5.3 Partly dug-away remnants of raised bog 83 6.5.4 Peat remnants which are almost completely cut-away 83 6.5.5 Completely cut-away raised bog (no peat remaining) 84 I 6.5.6 Agricultural soils which remain after peat cutting 84 6.6 Raised bog management ~tarting from other situation 84 6.6.1 Pingo ruins 84 6.6.2 Cut-off valleys of streams 85 I 6.6.3 Blown-out depressions, bowls 85 6.6.4 Perched bogs 86 6.6.5 Depressions of boulder clay 86 I 6.6.6 Oxbows 86 6.6.7 Antropogenic situations 86 I PART II - POINTS OF DEPARTURE FOR MANAGEMENT 7. INTRODUCTION 88 I 8. AIMS FOR MANAGEMENT, POSSIBILITIES AND LIMITING CONDITIONS FOR RAISED BOG FORMATION; IN PARTICULAR FOR THE DUTCH SITUATION 89 I 8.1 Aims for management 89 8.2 Possibilities for the formation of raised bog in general 89 I 8.2.1 Climatological possibilities 89 8.2.2 Pedological possibilities 90 8.3 Limiting conditions for the formation of raised bog in the I Netherlands 90 8.3.1 Limiting conditions for the formation of raised bog, contrallable and not-controllable 90 I 8.3.2 Controllable limiting conditions 91 8.3.3 Hydrological limiting conditions for the information of raised I bog 91 I I 93 8.4 Conclusions 9. HYDROLOGICAL MANAGEMENT OF RAISED BOG IN THE NET~ERLANDS 9.4 9.1 General 94 9.2 Air pollution and its possible influence on raised bog 94. 95 . 9.3 The effects of drainage and peat cutting on raised bog 9.3.1 Surface drainage of raised bogs .u.. I ----:'=9:~3_:2- -Cutting away of -raisedCoog -and::"drainage oFtlie surrounding" -.- land. 99 9.3.3 Summary of the problematics of the Dutch raised bogs 106 9.4 Regeneration of raised' bog; the creation of conditions for the .growth of oligotrophic peat 106 9.4.1 The regeneration of still surviving, dried out raised bog remnants 107 9.4.2 The regeneration of raised bog on partly cut away remnants of raised .bog 112· 9.4.3 Growing·in with vegetation of lake in a more nutrient rich environment 114. 10. SUMMARY '117 Appendix. 1 119 Appendix 2 120 I I I I I I I I I ~----------------- I - 1 - I PREFACE I Directions for the reader This report is concerned with the hydrological aspects of peat bog growth. Part I gives the setting for the formation of peat while part II discusses I mainly questions of management. .. -" -- It is primarily intended to aid managers of peat reserves in identifying possibilities for the regeneration of peat growth, so that these options may be I included in management plans for the conservation of bog lands. The report consists of two parts. Part I contains chapters 1 to 6, in which fundamental information is given on the spatial, historical and hydrological I aspects of peat formation. Point of departure for this part of the report is the question: Can the formation of peat, which took place over large areas of Western Europe I in the.past, be explained with the aid of knowledge of the hydrology and stratigraphy of bogs in the Netherlands? The extensive hydrological knowledge of peat-lands is analysed and this I information is tested against up to date stratigraphical opinion, the specific ecological characteristics of peat formation is also discussed. For a division of the types of peatland from an ecological and landscape point of view see e.g. Succow (1980, 1982) id. I A description of the present status of knowledge with regard to the types of peat-land is not included, although this would be a refinement. In fact the emphasis of this part of the report lies on the general understanding of the I formation of peat. Part II contains chapters 7 to 9 and discusses the possibilities for I management, using the information of part I. The central question here is: Is it possible to create conditions suitable for the formation or the maintenance of ombrotrophic and actively growing bog ecosystems, in the nature reserve areas of the Netherlands? I The two disciplines hydrology and palaeobotanical peat research are integrated in this report. The conclusions of both parts of the report are not directly intended as a manual for the manager of a reserve, but the conclusions indicate" I possibilities for management.