New and recent Journals/Newsletters/Books/Reports

Van Duinen, G.-J., Bobbink, R., Van Dam, C., Esselink, H., hendriks, R., Klein, M., Kooijman, A., Roelofs, J. & Siebel, H. 2004. Duurzaam natuurherstel voor behoud van biodiversiteit. Expertisecentrum LNV, Ede, 240 p (in Dutch)

Overview of the important results of the Dutch “Nature Survival” programme dealing with the successes and failures of restoration of nature conservation values in the Netherlands in the past 15 years. In the 1980s natural diversity was severely threatened in the Netherlands, one of the most densely populated areas of the world. This has led to an ambitious governmental programme of nature restoration since 1989. In contrast to many other countries, where interventions are based on intuition and actionism, practical restoration and mitigation measures were combined with in-depth scientific research to an extent that is unique in the world.

The approach included a comparison of the major parameters of disturbed/damaged and pristine ecosystems followed by process oriented laboratory research. The insights from that research successfully applied in the field. Almost half of the book is dedicated to the experiences in mires, both bogs – especially the problems associated with nitrogen deposition and the positive effect for Sphagnum re-establishment of CO₂ availability from peat mineralization – and fens – with much attention to hydrochemistry and sediment chemistry. Special attention is paid to the fauna, a neglected field in restoration research. Animals require other restoration conditions than plants and vegetation. For more information: Gert-Jan van Duinen: duinen@sci.kun.nl

Lucassen, E.C.H.E.T. (2004) Biogeochemical constraints for restoration of sulphate-rich fens. PhD Thesis, University of Nijmegen, 150 p

In this thesis, biochemical processes occurring in sulphate-rich groundwater fed fens are studied under two hydrological conditions: semi-natural conditions with a continuous input of base-rich and iron-rich groundwater, and conditions in which groundwater input is strongly decreased as a consequence of damming surface water. The aim of this study was to find out which factors and processes are responsible for the observed change in vegetation (from plants characteristic of mesotrophic to highly eutrophic conditions) and to determine biogeochemical constraints for the restoration of dessicated sulphate-rich fens.

Under semi-natural conditions, the continuous input of groundwater supplies fens with bivalent cations (iron. calcium and magnesium) and electron acceptors for the microbial breakdown of organic matter (iron, nitrate, sulphate). High inputs of bivalent cations via the groundwater lead to saturation of the sediment adsorption complex in seepage zones, preventing the binding of NH₄⁺ which is then continuously removed via the flowing groundwater. So a high input of bivalent cations via the groundwater results in restricted ammonium availability in fens. The continuous input of iron(hydr)oxides also increases the capacity of the aerobic sediment top layer to bind phosphate resulting in a decreased mobilisation of phosphate from the sediment to the water layer. Next to this, reduced iron is capable of binding sulphide in the sediment restricting mobilisation of phosphate in the sediment due to the interaction of sulphide with iron-phosphate complexes. Under semi-natural conditions the formation of iron-sulphides is restricted as sulphate reduction is inhibited in the presence of high iron and nitrate concentrations which are energetically more favourable electron acceptors. Immobile iron-sulphides are oxidised as a consequence of periodic drought during summer, regenerating immobile iron(hydr)oxides capable of binding phosphate, while mobile sulphate is removed via the flowing water layer when groundwaler input reincreases. Oxidation of iron-sulphides also leads to the production of acid. The sensitivity of sediments to drought, acidification, and mobilisation of heavy metals depends upon the amount of iron-sulphides and the buffering capacity of the sediment. In contrast to seepage zones that never dry out, periodic drought of parts outside seepage zones mostly will not lead to strong acidification as no accumulation of iron-sulphides takes place. Periodic drought also leads to oxidation of ammonium and formation of nitrate which diffuses to deeper anaerobic sediment layers where it is denitrified resulting in the production of nitrogen gas that disapears into the atrnosphere (a process called coupled nitrification-denitrification).

Under these mesotrophic conditions, fens are dominated by a species-rich Calthion-vegetation characterised by species 1ike marsh marigold (Caltha palustris). swamp horsetail (Equisetum fluviatile). greater spearwort (Ranunculus flammula) and many Carrex-species including elongated sedge (Carex elongata) and cyperus sedge (Carex pseudocyperus).

Increasing water levels in desiccated fens by damming surface water leads to a decreased groundwater input and thus to a restricted supply of base cations and the electron acceptors (iron and nitrate). The lower input of bivalent cations leads to increased binding of ammonium to the sediment adsorption complex resulting in a higher ammonium availability in the pore water. Reduction of sulphate is no longer inhibited as iron and nitrate are depleted. Produced sulphide will reduce iron from iron-phosphate complexes resulting in phosphate mobilisation. By maintaining permanent high water tables, no periodic drought occurs during summer. As a consequence, iron-sulphides are not oxidised and the concentration of iron capable of binding phosphate remains low. Thus in stagnating surface water, nutrient availability in the sediment is high and accumulation of nutrients to the stagnating water layer takes place. The increased sulphide concentrations in the sediment are toxic to Calthion-vegetation. Black alder (Alnus glutinosa) dies, falls down, and light intensity increases. The increased light intensity, in conjunction with the increased nutrient availability, leads to massive growth of Lemna minor and fast growing wetland grasses. Glyceria fluitans and Glyceria maxima are capable of detoxifying sulphide outside the plant as they have high radial oxygen losses at the roots. Lemna minor can completely cover the water surface when phosphate concentrations in the water layer are high. As a consequence, less oxygen diffuses to the water layer and the water layer can become anaerobic which further stimulates the mobilisation of phosphate from the sediment to the water layer.

For a successful restoralion of desiccated fens, they have to be gradually rewetted, with regular desiccation periods included, in order to allow a Fe pool to build up in the desiccated sediments. The adverse effects of SO₄^2- accelerate with rising water tables. Building up an Fe pool makes the previously desiccated pars of fens less sensitive to SO₄^2- reduction in periods when groundwater inputs are relatively high. In addition, stagnation of surface water should be avoided. Water tables can be raised without causing stagnation of surface water by raising them to below the potential groundwater table. This maintains a positive groundwater pressure, which enables continuous flow-through of groundwater, supplying base cations and electron acceptors to the system. Finally, periodic drought during summer is important in oxidising reduced Fe compounds in the sediment and thus in re-increasing the content of Fe(III) capable of binding o-PO₄^3-. Periodic drought can be achieved by making use of a controllable dam.

Gorissen, I. (2004) Dwarf shrub heaths of Europe – from Atlantic to Caucasus and Ural. Verlag Ingmar Gorissen, 182p (in German and English)

This lushly illustrated book discusses European dwarf shrub heaths on oligotrophic-acid soils in all their floristic diversity. The book addresses questions of how to characterise the European habitats in a global context, addresses the diversity and variations of European dwarf shrub heaths, and identifies heath-regions and centres of heath-biodiverstiy. Above all it is a catalogue of the 68 heath-regions that were identified, beautifully and richly illustrated with colour photographs of plants and landscapes.

For a table of contents and some sample pages, surf to: http://www.marz-kreations.com/WildPlants/Promo.htmlAvailable from Ingmar Gorissen, gorissen@team4-landschaftsplanung.de

Brugués, M., Muñoz, J., Ruiz, E. & Heras, P. (2004) Flora Briofitica Iberica: Sphagnaceae: Sphagnum. Spanish Society of Bryology (SEB: Sociedad Española de Briologia), Murcia, 79 p

When thinking about Mediterranean landscapes, olive groves, cork oak forests, and vineyards might come in mind first… Although the Iberian Peninsula is poor in extensive peatlands, you can find lots of European mire species, vascular plants as well as mosses, in different kinds of microhabitats.

As an important jigsaw piece for the investigation and understanding of wetlands on the Iberian Peninsula, the Spanish Society of Bryology (Sociedad Española de Briologia, SEB) recently published the new volume of the series Flora of Iberian Bryophytes (Flora Briofitica Iberica) devoted to the genus Sphagnum (Sphagnaceae).

The authors give a short introduction to the Genus, mentioning the most important morphological features. They also present two keys to all 29 species in 7 sections of Sphagnum found on the Iberian Peninsula. While the first key works on the basis of microscopical characteristics, the second one is based on macroscopical features and therefore enables identification in the field.

This is followed by a detailed description of each species, containing the current correct name, its synonyms in former publications, morphological features, habitat types and ecology, geographic range, type material, and the most important distinguishing features to similar species.

Unfortunately there are no geographic range maps, which would have been very helpful for people who cannot handle all the names of Spanish and Portuguese Provinces and their abbreviations. A clearly arranged reference list at the end would have been helpful, too.

The volume is written in Spanish, therefore people who do not speak Spanish or just a little might have some problems working with it.

Lapshina, E.D. (2003) Flora of South-East West Siberian mires. Tomsk University Press, Tomsk, 294 p. (in Russian).

A result of more than 20 years of intensive study of the flora and vegetation of West Siberian mires by our Main Board member Elena Lapshina (Professor at Tomsk University and Ugra State University, Khanty-Mansyisk). The book is divided into five chapters: The natural conditions of the West Siberian plain; floristic methods and a short overview on the vegetation of South-East West Siberian mires; vascular plants and mosses of the South-East West Siberian mires; analysis of their flora; conservation.

The most outstanding contribution of this book to the international community of mire scientists is the inventory and detailed description of 344 vascular plant species and 242 moss species occurring on South-East West Siberian mires.

The annex provides information on the occurrence on mires, areal distribution, and ecology (water conditions, trophic state, plant communities) of all these species. In addition, their frequency in different mires landscapes (e.g. forested valley mires, groundwater-fed forested mires, calcareous brownmoss fens, meso-oligotrophic pine-Sphagnum mires, open ombrotrophic Sphagnum mires, forested ombrotrophic Sphagnum mires) is described.

For further information and book orders, please contact Elena Lapshina: edlapshina@hotmail.com (FT)

Peat is still abundantly used in gardening, but the peat resource is declining and its extraction causes major damage to natural habitats. This brochure presents alternatives, with special attention being payed to composts.

It can be downloaded from: http://www.english-nature.org/pubs/publication/PDF/ CompPeatFree.pdfOr surf to www.imcg.net and look under peat alternatives.

Tourbières-INFOS n°10 – Novembre 2004 Tourbières-infos is a publication of the French spider in the peatland web Pôle-relais Tourbières. Their 10^th Newsletter has been released recently, surf to:

Paulissen, M. 2004. Effects of nitrogen enrichment on bryophytes in fens. PhD thesis Utrecht, 134 p.

Thesis consisting of 4 papers, an introduction, and a general conclusions dealing with the role of increased nitrogen availability on the decrease of characteristic brownmosses from dutch alkaline fens, i.c. Scorpidium scorpioides, Campylium stellatum, and Fissidens adianthoides, and the increase of acidiphytic moss species like Sphagnum fallax, S. palustre, S. squarrosum, and Polytrichum commune. Greenhouse experiments showed that brownmosses are more sensitive to ammonium fertilization than Sphagnum or Polytrichum species because the former are less able to detoxify ammonium. In the Netherlands 10 – 123 more ammonium is available in the moss layer than in a cleaner area in Ireland. This points at the necessity to decrease ammonium emission from intensive husbandry in the Netherlands.

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