Atmospheric Deposition And Nutrient Cycling In Chalk Grassland

This book brings together two aspects of grassland soil management which, by and large, have hitherto been considered separately. Issues related to nutrient cycling and soil quality have dominated research directed towards aiding broad and local scale policy issues for improving land use. Protecting the environment and maintaining/preserving natural habitats and biodiversity, tend to be considered separately. In this book we attempt to bring what are, in reality, inseparable aspects of grassland soil characteristics together and consider physical, chemical and biological components of soils, their interrelations and the way that they influence nutrient transformations and flows and soil quality. Keynote discussions will be lead by the following experts: Physical constraints and drivers: Professor Iain Young, Abertay University, Scotland Biological aspects: Professor Tim Seastedt, University of Colorado at Boulder, USA Chemical aspects: Dr Mike Beare from Crop and Food, Research, Lincoln New Zealand Over-arching synopsis of these issues: Professor Richard Bardgett, Lancaster University, UK. Bringing together international expertise and experience does much to progress understanding and points ways forward to maintain what is a base resource, our soils, whether it be for production targets, environmental benefit or for maintenance of natural ecosystems for future generations. This volume is useful to all those interested in soils and their function, and all grassland managers, whether their aims are directed at producing food, forage or fibre of sustainable quantity and quality or at maintaining, restoring or encouraging above and below ground biodiversity. The international perspective on this is very important so that experiences in wide ranging circumstances can be cross-referenced and used to the advantage of all.

Emissions largely associated with the combustion of fossil fuels and agriculture has caused elevated atmospheric deposition of nitrogen (N) and sulfur (S) throughout much of the developed world. Increased atmospheric deposition of N and S can lead to soil and surface water acidification and affect forest soil nutrient supply. The critical load (CL) of atmospheric deposition is the level of deposition below which significant harm to ecosystems is not likely to occur. The critical load provides an understanding of the extent to which terrestrial and aquatic systems may be affected by air pollution at present or in the future. This research implements novel methods for generating CL estimates of N and S deposition and evaluates spatial and temporal trends in soil chemistry and plant biodiversity with respect to future climate and land management scenarios. Results are presented in the context of chemical thresholds known to be associated with adverse impacts to terrestrial and aquatic biota of the southern Appalachian Mountains and high elevation Colorado Rocky Mountains.

The book begins with an overview of the research topics which were addressed in the three different phases of the Dutch Priority Program on Acidification (DPPA), executed between 1985 and 1994. This chapter is followed by a chapter which deals with the emissions of acidifying substances, the concentrations and the deposition to forest and nature conservation areas. Prognoses are given for the acid deposition in 2000 and 2010; the deposition in the countries surrounding the Netherlands is also mentioned. The differences in the results of the DPPA-II are analysed. The third chapter deals with the effects of exposure and load on forests. The chapter moves from small-scale to large-scale: first the effects in laboratory-scale studies are described, then the effects in the field, both at stand level and on a regional scale. In addition, the critical thresholds (critical level of concentration and critical load of deposition) are discussed. The fourth chapter covers terrestrial ecosystems (or parts thereof) as well as weakly buffered surface waters, springs and other streams. Critical levels and loads are also discussed. The most important results are given in chapter 5. In the appendices of the book, so-called umbrella theme reports on deposition, stand modelling and effects on forests are presented which describe in more detail the scientific work performed in the third phase of the DPPA. This book will be of interest to anyone involved in research related to acidification and eutrophication; i.e., not only those who perform the research in the causal chain from emissions to effects, but also policy-makers and students.

In this book the research on atmospheric deposition of the Dutch Priority Programme on Acidification Research is summarised. Although most research described is of Dutch origin, it has been put into a broader perspective by outlining the state of knowledge on the process affecting atmospheric deposition in Europe. This has resulted in detailed deposition maps for the Netherlands and Europe. The volume is intended for those who measure or model atmospheric deposition and ecologists interested in exposure from atmospheric deposition, as well as policy-makers and students.