Soil chronosequences are excellent model systems for testing ideas surrounding ecosystem development. Recent reviews by Wardle et al. (2004, Science 305:509-513) and Vitousek (2004, Nutrient cycling and limitation; Princeton University Press) demonstrate that ecosystem properties and processes follow somewhat predictable long-term trajectories across contrasting systems, in that they are driven is being driven initially by N limitation but ultimately by P limitation. Chronosequences offer a unique opportunity to explore or resolve many outstanding issues in ecology, including: what is the role of organic N and P nutrient sources for maintaining primary productivity or promoting plant species coexistence? Under what conditions should we expect retrogressive (i.e., decline) phases in ecosystem properties to develop? A symposium followed by a working group was held 29th Jan -- 1st Feb 2007. Here are the speakers and topics at the symposium:

David Wardle (Swedish University of Agricultural Sciences): Introduction to workshop.
Rob Allen (Science Leader, Landcare Research): Overview of the ARC-NZ Vegetation Network.
Thomas W. Walker (Christchurch): Introductory remarks.
Lawrence Walker ( University of Nevada): Predicting and reversing retrogression: autogenic change in a disturbed world.
Joe Walker (CSIRO): The Cooloola chronosequence and retrogression.
Peter Vitousek (Stanford University): Sources and sinks of nutrients during long-term ecosystem development.
Rob Allen (Landcare Research): Forest dynamics across the Waitutu marine terrace chronosequence.
Sarah Richardson (Landcare Research): Plant strategies and plant traits on retrogressive soils.
Duane Peltzer (Landcare Research): Shifts in plant traits along soil chronosequences.
Leo Condron ( Lincoln University) Changes in the chemical nature of soil organic P on the Franz Josef chronosequence.
Vicki Allison (Landcare Research): Controls on enzyme activity and efficiency along nutrient gradients at the Franz Josef chronosequence.
David Wardle (Swedish Univ of Agric Sciences): Aboveground and belowground responses to ecosystem retrogression.
Richard Bardgett (Univ. of Lancaster): Soil microbial community development during ecosystem build-up and decline.
Roger Parfitt (Landcare Research): Nitrogen and phosphorus in New Zealand forest soils.
Troy Baisden (GNS): Linking C, N and P as soils age: towards understanding the bulk of evolutionary time.
Ben Turner (Smithsonian Institute): The chronosequence concept and the paradox of hyper-diverse tropical forests. Oliver Chadwick (UC Santa Barbara): Mineral transformations as soils age: impact on carbon and trace metal availability.
Steven Porder (Stanford University): What do chronosequences tell us about the larger landscape?
Duane Peltzer (Landcare Research): Synthesis and wrap-up.