Objectives

The Transregional Collaborative Research Centre (SFB/TRR) 38 aims to investigate relevant structures and processes during the initial ecosystem development phase and their interactions, to differentiate them from those occurring in the later stages of ecosystem development.

The overall hypothesis is: The initial ecosystem development phase forms the later state of ecosystems.

For this reason, the collaborative research centre investigates an artificial water catchment starting from the point zero of its primary development in combination with experimental verifications of identified processes and structures including their interactions. The investigations focus on the analysis of initial development processes which are affected by existing and newly generated structures and the interpretation of their dependencies. It has been hypothesized that the initial ecosystem genesis can be divided into different phases of development (see Fig. below).

Fig.: Phases of the initial ecosystem development

The following central questions will be answered:

• Which abiotic and biotic structures and processes regulate the initial phase of ecosystem development?
• Which interactions exist particularly in the initial phase between the processes and abiotic and biotic structures?
• How can processes and structures of initial systems be distinguished (qualitatively and quantitatively) from more advanced stages of ecosystem development?
• Which structures and processes allow the definition of different stages of development (pedological, hydrological, biological etc.)?
• Which parameters allow for the transfer of results to other ecosystems in the initial phase?

The objective of the SFB/TRR 38 is to enhance integral models of structural genesis in ecosystems and of process dynamics as well as their interactions during the initial development phase. The integration of structure and process data will be realized by means of a comprehensive “structure and process model” which is to be developed within this collaborative project. This model will be the central tool for data aggregation and result integration. It will be used to elucidate and define the characteristic conditions and phases of the development.

The central research site of the SFB/TRR 38 is the artificially created water catchment 'Chicken Creek' ("Hühnerwasser") with an area of approximately 6 ha, left to undirected succession that allows the integrated analysis on a landscape scale. Boundary conditions of this site are clearly defined including well documented inner structures, as compared to natural catchments. These are important prerequisites for the validation and optimization of established water and element budget models.

Additionally an experimental site, in close proximity to the central site will be used to analyse the functioning of identified structure building processes by means of specific manipulations. Hence, specific interventions into the natural succession as well as the use of stable isotopes as tracers are planned.

In addition, investigations will be conducted at reference sites e.g. on inland dunes in Northeastern Germany as well as on a glacial front in the Swiss Alps. These additional sites allow for the differentiation between site-specific influences and universally valid process and structural patterns during the initial ecosystem development phase that can be applied to similar ecosystems and different site conditions.

In regards to its integral and system orientated approach, the size and the well defined boundary and initial conditions of the central research site, its catchment size and its stage of initial ecosystem genesis make this project is unique. Results are expected to be of great importance for the management of landscapes that have been degraded to an initial state by natural or anthropogenic disturbances.