Bridging Disciplinary Gaps in Studies of Human-Environment Relations: A Modelling Framework

Modern human-environment relations are problematic and difficult to analyse in terms of nature and culture. Many authors suggest to abandon and overcome the nature-culture dichotomy in order to reorganise the academic division of labour, not only on environmental questions. Anthropologist Philippe Descola, for example, surveyed the empirical evidence of patterns in humanenvironmental relations, suggesting four abstract cosmologies. Here, we propose a translation into a modelling terminology, which is compatible with the formalisation of programmes in computer science. The generalised framework contains four ideal types of modelling paradigms. It can be tested on various other classification schemes in a number of disciplines. In each application, the categories of classification can be translated and then the patterns of the four logic types can be compared with the phenomenology of each case. Implications for interdisciplinary cooperation between science and the humanities are sketched for some environmental issues. This work demonstrates how tools from computer science can help, metaphorically, conceptually and technically, to organise interdisciplinary exchanges between science and the humanities. The categorical approach of applying the “divide and conquer” technique to different disciplinary models serves as a yardstick for comparing the implicit logic and modelling assumptions across examples whose phenomenological contents appear as unrelated. It gives useful hints how a dilemma of choosing between rigorous or relevant models can be resolved (e.g., in environmental science) and how the nature-culture dichotomy might be replaced by a general and flexible framework of a few model types

Insight into hydrochemistry: a multi-catchment comparison using Horizontal Visibility Graphs

Long time series of environmental variables are reflecting the dynamics and functioning of ecosystems. Here, we investigate data from a long-term monitoring site in Germany, the Bramke valley in the Harz mountains, where time series of ion concentrations in stream water are obtained since the 1970ies at four measurement locations from three small adjacent forested catchments. Since for (only) one of the catchments daily runoff rates are also available, we invent a method to generate time series of nutrient output from the catchments. Both concentrations and outputs show a number of remarkable long-term changes, including ones not obviously related to changes in atmospheric deposition, management or properties of the forest stands. For the analysis of the Bramke data, we investigate Horizontal Visibility Graphs (HVGs), a recently developed method to construct networks based on time series. Values (the nodes of the network) of the time series are linked to each other if there is no value higher between them. The network properties, such as the degree and distance distributions, reflect the nonlinear dynamics of the time series. For certain classes of stochastic processes and for periodic time series, analytic results can be obtained for some network properties. HVGs have the potential to discern between deterministic-chaotic and correlated-stochastic time series. We classify the Bramke series according to their stochastic nature, with a focus on inter-catchment comparison on one hand, on different nutrients for one catchment on the other, and conclude on possible reasons for the observed changes and their ecological interpretation

Water and ion movement through a minicatchment at Risdalsheia, Norway (RAIN project)

At Risdalsheia (Southernmost Norway) the relation between flow paths and streamwater chemistry through a small headwater catchment was investigated. The importance of these pathways for the interaction between soil solution and runoff chemistry was investigated by a tracer experiment with LiBr. The experiment was designed using all available information about ion transport at EGIL-catchment in a simple model that predicted the breakthrough curve for a given tracer input. The unique facility of a roofed catchment allowed attainment and maintainace of a hydrological steady-state under highflow conditions during this tracer experiment. The chemical changes of the moving soil water due to soil/soil solution interaction mainly occured during vertical (unsaturated) infiltration. Most ions reached their runoff concentration levels after these few cm of vertical infiltration. Only the ions SO4, NO3, and H increased along the saturated lateral flow path. Subsurface, translatory flow and equilibrum reactions along vertical infiltration flow paths are the key process that explain the behavior of stormflow chemistry at the EGIL-catchment.Norsk Hydrologisk komite (NHK

Berechnung der Sickerwassermenge unter Wald

This report describes the soil water budget of two beech forests and two clearings in the forest distict of Essen (West Germany). A physical model of water movement in soil was used to calculate monthly sums of the seepage water that leaves the root zone. This information is essential for the evaluation of the ion budgets at these sites. The simple model of water flow through a forest ecosystem is calibrated against measurements of soil water potential over depht and time. The report exemplifies how such models can help to reduce the experimental effort within studies that aim at the water and ion budget of forests.SILVA Økologische Gutachten und Umweltanalytik Gmbh, am Pappelberg 10. D-3401 Ebergøtze

Das Anthropozän - Realität oder akademische Konstruktion?

Der Begriff des Anthropozäns fordert auf zu einer neuen Zusammenarbeit zwischen Natur-, Technik-, Sozial- und Kulturwissenschaften.Das Anthropozän - Realität oder akademische Konstruktion?publishedVersio

Reversibility of acidification: Soils and surface waters

Recent declining levels of acid deposition in both North America and Europe have initiated reversal of acidification and recovery of impacted ecosystems. The reversibility of acidification has also been investigated by means of large-scale experiments with whole ecosystems. Predictive models can account for much of this empirical and experimental data, at least at coarse spatial and temporal scales. Discrepancies between observed and predicted effects are due in part to the increasingly important role of nitrogen in soil and water acidification. "Nitrogen saturation" threatens to offset the incipient recovery due to reductions in SO2 emissions. Possible ecosystem impacts of future climate change add further uncertainty to predictions of long-term acidifications trends

Emergence of Observational Hierarchies in Natural Evolution

The starting point for our work are (models for) forest ecosystems. We seek to integrate two sources of knowledge about such ecosystems: the scientific approach from the viewpoint of an exo-observer (one that is detached from the system and has theoretically unlimited observational capacity) and the management approach for utilization (one that has a common history with the managed system and includes the possibility of an endo-observer). Within the scientific approach, these ecosystems are often regarded as being among the most "complex" systems that can be abstracted as objects, whereas their practical management for human utilization (including interferences of an occasionally entangled endo-observer) sometimes has allowed economically reliable predictions over time scales from years up to a century. Each approach alone seems to be insufficient to solve the theoretical and applied problems of contemporary ecology. Practical experiences on one hand cannot be extrapolated and become i..