The article presents an analysis of cultural energy consumption and structure in the same area (1007 square kilometres) in three years: 1417, 1570 and 1760. In the first period the area under consideration was part of the Tuchola commandry, and the other two it comprised the so called ‘Zabory demesne' (klucz zaborski) in the starosty of Tuchola. Energy consumption was estimated on the basis of the historical data on the age, sex and professional structure of the population, the number of households, farms, workshops and facilities, as well as the data on the acquisition of energy and the energy value of the carriers applied. The consumption of cultural energy in the area was estimated at 62.37 GJ in 1417, 115.02 GJ in 1570, and 280.56 GJ in 1767. In all the periods the largest proportion of energy was obtained from firewood: 95.55% in 1417, 96.66% in 1570 and 97.08% n 1767. Of the three remaining sources, that is waterpower, human and animal labour, the most important was the last one, comprising respectively 2.75%, 1.74% and 1.53%. The study also estimates the decrease of primary production and biomass in the Zabory demesne at the end of the 18th c as a result of economic activity. The influence of economic processes on the structure of landscape was estimated by applying the GIS technology to the analysis of historical cartographic sources, taking into consideration the ratios of primary production and biomass in different types of ecosystems established by ecologists as a part of the International Biological Programme. The decrease of primary production was estimated at 24.11%, while the loss of biomass at 55.04%. To compare, the respective ratios in the ground demesne of the starosty of Tuchola were 31.00% and 64.74%. The analysis of the whole demesne was supplemented with an analysis of a single tar-maker settlement, Asmus, founded in 1686. For this unit within the demesne an energy balance was calculated. The energy value of the mass imported to the settlement was estimated at 10.08 GJ km-2 year-1. The import was mostly food, textiles, tools and everyday utensils. The export of energy from the system was estimated at 721.2 GJ year-1. The ratio of export to import was E/I = 71.55, while calculated as I/E = 0.014. The analysis of the Asmus settlement has also resulted in compiling an ecogram and an energy flow chart, showing the major groups of energy transformers, such as humans, plants, livestock and machines, as well as their interrelation with the environment in terms of the import and export of energy. Another subject of analysis was the structure of landscape around the studied settlement in relation to its cultural metabolism. The analysis has shown that despite the relatively low energy consumption, comparable to other economic units and to the later periods in the history of Asmus, the settlement influenced the natural subsystem to a considerable extent, due to extensive felling. Cartographic materials indicate that the settlement and its surroundings were largely deforested. The final part of the article discusses other methods used in ecoenergetics to estimate the degree of implementing the principles of sustainable development in an economy. The methods include: the measurement of biophysical capital and negentropy cost, the estimation of embodied solar energy (or emergy) and the estimation of the ratio of sustainable development. The article gives the initial calculations of those ratios for some subsystems of the Zabory demesne. In conclusion it is stated that all the energy indexes considered can be applied in monitoring the past, present and future condition of the area under examination, while data gathered by historians and ecologists can be used more effectively through modelling the long-term development of the Zabory region.
Financed by the National Centre for Research and Development under grant No. SP/I/1/77065/10 by the strategic scientific research and experimental development program:
SYNAT - “Interdisciplinary System for Interactive Scientific and Scientific-Technical Information”.