A Method for the Analysis of Temporal Changes in Vegetation Pattern at the Landscape Level

Schwabe, A.

A new approach to study temporary changes in small landscape units is proposed, based on vegetation-complex releves (sigma releves). The method is introduced using extensively grazed or abandoned heathland and Nardus-sward landscapes in the Black Forest as examples. Thirty-six sigma releves of the years 1979-80 are compared with those of 1989-90. Each of the compared plot areas covers on the average 2-4 hectares, and has a diversity of about 20 different vegetation types. The vegetation complex releves can be ordered to 3 different types which characterize landscape ecological zones dependant on former rural management.As a result of the comparison 2 main developments which have a spatial differentiation in the Black Forest are confirmed and documentated: 1. Changes of the inventory of vegetation types caused by abandoness. 2. Changes of the inventory of vegetation types caused by fertilizer influence.A serious decline can be regarded concerning indicator communities which have no or nearly no fertilizer influence. This decline is proved statistically.The method gives an opportunity for monitoring a definable matrix of vegetation types (the actual 'status quo'). If it is compared with a vegetation mapping the proposed method needs relatively short time and includes vegetation units as e.g. small 'fringe' communities and vegetation of small gaps which regularly cannot be mapped and often have an indicator value.The application purposes of the method are e.g. monitoring for nature conservation purposes or status quo investigations, and monitoring for the 'Environmental Impact Assessment' (EIA).

A Method for the Analysis of Temporal Changes in Vegetation Pattern at the Landscape Level

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