ISSN:
1573-5052
Keywords:
Diversity
;
Grassland
;
Niche. Succession
;
Time and Space
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Some diversity and niche amplitude parameters were applied to rangeland pastures of the Central Iberian Peninsula and to their succession stages after the periodical ploughing typical of the traditional management of these areas. Four different slopes within a large area of undulating terrain were selected for the monitoring of succession as they contained the characteristical geomorphological pattern of the area (denudation, transport and accumulation sectors). If we consider the total entropy theorem, H (E.P.)=H(E)+H(P/E), the total entropy of the slope H(E.P) and the entropy of species H(E) increase as succession progresses. As the value of the entropy of the sampling plots conditioned by the species H(P/E) is affected by the number of plots utilized, we employed the expression A=H(P/E)/log2 number of plots, similar to Pielou's index for niche amplitude, W=H(P/E)/H(P). This values decreases with succession, indicating that plant species tend to occupy more definite sectors along the slope. The number of low entropy species H(P/E) i or specialist species, confined to narrow sectors also increases. When computed separately within the different sectors niche amplitude results in small values for the low slope regions (accumulation sector). This effect becomes more pronounced when succession advances.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00118404
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