ISSN:
1573-5052
Keywords:
Aster tripolium
;
Environmental disturbances
;
Halimione portulacoides
;
Population dynamies
;
Puceinellia maritima
;
Salt-marsh vegetation
;
Species strategies
;
Suaeda maritima
;
Succession
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary Studies on sample plots inHalimione portulacoides communities show that environmental disturbances, either natural or induced by man, start a sequence of partly overlapping density maxima inSuaeda maritima, Aster tripolium andPuccinellia maritima successively, before the originalHalimione community totally recovers. When succession time before recovering is long enough, there are tendencies in redundancy of this sequence stressing the unilinear character of the succession. Minor environmental impacts induce a longer time-lag period of theSuaeda density maximum, suggesting threshold values of these impacts for the species to maintain minimal population densities or to become locally extinct. This sequence of interim species starting after an environmental disturbance, suggests also a gradient character in various biological attributes, for instance in life-time, propagation, nutrient and genetic plasticity strategies. The mechanism described can therefore be interpreted as a complex of mostly well-adapted and well-integrated inherent species strategies capable of absorbing environmental shocks. It is suggested that in the salt-marsh ccosystem the pattern of spatial variation in densities and that of temporal variation in fluctuations of the three species populations under natural conditions reflect corresponding patterns of environmental disturbances in the vegetation taking into account a timelag associated with the magnitude of the impact concerned.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01324769
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