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Genetic diversity of populations of Brachypodium pinnatum (L.) P. Beauv.: expansive grass in a fragmented landscape

100%

Baba W., Kurowska M., Kompala-Baba A., Wilczek A., Dlugosz J., Szarejko I.

Polish Journal of Ecology

2012

tom 60

nr 1

Brachypodium pinnatum belongs to native grasses which could dramatically decrease the biodiversity of calcareous grasslands, therefore, an examination of the mechanisms of its expansion is of prime importance for their conservation. We studied the genetic structure of 12 subpopulations of the expansive grass B. pinnatum in a heterogeneous landscape with AFLP markers, aiming at determination whether spatial isolation influences the genetic diversity and the population genetic structure of this species. A high level of overall (79%) and within population polymorphic loci (38–44%) were found and 220 different genotypes were distinguished among the 252 samples analysed. No significant population structure nor isolation-bydistance were found, despite their long-time fragmentation history. This confirms that isolation of calcareous grasslands in a landscape cannot prevent the expansion of B. pinnatum grasses because of the high generative dispersal ability. Subsequent quick and extensive clonal growth of this species enables the successful establishment. In most cases mowing or grazing is sufficient to keep this species at a low density within ancient grasslands and to prevent seed and pollen dispersal, but not for restoration of species-rich calcareous grasslands.

Habitat isolation and ecological barriers - the effect on small mammal populations and communities

100%

Kozakiewicz M.

Acta Theriologica

1993

tom 38

nr 1

Various effects of habitat isolation on both population and community processes in small mammals are presented and discussed; numerous examples are given. Both ecological characteristics of a single patch populations (local population level) and ecological processes among habitat patches (metapopulation level) are presented. The connectivity as a parameter which measures inter-patch processes is discussed. The role of habitat barriers as "filters" structuring both populations and communities of small mammals in heterogeneous environments is presented. It is suggested that ecological processes, which are going on among patchily distributed local populations, make the metapopulation a dynamic, functional unit. Movements of individuals between habitat patches are critical to support the existence of species in a patchy, heterogeneous landscapes. For each species the temporal distribution of activity in space reflects the interactions between the temporal dynamics of the species' needs and spatio-temporal dynamics of resources. "Key habitats" play a crucial role for population existence in the dynamics of species' needs and resource supply. The increased mobility of individuals seems to be the best strategy for survival in heterogeneous landscapes. The effect of habitat isolation on genetic divergence within a metapopulation is discussed. It is suggested that the small size of discrete local populations, which temporarily go through a genetic "bottleneck" effect, and occasional migration of individuals between local populations can induce increased, long term genetic variability of the whole metapopulation. It is suggested that landscape heterogeneity and habitat fragmentation affecting the distribution of many species, can also affect interspecific interactions.

Ograniczanie wyników

1 Acta Theriologica

1 Polish Journal of Ecology

1 Baba W.

1 Dlugosz J.

1 Kompala-Baba A.

1 Kozakiewicz M.

1 Kurowska M.

1 Szarejko I.

1 Wilczek A.

1 2012

1 1993

Wyniki wyszukiwania

Genetic diversity of populations of Brachypodium pinnatum (L.) P. Beauv.: expansive grass in a fragmented landscape

Habitat isolation and ecological barriers - the effect on small mammal populations and communities