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Universidade Federal Rurale de Pernambuco (2012)

Dinâmica populacional de espécies herbáceas em áreas preservada e antropizada da caatinga

ANDRADE, Juliana Ramos de

Titre : Dinâmica populacional de espécies herbáceas em áreas preservada e antropizada da caatinga.

Auteur : ANDRADE, Juliana Ramos de

Université de soutenance : Universidade Federal Rurale de Pernambuco

Grade : Mestre em Botanica 2012

The different conditions for the establishment of plants such as water availability, light intensity, shading preserved fragments differ from the conditions of anthropogenic areas. In dry environments, the herbaceous cover predominates in the re-colonization of deforested areas, can act as a good group to evaluate the biological impacts of changes in habitat heterogeneity in the process of resilience of dry forests. Therefore, the objective was to evaluate whether the natural regeneration of the herbaceous layer in two microhabitat (parts exposed to direct sunlight and diffuse light) differed between preserved and disturbed areas of scrub and describe how this occurs. The study took place in the semi-arid(caatinga) in preserved and disturbed areas, where they were established 50 plots of 1 m in area, with 25 allocated in microhabitat called direct light and 25 in microhabitat called diffuse light, we assessed the density, height , number of living individuals, number of individuals killed and fruit yield of each species. The herbaceous species were selected for study Delila biflora (Asteraceae), Gomphrena vaga (Amaranthaceae) and Pseudabutilon spicatum (Malvaceae), significant differences between areas and between preserved and anthropogenic microhabitat of direct and diffuse light in terms of density and survival only for first two species. Fruit production was higher in the area preserved for the three species. The study concludes that : 1. the effect of the existence of microhabitat with direct light and diffuse light in areas preserved and anthropogenic depends on the species considered, 2. populations sensitive to variation in light intensity vary in the number of individuals, height and fruit production of plants 3. resilience in areas of anthropogenic semi-arid environments can be characterized by the existence of spatial heterogeneity on the emergence and survival of herbaceous seedlings, suggesting that regeneration areas can occur by anthropogenic spots.

Mots clés  : Ecologia vegetal ; Ervas ; Demografia ; Microsítio ; Agricultura abandonada ; Sombreamento ; Delilia biflora ; Gomphrena vaga ; Pseudabutilon spicatum ; Demography ; Agriculture abandoned ; Microsites ; Shading ; Grass ;


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