Banca de DEFESA: JEANNE RAQUEL DE ANDRADE FRANCO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : JEANNE RAQUEL DE ANDRADE FRANCO
DATE: 28/07/2022
TIME: 14:00
LOCAL: Google Meet
TITLE:

Interactions of Woody and Herbaceous Vegetation: Implications for Ecological Restoration in the Semiarid

KEY WORDS:

Competition; diversity; ecological interactions; facilitation; herbaceous; semiarid.

PAGES: 204
BIG AREA: Ciências Biológicas
AREA: Ecologia
SUMMARY:

The Caatinga biome is one of the largest seasonally dry tropical forests in the world and home to a high diversity of species. Despite this, this biome is susceptible to anthropogenic disturbances and invasion of exotic species, which leads to the loss of native species. Non-tree life forms also contribute to the richness and functioning of the ecosystem, but little is known about the interactions between herbaceous and tree communities. The objective of the first chapter was to evaluate the influence of herbaceous vegetation on the colonization of two native species Anadenanthera colubrina and Astronium urundeuva and an axotic species Leucaena leucocephala in a degraded area. We found that the herbaceous vegetation impairs the growth of the native tree species and has a neutral effect on germination, establishment, and growth of the exotic species. These results raise important questions about restoration methods with native species and management of exotic species in the Caatinga. The objective of the second chapter was to evaluate how tree species richness (control, 1, 2, 4, 8, and 16species) and their compositions affect the richness, percent cover, height, and species composition of the herbaceous vegetation. Tree richness did not affect the richness and percent cover of the herbaceous shrub vegetation, however, there were differences in percent cover by species among the levels of tree richness and limited effect of richness on species composition and vegetation height. Composition interfered with height, percent cover, richness, and composition of herbaceous and shrub vegetation, indicatingthat species composition during the early growth stage of arboreal trees is important for planning restoration methods. The functional attributes of the tree species, such as leaf biomass, leaf area, number of leaves, height, diameter, and number of leaves showed overall negative effects, indicating competition between herbaceous and tree species. The objective of the third chapter was to evaluate how the percent cover, height, and presence of vines of herbaceous and shrub vegetation, including interactions with tree species richness and composition, affect the growth attributes height and diameter at ground height and survival of native tree species during ecological restoration. Negative and positive effects occurred for interactions between herbaceous and tree vegetation depending on tree species composition. The greater height, diameter at ground height (DAS) and survival of tree species were associated with the presence of climbers in the herbaceous- shrub layer. It was found that tree richness and composition alone did not explain tree growth and survival variables. The best selected models include richness and composition acting simultaneously with the herbaceous shrub vegetation variables. According to these results, it is important to consider herbaceous species diversity and tree compositions for effective ecological restoration in the semi-arid region.

COMMITTEE MEMBERS:
Externo à Instituição - RENATO GARCIA RODRIGUES
Externa à Instituição - FERNANDA ANTUNES CARVALHO - UFMG
Presidente - 1677189 - GISLENE MARIA DA SILVA GANADE
Externo à Instituição - JOSÉ ALVES DE SIQUEIRA FILHO
Interna - 3058386 - VANESSA GRAZIELE STAGGEMEIER