Banca de DEFESA: Isabela Bezerra de Castro

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : Isabela Bezerra de Castro
DATE: 08/12/2023
TIME: 14:30
LOCAL: Plataforma Zoom
TITLE:

"Effect of soil nutrient addition on the diversity and functional structure of Cerrado woody species".

KEY WORDS:

Nutrient use. Leaf economics spectrum. Foliar traits. Biogeochemistry in tropical ecosystems.

PAGES: 84
BIG AREA: Ciências Biológicas
AREA: Ecologia
SUMMARY:

Nutrient addition in dystrophic environments alters various aspects of plant communities and consequently the functioning of ecosystems. In the Brazilian savannah known as the Cerrado, a hotspot for biodiversity conservation, woody plants are adapted to nutrient-poor soils and have a conservative strategy for using resources. Taxonomic and functional responses of tropical plants to the addition of nutrients to the soil are poorly studied despite the rapid changes observed in these ecosystems. To understand the response of the plant community to the addition of nutrients, we conducted a study in a long-term fertilization experiment, in which N, P, NP and liming were applied to the soil, with the last application in 2018. We hypothesized that: I) there is a change in species composition and decreased taxonomic diversity in the nutrient addition treatments, especially in the NP treatment; II) soil nutrient addition alters functional richness, equitability and divergence, decreasing functional diversity in the treatments, especially in NP and liming; III) the variation in functional traits will be explained mainly by the change in species, but intraspecific trait variation will be significant; IV) the addition of nutrients to the soil promotes greater intraspecific trait variation in nutritional traits than morphological ones; V) the removal of nutritional limitation in Cerrado soils alters the strategy of woody species and VI) there is greater variation in traits in the treatment with the addition of nutrients than in liming. To test these hypotheses, a floristic inventory of woody species was carried out and traitsrelated to the use of nutritional resources were collected from 676 individuals of 18 dominant species in the area, representing 75% of the relative abundance in each treatment. A change in species composition and a decrease in taxonomic diversity was observed in all treatments, especially in NP. Functional diversity was highest in the N treatment, followed by NP, control, P and finally liming, with the lowest functional diversity value. The variation in traits was explained mainly by species composition, followed by the intraspecific component of variation. There was a change from a conservative to an acquisitive strategy in Qualea parviflora, Rourea induta and Roupala montana in the treatment with combined N and P fertilization, while Dalbergia miscolobium and Rourea induta showed a tendency towards conservative changes in the P treatment. Competitive interactions and a reduction in fitness explain the changes in species composition, with some species benefiting from the addition of nutrients. Differences in functional richness, equitability and divergence between treatments describe the changes in functional diversity. The results found here show that the addition of nutrients to the soil affects several aspects of woody plant communities, with residual effects being found even after five years without new fertilizations.

COMMITTEE MEMBERS:
Interna - 5192951 - CASSIA BEATRIZ RODRIGUES MUNHOZ
Interna - 404908 - HELOISA SINATORA MIRANDA
Externa à Instituição - LUISA MAFALDA GIGANTE RODRIGUES CARVALHEIRO - UFG
Presidente - 1122706 - MERCEDES MARIA DA CUNHA BUSTAMANTE