Banca de DEFESA: MARYANA VITAL COSTA DE OLIVEIRA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : MARYANA VITAL COSTA DE OLIVEIRA
DATE: 28/02/2023
TIME: 09:00
LOCAL: https://meet.google.com/hdq-qitw-qtg
TITLE:

PHYTOSOCIOLOGY, BIOMASS AND FIXED N CONTRIBUTION IN FORAGE USE AREAS IN THE CAATINGA BIOME

.

KEY WORDS:

phytomass, isotopes, nodulating legumes, symbiotic fixation, livestock.

PAGES: 68
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SPECIALTY: Microbiologia e Bioquímica do Solo
SUMMARY:

In the semi-arid regions of Brazil, the main native vegetation, the Caatinga, is
constantly involved in the process of changing land use for the inclusion of
extensive livestock activity. The pre-existing plant biomass of this biome is lost,
together with the constituent nutrients of the soil stock that could integrate the
natural cycling. An element that is largely connected with the use of this land and the
cycling is nitrogen. The objective was to estimate the impact of livestock use on the input of
fixed nitrogen in nodulating legumes in areas with different land cover
plants in the Caatinga Biome. The evaluations were carried out in plots that make up
the first network of permanent plots for ecological studies in areas of livestock use
in the Caatinga Biome (PERENE), in the municipalities of Arcoverde and Sertânia in Pernambuco.
8 plots were delimited, 4 plots for each municipality, with 20 x 20 m,
totaling a sample area of 400 m² per plot, divided between two coverages
vegetation (open and dense caatingas) and two managements (with and without excluding animals).
Within the plots, all plants that presented stem diameter at breast height
greater than or equal to 3 cm had their circumferences measured. being transformed into
basal area (AB) and posteriorly in diameter at breast height (DBH). were also
determined the absolute basal areas and the absolute and relative densities, to
floristic and phytosociological survey. Estimates of fixed nitrogen
symbiotically in tree legumes and in herbaceous legumes were made the
from the technique of natural abundance of 15N and estimates of biomass by equations
allometric measurements used for Caatinga species. The shrub-tree flora of these eight
plots in the Caatinga is represented by 39 species distributed among 13 families
botanicals. Fabaceae represents 76% of the identified species. The parameters
phytosociological data and leaf biomass and calculated totals, showed great
variation. Species with potential for fixation showed a proportion of derived N
of the atmosphere (%Ndda< 68%) and the fixed N input varied between 0.67 and 9.96 kg ha-1
year 1
.

COMMITTEE MEMBERS:
Presidente - ***.055.504-** - ANA DOLORES SANTIAGO DE FREITAS - UFRPE
Externa à Instituição - EDILANDIA FARIAS DANTAS - UFPE
Externo à Instituição - PLÍNIO BARBOSA DE CAMARGO - USP