Banca de QUALIFICAÇÃO: CARLOS LEANDRO COSTA SILVA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : CARLOS LEANDRO COSTA SILVA
DATE: 21/08/2023
TIME: 15:00
LOCAL: Google Meet
TITLE:

Impacts of Climate Change on Plant Invasion in the Caatinga: Future Projections and Risks

KEY WORDS:

Caatinga, Exotic invasive plants, Climate change, Modeling.

PAGES: 50
BIG AREA: Outra
AREA: Ciências Ambientais
SUMMARY:

The increase in the number of exotic invasive plant species in biomes, even in the face of limiting factors such as climate change, highlights the remarkable adaptive capacity of these organisms. It's common that when analyzing the invasion process, the focus is on the individual advancement of each plant, neglecting the possibility of multiple individuals invading the ecosystem. For this reason, the distribution of 20 exotic invasive plant species with high invasion potential in the Caatinga biome was designed in response to climate change. To achieve this, the MaxEnt algorithm was used to model their potential distribution in two scenarios: an optimistic one (IPSL-CM6A-LR_ssp1-2.6) and a pessimistic one (IPSL-CM6A-LR_ssp5-8.5), up to the year 2100. In the modeling process, 22 bioclimatic variables were selected, identified through Principal Component Analysis (PCA), those that contribute the most to the modeling. Then, a Species Distribution Model (SDM) was created for each plant, and from these individual models, a single consensus SDM was generated that represents the average invasion pattern of the 20 invasive species in each scenario. Additionally, the species were grouped into herbaceous plants, shrubs, trees, and grasses to evaluate the potential distribution of each life form according to the SDMs. The validation of the modeling results was performed through the Area Under the Curve (AUC), where the closer the value is to 1, the higher the reliability of the projections created. Principal Component Analysis (PCA) identified "Monthly Total Precipitation" as the most important variable for the modeling. The consensus models obtained AUCs above 0.7, indicating positive significance and departing from the randomness of the SDMs. The projections show that by the end of the 21st century, the invaded regions in the Caatinga will remain the same, covering areas in the states of Ceará, Rio Grande do Norte, Paraíba, Pernambuco, Alagoas, and Sergipe. The areas highly suitable for invasions in these states can reach up to 15 km² by 2040, but with a considerable decrease from that period, reaching around 3 km² by the end of the century in the optimistic scenario and 4 km² in the pessimistic one. The years between 2061 and 2080 might be those with the highest amount of suitable areas for invasion across the four life forms, even though the increase in km² of these areas isn't as pronounced. Grasses and herbaceous plants were the only ones that didn't show significant losses in km² of habitat for invasion, even in the pessimistic scenario. Cyperus rotundus L., Impatiens walleriana Hook. f., Dodonaeaviscosa Jacq., Acacia mearnsiiDe Wild., Syzygiumcumini(L.) Skeels., Uruchloadecumbes Stapf, and Megathyrsus maximus Jacq. are possibly the species with the highest chances of invading habitats over the years in the two studied scenarios. The loss of suitable areas is as concerning as the gain, as it raises questions about the survival of native species in the Caatinga in the face of climate change, given that even robust organisms like exotic invasives can suffer negative impacts. Therefore, it is hoped that the projections of this article will contribute to the formulation of new studies and projects aimed at controlling and managing exotic invasive species in sensitive biomes like the Caatinga.

COMMITTEE MEMBERS:
Presidente - 1759367 - REBECCA LUNA LUCENA
Interna - ***.847.484-** - MARCELLA ARAÚJO DO AMARAL CARNEIRO - UFRN
Externo ao Programa - 1280761 - CRISTIANO PRESTRELO DE OLIVEIRA - UFRN