Landscape composition and climatic parameters significant in the spread of an invasive species (Pine wood Nematode)

Dissertação para obtenção do Grau de Mestre em Engenharia do Ambiente

Studies show that the number of biological invasions has increased. The spread of species from their native range to other places is directly related to the increase in transport and movement of people and their goods. The Pine Wood Nematode (Bursaphelenchus xylophilus) (PWN), the causal agent of the pine wilt disease, is an example of this problem, originated from North America, has become a serious pest on Eurasia. This dissertation aims to understand if environmental factors are determining tree mortality in an area where the PWN has been confirmed since 2009. The study area is located in the centreal part of Portugal, a complex area regarding the topography and soil making it also complex concerning climatic and ecological conditions, providing a good study case on the possible interaction between a biological invasion and local environmental conditions. In order to evaluate the study area several of environmental parameters were determined, and analyzed in GIS. Additionally it was determined the proportion of recently dead trees in randomly selected pine forests within the study area. The Binary logistic model showed that temperature in the warm trimester was the only parameter that better predicted the mortality. Climate change models predict an increase in the temperature in the future, thus indicating that the susceptability of Pinus pinaster to the PWN will increase.

Portuguese Science Foundation - project “Developing an adaptive management system for predicting and mitigating damage caused the pine wilt nematode Bursaphelenchus xylophilus (Nematoda: Aphelenchoididae) in Portugal” refª PTDC/AGR-CFL/098869/2008