A World Without Trees : An Analysis of Global Tree Extinction Rates, Geographical Distribution and Correlation to Socioeconomic Factors

Sammanfattning

Current rates of plant extinction are hundreds of times greater than the estimated background extinction expected without anthropogenic interference. Among all plants, trees species are experiencing one of the highest extinction rates. In 2021, the Global Tree Assessment (GTA) provided long needed assessments of conservational status for all of the world’s known tree species. The aim of this thesis is to utilize the recent assessment of trees to create an overview of global tree extinction with the focus on extinction rates, global distribution of tree extinctions and the correlation to the socioeconomic factors Gross Domestic Product (GDP), GDP per capita, Human Footprint Index (HFI) and agricultural land. All tree species that have been assessed as Extinct (EX), Extinct in the Wild (EW), Critically Endangered (Possibly Extinct) (CR(PE)) and Critically Endangered (Possibly Extinct in the Wild) (CR(PEW)) in Plants of the World Online (POWO), the IUCN Red List (hereafter the Red List) or ThreatSearch is included in this study. The results revealed that the global extinction rate for trees is 17-68 E/MSY which represents a 49-1360 times higher rate than the background extinction rate for plants which is estimated to 0.05-0.35 E/MSY. Global tree extinctions were most prominent in tropical areas surrounding the equator, with island regions experiencing the greatest number of extinctions. GDP and GDP per capita showed weak significant correlation with the distribution of tree extinctions. No significant correlations were found between the distribution of tree extinction and HFI or agricultural land. Suggestions for future research includes developing a more interactive and complex model to examine correlations with socioeconomic factors. The results provide an insight into the current tree extinction patterns and may contribute to the development of effective conservation strategies.