Red List Index and Functional Diversity for Finnish Vascular Plants

• Main Author: Rikberg, Jon
• Other Authors: Helsingin yliopisto, Bio- ja ympäristötieteellinen tiedekunta, Bio- ja ympäristötieteellinen tiedekunta, University of Helsinki, Faculty of Biological and Environmental Sciences, Faculty of Biological and Environmental Sciences, Helsingfors universitet, Bio- och miljövetenskapliga fakulteten, Bio- och miljövetenskapliga fakulteten
• Format: Master Thesis
• Language: English
• Published: Helsingin yliopisto 2018
• Subjects: rödlisteindex; kärlväxter; Finland; hotbedömning; utrotningsrisk; funktionell diversitet; taxonomisk diversitet; red list index; vascular plants; threat assessment; extinction risk; functional diversity; taxonomic diversity; none; kasvibiologia; Plant Biology; växtbiologi; Leda; Northern Finland
• Online Access: http://hdl.handle.net/10138/277640

The Red List Index (RLI) has widely been recognized as a useful tool in keeping track of extinction risk trends of large taxa. The RLI is an index based on IUCN’s threat categories. Functional diversity (FD) is a way of measuring biodiversity that describes species´ traits that are linked to species´ ecological roles. In this work I have mapped the spatial distribution of the RLI and functional diversity for Finnish vascular plants. I first produced species distribution models (SDMs) for all 1194 species of vascular plants in the Finnish Red List 2010 based on records from the Kastikka and Hertta databases and environmental data. A functional tree incorporating 971 of those species was calculated using seven functional traits. The traits that I used were life form, maximum plant height, seed mass, seedbank longevity, life span, specific leaf area (SLA), and leaf dry matter content (LDMC). The trait data was gained from the databases Leda and TRY. Based on the SDMs, the functional tree, and the Finnish Red List, taxonomic and functional diversity and RLI were mapped for the whole of Finland using 10 x 10 km cells. This was the first time FD and RLI were mapped for vascular plant species across Finland. Null models were used to compare observed values with the ones expected if species (and consequently traits) distributions were random accross the country. Taxonomic diversity (TD) was higher than expected in southern Finland and lowest in northern Finland, suggesting a strong latitudinal gradient. TD correlated with the same environmental variables as FD. Thus, it is likely that both TD and FD are dirven by the same environmental variables. FD was higher than expected in southern and western Finland and lower in the northern and eastern parts of the country. A strong environmental filtering in the north might cause low FD by limiting species´ distributions within many clades and favouring species with similar traits that allow them to survive in extreme conditions. In southern Finland, competitive exclusion might ...