BIODIVERSITETS PÅVERKAN PÅ MÄNGDEN ORGANISKT MATERIAL I ALSUMPSKOG: En fallstudie i fyra alsumpskogar på svenska västkusten

Abstract

Globally, coastal ecosystems like mangrove forests, sea grass meadows and salt marshes are well known for their ability to capture and store atmospheric carbon effectively. In Sweden, there is still limited knowledge about local coastal ecosystems with similar functions, with alder swamp forests being an interesting example. Therefore, this study aimed to increase knowledge of the factors that can contribute to the potential carbon sequestering ability of alder swamps. Vegetation data and sediment samples were collected from a total of 37 sampling plots across four alder swamps in Bohuslän on the Swedish west coast. The goal was to determine how plant diversity and the composition of microorganisms influence the amount of organic matter in the sediment. Plant cover and sediment samples were used to calculate diversity indices and the percentage of organic matter, and the relationship between them was analysed using correlation tests. Plant diversity and the amount of organic matter varied greatly both within and between the forests. A negative correlation between these two variables was found, but it was only statistically significant in one of the forests (Havstensfjord). A stronger positive correlation could instead be found between the water ratio and the amount of organic matter in sediment. EcoPlates™ were used to assess how different carbon sources were utilised by microorganism communities in the sediment samples. Multivariate tests revealed that the microbial communities in the different forests were relatively similar in their use of the different carbon sources. The relationship between the composition of microorganisms and the amount of organic matter was mostly positive, although one swamp forest (Finnsbo) showed a negative correlation. Based on this study, it can be concluded that plants, microorganisms and organic matter in alder swamp forests are interconnected, but these relationships are complex and influenced by several factors beyond the scope of this study. Therefore, further research in this area is greatly needed.