Diameter growth of trees in miombo and acacia woodland in an eroded landscape in NE Tanzania

Diameter increment of trees typical of miombo and acacia woodland was studied during a period of 20 years in Kondoa district, Tanzania. The study was performed in permanent plots in a severely degraded area subjected to considerable restoration efforts. A total of 15 species were selected from a database collected within a project for monitoring the landscape recovery. Growth performance of African woodland species was searched for in the literature for comparison, and a comprehensive list of citations was compiled. We found growth to fall within the range reported in earlier studies, although growth varied both between and within species. There are reports that the radial increments of trees are unimodal over their lifespan, but we found no clear support. In several species, the annual growth increased with stem diameter. Growth during the rainy ENSO year 1997/98 was pairwise compared with the preceding two years and was found to be significantly higher during the wet year, pointing to soil water as a limiting factor. We conclude that free development is an alternative to tree planting on marginal land

Pollen analysis and 14C dating in outlining vegetation history of the primeval forest Fiby urskog, south Sweden

The data file is the raw data collected in Fiby urskog, south Sweden in order to perform a paleoecological study, covering ca 7000 years, using pollen analysis, including spores, charcoal fragments and mineral particles from a small wetland basin. 14C dating, diatom analysis and shore displacement data aided in dating the vegetation succession. Indicators of human impact and other disturbances, during the last ca 1000 years, are given particular attention as well as Picea immigration. Pollen was extracted from the sediment with a Russian peat corer (diameter 5 cm) every 2.5 cm down to ca 100 cm. Standard acetolysis method was used to extract pollen and spores. Treatment with hydrofluoric acid was performed on the lowermost part of the sediment to separate the large number of mineral particles.Materialet avser rådata som legat till grund för en pollenstudie vars syfte är att beskriva vegetationshistorien i Fiby urskog, Uppland, de senaste ca 7000 åren. En ca 100 cm sedimentpropp togs i en central våtmark. Tonvikt ligger på de senaste ca 1000 åren där granens invandring och eventuell kulturpåverkan betonas särskilt. 14C-analys har använts vid åldersbestämning liksom landhöjningsdata, diatomanalys och stratigrafi. Se engelska katalogsidan för mer information: https://snd.gu.se/en/catalogue/study/SND112

Diameter growth of trees in miombo and acacia woodland in an eroded landscape in NE Tanzania

Diameter increment of trees typical of miombo and acacia woodland was studied during a period of 20 years in Kondoa district, Tanzania. The study was performed in permanent plots in a severely degraded area subjected to considerable restoration efforts. A total of 15 species were selected from a database collected within a project for monitoring the landscape recovery. Growth performance of African woodland species was searched for in the literature for comparison, and a comprehensive list of citations was compiled. We found growth to fall within the range reported in earlier studies, although growth varied both between and within species. There are reports that the radial increments of trees are unimodal over their lifespan, but we found no clear support. In several species, the annual growth increased with stem diameter. Growth during the rainy ENSO year 1997/98 was pairwise compared with the preceding two years and was found to be significantly higher during the wet year, pointing to soil water as a limiting factor. We conclude that free development is an alternative to tree planting on marginal land