Monitoring data of natural and man-made semi-natural meadows in and around Oslo, Norway 2018-2021

Study Extent

Data was sampled in a number of meadows in the municipalities Oslo, Bærum and Lillestrøm in Norway. The first dataset was collected in 2018, then in 2019. From 2021 the monitoring of three meadows located at Lysaker in Oslo, Norway was added. Monitoring of the tree meadows at Lysaker is planned biannually from 2021 to 2029.

Sampling

Plant species at each site were surveyed based on their presence or absence within a sample plot. A sample plot consisted of a wooden frame measuring 0.5 x 0.5m on the inside edge laid onto the ground, and each site was sampled 14 times on the same day, once in the beginning of summer (June – July) and once toward the end of summer (August – September) for a total of 28 times. The plots were distributed semi-evenly across any given site by counting steps between plots (number dependent on the size of the site), then tossing the wooden frame blindly in order to avoid selectively including plant specimens. Human-related features such as paths and trampled regions were actively avoided, while bare rock was not. Because plots were not marked it’s possible that some plants were resampled in the second round of 14 surveys, but due to the relatively small area sampled compared to site size for all but the smallest sites this was not considered to be a significant source of error. Each angiosperm plant emerging from the ground within the frame’s area was identified to species if possible, and in cases where species was uncertain, a botanist was consulted. Grasses (Poaceae) were initially included in the survey but later excluded since some sites were mown partway through the season, removing the identifying organs of most grass species. Each species (or genus) was recorded a maximum of once per plot. In this published data set, all species recorded to species level are included. Species not identified to species level is not included. As mosses, liches and graminoids was not recorded consistently between sites or years, sites are not directly comparable unless these species groups are removed from the data set prior to anlysis. The study area and methods for the 2018 survey are described in detail in this master's thesis from 2018: https://nmbu.brage.unit.no/nmbu-xmlui/handle/11250/2605429

Method steps

1. - Survey of plant species, from a number of meadows, within a sample plot of 0.5x0.5 m. - All angiosperms within the plot was recorded to species. - Meadows was surveyed twice per sampling year (June-July) and (August-September). - Survey was performed in 2018, 2019 and 2021. - Further survey of three meadows are planned for 2023, 2025, 2027 and 2029.

Vascular plants, mosses, liches.

1. plantae
   rank: kingdom
2. fungi
   rank: kingdom

Data from the municipalities Oslo, Bærum and Lillestrøm in Norway.