Steppe islands in a sea of fields (southern Ukraine)

Study Extent

We conducted the field sampling in the Kherson region, southern Ukraine (46.63–47.36° N, 32.29–34.32°E; 39–96 m a.s.l.). The climate is continental, with a mean annual temperature of 9–10°C and a mean annual precipitation of 415–450 mm (Fick and Hijmans, 2017). The landscapes are dominated by vast, slightly undulating plains. Loess is the most common geological surface formation, reaching a thickness of several tens of meters (Boiko, 1998). The study area belongs to the West Pontic grass (true) steppe zone (Bohn et al., 2004). The natural vegetation is dominated by tussock grasses, but is also relatively rich in forbs adapted to summer drought as well as spring therophytes and geophytes.

Sampling

In the years 2012–2016, we recorded the vascular plant flora of 86 kurgans that were in a relatively good state (i.e., they still contained at least five steppe plant species and were not flattened by illegal excavations or agricultural activities). They were selected to represent a wide range in size and degree of isolation from larger steppe areas. We visited each kurgan at least twice during a season to ensure completeness of the species lists. For the further analyses, we added published data from 26 kurgans located in the same region and studied with similar methods (Sudnik-Wójcikowska and Moysiyenko, 2006), resulting in 112 kurgans in the final dataset.

Quality Control

The identification of vascular plant species was held with morphological methods at the field and in the Kherson State University Laboratory of Plant Ecology and Environmental Protection. Coordinates of records were checked using Google Earth service and GIS. Data cleaning using OpenRefine.

Method steps

1. Field sampling
2. Recording and identification of vascular plants
3. Completing of cheklist of vascular plant
4. Data post-processing according to the Darwin Core standards
5. Data checking and cleaning in OpenRefine

The dataset includes 383 taxa of vascular plants (determined to 356 species and 27 to genus level).

1. Plantae
   rank: kingdom
2. Tracheophyta
   rank: phylum
3. Gnetopsida
   rank: class
4. Liliopsida
   rank: class
5. Magnoliopsida
   rank: class

Southern Ukraine.