Data of seedling emergence and seedling survival of Mediterranean high mountain scrublands (Juniperus communis and Berberis hispanic) in Sierra Nevada (Spain). 2017-2020

Sowing desing for restoration of the scrubland in Sierra Nevada


Seeds were sowing in two locations susceptible to recovering the juniper, both on the north and south sides of the Sierra Nevada. The restoration sites are areas within the distribution of high-mountain scrublands, with have suitable conditions to carry out a restoration of junipers.
The ecological conditions are very similar (e.g. exposure, altitude, soil type) to those of the juniper patches. On the northern side ("Acequia de Haza Mesa"), where there are currently juniper trees in relatively good condition, restoration is being carried out with sowings and plantations. On the southern side, where there are no longer any formations of juniper, although there are still scattered junipers, only seed sowing has been done to determine if the current collapse in the regeneration of the juniper tree on the southern slope is fundamentally due to a problem of limitation in the arrival of seeds, as a consequence of the very small number of adult junipers present.

The sowings have been carried out in the following microhabitats: 1) under juniper, 2) under genista, 3) under stone, 4) wet meadow, and 5) in open ground. 150 sowing stations were set up on north face (30 units per microhabitat), and 60 sowing stations on the south side (30 units per microhabitat; only under stone, wet meadow, and open ground microhabitats are present).
In autumn 2016, 3150 filled seeds of Juniperus and 3150 seeds of Berberis hispanica were randomly taken from a sample of bird-dispersed seeds collected near the study site. In each sowing station 15 seeds of each species were homogeneously distributed and sown at 1 cm deep in the soil. Sowing stations were protected against seed predators by a wire cage of 20x30x10 cm and 1 cm mesh.

They sowing stations were monitored 2-3 times a yerar for seedling emergence from spring 2017 to autumn 2020. For each sowing station, soil moisture (in volumetric water content, VWC) was measured along the first 20 cm depth (with a TDR mod 150; Spectrum Technologies, Inc., Plainfield, IL, USA).