Evidence for antagonistic effects of climate change and exotic pathogens on regeneration of Mediterranean forests

Understanding the interactive effects of global change drivers on tree demography is fundamental for realistic predictions of future forest dynamics. Multiple studies have shown increasing drought and exotic pathogens to severely threaten forest persistence by increasing mortality and decreasing growth of adult trees. However, much less is known about their effects on regeneration, and how they might affect seedling performance in additive and non-additive (synergistic or antagonistic) ways.
Here we aimed to fill this gap by experimentally exploring the effects of increasing drought and soil-borne pathogens on tree regeneration in two types of mixed oak forests (Quercus suber-Q. canariensis and Q. suber-Olea europaea) invaded by the exotic soil-borne oomycete Phytophthora cinnamomi, one of the most aggressive plant pathogens on earth. We conducted a seed-sowing experiment with oomycete-specific fungicide taking advantage of rainfall exclusion infrastructures that excluded 30% of the an..., We conducted a sowing experiment using seeds of the two dominant species at each forest type: Q. suber and Q. canariensis in the closed forest, and Q. suber and O. europaea in the open woodland. In December 2016, two 25 × 25 cm sowing quadrats (“Control” and “Fungicide”) were established under each of the 86 study trees. At each quadrat we established 16 sowing points. In the closed forest, one acorn of Q. canariensis or Q. suber was sown per point, making a total of 688 seeds per species (8 seeds × 2 treatments × 43 trees). In the open woodland, one acorn of Q. suber was also sown per point (n = 688 acorns). However, we sowed a higher number of O. europaea seeds (17 seeds per point, 11696 seeds in total) to compensate for the low germination rate of the species. Seeds in the fungicide quadrats were treated monthly with an oomycete-specific fungicide (Armetil 25 WP, 25% metalaxyl), whereas Control seedlings were treated with an identical volume of water. Seedling emergence, survival, an..., , # Evidence for antagonistic effects of climate change and exotic pathogens on regeneration of Mediterranean forests

[https://doi.org/10.5061/dryad.wstqjq2t3](https://doi.org/10.5061/dryad.wstqjq2t3)

This dataset contains data of emergence, survival and growth of seeds of *Quercus sub*er, *Quercus canariensi*s and *Olea europaea* in experimental rainfall exclusions located in Mediterranean forests of Southern Spain.

## Description of the data and file structure

The Excel file includes information about:

* **site**: factorial variable with two levels (Gamir or Marrufo)
* **block**: factorial variable with three levels to take into account the spatial nested design of the experiment (1, 2 or 3)
* **n\_tree**: factorial variable representing each of the target trees (43 per site)
* **quadrat**: factorial variable representing each of the sowing quadrats in the experiment (86 per site, 43 with fungicide and 43 without fungicide).
* **seed\_weight**: weight (in grams) of *Quercus suber* ...