Drought effects in Mediterranean forests are not alleviated by diversity-driven water source partitioning

Tree species diversity in forest ecosystems could reduce their vulnerability to extreme droughts through improved microclimate and belowground water source partitioning driven by contrasting species-specific water use patterns. However, little is known about the seasonal dynamics of belowground water uptake that determine whether diversity positively or negatively impacts tree carbon assimilation and water exchange.
Using a network of 30 permanent plots in Mediterranean forests with increasing tree species diversity (from monospecific to four-species mixtures), we examined the seasonal patterns of in-situ aboveground carbon and water relations and belowground water sources on 265 trees from four pine and oak species over two years using hydraulic and stable isotope approaches.
We found that increasing species diversity in broadleaf and conifer mixtures induced strong soil water source partitioning between oak and pine species. As conditions became drier during the summer in mixed stands..., Site description
The study was conducted in Mediterranean forests in the Alto Tajo natural park (Guadalajara, Castilla La Mancha, 40.66°N, 02.27°W) in central Spain, where 30 plots (30m x 30m) within a 20 km2 area were selected from the FunDivEUROPE Exploratory Platform (Fig. S1, Baeten et al., 2013). To assess the effect of tree diversity, the plots were established in 2011 in non-managed mature even-aged (i.e., more than 50 years) forests with limited variation in altitude (i.e., from 980 to 1300 m a.s.l.), topography, soil type, and density (see Table S1 and Baeten et al. (2013) for more details on plot selection). The soils in all plots were shallow (from 20 to 40 cm) calcic cambisol soils (FAO/UNESCO soil classification) on a cracked limestone bedrock but with plant roots that may extend down to several meters through the fractured bedrock (Peñuelas & Filella, 2003). This area has a continental Mediterranean climate with hot and dry summers and cold winters. The long-term annua..., , # Data from: Drought effects in Mediterranean forests are not alleviated by diversity-driven water source partitioning

[https://doi.org/10.5061/dryad.1vhhmgr35](https://doi.org/10.5061/dryad.1vhhmgr35)

## Description of the data and file structure

Description for the metadata in the file \"Data_soil\"

| Column | Entry | Value | Unit | Explanation | Remark |
| :----- | :--------- | :---- | :--- | :-------------------------------------------------------------------------------- | :---------------------------------------------------------- |
| A | Year | 2 | | Year (2021; 2022) | |
| B | Date | 6 | | Date of the measuring campaign (format: Year-Month) | ...