Seasonal climate variations drive decoupling between the duration and amount of xylem growth along a hydrothermal gradient in the southern Altai Mountains

Arid and semiarid forests are vulnerable to climate change. Whether rising temperatures would increase wood production by extending the growing season in these relatively dry forests remains unclear. 
Here, we document a decoupling of duration versus the amount of wood production. Despite the prolonged duration of xylem cell production induced by warming, we did not observe a consistent increase in the amount of xylem growth, based on a two-year (2018-2019) monitoring of wood formation in Siberian spruce (Picea obovata Ledeb.) along a natural hydrothermal gradient in the southern Altai Mountains of central Asia. 
The duration of cell production ranged from 43 to 93 days, with the total number of xylem cells between 37 and 185. Notably, the warmest Altai low-altitude site (AL) had the longest duration (82.6 ± 13.3 days) but the lowest number of xylem cells (63.88 ± 15.6 cells) in 2018, indicating a decoupling between growing season length and xylem growth. However, this decoupl..., , # Seasonal climate variations drive decoupling between the duration and amount of xylem growth along a hydrothermal gradient in the southern Altai Mountains

Dataset DOI: [10.5061/dryad.np5hqc05j](10.5061/dryad.np5hqc05j)

## Description of the data and file structure

### Files and variables

#### File: growth\_seasonal\_climate.csv

**Description:** seasonal climates and xylem cell production

##### Variables

* site: site code
* year: study year
* Tree: Tree ID
* RCN.mean: the final total number of xylem cells produced by the end of the growing season (dimensionless count)
* bE: beginning timing of cell enlargement (expressed as the day of the year)
* cE: cessation timing of cell enlargement (expressed as the day of the year)
* dE: duration of cell enlargement (days)
* r90: mean cell production rate (cells/day)
* Tmean_spring: spring temperature (degree Celsius)
* P_spring: spring precipitation (mm)
* Tmean_summer: summer temperature (degree Celsius)
* P_summer: summer precipitation ...,