Macro and micro environmental factors predict the location and movement of the treeline in the subalpine and alpine regions. In many subalpine regions globally, trees have, in the past century, recruited upslope as a result of climate change. In the Wasatch Plateau of central Utah, however, this has not shown to be true in spite of warming temperatures. Descriptions of the factors of subalpine trees movement are often limited by the availability of proper sensor networks that utilize necessary types of standards and fine-scale measurements. Understanding the movement of the treeline with climate change will require large datasets and precise measurements of the meso environment of the treeline in the subalpine region. The cost of sensor networks is decreasing, raising problems with data management and analysis. Here, we report on differences in the meso environment at treeline on the Wasatch Plateau of Utah, comparing differences in alpine meadow and tree island soil and atmospheric conditions on leeward, summit, and windward locations. We process and analyze two years of 15-minute temporal data with depth across a 1 kilometer transect over the summit of the Plateau.
Results/Conclusions
We found there to be significant differences in snowmelt timing, summer dry down, and infiltration during summer storms between tree islands and meadows at the varying locations. Likewise, there was much higher water availability but lower soil temperatures in tree islands states. Surprisingly we saw large differences spatially from windward to leeward side of the plateau, with the lowest soil moisture at the summit and highest at the windward location. We predict that major mid-summer soil deficits may control the movement of trees into meadows. We also found strong indicators that the Wasatch Plateau may be a water-driven treeline as much as a thermal treeline. In addition, we developed a detailed eco-informatic approach to managing, cleaning, and analyzing our high resolution data.