Hot and dry summer periods can be particularly challenging for plants to endure. Comparing the recent late summer period (8/1 and 9/9) between this versus last year, it is clear conditions at the top of the Waianae range have been very toasty. On average, this year's late summer period has been 2.2C (4F) warmer than last year's (20.3C vs 22.5C, 2018 vs 2019 respectively).
It has also been drier this summer with a third less rain than last year's equivalent period (99.8mm vs 32.5mm, 2018 vs 2019 respectively). Consequently, soil moisture around Caly, and the nearby Cyanea membranacea have hit the lowest values since we began measuring them!
This has resulted in one of the clearest periods of no growth for all monitored plants around here. None of the native plants have grown in diameter in the last few weeks- Caly, Cyanea membranacea, Hoawa, and Ohia.
Of course, year to year weather is bound to vary, but clear drought responses such as those observed now show how native plants can be impacted by changing environmental conditions...