Hot soils and cooler stones: Geoecological influence of volcanic tephra and boulders on soil temperature, and significance for plant distribution in Haleakalā Crater (Maui, Hawai'i)

Plant Organic Matter Really Matters: Pedological Effects of Kūpaoa (Dubautia menziesii) Shrubs in a Volcanic Alpine Area, Maui, Hawai’i

“…Soil textures on bare areas and under shrubs were anticipated to be similar but were examined to ascertain any property differences between paired datasets-e.g., CEC or WRC-were not caused by textural variation [33,35]. Average gravel content was moderate in both sampling locations, but slightly higher under shrubs than in bare areas (Table 3); although K-S or U tests did not show this to be statistically significant, such difference may reflect a preference of kūpaoa for coarser substrates [54,58].…”

“…Freezing may occur any time of the year in the crater, where 121-187 freeze-thaw nightly cycles/year occur at the soil surface [67]. Air maxima peak at ~33 °C, but bare soils frequently exceed 50 °C [68]; I have measured midday highs of 51-56 °C at 2510 m [54], and temperatures ≥60 °C are often reached on dark-colored cinder [69].…”

Clinal variation in drought resistance shapes past population declines and future management of a threatened plant

“…Silverswords appear to be highly adapted to their environment (Robichaux et al. ), and take advantage of favorable microsites such as nurse rocks that improve soil moisture and temperature status and increase seedling survival (Pérez , ). Nevertheless, a ~60% decline in the silversword population size in recent decades has been strongly tied to reduced rainfall, which has coincided with other atmospheric changes such as higher solar radiation and vapor pressure deficit that appeared to result from an upward shift in the incidence of the trade wind inversion (TWI) around 1990 (Krushelnycky et al.…”