Thermal Influence of Volcanic Tephra on Maximum Soil Temperatures: Geoecological Implications for Germination and Distribution of Argyroxiphium sandwicense (Haleakalā, Maui, Hawai’i)

Francisco Luis Pérez ()
Additional contact information
Francisco Luis Pérez: Department of Geography and the Environment, University of Texas, Austin, TX 78712-1098, USA

Geographies, 2025, vol. 5, issue 1, 1-52

Abstract: Mid-day maximum soil temperatures were measured at 10 study plots during different hot summer days in Haleakalā Crater, Maui, with thermocouple thermometers on five adjacent microsite types: bare surface soils, soils under black tephra, soils under reddish tephra, soils shaded by silverswords, and soils under plant litter. The main tephra morphologies and geomorphic environments, as well as their geoecological association with silversword rosettes ( Argyroxiphium sandwicense ), were also assessed; silversword density was substantially greater on reddish tephra-covered areas than under black tephra fragments. Silversword seeds are extremely sensitive to high temperatures and fail to germinate after a short exposure to soil temperatures ≥35 °C. Thermal data sets were statistically compared with parallel box plots; the ability of various microsites to provide safe sites for silversword growth was also assessed. Bare soils and black tephra reached the highest median temperatures, up to 48.7 °C and 40.3 °C, respectively; reddish tephra remained much cooler, with all median temperatures ≤30.8 °C. Rosette-shaded soils and soils under silversword litter were the coolest, with temperatures below 18.7 °C and 18.5 °C, respectively. Temperatures in all microsites, except those under black tephra, were significantly lower ( p < 0.0001) than on contiguous bare ground. It was concluded that reddish tephra provides the ideal conditions for silversword regeneration.

Keywords: albedo; box plots; nurse boulders; nurse plants; nurse rocks; rosette plants; soil color; volcanic tephra (search for similar items in EconPapers)
JEL-codes: Q1 Q15 Q5 Q53 Q54 Q56 Q57 (search for similar items in EconPapers)
Date: 2025
References: View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/2673-7086/5/1/13/pdf (application/pdf)
https://www.mdpi.com/2673-7086/5/1/13/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jgeogr:v:5:y:2025:i:1:p:13-:d:1609677

Access Statistics for this article

Geographies is currently edited by Ms. Fannie Xu

More articles in Geographies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().