Chaparral fern gametophytes experience microclimates with more moisture and more moderate temperatures than fern sporophytes
Presentation Type
Poster
Presentation Type
Submission
Department
Biology
Major
Biology
Abstract
The chaparral shrublands of southern California are characterized by long, dry summers and cool, wet winters. Previous studies have revealed strategies that fern sporophytes use to survive seasonal drought in the chaparral ecosystem. However, the environmental and physiological factors facilitating survival in the smaller independent fern gametophyte generation remain unknown. Unlike vascular fern sporophytes, fern gametophytes lack complex tissues to support water acquisition and retention. In this study, we propose that microclimate conditions at the soil surface extend the water availability period for fern gametophytes. We hypothesize that the soil-surface microclimate surrounding the fern gametophytes is more humid than the microclimate surrounding the sporophytes. We measured microclimate conditions in situ during early summer, including vapor pressure difference at the leaf (VPDleaf) and leaf temperature. We compared microclimate conditions adjacent gametophyte thalli at the soil surface to conditions adjacent sporophyte leaves. Fern gametophyte thalli and sporophyte leaves experienced significant differences in VPDleaf and leaf temperature throughout the early summer drought. Fern gametophytes experienced higher moisture and more moderate temperature than sporophyte leaves (p > 0.05, n = XXX paired samples). However, fern and moss gametophytes experienced no significant difference in microclimate (p > 0.05, n = XXX paired samples). Furthermore, fern gametophytes frequently experienced negative VPDleaf early in the summer drought, which means that water condensed on the gametophyte thalli. This prolonged period of partial hydration and gradual drying may also facilitate desiccation tolerance in chaparral fern gametophytes. Future studies will further elucidate the environmental limits of survival in fern gametophytes.
Faculty Mentor
Dr. Helen I. Holmlund
Funding Source or Research Program
Academic Year Undergraduate Research Initiative, Summer Undergraduate Research in Biology
Location
Waves Cafeteria
Start Date
22-3-2024 1:30 PM
End Date
22-3-2024 2:30 PM
Chaparral fern gametophytes experience microclimates with more moisture and more moderate temperatures than fern sporophytes
Waves Cafeteria
The chaparral shrublands of southern California are characterized by long, dry summers and cool, wet winters. Previous studies have revealed strategies that fern sporophytes use to survive seasonal drought in the chaparral ecosystem. However, the environmental and physiological factors facilitating survival in the smaller independent fern gametophyte generation remain unknown. Unlike vascular fern sporophytes, fern gametophytes lack complex tissues to support water acquisition and retention. In this study, we propose that microclimate conditions at the soil surface extend the water availability period for fern gametophytes. We hypothesize that the soil-surface microclimate surrounding the fern gametophytes is more humid than the microclimate surrounding the sporophytes. We measured microclimate conditions in situ during early summer, including vapor pressure difference at the leaf (VPDleaf) and leaf temperature. We compared microclimate conditions adjacent gametophyte thalli at the soil surface to conditions adjacent sporophyte leaves. Fern gametophyte thalli and sporophyte leaves experienced significant differences in VPDleaf and leaf temperature throughout the early summer drought. Fern gametophytes experienced higher moisture and more moderate temperature than sporophyte leaves (p > 0.05, n = XXX paired samples). However, fern and moss gametophytes experienced no significant difference in microclimate (p > 0.05, n = XXX paired samples). Furthermore, fern gametophytes frequently experienced negative VPDleaf early in the summer drought, which means that water condensed on the gametophyte thalli. This prolonged period of partial hydration and gradual drying may also facilitate desiccation tolerance in chaparral fern gametophytes. Future studies will further elucidate the environmental limits of survival in fern gametophytes.