Insular woody daisies (Argyranthemum, Asteraceae) are more resistant to drought‐induced hydraulic failure than their herbaceous relatives
CHAUVIN, Thibaud
Biologie intégrée pour la valorisation de la diversité des arbres et de la forêt [BioForA]
< Leer menos
Biologie intégrée pour la valorisation de la diversité des arbres et de la forêt [BioForA]
Idioma
en
Article de revue
Este ítem está publicado en
Functional Ecology. 2018, vol. 32, n° 6, p. 1467-1478
Wiley
Resumen en inglés
1- Insular woodiness refers to the evolutionary transition from herbaceousness towards derived woodiness on (sub)tropical islands and leads to island floras that have a higher proportion of woody species compared to floras ...Leer más >
1- Insular woodiness refers to the evolutionary transition from herbaceousness towards derived woodiness on (sub)tropical islands and leads to island floras that have a higher proportion of woody species compared to floras of nearby continents. 2- Several hypotheses have tried to explain insular woodiness since Darwin's original observations, but experimental evidence why plants became woody on islands is scarce at best. 3- Here, we combine experimental measurements of hydraulic failure in stems (as a proxy for drought stress resistance) with stem anatomical observations in the daisy lineage (Asteraceae), including insular woody Argyranthemum species from the Canary Islands and their herbaceous continental relatives. 4- Our results show that stems of insular woody daisies are more resistant to drought‐induced hydraulic failure than the stems of their herbaceous counterparts. The anatomical character that best predicts variation in embolism resistance is intervessel pit membrane thickness (TPM), which can be functionally linked with air bubble dynamics throughout the 3D vessel network. There is also a strong link between TPM vs. degree of woodiness and thickness of the xylem fibre wall vs. embolism resistance, resulting in an indirect link between lignification and resistance to embolism formation. 5- Thicker intervessel pit membranes in Argyranthemum functionally explain why this insular woody genus is more embolism resistant to drought‐induced failure compared to the herbaceous relatives from which it has evolved, but additional data are needed to confirm that palaeoclimatic drought conditions have triggered wood formation in this daisy lineage.< Leer menos
Palabras clave
hydraulic failure
xylem hydraulics
Palabras clave en inglés
canary Islands
drought
insular woodiness
lignification
stem anatomy
thickness of intervessel pit membrane
Orígen
Importado de HalCentros de investigación