Seasonal variability of dry matter content and its relationship with shoot growth and nonstructural carbohydrates.
This study assesses how different phases of shoot growth underlie seasonal change in leaf and stem dry matter content (LDMC and SDMC, respectively) of 12 woody Mediterranean species. The relationship between LDMC and nonstructural carbohydrate (NSC) concentrations is also explored and the seasonal vs interspecies variability of LDMC compared. LDMC, SDMC and shoot elongation rate (SER) were measured on a monthly basis for a minimum of 12 months. Bud growth rate (BGR) and NSC concentrations were also assessed in several of the study species. LDMC and SDMC decreased during shoot elongation in spring and increased in summer, showing a significant negative correlation with SER, but were unrelated to BGR. Half of the species analysed showed a positive relationship between LDMC and NSC. Seasonal fluctuations of LDMC within species were higher than interspecies differences, and species ranking was significantly affected by the month of sampling, except during winter months. Seasonal changes in LDMC and SDMC are mainly related to shoot elongation phenology, and NSC sink-source relationships between old and growing organs can explain this relationship in some species. Owing to the high seasonal variability in LDMC, it is recommended that samples for comparative purposes should be collected as close to the winter as possible.
Palacio
Sara
S
Instituto Pirenaico de Ecología (CSIC). Apdo. 202, 50192 Zaragoza, Spain.|Current address: Macaulay Institute, Craigiebuckler, Aberdeen AB15 8QH, UK.
Milla
Rubén
R
Area de Biodiversidad y Conservación, Universidad Rey Juan Carlos. C/Tulipán s/n, 28933 Móstoles-Madrid, Spain.
Albuixech
Jorge
J
Instituto Pirenaico de Ecología (CSIC). Apdo. 202, 50192 Zaragoza, Spain.
Pérez-Rontomé
Carmen
C
Estación Experimental de Aula Dei (CSIC), Avda Montañana 1.005-50192 Zaragoza, Spain.
Camarero
Jesús Julio
JJ
Instituto Pirenaico de Ecología (CSIC). Apdo. 202, 50192 Zaragoza, Spain.
Maestro
Melchor
M
Instituto Pirenaico de Ecología (CSIC). Apdo. 202, 50192 Zaragoza, Spain.
Montserrat-Martí
Gabriel
G
Instituto Pirenaico de Ecología (CSIC). Apdo. 202, 50192 Zaragoza, Spain.
D050260:Carbohydrate Metabolism; D063245:Plant Development; D018515:Plant Leaves / Q000254:growth & development / Q000378:metabolism; D018520:Plant Shoots / Q000254:growth & development / Q000378:metabolism; D018547:Plant Stems / Q000254:growth & development / Q000378:metabolism; D010944:Plants / Q000378:metabolism*; D012621:Seasons; D013045:Species Specificity