Environmental controls of plant phenology in twelve desert plant species in the Patagonian Monte, Argentina

MARÍA VICTORIA CAMPANELLA; ALEJANDRO J. BISIGATO; MÓNICA B. BERTILLER

ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY

GAUTHIER-VILLARS/EDITIONS ELSEVIER

Lugar: Paris; Año: 2020

1146-609X

The identification of the main abiotic variablesinfluencing the seasonal development of plant phenology contributes to ourknowledge of how arid and semi-aridecosystems function. In this study, we addressed the following questions: 1. Issoil water content the most important variable determining plant phenophases?2. Are phenophases across different life forms associated with the soil watercontent of different layers? We evaluated the relationships between environmentalvariables (i.e. precipitation, air temperature, soil moisture, and day length)and plant phenophases, using variable-length time periods preceding each measurement.We selected five representative evergreen shrubs, four deciduous shrubs, and threedominant perennial grasses. All phenophases related to vegetative andreproductive growth, and senescence were registered monthly during three years.The relationships between plant phenophases and environmental variables wereevaluated using Spearman?s correlation. We found that plant phenophases showedstronger association with soil water content and air temperature than precipitation.In most species, vegetative and reproductive phenophases were positivelyrelated to soil water content while leaf senescence was negatively associated. Soil water contentsof layers 2 (10-20 cm) and 3 (20-40 cm) were more frequently related to plantphenophases than those of the first (0-10 cm) and fourth (40-100 cm) layers. Significantlycorrelated environmental variables encompassed previous periods of variablelength depending on the species. Our results highlighted that soil water andair temperature were tightly correlated to plant phenophases and that allspecies seem to use the water contained in the same soil layers.