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

CAMPANELLA, M.V.; BISIGATO, A.J.; BERTILLER, M. B.

ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY

GAUTHIER-VILLARS/EDITIONS ELSEVIER

Lugar: Paris; Año: 2020 vol. 108 p. 1 - 11

1146-609X

The identification of the main abiotic variables influencing the seasonal development of plant phenology contributes to our knowledge of how arid and semi-arid ecosystems function. In this study, we addressed thefollowing questions: 1. Is soil water content the most important variable determining plant phenophases? 2. Arephenophases across different life forms associated with the soil water content of different layers? We evaluatedthe relationships between environmental variables (i.e. precipitation, air temperature, soil moisture, and daylength) and plant phenophases, using variable-length time periods preceding each measurement. We selected fiverepresentative evergreen shrubs, four deciduous shrubs, and three dominant perennial grasses. All phenophasesrelated to vegetative and reproductive growth, and senescence were registered monthly during three years. Therelationships between plant phenophases and environmental variables were evaluated using Spearman?s correlation. We found that plant phenophases showed stronger association with soil water content and air temperature than precipitation. In most species, vegetative and reproductive phenophases were positively related tosoil water content while leaf senescence was negatively associated. Soil water contents of layers 2 (10?20 cm)and 3 (20?40 cm) were more frequently related to plant phenophases than those of the first (0?10 cm) and fourth(40?100 cm) layers. Significantly correlated environmental variables encompassed previous periods of variablelength depending on the species. Our results highlighted that soil water and air temperature were tightlycorrelated to plant phenophases and that all species seem to use the water contained in the same soil layers.