Advantages of rainfall partitioning by the global invader Ligustrum lucidum over the dominant native Lithraea molleoides in a dry forest

WHITWORTH-HULSE, JUAN I.; MAGLIANO, PATRICIO N.; ZEBALLOS, SEBASTIÁN R.; GURVICH, DIEGO E.; SPALAZZI, FLORENCIA; KOWALJOW, ESTEBAN

AGRICULTURAL AND FOREST METEOROLOGY

ELSEVIER SCIENCE BV

Año: 2020

0168-1923

Vegetation canopy plays a key role in the local water balance by partitioning rainfall into interception,throughfall and stemflow in dry forests. Many invasive plants have the capacity to replace native species andalter the net amount and spatial distribution of rainfall reaching the soil. In this paper, we aimed to compare therainfall partitioning for the invader Ligustrum lucidum and the dominant native Lithraea molleoides, to evaluatethe influence of morphological characteristics on stemflow generation in both species, and to explore spatiotemporalpatterns of throughfall at stand scale. Stemflow percentage for L. lucidum was hugely higher than for L.molleoides (18 and 1%, respectively), which overcompensated its lower throughfall percentage (58.1 and 68.6%,respectively). Interception losses were lower for L. lucidum than for L. molleoides (23.2 and 30.6%, respectively).The minimum rainfall amount needed to generate throughfall and stemflow was 1.8 and 0.5 mm for L. lucidum,while 2.2 and 7.2 mm for L. molleoides. The differences in morphological characteristics between species mainlyexplained the stemflow generation. The increment on tree basal area, projected canopy area, and number ofbranches favored stemflow in L. lucidum, but not in L. molleoides. The throughfall spatial patterns showed that thedripping from different canopy densities was homogenous in L. lucidum stands, whereas throughfall increasetowards more opened-canopies in L. molleoides stands. Lateral inflows were registered from small-scale crownsections at both forest stands, but less frequent in L. lucidum stands. The time stability of throughfall patterndiffered between forest stands. Based on our results, relatively higher stemflow and lower interception losses forL. lucidum than for L. Molleoides may represent a competitive advantage in terms of plant invasion in waterlimitedecosystems. These findings highlight the need for further inquiries determining the underlying role ofrainfall partitioning in the invasion process of woody species.