Abstract Detail



Ecology

Arenas Navarro, Maribel [3], Terrazas, Teresa [1], García Oliva, Felipe [2], Torres Miranda, Andres [3], Oyama, Ken [3].

The role of wood anatomical traits in the coexistence of oak species along an environmental gradient.

Plant species distribution results from trait composition through environmental filters, such as water availability. In regions where water resource availability is heterogeneous, niche partitioning facilitates the spatial segregation of plant species and promotes high diversity. In woody angiosperms, water transport is conducted through vessels (and nutrients transport), the distribution of water is by fibers (mechanical support) and parenchyma (metabolite transport and water storage). Variation in wood anatomical traits along environmental gradients represents adaptive structural solutions to achieve an optimal balance among the competing needs of support, storage, and transport. In this study, we analyzed the wood anatomical traits and the relative hydraulic conductivity of 21 oak species to identify their performance according to abiotic factors, leaf phenological patterns, and phylogenetic restrictions by analyzing the interspecific variation along an environmental gradient. First, we determine the causes of anatomical trait variation in the oaks, analyzing the wood functional trade-offs related to distribution along the environmental gradient. We measure the phenotypic plasticity of the anatomical traits to determine the role of environment and geographic distance in the range of phenotypic plasticity in the wood traits. Second, we examined if oaks co-occurred along the environmental gradient, and we analyzed if wood anatomical traits reflect differences among their phylogenetic section, leaf habit, and a phylogenetic section/leaf habit category. Last, we investigated phylogenetic signals for all traits using Blomberg’s K. We found a negative relationship between vessel diameter and frequency and both varied inversely with wood density. The oak species analyzed wide vessels in lower frequency led to lower wood densities. The phylogenetic generalized least squares analysis determined that the aridity index and seasonal precipitation drive the variation in the analyzed traits, and higher environmental distance resulted in a higher relative distance plasticity index among traits. We analyzed 231 species pairs for the co-occurrence models, and these models revealed nine positive associations formed mostly among red and white oaks. Our results showed that vessel diameter, vessel frequency, wood density, and relative hydraulic conductivity are the main axes of trait variation in the species analyzed among leaf habit categories. Lastly, the wood traits tested in this study showed low phylogenetic signals. This study found that high temperatures in combination with periodic water deficits lead to narrower vessels, high-density wood occupied by smaller fibers. On the contrary, on humid sites, tall oaks invest in widest vessels to conduct water with great efficiency and increasing conductivity in combination with lower wood density. In the floristic region of Serranias Meridionales de Jalisco in northwestern Mexico, the oaks species showed an adaptive response of wood traits to climate, but there is also evidence of a low phylogenetic signal. Co-occurrence of oak species with different leaf habits and phylogenetic trajectories may promote complementary resource acquisition. The phylogenetic signal in the oak species studied was low, implying labile wood traits. The combination of plasticity and lability in wood traits among Mexican oaks gives an efficient trait configuration for the water-use strategy along environmental gradients.


Related Links:
http://doi.org/10.1093/aobpla/plab066


1 - Universidad Nacional Autónoma de México, Instituto de Biología, Ciudad Universitaria, Coyoacán, CDMX, CDMX, 04510, Mexico
2 - Instituto de Investigaciones en Ecosistemas y Sustentabilidad, Antigua Carretera a Pátzcuaro 8701, Morelia, MICH, 58190, Mexico
3 - Escuela Nacional de Estudios Superiores Unidad Morelia, Antigua Carretera a Pátzcuaro 8701, Morelia, MICH, 58190, Mexico

Keywords:
aridity index
Quercus
fiber
relative hydraulic conductivity.

Presentation Type: Poster
Number: PEC006
Abstract ID:523
Candidate for Awards:None


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