Decoupled evolution of foliar freezing resistance, temperature niche and morphological leaf traits in Chilean Myrceugenia

Abstract

Summary1. Phylogenetic conservatism of tolerance to freezing temperatures has been cited to explain the tendency of plant lineages to grow in similar climates. However, there is little information about whether or not freezing resistance is conserved across phylogenies, and whether conservatism of physiological traits could explain conservatism of realized climatic niches. Here, we compared the phylogenetical lability of realized climatic niche, foliar freezing resistance and four morphological leaf traits that are generally considered to be adaptations to frost resistance in the Chilean species of Myrceugenia, which grows in a wide range of habitats. 2. We estimated the predicted niche occupancy profiles with respect to minimum temperature (minT) of all species. We measured foliar freezing resistance (using chlorophyll fluorescence), leaf size, leaf mass per area (LMA), stomatal and trichome densities of 10 individuals per species. Finally, we estimated phylogenetic signal, and we performed independent contrast analyses among all variables. 3. We found that both foliar freezing resistance and minT were subject to a significant phylogenetic signal, but the former had a stronger signal. We also detected a significant, but weak correlation between them (r = 0.49, P one tail = 0.04). Morphological traits evolved independent of any phylogenetic effect. 4. Synthesis. Our results show that freezing resistance evolved in association with temperature niche, but with some delay that could result from phylogenetic inertia. Our results also show that morphological leaf traits are more labile than realized climatic niche and frost tolerance and that the formers probably evolved in association with microhabitat preferences.

Integrating physiological threshold experiments with climate modeling to project mangrove species’ range expansion

“…Change in yield is a common freeze tolerance metric (Cavender‐Bares et al . ; Pérez et al ., ) that correlates with other freeze tolerance metrics (Boorse et al . ).…”

“…). We measured yield before and after the freeze treatment with a mini‐PAM (Photosynthetic Yield Analyzer; Walz, Mess‐ und Regeltechnik, Effeltrich, Germany) and quantified photoinactivation as 1− Y post / Y max (Pérez et al ., ). Photoinactivation thus ranged from zero (no loss of photosynthetic function) to one (complete loss of photosynthetic function).…”

Convergence of three mangrove species towards freeze‐tolerant phenotypes at an expanding range edge

“…We measured yield before and after the freeze treatment with a mini‐PAM (Photosynthetic Yield Analyzer, Walz, Mess‐ und Regeltechnik, Germany) and quantified photoinactivation as 1 − Y post / Y max (Pérez et al . ). Photoinactivation thus ranged from zero (no loss of photosynthetic function) to one (complete loss of photosynthetic function).…”

Community-weighted mean traits but not functional diversity determine the changes in soil properties during wetland drying on the Tibetan Plateau

“…At the same time, plant functional traits play an important role in predicting the patterns of species composition, community structure, and their responses to environment change, which has drawn substantial ecological interest (e.g., Wright et al, 2004;McGill et al, 2006;Pérez et al, 2014;Li et al, 2015a); however, it is not clear whether functional traits and functional diversity (i.e., the identity, abundance, and range of species in a given community) can reflect the changes in soil properties during wetland drying on the Tibetan Plateau. A growing body of evidence has shown that functional diversity is directly linked with ecosystem processes (McGill et al, 2006;Flynn et al, 2011).…”