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& Key message Cloud forest tree seedlings of higher leaf mass to area ratio and leaf dry matter content displayed higher survival along an elevation gradient in the forest understorey. Phenotypic plasticity in leaf functional traits was not related to seedling survival. & Context Understanding the relationship between seedling survival and phenotypic plasticity of leaf functional traits is of great importance for predicting tree species responses to climate change. & Aims We analysed whether phenotypic plasticity and mean values of leaf functional traits could serve as predictors of cloud forest tree seedling survival along an elevation gradient. & Methods We measured survival, leaf mass area (LMA) and leaf dry matter content (LDMC) in planted tree seedlings of 13 shade-tolerant tropical cloud forest species in nine forest understorey sites along an elevation gradient in southern Mexico. Phenotypic plasticity in LMA and LDMC was calculated based on inter-individual phenotypic variation to different elevations. & Results Intraspecific differences in LMA and LDMC occurred with elevation. Across the elevation range, seedlings with higher mean LMA and LDMC had higher survival. Plasticity in leaf traits was small and was not related to survival. & Conclusion Our results support that mean LMA, and to a lesser extent mean LDMC, could be good predictors of cloud forest tree seedling survival along elevation gradients. The small leaf trait plasticity found does not affect the survival of seedlings in the forest understorey along the elevation gradient.

The capacity of Cladosporium cladosporioides biomass for removal of Cr(VI) in aqueous solutions was evaluated. A 2 × 2 factorial experiment design was used to study the effects of pH and biomass doses. Lower pH values and larger biomass doses increased the capacity of C. cladosporioides biomass for removal of Cr(VI), reaching a reduction capacity of 492.85 mg g, a significantly higher value compared to other biomass reported. Cr(VI) removal kinetic rates followed a pseudo-second order model, like other fungal biomass reported previously. The apparent adsorption process was described well by the Freundlich isothermal model. However, determination of total chromium indicated that adsorption of Cr(VI) was followed by a redox reaction that released proportional quantities of Cr(III) into the experimental supernatant, suggesting a parallel adsorption-reduction process. Comparison of Fourier transform infrared spectroscopy spectra of C. cladosporioides biomass before and after the reduction process demonstrated the involvement of positively charged amino groups in the Cr(VI) adsorption-reduction process.

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Acorn removal and predation are processes that can influence forest dynamics and the ecological niche segregation of sympatric oak species. Different factors affect these processes, including differences in acorn germination rate and exposure to predators and/or dispersers. This study evaluated acorn removal and predation patterns in three threatened tropical cloud forest oak species (Quercus germana, Quercus sartorii and Quercus cortesii). Acorns were placed in two accessibility treatments (open to all potential acorn consumers vs. accessible to mice only) and in two types of microhabitat (covered by trunks, shrubs and herbaceous plants vs. uncovered). In addition, acorn germination rate was evaluated in a greenhouse. After 130 days, 76.67 ± 2.45 % of the seeds had been removed and the two accessibility treatments did not differ significantly. Mice were therefore shown as important predators and/or dispersers of acorns. Removal was greater in the covered (93.33 ± 2.04 %) compared to the uncovered (60.00 ± 4.01 %; P < 0.05) microhabitat. Acorn removal and germination were highest for Q. germana (82.00 ± 3.86 %, 91.67 ± 4.41 %, respectively), followed by Q. sartorii (79.00 ± 4.09 %; 50.00 ± 7.64 %) and Q. cortesii (69.00 ± 4.64 %; 13.33 ± 4.41 %); the same trend was recorded in the acorn germination rate (P < 0.05). Our findings suggest that uncovered sites with partial shade might function as regeneration microhabitats where less acorn removal and higher germination occur. The implications of differential acorn trait preferences by rodents for the coexistence of these oak species are discussed.