The “hierarchy of factors” hypothesis states that decomposition rates are controlled primarily by climatic, followed by biological and soil variables. Tropical montane forests (TMF) are globally important ecosystems, yet there have been limited efforts to provide a biome‐scale characterization of litter decomposition. We designed a common litter decomposition experiment replicated in 23 tropical montane sites across the Americas, Asia, and Africa and combined these results with a previous study of 23 sites in tropical lowland forests (TLF). Specifically, we investigated (1) spatial heterogeneity in decomposition, (2) the relative importance of biological factors that affect leaf and wood decomposition in TMF, and (3) the role of climate in determining leaf litter decomposition rates within and across the TMF and TLF biomes. Litterbags of two mesh sizes containing Laurus nobilis leaves or birchwood popsicle sticks were spatially dispersed and incubated in TMF sites, for 3 and 7 months on the soil surface and at 10–15 cm depth. The within‐site replication demonstrated spatial variability in mass loss. Within TMF, litter type was the predominant biological factor influencing decomposition (leaves > wood), with mesh and burial effects playing a minor role. When comparing across TMF and TLF, climate was the predominant control over decomposition, but the Yasso07 global model (based on mean annual temperature and precipitation) only modestly predicted decomposition rate. Differences in controlling factors between biomes suggest that TMF, with their high rates of carbon storage, must be explicitly considered when developing theory and models to elucidate carbon cycling rates in the tropics. Abstract in Spanish is available with online material.

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Cinchona officinalis is an important species from the Andean cloud forest that has a low regeneration rate in natural populations. In vitro regeneration of C. officinalis has been successfully established but somaclonal variation was not evaluated. The regeneration pathway and the number of subcultures on somaclonal variation were evaluated using six ISSR primers that amplified 58 loci of Inter Simple Sequence Repeats (ISSR). A dendrogram based on Jaccard´s genetic distance between the subcultures and the donor plant was produced. The results show that indirect shoot regeneration induces somaclonal variation, in the presence 2,4-Dichlorophenoxyacetic acid (2,4-D) in combination with kinetin and 6-Benzylaminopurine (BAP). In combination with 1-Naphthaleneacetic acid (NAA) or with Indole-3-butyric acid (IBA), BAP produces genetically stable explants. The highest proliferation rate was achieved using BAP and IBA. The present research study suggests avoiding the use of 2,4-D when C. officinalis is propagated for reintroduction and restoration projects.

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