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Evidence is accumulating that significant amounts of substances can move internally in ectohydric bryophytes, which lack specialized structures for internal water movement. This potential for resource translocation is likely to affect the productivity in individual shoot sections. We tested whether annual growth intervals in the pleurocarpous moss Pseudocalliergon trifarium were performing as independent units by comparing the biomass of annual increments within individual shoots from 13 populations from northern and central Sweden. Pseudocalliergon trifarium has a distinct shoot architecture with discrete annual segments and is therefore well suited to study annual biomass allocation patterns. Mass of the most recent growth interval was directly correlated with segment mass of at least two preceding years. The strength of the relationship between current growth and four consecutively older annual increments decreased linearly with age of the annual segments, suggesting that correlations within shoots were the result of resource translocation rather than of among-year correlations in local environmental factors. Our data suggest that interconnected segments are physiologically integrated, and that size relationships between successive increments are relatively independent of environmental conditions. We conclude that annual growth intervals cannot be considered as independent assimilatory units. Internal resource transfer across annual segments may buffer variation in external availability of or internal demands for resources, and has implications for the understanding of growth patterns and reproductive investments in ectohydric bryophytes.

Habitat preferences and habitat differentiation were studied among species of Acroporium (Sematophyllaceae) and related taxa between 140–2,000 m a.s.l. in Peninsular Malaysia (02.92°–04.87°N, 100.80°–101.83°E). Canonical Correspondence Analysis was used to reveal how species data were related to 16 environmental factors that represent geographical, physical environmental, chemical, and substrate type components. We found some geographical variation, but this explained little of the species distribution patterns. A minimum model based on automatic forward selection suggested that elevation, the substrate peaty soil, and pH explain 57% of the variation in the species data, and variation partitioning suggests that much of the variation in the latter is explained by several factors in combination. Light availability and the substrate mineral soil were of moderate importance in explaining species data distribution, whereas other variables influenced the variation less and mainly along the third and fo...