Summary: We quantified the biomass allocation patterns to leaves, stems and roots in vegetative plants, and how this is influenced by the growth environment, plant size, evolutionary history and competition. Dose–response curves of allocation were constructed by means of a meta‐analysis from a wide array of experimental data. They show that the fraction of whole‐plant mass represented by leaves (LMF) increases most strongly with nutrients and decreases most strongly with light. Correction for size‐induced allocation patterns diminishes the LMF‐response to light, but makes the effect of temperature on LMF more apparent. There is a clear phylogenetic effect on allocation, as eudicots invest relatively more than monocots in leaves, as do gymnosperms compared with woody angiosperms. Plants grown at high densities show a clear increase in the stem fraction. However, in most comparisons across species groups or environmental factors, the variation in LMF is smaller than the variation in one of the other components of the growth analysis equation: the leaf area : leaf mass ratio (SLA). In competitive situations, the stem mass fraction increases to a smaller extent than the specific stem length (stem length : stem mass). Thus, we conclude that plants generally are less able to adjust allocation than to alter organ morphology. Contents Summary 30 I. Allocation in perspective 31 II. Topics of this review 32 III. Methodology 32 IV. Environmental effects 33 V. Ontogeny 36 VI. Differences between species 40 VII. Physiology and molecular regulation 41 VIII. Ecological aspects 42 IX. Perspectives 45 Acknowledgements 45 References 45 Appendices A1–A4 49

Summary: Leaf dark respiration (R_dark) is an important yet poorly quantified component of the global carbon cycle. Given this, we analyzed a new global database of R_dark and associated leaf traits. Data for 899 species were compiled from 100 sites (from the Arctic to the tropics). Several woody and nonwoody plant functional types (PFTs) were represented. Mixed‐effects models were used to disentangle sources of variation in R_dark. Area‐based R_dark at the prevailing average daily growth temperature (T) of each site increased only twofold from the Arctic to the tropics, despite a 20°C increase in growing T (8–28°C). By contrast, R_dark at a standard T (25°C, R_dark²⁵) was threefold higher in the Arctic than in the tropics, and twofold higher at arid than at mesic sites. Species and PFTs at cold sites exhibited higher R_dark²⁵ at a given photosynthetic capacity (V_cmax²⁵) or leaf nitrogen concentration ([N]) than species at warmer sites. R_dark²⁵ values at any given V_cmax²⁵ or [N] were higher in herbs than in woody plants. The results highlight variation in R_dark among species and across global gradients in T and aridity. In addition to their ecological significance, the results provide a framework for improving representation of R_dark in terrestrial biosphere models (TBMs) and associated land‐surface components of Earth system models (ESMs).

Leaf trait data were compiled for 258 Australian plant species from several habitat types dominated by woody perennials. Specific leaf area (SLA), photosynthetic capacity, dark respiration rate and leaf nitrogen (N) and phosphorus (P) concentrations were positively correlated with one another and negatively correlated with average leaf lifespan. These trait relationships were consistent with previous results from global datasets. Together, these traits form a spectrum of variation running from species with cheap but frequently replaced leaves to those with strategies more attuned to a nutrient-conserving lifestyle. Australian species tended to have SLAs at the lower end of the spectrum, as expected in a dataset dominated by sclerophyllous species from low fertility or low rainfall sites. The existence of broad-scale, 'global' relationships does not imply that the same trait relationships will always be observed in small datasets. In particular, the probability of observing concordant patterns depends on the range of trait variation in a dataset, which, itself, may vary with sample size or species-sampling properties such as the range of growth forms, plant functional 'types', or taxa included in a particular study. The considerable scatter seen in these broad-scale trait relationships may be associated with climate, physiology and phylogeny.

• Worldwide, many rare plant species occur in shallow-soil, drought-prone environments. For most of these species, the adaptations required to be successful in their own habitats, as well as their possible consequences for establishment and persistence in others, are unknown. • Here, two rare Hakea (Proteaceae) species confined to shallow-soil communities in mediterranean-climate south-western Australia were compared with four congeners commonly occurring on deeper soils. Seedlings were grown for 7 months in a glasshouse in individual 1.8 × 0.2-m containers, to allow for unconstrained root development. In addition, a reciprocal transplant experiment was carried out. • The rare Hakea species differed consistently from their common congeners in their spatial root placement. They invested more in deep roots and explored the bottom of the containers much more quickly. In the reciprocal transplant experiment they showed increased survival in their own habitat, but not in others. • This research suggests that shallow-soil endemics have a specialized root system that allows them to explore a large rock surface area, thereby presumably increasing their chance to locate cracks in the underlying rock. However, this root-system morphology may be maladaptive on deeper soils, providing a possible explanation for the restricted distribution of many shallow-soil endemics.