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•Experimental evidence demonstrates a higher efficiency of water and nitrogen use in C4 compared with C3 plants, which is hypothesized to drive differences in biomass allocation between C3 and C4 species. However, recent work shows that contrasts between C3 and C4 grasses may be misinterpreted without phylogenetic control. •Here, we compared leaf physiology and growth in multiple lineages of C3 and C4 grasses sampled from a monophyletic clade, and asked the following question: which ecophysiological traits differ consistently between photosynthetic types, and which vary among lineages? •C4 species had lower stomatal conductance and water potential deficits, and higher water-use efficiency than C3 species. Photosynthesis and nitrogen-use efficiency were also greater in C4 species, varying markedly between clades. Contrary to previous studies, leaf nitrogen concentration was similar in C4 and C3 types. Canopy mass and area were greater, and root mass smaller, in the tribe Paniceae than in most other lineages. The size of this phylogenetic effect on biomass partitioning was greater in the C4 NADP-me species than in species of other types. •Our results show that the phylogenetic diversity underlying C4 photosynthesis is critical to understanding its functional consequences. Phylogenetic bias is therefore a crucial factor to be considered when comparing the ecophysiology of C3 and C4 species. [ABSTRACT FROM AUTHOR]

The authors reflect on the research by Frederic Lens and colleagues which won the 2010 Tansley Medal from the journal "New Phytologist." They state that the research offers insights on the association between the anatomy of wood and hydraulic conductivity in trees. They mention that Lens and colleagues used various techniques and examined seven taxa of the genus Acer, resulting to the influences of membrane thickness, porosity, and lower xylem conductivity to cavitation resistance.

The dynamic relationship between vegetation and climate is now widely acknowledged. Climate influences the distribution of vegetation; and through a number of feedback mechanisms vegetation affects climate. This implies that land-use changes such as deforestation will have climatic consequences. However, the spatial scales at which such feedbacks occur remain largely unknown. Here, we use a large database of precipitation and tree cover records for an area of the biodiversity-rich Atlantic forest region in south eastern Brazil to investigate the forest-rainfall feedback at a range of spatial scales from ca 10(1)-10(4) km2. We show that the strength of the feedback increases up to scales of at least 10(3) km2, with the climate at a particular locality influenced by the pattern of landcover extending over a large area. Thus, smaller forest fragments, even if well protected, may suffer degradation due to the climate responding to land-use change in the surrounding area. Atlantic forest vertebrate taxa also require large areas of forest to support viable populations. Areas of forest of ca 10(3) km2 would be large enough to support such populations at the same time as minimizing the risk of climatic feedbacks resulting from deforestation.