Summary Soil nutrient availability can strongly affect root traits. In tropical forests, phosphorus (P) is often considered the main limiting nutrient for plants. However, support for the P paradigm is limited, and N and cations might also control tropical forests functioning. We used a large‐scale experiment to determine how the factorial addition of nitrogen (N), P and cations affected root productivity and traits related to nutrient acquisition strategies (morphological traits, phosphatase activity, arbuscular mycorrhizal colonisation and nutrient contents) in a primary rainforest growing on low‐fertility soils in Central Amazonia after 1 yr of fertilisation. Multiple root traits and productivity were affected. Phosphorus additions increased annual root productivity and root diameter, but decreased root phosphatase activity. Cation additions increased root productivity at certain times of year, also increasing root diameter and mycorrhizal colonisation. P and cation additions increased their element concentrations in root tissues. No responses were detected with N addition. Here we showed that rock‐derived nutrients determined root functioning in low‐fertility Amazonian soils, demonstrating not only the hypothesised importance of P, but also highlighting the role of cations. The changes in fine root traits and productivity indicated that even slow‐growing tropical rainforests can respond rapidly to changes in resource availability.

The productivity of rainforests growing on highly-weathered tropical soils is expected to be limited by phosphorus (P) availability 1 . Yet, controlled fertilisation experiments have failed to demonstrate a dominant role for P in controlling tropical forest net primary productivity (NPP). Recent syntheses have demonstrated that responses to N addition are as large as to P 2 , and adaptations to low P availability appear to allow NPP to be maintained across major soil P gradients 3 . Thus, the extent to which P availability limits tropical forest productivity is highly uncertain. The majority of the Amazonia, however, is characterised by soils even more depleted in P than where most tropical fertilisation experiments have previously taken place 2 . Thus, we established the first P, nitrogen (N), and base cation addition experiment in an old growth Amazon rainforest, with the site's low soil P content representative of ~60% of the basin. Here we show that NPP increased exclusively with P addition. After 2 years, strong responses were observed in fine root (+29%) and canopy productivity (+19%), but not stem growth. The direct evidence of P limitation of NPP suggests that P availability may restrict Amazon forest responses to CO2 fertilisation 4 , with major implications for future carbon sequestration and forest resilience to climate change.

A new species of tree frog from the Scinax catharinae species group is described, discovered in the Municipality of Ouro Preto, southeastern Brazil. The new species is related to Scinax flavoguttatus, but differs from this species mainly by the light green color on its inguinal regions and hidden portions of flanks and thighs, by its subovoid snout, by its developed nuptial pad, and by its smaller males and females. Additionally, we describe the tadpole which is characterized by: dorsal position of nostril; dorsolateral eyes; gold spots between nostrils and eyes, short spiracle; spiracle opening on the midline of dorsal and ventral surface of body; absence of tail flagellum; oral disc with a short dorsal gap, surrounded by a uniseriate marginal papillae; M-shaped upper jaw sheath; tooth row formula 2(2)/3. FIG. 1.-Dorsal and ventral views of Scinax tripui sp. nov., MNRJ 42890 (holotype, 23.0 mm SVL).

No abstract

RESUMOA Serra do Ouro Branco, está localizada na porção sul da Cadeia do Espinhaço, região de transição entre o Cerrado e a Mata Atlântica, no estado de Minas Gerais, Brasil. O objetivo deste estudo foi inventariar os pequenos mamíferos do Parque Estadual da Serra do Ouro Branco (PESOB) e do Monumento Natural Estadual de Itatiaia, unidades de conservação da Serra do Ouro Branco, e comparar com a diversidade encontrada em outras áreas da Cadeia do Espinhaço. A amostragem durou 24 meses (2009)(2010) utilizando pitfall traps. Foram registradas 19 espécies de pequenos mamíferos, 13 de roedores e seis de marsupiais, com um esforço de 6664 armadilhas/noite. A área de estudo apresentou baixa similaridade com outras áreas do Espinhaço. Foram registradas espécies raras e inéditas para esta cadeia de montanhas. Foi detectada elevada dissimilaridade em toda a Cadeia, revelada pelo grande número de ocorrências únicas (40%) e baixo número de espécies que ocorreram em pelo menos metade das áreas inventariadas (17%). Assim, a alta riqueza e diversidade registradas aliadas a particularidade na composição de espécies de cada área e a escassez de dados para a região norte e principalmente central da cadeia do Espinhaço reforçam a importância de mais estudos e inventários de pequenos mamíferos em toda a sua extensão. Palavras-chave: inventário; marsupiais; Quadrilátero Ferrífero; roedores; Serra do Ouro Branco ABSTRACT -SMALL MAMMALS (RODENTIA AND DIDELPHIMORPHIA) FROM SERRA DO OURO BRANCO: SOUTHERN PORTION OF ESPINHAÇO MOUNTAIN RANGE, MINAS GERAIS, BRAZILSerra do Ouro Branco is located at the south portion of Espinhaço Range, at a transition area between Cerrado and Atlantic Forest biomes, in Minas Gerais state, Brazil. Here, we surveyed small mammals communities from Parque Estadual Serra do Ouro Branco and Monumento Natural Estadual do Itatiaia, two protected areas, and compared them with the diversity recorded in the remaining Espinhaço mountain range. Sampling occurred over 24 months (2009)(2010) using pitfall traps. Nineteen species, 13 rodents and six marsupials, were recorded in 6,664 traps /night. The study area has low similarity with other areas of Espinhaço Range; high dissimilarity was the main pattern found, as revealed by the large number of singletons (40%) and few species found at least in half of the areas (17%). Thus, the elevated richness and diversity registered allied to the singularity in composition of species in each area and the scarcity of data for the north and mainly for the central region of Espinhaço, reinforce the importance and urgency of more studies and inventories of small mammals in all mountain range extension.