There are a number of controversies surrounding both biomass estimation and carbon balance in tropical forests. Here we use long-term (from 1978 through 2000) data from five 0.5-ha permanent sample plots (PSPs) within a large tract of relatively undisturbed Atlantic moist forest in southeastern Brazil to quantify the biomass increment (DeltaM(I)), and change in total stand biomass (DeltaM(stand)), from mortality, recruitment, and growth data for trees >/=10 cm diameter at breast height (DBH). Despite receiving an average of only 1,200 mm annual precipitation, total forests biomass (334.5+/-11.3 Mg ha(-1)) was comparable to moist tropical forests with much greater precipitation. Over this relatively long-term study, forest biomass experienced rapid declines associated with El Niño events, followed by gradual biomass accumulation. Over short time intervals that overlook extreme events, these dynamics can be misinterpreted as net biomass accumulation. However for the 22 years of this study, there was a small reduction in forest biomass, averaging -1.2 Mg ha(-1) year(-1) (+/-3.1). Strong climatic disturbances can severely reduce forest biomass, and if the frequency and intensity of these events increases beyond historical averages, these changing disturbance regimes have the capacity to significantly reduce forest biomass, resulting in a net source of carbon to the atmosphere.

Cocoa (Theobroma cacao) is cultivated in the states of Bahia and Espírito Santo in easternBrazil under the so-called 'cabruca system', where the understorey of native Atlantic forest is cleared and the canopy is thinned out to provide adequate shading for the cocoa trees. Apart from its economic and social role, the cabruca system is said to be important for the conservation of Atlantic forest biodiversity. In this paper we studied tree species richness and forest structure of cabrucas to examine the demographic health of these forests and discuss their long-term survival. Data were collected in 20 farms located alongside a 30 km track of the northern margin of the Rio Doce, in northern Espírito Santo. All trees !5 cm DBH were identified and their diameter was measured in 80 plots (600 m 2 ), totalling 4.8 ha of sampled area. Recorded trees were also allocated to four different regeneration phases (pioneers, early secondary, late secondary and climax). The inventory resulted in 507 trees belonging to 105 species in 39 families. This species richness is much lower than in less disturbed forests located in the region. Pioneers and early secondary species dominate the cabruca forest in terms of number of species (56.2%), density (71.0%) and basal area (72.3%). The distribution of diameter frequency showed an imbalance in tree regeneration. Most trees in the range of 5-30 cm DBH were pioneers (40.7%), or early secondary species (32.6%), while late secondary and climax trees were less frequent (10.2 and 16.5% of the sampled trees, respectively). The dominance of species of early regeneration phases was also observed for trees >30 cm DBH (69.0% of pioneers or early secondary and 31.0% of late secondary or climax species). The results indicated that the cabruca forests are not only less diverse and less dense than secondary or primary forests of the region, but also, and more importantly, their natural succession and gap dynamics are being severely impaired. As a consequence, cabrucas present a structure where tree species of late successional phases are becoming increasingly rare while pioneers and early secondary species are becoming dominant. If current management practices of thinning and clearing of native trees are not improved, the long-term survival of these forests is questionable and their role in maintaining biodiversity in the long run is limited.

RESUMOMedidas precisas de volume de madeira são ferramentas importantes no planejamento do uso do recurso florestal. Neste estudo, foram investigados modelos volumétricos para a Floresta Nacional do Tapirapé-Aquirí, na Serra dos Carajás (PA), baseados numa cubagem rigorosa de 55 árvores para obter o diâmetro, altura comercial do fuste e volume sólido. Um total de 8 modelos de dupla entrada e 4 de simples entrada foram testados para o diâmetro mínimo de 14 cm. Para seleção do melhor modelo foram usadas as estatísticas do coeficiente de determinação, erro padrão da estimativa e distribuição dos resíduos. Entre os modelos de simples entrada o modelo logarítmico de Husch se ajustou melhor aos dados (R 2 = 0,9105) e entre os de dupla entrada o logarítmico de Schumacher & Hall se ajustou melhor (R 2 = 0,9942). O uso do modelo da Flona de Tapajós ou o uso do modelo de volume cilíndrico com fator de forma 0,7 subestimam a volumetria na Flona do Tapirapé. Isso enfatiza a importância de modelos volumétricos locais para melhorar a precisão da estimativa de madeira. PALAVRAS-CHAVEEquações de volume, modelos logarítmicos, manejo florestal, floresta tropical, Carajás. Volumetric models for Tapirapé-Aquirí

Plinio Sist 10,88 | Bonaventure Sonke 60 | J. Daniel Soto 21 | Cintia Rodrigues de Souza 24 | Juliana Stropp 89 | Martin J. P. Sullivan 35 | Ben Swanepoel 34 | Hans ter Steege 25,90 | John Terborgh 91,92 | Nicolas Texier 93 | Takeshi Toma 94 | Renato Valencia 95 | Luis Valenzuela 75 | Leandro Valle Ferreira 96 | Fernando Cornejo Valverde 97 | Tinde R. Van Andel 25 | Rodolfo Vasque 77 | Hans Verbeeck 61 | Pandi Vivek 22 | Abstract Aim:Large tropical trees form the interface between ground and airborne observations, offering a unique opportunity to capture forest properties remotely and to investigate their variations on broad scales. However, despite rapid development of metrics to characterize the forest canopy from remotely sensed data, a gap remains between aerial and field inventories. To close this gap, we propose a new pan-tropical model to predict plot-level forest structure properties and biomass from only the largest trees.Location: Pan-tropical.Time period: Early 21st century. Major taxa studied: Woody plants.Methods: Using a dataset of 867 plots distributed among 118 sites across the tropics, we tested the prediction of the quadratic mean diameter, basal area, Lorey's height, community wood density and aboveground biomass (AGB) from the ith largest trees. Results:Measuring the largest trees in tropical forests enables unbiased predictions of plot-and site-level forest structure. The 20 largest trees per hectare predicted quadratic mean diameter, basal area, Lorey's height, community wood density and AGB with 12, 16, 4, 4 and 17.7% of relative error, respectively. Most of the remaining error in biomass prediction is driven by differences in the proportion of total biomass held in medium-sized trees (50-70 cm diameter at breast height), which shows some continental dependency, with American tropical forests presenting the highest proportion of total biomass in these intermediate-diameter classes relative to other continents. Main conclusions:Our approach provides new information on tropical forest structure and can be used to generate accurate field estimates of tropical forest carbon stocks to support the calibration and validation of current and forthcoming space missions. It will reduce the cost of field inventories and contribute to scientific understanding of tropical forest ecosystems and response to climate change. K E Y W O R D Scarbon, climate change, forest structure, large trees, pan-tropical, REDD+, tropical forest ecology

SignificanceIdentifying and explaining regional differences in tropical forest dynamics, structure, diversity, and composition are critical for anticipating region-specific responses to global environmental change. Floristic classifications are of fundamental importance for these efforts. Here we provide a global tropical forest classification that is explicitly based on community evolutionary similarity, resulting in identification of five major tropical forest regions and their relationships: (i) Indo-Pacific, (ii) Subtropical, (iii) African, (iv) American, and (v) Dry forests. African and American forests are grouped, reflecting their former western Gondwanan connection, while Indo-Pacific forests range from eastern Africa and Madagascar to Australia and the Pacific. The connection between northern-hemisphere Asian and American forests is confirmed, while Dry forests are identified as a single tropical biome.

RESUMO -(Composição florística do estrato arbóreo da Floresta Estacional Semidecidual na Planície Aluvial do rio Doce, Linhares, ES, Brasil). Este trabalho apresenta a flora de espécies arbóreas e palmeiras na floresta estacional semidecidual na planície aluvial do rio Doce, uma área de cerca de 20.000 ha, a partir de Linhares (ES) até próximo à foz no oceano atlântico. Foram determinadas 408 espécies (27 classificadas em gênero) e 59 famílias, entre arbóreas e palmeiras. Por meio da análise de agrupamento, foi evidenciado que a floresta do rio Doce é muito semelhante floristicamente à floresta estacional dos tabuleiros terciários, que estas se agrupam com as florestas estacionais do rio Doce em MG e que, por sua vez, todas estas se agrupam com as florestas ombrófilas do sul da Bahia, sendo o conjunto nitidamente separado das outras formações ombrófilas costeiras. Foram encontradas dezenas de espécies deocorrência restrita ou pouco frequentes em levantamentos na floresta atlântica, enfatizando a importância da área para conservação da biodiversidade. Pelo fato das matas de cacau na região abrangerem mais de 80% dessa área, sugere-se a delimitação de uma Área de Proteção Ambiental, que permita conciliar o cultivo do cacau com a proteção da biodiversidade.Palavras-chave: rio Doce, floresta atlântica, floresta de tabuleiro, composição florística, cacau ABSTRACT -(Floristic composition of the tree layer in Atlantic forest on the rio Doce alluvial floodplain, Espírito Santo State, Brazil). The tree and palm flora was studied in the Atlantic forest of the rio Doce alluvial floodplain, in a 20,000 ha area, between Linhares (Espírito Santo State) and the Atlantic Ocean. The floristic survey recorded 408 species and 59 families. Floristic composition was compared to other forests of São Paulo, Minas Gerais, Bahia and Rio de Janeiro states using cluster analysis. The forest flora of the study area was most similar to that of forests in Espírito Santo, Minas Gerais, and Bahia. Dozens of species in the study area are restricted and rare in Atlantic forest; this area deserves special attention for biodiversity conservation. The Brazilian government should pay heed to the biological importance of this area and declare it an Environmental Protection Area, a type of conservation unit where sustained exploitation of resources is legal. We understand that, in practical terms, this sort of conservation unit is not very efficient in conserving natural resources, but it would be a start and might contribute to improved awareness, especially by local farmers and politicians.

Xenarthrans—anteaters, sloths, and armadillos—have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, 10 anteaters, and 6 sloths. Our data set includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the southern United States, Mexico, and Caribbean countries at the northern portion of the Neotropics, to the austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n = 5,941), and Cyclopes sp. have the fewest (n = 240). The armadillo species with the most data is Dasypus novemcinctus (n = 11,588), and the fewest data are recorded for Calyptophractus retusus (n = 33). With regard to sloth species, Bradypus variegatus has the most records (n = 962), and Bradypus pygmaeus has the fewest (n = 12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other data sets of Neotropical Series that will become available very soon (i.e., Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans data set. Please cite this data paper when using its data in publications. We also request that researchers and teachers inform us of how they are using these data.

In this study, seedling growth and herbivory were monitored during the first 4 years of plot development in a large-scale reforestation experiment in Brazil's Atlantic Rainforest (Mata Atlântica). Seedlings were planted in a factorial design testing two levels of density, three levels of diversity, and the presence or absence of pioneer species at the Reserva Natural Vale in the Brazilian state of Espírito Santo. In addition, we studied the effect of herbivory on seedling growth and the potential for plant defenses to limit herbivory. Seedling growth was higher in the low-density plantings, and seedlings attained the greatest height in the low-diversity plots, which had a higher density of fast-growing species. The inclusion of pioneer species resulted in a significant decrease in the growth of neighboring seedlings. Interactions between herbivory, plant defenses, and seedling growth were complex. In general, defenses such as saponins and leaf toughness reduced herbivory, but when herbivory was high, seedling growth was reduced. Across treatments, mean height without herbivore damage was 240.8 cm, and with 50% herbivory mean height was 101.5 cm. Overall, to limit insect damage and promote seedling success, plant defense characteristics and ecological interactions should be carefully considered in reforestation projects.