Question: Have liana density and biomass increased in central Amazonia over the last 10 years? Ca... more Question: Have liana density and biomass increased in central Amazonia over the last 10 years? Can a spatially explicit consideration of liana mortality and recruitment rates across hydro-edaphic and tree turnover gradients at the landscape scale explain changes in liana density and biomass? Location: Ducke Forest Reserve, 26 km north of Manaus, Amazonas, Brazil. Methods: Data were collected on 30-1 ha permanent plots in a central Amazonia undisturbed old-growth rain forest 10 years after the first census. We measured lianas at 1.3 cm above their rooting point, with a diameter (D) ≥ 5 cm and subsampled lianas ≥1 cm diameter in 0.25 ha per plot. We estimated above-ground density and biomass changes, mortality rate, recruitment and diameter increase. Soil cations and available P were reduced to two dimensions with PCA and the first axis used as the descriptor of soil fertility. Height above the nearest drainage, a proxy for water availability, tree turnover (D ≥ 10 cm) and soil fertility were used as predictors of liana dynamics. Results: No significant change in liana density and biomass, averaged over the 30km 2 landscape, was observed over the last 10 years. In 2014, liana density was generally higher in more fertile soils, and it increased in areas closer to the water table and with higher tree turnover in the valleys. This pattern resulted from the higher liana recruitment rates in valley plots closer to the water table. Liana mortality rates were uniform across plots, similar among the diameter classes and, on average, higher than recruitment. Conclusion: We did not find any evidence that liana density and biomass have been increasing in this Neotropical site over the last 10 years. These findings suggest that the current knowledge on liana increase trends in the Neotropics should be reviewed if supported by further tropical studies. K E Y W O R D S above-ground biomass, central Amazonia, climbing ecology, liana mortality, liana recruitment, liana turnover, old-growth rain forest, tree turnover, vines 652 | Journal of Vegetation Science GEROLAMO Et AL.
Amazonia is extremely biodiverse, but the mechanisms for the origin of this diversity are still u... more Amazonia is extremely biodiverse, but the mechanisms for the origin of this diversity are still under debate. We propose a diversification model for Amazonia based on the interplay of intrinsic clade functional traits, habitat associations and past geological events, using as a model group the species-rich Neotropical family Marantaceae. Our results show that the species richness of the lineage is predicted by functional strategy, rather than clade age, and thus the fast vs. slow growth functional trade-off is a major determinant of clade diversification in Marantaceae. Rapidly growing clades were mostly associated with highly productive habitats, and their origin and diversification dynamics matched the expansion of fertile soils mediated by Andean uplift c. 23 Mya. Fast-growth strategies probably led to fast molecular evolution, speeding up speciation rates and species accumulation, resulting in higher numbers of extant species. Our results indicate that pure allopatric-dispersal ...
Central Amazon has been subjected to a higher frequency of extreme climatic events, such as very ... more Central Amazon has been subjected to a higher frequency of extreme climatic events, such as very dry or very wet years, in the last decades. Here, we report a 20-year monitoring of 6 biological groups over 100 km 2 of typical terra-firme forest at Ducke Forest Reserve, Manaus. Most assemblages had a decrease in abundance (9-35 %) and richness (8-25 %) along time, with some taxonomic and functional reorganization. Taxonomic and functional composition changes along time were more extensive in the valleys for trees and ants, and in first-order streams for fish; while bird and small trees had different patterns of composition change in valleys and plateaus. Although the signal of change was not congruent across all assemblages, patterns indicate that the forest and streams are becoming more dynamic as the hydrological cycle intensifies due to climate changes, and these new environments are already filtering species, at least in some well monitored taxonomic groups. Our data, in combination with other studies, suggest that riparian areas in the valleys are hydrological refuges during droughts, although also susceptible to disturbances induced by excessive precipitation and windstorms. In face of the importance of valleys as refuge, its sensibility and the unknown effects of potential migrations from higher topographic areas due to climate change, the
There is a consensus about negative impacts of droughts in Amazonia. Yet, extreme wet episodes,... more There is a consensus about negative impacts of droughts in Amazonia. Yet, extreme wet episodes, which are becoming as severe and frequent as droughts, are overlooked and their impacts remain poorly understood. Moreover, drought reports are mostly based on forests over a deep water table (DWT), which may be particularly sensitive to dry conditions. Based on demographic responses of 30 abundant tree species over the past two decades, in this study we analyzed the impacts of severe droughts but also of concurrent extreme wet periods, and how topographic affiliation (to shallow-SWTs-or deep-DWTs-water tables), together with species functional traits, mediated climate effects on trees. Dry and wet extremes decreased growth and increased tree mortality, but interactions of these climatic anomalies had the highest and most positive impact, mitigating the simple negative effects. Despite being more drought-tolerant, species in DWT forests were more negatively affected than hydraulically vulnerable species in SWT forests. Interaction of wet dry extremes and SWT depth modulated tree responses to climate, providing buffers to droughts in Amazonia. As extreme wet periods are projected to increase and at least 36% of the Amazon comprises SWT forests, our results highlight the importance of considering these factors in order to improve our knowledge about forest resilience to climate change.
Fourier Transformed Near-Infrared Spectroscopy (FT-NIR) has previously been shown to be effective... more Fourier Transformed Near-Infrared Spectroscopy (FT-NIR) has previously been shown to be effective in species discrimination of plant species, this prompted us to ask if higher taxonomic levels could also be discriminated, and if discrimination based on branch pieces would be equally efficient or better than based on leaves. We tested this with a sample of 384 branches and 349 leaves of 40 Amazonian species. We obtained spectral readings of dry branch and leaf material, and compared the rate of correct predictions of species, genera and family with a classifier based on Linear Discriminant Analysis (LDA). Discrimination of species, genus and family with Fourier Transformed Near-Infrared Spectroscopy (FT-NIR) was good using either branches or leaves. We obtained an average of 90.8% correct species identifications over all species based on branch FT-NIR profiles, and 94.1% based on leaves. Also, we obtained more than 95% correct genus and family identifications. Most of the identification errors occurred among species, genera and families of distinct clades. Near-infrared spectroscopy has great potential for discriminating species from branch samples and is suitable to discriminate a diverse range of genera and families of Amazonian trees.
Species distribution is strongly driven by local and global gradients in water availability but t... more Species distribution is strongly driven by local and global gradients in water availability but the underlying mechanisms are not clear. Vulnerability to xylem embolism (P ) is a key trait that indicates how species cope with drought and might explain plant distribution patterns across environmental gradients. Here we address its role on species sorting along a hydro-topographical gradient in a central Amazonian rainforest and examine its variance at the community scale. We measured P for 28 tree species, soil properties and estimated the hydrological niche of each species using an indicator of distance to the water table (HAND). We found a large hydraulic diversity, covering as much as 44% of the global angiosperm variation in P . We show that P : contributes to species segregation across a hydro-topographic gradient in the Amazon, and thus to species coexistence; is the result of repeated evolutionary adaptation within closely related taxa; is associated with species tolerance to ...
Ecological applications : a publication of the Ecological Society of America, Jan 16, 2018
The linking of individual functional traits to ecosystem processes is the basis for making genera... more The linking of individual functional traits to ecosystem processes is the basis for making generalizations in ecology, but the measurement of individual values is laborious and time consuming, preventing large-scale trait mapping. Also, in hyper-diverse systems, errors occur because identification is difficult, and species level values ignore intra-specific variation. To allow extensive trait mapping at the individual level, we evaluated the potential of Fourrier-Transformed Near Infra-Red Spectrometry (FT-NIR) to adequately describe 14 traits that are key for plant carbon, water, and nutrient balance. FT-NIR absorption spectra (1,000-2,500 nm) were obtained from dry leaves and branches of 1,324 trees of 432 species from a hyper-diverse Amazonian forest. FT-NIR spectra were related to measured traits for the same plants using partial least squares regressions. A further 80 plants were collected from a different site to evaluate model applicability across sites. Relative prediction e...
Species distributions and assemblage composition may be the result of trait selection through env... more Species distributions and assemblage composition may be the result of trait selection through environmental filters. Here, we ask whether filtering of species at the local scale could be attributed to their hydraulic architectural traits, revealing the basis of hydrological microhabitat partitioning in a Central Amazonian forest. We analyzed the hydraulic characteristics at tissue (anatomical traits, wood specific gravity (WSG)), organ (leaf area, specific leaf area (SLA), leaf area : sapwood area ratio) and whole-plant (height) levels for 28 pairs of congeneric species from 14 genera restricted to either valleys or plateaus of a terra-firme forest in Central Amazonia. On plateaus, species had higher WSG, but lower mean vessel area, mean vessel hydraulic diameter, sapwood area and SLA than in valleys; traits commonly associated with hydraulic safety. Mean vessel hydraulic diameter and mean vessel area increased with height for both habitats, but values were higher for plateau than f...
Among invertebrates, ants are the most abundant and probably most important seed dispersers in bo... more Among invertebrates, ants are the most abundant and probably most important seed dispersers in both temperate and tropical environments. Crickets, also abundant in tropical forests, are omnivores and commonly attracted to fruits on the forest floor. However, their capability to remove seeds has been reported only once. We compared Marantaceae seed removal by crickets and ants to assess the role of crickets as secondary seed dispersers in Amazonia. Compared with ants, crickets dispersed an equivalent number of seeds and tended to disperse larger seeds farther. However, seed removal by crickets occurs mostly at night, suggesting that removal of arillate seeds by crickets on the tropical forest floor is probably being overlooked or wrongly attributed to other invertebrate groups. One potential consequence of seed dispersal by crickets may be a change in the local spatial distribution of arillate-seed species, due to lower aggregation around ant nests.
We present a synthesis of the first 10 years of Long Term Ecological Research project in Amazonia... more We present a synthesis of the first 10 years of Long Term Ecological Research project in Amazonian Forest. We elucidate the natural dynamics of forest ecosystem processes and associated biota, and its changes caused by distinct pressures of selective timber extraction and forest fragmentation. We found that, for both plants and animals, densities of individuals and distribution of species assemblages are spatially heterogeneous at the mesoscale, even in relatively undisturbed forests, and that associations with topo-edaphic variables allow prediction of a considerable part of this variation. For biological groups whose dynamics were studied in the short-term, levels of change in species composition and densities were relatively high, and these changes were generally in tune with spatial environmental variation. The impact of selective logging on assemblages and ecosystem processes was normally moderate, and around 19 years were needed for recovering forest biomass and tree size distribution. Continued studies are needed to determine the time required for recuperation of timber stocks and pre-logging floristic composition. Selective logging appears to be compatible with the biodiversity conservation, but reduction and better planning of road access may be more important than planned logging intensities. Habitat-loss' impact on organisms and ecosystem processes is large and long-lasting, since it induces the loss of many taxonomic groups and species, higher tree mortality and accelerated forest dynamics. There was a negative synergy between the impacts of habitat loss and climatic changes, and a better understanding of these processes can only be obtained through long-term research.
Our objectives were to develop a method that would be appropriate for long-term ecological studie... more Our objectives were to develop a method that would be appropriate for long-term ecological studies, but that would permit rapid surveys to evaluate biotic complementarity and land-use planning in Amazonia. The Amazon basin covers about 7 million km². Therefore, even a sparse coverage, with one sample site per 10.000 km², would require about 700 sampling sites. Financial considerations limit the number of sites and investment at each site, but incomplete coverage makes evaluation of biotic complementarity difficult or impossible (Reddy & Dávalos 2003). Our next challenge is to install similar systems throughout Amazonia. The cost, based on modification of Al Gentry's original design is moderate (less than US$ 50.000 per site if it is not necessary to immediately identify all vascular plants in plots) and we can obtain RAP results for most taxa in the short term at much lower cost. However, biological surveys will only be relevant if the local people participate and the surveys se...
Brazilian Amazonia covers around 5 million km 2. If we could sample it regularly, with one sample... more Brazilian Amazonia covers around 5 million km 2. If we could sample it regularly, with one sample for each 1 degree cell (10,000 km 2), we would need 500 sample sites. It is clear that financial costs limit the amplitude of biodiversity studies. As the area to be explored is so large, financial resources limited, and demands varied, a program on Amazonian biodiversity research must be cost-effective. Integrated and large-scale studies, using standardized protocols represent the only way to achieve these goals. In this review, we report on experience gathered at two model sites in Amazonia, Reserva Ducke and Alter do Chão, which were used to design the RAPELD system, which is the principle basis for the Inventory Component of the Program on Biodiversity Research (PPBio) of the Brazilian government (http://ppbio.inpa.gov.br). We address the following issues: 1) how scale, size, shape and distribution of sampling units affect the outcome of biodiversity studies, in terms of the estimation of biotic complementarity between sites, estimation of organismal abundance, and modeling of species distributions; 2) how different sampling needs, from different taxonomic groups, can be adjusted in integrated protocols; 3) how costs can be reduced through sub-sampling. Use of the method in other research sites in Amazonia is being conducted successfully, and a large network of standardized plots is being constructed (see http://ppbio.inpa.gov.br). We also show that other methodologies currently used in large-scale biodiversity studies can be integrated into the RAPELD design.
A extensa área coberta pelo domínio amazônico e os recursos financeiros limitados para estudos da... more A extensa área coberta pelo domínio amazônico e os recursos financeiros limitados para estudos da biodiversidade exigem programas de pesquisa que obtenham o máximo de informação com os menores custos. Com o objetivo de avaliar as conseqüências da redução do esforço amostral sobre a retenção da informação ecológica, testou-se como diferentes larguras de parcela afetam os resultados da relação entre variação ambiental e composição da comunidade de pteridófitas da Amazônia Central. Foram feitas medidas da inclinação do terreno, abertura do dossel e do teor de argila do solo, em 37 parcelas de floresta de terra-firme. Todos os indivíduos de pteridófitas foram identificados e mapeados com relação a três faixas de amostragem. Foram testados os efeitos das variáveis ambientais sobre a composição de pteridófitas em parcelas de 250 x 2,5 m e em sub-amostras com a largura da parcela reduzida. A redução de 2,5 para 1 m na largura da parcela (60% de redução no esforço amostral) correspondeu a u...
The database of the Brazilian Program for Biodiversity Research (PPBio; GIVD ID SA-BR-001) includ... more The database of the Brazilian Program for Biodiversity Research (PPBio; GIVD ID SA-BR-001) includes data on the environment and biological groups such as plants. It is organized by site, which is usually a grid with 10 to 72 uniformly-distributed plots, and has already surveyed 1,638 relevés across different Brazilian ecosystems. The sampling design is based on the RAPELD system to allow integration of data from diverse taxa and ecosystem processes. RAPELD is a spatially-explicit sampling scheme to monitor biodiversity in long-term ecological research sites and during rapid appraisals of biodiversity that has attracted support from many management agencies, which are using it as their long-term monitoring system. Vegetation surveys include measurements of cover, biomass and number of individuals from woody and herbaceous vascular plants, along with environmental data. We have recently migrated to a metadata catalog and data repository which allows searching for specific groups across all sites. All RAPELD data have been collected since 2001, though the site also allows data from other long-term plots to be archived as associated projects.
This study aimed to determine the effects of canopy openness, litter depth, soil cation content a... more This study aimed to determine the effects of canopy openness, litter depth, soil cation content and texture on Piper assemblage composition at a mesoscale. Piper assemblage composition and environmental variables were inventoried in 41 0.125 ha (250 × 5 m) plots placed in a terra firme forest located in the Madeira-Purus interfluve, Central Amazonia. Ordination of the 41 plots by Non-metric Multidimensional Scaling (NMDS) in one dimension captured 58% of the floristic variation and was used as the response variable in multiple regression models. Environmental variables explained 39% of the variation in Piper assemblage composition, which was significantly related to litter depth, soil texture and canopy openness, but not to the cation content. Effects of edaphic components on plant assemblage structure have been reported for different plant groups, however the strong effect of litter depth at a mesoscale had not yet been demonstrated. We suggest that litter depth variation not only ...
Background: Plant composition changes with topography and edaphic gradients that correlate with s... more Background: Plant composition changes with topography and edaphic gradients that correlate with soil-water and nutrient availability. Data on soil water for the Amazon Basin are scarce, limiting the possibility of distinguishing between soil and soil-water influences on plant composition. Aim: We tested a new proxy for water table depth, the terrain height above nearest drainage (HAND), as a predictor of composition in trees, lianas, palms, shrubs, and herbs and compared HAND to conventional measures of height above sea level (HASL) and horizontal distances from nearest drainage (HDND). Methods: Plant-species composition in 72 plots distributed across 64 km 2 of lowland evergreen terra firme forest was summarised using non-metric multidimensional scaling (NMDS). NMDS scores were regressed against estimates of HAND, HASL and HDND. Results: Plant composition was highly correlated with the vertical distance from water table, capturing up to 82% of variation. All life forms showed highest turnover rates in the zone with seasonally water-saturated soils, which can extend 350 m from stream margins. Conclusions: Floristic composition is closely related to water table depth, and HAND appears to be the most robust available topographical metric of soil-water gradients. Brazilian conservation laws protecting 30-m-wide riparian buffers are likely to be too narrow to encompass the full zone of highest floristic turnover and may be ineffective in safeguarding riparian plant diversity.
There are few inventories of ferns and lycophytes of the Brazilian Amazon and most of them were m... more There are few inventories of ferns and lycophytes of the Brazilian Amazon and most of them were made in areas of poor soils. The general species richness found in previous studies is low. This study presents an annotated list containing 122 species and three varieties of ferns and lycophytes from Biological Reserve of Uatumã, a large reserve that includes small patches of rich soils in Central Amazonia. The study site is located ca. 200 km north of Manaus, AM, Brazil. Inventories were made more intensively inside a grid system of trails of 5 x 5 km and less intensively in some white-sand forests and waterfalls in the surroundings of Balbina´s Village. Reference to the original description, habit, habitat, material examined, geographic distribution and voucher information are presented for each taxon. This is the first floristic survey of ferns and lycophytes from areas with relatively rich soils of Central Amazonia. The high number of species found challenges the concept that Central Amazonia is species-poor for the two groups studied and the strong relationship with soil conditions reinforces the proposal to include ferns and lycophytes as indicator groups of the distribution of biodiversity in the region. RESUMO Poucos são os inventários de samambaias e licófitas feitos na Amazônia brasileira e a maioria destes foram feitos em áreas cujos solos são pobres em nutrientes. Não obstante, a riqueza de espécies encontrada em estudos prévios foi baixa. Neste estudo é apresentada uma lista anotada de 122 espécies e três variedades de samambaias e licófitas da Reserva Biológica do Uatumã, uma reserva grande em extensão e com pequenas manchas de solo rico na Amazônia Central. O estudo foi realizado a cerca de 200 km ao norte de Manaus, AM, Brasil. Os inventários foram mais intensos dentro de uma grade de trilhas de 5 x 5 km e com menor intensidade em áreas de campinas e campinaranas e em cachoeiras nos arredores da Vila de Balbina. Para cada táxon são apresentadas informações acerca do local da publicação original, hábito, habitat, material examinado, distribuição geográfica e voucher. Este é o primeiro estudo sobre samambaias e licófitas em áreas com solos relativamente ricos na Amazônia FERN GAZ. 18(6):286-306. 2009 286 Central. A alta riqueza de espécies encontrada afeta a idéia geral de que a Amazônia Central é pobre em espécies destes dois grupos e a forte relação entre as espécies e as condições do solo reforça a sugestão de se incluir samambaias e licófitas como grupos indicadores da distribuição da biodiversidade.
Aim: A major problem for conservation in Amazonia is that species distribution maps are inaccurat... more Aim: A major problem for conservation in Amazonia is that species distribution maps are inaccurate. Consequently, conservation planning needs to be based on other information sources such as vegetation and soil maps, which are also inaccurate. We propose and test the use of biotic data on a common and relatively easily inventoried group of plants to infer environmental conditions that can be used to improve maps of floristic patterns for plants in general. Location: Brazilian Amazonia. Methods: We sampled 326 plots of 250 m 9 2 m separated by distances of 1-1800 km. Terrestrial fern individuals were identified and counted. Edaphic data were obtained from soil samples and analysed for cation concentration and texture. Climatic data were obtained from Worldclim. We used a multivariate regression tree to evaluate the hierarchical importance of soils and climate for fern communities and identified significant indicator species for the resultant classification. We then tested how well the edaphic properties of the plots could be predicted on the basis of their floristic composition using two calibration methods, weighted averaging and k-nearest neighbour estimation. Results: Soil cation concentration emerged as the most important variable in the regression tree, whereas soil textural and climatic variation played secondary roles. Almost all the plot classes had several fern species with high indicator values for that class. Soil cation concentration was also the variable most accurately predicted on the basis of fern community composition (R 2 = 0.65-0.75 for log-transformed data). Predictive accuracy varied little among the calibration methods, and was not improved by the use of abundance data instead of presence-absence data. Conclusions: Fern species composition can be used as an indicator of soil cation concentration, which can be expected to be relevant also for other components of rain forests. Presence-absence data are adequate for this purpose, which makes the collecting of additional data potentially very rapid. Comparison with earlier studies suggests that edaphic preferences of fern species have good transferability across geographical regions within lowland Amazonia. Therefore, species and environmental data sets already available in the Amazon region represent a good starting point for generating better environmental and floristic maps for conservation planning.
1 Many authors have suggested that topography and soils are the major determinants of species dis... more 1 Many authors have suggested that topography and soils are the major determinants of species distributions and community patterns at small or regional scales, but few studies addressed the patterns at mesoscales. We used Reserva Ducke (100 km 2) as a model to analyse the effects of soil, topography and watersheds on the variation of the herb community composition, and to determine the relative importance of the environmental factors on species composition. 2 Taxonomic groups are frequently used as surrogates in studies of biodiversity distribution and complementarity, but their efficacy is controversial. We therefore studied the correlations between the distributional patterns of three different herb groups (Marantaceae, pteridophytes and 'others') and their responses to environmental predictors. 3 Terrestrial herbs were sampled in 59 plots of 250 × 2 m, systematically distributed over the reserve. Plots followed isoclines of altitude, to minimize the internal variation of soil. Composition of the total herb community and of the three herb groups was summarized with PCoA. 4 Soil structure, represented by PCA axes, was the main determinant of the variation in herb composition for all groups, but slope affected only pteridophytes. Soil and topography explained less than one-third of the variance in community data. Herb composition was significantly different between watersheds, but watersheds differ only slightly in soil parameters. Our results indicate high turnover in species composition, on spatial scales of 5-10 km in central Amazonia, which is not necessarily associated with soil change. 5 Compositional patterns of the three groups analysed were significantly correlated, but with low values for the correlation coefficient. Although composition was correlated, the responses to environmental predictors differed among groups, and the use of one group as a surrogate will miss around 50% of the variation in other groups. 6 Although important, soil and topography alone cannot predict herb community structure. Knowledge of geographical, historical or other landscape features, such as watershed morphology, may therefore be necessary to predict the turnover patterns over mesoscales. Moreover, the same factors may not have the same effectiveness as predictors of the structure of seemingly similar biological groups.
Habitat availability for larval development is one of the main factors affecting the distribution... more Habitat availability for larval development is one of the main factors affecting the distribution of anuran species. However, little is known about the spatial distribution of these habitats, and estimates of the number of available ponds for a given reserve size are not available in Amazonia. Temporary water bodies were surveyed in a 30-m strip around a 144-km system of trails in a terra firme tropical forest, and tadpoles were collected to evaluate differences in species composition between isolated and streamside ponds. More than 90% of the ponds were ,150 m from a stream, and the tadpole species composition differed between isolated and streamside ponds. Isolated ponds were less common, but were, on average, more stable in time than streamside ponds. Despite the limited distribution of isolated forest ponds, species of frogs dependent on them were found throughout the reserve. The presence of both types of ponds is important for the maintenance of the local pond-breeding anuran community. This study shows that isolated and streamside forest ponds maintain a distinct assemblage of frogs, and isolated ponds are much less common, but are, on average, more predictable in time than streamside ponds.
Question: Have liana density and biomass increased in central Amazonia over the last 10 years? Ca... more Question: Have liana density and biomass increased in central Amazonia over the last 10 years? Can a spatially explicit consideration of liana mortality and recruitment rates across hydro-edaphic and tree turnover gradients at the landscape scale explain changes in liana density and biomass? Location: Ducke Forest Reserve, 26 km north of Manaus, Amazonas, Brazil. Methods: Data were collected on 30-1 ha permanent plots in a central Amazonia undisturbed old-growth rain forest 10 years after the first census. We measured lianas at 1.3 cm above their rooting point, with a diameter (D) ≥ 5 cm and subsampled lianas ≥1 cm diameter in 0.25 ha per plot. We estimated above-ground density and biomass changes, mortality rate, recruitment and diameter increase. Soil cations and available P were reduced to two dimensions with PCA and the first axis used as the descriptor of soil fertility. Height above the nearest drainage, a proxy for water availability, tree turnover (D ≥ 10 cm) and soil fertility were used as predictors of liana dynamics. Results: No significant change in liana density and biomass, averaged over the 30km 2 landscape, was observed over the last 10 years. In 2014, liana density was generally higher in more fertile soils, and it increased in areas closer to the water table and with higher tree turnover in the valleys. This pattern resulted from the higher liana recruitment rates in valley plots closer to the water table. Liana mortality rates were uniform across plots, similar among the diameter classes and, on average, higher than recruitment. Conclusion: We did not find any evidence that liana density and biomass have been increasing in this Neotropical site over the last 10 years. These findings suggest that the current knowledge on liana increase trends in the Neotropics should be reviewed if supported by further tropical studies. K E Y W O R D S above-ground biomass, central Amazonia, climbing ecology, liana mortality, liana recruitment, liana turnover, old-growth rain forest, tree turnover, vines 652 | Journal of Vegetation Science GEROLAMO Et AL.
Amazonia is extremely biodiverse, but the mechanisms for the origin of this diversity are still u... more Amazonia is extremely biodiverse, but the mechanisms for the origin of this diversity are still under debate. We propose a diversification model for Amazonia based on the interplay of intrinsic clade functional traits, habitat associations and past geological events, using as a model group the species-rich Neotropical family Marantaceae. Our results show that the species richness of the lineage is predicted by functional strategy, rather than clade age, and thus the fast vs. slow growth functional trade-off is a major determinant of clade diversification in Marantaceae. Rapidly growing clades were mostly associated with highly productive habitats, and their origin and diversification dynamics matched the expansion of fertile soils mediated by Andean uplift c. 23 Mya. Fast-growth strategies probably led to fast molecular evolution, speeding up speciation rates and species accumulation, resulting in higher numbers of extant species. Our results indicate that pure allopatric-dispersal ...
Central Amazon has been subjected to a higher frequency of extreme climatic events, such as very ... more Central Amazon has been subjected to a higher frequency of extreme climatic events, such as very dry or very wet years, in the last decades. Here, we report a 20-year monitoring of 6 biological groups over 100 km 2 of typical terra-firme forest at Ducke Forest Reserve, Manaus. Most assemblages had a decrease in abundance (9-35 %) and richness (8-25 %) along time, with some taxonomic and functional reorganization. Taxonomic and functional composition changes along time were more extensive in the valleys for trees and ants, and in first-order streams for fish; while bird and small trees had different patterns of composition change in valleys and plateaus. Although the signal of change was not congruent across all assemblages, patterns indicate that the forest and streams are becoming more dynamic as the hydrological cycle intensifies due to climate changes, and these new environments are already filtering species, at least in some well monitored taxonomic groups. Our data, in combination with other studies, suggest that riparian areas in the valleys are hydrological refuges during droughts, although also susceptible to disturbances induced by excessive precipitation and windstorms. In face of the importance of valleys as refuge, its sensibility and the unknown effects of potential migrations from higher topographic areas due to climate change, the
There is a consensus about negative impacts of droughts in Amazonia. Yet, extreme wet episodes,... more There is a consensus about negative impacts of droughts in Amazonia. Yet, extreme wet episodes, which are becoming as severe and frequent as droughts, are overlooked and their impacts remain poorly understood. Moreover, drought reports are mostly based on forests over a deep water table (DWT), which may be particularly sensitive to dry conditions. Based on demographic responses of 30 abundant tree species over the past two decades, in this study we analyzed the impacts of severe droughts but also of concurrent extreme wet periods, and how topographic affiliation (to shallow-SWTs-or deep-DWTs-water tables), together with species functional traits, mediated climate effects on trees. Dry and wet extremes decreased growth and increased tree mortality, but interactions of these climatic anomalies had the highest and most positive impact, mitigating the simple negative effects. Despite being more drought-tolerant, species in DWT forests were more negatively affected than hydraulically vulnerable species in SWT forests. Interaction of wet dry extremes and SWT depth modulated tree responses to climate, providing buffers to droughts in Amazonia. As extreme wet periods are projected to increase and at least 36% of the Amazon comprises SWT forests, our results highlight the importance of considering these factors in order to improve our knowledge about forest resilience to climate change.
Fourier Transformed Near-Infrared Spectroscopy (FT-NIR) has previously been shown to be effective... more Fourier Transformed Near-Infrared Spectroscopy (FT-NIR) has previously been shown to be effective in species discrimination of plant species, this prompted us to ask if higher taxonomic levels could also be discriminated, and if discrimination based on branch pieces would be equally efficient or better than based on leaves. We tested this with a sample of 384 branches and 349 leaves of 40 Amazonian species. We obtained spectral readings of dry branch and leaf material, and compared the rate of correct predictions of species, genera and family with a classifier based on Linear Discriminant Analysis (LDA). Discrimination of species, genus and family with Fourier Transformed Near-Infrared Spectroscopy (FT-NIR) was good using either branches or leaves. We obtained an average of 90.8% correct species identifications over all species based on branch FT-NIR profiles, and 94.1% based on leaves. Also, we obtained more than 95% correct genus and family identifications. Most of the identification errors occurred among species, genera and families of distinct clades. Near-infrared spectroscopy has great potential for discriminating species from branch samples and is suitable to discriminate a diverse range of genera and families of Amazonian trees.
Species distribution is strongly driven by local and global gradients in water availability but t... more Species distribution is strongly driven by local and global gradients in water availability but the underlying mechanisms are not clear. Vulnerability to xylem embolism (P ) is a key trait that indicates how species cope with drought and might explain plant distribution patterns across environmental gradients. Here we address its role on species sorting along a hydro-topographical gradient in a central Amazonian rainforest and examine its variance at the community scale. We measured P for 28 tree species, soil properties and estimated the hydrological niche of each species using an indicator of distance to the water table (HAND). We found a large hydraulic diversity, covering as much as 44% of the global angiosperm variation in P . We show that P : contributes to species segregation across a hydro-topographic gradient in the Amazon, and thus to species coexistence; is the result of repeated evolutionary adaptation within closely related taxa; is associated with species tolerance to ...
Ecological applications : a publication of the Ecological Society of America, Jan 16, 2018
The linking of individual functional traits to ecosystem processes is the basis for making genera... more The linking of individual functional traits to ecosystem processes is the basis for making generalizations in ecology, but the measurement of individual values is laborious and time consuming, preventing large-scale trait mapping. Also, in hyper-diverse systems, errors occur because identification is difficult, and species level values ignore intra-specific variation. To allow extensive trait mapping at the individual level, we evaluated the potential of Fourrier-Transformed Near Infra-Red Spectrometry (FT-NIR) to adequately describe 14 traits that are key for plant carbon, water, and nutrient balance. FT-NIR absorption spectra (1,000-2,500 nm) were obtained from dry leaves and branches of 1,324 trees of 432 species from a hyper-diverse Amazonian forest. FT-NIR spectra were related to measured traits for the same plants using partial least squares regressions. A further 80 plants were collected from a different site to evaluate model applicability across sites. Relative prediction e...
Species distributions and assemblage composition may be the result of trait selection through env... more Species distributions and assemblage composition may be the result of trait selection through environmental filters. Here, we ask whether filtering of species at the local scale could be attributed to their hydraulic architectural traits, revealing the basis of hydrological microhabitat partitioning in a Central Amazonian forest. We analyzed the hydraulic characteristics at tissue (anatomical traits, wood specific gravity (WSG)), organ (leaf area, specific leaf area (SLA), leaf area : sapwood area ratio) and whole-plant (height) levels for 28 pairs of congeneric species from 14 genera restricted to either valleys or plateaus of a terra-firme forest in Central Amazonia. On plateaus, species had higher WSG, but lower mean vessel area, mean vessel hydraulic diameter, sapwood area and SLA than in valleys; traits commonly associated with hydraulic safety. Mean vessel hydraulic diameter and mean vessel area increased with height for both habitats, but values were higher for plateau than f...
Among invertebrates, ants are the most abundant and probably most important seed dispersers in bo... more Among invertebrates, ants are the most abundant and probably most important seed dispersers in both temperate and tropical environments. Crickets, also abundant in tropical forests, are omnivores and commonly attracted to fruits on the forest floor. However, their capability to remove seeds has been reported only once. We compared Marantaceae seed removal by crickets and ants to assess the role of crickets as secondary seed dispersers in Amazonia. Compared with ants, crickets dispersed an equivalent number of seeds and tended to disperse larger seeds farther. However, seed removal by crickets occurs mostly at night, suggesting that removal of arillate seeds by crickets on the tropical forest floor is probably being overlooked or wrongly attributed to other invertebrate groups. One potential consequence of seed dispersal by crickets may be a change in the local spatial distribution of arillate-seed species, due to lower aggregation around ant nests.
We present a synthesis of the first 10 years of Long Term Ecological Research project in Amazonia... more We present a synthesis of the first 10 years of Long Term Ecological Research project in Amazonian Forest. We elucidate the natural dynamics of forest ecosystem processes and associated biota, and its changes caused by distinct pressures of selective timber extraction and forest fragmentation. We found that, for both plants and animals, densities of individuals and distribution of species assemblages are spatially heterogeneous at the mesoscale, even in relatively undisturbed forests, and that associations with topo-edaphic variables allow prediction of a considerable part of this variation. For biological groups whose dynamics were studied in the short-term, levels of change in species composition and densities were relatively high, and these changes were generally in tune with spatial environmental variation. The impact of selective logging on assemblages and ecosystem processes was normally moderate, and around 19 years were needed for recovering forest biomass and tree size distribution. Continued studies are needed to determine the time required for recuperation of timber stocks and pre-logging floristic composition. Selective logging appears to be compatible with the biodiversity conservation, but reduction and better planning of road access may be more important than planned logging intensities. Habitat-loss' impact on organisms and ecosystem processes is large and long-lasting, since it induces the loss of many taxonomic groups and species, higher tree mortality and accelerated forest dynamics. There was a negative synergy between the impacts of habitat loss and climatic changes, and a better understanding of these processes can only be obtained through long-term research.
Our objectives were to develop a method that would be appropriate for long-term ecological studie... more Our objectives were to develop a method that would be appropriate for long-term ecological studies, but that would permit rapid surveys to evaluate biotic complementarity and land-use planning in Amazonia. The Amazon basin covers about 7 million km². Therefore, even a sparse coverage, with one sample site per 10.000 km², would require about 700 sampling sites. Financial considerations limit the number of sites and investment at each site, but incomplete coverage makes evaluation of biotic complementarity difficult or impossible (Reddy & Dávalos 2003). Our next challenge is to install similar systems throughout Amazonia. The cost, based on modification of Al Gentry's original design is moderate (less than US$ 50.000 per site if it is not necessary to immediately identify all vascular plants in plots) and we can obtain RAP results for most taxa in the short term at much lower cost. However, biological surveys will only be relevant if the local people participate and the surveys se...
Brazilian Amazonia covers around 5 million km 2. If we could sample it regularly, with one sample... more Brazilian Amazonia covers around 5 million km 2. If we could sample it regularly, with one sample for each 1 degree cell (10,000 km 2), we would need 500 sample sites. It is clear that financial costs limit the amplitude of biodiversity studies. As the area to be explored is so large, financial resources limited, and demands varied, a program on Amazonian biodiversity research must be cost-effective. Integrated and large-scale studies, using standardized protocols represent the only way to achieve these goals. In this review, we report on experience gathered at two model sites in Amazonia, Reserva Ducke and Alter do Chão, which were used to design the RAPELD system, which is the principle basis for the Inventory Component of the Program on Biodiversity Research (PPBio) of the Brazilian government (http://ppbio.inpa.gov.br). We address the following issues: 1) how scale, size, shape and distribution of sampling units affect the outcome of biodiversity studies, in terms of the estimation of biotic complementarity between sites, estimation of organismal abundance, and modeling of species distributions; 2) how different sampling needs, from different taxonomic groups, can be adjusted in integrated protocols; 3) how costs can be reduced through sub-sampling. Use of the method in other research sites in Amazonia is being conducted successfully, and a large network of standardized plots is being constructed (see http://ppbio.inpa.gov.br). We also show that other methodologies currently used in large-scale biodiversity studies can be integrated into the RAPELD design.
A extensa área coberta pelo domínio amazônico e os recursos financeiros limitados para estudos da... more A extensa área coberta pelo domínio amazônico e os recursos financeiros limitados para estudos da biodiversidade exigem programas de pesquisa que obtenham o máximo de informação com os menores custos. Com o objetivo de avaliar as conseqüências da redução do esforço amostral sobre a retenção da informação ecológica, testou-se como diferentes larguras de parcela afetam os resultados da relação entre variação ambiental e composição da comunidade de pteridófitas da Amazônia Central. Foram feitas medidas da inclinação do terreno, abertura do dossel e do teor de argila do solo, em 37 parcelas de floresta de terra-firme. Todos os indivíduos de pteridófitas foram identificados e mapeados com relação a três faixas de amostragem. Foram testados os efeitos das variáveis ambientais sobre a composição de pteridófitas em parcelas de 250 x 2,5 m e em sub-amostras com a largura da parcela reduzida. A redução de 2,5 para 1 m na largura da parcela (60% de redução no esforço amostral) correspondeu a u...
The database of the Brazilian Program for Biodiversity Research (PPBio; GIVD ID SA-BR-001) includ... more The database of the Brazilian Program for Biodiversity Research (PPBio; GIVD ID SA-BR-001) includes data on the environment and biological groups such as plants. It is organized by site, which is usually a grid with 10 to 72 uniformly-distributed plots, and has already surveyed 1,638 relevés across different Brazilian ecosystems. The sampling design is based on the RAPELD system to allow integration of data from diverse taxa and ecosystem processes. RAPELD is a spatially-explicit sampling scheme to monitor biodiversity in long-term ecological research sites and during rapid appraisals of biodiversity that has attracted support from many management agencies, which are using it as their long-term monitoring system. Vegetation surveys include measurements of cover, biomass and number of individuals from woody and herbaceous vascular plants, along with environmental data. We have recently migrated to a metadata catalog and data repository which allows searching for specific groups across all sites. All RAPELD data have been collected since 2001, though the site also allows data from other long-term plots to be archived as associated projects.
This study aimed to determine the effects of canopy openness, litter depth, soil cation content a... more This study aimed to determine the effects of canopy openness, litter depth, soil cation content and texture on Piper assemblage composition at a mesoscale. Piper assemblage composition and environmental variables were inventoried in 41 0.125 ha (250 × 5 m) plots placed in a terra firme forest located in the Madeira-Purus interfluve, Central Amazonia. Ordination of the 41 plots by Non-metric Multidimensional Scaling (NMDS) in one dimension captured 58% of the floristic variation and was used as the response variable in multiple regression models. Environmental variables explained 39% of the variation in Piper assemblage composition, which was significantly related to litter depth, soil texture and canopy openness, but not to the cation content. Effects of edaphic components on plant assemblage structure have been reported for different plant groups, however the strong effect of litter depth at a mesoscale had not yet been demonstrated. We suggest that litter depth variation not only ...
Background: Plant composition changes with topography and edaphic gradients that correlate with s... more Background: Plant composition changes with topography and edaphic gradients that correlate with soil-water and nutrient availability. Data on soil water for the Amazon Basin are scarce, limiting the possibility of distinguishing between soil and soil-water influences on plant composition. Aim: We tested a new proxy for water table depth, the terrain height above nearest drainage (HAND), as a predictor of composition in trees, lianas, palms, shrubs, and herbs and compared HAND to conventional measures of height above sea level (HASL) and horizontal distances from nearest drainage (HDND). Methods: Plant-species composition in 72 plots distributed across 64 km 2 of lowland evergreen terra firme forest was summarised using non-metric multidimensional scaling (NMDS). NMDS scores were regressed against estimates of HAND, HASL and HDND. Results: Plant composition was highly correlated with the vertical distance from water table, capturing up to 82% of variation. All life forms showed highest turnover rates in the zone with seasonally water-saturated soils, which can extend 350 m from stream margins. Conclusions: Floristic composition is closely related to water table depth, and HAND appears to be the most robust available topographical metric of soil-water gradients. Brazilian conservation laws protecting 30-m-wide riparian buffers are likely to be too narrow to encompass the full zone of highest floristic turnover and may be ineffective in safeguarding riparian plant diversity.
There are few inventories of ferns and lycophytes of the Brazilian Amazon and most of them were m... more There are few inventories of ferns and lycophytes of the Brazilian Amazon and most of them were made in areas of poor soils. The general species richness found in previous studies is low. This study presents an annotated list containing 122 species and three varieties of ferns and lycophytes from Biological Reserve of Uatumã, a large reserve that includes small patches of rich soils in Central Amazonia. The study site is located ca. 200 km north of Manaus, AM, Brazil. Inventories were made more intensively inside a grid system of trails of 5 x 5 km and less intensively in some white-sand forests and waterfalls in the surroundings of Balbina´s Village. Reference to the original description, habit, habitat, material examined, geographic distribution and voucher information are presented for each taxon. This is the first floristic survey of ferns and lycophytes from areas with relatively rich soils of Central Amazonia. The high number of species found challenges the concept that Central Amazonia is species-poor for the two groups studied and the strong relationship with soil conditions reinforces the proposal to include ferns and lycophytes as indicator groups of the distribution of biodiversity in the region. RESUMO Poucos são os inventários de samambaias e licófitas feitos na Amazônia brasileira e a maioria destes foram feitos em áreas cujos solos são pobres em nutrientes. Não obstante, a riqueza de espécies encontrada em estudos prévios foi baixa. Neste estudo é apresentada uma lista anotada de 122 espécies e três variedades de samambaias e licófitas da Reserva Biológica do Uatumã, uma reserva grande em extensão e com pequenas manchas de solo rico na Amazônia Central. O estudo foi realizado a cerca de 200 km ao norte de Manaus, AM, Brasil. Os inventários foram mais intensos dentro de uma grade de trilhas de 5 x 5 km e com menor intensidade em áreas de campinas e campinaranas e em cachoeiras nos arredores da Vila de Balbina. Para cada táxon são apresentadas informações acerca do local da publicação original, hábito, habitat, material examinado, distribuição geográfica e voucher. Este é o primeiro estudo sobre samambaias e licófitas em áreas com solos relativamente ricos na Amazônia FERN GAZ. 18(6):286-306. 2009 286 Central. A alta riqueza de espécies encontrada afeta a idéia geral de que a Amazônia Central é pobre em espécies destes dois grupos e a forte relação entre as espécies e as condições do solo reforça a sugestão de se incluir samambaias e licófitas como grupos indicadores da distribuição da biodiversidade.
Aim: A major problem for conservation in Amazonia is that species distribution maps are inaccurat... more Aim: A major problem for conservation in Amazonia is that species distribution maps are inaccurate. Consequently, conservation planning needs to be based on other information sources such as vegetation and soil maps, which are also inaccurate. We propose and test the use of biotic data on a common and relatively easily inventoried group of plants to infer environmental conditions that can be used to improve maps of floristic patterns for plants in general. Location: Brazilian Amazonia. Methods: We sampled 326 plots of 250 m 9 2 m separated by distances of 1-1800 km. Terrestrial fern individuals were identified and counted. Edaphic data were obtained from soil samples and analysed for cation concentration and texture. Climatic data were obtained from Worldclim. We used a multivariate regression tree to evaluate the hierarchical importance of soils and climate for fern communities and identified significant indicator species for the resultant classification. We then tested how well the edaphic properties of the plots could be predicted on the basis of their floristic composition using two calibration methods, weighted averaging and k-nearest neighbour estimation. Results: Soil cation concentration emerged as the most important variable in the regression tree, whereas soil textural and climatic variation played secondary roles. Almost all the plot classes had several fern species with high indicator values for that class. Soil cation concentration was also the variable most accurately predicted on the basis of fern community composition (R 2 = 0.65-0.75 for log-transformed data). Predictive accuracy varied little among the calibration methods, and was not improved by the use of abundance data instead of presence-absence data. Conclusions: Fern species composition can be used as an indicator of soil cation concentration, which can be expected to be relevant also for other components of rain forests. Presence-absence data are adequate for this purpose, which makes the collecting of additional data potentially very rapid. Comparison with earlier studies suggests that edaphic preferences of fern species have good transferability across geographical regions within lowland Amazonia. Therefore, species and environmental data sets already available in the Amazon region represent a good starting point for generating better environmental and floristic maps for conservation planning.
1 Many authors have suggested that topography and soils are the major determinants of species dis... more 1 Many authors have suggested that topography and soils are the major determinants of species distributions and community patterns at small or regional scales, but few studies addressed the patterns at mesoscales. We used Reserva Ducke (100 km 2) as a model to analyse the effects of soil, topography and watersheds on the variation of the herb community composition, and to determine the relative importance of the environmental factors on species composition. 2 Taxonomic groups are frequently used as surrogates in studies of biodiversity distribution and complementarity, but their efficacy is controversial. We therefore studied the correlations between the distributional patterns of three different herb groups (Marantaceae, pteridophytes and 'others') and their responses to environmental predictors. 3 Terrestrial herbs were sampled in 59 plots of 250 × 2 m, systematically distributed over the reserve. Plots followed isoclines of altitude, to minimize the internal variation of soil. Composition of the total herb community and of the three herb groups was summarized with PCoA. 4 Soil structure, represented by PCA axes, was the main determinant of the variation in herb composition for all groups, but slope affected only pteridophytes. Soil and topography explained less than one-third of the variance in community data. Herb composition was significantly different between watersheds, but watersheds differ only slightly in soil parameters. Our results indicate high turnover in species composition, on spatial scales of 5-10 km in central Amazonia, which is not necessarily associated with soil change. 5 Compositional patterns of the three groups analysed were significantly correlated, but with low values for the correlation coefficient. Although composition was correlated, the responses to environmental predictors differed among groups, and the use of one group as a surrogate will miss around 50% of the variation in other groups. 6 Although important, soil and topography alone cannot predict herb community structure. Knowledge of geographical, historical or other landscape features, such as watershed morphology, may therefore be necessary to predict the turnover patterns over mesoscales. Moreover, the same factors may not have the same effectiveness as predictors of the structure of seemingly similar biological groups.
Habitat availability for larval development is one of the main factors affecting the distribution... more Habitat availability for larval development is one of the main factors affecting the distribution of anuran species. However, little is known about the spatial distribution of these habitats, and estimates of the number of available ponds for a given reserve size are not available in Amazonia. Temporary water bodies were surveyed in a 30-m strip around a 144-km system of trails in a terra firme tropical forest, and tadpoles were collected to evaluate differences in species composition between isolated and streamside ponds. More than 90% of the ponds were ,150 m from a stream, and the tadpole species composition differed between isolated and streamside ponds. Isolated ponds were less common, but were, on average, more stable in time than streamside ponds. Despite the limited distribution of isolated forest ponds, species of frogs dependent on them were found throughout the reserve. The presence of both types of ponds is important for the maintenance of the local pond-breeding anuran community. This study shows that isolated and streamside forest ponds maintain a distinct assemblage of frogs, and isolated ponds are much less common, but are, on average, more predictable in time than streamside ponds.
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