High tree alpha-diversity in Amazonian Ecuador

Valencia, Renato; Balslev, Henrik

doi:10.1007/bf00115330

Cited by 331 publications

(214 citation statements)

References 12 publications

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“…Biodiversity studies in North West Amazon forests have focused mainly on plants, especially tree species (Gentry 1988a;Duivenvoorden 1996;Pitman et al 2001;Condit et al 2002) and revealed that these forests hold a very high number of plant species (Gentry 1988a;Valencia et al 1994;Rudas and Prieto 1998;Ter Steege et al 2003;Duque 2004;Hoorn et al 2010). Despite this extensive plant and animal biodiversity, the region is not yet recognized as a biodiversity hotspot (Myers et al 2000) (http://www.biodiversityhotspots.org/xp/Hotspots/hotspots_by_region/Pages/default.aspx December 2009).…”

Section: Introductionmentioning

confidence: 99%

Macrofungal diversity in Colombian Amazon forests varies with regions and regimes of disturbance

et al. 2012

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Here we present the results of fungal biodiversity studies from some selected Colombian Amazon forests in relationship to plant biodiversity and successional stages after slash and burn agriculture. Macrofungal diversity was found to differ between forests occurring in two regions (Araracuara vs Amacayacu) as well as between flooded forests and terra firme forests in the Amacayacu region. Macrofungal biodiversity differed between regeneration states of different age in the Araracuara region. Suitable substrates, especially dead wood that occurred as a result of recent slash and burn agriculture, resulted in the formation of many sporocarps of wood-inhabiting species. Putative ectomycorrhizal species were found in a dipterocarp forest. Fifty two percent of the macrofungal species could not be identified to the species level, but could be assigned to a genus, and it is likely that a significant portion of these represent species new to science. Long term studies are needed to obtain a comprehensive and complete understanding of the diversity and functioning of mycobiota in Amazon forest ecosystems.

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Section: Introductionmentioning

confidence: 99%

Macrofungal diversity in Colombian Amazon forests varies with regions and regimes of disturbance

et al. 2012

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“…Three-quarters of our rainforest soil protist data would be discarded if we applied this conservative cleaning step. Furthermore, PR 2 and similar databases are biased towards marine and temperate references. To solve these problems, reads were dereplicated into 10.6 million amplicons (strictly identical reads to which an abundance value can be attached), and subsequently placed using the Evolutionary Placement Algorithm (EPA) 14 , as implemented in RAxML 15 , onto a phylogenetic tree inferred from 512 full-length references from all major eukaryotic clades ( Fig.…”

Section: Resultsmentioning

confidence: 99%

“…For example, one hectare can contain more than 400 tree species 2 and one tree can harbour more than 40 ant species 3 . This hyperdiversity of trees has been partially explained by the Janzen-Connell model 4,5 , which hypothesizes that host-specific predators and parasites reduce plant population growth in a density-dependent manner 6,7 .…”

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confidence: 99%

Parasites dominate hyperdiverse soil protist communities in Neotropical rainforests

et al. 2017

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High animal and plant richness in tropical rainforest communities has long intrigued naturalists. It is unknown if similar hyperdiversity patterns are reflected at the microbial scale with unicellular eukaryotes (protists). Here we show, using environmental metabarcoding of soil samples and a phylogeny-aware cleaning step, that protist communities in Neotropical rainforests are hyperdiverse and dominated by the parasitic Apicomplexa, which infect arthropods and other animals. These host-specific parasites potentially contribute to the high animal diversity in the forests by reducing population growth in a density-dependent manner. By contrast, too few operational taxonomic units (OTUs) of Oomycota were found to broadly drive high tropical tree diversity in a host-specific manner under the Janzen-Connell model. Extremely high OTU diversity and high heterogeneity between samples within the same forests suggest that protists, not arthropods, are the most diverse eukaryotes in tropical rainforests. Our data show that protists play a large role in tropical terrestrial ecosystems long viewed as being dominated by macroorganisms.S ince the works of early naturalists such as von Humboldt and Bonpland 1 , we have known that animal and plant communities in tropical rainforests are exceedingly species rich. For example, one hectare can contain more than 400 tree species 2 and one tree can harbour more than 40 ant species 3 . This hyperdiversity of trees has been partially explained by the Janzen-Connell model 4,5 , which hypothesizes that host-specific predators and parasites reduce plant population growth in a density-dependent manner 6,7 . Sampling up in the tree canopies and below on the ground has further led to the view that arthropods are the most diverse eukaryotes in tropical rainforests 8,9 .The focus on eukaryotic macroorganisms in these studies is primarily because they are familiar and readily observable to us. We do not know whether the less familiar and less readily observable protists-microbial eukaryotes that are not animals, plants or fungi 10 -inhabiting these same ecosystems exhibit similar diversity patterns. To evaluate if macroorganismic diversity patterns are reflected at the microbial scale with protists, we conducted an environmental DNA metabarcoding study by sampling soils in 279 locations in a variety of lowland Neotropical forest types in La Selva Biological Station, Costa Rica, Barro Colorado Island, Panama and Tiputini Biodiversity Station, Ecuador. This metabarcoding approach has the power to uncover known and new taxa on a massive scale 11 . By amplifying DNA extracted from the soils with broadly targeted primers for the V4 region of 18S rRNA and sequencing it using the Illumina MiSeq platform, we were able to detect most eukaryotic lineages, and assess the diversity and relative dominance of free-living and parasitic lineages.

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“…Também apresentou baixa diversidade beta, considerando que esta reflete o grau de mudança na composição de espécies ao longo de um gradiente, pois o índice de diversidade para a área total manteve-se em 3,86. Na Amazônia, a riqueza de espécies arbóreas atinge valores desde 87 espécies por hectare no leste (Pires, 1957) a até 300 espécies por hectare no oeste (Gentry, 1988;Valencia et al, 1994;Oliveira, 1997), para árvores com DAP > 10cm. Também foi registrado maior número de espécies no centro e noroeste da Amazônia, do que nas partes orientais e ocidentais da região (Ducke & Black, 1954;.…”

Section: Continuação Da Tabelaunclassified

Estrutura de um trecho de floresta Amazônica na bacia do alto rio Xingu

2004

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RESUMOEste estudo apresenta a estrutura de florestas em Gaúcha do Norte-MT (13° 10'S e 53° 15' O), na borda sul-amazônica. Para o levantamento fitossociológico, três áreas amostrais de 1ha foram subdivididas em 50 parcelas de 10x20m, nas quais foram amostrados todos os indivíduos com perímetro à altura do peito (PAP) $15 cm. Para verificar a similaridade estrutural entre as áreas utilizou-se a Análise de Correspondência. As espécies indicadoras dos ambientes de interflúvio e das áreas sujeitas à inundação foram obtidas através do TWINSPAN e de um sistema de pesos. Concluiu-se que as florestas presentes na bacia do rio Pacuneiro pertencem à mesma unidade fitogeográfica, mas com subtipos florísticos e estruturais de acordo com a posição no relevo, a proximidade dos cursos d'água e o estrato analisado, apresentando predominância de algumas espécies, ou até mesmo possíveis endemismos, em determinados trechos ou estratos. A formação apresentou baixa diversidade alfa (2,91 a 3,50) e beta (3,62 a 3,86), o que não é comum em florestas amazônicas. Várias hipóteses podem explicar essa baixa diversidade, entre elas a baixa precipitação e a alta sazonalidade, o ambiente físico regional aparentemente homogêneo e favorável às espécies competidoras, ou os eventos históricos, relacionados à possível exploração por tribos indígenas ou à recente expansão dessas florestas sobre as áreas savânicas. PALAVRAS-CHAVEAmazônia, Xingu, floresta Amazônica, estrutura florestal. Structure of patch of Amazonian forest in the alto

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High tree alpha-diversity in Amazonian Ecuador

Cited by 331 publications

References 12 publications

Macrofungal diversity in Colombian Amazon forests varies with regions and regimes of disturbance

Macrofungal diversity in Colombian Amazon forests varies with regions and regimes of disturbance

Parasites dominate hyperdiverse soil protist communities in Neotropical rainforests

Estrutura de um trecho de floresta Amazônica na bacia do alto rio Xingu

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