Landscape patterns influence communities of medium- to large-bodied vertebrates in undisturbed terra firme forests of French Guiana

2015 ◽  
Vol 31 (5) ◽  
pp. 423-436 ◽  
Author(s):  
Cécile Richard-Hansen ◽  
Gaëlle Jaouen ◽  
Thomas Denis ◽  
Olivier Brunaux ◽  
Eric Marcon ◽  
...  

Abstract:Whereas broad-scale Amazonian forest types have been shown to influence the structure of the communities of medium- to large-bodied vertebrates, their natural heterogeneity at smaller scale or within the terra firme forests remains poorly described and understood. Diversity indices of such communities and the relative abundance of the 21 most commonly observed species were compared from standardized line-transect data across 25 study sites distributed in undisturbed forests in French Guiana. We first assessed the relevance of a forest typology based on geomorphological landscapes to explain the observed heterogeneity. As previously found for tree beta-diversity patterns, this new typology proved to be a non-negligible factor underlying the beta diversity of the communities of medium- to large bodied vertebrates in French Guianan terra firme forests. Although the species studied are almost ubiquitous across the region, they exhibited habitat preferences through significant variation in abundance and in their association index with the different landscape types. As terra firme forests represent more than 90% of the Amazon basin, characterizing their heterogeneity – including faunal communities – is a major challenge in neotropical forest ecology.

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 745
Author(s):  
Michelle Martin de Bustamante ◽  
Diego Gomez ◽  
Jennifer MacNicol ◽  
Ralph Hamor ◽  
Caryn Plummer

The objective of this study was to describe and compare the fecal bacterial microbiota of horses with equine recurrent uveitis (ERU) and healthy horses using next-generation sequencing techniques. Fecal samples were collected from 15 client-owned horses previously diagnosed with ERU on complete ophthalmic examination. For each fecal sample obtained from a horse with ERU, a sample was collected from an environmentally matched healthy control with no evidence of ocular disease. The Illumina MiSeq sequencer was used for high-throughput sequencing of the V4 region of the 16S rRNA gene. The relative abundance of predominant taxa, and alpha and beta diversity indices were calculated and compared between groups. The phyla Firmicutes, Bacteroidetes, Verrucomicrobia, and Proteobacteria predominated in both ERU and control horses, accounting for greater than 60% of sequences. Based on linear discriminant analysis effect size (LEfSe), no taxa were found to be enriched in either group. No significant differences were observed in alpha and beta diversity indices between groups (p > 0.05 for all tests). Equine recurrent uveitis is not associated with alteration of the gastrointestinal bacterial microbiota when compared with healthy controls.


2021 ◽  
Vol 48 (2) ◽  
pp. 441-456
Author(s):  
Ashikur Rahman Shome ◽  
Md Mahabub Alam ◽  
Md Fazle Rabbe ◽  
Mohammad Mijanur Rahman ◽  
Mohammad Firoj Jaman

A study on diversity, status, and habitat preference of avifauna was conducted from November 2017 to October 2018 in Magura Sadar upazila, Magura. Data was collected through direct field observations using line-transect method. Field surveys were made for three days per month in both rural and urban sites. A total of 140 species of birds belonged to 18 orders and 48 families were reported. Among the total species, 55% (77 species) were non-passerines and 45% (63 species) passerines with the highest individuals were counted under order Passeriformes. Resident bird species were dominant (106 species, 75.71%) over migratory (34 species, 24.28%) species. Species richness was the highest in the rural areas (124 species, 88.57%) and occurrence was the highest in winter season (97 species, 69.29%). The maximum species were recorded from trees (87 species, 62.14%) as preferred habitat. In this study, in total 4,060 individuals of birds were counted and among them, 51.55% (n=2093) were observed in the rural areas and 48.45% (n=1967) were in the urban areas. The highest number of birds was found in December (10.34%, n=432) and seasonal abundance was the highest in winter (40.15%, n=1630). Abundance was the highest for Common Myna (5.76%, n=234) among all recorded species. Diversity indices showed that the bird species were the most diverse in the rural areas in the winter season and in July. Habitat diversity indices were the highest for trees and birds used different types of habitats at different times for roosting, breeding and feeding. Regarding the observation status, 29.28% species was very common, 4.28% common, 31.42% fairly common, and 35% were few. This baseline data indicate that this study site is significant from the ecological and conservation point of views. Therefore, further research is necessary to understand how this avian diversity is maintained in this ecological setting. Bangladesh J. Zool. 48(2): 441-456, 2020


2018 ◽  
Vol 15 (1) ◽  
pp. 279-295 ◽  
Author(s):  
Corina Buendía ◽  
Axel Kleidon ◽  
Stefano Manzoni ◽  
Björn Reu ◽  
Amilcare Porporato

Abstract. Phosphorus (P) availability decreases with soil age and potentially limits the productivity of ecosystems growing on old and weathered soils. Despite growing on ancient soils, ecosystems of lowland Amazonia are highly productive and are among the most biodiverse on Earth. P eroded and weathered in the Andes is transported by the rivers and deposited in floodplains of the lowland Amazon basin creating hotspots of P fertility. We hypothesize that animals feeding on vegetation and detritus in these hotspots may redistribute P to P-depleted areas, thus contributing to dissipate the P gradient across the landscape. Using a mathematical model, we show that animal-driven spatial redistribution of P from rivers to land and from seasonally flooded to terra firme (upland) ecosystems may sustain the P cycle of Amazonian lowlands. Our results show how P imported to land by terrestrial piscivores in combination with spatial redistribution of herbivores and detritivores can significantly enhance the P content in terra firme ecosystems, thereby highlighting the importance of food webs for the biogeochemical cycling of Amazonia.


Nativa ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 323-328
Author(s):  
Gabriel Araújo Paes Freire ◽  
Dione Judite Ventura ◽  
Igor Georgios Fotopoulos ◽  
Diogo Martins Rosa ◽  
Renata Gonçalves Aguiar ◽  
...  

O objetivo deste estudo foi avaliar a produção e decomposição de serapilheira em uma área de floresta primária de terra firme na Reserva Biológica do Jaru. Para tanto, foi implantada uma parcela permanente de 1 hectare, onde foram demarcadas 25 subparcelas com 20 x 20 m cada. Para a coleta de serapilheira, instalou-se 25 coletores de PVC (1 em cada centro da subparcela), medindo 0,25 m², a 1 metro do solo, com malha de nylon de 1 mm. Para estimar o estoque de serapilheira, utilizou-se 25 coletores de madeira, medindo 0,25 m², com malha de nylon de 1 mm, dispostos no solo de cada subparcela. As coletas da pesquisa foram realizadas quinzenalmente, entre os meses de outubro de 2016 a setembro de 2017, e a serapilheira triada nas frações: folha, galho, material reprodutivo e miscelânea. No laboratório, os materiais amostrados foram secos em estufa à 80 ºC e pesados em balança de precisão centesimal, sendo que a decomposição de serapilheira foi estimada através da relação entre produção e estoque. De acordo com os resultados obtidos, a produção de serapilheira total foi de 14,13 Mg ha-1 e as frações seguiram o padrão: folhamiscelâneagalhomaterial reprodutivo. As maiores produções aconteceram na estação seca e a taxa de decomposição foi 1,37, indicando que a atividade microbiana na área de estudo é acelerada.Palavras-chave: dinâmica sazonal; nutrição de plantas; ecologia florestal; decomposição. LITTER DYNAMICS IN A FOREST AREA OF GROUND FIRM, WESTERN AMAZON ABSTRACT:The objective of this study was to evaluate the litter production and decomposition in an area of primary upland forest in the Jaru Biological Reserve. For that, a permanent plot of 1 hectare was implanted, where 25 subplots with 20 x 20 m each were demarcated. For the collection of litter, 25 PVC collectors were installed (1 in each center of the subplot), measuring 0.25 m², 1 meter from the ground, with 1 mm nylon mesh. To estimate the litter stock, 25 wood collectors, measuring 0.25 m², with 1 mm nylon mesh, were used, arranged in the soil of each subplot. The collections of the research were carried out fortnightly, between the months of October 2016 and September 2017, and the litter is sorted in the fractions: leaf, branch, reproductive material and miscellaneous. In the laboratory, the sampled materials were dried in an oven at 80 ºC and weighed on a centesimal precision scale, and the litter decomposition was estimated through the relationship between production and stock. According to the results obtained, the total litter production was 14.13 Mg ha-1 and the fractions followed the pattern: leafmiscellaneousbranchreproductive material. The highest yields occurred in the dry season and the decomposition rate was 1.37, indicating that the microbial activity in the study area is accelerated.Keyword: seasonal dynamics; plant nutrition; forest ecology; decomposition.


2021 ◽  
Vol 9 (11) ◽  
pp. 2339
Author(s):  
Aleksei O. Zverev ◽  
Arina A. Kichko ◽  
Aleksandr G. Pinaev ◽  
Nikolay A. Provorov ◽  
Evgeny E. Andronov

The rhizosphere community represents an “ecological interface” between plant and soil, providing the plant with a number of advantages. Despite close connection and mutual influence in this system, the knowledge about the connection of plant and rhizosphere diversity is still controversial. One of the most valuable factors of this uncertainty is a rough estimation of plant diversity. NGS sequencing can make the estimations of the plant community more precise than classical geobotanical methods. We investigate fallow and crop sites, which are similar in terms of environmental conditions and soil legacy, yet at the same time are significantly different in terms of plant diversity. We explored amplicons of both the plant root mass (ITS1 DNA) and the microbial communities (16S rDNA); determined alpha- and beta-diversity indices and their correlation, and performed differential abundance analysis. In the analysis, there is no correlation between the alpha-diversity indices of plants and the rhizosphere microbial communities. The beta-diversity between rhizosphere microbial communities and plant communities is highly correlated (R = 0.866, p = 0.01). ITS1 sequencing is effective for the description of plant root communities. There is a connection between rhizosphere communities and the composition of plants, but on the alpha-diversity level we found no correlation. In the future, the connection of alpha-diversities should be explored using ITS1 sequencing, even in more similar plant communities—for example, in different synusia.


Zoodiversity ◽  
2021 ◽  
Vol 55 (6) ◽  
pp. 451-458
Author(s):  
G. Kopij

The line transect method has been employed to assess species diversity, population densities and community structure of birds breeding in a mosaic of Kalahari Woodland and farmland, NE Namibia. The transect, 4.5 km long, was surveyed in 2014 and 2015. The total annual rainfall in 2014 was much higher than in 2015 (427 mm vs. 262 mm). In total, 40 breeding species in 2014, and 46 in 2015 were recorded. Six species were dominant in 2014 (Cape Turtle Dove, Laughing Dove, Emerald-spotted Dove, Blue Waxbill, and White-browed Scrub Robin) and only three species in 2015 (Cape Turtle Dove and Blue Waxbill and Yellow-fronted Canary). Although the cumulative dominance in 2014 almost doubled that in 2015, the Community Index in both years was almost identical. Also diversity indices and evenness index were very similar in both years compared. Granivorous birds were the most numerous feeding guild. Their contribution was similar in 2014 and 2015 (46.7 % vs. 43.4 %). Two other feeding guilds, insectivores and frugivores, comprised together more than 50 % in both years. The number of bird species and species diversity were not influenced by the differential rainfall. However, contrary to expectations, population densities of most bird species (at least the more numerous ones) were higher in the year with lower than in the year with higher rainfall. The number of species and species diversity was similar in the farmland and in neighbouring Kalahari Woodland in a pristine stage. However, population densities of most species were lower in the farmland than in the pristine woodland.


2021 ◽  
Author(s):  
Diego Rodrigues Guilherme ◽  
Pedro Aurélio Costa Lima Pequeno ◽  
Fabrício Beggiato Baccaro ◽  
Elizabeth Franklin ◽  
Cláudio Rabelo dos Santos Neto ◽  
...  

Abstract To understand better the effects of niche and neutral processes is important to disentangle the direct and indirect effects of each process, mainly if the environmental factors are geographically structured neglecting important indirect and synergic effects. We sampled ground-dwelling ant species on 126 plots distributed across eight sampling sites along a broad environmental gradient in Central Amazonia. Structural equation modelling was employed to quantify direct and indirect effects of geographic distance, the Amazon River’s opposite margins, and environmental differences in temperature, precipitation and vegetation structure (Normalized Difference Vegetation Index) on ant beta diversity (Jaccard’s dissimilarity). We found that geographic distance and NDVI differences had major direct effects on ant beta diversity. The major effect of temperature was indirect through NDVI, whereas precipitation had no detectable effect on beta diversity. The Amazon River had a weak influence on the ant composition dissimilarity. Our results challenge the major role often ascribed to riverine barriers in the diversification and distribution of Amazonian biota. Rather, ant compositional dissimilarity seems to be mainly driven by a combination of dispersal limitation and selection imposed by vegetation features and, indirectly, by temperature. We suggest that as NDVI differences decrease with geographic distance in the region, isolation by distance may have favoured phenotypic convergence between ant communities in the northern and southern borders of the Amazon Basin.


Phytotaxa ◽  
2016 ◽  
Vol 261 (1) ◽  
pp. 75
Author(s):  
RODRIGO A. CAMARGO ◽  
ANA MARIA G.A. TOZZI

A new combination is proposed for Millettia occidentalis, a rare liana endemic to a small locality of the Amazon Basin, in Brazil. Morphology and geographic distribution supports its transfer to Deguelia and a specimen at IAN is designated as lectotype. Validation in Deguelia is needed for use in impending floristic treatments, as well as to promote conservation and new field efforts. It occurs in “terra firme” forests (non-flooded), on high lands and appears to be very rare range-wide, based on documented occurrences. Description, illustration, distribution map, some ecological notes and a preliminary evaluation of its conservation assessment are provided.


Diversity ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 101 ◽  
Author(s):  
Sándor Bartha ◽  
Roberto Canullo ◽  
Stefano Chelli ◽  
Giandiego Campetella

Patterns of diversity across spatial scales in forest successions are being overlooked, despite their importance for developing sustainable management practices. Here, we tested the recently proposed U-shaped biodiversity model of forest succession. A chronosequence of 11 stands spanning from 5 to 400 years since the last disturbance was used. Understory species presence was recorded along 200 m long transects of 20 × 20 cm quadrates. Alpha diversity (species richness, Shannon and Simpson diversity indices) and three types of beta diversity indices were assessed at multiple scales. Beta diversity was expressed by a) spatial compositional variability (number and diversity of species combinations), b) pairwise spatial turnover (between plots Sorensen, Jaccard, and Bray–Curtis dissimilarity), and c) spatial variability coefficients (CV% of alpha diversity measures). Our results supported the U-shaped model for both alpha and beta diversity. The strongest differences appeared between active and abandoned coppices. The maximum beta diversity emerged at characteristic scales of 2 m in young coppices and 10 m in later successional stages. We conclude that traditional coppice management maintains high structural diversity and heterogeneity in the understory. The similarly high beta diversities in active coppices and old-growth forests suggest the presence of microhabitats for specialist species of high conservation value.


Zootaxa ◽  
2012 ◽  
Vol 3249 (1) ◽  
pp. 18 ◽  
Author(s):  
ANA P. MOTTA ◽  
SANTIAGO CASTROVIEJO-FISHER ◽  
PABLO J. VENEGAS ◽  
VICTOR G.D. ORRICO ◽  
JOSÉ M. PADIAL

We describe Dendropsophus frosti sp. nov. from lowland terra firme rainforests of the headwaters of the Amazon RiverBasin in Colombia and Peru. The new species is known from only two localities, the type locality near Leticia (Departa-mento Amazonas, Colombia, 04° 06' 24.2" S, 69° 56' 57.4" W; 103 m.a.s.l.), and the paratopotypic locality, Piedras in thePutumayo basin (Departamento Loreto, Peru, 02.79278° S, 72.91750° W; 90–170 m.a.s.l.). Maximum likelihood and par-simony analyses of 2436 aligned base pairs of the 12S and 16S rRNA genes recovered the new species as a member of D.parviceps group and sister to D. brevifrons. The new species is most closely related to D. parviceps, D. brevifrons, and D.koechlini, and it can be readily distinguished from these and all other members of the D. parviceps group by, among othercharacters, its plain dorsal light brown coloration, copper iris, plain immaculate pale yellow to white venter coloration, lack of flash marks on groin and axillae, and absence of white spots on lips.


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