Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.559
Filtrar
1.
J Exp Bot ; 75(13): 3758-3761, 2024 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-38982745

RESUMEN

This insight article comments on: Ziegler C, Cochard, H, Stahl C, Bastien Gérard LF, Goret J, Heuret P, Levionnois S, Maillard P, Bonal D, Coste S. 2024. Residual water losses mediate the trade-off between growth and drought survival across saplings of 12 tropical rainforest tree species with contrasting hydraulic strategies. Journal of Experimental Botany 75, 4128-4147.


Asunto(s)
Sequías , Árboles , Árboles/fisiología , Árboles/crecimiento & desarrollo , Bosque Lluvioso , Agua/metabolismo , Agua/fisiología , Estrés Fisiológico
2.
Am Nat ; 204(2): 105-120, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39008837

RESUMEN

AbstractInteractions between and within abiotic and biotic processes generate nonadditive density-dependent effects on species performance that can vary in strength or direction across environments. If ignored, nonadditivities can lead to inaccurate predictions of species responses to environmental and compositional changes. While there are increasing empirical efforts to test the constancy of pairwise biotic interactions along environmental and compositional gradients, few assess both simultaneously. Using a nationwide forest inventory that spans broad ambient temperature and moisture gradients throughout New Zealand, we address this gap by analyzing the diameter growth of six focal tree species as a function of neighbor densities and climate, as well as neighbor × climate and neighbor × neighbor statistical interactions. The most complex model featuring all interaction terms had the highest predictive accuracy. Compared with climate variables, biotic interactions typically had stronger effects on diameter growth, especially when subjected to nonadditivities from local climatic conditions and the density of intermediary species. Furthermore, statistically strong (or weak) nonadditivities could be biologically irrelevant (or significant) depending on whether a species pair typically interacted under average or more extreme conditions. Our study highlights the importance of considering both the statistical potential and the biological relevance of nonadditive biotic interactions when assessing species performance under global change.


Asunto(s)
Bosque Lluvioso , Árboles , Árboles/crecimiento & desarrollo , Nueva Zelanda , Modelos Biológicos , Clima , Cambio Climático
3.
Ying Yong Sheng Tai Xue Bao ; 35(5): 1242-1250, 2024 May.
Artículo en Chino | MEDLINE | ID: mdl-38886422

RESUMEN

In this study, we used a high-throughput sequencing technology to survey the dry-wet seasonal change characteristics of soil ammonia-oxidizing bacteria (AOB) communities in the three restoration stages [i.e., Mallotus paniculatus community (early stage), Millettia leptobotrya community (middle stage), and Syzygium oblatum community (later stage)] of Xishuangbanna tropical forest ecosystems. We analyzed the effects of soil physicochemical characteristics on AOB community composition and diversity during tropical forest restoration. The results showed that tropical forest restoration significantly affected the relative abundance of dominant AOB phyla and their dry-wet seasonal variation. The maximum relative abundance of Proteobacteria (71.3%) was found in the early recovery stage, while that of Actinobacteria was found in the late recovery stage (1.0%). The abundances of Proteobacteria and Actinobacteria had the maximum ranges of dry-wet seasonal variation in the early and late stages, respectively. The abundance of dominant AOB genera and its dry-wet seasonal variation varied across tropical forest restoration stages. The maximum average relative abundance of Nitrosospira and Nitrosomonas in the late recovery stage was 66.2% and 1.5%, respectively. In contrast, the abundance of Nitrosovibrio reached its maximum (25.6%) in the early recovery stage. The maximum dry-wet seasonal variation in relative abundance of Nitrosospira and Nitrosomonas occurred in the early recovery stage, while that of Nitrosovibrio occurred in the middle recovery stage. The Chao1, Shannon, and Simpson diversity indices of AOB communities increased along the restoration stages, which were significantly higher in the wet season than in the dry season. The results of canonical correspondence analysis showed that soil easily oxidized carbon was the main factor controlling AOB community diversity and Actinobacteria abundance. Soil bulk density and temperature were the main factors affecting Proteobacteria abundance. Soil pH, microbial biomass carbon, water content, ammonium nitrogen, bulk density, and temperature were the main factors controlling the abundances of Nitrosospira, Nitrosomonas, and Nitrosovibrio. Therefore, tropical forest restoration can regulate the change of relative abundance of dominant AOB taxa via mediating the changes of soil temperature, bulk density, and readily oxidized carbon, leading to an increase in soil AOB community diversity.


Asunto(s)
Amoníaco , Bacterias , Bosques , Oxidación-Reducción , Estaciones del Año , Microbiología del Suelo , Clima Tropical , Amoníaco/metabolismo , Bacterias/clasificación , Bacterias/metabolismo , Bacterias/aislamiento & purificación , Bacterias/genética , Bacterias/crecimiento & desarrollo , Proteobacteria/aislamiento & purificación , Proteobacteria/clasificación , Proteobacteria/metabolismo , Proteobacteria/genética , China , Conservación de los Recursos Naturales , Restauración y Remediación Ambiental/métodos , Nitrosomonas/metabolismo , Nitrosomonas/clasificación , Nitrosomonas/crecimiento & desarrollo , Bosque Lluvioso
5.
Sci Rep ; 14(1): 14007, 2024 06 18.
Artículo en Inglés | MEDLINE | ID: mdl-38890332

RESUMEN

Species conservation assessments using the criteria outlined by the International Union for the Conservation of Nature Red List can be compromised by limited data availability. Species-rich tropical plant taxa with numerous microendemics are particularly problematic. This study focusses on the Begonia flora of the Indonesian island of Sulawesi, comprised of 65 herbaceous species mainly found in rainforest habitats. Sixty-two species are Sulawesi endemics, including 20 species restricted to limestone karst landscapes. Forty-eight species are represented by fewer than 10 herbarium collections. Here, we outline and discuss an approach that, despite these data limitations, allows meaningful conservation assessments by integrating analyses of occurrences, data primarily based on remote sensing approaches, including forest landscape integrity, forest cover loss, and land cover, and extent of suitable habitat estimation. The results indicate that most Sulawesi Begonia species are narrow endemics whose rainforest habitats have substantially deteriorated in the last two decades: 27 species are assessed as Critically Endangered, 24 as Endangered, six as Vulnerable, five as Least Concern, and three species are Data Deficient. Conservation action, including extension of the protected area network in Sulawesi with emphasis on areas of old-growth forest and limestone karst landscapes, and strengthening of ex-situ living collections, is recommended.


Asunto(s)
Begoniaceae , Conservación de los Recursos Naturales , Especies en Peligro de Extinción , Conservación de los Recursos Naturales/métodos , Indonesia , Begoniaceae/fisiología , Ecosistema , Bosque Lluvioso , Biodiversidad , Clima Tropical
6.
Sci Total Environ ; 944: 173918, 2024 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-38866151

RESUMEN

Per- and polyfluoroalkyl substances (PFAS), often referred to as "forever chemicals", are a class of man-made, extremely stable chemicals, which are widely used in industrial and commercial applications. Exposure to some PFAS is now known to be detrimental to human health. By virtue of PFAS long residence times, they are widely detected in the environment, including remote locations such as the Arctics, where the origin of the PFAS is poorly understood. It has been suggested that PFAS may be transported through contaminated waters, leading to accumulation in coastal areas, where they can be aerosolised via sea spray, thereby extending their geographical distribution far beyond their original source regions. The aim of this work is to investigate, for the first time, whether "forever chemicals" could be transported to areas considered to be pristine, far from coastal sites. This study was performed at the Amazonian Tall Tower Observatory (ATTO), a unique remote site situated in the middle of the Amazon rainforest, where a restricted PFAS, perfluorooctanoic acid (PFOA), was observed with concentrations reaching up to 2 pg/m3. A clear trend of increasing concentration with sampling height was observed and air masses from the south over Manaus had the highest concentrations. Atmospheric lifetime estimations, removal mechanisms supported by measurements at two heights (320 and 42 m above the rainforest), and concentration spikes indicated a long-range transport of PFOA to pristine Amazon rainforest. Potential sources, including industrial activities in urban areas, were explored, and historical fire management practices considered. This research presents the first measurements of PFAS in the atmosphere of Amazon rainforest. Remarkably, even in this remote natural environment, appreciable levels of PFAS can be detected. This study provides valuable insights into the long-range transport of the anthropogenic "forever chemical" into a remote natural ecosystem and should raise awareness of potential environmental implications.


Asunto(s)
Contaminantes Atmosféricos , Atmósfera , Monitoreo del Ambiente , Fluorocarburos , Contaminantes Atmosféricos/análisis , Fluorocarburos/análisis , Atmósfera/química , Brasil , Caprilatos/análisis , Bosque Lluvioso
7.
Mol Phylogenet Evol ; 198: 108117, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38852908

RESUMEN

The Least Nighthawk Chordeiles pusillus is widespread wherever there are savannas in the South American tropics, often in isolated patches, such as white-sands savannas in the Amazon rainforest realm. Here, we investigate genetic relationships between populations of the Least Nighthawk to understand historical processes leading to its diversification and to determine dispersal routes between northern and southern savannas by way of three hypothesized dispersal corridors by comparing samples from white-sand savannas to samples from other savannas outside of the Amazon rainforest region. We use 32 mtDNA samples from the range of C. pusillus to infer a dated phylogeny. In a subset of 17 samples, we use shotgun sequences to infer a distance-based phylogeny and to estimate individual admixture proportions. We calculate gene flow and shared alleles between white-sand and non-Amazonian populations using the ABBA-BABA test (D statistics), and Principal Component Analysis (PCA) to examine genetic structure within and between lineages. Finally, we use species distribution modelling (SDM) of conditions during the Last Glacial Maximum (LGM), currently, and in the future (2050-2080) to predict potential species occurrence under a climate change scenario. Two main clades (estimated to have diverged around 1.07 million years ago) were recovered with mtDNA sequences and Single Nucleotide Polymorphism (SNPs) and were supported by NGSadmix and PCA: one in the Amazon basin white-sand savannas, the other in the non-Amazonian savannas. Possible allele sharing between these clades was indicated by the D-statistics between northern non-Amazonian populations and the white-sand savanna population, but this was not corroborated by the admixture analyses. Dispersal among northern non-Amazonian populations may have occurred in a dry corridor between the Guianan and the Brazilian Shield, which has since moved eastward. Our data suggest that the lineages separated well before the Last Glacial Maximum, consequently dispersal could have happened at any earlier time during similar climatic conditions. Subsequently, non-Amazonian lineages became more divergent among themselves, possibly connecting and dispersing across the mouth of the Amazon River across Marajó island during favourable climatic conditions in the Pleistocene.


Asunto(s)
ADN Mitocondrial , Especiación Genética , Filogenia , Animales , América del Sur , ADN Mitocondrial/genética , Pradera , Flujo Génico , Bosque Lluvioso , Genética de Población
8.
Yeast ; 41(7): 437-447, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38850070

RESUMEN

Four yeast isolates were obtained from rotting wood and galleries of passalid beetles collected in different sites of the Brazilian Amazonian Rainforest in Brazil. This yeast produces unconjugated allantoid asci each with a single elongated ascospore with curved ends. Sequence analysis of the internal transcribed spacer-5.8 S region and the D1/D2 domains of the large subunit ribosomal RNA (rRNA) gene showed that the isolates represent a novel species of the genus Spathaspora. The novel species is phylogenetically related to a subclade containing Spathaspora arborariae and Spathaspora suhii. Phylogenomic analysis based on 1884 single-copy orthologs for a set of Spathaspora species whose whole genome sequences are available confirmed that the novel species represented by strain UFMG-CM-Y285 is phylogenetically close to Sp. arborariae. The name Spathaspora marinasilvae sp. nov. is proposed to accommodate the novel species. The holotype of Sp. marinasilvae is CBS 13467 T (MycoBank 852799). The novel species was able to accumulate xylitol and produce ethanol from d-xylose, a trait of biotechnological interest common to several species of the genus Spathaspora.


Asunto(s)
Escarabajos , Filogenia , Bosque Lluvioso , Saccharomycetales , Madera , Xilosa , Animales , Madera/microbiología , Escarabajos/microbiología , Brasil , Saccharomycetales/genética , Saccharomycetales/clasificación , Saccharomycetales/aislamiento & purificación , Saccharomycetales/metabolismo , Xilosa/metabolismo , Fermentación , ADN de Hongos/genética , Análisis de Secuencia de ADN
9.
An Acad Bras Cienc ; 96(3): e20230629, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38922254

RESUMEN

The current study proposes to investigate the diversity and phylogeny of trypanosomes parasitizing wild birds from the Brazilian Atlantic Forest. Cytological examination was carried out by light microscopy of blood smears and positive birds were selected for amplification of the 18S rDNA sequence through PCR. The resulting amplicons were subjected to purification, cloning, and sequencing analysis. Phylogenetic reconstruction was conducted, including all avian trypanosomes representative's lineages. A total of ten bird samples from species of Turdus flavipes (N=1/12), T. albicollis (N=1/8), Tachyphonus coronatus (N=6/121), Thamnophilus caerulescens (N=1/22) and Synallaxis spixi (N=1/8) were positive for Trypanosoma spp. In the six specimens of T. coronatus, five distinct lineages of Trypanosoma spp. 18S-rRNA were observed in ninety sequences obtained, and using the strategy of cloning independent PCR, it was possible to observe that two of them were related to T. avium (JB01/JB02), and three were closed related to T. bennetti (JB03/ JB04/JB05). Addionaly, all fifteen sequences obtained from T. caerulescens/ S. spixi/T. flavipes/T. albicollis were identical. The present research is the first study to access molecular diversity and polyparasitism by avian trypanosomes in Brazil. The current research exhibits the wide genetic variability in avian trypanosomes and its non-specific relationship with its avian hosts.


Asunto(s)
Aves , Filogenia , Reacción en Cadena de la Polimerasa , Trypanosoma , Animales , Brasil , Trypanosoma/clasificación , Trypanosoma/genética , Trypanosoma/aislamiento & purificación , Aves/parasitología , Bosque Lluvioso , ARN Ribosómico 18S/genética , ADN Protozoario/genética , Tripanosomiasis/veterinaria , Tripanosomiasis/parasitología , Enfermedades de las Aves/parasitología , Variación Genética , ADN Ribosómico/genética , Análisis de Secuencia de ADN
11.
Chemosphere ; 361: 142425, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38797216

RESUMEN

Artisanal and small-scale gold mining (ASGM) is the primary global source of anthropogenic mercury (Hg) emissions. It has impacted the Amazon rainforest in the Peruvian region of Madre de Dios. However, few studies have investigated Hg's distribution in terrestrial ecosystems in this region. We studied Hg's distribution and its predictors in soil and native plant species from artisanal mining sites. Total Hg concentrations were determined in soil samples collected at different depths (0-5 cm and 5-30 cm) and plant samples (roots, shoots, leaves) from 19 native plant species collected in different land cover categories: naked soil (L1), gravel piles (L2), natural regeneration (L3), reforestation (L4), and primary forest (L5) in the mining sites. Hg levels in air were also studied using passive air samplers. The highest Hg concentrations in soil (average 0.276 and 0.210 mg kg-1 dw.) were found in the intact primary forest (L5) at 0-5 cm depth and in the plant rooting zones at 5-30 cm depth, respectively. Moreover, the highest Hg levels in plants (average 0.64 mg kg-1 dw) were found in foliage of intact primary forest (L5). The results suggest that the forest in these sites receives Hg from the atmosphere through leaf deposition and that Hg accumulates in the soil surrounding the roots. The Hg levels found in the plant leaves of the primary forest are the highest ever recorded in this region, exceeding values found in forests impacted by Hg pollution worldwide and raising concerns about the extent of the ASGM impact in this ecosystem. Correlations between Hg concentrations in soil, bioaccumulation in plant roots, and soil physical-chemical characteristics were determined. Linear regression models showed that the soil organic matter content (SOM), pH, and electrical conductivity (EC) predict the Hg distribution and accumulation in soil and bioaccumulation in root plants.


Asunto(s)
Monitoreo del Ambiente , Oro , Mercurio , Minería , Contaminantes del Suelo , Suelo , Mercurio/análisis , Perú , Contaminantes del Suelo/análisis , Suelo/química , Plantas/metabolismo , Ecosistema , Bosques , Bosque Lluvioso
12.
Ann Bot ; 134(2): 337-350, 2024 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-38721801

RESUMEN

BACKGROUND AND AIMS: Lianas have higher relative abundance and biomass in drier seasonal forests than in rainforests, but whether this difference is associated with their hydraulic strategies is unclear. Here, we investigate whether lianas of seasonally dry forests are safer and more efficient in water transport than rainforest lianas, explaining patterns of liana abundance. METHODS: We measured hydraulic traits on five pairs of congeneric lianas of the tribe Bignonieae in two contrasting forest sites: the wet 'Dense Ombrophilous Forest' in Central Amazonia (~2 dry months) and the drier 'Semideciduous Seasonal Forest' in the inland Atlantic Forest (~6 dry months). We also gathered a broader database, including 197 trees and 58 liana species from different tropical forests, to compare hydraulic safety between habits and forest types. KEY RESULTS: Bignonieae lianas from both forests had high and similar hydraulic efficiency but exhibited variability in resistance to embolism across forest types when phylogenetic relationships were taken into account. Three genera had higher hydraulic safety in the seasonal forest than in the rainforest, but species across both forests had similar positive hydraulic safety margins despite lower predawn water potential values of seasonal forest lianas. We did not find the safety-efficiency trade-off. Merging our results with previously published data revealed a high variability of resistance to embolism in both trees and lianas, independent of forest types. CONCLUSIONS: The high hydraulic efficiency of lianas detected here probably favours their rapid growth across tropical forests, but differences in hydraulic safety highlight that some species are highly vulnerable and may rely on other mechanisms to cope with drought. Future research on the lethal dehydration threshold and the connection between hydraulic resistance strategies and liana abundance could offer further insights into tropical forest dynamics under climatic threats.


Asunto(s)
Bosque Lluvioso , Estaciones del Año , Clima Tropical , Bosques , Agua/fisiología , Bignoniaceae/fisiología , Árboles/fisiología , Brasil
13.
New Phytol ; 243(2): 648-661, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38757766

RESUMEN

Elevated air temperature (Tair) and vapour pressure deficit (VPDair) significantly influence plant functioning, yet their relative impacts are difficult to disentangle. We examined the effects of elevated Tair (+6°C) and VPDair (+0.7 kPa) on the growth and physiology of six tropical tree species. Saplings were grown under well-watered conditions in climate-controlled glasshouses for 6 months under three treatments: (1) low Tair and low VPDair, (2) high Tair and low VPDair, and (3) high Tair and high VPDair. To assess acclimation, physiological parameters were measured at a set temperature. Warm-grown plants grown under elevated VPDair had significantly reduced stomatal conductance and increased instantaneous water use efficiency compared to plants grown under low VPDair. Photosynthetic biochemistry and thermal tolerance (Tcrit) were unaffected by VPDair, but elevated Tair caused Jmax25 to decrease and Tcrit to increase. Sapling biomass accumulation for all species responded positively to an increase in Tair, but elevated VPDair limited growth. This study shows that stomatal limitation caused by even moderate increases in VPDair can decrease productivity and growth rates in tropical species independently from Tair and has important implications for modelling the impacts of climate change on tropical forests.


Asunto(s)
Hojas de la Planta , Estomas de Plantas , Bosque Lluvioso , Temperatura , Árboles , Presión de Vapor , Árboles/fisiología , Árboles/crecimiento & desarrollo , Hojas de la Planta/fisiología , Hojas de la Planta/crecimiento & desarrollo , Estomas de Plantas/fisiología , Clima Tropical , Fotosíntesis , Especificidad de la Especie , Agua/metabolismo , Transpiración de Plantas/fisiología , Biomasa , Gases/metabolismo
14.
Phys Rev E ; 109(4): L042402, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38755841

RESUMEN

Tropical rainforests exhibit a rich repertoire of spatial patterns emerging from the intricate relationship between the microscopic interaction between species. In particular, the distribution of vegetation clusters can shed much light on the underlying process that regulates the ecosystem. Analyzing the distribution of vegetation clusters at different resolution scales, we show the first robust evidence of scale-invariant clusters of vegetation, suggesting the coexistence of multiple intertwined scales in the collective dynamics of tropical rainforests. We use field data and computational simulations to confirm our hypothesis, proposing a predictor that could be particularly interesting to monitor the ecological resilience of the world's "green lungs."


Asunto(s)
Bosque Lluvioso , Clima Tropical , Modelos Biológicos , Plantas , Simulación por Computador
15.
PeerJ ; 12: e17383, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38770092

RESUMEN

Background: We studied the occurrence of two sympatric wallabies, the red-necked pademelon (Thylogale thetis) and the red-legged pademelon (T. stigmatica) in northeastern New South Wales, Australia in relation to structural habitat attributes. At our study site, both species inhabit closed forest environments and have overlapping distributions, but T. thetis leaves the forest at night to graze adjacent grassy forest edges whereas T. stigmatica remains within the forest and browses forest vegetation. The objectives of the study were to investigate how structural attributes of two forest types, wet sclerophyll forest and rainforest, relate to the fine-scale occurrence of these two wallaby species within the forested environment. Methods: We gathered occurrence data from 48 camera trap stations divided equally between rainforest and wet sclerophyll forest. At each camera point, we also measured a range of structural habitat attributes to determine habitat affiliations for the two Thylogale species. Principal component analyses were used to describe major trends in habitat, and generalised linear models were used to describe the efficacy of the variables in predicting habitat occurrence of each species. Results: The number of occurrences of Thylogale thetis was significantly greater than occurrences of T. stigmatica, which was driven by significantly greater occurrences of T. thetis in wet sclerophyll forest. There was both spatial and temporal partitioning between the two species; there was a significant difference in the occurrences of the two species at individual cameras and T. stigmatica had a different activity schedule than T. thetis in wet sclerophyll forest, where the latter reached its greatest rate of occurrence. At a finer (camera station) scale, occurrences of T. thetis increased with proximity to roads and grassy edges and at sites that were less rocky and less steep. T. stigmatica occurrence increased in the presence of rainforest elements like vines, palms and ferns, more ground-level cover and tree-fall gaps and at sites with fewer emergent eucalypts. Conclusion: Our findings have implications for managing these pademelons and their habitats. T. thetis is a common species that was encountered more often than T. stigmatica, and it responded positively to human disturbance like roadsides and grassy edges, presumably because these areas provided good grazing opportunities. By comparison, T. stigmatica is a threatened species, and it responded to natural disturbance like tree-fall gaps where lateral cover was greater, and where rainforest food plants may be more abundant. Our results suggest, therefore, that conservation of the threatened T. stigmatica requires the preservation of intact rainforest.


Asunto(s)
Ecosistema , Bosques , Macropodidae , Macropodidae/fisiología , Animales , Nueva Gales del Sur , Simpatría , Bosque Lluvioso
16.
Environ Microbiol Rep ; 16(3): e13251, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38778789

RESUMEN

We conducted a research campaign in a neotropical rainforest in Costa Rica throughout the drought phase of an El-Nino Southern Oscillation event to determine microbial community dynamics and soil C fluxes. Our study included nests of the leafcutter ant Atta cephalotes, as soil disturbances made by these ecosystem engineers may influence microbial drought response. Drought decreased the diversity of microbes and the abundance of core microbiome taxa, including Verrucomicrobial bacteria and Sordariomycete fungi. Despite initial responses of decreasing diversity and altered composition, 6 months post-drought the microbiomes were similar to pre-drought conditions, demonstrating the resilience of soil microbial communities to drought events. A. cephalotes nests altered fungal composition in the surrounding soil, and reduced both fungal mortality and growth of Acidobacteria post-drought. Drought increased CH4 consumption in soils due to lower soil moisture, and A. cephalotes nests decrease the variability of CH4 emissions in some soil types. CH4 emissions were tracked by the abundance of methanotrophic bacteria and fungal composition. These results characterize the microbiome of tropical soils across both time and space during drought and provide evidence for the importance of leafcutter ant nests in shaping soil microbiomes and enhancing microbial resilience during climatic perturbations.


Asunto(s)
Hormigas , Bacterias , Sequías , Hongos , Microbiota , Bosque Lluvioso , Microbiología del Suelo , Clima Tropical , Hormigas/microbiología , Hormigas/fisiología , Animales , Hongos/clasificación , Hongos/fisiología , Hongos/aislamiento & purificación , Costa Rica , Bacterias/clasificación , Bacterias/genética , Bacterias/aislamiento & purificación , Suelo/química , Bosques
17.
Proc Biol Sci ; 291(2023): 20240866, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38808444

RESUMEN

Patterns of habitat use directly influence a species' fitness, yet for many species an individual's age can influence patterns of habitat use. However, in tropical rainforests, which host the greatest terrestrial species diversity, little is known about how age classes of different species use different adjacent habitats of varying quality. We use long-term mist net data from the Amazon rainforest to assess patterns of habitat use among adult, adolescent (teenage) and young understory birds in forest fragments, primary and secondary forest at the Biological Dynamics of Forest Fragments Project in Brazil. Insectivore adults were most common in primary forest, adolescents were equally likely in primary and secondary forest, and all ages were the least common in forest fragments. In contrast to insectivores, frugivores and omnivores showed no differences among all three habitat types. Our results illustrate potential ideal despotic distributions among breeding populations of some guilds of understory birds where adult insectivores may competitively exclude adolescent individuals from primary forest. Secondary forest recovery appears to hold promise as a breeding habitat for frugivore and omnivore species but only as a pre-breeding habitat for insectivores, but as the forest ages, the demographic structure of bird populations should match that of primary forest.


Asunto(s)
Aves , Ecosistema , Bosque Lluvioso , Animales , Aves/fisiología , Brasil , Factores de Edad , Conducta Alimentaria
18.
Proc Biol Sci ; 291(2023): 20240138, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38808448

RESUMEN

A leading hypothesis for the evolution of large brains in humans and other species is that a feedback loop exists whereby intelligent animals forage more efficiently, which results in increased energy intake that fuels the growth and maintenance of large brains. We test this hypothesis for the first time with high-resolution tracking data from four sympatric, frugivorous rainforest mammal species (42 individuals) and drone-based maps of their predominant feeding trees. We found no evidence that larger-brained primates had more efficient foraging paths than smaller brained procyonids. This refutes a key assumption of the fruit-diet hypothesis for brain evolution, suggesting that other factors such as temporal cognition, extractive foraging or sociality have been more important for brain evolution.


Asunto(s)
Encéfalo , Dieta , Conducta Alimentaria , Animales , Encéfalo/fisiología , Dieta/veterinaria , Evolución Biológica , Frutas , Bosque Lluvioso , Primates/fisiología
19.
BMJ Open ; 14(5): e082381, 2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38719283

RESUMEN

INTRODUCTION: Wildfires and deforestation potentially have direct effects on multiple health outcomes as well as indirect consequences for climate change. Tropical rainforest areas are characterised by high rainfall, humidity and temperature, and they are predominantly found in low-income and middle-income countries. This study aims to synthesise the methods, data and health outcomes reported in scientific papers on wildfires and deforestation in these locations. METHODS AND ANALYSIS: We will carry out a scoping review according to the Joanna Briggs Institute's (JBI) manual for scoping reviews and the framework proposed by Arksey and O'Malley, and Levac et al. The search for articles was performed on 18 August 2023, in 16 electronic databases using Medical Subject Headings terms and adaptations for each database from database inception. The search for local studies will be complemented by the manual search in the list of references of the studies selected to compose this review. We screened studies written in English, French, Portuguese and Spanish. We included quantitative studies assessing any human disease outcome, hospitalisation and vital statistics in regions of tropical rainforest. We exclude qualitative studies and quantitative studies whose outcomes do not cover those of interest. The text screening was done by two independent reviewers. Subsequently, we will tabulate the data by the origin of the data source used, the methods and the main findings on health impacts of the extracted data. The results will provide descriptive statistics, along with visual representations in diagrams and tables, complemented by narrative summaries as detailed in the JBI guidelines. ETHICS AND DISSEMINATION: The study does not require an ethical review as it is meta-research and uses published, deidentified secondary data sources. The submission of results for publication in a peer-reviewed journal and presentation at scientific and policymakers' conferences is expected. STUDY REGISTRATION: Open Science Framework (https://osf.io/pnqc7/).


Asunto(s)
Cambio Climático , Conservación de los Recursos Naturales , Bosque Lluvioso , Incendios Forestales , Humanos , Clima Tropical , Literatura de Revisión como Asunto , Proyectos de Investigación
20.
J Environ Manage ; 360: 121191, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38759552

RESUMEN

Understanding the dynamics of urban landscapes and their impacts on ecological well-being is crucial for developing sustainable urban management strategies in times of rapid urbanisation. This study assesses the nature and drivers of the changing urban landscape and ecosystem services in cities located in the rainforest (Akure and Owerri) and guinea savannah (Makurdi and Minna) of Nigeria using a combination of remote sensing and socioeconomic techniques. Landsat 8 datasets provided spatial patterns of the normalised difference vegetation index (NDVI) and normalised difference built-up index (NDBI). A household survey involving the administration of a semi-structured questionnaire to 1552 participants was conducted. Diminishing NDVI and increasing NDBI were observed due to the rising trend of urban expansion, corroborating the perception of over 54% of the respondents who noted a decline in landscape ecological health. Residential expansion, agricultural practices, transport and infrastructural development, and fuelwood production were recognised as the principal drivers of landscape changes. Climate variability/change reportedly makes a 28.5%-34.4% (Negelkerke R2) contribution to the changing status of natural landscapes in Akure and Makurdi as modelled by multinomial logistic regression, while population growth/in-migration and economic activities reportedly account for 19.9%-36.3% in Owerri and Minna. Consequently, ecosystem services were perceived to have declined in their potential to regulate air and water pollution, reduce soil erosion and flooding, and mitigate urban heat stress, with a corresponding reduction in access to social services. We recommend that urban residents be integrated into management policies geared towards effectively developing and enforcing urban planning regulations, promoting urban afforestation, and establishing sustainable waste management systems.


Asunto(s)
Ecosistema , Bosque Lluvioso , Nigeria , Conservación de los Recursos Naturales , Pradera , Humanos , Urbanización , Guinea
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA