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1.
PLoS Pathog ; 17(6): e1009583, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34081744

RESUMO

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic reveals a major gap in global biosecurity infrastructure: a lack of publicly available biological samples representative across space, time, and taxonomic diversity. The shortfall, in this case for vertebrates, prevents accurate and rapid identification and monitoring of emerging pathogens and their reservoir host(s) and precludes extended investigation of ecological, evolutionary, and environmental associations that lead to human infection or spillover. Natural history museum biorepositories form the backbone of a critically needed, decentralized, global network for zoonotic pathogen surveillance, yet this infrastructure remains marginally developed, underutilized, underfunded, and disconnected from public health initiatives. Proactive detection and mitigation for emerging infectious diseases (EIDs) requires expanded biodiversity infrastructure and training (particularly in biodiverse and lower income countries) and new communication pipelines that connect biorepositories and biomedical communities. To this end, we highlight a novel adaptation of Project ECHO's virtual community of practice model: Museums and Emerging Pathogens in the Americas (MEPA). MEPA is a virtual network aimed at fostering communication, coordination, and collaborative problem-solving among pathogen researchers, public health officials, and biorepositories in the Americas. MEPA now acts as a model of effective international, interdisciplinary collaboration that can and should be replicated in other biodiversity hotspots. We encourage deposition of wildlife specimens and associated data with public biorepositories, regardless of original collection purpose, and urge biorepositories to embrace new specimen sources, types, and uses to maximize strategic growth and utility for EID research. Taxonomically, geographically, and temporally deep biorepository archives serve as the foundation of a proactive and increasingly predictive approach to zoonotic spillover, risk assessment, and threat mitigation.


Assuntos
Bancos de Espécimes Biológicos/organização & administração , Controle de Doenças Transmissíveis , Doenças Transmissíveis Emergentes/prevenção & controle , Redes Comunitárias/organização & administração , Vigilância em Saúde Pública/métodos , Animais , Animais Selvagens , Biodiversidade , Bancos de Espécimes Biológicos/normas , Bancos de Espécimes Biológicos/provisão & distribuição , Bancos de Espécimes Biológicos/tendências , COVID-19/epidemiologia , Controle de Doenças Transmissíveis/métodos , Controle de Doenças Transmissíveis/organização & administração , Controle de Doenças Transmissíveis/normas , Doenças Transmissíveis Emergentes/epidemiologia , Doenças Transmissíveis Emergentes/microbiologia , Doenças Transmissíveis Emergentes/virologia , Redes Comunitárias/normas , Redes Comunitárias/provisão & distribuição , Redes Comunitárias/tendências , Planejamento em Desastres/métodos , Planejamento em Desastres/organização & administração , Planejamento em Desastres/normas , Geografia , Saúde Global/normas , Saúde Global/tendências , Humanos , Contramedidas Médicas , Pandemias/prevenção & controle , Saúde Pública , Medição de Risco , SARS-CoV-2/fisiologia , Zoonoses/epidemiologia , Zoonoses/prevenção & controle
3.
Braz J Biol ; 83: e239642, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34133487

RESUMO

The knowledge of ant assemblages that occurs in Conservation Units in the Atlantic Forest domain is a priority, considering the number of endemic species and the impacts that this biome has been suffering. The aim of this study was to evaluate ant assemblages in the Turvo State Park, which is the largest conservation unit in the State of Rio Grande do Sul and presents an important role on biodiversity protection. Two samplings were conducted in 2019, one in the summer (January) and the other in the spring (November and December), at five sites 2 km apart, with pitfall traps (soil and canopy), sardine baits, glucose, beating net, sweeping net and manual collection. We sampled 121 species in the summer and 120 in the spring, totaling 163 ant species. A total of 78 species (47.8%) occurred in both sampling seasons. The richest genera in the study were Camponotus (S = 30), Pheidole (S = 23) and Linepithema (S = 11). Seventeen species were recorded for the first time for Rio Grande do Sul state. The results indicate that this is one of the most species-rich assemblages of ants ever surveyed in a conservation unit in southern Brazil. The study highlights the importance of Conservation Units as protected environments against habitat loss for ant biodiversity. The results of this study contribute to myrmecofauna knowledge and serve as a basis for environmental impact studies, management plans and conservation of Atlantic Forest remnants.


Assuntos
Formigas , Animais , Biodiversidade , Brasil , Ecossistema , Estações do Ano
4.
Braz J Biol ; 82: e238096, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34133555

RESUMO

Pakistan is the country with mega freshwater fish diversity of native and alien species. In the presence of enormous native fishes varies species of exotic fishes have been introduced into the freshwater bodies of Pakistan which are competing with native freshwater fish fauna and making them deprive of food and habitat as well. Intentional or accidental introductions of animals, plants and pathogens away from their native niche is considered as major leading problem for biodiversity of invaded habitat. Three years study (from January 2017 to December 2019) was conducted in freshwater bodies of Province Punjab, Pakistan. Study was designed to know exotic species impacts on the distribution of native species of fishes. During current survey a total of 68 (indigenous and exotic) fish species belonging to 14 families were recorded from head Qadirabad, head Baloki, Islam headworks and Rasul barrage. Statistical analysis showed that Shannon-Wiener diversity index was the highest (1.41) at both Rasul barrage and Islam headworks but, invasive species were present in very less number in these study sites i.e. Oreochromis mozambicus, O. niloticus, Hypophthalmichthys nobilis, Carassius auratus, Ctenophryngdon idella, Cyprinus carpio and H. molitrix. The diversity index showed that comparatively low diversity was present in both area head Qadirabad (1.30) and head Baloki (1.4) due to high pressure of invasive species. Direct observation of species and statistical analysis showed that aliens' species produced negative impact on the local fish fauna diversity, evenness, and numbers. It is concluded that many factors are impacts on the diversity of native fishes, but alien (invasive) species also play a major role to reduction of native species, because aliens' species produce competition for native species. So it is urgent need to analysis the aliens and native food web and roosting sites in Pakistan, in future.


Assuntos
Carpas , Espécies Introduzidas , Animais , Biodiversidade , Ecossistema , Peixes , Água Doce , Paquistão
5.
Environ Monit Assess ; 193(7): 413, 2021 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-34117940

RESUMO

The use of indicator species can simplify bird monitoring by reducing the level of specialized skills needed, which increases the potential pool of participants and reduces training costs and complexity. To facilitate monitoring in the humid forests of northeast Central America, we conducted point count surveys for birds across gradients of disturbance in the Cockscomb Basin Wildlife Sanctuary, Belize, and analyzed the association of bird species with remotely sensed metrics of forest condition and anthropogenic disturbance using indicator species analysis. Twenty species exhibited significant associations with one or more of these metrics. We propose six species as indicators for anthropogenic disturbance based on our criteria of being associated with anthropogenically disturbed sites, or anthropogenically disturbed and riparian sites with no explicit mention in the literature of an obligate association with riparian habitats, or association of remotely sensed metrics that appeared to reflect disturbance: yellow-olive flycatcher, red-legged honeycreeper, dusky antbird, blue ground dove, buff-throated saltator, and brown jay. We propose the keel-billed motmot as an indicator of undisturbed forest based on its association with forested sites in our analyses. Green shrike vireo, collard trogon, rufous-tailed jacamar, and rufous piha were associated with a specific elevational range but not associated with disturbance, so upward shifts in elevation that might indicate response to climate change would not be confounded with habitat disturbance or degradation. This exercise yielded a much-reduced list of monitoring targets, which will greatly reduce the cost and complexity of forest bird monitoring in the region, as well as reducing barriers to participation.


Assuntos
Aves , Monitoramento Ambiental , Animais , Belize , Biodiversidade , América Central , Ecossistema , Florestas , Humanos
6.
Sci Total Environ ; 784: 147172, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34088022

RESUMO

One of the biggest challenges to deal with the global crisis of biodiversity loss is the lack of efficient and viable monitoring systems across scales. Unlike traditional in situ biodiversity monitoring, a usually costly and time-consuming enterprise, satellite remote sensing (SRS) data offer a technically feasible and sustainable in time solution. Here, we devise a cost-effective and upgradeable spatiotemporal framework for monitoring the species-specific habitat availability changes across scales by trend analysis of habitat suitability index (HSI) derived from ecological niche models (ENMs; Maxent) and using time series of SRS data (MODIS). The SRS-ENM framework was applied for a large suite of native species (911), from major taxonomic groups (flora (vascular plants), amphibians, reptiles, birds and mammals), and listed in the IUCN Red List at regional (Iberian Peninsula) and continental (Europe) scales. The HSI-trend analyses predict cumulative reductions in habitat suitability for Threatened and Non-Threatened species across scales for the period 2002-2016. Specifically, 19% and 66% of the total grid cells for both species' groups showed negative trends at both regional and continental scales, respectively. Results were similar when considering all IUCN threat categories. All taxa groups showed a decrease in habitat suitability, but amphibians and reptiles groups hosted the largest number of negative HSI-trends grid cells. Considering all groups together, 12% and 34% of both study areas have strong reductions in habitat quality. We conclude that our framework detects increases and decreases in species' habitat suitability regardless of the spatial scale, extent, and pixel size. Species' range predictions across space and time based on SRS time series represent a promising Earth observation tool to support traditional risk assessment protocols and anticipate the decision-making process, while serving as a cross-scale biodiversity monitoring system.


Assuntos
Biodiversidade , Ecossistema , Anfíbios , Animais , Aves , Conservação dos Recursos Naturais , Europa (Continente)
7.
Sci Total Environ ; 783: 146910, 2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34088134

RESUMO

Human activities have enormous impact on current biodiversity distribution across all spatial scales. Despite the numerous studies showing the difference between preserved and impaired sites, only little is known about the regional scale. Therefore, we selected four European regions differing in habitat conservation status (HCS) to explore if the variation in land snail communities reflects regional differences. We collected quantitative land snail samples at 169 isolated spring fen sites and measured environmental parameters. The species richness of habitat specialists expressed low variation and weak associations with local conditions in the two regions of adequate HCS, presumably because of their common occurrence throughout most sites. In contrast, the richness of matrix-derived species, i.e. predominantly habitat generalists, was highly variable in these two regions and also tightly associated with local conditions, especially moisture. In both the intermediate and the inadequate HCS region, these associations were much weaker as the fens are less extreme and allow for penetration of matrix-derived species. Population densities of Vertigo geyeri, an umbrella species internationally protected by the EU Habitats Directive, were highest in the two adequate HCS regions. Species composition was primarily controlled by moisture in the regions of adequate HCS, while in the remaining regions, those predictors that are less easily jeopardized by human impact, such as climate, water chemistry and terrain topography, gained importance. In the inadequate HCS region, none of the analysed predictors was associated with the main compositional gradient, suggesting a complete disruption of community-environment relationships. Our results suggest that the species richness and community responses to natural gradients might be substantially modified by human impact, although the effect of some other region-specific factors cannot be easily disentangled because of inevitably low number of studied regions.


Assuntos
Biodiversidade , Ecossistema , Animais , Clima , Humanos , Estações do Ano , Caramujos
8.
Braz J Biol ; 82: e236345, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34105665

RESUMO

A first checklist of Rotifera species in freshwater environments in Bahia State, in northeastern Brazil, is provided. The list includes sampling data from 26 aquatic environments (lotic and lentic) undertaken from 2010 to 2016. One hundred and fifty-five species were recorded, with 68 new records for the state. The family Brachionidae and Lecanidae were the most representative (54.8%). The greatest richness was recorded in the Colônia River (57 species). Those results reflect the low numbers of studies previously undertaken in the region, indicating more research needs to be focused on Rotifera biodiversity in Bahia, the fifth largest state in Brazil (567,295 km2) with large numbers of freshwater bodies.


Assuntos
Rotíferos , Animais , Biodiversidade , Brasil , Água Doce , Rios
9.
Nat Commun ; 12(1): 3381, 2021 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-34099669

RESUMO

Nutrient amendment diminished bacterial functional diversity, consolidating carbon flow through fewer bacterial taxa. Here, we show strong differences in the bacterial taxa responsible for respiration from four ecosystems, indicating the potential for taxon-specific control over soil carbon cycling. Trends in functional diversity, defined as the richness of bacteria contributing to carbon flux and their equitability of carbon use, paralleled trends in taxonomic diversity although functional diversity was lower overall. Among genera common to all ecosystems, Bradyrhizobium, the Acidobacteria genus RB41, and Streptomyces together composed 45-57% of carbon flow through bacterial productivity and respiration. Bacteria that utilized the most carbon amendment (glucose) were also those that utilized the most native soil carbon, suggesting that the behavior of key soil taxa may influence carbon balance. Mapping carbon flow through different microbial taxa as demonstrated here is crucial in developing taxon-sensitive soil carbon models that may reduce the uncertainty in climate change projections.


Assuntos
Ciclo do Carbono , Mudança Climática , Nutrientes/metabolismo , Microbiologia do Solo , Solo/química , Acidobacteria/genética , Acidobacteria/isolamento & purificação , Acidobacteria/metabolismo , Biodiversidade , Bradyrhizobium/genética , Bradyrhizobium/isolamento & purificação , Bradyrhizobium/metabolismo , Carbono/metabolismo , DNA Bacteriano/isolamento & purificação , Monitorização de Parâmetros Ecológicos/métodos , Previsões/métodos , Fósforo/metabolismo , RNA Ribossômico 16S/genética , Streptomyces/genética , Streptomyces/isolamento & purificação , Streptomyces/metabolismo
10.
Nat Commun ; 12(1): 2995, 2021 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-34016962

RESUMO

Studies along elevational gradients worldwide usually find the highest plant taxa richness in mid-elevation forest belts. Hence, an increase in upper elevation diversity is expected in the course of warming-related treeline rise. Here, we use a time-series approach to infer past taxa richness from sedimentary ancient DNA from the south-eastern Tibetan Plateau over the last ~18,000 years. We find the highest total plant taxa richness during the cool phase after glacier retreat when the area contained extensive and diverse alpine habitats (14-10 ka); followed by a decline when forests expanded during the warm early- to mid-Holocene (10-3.6 ka). Livestock grazing since 3.6 ka promoted plant taxa richness only weakly. Based on these inferred dependencies, our simulation yields a substantive decrease in plant taxa richness in response to warming-related alpine habitat loss over the next centuries. Accordingly, efforts of Tibetan biodiversity conservation should include conclusions from palaeoecological evidence.


Assuntos
Biodiversidade , DNA Antigo/análise , DNA de Plantas/análise , Aquecimento Global , Plantas/genética , Altitude , Código de Barras de DNA Taxonômico , Ecologia/métodos , Florestas , Paleontologia/métodos , Tibet
11.
Ecol Lett ; 24(7): 1455-1466, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33979477

RESUMO

Priority effects can play a fundamental role in the assembly of ecological communities, but how they shape the dynamics of biodiversity over macroevolutionary timescales remains unclear. Here we develop and analyse a metacommunity model combining local priority effects with niche evolution, speciation and extinction. We show that by promoting the persistence of rare species, local priority effects cause the evolution of higher metacommunity diversity as well as major disparities in richness among evolutionary lineages. However, we also show how classic macroevolutionary patterns of niche incumbency-whereby rates of regional diversification and invasion slow down as ecological niches are filled-do not depend on local priority effects, arising even when invading species continuously displace residents. Together, these results clarify the connection between local priority effects and the filling of ecological niche space, and reveal how the impact of species arrival order on competition fundamentally shapes the generation and maintenance of biodiversity.


Assuntos
Biodiversidade , Evolução Biológica , Biota , Ecossistema , Especiação Genética , Filogenia
12.
Environ Monit Assess ; 193(Suppl 1): 270, 2021 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-33988766

RESUMO

The plot-level decisions of land managers (i.e., farmers, ranchers, and forest owners) influence landscape-scale environmental outcomes for biodiversity in agricultural landscapes. The impacts of their decisions often develop in complex, non-additive ways that unfold over time and space. Behavioral science offers insights into ways decision-makers manage complexity, uncertainty, choice over time, and social influence. We review such insights to understand the plot-level conservation actions of farmers that impact biodiversity. To make these connections concrete, we provide a case study of the decision to adopt biodiversity management practices in the heavily cultivated region of the Central Valley, California, USA. We use results from a survey of 122 farmers in the region to test whether adoption is related to farm tenure arrangements or peer influence. We find farmers who are more sensitive to peer influence are three times more likely to adopt practices that support biodiversity, including wildflowers, native grasses, cover crops, hedgerows, and wetlands. This relationship could have important implications for how plot-level decisions aggregate to landscape-scale outcomes. Finally, we suggest priorities for future research and program design to integrate behavioral science into biodiversity conservation in agricultural landscapes. By considering land managers' plot-level conservation decisions with the lens of behavioral science, we identify barriers and opportunities to promote environmental benefits.


Assuntos
Ciências do Comportamento , Conservação dos Recursos Naturais , Agricultura , Biodiversidade , California , Monitoramento Ambiental
13.
Environ Monit Assess ; 193(Suppl 1): 75, 2021 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-33988768

RESUMO

Over the last decades, land management options have been investigated that aim at enhancing services to agriculture delivered by biodiversity and its associated biotic interactions. Such services can be promoted through land management strategies ranging from in-field single agricultural practices, long-term strategies compiling these agricultural practices at the crop rotation scale, to management strategies at the landscape scale. In this paper, we provide an overview of the land management options that can be implemented at multiple scales, with a specific focus on the provision of one service that is key in agriculture, i.e. pest control. We present existing knowledge and highlight current gaps and limitations in our understanding of pest control response to land management. Based on this analysis, we propose two promising and complementary research approaches that could help filling existing knowledge gaps and provide guidelines for designing landscapes for agroecological services: (1) landscape monitoring networks (LMN), based on long-term monitoring of ecological and managerial processes within sets of landscapes located in contrasted production contexts; (2) agroecological system experiments (ASE), which design and assess combinations of land management options at multiple embedded spatial scales.


Assuntos
Monitoramento Ambiental , Controle Biológico de Vetores , Agricultura , Biodiversidade , Ecossistema
14.
Proc Biol Sci ; 288(1950): 20210545, 2021 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-33975476

RESUMO

Many ecological and evolutionary hypotheses have been proposed to explain the latitudinal diversity gradient, i.e. the increase in species richness from the poles to the tropics. Among the evolutionary hypotheses, the 'out of the tropics' (OTT) hypothesis has received considerable attention. The OTT posits that the tropics are both a cradle and source of biodiversity for extratropical regions. To test the generality of the OTT hypothesis, we explored the spatial biodiversity dynamics of unicellular marine plankton over the Cenozoic era (the last 66 Myr). We find large-scale climatic changes during the Cenozoic shaped the diversification and dispersal of marine plankton. Origination was generally more likely in the extratropics and net dispersal was towards the tropics rather than in the opposite direction, especially during the warmer climates of the early Cenozoic. Although migration proportions varied among major plankton groups and climate phases, we provide evidence that the extratropics were a source of tropical microplankton biodiversity over the last 66 Myr.


Assuntos
Biodiversidade , Plâncton , Clima
15.
Nat Commun ; 12(1): 2762, 2021 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-33980851

RESUMO

The Mediterranean basin is a hotspot of biodiversity, fuelled by climatic oscillation and geological change over the past 20 million years. Wall lizards of the genus Podarcis are among the most abundant, diverse, and conspicuous Mediterranean fauna. Here, we unravel the remarkably entangled evolutionary history of wall lizards by sequencing genomes of 34 major lineages covering 26 species. We demonstrate an early (>11 MYA) separation into two clades centred on the Iberian and Balkan Peninsulas, and two clades of Mediterranean island endemics. Diversification within these clades was pronounced between 6.5-4.0 MYA, a period spanning the Messinian Salinity Crisis, during which the Mediterranean Sea nearly dried up before rapidly refilling. However, genetic exchange between lineages has been a pervasive feature throughout the entire history of wall lizards. This has resulted in a highly reticulated pattern of evolution across the group, characterised by mosaic genomes with major contributions from two or more parental taxa. These hybrid lineages gave rise to several of the extant species that are endemic to Mediterranean islands. The mosaic genomes of island endemics may have promoted their extraordinary adaptability and striking diversity in body size, shape and colouration, which have puzzled biologists for centuries.


Assuntos
Introgressão Genética , Genoma/genética , Lagartos/genética , Animais , Biodiversidade , Evolução Molecular , Variação Genética , Lagartos/classificação , Ilhas do Mediterrâneo , Filogenia
16.
Ecotoxicology ; 30(5): 986-995, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33991262

RESUMO

Coral reef ecosystems usually distribute in oligotrophic tropical and subtropical marine environments, but they possess great biodiversity and high productivity. It may attribute to its efficient internal nutrient cycle system. However, the knowledge of functional microbial community structure is still limited. In this study, both functional gene array (Geochip 5.0) and nifH Illumina sequencing were used to profile the overall functional genes and diazotrophic communities associated with coral Porites pukoensis. More than 7500 microbial functional genes were detected from archaea, bacteria, and fungi. Most of these genes are related to the transformation of carbon, nitrogen, sulfur, and phosphorus, providing evidence that microbes in the coral holobiont play important roles in the biogeochemical cycle of coral reef ecosystems. Our results indicated a high diversity of diazotrophs associated with corals. The dominant diazotrophic groups were related to phyla Alphaproteobacteria, Deltaproteobacteria, Cyanobacteria, and Gammaproteobacteria. And the dominant diazotrophic communities were divided into four clusters. They were affiliated with nifH sequences from genera Zymomonas, Halorhodospira, Leptolyngbya, Trichormus, and Desulfovibrio, indicating these groups may play a more important role in the nitrogen-fixing process in the coral holobiont. This study revealed functional gene diversity and suggested the roles they played in the biogeochemical cycling of the coral holobiont.


Assuntos
Antozoários , Animais , Antozoários/genética , Archaea , Biodiversidade , Recifes de Corais , Fungos
17.
Sci Total Environ ; 779: 146233, 2021 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-34030248

RESUMO

The biogeochemical processes, anaerobic oxidation of methane (AOM) and methanogenesis, control methane emission and create distinct geochemical profiles with depth in marine sediments. Correlating the capacities and biodiversity of the microbial communities in marine sediments remains challenging. We therefore investigated the geochemical constituents and the capabilities and diversity of microbial communities in sediments at different depths in two cores from the Shenhu area in the northern South China Sea, which is characterized by underlying gas hydrates. The geochemical features, sulfate concentration decreased linearly and the acid volatile sulfur accumulated from 4 m below the seafloor (mbsf) to the bottom, indicating significant sulfate reduction. However, the methane concentration was relatively low and showed irregular trends, indicating that our study cores did not reach the sulfate-methane transition zone (SMTZ). Nevertheless, incubation experiments showed that the microbial groups in sediments performed AOM and methanogenesis in the region where sulfate decreased linearly above the SMTZ. We mapped the diversity and abundance of microbial communities in sediments with depth using high-throughput sequencing. A small proportion of known methanogens (<0.3%) may have been responsible for the methanogenesis during incubation. No classical archaeal anaerobic methanotroph (ANME) sequences were detected across all samples; only a small amount of SEEP-SRB1 were detected, and their abundance did not increase with increasing depth. Thus, unknown or unconventional phylotypes may have participated in AOM during the incubation, and the dominant phylum Bathyarchaeota or the small number of detected methanogens are the most likely performers of AOM.


Assuntos
Sedimentos Geológicos , Microbiota , Archaea/genética , Biodiversidade , China , Metano , Oxirredução , Filogenia , RNA Ribossômico 16S
18.
Sci Total Environ ; 780: 146630, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34030303

RESUMO

Hydrology and microtopography are important factors affecting the structure and function of wetland ecosystems and controlling plant community distribution and succession. This study aims to identify the effects of hydrology and microtopography on the structure and function of a wetland plant community. A field survey was conducted in Carex schmidtii tussock wetland. Vegetation was sampled in different microtopographic regions (hummock and interspaces) in three types of tussock wetlands with different hydrological conditions (i.e., droughty, seasonally flooded and long-term flooded). Relative importance value (RIV), species richness, diversity, dominance, as well as community similarity and productivity were calculated. We recorded a total of 52 species of plants, belonging to 21 families and 39 genera, in sample plots. Community ecological characteristics significantly differed under varying hydrological conditions and microtopographic regions. Drought decreased the dominance of the C. schmidtii community but increased the frequency of mesophytes. Species richness and diversity in seasonally and long-term flooded sites were significantly lower than droughty sites, while community dominance and productivity in these areas were significantly higher than in droughty sites. Biodiversity in hummocks was significantly lower than in interspaces, but with higher community dominance and productivity. In droughty sites, C. schmidtii on hummocks lost its dominance, resulting in higher community similarity between hummocks and interspaces. Conversely, in seasonally and long-term flooded sites, C. schmidtii on hummocks was absolutely dominant with RIV of 77.0 ± 2.78% and low community similarity between hummocks and interspaces. Moreover, hummock community structure was more similar to that of the overall community, and C. schmidtii biomass in hummocks was the main source of community productivity, indicating the supporting effects of hummocks on community structure. In conclusion, hydrology and microtopography jointly affect the plant community. Attention should be paid to the protection and maintenance of hummock structure and the dominance of C. schmidtii communities in tussock wetland conservation and management.


Assuntos
Carex (Planta) , Áreas Alagadas , Biodiversidade , Ecossistema , Humanos , Hidrologia
19.
Sci Total Environ ; 780: 146140, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34030316

RESUMO

The introduction of temporary grassland into an annual crop rotation is recognized to improve soil ecosystem services, and resulting legacies can be beneficial for the following crops. In this context, the aim of the present study was to evaluate legacy effects of introducing temporary grassland into an annual crop rotation on five ecosystem services (i) soil structure maintenance (aggregate stability), (ii) water regulation (saturated hydraulic conductivity), (iii) biodiversity conservation (microbial biomass and microbial metabolic activity, as well as microorganism, enchytraeid, springtail and earthworm communities), (iv) pathogen regulation (soil suppressiveness to Verticillium dahliae), and (v) forage production and quality. Three crop rotation schemes, maintained for twelve years, were compared in four random blocks, one being an annual crop rotation without grassland (0%), another with a medium percentage of grassland (50%, corresponding to 3 years of continuous grassland in the crop rotation), and a third one with a high percentage of grassland in the crop rotation (75%, corresponding to 6 years of continuous grassland in the crop rotation). The results showed that the grassland introduction into an annual crop rotation improved, whatever the duration of the grassland, soil structure maintenance and biodiversity conservation, while it decreased pathogen regulation and did not modify water regulation. Comparing the two crop rotations that included grassland, indicated a stronger beneficial grassland legacy effect for the higher proportion of grassland concerning soil structure maintenance and biodiversity conservation. By contrast, water regulation, pathogen regulation and forage production were not affected by the legacy of the 75% grassland during the rotation. Overall, our findings demonstrated the extent to which grassland legacies are affecting the current state of soil properties and possible ecosystem services provided. To improve ecosystem services, soil management should take legacy effects into account and consider longer timeframes to apply beneficial practices.


Assuntos
Ecossistema , Solo , Agricultura , Ascomicetos , Biodiversidade , Produção Agrícola , Pradaria
20.
Sci Total Environ ; 780: 146674, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34030338

RESUMO

Although the relationship between biodiversity and ecosystem functioning has been extensively studied, it remains unclear if the relationships of biodiversity with productivity and its spatial stability vary along productivity gradients in natural ecosystems. Based on a large dataset from 2324 permanent forest inventory plots across northeastern China, we examined the intensity of species richness (SR) and tree size diversity (Hd) effects on aboveground wood productivity (AWP) and its spatial stability among different productivity levels. Structural equation modeling was applied, integrating abiotic (climate and soil) and biotic (stand density) factors. Our results demonstrated that both SR and Hd positively affected AWP and its spatial stability, and the intensity of these positive effects decreased with increasing productivity. At low productivity levels, SR and Hd increased spatial stability by reducing spatial variability and increasing mean AWP. At high productivity levels, stability increased only through mean AWP increase. Moreover, temperature and stand density affected the AWP directly and indirectly via biodiversity, and the strength and direction of these effects varied among different productivity levels. We concluded that biodiversity could simultaneously enhance productivity and its spatial stability in temperate forests, and that the effect intensity was uniform along productivity gradients, which provided a new perspective on relationships within biodiversity-ecosystem functioning.


Assuntos
Ecossistema , Florestas , Biodiversidade , Biomassa , China , Árvores
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