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opencc-zeroApr 2022View details →

Direct and indirect effects of fire on microbial communities in a pyrodiverse dry-sclerophyll forest

Fire is one of the predominant drivers of the structural and functional dynamics of forest ecosystems. In recent years, novel fire regimes have posed a major challenge to the management of pyrodiverse forests. While previous research efforts have focused on quantifying the impacts of fire on above-ground forest biodiversity, how microbial communities respond to fire is less understood, despite their functional significance. Here, we describe the effects of time since fire, fire frequency and their interaction on soil and leaf litter fungal and bacterial communities from the pyrodiverse, Eucalyptus pilularis forests of south-eastern Australia. Using structural equation models, we also elucidate how fire can influence these communities both directly and indirectly through biotic-abiotic interactions. Our results demonstrate that fire is a key driver of litter and soil bacterial and fungal communities, with effects most pronounced for soil fungal communities. Notably, recently burnt forest hosted lower abundances of symbiotic ectomycorrhizal fungi and Acidobacteria in the soil, and basidiomycetous fungi and Actinobacteriota in the litter. Compared with low fire frequencies, high fire frequency increased soil fungal plant pathogens, but reduced Actinobacteriota. The majority of fire effects on microbial communities were mediated by fire-induced changes in litter and soil abiotic properties. For instance, recent and more frequent fire was associated with reduced soil sulphur, which led to an increase in soil fungal plant pathogens and saprotrophic fungi in these sites. Pathogenic fungi also increased in recently burnt forests that had a low fire frequency, mediated by a decline in litter carbon and an increase in soil pH in these sites. Synthesis. Our findings indicate that predicted increases in the frequency of fire may select for specific microbial communities directly and indirectly through ecological interactions, which may have functional implications for plants (increase in pathogens, decrease in symbionts), decomposition rates (declines in Actinobacteriota and Acidobacteriota) and carbon storage (decrease in ectomycorrhizal fungi). In the face of predicted shifts in wildfire regimes, which may exacerbate fire-induced changes in microbial communities, adaptive fire-management and monitoring is required to address the potential functional implications of fire-altered microbial communities.

opencc-zeroAug 2022View details →

Data from: Disentangling direct from indirect effects of habitat disturbance on multiple components of biodiversity

Human habitat disturbance affects both species diversity and intraspecific genetic diversity, leading to correlations between these two components of biodiversity (termed species - genetic diversity correlation, SGDC). However, whether SGDC predictions extend to host-associated communities, such as the intestinal parasite and gut microbial diversity, remains largely unexplored. Additionally, the role of dominant generalist species is often neglected despite their importance in shaping the environment experienced by other members of the ecological community, and their role as source, reservoir and vector of zoonotic diseases. New analytical approaches (e.g., structural equation modelling, SEM) can be used to assess SGDC relationships and distinguish among direct and indirect effects of habitat characteristics and disturbance on the various components of biodiversity. With six concrete and biologically sound models in mind, we collected habitat characteristics of 22 study sites from four distinct landscapes located in central Panama. Each landscape differed in the degree of human disturbance and fragmentation measured by several quantitative variables, such as canopy cover, canopy height and understory density. In terms of biodiversity, we estimated on the one hand, 1) small mammal species diversity, and, on the other hand, 2) genome-wide diversity, 3) intestinal parasite diversity and 4) gut microbial heterogeneity of the most dominant generalist species (Tome's spiny rat, Proechimys semispinosus). We used SEMs to assess the links between habitat characteristics and biological diversity measures. The best supported SEM suggested that habitat characteristics directly and positively affect the richness of small mammals, the genetic diversity of P. semispinosus and its gut microbial heterogeneity. Habitat characteristics did not, however, directly impact intestinal parasite diversity. We also detected indirect, positive effects of habitat characteristics on both host-associated assemblages via small mammal richness. For microbes, this is likely linked to cross species transmission, particularly in shared and/or anthropogenically altered habitats, whereas host diversity mitigates parasite infections. The SEM revealed an additional indirect but negative effect on intestinal parasite diversity via host genetic diversity. Our study showcases that habitat alterations not only affect species diversity and host genetic diversity in parallel, but also species diversity of host-associated assemblages. The impacts from human disturbance are therefore expected to ripple through entire ecosystems with far reaching effects felt even by generalist species.

opencc-zeroOct 2022View details →

Data for: Direct and indirect effects of management and landscape on biological pest control and crop pest infestation in apple orchards

Biological pest control, relying on naturally occurring predator-prey dynamics, is considered a key element to achieve more sustainable farming systems. However, the combined effects of local management and landscape factors on communities of natural enemies as well as the cascading effects on pest infestations are rarely addressed, especially in perennial crops. Here, we used Piecewise Structural Equation Modelling (PSEM) to test direct and indirect effects of landscape composition, landscape configuration and local management practices on natural enemy communities, the pest control services they provide and ultimately on pest infestation and pest-related yield damage in apple crops. To this end, we surveyed 12 organic and 12 Integrated Pest Management (IPM) orchards during three consecutive years, and we also established a semi-natural benchmark to quantify the extent to which predator communities in the orchards were degraded. Natural enemies had a different community composition and were more abundant in organic orchards compared to IPM orchards. This had a small and positive effect on sentinel egg predation rates in organic orchards, but overall had very little impact on actual apple pest infestation. On the contrary, apple pest infestation levels were directly and positively affected by organic management practices and by increasing semi-natural habitat cover and landscape edge density. Compared to a semi-natural benchmark, both agricultural management systems showed degraded predator communities, which translated into an impaired delivery of biological control services. Synthesis and applications. Our results indicate that organic management and habitat conservation can enhance natural enemies and stimulate pest control, but also show that these factors can enhance pest infestations and can even lead to an overall increase in pest-related crop damage. Our study thus highlights the complex interplay of ecosystem services and disservices provided by biodiversity, which should be taken into account when advising farmers, policy makers and land managers on effective and sustainable strategies to control pest species and safeguard crop production.

opencc-by-4.0Apr 2024View details →

Constraining light absorption of brown carbon in China and implications for aerosol direct radiative effect

Brown carbon (BrC) in China is of great interest to the regional and global climate due to its strong absorption of sunlight. However, the contribution of BrC to total carbonaceous aerosol light absorption and its direct radiative effects (DRE) in China remains largely uncertain. To better assess its climate impact in China, we develop an explicit BrC scheme and implement it in a global climate model, which includes optical parameters of primary BrC derived from local measurements, secondary BrC absorption, and a photobleaching parameterization of BrC. By comparing with multi-type observational data, we find that with the implementation of this scheme, the model captures the seasonal variations of BrC light absorption well in China. The model estimates that BrC contributes 19% and 12% to the total light absorption of carbonaceous aerosol in China in winter and summer, resulting in 0.110 W m-2 and 0.205 W m-2 of DRE, respectively.

opencc-by-4.0Oct 2018View details →

Online Resources Chapter 3 - Decomposition of standing litter biomass in newly constructed wetlands associated with direct effects of sediment and water characteristics and the composition and activity of the decomposer community using Phragmites australis as a single standard substrate

Online Resources to Chapter 3 "Decomposition of standing litter biomass in newly constructed wetlands associated with direct effects of sediment and water characteristics and the composition and activity of the decomposer community using Phragmites australis as a single standard substrate" of PhD thesis from Ciska Overbeek, "Peat formation on a former landfill - Production and decomposition of aquatic pioneer vegetation".  Published by Overbeek et al in 2019 in Wetlands 39(1): 113-125. https://doi.org/10.1007/s13157-018-1081-y.

opencc-by-4.0Dec 2018View details →

New Zealand native forest plant cover data for Popovic et al. MEE (2019), Untangling direct species associations from indirect mediator species effects with graphical models.

Forest cover measurements were collected at 1246 native forest sites that form part of a network of permanent 20 x 20 m plots spread throughout New Zealand. A total of 1831 plant species were present in these plots, with the most common being herbs, graminoids, ferns, shrubs and trees. Plant cover (in ordinal categories) was assessed for each species in several tiers at different heights. The cover data we analysed (NZ_native_forest_cover.csv) were the maximum cover recorded over all the tiers at the 964 sites identified as native forests, containing 1311 species with at least one presence. NZ_native_forest_species.csv contains species data including species name, exotic/native, and plant type (tree, shrub, etc.), corresponding to the plant species in the columns of NZ_native_forest_cover.csv. We acknowledge the use of data drawn from the Natural Forest plot data collected between January 2002 and March 2007 by the LUCAS programme for the Ministry for the Environment, New Zealand.

opencc-zeroJun 2021View details →

Data from: Direct and indirect effects of landscape and field management intensity on carabids through trophic resources and weeds

Carabids are important biological control agents of weeds and other pests in agricultural fields. The carabid community is built upon direct and indirect ecological effects of landscape complexity, field management intensity and biotic components that in interaction make any prediction of community size and composition challenging. We analyse a large-scale sample of 60 European cereal fields using Structural Equation Modelling to quantify the direct effects of field management intensity and the surrounding landscape, and their indirect effect via biotic components, on carabid diversity. Our results highlight that direct and indirect effects of increasing landscape complexity, mediated by trophic resources, mainly affect carabids positively. Field management intensity only ever affects carabids through indirect effects that are generally negative, by suppressing standing weeds and weed seeds. Indirect effects on granivore carabid species depended on weed seed availability whereas omnivores depended on the availability of both weed seeds and animal prey. Synthesis and applications: A consideration of both the direct and indirect effects of landscape and field management is necessary for predicting carabid communities and with interactions. These effects, mediated via trophic resources, supports the diversity and abundance of carabid communities and their provision of ecosystem services. Our results show that promoting crop diversity and connectivity to semi-natural habitats will directly enhance carabid communities in farmland by manipulating their migration from source habitats. A reduction in field management intensity will preserve local standing weeds and weed seeds, and indirectly support carabid communities. These local and landscape modifications could contribute to improve the natural regulation of pests and weeds by carabids.

opencc-zeroJul 2023View details →

Data from: Direct and indirect effects of urbanization, pesticides, and wild insect pollinators on mango yield

<ol> <li>Expanding cities increasingly encroach fertile farmlands, questioning the viability of maintaining agriculture within and around them. Yet, our knowledge on how urbanization influences pollinator communities and the provision of pollination services to crops is limited, especially for the urbanization hotspots of the Global South. </li> <li>Mango (Mangifera indica) is one of the most important fruit crops in tropical countries. To analyze the dependency of mango on its main insect pollinators, and the direct and indirect effects of urbanization and insecticides on pollinator abundance and mango yield, we conducted a pollinator exclusion experiment and sampled flower visitors on 16 mango farms spread across rural-urban landscapes in Bengaluru, a South Indian megacity. </li> <li>We found that allowing flowers access to ants and flying visitors (bees, hoverflies, non-syrphid flies), dramatically increased mango yield by 350%, highlighting the importance of wild insects for mango pollination. We detected a trend between wild bee abundance and the final fruit set, with an increase of 20% when the number of bees increased from 25 to 125. </li> <li>Urbanization did not directly affect pollinator abundance or mango yield. However, the amount of insecticide applications had strong negative effects on wild bee abundance at low and intermediate levels of urbanization, while it had no effect in highly urbanized areas, presumably because of higher availability of flowering resources. Moreover, the amount of insecticides decreased the weight of harvested mango fruits by almost 30%. This may indicate trade-offs between conventional pest control and enhanced crop yields through pollination by wild insects in rural areas. </li> <li> Synthesis and applications. Our results indicate that mango production can be maintained at a profitable level in urbanized landscapes with insect pollinators more than tripling final yield. However, increasing use of insecticides, besides raising farmers' expenses, can have negative effects on wild insect pollinators and mango yield, especially in rural areas. To safeguard crucial pollination services, it is therefore critical to conserve and promote wild insect pollinators by minimizing the negative effects of insecticide applications in these areas. </li> </ol>

opencc-zeroJul 2023View details →

Data from: Direct and indirect effects of a fishing ban on lacustrine fish community do not result in a full recovery

<ol> <li>Protected areas are increasingly being promoted as an important means of protecting freshwater biological diversity and ecological processes. A robust assessment of ecological changes in protected areas is fundamental to optimize conservation policies and adaptive management. China's efforts to establish aquatic reserves have attracted worldwide attention, especially the "10-year fishing ban" implemented in the Yangtze River basin.</li> <li>We focused on Liangzi Lake, a freshwater protected area in the Yangtze River basin, to understand the effect of a fishing ban occurring after a short period of overfishing. In this aim, the time series of fish community taxonomic and functional structure encompassing the overfishing period and a post-ban period have been analyzed. Fish community metrics with direct, indirect, and no responses to fishing bans were identified.</li> <li>The results indicate that in the early period of the fishing ban, the trophic level and body size structure of the fish community were in the way of recovery. However, species that prefer benthic habitats did not recover after fishing-induced habitat degradation. Functional traits were more sensitive than taxonomic indices and revealed subtle community changes, such as the recovery of some ecological functions, despite a non-recovering species richness.</li> <li> Synthesis and applications. This study provides a rare case of a freshwater protected area in which the effects of conservation measures are studied with a temporal survey. The effectiveness of the functional trait approach in the application of protected area assessment was demonstrated by revealing the recovery of trophic level and body size structure of fish communities after the implementation of the fishing ban and the inadequacy of habitat restoration efforts. We suggest that in freshwater protected areas, insistence on a fishing ban is necessary but not sufficient for full biodiversity recovery, and other measures are needed, such as habitat restoration and species-focused stocking.</li> </ol>

opencc-zeroDec 2022View details →

Data for: Direct and indirect effects of food, fear and management on crop damage by ungulates

Foraging on crops by wild ungulates may create human-wildlife conflicts through reducing crop production. Ungulates interact with and within complex socio-ecological systems, making the reduction of crop damage a challenging task. Aside from ungulate densities, crop damage is influenced by different drivers affecting ungulate foraging behavior: food availability and food quality in the landscape (i.e. the foodscape) as well as fear from hunting and scaring actions (i.e. the landscape of fear) may together affect the degree of damage via both direct and indirect effects. A better understanding of the individual effects of these potential drivers behind crop damage is needed, as is an appreciation of whether the effects are dependent on ungulate density. We investigated this by applying path analysis to test indirect and direct links between ungulate density, foodscape, landscape of fear and, human management goals on crop damage of oats and grass, respectively. Our results suggest that crop type is the major driver behind crop damage, with more damage to oats than to leys, implying that human decisions (i.e changing crop type) influence the level of crop damage. We found that management goals and actions influenced the foodscape and the landscape of fear, by affecting the amount of forage produced in the agricultural landscape and the amount of scaring actions. Additionally, we found that supplementary feeding influenced the local ungulate densities in the area. Our results highlight the importance of including human actions on multiple levels when assessing drivers behind damage by ungulates in managed landscapes. We suggest that more studies using path analysis on multiple scales are needed in order to tackle complex issues such as crop damage and other human-wildlife conflicts.

opencc-by-4.0Oct 2023View details →

Datasets for "The direct and indirect effects of the environmental factors on global terrestrial gross primary productivity over the past four decades"

The environmental changes can affect gross primary productivity (GPP) by altering not only the biogeochemical characteristics of the photosynthesis system (direct effects) but also the structure of the vegetation canopy (indirect effects). However, comprehensively quantifying the multi-pathway effects of environmental change on GPP is currently challenging. We proposed a framework to analyse the changes in global GPP by combining a nested machine-learning model and a theoretical photosynthesis model. We quantified direct and indirect effects of changes in key environmental factors (atmospheric CO2 concentration, temperature, solar radiation, vapor pressure deficit (VPD), and soil moisture) on global GPP from 1982 to 2020.  The three datasets(RF_LAI, RF_GPP, and RF_GPPlai) are derived from LAI random forest model, GPP random forest model and hierarchical nested model respectively.

The Effect of Transcranial Direct Current Stimulation on Motor Performance in Healthy Adults

ClinicalTrials.gov study NCT04577768. IPD Sharing: NO. Countries: 1. Publications: 1.

The Effectiveness of Transcranial Direct Current Stimulation (tDCS) in Decreasing Food Cravings

ClinicalTrials.gov study NCT01030289. IPD Sharing: Not stated. Countries: 1. Publications: 1.

Effect of Goal-directed Crystalloid Versus Colloid Administration on Major Postoperative Morbidity

ClinicalTrials.gov study NCT01195883. IPD Sharing: NO. Countries: 2. Publications: 1.

Combined Effect of Transcranial Direct Current Stimulation (tDCS) and Physical Activity on Gait and Functional Mobility in Participants With Multiple Sclerosis

ClinicalTrials.gov study NCT03658668. IPD Sharing: Not stated. Countries: 1. Publications: 1.

Effects of Transcranial Direct Current Stimulation (tDCS) on Language

ClinicalTrials.gov study NCT04166513. IPD Sharing: NO. Countries: 1. Publications: 40.

Effectiveness of Direct-to-Patient Outreach on Colorectal Cancer Screening Within a Low Income and Diverse Population

ClinicalTrials.gov study NCT01385579. IPD Sharing: Not stated. Countries: 1. Publications: 1.

controlledIPD-YESFeb 2026View details →

Demonstration Study of the Effect of the Transcranial Direct Current Stimulation (tDCS) on Depressed Patients

ClinicalTrials.gov study NCT05539131. IPD Sharing: YES. Countries: 1. Publications: 4.

Effects of Transcranial Direct Current Stimulation on the Apathy of Alzheimer's Disease

ClinicalTrials.gov study NCT01481558. IPD Sharing: Not stated. Countries: 1. Publications: 1.

Direct Current Cathode and Anode Effects and Changes in Handgrip Strength. Evaluation Through a Dynamometer Test

ClinicalTrials.gov study NCT02884427. IPD Sharing: NO. Countries: 1. Publications: 11.