38 research outputs found
Conserving All the Pollinators: Variation in Probability of Pollen Transport among Insect Taxa
As concern about declining pollinator populations mounts, it is important to understand the range of insect taxa that provide pollination services. We use pollen transport information acquired over three years in two habitats at Badlands National Park, South Dakota, USA, to compare probabilities of pollen transport among insect taxa and between sexes of bees. Sampling was conducted on 1-ha plots, eight in sparse vegetation (May–October samples; N = 74 surveys) and 12 in wheatgrass prairie vegetation (June–July samples; N = 87 surveys). Insects contacting reproductive parts of flowers were netted, placed individually into tubes charged with ethyl acetate, then transferred to individual labeled glassine envelopes for transport to the lab. Pollen was removed from insect bodies with fuchsin jelly cubes which were then mounted on microscope slides for identification. The probability of taxa transporting only conspecific pollen (with respect to the plant species upon which it was collected), mixed pollen, only non-conspecific, or no pollen was estimated with multinomial logistic regression. Bees were the most commonly captured flower visitor and carried by far the most pollen (females \u3e10× as much as males), but they were most likely to carry mixed pollen loads. Flies, beetles, and wasps were also common flower visitors and beetles were most likely to carry only conspecific pollen. Ants and diurnal lepidopterans were unlikely to carry any pollen. Bees, beetles, flies, and wasps varied in the timing and habitat in which they were most likely to transport pollen, suggesting that all played a role in providing robust pollination services
Lessons on Marine Protected Area Management in Northern Boreal Regions from the United States and Norway
In comparison to tropical reef systems, relatively few marine protected areas (MPA’s) exist in temperate or subarctic systems (e.g., North Pacific and North Atlantic) where species diversity is lower, abundance of individual species is often higher, and many fish species exhibit large amounts of movement during one or more of their life stages, especially as adults. A review of MPA’s in three northern areas—the Northwest Atlantic, Northeast Atlantic, and the Northeast Pacific—indicates that MPA’s can be useful management tools towards fisheries management and habitat conservation. However, achieving fishery goals, such as sustainable use of the fisheries resources, will depend on population abundance (relative to unfished conditions) and fish behavior and movement. For example, depleted populations of stationary species such as Atlantic sea scallops, Placopecten magellanicus, in the Northeast Atlantic and European lobster, Homarus grammarus, in the North Sea have responded positively to small MPA’s, whereas migratory offshore Atlantic cod, Gadus morhua, and Pacific cod, Gadus macrocephalus, apparently do not appear to benefit from closed areas because of movement into fished areas. Efficient habitat conservation requires detailed habitat mapping on relevant spatial scales. In northern boreal systems with large remote areas, this information is difficult and expensive to access. An alternative strategy of closing and protecting unexploited areas has worked well for the Aleutian Island coral closure area in Alaska. MPA’s can be effective fisheries management tools when the species to be protected have been depleted and show a small to moderate level of movement, and reproductive success is ensured. MPA’s can be effective at preserving habitat when the design is based on scientific information and takes into account the impact on the user groups.publishedVersio
Quantifying and addressing the prevalence and bias of study designs in the environmental and social sciences
Building trust in science and evidence-based decision-making depends heavily on the credibility of studies and their findings. Researchers employ many different study designs that vary in their risk of bias to evaluate the true effect of interventions or impacts. Here, we empirically quantify, on a large scale, the prevalence of different study designs and the magnitude of bias in their estimates. Randomised designs and controlled observational designs with pre-intervention sampling were used by just 23% of intervention studies in biodiversity conservation, and 36% of intervention studies in social science. We demonstrate, through pairwise within-study comparisons across 49 environmental datasets, that these types of designs usually give less biased estimates than simpler observational designs. We propose a model-based approach to combine study estimates that may suffer from different levels of study design bias, discuss the implications for evidence synthesis, and how to facilitate the use of more credible study designs.Fil: Christie, Alec P.. University of Cambridge; Reino UnidoFil: Abecasis, David. Universidad de Algarve. Centro de Ciencias del Mar; PortugalFil: Adjeroud, Mehdi. Université de Perpignan; Francia. Institut de Recherche Pour Le Developpement; FranciaFil: Alonso, Juan Carlos. Consejo Superior de Investigaciones Científicas. Museo Nacional de Ciencias Naturales; EspañaFil: Amano, Tatsuya. University of Queensland; AustraliaFil: Anton, Alvaro. Universidad del País Vasco. Facultad de Educación de Bilbao; EspañaFil: Baldigo, Barry P.. United States Geological Survey; Estados UnidosFil: Barrientos, Rafael. Universidad Complutense de Madrid; EspañaFil: Bicknell, Jake E.. University of Kent; Reino UnidoFil: Buhl, Deborah A.. United States Geological Survey; Estados UnidosFil: Cebrian, Just. Mississippi State University; Estados UnidosFil: Ceia, Ricardo S.. Universidad de Coimbra; PortugalFil: Cibils Martina, Luciana. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Ciencias Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Clarke, Sarah. Marine Institute; IrlandaFil: Claudet, Joachim. Universite de Paris; Francia. Centre National de la Recherche Scientifique; FranciaFil: Craig, Michael D.. University of Western Australia; Australia. Murdoch University; AustraliaFil: Davoult, Dominique. Sorbonne University; FranciaFil: De Backer, Annelies. Flanders Research Institute for Agriculture, Fisheries and Food; BélgicaFil: Donovan, Mary K.. University of California; Estados Unidos. University of Hawaii at Manoa; Estados UnidosFil: Eddy, Tyler D.. University of South Carolina; Estados Unidos. Memorial University of Newfoundland; Canadá. Victoria University of Wellington; Nueva ZelandaFil: França, Filipe M.. Lancaster University; Reino UnidoFil: Gardner, Jonathan P. A.. Victoria University of Wellington; Nueva ZelandaFil: Harris, Bradley P.. Alaska Pacific University; Estados UnidosFil: Huusko, Ari. Natural Resources Institute Finland; FinlandiaFil: Jones, Ian L.. Memorial University of Newfoundland; CanadáFil: Kelaher, Brendan P.. Southern Cross University; AustraliaFil: Kotiaho, Janne S.. Universidad de Jyvaskyla; FinlandiaFil: López Baucells, Adrià. Universidad de Lisboa; Portugal. Smithsonian Tropical Research Institute; Panamá. Universidad Nacional de Colombia. Instituto de Investigaciones Amazonicas; Colombia. Museo de Ciencias Naturales de Granollers; EspañaFil: Major, Heather L.. University of New Brunswick; CanadáFil: Mäki Petäys, Aki. Voimalohi Oy; Finlandia. University of Oulu; Finlandi
Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19
Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe
Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies
There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity
Quantifying and addressing the prevalence and bias of study designs in the environmental and social sciences
Abstract: Building trust in science and evidence-based decision-making depends heavily on the credibility of studies and their findings. Researchers employ many different study designs that vary in their risk of bias to evaluate the true effect of interventions or impacts. Here, we empirically quantify, on a large scale, the prevalence of different study designs and the magnitude of bias in their estimates. Randomised designs and controlled observational designs with pre-intervention sampling were used by just 23% of intervention studies in biodiversity conservation, and 36% of intervention studies in social science. We demonstrate, through pairwise within-study comparisons across 49 environmental datasets, that these types of designs usually give less biased estimates than simpler observational designs. We propose a model-based approach to combine study estimates that may suffer from different levels of study design bias, discuss the implications for evidence synthesis, and how to facilitate the use of more credible study designs
Responses ofNesting Sandhill Cranes to Research Activities and Effects on Nest Survival
We examined the response of nesting greater sandhill cranes (Grus canadensis tabida) to research-related activities at Grays Lake, Idaho, during 1997–2000. Data were collected on \u3e500 crane nests from 53 fields that were exposed to variable levels of research activity, from fields subjected to only periodic searches for and monitoring of crane nests (crane-only fields) to fields subjected to periodic searches for and monitoring of all waterbird nests as well as breeding bird surveys, nocturnal amphibian surveys, and other research-related activities (multi-use fields). For each nest, we calculated the visit rate to the field during the period the nest was known to be active (hereafter field visit rate) as the number of observer visits to a field while the nest was known to be active divided by the number of exposure days of the nest. The median field visit rate for all years was 0.188 visits/day, which would equate to 5.6 visits over the course of a 30-day incubation period. Length of field visits for most activities averaged 93–155 min. Of known responses, most (83.7%) cranes were flushed, but actual frequency of flushing (considering unknown responses as not flushed) was likely ~30%. Frequency of flushing for known responses was highest during nest searches (89.4%) and nest checks (87.9%) and lower during bird surveys (68.1%) and other activities (54.3%). Half of cranes that were observed to flush did so when the investigator was between 20 and 80 m away (25 and 75% quartiles, respectively; median = 32.5 m). Median flushing distances tended to be greatest for nests located in very short vegetation, but the response differed between cranes nesting in multiuse fields and cranes nesting in crane-only fields. We found no relationship between flushing distance and number of field visits. We examined the effects of field visit rate and year on nest survival using logistic-exposure approach and Akaike’s Information Criterion to evaluate support for 3 models. The model including field and year was most supported by the data; we found no support for field visit rate as an important variable explaining nest success
Factors Associated with Duck Use of Impounded and Natural Wetlands in Western South Dakota
Many wetlands in the northern Great Plains west of the Missouri River are stock ponds, created by impoundment of natural drainages or excavation of existing wetlands to provide water for livestock or improve habitat for waterfowl. We evaluated factors influencing use of wetlands by breeding duck pairs and broods relative to modification, water regime, size, and hydrological location on United States Forest Service lands within the Grand River National Grassland in northern South Dakota (2003 and 2004). Responses for both indicated pairs and broods were related positively to wet area, total wetland area within 4 km, emergent edge cover, and shoreline development index, and related negatively to basin cover (proportion of basin area with emergent cover). Duck responses were higher for instream than for isolated wetlands. Wetland type (water regime and modification) was a critical factor related to number of indicated pairs and probability of mallard (Anas platyrhyncos) use in late May. The negative response of indicated pairs to basin cover in May is associated with the high use of modified semipermanent wetlands, where wetland morphology and water depths limit emergent cover to the perimeter. Emergent edge cover was a critical factor for indicated pairs in May and for probability of use by broods in early July. The influence of wetland size and proximity to other wetlands was evident in five of eight models for pairs and all three brood models. The complexity of and variability among our models demonstrated the seasonal complexities of wetland conditions and waterfowl life history and habitat needs
Factors Influencing Soil Invertebrate Communities in Riparian Grasslands of the Central Platte River Floodplain
In the Platte River Valley of central Nebraska, USA, riparian grasslands (also known as wet meadows) have been severely impacted by a reduction in river flows, causing lower ground-water levels and altered seasonal hydroperiods. The potential impacts of these hydrologic changes, as well as the environmental factors that influence wet meadow soil invertebrate communities, are not well understood. An understanding of the ecological processes that influence these invertebrate communities is crucial for maintaining and restoring wet meadows along the Platte River. Our objectives were to describe the soil invertebrate community of wet meadows throughout the growing season and to examine the relative roles of abiotic factors in determining patterns in invertebrate community structure. We conducted the study in 12 wet meadows along the Platte River during 1999 and 2000. We identified 73 invertebrate taxa; 39 were considered soil inhabitants. Total biomass was primarily composed of earthworms, Scarabaeidae, Isopoda, and Elateridae, with earthworms and Scarabaeidae accounting for \u3e82%. Differences in river flow and precipitation patterns influenced some soil invertebrates. Earthworms and Scarabaeidae declined dramatically from 1999 (wet year) to 2000 (dry year). The topographic gradient created by the ridge-swale complex affected several soil invertebrate taxa; Scarabaeidae, Diplopoda, and Lepidoptera biomasses were greatest on drier ridges, while Tipulidae and Isopoda biomasses were greatest in wetter sloughs. Responses of earthworm taxa to the topographic gradient were variable, but generally, greater biomasses occurred on ridges and mid-elevations. Water-table depth and soil moisture were the most important variables influencing wet meadow soil invertebrates. Because these communities are linked to the hydrologic processes of the Platte River, future alterations of wet meadow hydrology could shift the distribution patterns of many of these invertebrates and possibly eliminate more moisture-tolerant taxa. To maintain wet meadows and their biotic communities, flow management should focus on regaining as much as possible of the former hydrograph through properly timed flows that provide an adequate hydrologic regime for wet meadows. In addition, restoration of wet meadows will depend on restoring the natural topography of wet meadows
Fat Dynamics of Arctic-Nesting Sandpipers During Spring in Mid-Continental North America
We measured fresh body mass, total body fat, and fat-free dry mass (FFDM) of three species of Arctic-nesting calidrid sandpipers (Baird’s Sandpiper [Calidris bairdii], hereafter “BASA”; Semipalmated Sandpiper [C. pusilla], hereafter “SESA”; and White-rumped Sandpiper [C. fuscicollis], hereafter “WRSA”) during spring stopovers in the Prairie Pothole Region (PPR) of North Dakota, and evaluated the contribution of stored fat to (1) energy requirements for migration to their Arctic-breeding grounds and (2) nutrient needs for reproduction. All spring migrant WRSA (n = 124) and BASA (n = 111), and all but 2 of 99 SESA we collected were ≥2 years old. Male and female BASA migrated through North Dakota concurrently, male SESA averaged earlier than females, and WRSA males preceded females. Fat indices (ratio of fat to FFDM) of male and female SESA and WRSA averaged approximately twice those of male and female BASA. Total body fat of male and female BASA increased with date in spring 1980, but not in 1981; slopes were similar for both sexes each year. Male and female SESA arrived lean in 1980 and 1981, and total body fat increased with date in both years, with similar slopes for all combinations of sex and year. Male and female WRSA arrived lean in 1980–1981 and 1981, respectively, and total body fat increased with date, whereas females arrived with fat reserves already acquired in 1980. Interspecific and sex differences in migration schedules probably contributed to variation in fat storage patterns by affecting maintenance energy costs and food availability. Estimated flight ranges of BASA suggest that few could have met their energy needs for migration to the breeding grounds exclusively from fat stored by the time of departure from North Dakota. Estimated flight ranges of SESA and WRSA, along with fresh body masses of both species when live-trapped on or near their breeding grounds in northern Canada, suggest that major parts of both populations stored adequate fat by departure from temperate mid-continental North America to meet their energy requirements for migration and part of their nutrient needs for reproduction