| 1. |
- Bansal, Sheel, et al.
(författare)
-
Practical Guide to Measuring Wetland Carbon Pools and Fluxes
- 2023
-
Ingår i: Wetlands (Wilmington, N.C.). - : SPRINGER. - 0277-5212 .- 1943-6246. ; 43:8
-
Forskningsöversikt (refereegranskat)abstract
- Wetlands cover a small portion of the world, but have disproportionate influence on global carbon (C) sequestration, carbon dioxide and methane emissions, and aquatic C fluxes. However, the underlying biogeochemical processes that affect wetland C pools and fluxes are complex and dynamic, making measurements of wetland C challenging. Over decades of research, many observational, experimental, and analytical approaches have been developed to understand and quantify pools and fluxes of wetland C. Sampling approaches range in their representation of wetland C from short to long timeframes and local to landscape spatial scales. This review summarizes common and cutting-edge methodological approaches for quantifying wetland C pools and fluxes. We first define each of the major C pools and fluxes and provide rationale for their importance to wetland C dynamics. For each approach, we clarify what component of wetland C is measured and its spatial and temporal representativeness and constraints. We describe practical considerations for each approach, such as where and when an approach is typically used, who can conduct the measurements (expertise, training requirements), and how approaches are conducted, including considerations on equipment complexity and costs. Finally, we review key covariates and ancillary measurements that enhance the interpretation of findings and facilitate model development. The protocols that we describe to measure soil, water, vegetation, and gases are also relevant for related disciplines such as ecology. Improved quality and consistency of data collection and reporting across studies will help reduce global uncertainties and develop management strategies to use wetlands as nature-based climate solutions.
|
|
| 2. |
- Hudson, Lawrence N., et al.
(författare)
-
The PREDICTS database : a global database of how local terrestrial biodiversity responds to human impacts
- 2014
-
Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 4:24, s. 4701-4735
-
Tidskriftsartikel (refereegranskat)abstract
- Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species' threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project - and avert - future declines. We describe and assess a new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains more than 1% of the total number of all species described, and more than 1% of the described species within many taxonomic groups - including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans. The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses. The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems - ). We make site-level summary data available alongside this article. The full database will be publicly available in 2015.
|
|
| 3. |
- Sigmund, G., et al.
(författare)
-
Addressing chemical pollution in biodiversity research
- 2023
-
Ingår i: Global Change Biology. - : Wiley. - 1354-1013 .- 1365-2486. ; 29:12, s. 3240-3255
-
Tidskriftsartikel (refereegranskat)abstract
- Climate change, biodiversity loss, and chemical pollution are planetary-scale emergencies requiring urgent mitigation actions. As these "triple crises" are deeply interlinked, they need to be tackled in an integrative manner. However, while climate change and biodiversity are often studied together, chemical pollution as a global change factor contributing to worldwide biodiversity loss has received much less attention in biodiversity research so far. Here, we review evidence showing that the multifaceted effects of anthropogenic chemicals in the environment are posing a growing threat to biodiversity and ecosystems. Therefore, failure to account for pollution effects may significantly undermine the success of biodiversity protection efforts. We argue that progress in understanding and counteracting the negative impact of chemical pollution on biodiversity requires collective efforts of scientists from different disciplines, including but not limited to ecology, ecotoxicology, and environmental chemistry. Importantly, recent developments in these fields have now enabled comprehensive studies that could efficiently address the manifold interactions between chemicals and ecosystems. Based on their experience with intricate studies of biodiversity, ecologists are well equipped to embrace the additional challenge of chemical complexity through interdisciplinary collaborations. This offers a unique opportunity to jointly advance a seminal frontier in pollution ecology and facilitate the development of innovative solutions for environmental protection.
|
|
| 4. |
- Potapov, Anton M., et al.
(författare)
-
Globally invariant metabolism but density-diversity mismatch in springtails
- 2023
-
Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 14:1
-
Tidskriftsartikel (refereegranskat)abstract
- Soil life supports the functioning and biodiversity of terrestrial ecosystems. Springtails (Collembola) are among the most abundant soil arthropods regulating soil fertility and flow of energy through above- and belowground food webs. However, the global distribution of springtail diversity and density, and how these relate to energy fluxes remains unknown. Here, using a global dataset representing 2470 sites, we estimate the total soil springtail biomass at 27.5 megatons carbon, which is threefold higher than wild terrestrial vertebrates, and record peak densities up to 2 million individuals per square meter in the tundra. Despite a 20-fold biomass difference between the tundra and the tropics, springtail energy use (community metabolism) remains similar across the latitudinal gradient, owing to the changes in temperature with latitude. Neither springtail density nor community metabolism is predicted by local species richness, which is high in the tropics, but comparably high in some temperate forests and even tundra. Changes in springtail activity may emerge from latitudinal gradients in temperature, predation and resource limitation in soil communities. Contrasting relationships of biomass, diversity and activity of springtail communities with temperature suggest that climate warming will alter fundamental soil biodiversity metrics in different directions, potentially restructuring terrestrial food webs and affecting soil functioning.
|
|
| 5. |
- Nyokabi, Ndungu S., et al.
(författare)
-
Exploring the composition and structure of milk and meat value chains, food safety risks and governance in the Addis Ababa and Oromia regions of Ethiopia
- 2023
-
Ingår i: Frontiers in Sustainable Food Systems. - : Frontiers Media S.A.. - 2571-581X. ; 7
-
Tidskriftsartikel (refereegranskat)abstract
- Demand for animal-source foods (ASF) is increasing globally, driven by population growth and changing dietary preferences. In global south countries, low compliance with good agricultural practices (GAPs) and food safety standards in the production of ASF is a major public health concern due to the high prevalence of foodborne diseases. This study examines the composition and structure of milk and meat value chains and explores food safety risks and governance in the Addis Ababa and Oromia regions of Ethiopia. Stakeholder discussions, key informant interviews and participant observation were undertaken to collect data on milk and meat value chain actors' perceptions of opportunities and constraints to improving access to safe, high-quality milk and meat products. The results reveal low compliance with rules and standards by milk and meat value chain actors which could compromise food safety and quality and expose consumers to public health risks. There was stricter enforcement of GAPs and food safety standards in the case of milk and meat products destined for export compared to products sold in the local market. The main barriers to compliance with food safety regulations were actors' low knowledge, small profit margins, absence of critical food safety infrastructure such as electricity and road and low access to capital to invest in the recommended equipment such as aluminum containers, coolers and fridges. This paper concludes there is a need for targeted efforts to support the adoption of low-cost technologies that could mitigate food safety risks. Additionally, there is a need for improved communication and tailored training for value chain actors that reflect local social, cultural and economic context to incentivise compliance with rules governing food safety and quality.
|
|
| 6. |
- Berg, Christina, 1963, et al.
(författare)
-
Relation between breakfast food choices and knowledge of dietary fat and fiber among Swedish schoolchildren.
- 2002
-
Ingår i: The Journal of adolescent health : official publication of the Society for Adolescent Medicine. - 1054-139X. ; 31:2, s. 199-207
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To investigate dietary knowledge and beliefs of schoolchildren, in relationship to breakfast choices, with specific attention to fat and fiber content. METHODS: Food choice and perceptions were studied by interviews using the "stacking box methodology". Youth (n = 181) aged 11-15 years were instructed to select food items among photographs of breakfast foods. In addition to choosing their own typical breakfasts, they were asked to exchange foods in hypothetical breakfasts to create meals with less fat and more fiber. The interview also dealt with recent changes in breakfast habits, and perceptions of healthy breakfasts, dietary fat, and foods rich in fiber. Data were analyzed by logistic regression. RESULTS: Knowledge concerning sources and health attributes of dietary fiber was associated with usual consumption of bread and breakfast cereals rich in fiber. In a similar way, a positive attitude toward limited fat intake predicted consumption of reduced-fat milk products. However, no association was observed between food choices and knowledge of a food-packaging symbol indicating low-fat and fiber-enriched foods. CONCLUSION: Lack of awareness of, and knowledge about, healthy eating may be important barriers to the development of health promoting food habits by schoolchildren.
|
|
| 7. |
- Berg, Christina, 1963, et al.
(författare)
-
Sources of bias in a dietary survey of children.
- 1998
-
Ingår i: European journal of clinical nutrition. - 0954-3007. ; 52:9, s. 663-7
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To compare non-responders and responders to a dietary survey with respect to demographic variables and intention to choose selected breakfast foods, and to examine if there was any systematic change in number of food items reported during a 7 d recording period. DESIGN: Cross-sectional survey. SETTING: Mölndal, Sweden. SUBJECTS: All pupils in 5th, 7th and 9th grades in the municipality were asked to complete a questionnaire during school hours. All those present (n = 1584, 92% of total) answered questions about lifestyle factors and about intentions, attitudes and beliefs concerning high-fibre bread and milk with varying fat content. All subjects in the initial sample were asked to fill in a 7 d record of food consumed. Acceptable food records were completed by 69% of the initial participants. RESULTS: Subjects not completing the food record differed significantly from participants with respect to demographic, lifestyle and dietary factors. Dropout was more common among those who reported not usually eating breakfast and among those intending to drink whole milk for breakfast. A decline in reported food items during the recording period was also observed. CONCLUSIONS: Two sources of bias were observed here, one indicating significant differences between non-participants and participants, the other suggesting the presence of a time-dependent trend in number of recorded foods. It is likely such biases are present in other dietary surveys involving schoolchildren, and should be taken into consideration in the design, analysis and interpretation of such studies.
|
|
| 8. |
- Kovacikova, Janka, et al.
(författare)
-
Computational and experimental analysis of timber beams with different types of flaws
- 2020
-
Ingår i: Fracture and damage mechanics. - : American Institute of Physics (AIP).
-
Konferensbidrag (refereegranskat)abstract
- This work was focused on the experimental testing and finite element analysis (FEA) of timber beams with and without flaws (different types of cracks and hole). The aim was analysing the effect of flaws on their load-carrying capacity. This topic is important for designers of timber constructions, since even today there is still a lack of knowledge in the field of fracture mechanics of wood. The results from experimental testing and numerical simulations were discussed in this paper. Two wood products were analysed, namely, sawn and glued laminated beams (glulam beams) and three types of flaws were considered for both products i.e. a vertical crack, an oblique crack and a circular hole. In addition for glulam beams the horizontal crack in the glue line was considered. Four-point bending test was created for experimental testing considering quasi-brittle characteristic of wood. 4 samples for each type of beam, 36 in total. XFEM (Extended Finite Element Method) was used for finite element analysis of beams with considering orthotropic-elastic properties for glulam beams were considered and The results of mechanical tests and FEA gave us an overview on how different types of flaws influence the load-carrying capacity of sawn and glulam beams and with what accuracy we can simulate cracks in wood using computational method.
|
|
| 9. |
- Limpens, J., et al.
(författare)
-
Climatic modifiers of the response to nitrogen deposition in peat-forming Sphagnum mosses : a meta-analysis
- 2011
-
Ingår i: New Phytologist. - : Wiley. - 0028-646X .- 1469-8137. ; 191:2, s. 496-507
-
Tidskriftsartikel (refereegranskat)abstract
- Peatlands in the northern hemisphere have accumulated more atmospheric carbon (C) during the Holocene than any other terrestrial ecosystem, making peatlands long-term C sinks of global importance. Projected increases in nitrogen (N) deposition and temperature make future accumulation rates uncertain. Here, we assessed the impact of N deposition on peatland C sequestration potential by investigating the effects of experimental N addition on Sphagnum moss. We employed meta-regressions to the results of 107 field experiments, accounting for sampling dependence in the data. We found that high N loading (comprising N application rate, experiment duration, background N deposition) depressed Sphagnum production relative to untreated controls. The interactive effects of presence of competitive vascular plants and high tissue N concentrations indicated intensified biotic interactions and altered nutrient stochiometry as mechanisms underlying the detrimental N effects. Importantly, a higher summer temperature (mean for July) and increased annual precipitation intensified the negative effects of N. The temperature effect was comparable to an experimental application of almost 4 g N m(-2) yr(-1) for each 1 degrees C increase. Our results indicate that current rates of N deposition in a warmer environment will strongly inhibit C sequestration by Sphagnum-dominated vegetation.
|
|
| 10. |
- Toreti, A, et al.
(författare)
-
Narrowing uncertainties in the effects of elevated CO2 on crops
- 2020
-
Ingår i: Nature Food. - : Springer Science and Business Media LLC. - 2662-1355. ; 1, s. 775-782
-
Tidskriftsartikel (refereegranskat)abstract
- Plant responses to rising atmospheric carbon dioxide (CO2) concentrations, together with projected variations in temperature and precipitation will determine future agricultural production. Estimates of the impacts of climate change on agriculture provide essential information to design effective adaptation strategies, and develop sustainable food systems. Here, we review the current experimental evidence and crop models on the effects of elevated CO2 concentrations. Recent concerted efforts have narrowed the uncertainties in CO2-induced crop responses so that climate change impact simulations omitting CO2 can now be eliminated. To address remaining knowledge gaps and uncertainties in estimating the effects of elevated CO2 and climate change on crops, future research should expand experiments on more crop species under a wider range of growing conditions, improve the representation of responses to climate extremes in crop models, and simulate additional crop physiological processes related to nutritional quality.
|
|
