| 1. |
- Jarvis, Erich D., et al.
(författare)
-
Whole-genome analyses resolve early branches in the tree of life of modern birds
- 2014
-
Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 346:6215, s. 1320-1331
-
Tidskriftsartikel (refereegranskat)abstract
- To better determine the history of modern birds, we performed a genome-scale phylogenetic analysis of 48 species representing all orders of Neoaves using phylogenomic methods created to handle genome-scale data. We recovered a highly resolved tree that confirms previously controversial sister or close relationships. We identified the first divergence in Neoaves, two groups we named Passerea and Columbea, representing independent lineages of diverse and convergently evolved land and water bird species. Among Passerea, we infer the common ancestor of core landbirds to have been an apex predator and confirm independent gains of vocal learning. Among Columbea, we identify pigeons and flamingoes as belonging to sister clades. Even with whole genomes, some of the earliest branches in Neoaves proved challenging to resolve, which was best explained by massive protein-coding sequence convergence and high levels of incomplete lineage sorting that occurred during a rapid radiation after the Cretaceous-Paleogene mass extinction event about 66 million years ago.
|
|
| 2. |
- Otero, Jaime, et al.
(författare)
-
Basin-scale phenology and effects of climate variability on global timing of initial seaward migration of Atlantic salmon (Salmo salar)
- 2014
-
Ingår i: Global Change Biology. - : Wiley. - 1354-1013 .- 1365-2486. ; 20:1, s. 61-75
-
Tidskriftsartikel (refereegranskat)abstract
- Migrations between different habitats are key events in the lives of many organisms. Such movements involve annually recurring travel over long distances usually triggered by seasonal changes in the environment. Often, the migration is associated with travel to or from reproduction areas to regions of growth. Young anadromous Atlantic salmon (Salmo salar) emigrate from freshwater nursery areas during spring and early summer to feed and grow in the North Atlantic Ocean. The transition from the freshwater ('parr') stage to the migratory stage where they descend streams and enter salt water ('smolt') is characterized by morphological, physiological and behavioural changes where the timing of this parr-smolt transition is cued by photoperiod and water temperature. Environmental conditions in the freshwater habitat control the downstream migration and contribute to within- and among-river variation in migratory timing. Moreover, the timing of the freshwater emigration has likely evolved to meet environmental conditions in the ocean as these affect growth and survival of the post-smolts. Using generalized additive mixed-effects modelling, we analysed spatio-temporal variations in the dates of downstream smolt migration in 67 rivers throughout the North Atlantic during the last five decades and found that migrations were earlier in populations in the east than the west. After accounting for this spatial effect, the initiation of the downstream migration among rivers was positively associated with freshwater temperatures, up to about 10 °C and levelling off at higher values, and with sea-surface temperatures. Earlier migration occurred when river discharge levels were low but increasing. On average, the initiation of the smolt seaward migration has occurred 2.5 days earlier per decade throughout the basin of the North Atlantic. This shift in phenology matches changes in air, river, and ocean temperatures, suggesting that Atlantic salmon emigration is responding to the current global climate changes.
|
|
| 3. |
- Gamfeldt, Lars, 1975, et al.
(författare)
-
Higher levels of multiple ecosystem services are found in forests with more tree species
- 2013
-
Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 4
-
Tidskriftsartikel (refereegranskat)abstract
- Forests are of major importance to human society, contributing several crucial ecosystem services. Biodiversity is suggested to positively influence multiple services but evidence from natural systems at scales relevant to management is scarce. Here, across a scale of 400,000km2, we report that tree species richness in production forests shows positive to positively hump-shaped relationships with multiple ecosystem services. These include production of tree biomass, soil carbon storage, berry production and game production potential. For example, biomass production was approximately 50% greater with five than with one tree species. In addition, we show positive relationships between tree species richness and proxies for other biodiversity components. Importantly, no single tree species was able to promote all services, and some services were negatively correlated to each other. Management of production forests will therefore benefit from considering multiple tree species to sustain the full range of benefits that the society obtains from forests.
|
|
| 4. |
- Albrecht, Matthias, et al.
(författare)
-
The effectiveness of flower strips and hedgerows on pest control, pollination services and crop yield : a quantitative synthesis
- 2020
-
Ingår i: Ecology Letters. - : Wiley. - 1461-023X .- 1461-0248. ; 23:10, s. 1488-1498
-
Tidskriftsartikel (refereegranskat)abstract
- Floral plantings are promoted to foster ecological intensification of agriculture through provisioning of ecosystem services. However, a comprehensive assessment of the effectiveness of different floral plantings, their characteristics and consequences for crop yield is lacking. Here we quantified the impacts of flower strips and hedgerows on pest control (18 studies) and pollination services (17 studies) in adjacent crops in North America, Europe and New Zealand. Flower strips, but not hedgerows, enhanced pest control services in adjacent fields by 16% on average. However, effects on crop pollination and yield were more variable. Our synthesis identifies several important drivers of variability in effectiveness of plantings: pollination services declined exponentially with distance from plantings, and perennial and older flower strips with higher flowering plant diversity enhanced pollination more effectively. These findings provide promising pathways to optimise floral plantings to more effectively contribute to ecosystem service delivery and ecological intensification of agriculture in the future.
|
|
| 5. |
- Andersson, Erik, et al.
(författare)
-
Ambio fit for the 2020s
- 2022
-
Ingår i: Ambio. - : Springer Nature. - 0044-7447 .- 1654-7209. ; 51:5, s. 1091-1093
-
Tidskriftsartikel (refereegranskat)
|
|
| 6. |
- Bergström, Ann-Kristin, 1968-, et al.
(författare)
-
Biomass, community composition and N:P recycling ratios of zooplankton in northern high-latitude lakes with contrasting levels of N deposition and dissolved organic carbon
- 2022
-
Ingår i: Freshwater Biology. - : John Wiley & Sons. - 0046-5070 .- 1365-2427. ; 67:9, s. 1508-1520
-
Tidskriftsartikel (refereegranskat)abstract
- Global changes are causing decreases in inorganic nitrogen (N) concentrations, increases in coloured dissolved organic carbon (DOC) concentrations, and decreases in dissolved inorganic N to total phosphorus ratios (DIN:TP) in northern lakes. The effects of these changes on phytoplankton and zooplankton biomass and the N:P recycling ratio of zooplankton remain unresolved.In 33 Swedish headwater lakes across subarctic-to-boreal gradients with different levels of N deposition (low N in the north [Västerbotten, boreal; Abisko, subarctic] vs. high N in the south [Värmland, boreal; Jämtland, subarctic]), we measured water chemistry, phytoplankton biomass (chlorophyll-a [Chl-a], Chl-a:TP), seston mineral quality (C:P, N:P), as well as zooplankton biomass, community composition, and C:N:P stoichiometry. We estimated nutrient imbalances and the N:P recycling ratios of zooplankton using ecological stoichiometry models.There was a large-scale gradient from low lake DIN and DIN:TP in the north to high DIN and DIN:TP in the south, with lower DIN:TP in lakes coinciding with higher DOC within each region. Lower lake DIN was associated with lower phytoplankton biomass (lower Chl-a:TP). Lower lake DIN:TP was associated with richer seston mineral quality (lower seston C:P and N:P) and higher zooplankton biomass.Zooplankton community composition differed in the north vs. south, with a dominance of N-requiring calanoid copepods with high N:P in the north and P-requiring cladocerans with low N:P in the south. Also, greater differences in zooplankton community composition were found between subarctic regions (with lower DOC) than between boreal regions (with higher DOC), suggesting that increases in lake DOC and associated declines in lake DIN:TP reduce differences in zooplankton community composition.The combination of lower lake DIN, higher lake DOC, and lower lake DIN:TP led to reduced zooplankton N:P recycling ratios, possibly by reducing seston N:P and/or by enhancing calanoid copepod dominance in the zooplankton community.Our findings suggest that the combination of declining N deposition and increasing lake browning in northern high-latitude lakes will reduce phytoplankton biomass, but will concurrently enhance seston mineral quality and probably also zooplankton biomass and their recycling efficiency of P relative to N.
|
|
| 7. |
- Bergström, Ann-Kristin, 1968-, et al.
(författare)
-
Declining calcium concentration drives shifts toward smaller and less nutritious zooplankton in northern lakes
- 2024
-
Ingår i: Global Change Biology. - : John Wiley & Sons. - 1354-1013 .- 1365-2486. ; 30:3
-
Tidskriftsartikel (refereegranskat)abstract
- Zooplankton community composition of northern lakes is changing due to the interactive effects of climate change and recovery from acidification, yet limited data are available to assess these changes combined. Here, we built a database using archives of temperature, water chemistry and zooplankton data from 60 Scandinavian lakes that represent broad spatial and temporal gradients in key parameters: temperature, calcium (Ca), total phosphorus (TP), total organic carbon (TOC), and pH. Using machine learning techniques, we found that Ca was the most important determinant of the relative abundance of all zooplankton groups studied, while pH was second, and TOC third in importance. Further, we found that Ca is declining in almost all lakes, and we detected a critical Ca threshold in lake water of 1.3 mg L−1, below which the relative abundance of zooplankton shifts toward dominance of Holopedium gibberum and small cladocerans at the expense of Daphnia and copepods. Our findings suggest that low Ca concentrations may shape zooplankton communities, and that current trajectories of Ca decline could promote widespread changes in pelagic food webs as zooplankton are important trophic links from phytoplankton to fish and different zooplankton species play different roles in this context.
|
|
| 8. |
- Jonsson, Karin, 1982, et al.
(författare)
-
Rye and health - Where do we stand and where do we go?
- 2018
-
Ingår i: Trends in Food Science and Technology. - : Elsevier BV. - 0924-2244 .- 1879-3053. ; 79, s. 78-87
-
Forskningsöversikt (refereegranskat)abstract
- Background: High whole grain intake has consistently been associated with lowered risk of developing a number of chronic diseases. Among cereals, rye has highest content of dietary fiber, together with a wide variety of bioactive compounds. There is accumulating evidence from intervention studies of physiological effects of rye foods with potential health benefits. Scope and approach: This review summarizes the state of the art of rye and health and identifies future directions for research and innovation, based partly on findings presented at the international conference “The Power of Rye” Åland, Finland, 7–8 June 2017. Key findings and conclusions: Rye foods have well-established beneficial effects on insulin metabolism compared with wheat bread under isocaloric conditions and at standardized amounts of available carbohydrates, which may have positive implications for diabetes prevention. Recent findings suggest that alterations in blood glucose flux partly explain these effects. Moreover, several studies have shown beneficial effects of rye-based foods on satiety, which is one plausible mechanism behind recently demonstrated beneficial effects on weight management. Emerging results indicate beneficial effects of rye intake on inflammation and blood lipids. More research is needed to uncover underlying mechanisms for other demonstrated effects and the long-term implications for health. A challenge with rye-based foods is making them palatable and widely acceptable to consumers. Development of innovative and tasty rye products and targeted communication strategies is crucial in increasing awareness and consumption of rye foods. Novel results in this regard are presented in this review.
|
|
| 9. |
- Jonsson, Mattias, et al.
(författare)
-
When natural habitat fails to enhance biological pest control - Five hypotheses
- 2016
-
Ingår i: Biological Conservation. - : Elsevier BV. - 0006-3207 .- 1873-2917. ; 204, s. 449-458
-
Tidskriftsartikel (refereegranskat)abstract
- Ecologists and farmers often have contrasting perceptions about the value of natural habitat in agricultural production landscapes, which so far has been little acknowledged in ecology and conservation. Ecologists and conservationists often appreciate the contribution of natural habitat to biodiversity and potential ecosystem services such as biological pest control, whereas many farmers see habitat remnants as a waste of cropland or source of pests. While natural habitat has been shown to increase pest control in many systems, we here identify five hypotheses for when and why natural habitat can fail to support biological pest control, and illustrate each with case studies from the literature: (1) pest populations have no effective natural enemies in the region, (2) natural habitat is a greater source of pests than natural enemies, (3) crops provide more resources for natural enemies than does natural habitat, (4) natural habitat is insufficient in amount, proximity, composition, or configuration to provide large enough enemy populations needed for pest control, and (5) agricultural practices counteract enemy establishment and biocontrol provided by natural habitat. In conclusion, we show that the relative importance of natural habitat for biocontrol can vary dramatically depending on type of crop, pest, predator, land management, and landscape structure. This variation needs to be considered when designing measures aimed at enhancing biocontrol services through restoring or maintaining natural habitat . (C) 2016 Published by Elsevier Ltd.
|
|
| 10. |
- Knapp, Jessica L, et al.
(författare)
-
Ecological traits interact with landscape context to determine bees' pesticide risk
- 2023
-
Ingår i: Nature Ecology and Evolution. - : Springer Science and Business Media LLC. - 2397-334X. ; 7, s. 547-556
-
Tidskriftsartikel (refereegranskat)abstract
- Widespread contamination of ecosystems with pesticides threatens non-target organisms. However, the extent to which life-history traits affect pesticide exposure and resulting risk in different landscape contexts remains poorly understood. We address this for bees across an agricultural land-use gradient based on pesticide assays of pollen and nectar collected by Apis mellifera, Bombus terrestris and Osmia bicornis, representing extensive, intermediate and limited foraging traits. We found that extensive foragers (A. mellifera) experienced the highest pesticide risk-additive toxicity-weighted concentrations. However, only intermediate (B. terrestris) and limited foragers (O. bicornis) responded to landscape context-experiencing lower pesticide risk with less agricultural land. Pesticide risk correlated among bee species and between food sources and was greatest in A. mellifera-collected pollen-useful information for future postapproval pesticide monitoring. We provide foraging trait- and landscape-dependent information on the occurrence, concentration and identity of pesticides that bees encounter to estimate pesticide risk, which is necessary for more realistic risk assessment and essential information for tracking policy goals to reduce pesticide risk.
|
|
