ecosystem disruption – Page 3

Evolutionary changes in floral, vegetative, reproductive and rewarding traits, and attractiveness of Viola arvensis. We measured floral traits (a, b) in the first five developed flowers per individual (N ≈ 4000). (a) Floral area (multiplication of labellum width × corolla length). (b) Number of nectar guides. (c) Rosette diameter, measured on each plant at the start of flowering (n = 792). (d) Log-ratio of seeds produced in self-pollination compared to open pollination as a proxy of selfing ability, measured by collecting one fruit in self-pollination and one in open pollination per plant (n = 693). (e) Nectar production measured as the sum of the volume in three flowers per plants on fifty plants per population (n = 400). (f) Bumblebee preferences measured as proportion of visits per plant to a mixed plantation of 10 plants of the ancestral and 10 of the descendant populations of a single locality, exposed together to bumblebees. We recorded the number of visits to each plant by a flying bumblebee for 10 to 15 min in 6 to 8 replicates per location and divided it by the total number of visits during the flight (only visited plants are represented). The first two letters are the name of the locality (Co, Commeny; Cr, Crouy; Gu, Guernes; Lh, Lhuys). ‘A’ (triangles) ancestral population (collected in 2000 for Co, 1993 for Cr, 2001 for Gu and 1992 for Lh) and ‘D’ (circles) descendant population (all collected in 2021). Graphic: Samson Acoca-Pidolle, et al., 2023 / New Phytologist

December 26, 2023

Flowers “giving up” on scarce insects and evolving to self-pollinate, say scientists – “Our results show that the ancient interactions linking pansies to their pollinators are disappearing fast”

By Phoebe Weston 19 December 202 (The Guardian) – Flowers are “giving up on” pollinators and evolving to be less attractive to them as insect numbers decline, researchers have said. A study has found the flowers of field pansies growing near Paris are 10% smaller and produce 20% less nectar than flowers growing in the same fields […]

The Norwegian Aker BioMarine’s Antarctic Sea trawls for krill in the Southern Ocean off the coast of the South Orkney Islands, north of the Antarctic Peninsula, on 10 March 2023. Photo: AP Photo / David Keyton

October 29, 2023

Factory fishing in Antarctica for krill targets the cornerstone of a fragile ecosystem – “What’s coming out of the side are the remnants of the ecosystem”

By Joshua Goodman and David Keyton 13 October 2023 (AP) – The Antarctic Endeavour glides across the water’s silky surface as dozens of fin whales spray rainbows from their blowholes into a fairy tale icescape of massive glaciers. But as a patrol of environmentalists approaches the Chilean super trawler in an inflatable boat, the cruder […]

Geographical pattern of the primary drivers of deteriorating status among amphibians. a,b, The primary drivers of deteriorating status among amphibians during 1980–2004 (482 species; a) and 2004–2022 (306 species; b). Cell colour was determined by the primary driver impacting the most species. Where two primary drivers equally contribute to a cell, an intermediate colour is shown. The stars indicate where the primary driver is undetermined or there are numerous primary drivers. The cell area is 7,775 km2. Graphic: Luedtke, et al., 2023 / Nature

October 29, 2023

Climate change emerges as major driver of amphibian declines, new research finds – “It’s a gut punch and an awakening”

By JoAnn Adkins 4 October 2023 (FIU) – Amphibians are in trouble and in desperate need of conservation action, according to a new global assessment of the world’s amphibian population. Salamanders are experiencing the greatest decline in numbers, but frogs, toads, newts, and salamanders throughout the Neotropics — extending from South Florida and Caribbean islands […]

Number of generic extinctions per century among in different classes of vertebrates. The low number of reptiles and amphibia, which underestimate the magnitude of extinction pattern, is probably the result of the lack of information in earlier centuries, where very few species had been described. The dotted line represents the background extinction rate. Graphic: Ceballos and Ehrlich, 2023 / PNAS

September 30, 2023

Study finds human-driven mass extinction is eliminating entire branches of the tree of life – “We’re losing our only known living companions in the entire universe”

By Sean Cummings 18 September 2023 (Stanford News) – The passenger pigeon. The Tasmanian tiger. The Baiji, or Yangtze River dolphin. These rank among the best-known recent victims of what many scientists have declared the sixth mass extinction, as human actions are wiping out vertebrate animal species hundreds of times faster than they would otherwise […]

Wind farms in Boqueirão da Onça, or Jaguars’ Ravine, in the Caatinga in northeastern Brazil. Conservationists say companies shouldn’t install turbines in long rows, which forces animals to make unnecessarily long detours. Photo: Dado Galdieri / The Wall Street Journal

September 30, 2023

Brazil’s big cats under threat from wind farms – “Wind power is a fantastic proposal, and the northeast certainly has plenty of wind … but wind parks must also take into account what is happening here on the ground”

By Luciana Magalhaes and Samantha Pearson 17 September 2023 JUAZEIRO, Brazil – Weighing more than 100 pounds, big cats have long reigned over this hot and semi-arid region of Brazil, developing tougher paws for the scorched earth and reaching speeds of 50 miles an hour to bring down wild boar and deer. But nothing could […]

The Bald Mountain Wildfire burns in the Grande Prairie Forest Area in Alberta on 12 May 2023. Government of Alberta Fire Service / Canadian Press / AP

September 10, 2023

Forests are no longer our climate friends – “As extreme as this year’s wildfire emissions have been, they are just the latest escalation in a multi-decade flood of CO₂ pouring out of Canada’s ‘managed’ forests and forestry”

By David Wallace-Wells 6 September 2023 (The New York Times) – Canadian wildfires have this year burned a land area larger than 104 of the world’s 195 countries. The carbon dioxide released by them so far is estimated to be nearly 1.5 billion tons — more than twice as much as Canada releases through transportation, […]

Satellite view of an algae bloom in the waters north of the Scandinavian and Kola peninsulas, 3 August 2023. The image was acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite. One group of researchers observed large shifts in the location of summer coccolithophore blooms to the northeast between 2002 and 2018. They also identified an increasing presence of Phaeocystis pouchetii, a type of phytoplankton normally found in warmer waters that can form gelatinous colonies millimeters in diameter. The effect that such changes might have on the ecosystem is a topic of ongoing research. Data: MODIS data from NASA EOSDIS LANCE and GIBS/Worldview. Photo: Michala Garrison / NASA Earth Observatory

August 5, 2023

The ocean’s color is changing as a consequence of global warming – Color changes reflect significant shifts in essential marine ecosystems – “To actually see it happening for real is not surprising, but frightening”

By Jennifer Chu 12 July 2023 (MIT News Office) – The ocean’s color has changed significantly over the last 20 years, and the global trend is likely a consequence of human-induced climate change, report scientists at MIT, the National Oceanography Center in the U.K., and elsewhere. In a study appearing today in Nature, the team writes […]

Changes of sea surface temperature (SST) gradient anomalies and the spatial distribution of SST to a changing CO2 pathway. (A) Time evolution of latitudinal gradient of sea surface temperature anomaly (unit: °C) in the SH (pink) from its PD value. (B) Same as (A) but for the NH (black), the North Pacific (NP; 120°E to 90°W, green dotted line), and the North Atlantic (NA; 70°W to 0°E, orange dashed line) sectors with the Atlantic meridional overturning circulation (AMOC) strength anomaly from its PD value (skyblue; unit: Sv). The SST gradient is determined by the SST differences from the tropics (0° to 15°) to the midlatitudes (45° to 60°) in each hemisphere. The AMOC strength is defined by averaging annual-mean Atlantic meridional ocean stream function within the latitudinal band from 35°N to 45°N at a depth of 1000 m. Note that the weakening of AMOC is upwards in the right axis in (B). All values are based on the ensemble mean of 28 members (subjected to an 11-year running mean), with their 1 SD ranges across the ensemble members marked with shading. (C to E) SST changes (unit: °C) for peak (2121–2160) minus early RU (2001–2040) periods, late RD (2241–2280) minus peak periods, and late RD minus early RU periods, respectively. Climatological SST in the PD climate (unit: °C) is contoured in (C) to (E). The hatched regions in (C) to (E) indicate where temperature changes are statistically insignificant at the 95% confidence level. The SH, NP, and NA sectors for the SST gradient in (A) and (B) are denoted by colored boxes in (C) to (E). Graphic: Kim, et al., 2023 / Science Advances

August 5, 2023

Removing carbon from Earth’s atmosphere may not “fix” climate change – Changes to atmospheric circulation caused by global warming may persist for centuries after CO2 concentrations decrease – “We cannot control nature. We cannot reverse the consequences that easily. We cannot fix nature.”

By Tereza Pultarova 28 July 2023 (Space.com) – Removing carbon from Earth’s atmosphere may not reverse devastating changes to weather patterns in vulnerable areas, a new study suggests. In the study, Korean researchers simulated how removing large quantities of the greenhouse gas carbon dioxide from the air might affect the progress of local climate changes […]

This photo provided by the University of Miami Coral Reef Futures Lab, shows bleaching to elkhorn coral on Thursday, 20 July 2023, in the North Dry Rocks Reef off the coast of Key Largo, Fla. Some Florida Keys corals are losing their color weeks earlier in the summer than has been documented before, meaning they are under stress and their health is potentially endangered, federal scientists said. Photo: Liv Williamson / University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Science / AP

July 31, 2023

Florida’s record hot ocean temperatures cause early coral bleaching – Some reefs in the Florida Keys have already lost all their color – “We are at least a month ahead of time, if not two months”

By Cecelia Smith-Schoenwalder 26 July 2023 (US News & World Report) – Record high ocean temperatures around the Florida Keys are driving coral reefs to lose their color weeks earlier than usual in the latest sign that climate change and El Niño are pushing the world into uncharted territory. On Monday, a buoy in the […]

Correlation of significant shifts in or appearances of markers between sites documenting the onset of the Anthropocene. Collectively, the 12 reference sites, via analysis across many sites using similar multiple proxies, show the extent to which the proxies at each site cluster at an approximately coincident level around the mid-20th century, consistent with the Great Acceleration Event Array (GAEA) proposed by Waters et al. (2022). This demonstrates the degree to which the primary marker chosen at a site represents the range of critical changes encompassed by that section. Each site team has identified a level where significant changes cluster, these ranging in age between 1945 and 1968 CE, though for most sites the level chosen dates to the 1950s. Graphic: Waters, et al., 2023 / The Anthropocene Review

July 23, 2023

Canadian lake sediments reveal start of Earth’s Anthropocene epoch – “Clearly, the biology of the planet has changed abruptly. We cannot go back to a Holocene state now.”

By David Stanway 11 July 2023 (Reuters) – Sediment deposited at Crawford Lake, a small but deep body of water in Canada’s Ontario province, provides unmistakable evidence that Earth entered a new human-driven geological chapter – the Anthropocene epoch – some seven decades ago, a team of scientists said on Tuesday. The members of the […]

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Category: ecosystem disruption