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Categories: Environmental: Ecosystems, Mathematics: General
Published Forests recovering from logging act as a source of carbon
(via sciencedaily.com) Original source Tropical forests recovering from logging are sources of carbon for years afterwards, contrary to previous assumptions, finds a new study.
Published Indigenous territories and protected areas are key to forest conservation in the Brazilian Amazon, study shows
(via sciencedaily.com) A U.S.-Brazilian study using time series satellite images from 2000 to 2021 reveals the vital role of Indigenous territories and protected areas for forest conservation in the Brazilian Amazon, as well as calls attention to the negative impacts of weakened governmental conservation policies in recent years.
Published Study details impact of prairie dog plague die-off on other species
(via sciencedaily.com) This study, conducted from 2015-19 in the Thunder Basin National Grassland, may be the first to specifically examine the multispecies impacts of a wide-scale plague outbreak, which reduced the area covered by prairie dog colonies from nearly 25,000 acres to only about 125 acres in the study area. The 2017 outbreak was followed by abnormally high precipitation in 2018, which caused vegetation to grow quickly and taller without the presence of prairie dogs. The researchers found that the mountain plover, birds that thrive when vegetation is kept shorter by prairie dogs, almost disappeared from the study area, while migrant songbirds such as the lark bunting, which prefer taller vegetation, increased in number. Meanwhile, species including ferruginous hawks, badgers and swift foxes declined dramatically as their prey base crashed.
Published Fathoming the hidden heatwaves that threaten coral reefs
(via sciencedaily.com) The severity of marine heatwaves (MHWs) that are increasingly impacting ocean ecosystems, including vulnerable coral reefs, has primarily been assessed using remotely sensed sea-surface temperatures (SSTs), without information relevant to heating across ecosystem depths. Here, using a rare combination of SST, high-resolution in-situ temperatures, and sea level anomalies observed over 15 years near Moorea, French Polynesia, we document subsurface MHWs that have been paradoxical in comparison to SST metrics and associated with unexpected coral bleaching across depths. Variations in the depth range and severity of MHWs was driven by mesoscale (10s to 100s of km) eddies that altered sea levels and thermocline depths and decreased (2007, 2017 and 2019) or increased (2012, 2015, 2016) internal-wave cooling.
Published Invasive rats transform reef fish behavior
(via sciencedaily.com) Scientists have discovered for the first time that invasive rats on tropical islands are affecting the territorial behavior of fish on surrounding coral reefs. The new study shows that the presence of invasive black rats on tropical islands is causing changes in the territorial behavior of the jewel damselfish -- a herbivorous species of tropical reef fish that 'farm' algae in the branches of corals.
Published New York City's greenery absorbs a surprising amount of its carbon emissions
(via sciencedaily.com) Original source A study of vegetation across New York City and some densely populated adjoining areas has found that on many summer days, photosynthesis by trees and grasses absorbs all the carbon emissions produced by cars, trucks and buses, and then some. The surprising result, based on new hyper-local vegetation maps, points to the underappreciated importance of urban greenery in the carbon cycle.
Published Reef fish must relearn the 'rules of engagement' after coral bleaching
(via sciencedaily.com) Mass coral bleaching events are making it harder for some species of reef fish to identify competitors, new research reveals. Scientists studying reefs across five Indo-Pacific regions found that the ability of butterflyfish individuals to identify competitor species and respond appropriately was compromised after widespread loss of coral caused by bleaching. This change means they make poorer decisions that leave them less able to avoid unnecessary fights, using up precious limited energy.
Published Modelling the collective movement of bacteria
(via sciencedaily.com) A new paper presents a mathematical model for the motion of bacteria that includes cell division and death, the basic ingredients of the cell cycle.
Published Slime for the climate, delivered by brown algae
(via sciencedaily.com) Original source Brown algae take up large amounts of carbon dioxide from the air and release parts of the carbon contained therein back into the environment in mucous form. This mucus is hard to break down for other ocean inhabitants, thus the carbon is removed from the atmosphere for a long time, as researchers now show. They reveal that the algal mucus called fucoidan is particularly responsible for this carbon removal and estimate that brown algae could thus remove up to 550 million tons of carbon dioxide from the air every year -- almost the amount of Germany's entire annual greenhouse gas emissions.
Published Rwandan tree carbon stock mapped from above
(via sciencedaily.com) Original source Researchers have developed accurate nation-wide mapping of the carbon content of trees based on aerial images.
Published Bird diversity increased in severely burned forests of Southern Appalachian mountains
(via sciencedaily.com) A new study found bird diversity increased in North Carolina mountain forest areas severely burned by wildfire in 2016, reinforcing that while wildfire can pose risks to safety and property, it can be beneficial to wildlife. The study results could help forest managers better predict bird responses to wildfire, and manage forests to benefit birds.
Published Palau's Rock Islands harbor heat-resistant corals
(via sciencedaily.com) Original source Ocean warming is driving an increase in the frequency and severity of marine heatwaves, causing untold damage to coral reefs. Tropical corals, which live in symbiosis with tiny single celled algae, are sensitive to high temperatures, and exhibit a stress response called bleaching when the ocean gets too hot. In the last 4 decades, marine heatwaves have caused widespread bleaching, and killed millions of corals. Because of this, a global search is underway for reefs that can withstand the heat stress, survive future warming, and act as sources of heat-tolerant coral larvae to replenish affected areas both naturally and through restoration.
Published Carbon, soot and particles from combustion end up in deep-sea trenches
(via sciencedaily.com) New research shows that disproportionately large amounts of carbon accumulate at the bottom of deep-sea trenches. The trenches may thus play an important role for deep-sea storage of organic material -- and thus for the atmospheric Co2 balance.
Published Using deep learning to monitor India's disappearing forest cover
(via sciencedaily.com) Using satellite monitoring data, researchers have developed a deep learning algorithm that could provide real-time monthly land use and land cover maps for parts of India.
Published UK woodlands could store almost twice as much carbon as previously estimated
(via sciencedaily.com) Original source UK forests could store almost double the amount of carbon than previous calculations suggest, with consequences for our understanding of carbon stocks and humanity's response to climate change, according to a new study.
Published Do polar bear paws hold the secret to better tire traction?
(via sciencedaily.com) Traction is important. Humans have been continually interested in discovering how to better move across wet or frozen surfaces safely -- whether to improve shoes for walking on sidewalks or tires to maneuver the roadways. But what makes it possible for some Arctic animals to walk and run across the ice so effortlessly and gracefully without slipping and falling? Researchers took a deep dive into the paws of polar bears to find out. What the team discovered was that all bears (except sun bears) have papillae on their paw pads, but that the papillae on polar bears were taller -- up to 1.5 times. And, that the taller papillae of polar bears help to increase traction on snow relative to shorter ones. Even though polar bears have smaller paw pads compared to the other species (likely because of greater fur coverage for heat conservation), the taller papillae of polar bears compensate for their smaller paw pads, giving them a 30-50% increase in frictional shear stress.
Published New study finds logged tropical forests are surprisingly vibrant and need protection
(via sciencedaily.com) New study examines the flow of ecological energy across old-growth forests, logged forests and oil palm. The study surveys mammal and bird species across these landscapes to calculate food energetic pathways: how photosynthetic energy cascades from sunlight to be distributed among organisms. Relative to energy flow in old-growth forests, study finds 2.5 times more total energy flows in logged forests. The study findings question the use of the word 'degraded' to describe logged tropical forests.
Published Transplants can save dying coral reefs, but genetically diverse donors are key
(via sciencedaily.com) Study uses lab-grown coral clones to determine why some coral thrive when transplanted onto coral reefs and others die.
Published A peculiar protected structure links Viking knots with quantum vortices
(via sciencedaily.com) Original source Mathematical analysis identifies a vortex structure that is impervious to decay.
Published Revealing the complex magnetization reversal mechanism with topological data analysis
(via sciencedaily.com) The reliability of data storage and writing speed in advanced magnetic devices depend on drastic, complex changes in microscopic magnetic domain structures. However, it is extremely challenging to quantify these changes, limiting our understanding of magnetic phenomena. To tackle this, researchers developed, using machine learning and topology, an analysis method that quantifies the complexity of the magnetic domain structures, revealing hidden features of magnetization reversal that are hardly seen by human eyes.