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Citizen Science Conservation Soil and Fertilizer

The Dirt on Soil

Continuing our soil theme from yesterday, today’s post focuses on pollutants in soil.

Map of the study area and watersheds near village Kibber in the high-altitude region of Spiti, Trans-Himalaya, northern India. The colored polygons represent eight watersheds spread over c. 40 km2. The native and livestock watersheds are demarcated by high ridges, escarpments and ravines, that establish replicates of two types of herbivore-assemblages (dominated by either livestock or by native herbivores). Credit: (2022). DOI: 10.1101/2022.02.07.479355

Antibiotic-laced dung ‘harming soil quality’

Antibiotics used on livestock can impact microbes in the soil and negatively affect soil carbon, reducing resilience to climate change, claims a study conducted in India’s trans-Himalayan region. Results of the study, published in Global Change Biology, found native herbivores such as yak, bharal (blue sheep), kiang (wild ass) and ibex in the Spiti valley, in India’s Himalayan state of Himachal Pradesh, to be healthier for soil carbon than livestock, which includes cattle, goat, sheep and horse. “Microbial carbon use efficiency was 19% lower in soils under livestock,” said Sumanta Bagchi, an author of the study and assistant professor at the Center for Ecological Sciences of the Indian Institute of Science in Bangalore.

Supporting evidence in the study pointed to a link between veterinary antibiotics and soil microbial decline. “Our study suggests that conserving native herbivores together with better management of livestock can go a long way towards improved soil carbon stewardship to achieve natural climate change solutions,” says Bagchi. “Our paper focused on climate impacts linked to the use of antibiotics for livestock rearing but there are other undesirable consequences such as the accelerated evolution of antibiotic resistance which is a global trend,” they added.

Home ‘compostable’ plastic doesn’t fully break down

Compostable plastic that has not fully disintegrated in compost bin. Credit: Citizen scientist image from bigcompostexperiment.org.uk.

In a UK-wide study, researchers have found that 60% of home-compostable plastics do not fully disintegrate in home compost bins, and inevitably end up in our soil. The study also found that citizens are confused about the labels of compostable and biodegradable plastics, leading to incorrect plastic waste disposal. These results highlight the need to revise and redesign this supposedly sustainable plastic waste management system.

A new OECD report shows that plastic consumption has quadrupled over the past 30 years. Globally, only 9% of plastic waste is recycled, while 50% ends up in landfills, 22% evades waste management systems, and 19% is incinerated. Compostable plastics are becoming more common as the demand for sustainable products grows. The main applications of compostable plastics include food packaging, bags; cups and plates, cutlery, and bio-waste bags. But there are some fundamental problems with these types of plastics. They are largely unregulated, and claims around their environmental benefits are often exaggerated.

In a study published in Frontiers in Sustainability, researchers at University College London have found that consumers are often confused about the meaning of the labels of compostable plastics, and that a large portion of compostable plastics do not fully disintegrate under home composting conditions.

Soil pollution in natural areas similar to urban green spaces

Microplastic debris. Credit: Roberto Ruiz (UA)

An international study, recently published in Nature Communications, shows that soil in urban green spaces and natural areas share similar levels of multiple contaminants such as metals, pesticides, microplastics and antibiotic resistance genes around the world. Soil contamination is one of the main threats to the health and sustainability of ecosystems. The work was carried out by more than 40 authors from research centers and universities in Spain, China, Switzerland, Australia, Germany, Chile, South Africa, Nigeria, France, Portugal, Slovenia, Mexico, the United States, Brazil, India and Israel. The team has collaborated with ecologist Carlos Sanz Lázaro and Nuria Casado Coy, researchers at the Ramón Margalef Multidisciplinary Institute for Environmental Studies (IMEM), and experts in the study of plastic and bioplastic pollution.

As the article reports, soil pollution is currently associated with vehicle emissions, industrial processes, pesticide treatment and plant diseases, as well as poor waste management. It is therefore to be expected that urban green spaces are more influenced by pollutants than natural ecosystems, which are geographically distant from human activities. However, the study has shown that hazardous pollutants (metals, pesticides, microplastics and antibiotic resistance genes) can be dispersed by air transport, uncontrolled waste disposal and even rainwater running off the surface of a piece of land and into natural ecosystems.

Microplastics, typical pollutants of anthropogenic (human) origin, are also ubiquitous in soils of urban green spaces and natural ecosystems around the world. Surprisingly, as reported by Sanz Lázaro, they have found similar proportions of the form and polymer type of microplastics in natural areas and urban green spaces, which further supports the idea of a spread of anthropogenic pollutants through ecosystems. These microplastics, often originating from cities, affect distant areas by atmospheric transport, with fibers being the main form of plastic particles suspended in the atmosphere in cities such as Paris, London and Dongguan (China). The fibers generally consist of polyester and polypropylene from synthetic fabrics, ropes, and nets.

(See also: From cities to uninhabited areas: Soil pollution is everywhere)

Categories
Biodiversity Climate Change Conservation Gardening Pollinators, Molluscs and Other Invertebrates Sustainable Living

2023 February Conservation Update

In this post, a fascinating DNA sampling technique; conflicting news about human impact on animal populations; and a cute story about newt rescues in California. We also look at how rising temperatures due to climate change may damage animals; and a study that shows protected areas aren’t designed to protect invertebrates. It turns out we’ve been putting those anti-bird-strike decals on the wrong side of the window; and we look at where your plants come from.

Postcard-sized poo sample collection cards offer an affordable alternative to more cumbersome methods of collecting and storing the genetic information in dung. The cards do not need to be refrigerated and maintain viable DNA for months after collection. Credit: Fred Zwicky

Streamlined DNA for wildlife conservation

A team from University of Illinois at Urbana-Champaign has come up with a new way of sampling DNA that allows scientists to capture genetic information from wildlife without disturbing the animals or putting their own safety in jeopardy. The protocol, tested on elephant dung, yielded enough DNA to sequence whole genomes not only of the elephants but also of the associated microbes, plants, parasites and other organisms—at a fraction of the cost of current approaches. The researchers report their findings in the journal Frontiers in Genetics.

A family of urban raccoons. Photo by Jon Last.

Can urban neighborhoods be both dense and green?

The British Ecological Society reports on a new study from The Nature Conservancy (TNC) that explores how we can make our cities work better for people and wildlife.  By analyzing existing approaches, as well as highlighting cities already creating the right balance of people and wildlife, the study pioneers an alternative method of city design that allows for the accommodation of both denser populations as well as wildlife. “This needn’t be a zero-sum game,” explains senior author and TNC lead scientist for nature-based solutions, Rob Mcdonald. “Having denser cities doesn’t automatically mean less space for nature.”

But, while animals may be able to co-exist happily with humans in urban areas, another study highlights how human incursions into natural areas can disturb wildlife.

Researchers placed camera traps along hiking trails in Glacier National Park during and after a COVID-19 closure. They found that 16 out of 22 mammal species changed the way they accessed areas when humans were present. Credit: Mammal Spatial Ecology and Conservation Lab, Washington State University

Human recreation changes wildlife behavior

Even without hunting rifles, humans appear to have a strong negative influence on the movement of wildlife. A study of Glacier National Park hiking trails during and after a COVID-19 closure adds evidence to the theory that humans can create a “landscape of fear” like other apex predators, changing how species use an area simply with their presence. Researchers found that when human hikers were present, 16 out of 22 mammal species, including predators and prey alike, changed where and when they accessed areas. Some completely abandoned places they previously used, others used them less frequently, and some shifted to more nocturnal activities to avoid humans. The study was published in the journal Scientific Reports. The researchers had also expected to find an effect known as “human shielding,” when human presence causes large predators to avoid an area, providing opportunity for smaller predators and perhaps some prey species to use an area more frequently. In this case, they found this potential effect for only one species, red fox. The foxes were more present on and near trails when the park was open–perhaps because their competitors, coyotes, avoided those areas when humans were around. While the influence of low-impact recreation is concerning, the researchers emphasized that more research is needed to determine if it has negative effects on the species’ survival.

Credit: Unsplash/CC0 Public Domain

Animals at risk from heat waves

More than 40% of all land vertebrates may be subjected to extreme heat events by 2099 under current maximum estimates of future global temperatures, according to a study published in Nature. Prolonged exposure to high temperatures could be dangerous for the future of many species across the globe. Extreme thermal events, a period in which the temperature greatly exceeds a historical threshold, have increased in frequency compared to historical records, exacerbated by climate change caused by human activity. Recurring periods of extreme heat affect wildlife and are associated with increased psychological stress, reduced reproductive output and decreased population sizes, meaning that the continuation of these temperature spikes would pose a substantial threat to future biodiversity.

A ‘Big Night’ for Newts

The New York Times has a heart-warming story about the heroic work of the northern California Chileno Valley Newt Brigade in rescuing amphibians that might otherwise become roadkill as they cross a road from their breeding grounds and their burrows. But newt rescue is just a short-term solution. The group is also fundraising for road modifications that will allow the newts to pass safely underneath.

Black swallowtail on thistle at New Life Retreat. Photo by Carol English.

Protected areas fail insect species

Insects play crucial roles in almost every ecosystem—they pollinate more than 80% of plants and are a major source of food for thousands of vertebrate species—but insect populations are collapsing around the globe, and they continue to be overlooked by conservation efforts. Protected areas can safeguard threatened species but only if these threatened species actually live within the areas we protect. A new study in the journal One Earth found that 76% of insect species are not adequately covered by protected areas.

Northern cardinal. Photo by Jon Last.

What we know about bird window strikes is inside-out

New research from William & Mary published in PeerJ reveals that decals intended to reduce incidents of bird window strikes—one of the largest human-made causes of bird mortality—are only effective if decals are placed on the outside of the window. Researchers found that the patterns on the films and decals placed on the internal surface of windows do not reduce collision because they may not be sufficiently visible to birds.

A fynbos bouquet from South Africa. Credit: Juan Pablo Moreiras/Fauna & Flora

Where do your plants come from?

Tim Knight of Fauna and Flora International asks if we ever ask ourselves where all our garden plants come from? The local garden center or superstore isn’t the answer. Take bulbs, for instance. There’s a common understanding that most bulbs come from The Netherlands. In fact, most wild tulips hail from the mountainous regions of Central Asia. Kyrgyzstan, Tajikistan, Kazakhstan and Uzbekistan—countries not widely recognized as havens of biodiversity—harbor the lion’s share of species. Turkey is also one of the richest areas in the world for bulbs, including familiar garden favorites such as snowdrops, crocuses, cyclamens and, yes, tulips too. It’s easy to forget that these wild relatives are the original source of the endless varieties and hybrid forms that grace our gardens and fill our flower vases. And that they face a variety of threats, from overharvesting and habitat loss to climate change.

Houseplants come from all over, including the popular Monstera, which is an epiphyte, growing on trees in its native South America. With one notable exception, bromeliads are found only in Central and South America. A single species—endangered and known only from Guinea—occurs in West Africa. Most bromeliads are also epiphytes, but the one that we’re most familiar with—though you may not think of it as a bromeliad—grows on the ground and produces one of our most popular tropical fruits, the pineapple.

White Christmas cactus. Photo by R. Last.

Cacti may be famous for their tolerance of extreme heat and drought—and plummeting temperatures at night—but they’re not confined to hotspots like the American Midwest and Mexico. Of the roughly 2,500 species of cactus in the world, quite a few thrive in rainforests or cooler climes. The Christmas cactus is native to damp forest in the coastal mountains of Brazil.

The article goes on to detail the origins of orchids (pretty much from every continent, except Antarctica); where cut flowers come from; and what makes the fynbos in South Africa so special. Mr. Knight concludes by urging gardeners to pay attention to the origins of plants they purchase and avoid those that come from unsustainable sources.

Categories
Crime

Crime is lower when cities are greener

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NOVEMBER 10, 2022
Crime is lower when cities are greener: Evidence from South Africa supports the link
by Charlie Shackleton, Andrew Faull, Gregory Breetzke, Ian Edelstein and Zander Venter, The Conversation
south african cityCape Town, South Africa. Credit: Unsplash/CC0 Public Domain

Crime is lower when cities are greener: Evidence from South Africa supports the link: South Africa’s population is urbanizing at a rapid pace. The sheer rate of change poses challenges to planning for sustainable and liveable cities. Part of what make cities work is having green spaces, such as parks, sports fields, nature trails and street trees. These provide many social, ecological and economic benefits. Research from multiple countries such as Australia, China, Finland, India, the U.S. and South Africa has shown this. Aside from looking good and providing recreation, urban green spaces improve air quality, physical and mental health, and regulate storm water flows. They counteract urban heat islands, store carbon and create jobs. Some communities nevertheless oppose urban greening efforts because they fear that green spaces and street trees provide places for criminals to hide. Such fears are not unique to South Africa and have been reported from cities in both developed and developing countries. We conducted research to complement the evidence from the global north. Our study is the first ever national level analysis of the relationship between various measures of urban greenness and three different classes of crime: property, violent and sexual crimes. Our findings, based on research in South Africa, lend further credence to calls for urban greening to be adopted as a major strategy in cities—for both environmental sustainability, as well as social sustainability. We found that greener areas had lower rates of both violent and property crimes. But there was no relationship with the rate of sexual crimes. A more mixed picture was revealed when considering tree cover specifically, where property crime was higher with more tree cover, but violent crimes were fewer.