What kind of wildlife flourishes in cities?

The High Line in New York City, a former elevated railroad trestle converted to a public park. Image: Shinya Suzuki/Flickr/creative commons.

Biodiversity refers to the variety of all living things on Earth, but people often have very specific ideas of what it means. If you run an online search for images of biodiversity, you are likely to find lots of photos of tropical rainforests and coral reefs.

Those ecosystems are invaluable, but biodiversity also exists in many other places. More than half of the people on Earth live in cities, and that number is growing, so it is especially important to understand how biodiversity patterns occur in our man-made environments.

As an ecologist specializing in urban systems, I spend a lot of time investigating biodiversity in parks, residential areas and abandoned zones in and around the city of Baltimore. My main interests are seeing how urban dwellers invest in biodiversity, which species persist in cities and what kinds of biodiversity can thrive in green spaces.

In spite of the substantial environmental changes that humans have caused in cities, research shows that they still contain many forms of life. And we can develop and maintain habitat to support them.

Human impacts

Human activities such as farming and building roads disturb the environment. This changes habitats, causes plants and animals to move and alters biodiversity patterns.

In cities many of these shifts are obvious. Cats and coyotes are now the top predators in many urban areas, perhaps replacing species that dominated before these areas were settled. Humans have introduced exotic species such as tree of heaven, and pests such as the emerald ash borer. And our living patterns have promoted eruptive growth of some species, such as white-tailed deer.

Razing a vacant row home in Baltimore, Maryland. This kind of activity creates habitat. Image: author provided.

It is common to assume that few other species remain in disturbed urban environments. But in fact, there are many pockets of biodiversity in and around cities, such as frogs living in stormwater detention ponds and trees in restored streamside forests. Landscapes that people create in and around their homes support many ornamental herbaceous and woody plant species.

Our research group works to understand the relationship between people and urban biodiversity patterns. The most prominent feature of the urban environment is that it is fragmented into many small zones. Human activity creates more patches of smaller size and greater edge lengths between types of habitats than we would expect to see in undisturbed areas.

This benefits species that thrive at edges, like white-tailed deer and nuisance vines, but harms others that require larger interior habitats, such as certain birds. As human activities create a more fragmented environment, it becomes increasingly important to create linkages between natural areas, such as preserved forests, to maintain populations and their biodiversity.

Humans also modify dispersal patterns. We place preferred plants in our yards and gardens, transplant wild shrubs from forests to suburban yards and trap nuisance animals such as beavers and relocate them to forests.

Two vacant lots where row homes once stood in Baltimore, Maryland. Each plot was cleared and seeded with native species. Even after one year on these poor soils, native plants established. Image: author provided.

Work from our research group has successfully related people’s management practices to understand how species are gained or lost from one location to the next. This concept, which we call “species turnover,” is a major way in which biodiversity increases in cities. Where people make many different types of choices, we have found that the trees people manage change a lot. This tells us that what one person sees as valuable differs from the views of another, which increase biodiversity in these areas. In “ignored” or less managed areas, such as vacant land, we see a less diverse mix of species on average.


How past actions influence the present

Ecologists can also understand biodiversity in cities by studying how humans have altered and then abandoned some areas, and how plants and animals have responded. Such human legacies are profound in old cities like Baltimore.

Our research group has studied these impacts on patches of land where buildings once stood. There are more than 14,000 vacant lots in Baltimore where houses have been razed, which adds up to a lot of habitat.

We have found that buildings’ footprints have very different soils from the areas around them that once were backyards. Footprint soils are compact and comprise mainly building rubble, while backyards have healthier soils. Although these habitats are close together, they support different plant communities. Plants growing on building footprints tend to be similar, while there is very high species turnover in former back yards.

Helping urban ecosystems thrive

Every species has traits, such as a plant’s nitrogen fixation rate and flower color. These characteristics support the services that the species can offer – for example, providing habitat for songbirds. As cities move toward more green practices, knowing about species’ traits can help planners choose which plants, animals, birds and insects to support.

In West Baltimore, my research group has cleared and seeded vacant lots with different mixes of native plants that reflect different traits to learn which species combinations can confer the most ecosystem services. In urban areas, valuable ecosystem services include supporting bees and other pollinators and improving soil quality.

We have found that native plant species can become established and persist even on poor urban soils. Working with local high school students, we have carried out pollinator surveys over two years, which show that these plants support more abundant and more diverse communities of pollinators, including bumblebees and butterflies. Over the next five to 10 years, we plan to expand this work across 65 plots on vacant land so that we can understand the full range of ecosystem services that native plants provide.

7x7 meter experimental plots where 15 abandoned row houses once stood. These plots are being seeded with different mixes of native plants. Image: author provided.

Residents who live near our research plots are happy to see areas that were unmanaged and largely neglected turn green. Even small “pocket parks” can brighten communities.

The ConversationWe have many other questions about urban biodiversity. How do city dwellers living in cities think about biodiversity? What traits of different animals and plants do people find attractive, and do those traits provide desirable ecosystem services? By analysing these issues, we can learn more about which animals and plants do the most to enhance city life and how we can help them thrive here.

Christopher Swan is professor of geography and environmental systems at University of Maryland, Baltimore County.

This article was originally published on The Conversation. Read the original article.

 
 
 
 

A new wave of remote workers could bring lasting change to pricey rental markets

There’s a wide world of speculation about the long-lasting changes to real estate caused by the coronavirus. (Valery Hache/AFP via Getty Images)

When the coronavirus spread around the world this spring, government-issued stay-at-home orders essentially forced a global social experiment on remote work.

Perhaps not surprisingly, people who are able to work from home generally like doing so. A recent survey from iOmetrics and Global Workplace Analytics on the work-from-home experience found that 68% of the 2,865 responses said they were “very successful working from home”, 76% want to continue working from home at least one day a week, and 16% don’t want to return to the office at all.

It’s not just employees who’ve gained this appreciation for remote work – several companies are acknowledging benefits from it as well. On 11 June, the workplace chat company Slack joined the growing number of companies that will allow employees to work from home even after the pandemic. “Most employees will have the option to work remotely on a permanent basis if they choose,” Slack said in a public statement, “and we will begin to increasingly hire employees who are permanently remote.”

This type of declaration has been echoing through workspaces since Twitter made its announcement on 12 May, particularly in the tech sector. Since then, companies including Coinbase, Square, Shopify, and Upwork have taken the same steps.


Remote work is much more accessible to white and higher-wage workers in tech, finance, and business services sectors, according to the Economic Policy Institute, and the concentration of these jobs in some major cities has contributed to ballooning housing costs in those markets. Much of the workforce that can work remotely is also more able to afford moving than those on lower incomes working in the hospitality or retail sectors. If they choose not to report back to HQ in San Francisco or New York City, for example, that could potentially have an effect on the white-hot rental and real estate markets in those and other cities.

Data from Zumper, an online apartment rental platform, suggests that some of the priciest rental markets in the US have already started to soften. In June, rent prices for San Francisco’s one- and two-bedroom apartments dropped more than 9% compared to one year before, according to the company’s monthly rent report. The figures were similar in nearby Silicon Valley hotspots of San Jose, Mountain View, Palo Alto.

Six of the 10 highest-rent cities in the US posted year-over-year declines, including New York City, Los Angeles, and Seattle. At the same time, rents increased in some cheaper cities that aren’t far from expensive ones: “In our top markets, while Boston and San Francisco rents were on the decline, Providence and Sacramento prices were both up around 5% last month,” Zumper reports.

In San Francisco, some property owners have begun offering a month or more of free rent to attract new tenants, KQED reports, and an April survey from the San Francisco Apartment Association showed 16% of rental housing providers had residents break a lease or unexpectedly give a 30-day notice to vacate.

It’s still too early to say how much of this movement can be attributed to remote work, layoffs or pay cuts, but some who see this time as an opportunity to move are taking it.

Jay Streets, who owns a two-unit house in San Francisco, says he recently had tenants give notice and move to Kentucky this spring.

“He worked for Google, she worked for another tech company,” Streets says. “When Covid happened, they were on vacation in Palm Springs and they didn’t come back.”

The couple kept the lease on their $4,500 two-bedroom apartment until Google announced its employees would be working from home for the rest of the year, at which point they officially moved out. “They couldn’t justify paying rent on an apartment they didn’t need,” Streets says.

When he re-listed the apartment in May for the same price, the requests poured in. “Overwhelmingly, everyone that came to look at it were all in the situation where they were now working from home,” he says. “They were all in one-bedrooms and they all wanted an extra bedroom because they were all working from home.”

In early June, Yessika Patapoff and her husband moved from San Francisco’s Lower Haight neighbourhood to Tiburon, a charming town north of the city. Patapoff is an attorney who’s been unemployed since before Covid-19 hit, and her husband is working from home. She says her husband’s employer has been flexible about working from home, but it is not currently a permanent situation. While they’re paying a similar price for housing, they now have more space, and no plans to move back.

“My husband and I were already growing tired of the city before Covid,” Patapoff says.

Similar stories emerged in the UK, where real estate markets almost completely stopped for 50 days during lockdown, causing a rush of demand when it reopened. “Enquiry activity has been extraordinary,” Damian Gray, head of Knight Frank’s Oxford office told World Property Journal. “I've never been contacted by so many people that want to live outside London."

Several estate agencies in London have reported a rush for properties since the market opened back up, particularly for more spacious properties with outdoor space. However, Mansion Global noted this is likely due to pent up demand from 50 days of almost complete real estate shutdown, so it’s hard to tell whether that trend will continue.

There’s a wide world of speculation about the long-lasting changes to real estate caused by the coronavirus, but many industry experts say there will indeed be change.

In May, The New York Times reported that three of New York City’s largest commercial tenants — Barclays, JP Morgan Chase and Morgan Stanley — have hinted that many of their employees likely won’t be returning to the office at the level they were pre-Covid.

Until workers are able to safely return to offices, it’s impossible to tell exactly how much office space will stay vacant post-pandemic. On one hand, businesses could require more space to account for physical distancing; on the other hand, they could embrace remote working permanently, or find some middle ground that brings fewer people into the office on a daily basis.

“It’s tough to say anything to the office market because most people are not back working in their office yet,” says Robert Knakal, chairman of JLL Capital Markets. “There will be changes in the office market and there will likely be changes in the residential market as well in terms of how buildings are maintained, constructed, [and] designed.”

Those who do return to the office may find a reversal of recent design trends that favoured open, airy layouts with desks clustered tightly together. “The space per employee likely to go up would counterbalance the folks who are no longer coming into the office,” Knakal says.

There has been some discussion of using newly vacant office space for residential needs, and while that’s appealing to housing advocates in cities that sorely need more housing, Bill Rudin, CEO of Rudin Management Company, recently told Spectrum News that the conversion process may be too difficult to be practical.

"I don’t know the amount of buildings out there that could be adapted," he said. "It’s very complicated and expensive.

While there’s been tumult in San Francisco’s rental scene, housing developers appear to still be moving forward with their plans, says Dan Sider, director of executive programs at the SF Planning Department.

“Despite the doom and gloom that we all read about daily, our office continues to see interest from the development community – particularly larger, more established developers – in both moving ahead with existing applications and in submitting new applications for large projects,” he says.

How demand for those projects might change and what it might do to improve affordable housing is still unknown, though “demand will recover,” Sider predicts.

Johanna Flashman is a freelance writer based in Oakland, California.