Opinion: Chicago may have been the birthplace of the modern skyscraper, but the city is now more interested in landscape projects that make New York's High Line look like small fry, says Jonathan D Solomon, director of architecture at the School of the Art Institute of Chicago.

In his 1970 essay Chicago a la Carte: the City as Energy System, the great architect and educator Alvin Boyarsky described the city as "a catalogue of audacious engineering feats, determined by everything that was not there to begin with".

Revelling in the multi-layer organisation of the Loop – Chicago's central business district – Boyarsky saw beauty in the scale of speed and flow its infrastructure was built to accommodate.

In fact, Chicago owes its very existence to engineered solutions and manipulation of the landscape. William Cronan, in his 1991 history Nature's Metropolis: Chicago and the Great West, tells the history of Chicago's role in the formation of the American West through its great feats: reversing rivers, building rails, rising from the mud and the fire, harnessing commodities and credit. The city that Carl Sandberg called "Hog butcher, tool maker, stacker of wheat, player with railroads and freight handler to the nation."

At the same time, Chicago is a living laboratory of future infrastructure. Industrial-scale systems defined the American city in the 20th century. But in the 21st it has become a city about innovation in landscape design – a field that has reinvented itself at the cutting edge of experimental practice both in public space and urbanism.

Chicago in 2015 is a study in the city as (expanded) landscape. Great projects are still reshaping public space, but smaller interventions based less on concrete and steel and more on human networks are having as important an effect, not only to space but to the economy, politics and culture.

The city is still a hub of rail and air travel, but it is also home to a sprawling, publicly operated and privately sponsored bike share network, Divvy. It is still the centre of the commodities trade, but it is also a hub of contemporary maker-culture, such as Charles Adler's Center for Lost Arts. It is still the birthplace of the skyscraper, but it is also the home of innovative preservation projects such as Theaster Gates and Rebuild Foundation's Stony Island Arts Bank.

Chicago has always been a city of big plans, even if they take a long time to come together. In 1871 the city suffered a great tragedy when Chicago burned in a massive fire. Eager to rebuild, the city pushed debris into a shallow lagoon between Michigan Avenue and the Illinois Central Railway along the shore of Lake Michigan, creating land that would become Grant Park, the city's "front yard". It became home to some of the city's great institutions, such as the Art Institute of Chicago, the Field Museum, and Soldier Field.

The north-west corner of the park was still an exposed rail cut and parking lot until 1997, when the city began work on 24.4 acres of terraced decks, public art, fountains, and gardens called Millennium Park. Opening in 2004, the park's $475 million (£130 million) cost was carried by the city and private donors. Once empty on nights and weekends, the surrounding area is now home to Chicago's tallest residential towers and commands some of the city's highest rents.

While The High Line garnered international attention in New York, Chicago was quietly constructing a linear park on an elevated rail viaduct more than twice the High Line's length. Designed by the New York firm Michael Van Valkenburgh Associates, the 606 (named for the first three digits of city's zip codes) joins diverse neighbourhoods on the city's West Side with widely disparate demographics and median incomes. Lead artist on the project Frances Whitehead collaborated with Chicago Wilderness and the USA National Phenologic Network, resulting in a line of 453 native, flowering trees – the temperature-sensitive Apple Serviceberry – to capture the warming effect of Lake Michigan as spring blooms spread along the line over five days. The project helps bring together populations that might not ordinarily share space.

Chicago's river and lakefronts have seen improvements as well. In 2012, mayor Rahm Emmanuel unveiled plans for the Chicago Riverwalk. Under construction in the Loop, the Riverwalk will provide spectacular views from under the city's famous trunnion bascule bridges.

Northerly Island, an artificial peninsula envisaged in Daniel Burnham and Edward Bennett's 1909 Plan of Chicago, was reclaimed from Lake Michigan in the 1920s and served as the site for the 1933 World's Fair, A Century of Progress. It later became an airport, Miegs Field. In 1994 then-mayor Richard M Daley proposed to turn it into a public park. The State Legislature objected, arguing that the field (convenient for their short flights between Chicago and Springfield, the State Capitol) was good for business. On the night of Sunday 30 March 2003, Mayor Daley sent city bulldozers to cut a series of Xs in the runways, ending the discussion.

This year, Northerly Island Park designed by Studio Gang Architects opened to the public. A rolling 40-acre landscape of lush dunes and lagoons, it is a remarkable remove from the city. An integrated component of the city's Museum Campus, a major tourist destination, it is also vindication of Daley's hard-handed politics.

These new, large projects are complemented by the growing impact of expanded landscape on Chicago's culture. As new generations of artists and designers redefine the relationship of the city to nature, they are also expanding the city's access to public space and resources.

The natural has always had a complex relationship to the built in Chicago. Petra Bachmaier and Sean Gallero, who make up the light and media artist duo Luftwerk, explore the contemporary relationship between nature and technology in a series of installations recently completed at the Garfield Park Conservatory. Built in 1907, the 4.5-acre conservatory was designed with the famed landscape architect Jens Jensen. It collects plants from tropical ferns and palms to desert succulents. Solarize: A Sea of all Colors includes an LED installation on the inside of the conservatory's glass and iron shell that simulates grass waving in the wind, and a series of other site-specific projects that use colour, sound and reflection to situate nature in the city. Solar-powered and off-grid, the project is supported by the local utility ComEd.

Expanded landscape operates between large- and small-scale networks to find solutions with local impacts. At O'Hare airport, the Chicago Department of Aviation has, since 2013, relied on a herd of goats, sheep, llamas and burros to maintain the grounds. The herd has reduced reliance on pesticides, heavy equipment, and fuels; lowering costs and improving the airport's carbon footprint. O'Hare is also home to the first major on-airport apiary in the US, with 75 hives and over a million bees. In an example of how individuals are creating new networks and expanding access to resources, Bike-a-Bee, started as a Kickstarter project by Jana Kinsman, provides beehives to community gardens by bicycle throughout the city. The organisation also teaches in primary schools and summer camps about the ecological value of bees.

Throughout its history Chicago has repeatedly demonstrated that blight can be made productive. Sweetwater Foundation addresses ecological and social blight by showing how communities can turn waste into resources through collaborative engagements in education and urban agriculture. The Chicago-based non-profit operates urban farms and aquaponics hubs that repurpose abandoned buildings and lots to offer workshops and internship opportunities to local public school students. Educated as an architect, co-founder Emmanuel Pratt is now Chair of Aquaponics at Chicago State University. He describes his hyper-local partnerships and network of community resources as "chaortic" — a mashup of chaos and order.

For visitors to the Chicago Architecture Biennial who expressed a desire to see the spirit of experimentation in the exhibitions better reflected in the city's recent construction boom, the city's recent engagement with the "energy systems" of landscape architecture should provide some satisfaction. Landscape in Chicago is moving into architecture's once totalising embrace of infrastructure; and is radically expanding the purview and potential of design. Chicago – the city as (expanded) landscape, the city of experimental practice – is where new scales of infrastructure and new social networks are engendering new spaces, economies, and new communities for the 21st-century city, is again and always the city of the future.

Jonathan D Solomon is director of Architecture, Interior Architecture and Designed Objects at the School of the Art Institute of Chicago, and editor of the art and design journal Forty-Five. Solomon edited the influential series 306090 Books for over a decade and served as curator of the US Pavilion at the 2010 Venice Architecture Biennale. His latest book, Cities Without Ground, is published by Oro Editions.