Human Wealth Increases Urban Plant Diversity

Family income and housing age are key predictors of plant diversity within cities, according to a new study.

1 minute read

June 30, 2003, 5:00 AM PDT

By Chris Steins @planetizen


Variation in plant diversity has traditionally been attributed to resource availability within ecosystems. However, urbanization has resulted in plant communities created solely by humans, reflecting social, economic, and cultural influences. To explore the parameters that determine plant diversity across a large urban area, Diane Hope and colleagues surveyed the number of perennial woody species in Phoenix and the surrounding Sonoran desert. For each site, the researchers also charted data in categories such as current and historic land use, elevation, and several socioeconomic variables. In addition to traditional ecological factors, the scientists found that socioeconomic factors best explained variations in plant diversity. For example, in neighborhoods where household incomes were higher than the city's median, plant diversity was approximately twice that of less affluent areas. Also, newer housing developments had higher diversity than older ones. The scientists suggest that wealth may shape landscapes and increase limited resources, allowing a greater number of plant species to flourish.

Thanks to Adam Rogers

Tuesday, July 1, 2003 in Proceedings Of The National Academy Of Sciences

Young Professional

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban and Environmental Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban and Environmental Planner

Get top-rated, practical training for planners

"Planetizen federal action tracker" logo superimposed over black and white image of US Capitol dome.

Planetizen Federal Action Tracker

A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

September 30, 2026 - Zachary Whalen

The mayor of Baltimore speaks into a microphone in front of a rally for more state transportation funding from Maryland.

‘Going backwards:’ Baltimore mayor, students rally against state's transit funding plan

Maryland's proposed six-year plan provides no funding for Baltimore’s BMORE bus program and reduces its road maintenance funding.

October 2, 2026 - Baltimore Sun

A rendering of the waterfront development, which shows a lit-up stage by the waterfront and people walking about.

Detroit to transform waterfront with $2.2 billion investment

Developers will convert about 18 acres of unused parking lot space into civic spaces.

October 2, 2026 - ABC 7

A rendering of the courthouse. The middle section is glass, the far left and right pillars are white.

Planned $2 billion courthouse in MA sparks tension with local government

Springfield owns an essential piece of the land developers intend to build on, and some city officials do not want to see the project come to fruition.

October 5 - Boston Globe

A person installing solar panels on a wall. The panels are tilted slightly, the head of the person is hidden under one of them.

Californians can now transform balconies into power generators

Gov. Gavin Newsom has legalized plug-in solar technology, which allows residents to plug solar panels directly into their outlets

October 5 - Grist

An aerial view of the new state park, with a forest and lake visible under a sunset.

This 85-year-old ranch is Texas’ newest state park

The 650 acre ranch is one of the largest parcels of land along Lake Palestine.

October 5 - Houston Chronicle

FREE Course: Walkable City 1: Why Walkability?

After describing his path towards focusing on walkability as the essence of good planning, Jeff Speck marches through his five principal reasons for making more walkable places.

Reinventing Malls: Planning Alchemy—Turning Gray Fields Into Gold

The course focuses on the opportunities and imperatives that shape reinvention of mall sites.

Senior Planner

City of Thousand Oaks

Community Development Director

City of Wisconsin Rapids

Professor of Urban Planning

Harvard University Graduate School of Design