Posts tagged biodiversity

These orchids in bloom smell like warm honey. (All photo: Jenni Zell)

Did you know the city of Los Angeles lies within a global biodiversity hotspot? I did not, at least until Australian landscape architect and academic Richard Weller presented his Atlas for the End of the World at USC in 2016. Weller’s presentation – combined with the call to action embedded in the books, The Invention of Nature: Alexander Von Humbolt’s New World and The Sixth Extinction an Unnatural History – challenged me to reevaluate my concept of nature. The presentation and books also helped aid my understanding of the richness of species and endemism of the place I’ve practiced landscape architecture and called home for most of my life.

Click here to see my entire 2018 Biodiversity Report (PDF).

Last month, the city of Los Angeles published their 2018 Biodiversity Report, which makes LA the first city in the United States to measure biodiversity using the Singapore Index. The report represents an important first step toward protecting and enhancing biodiversity, establishing a baseline measurement to compare change over time. The body of the report also establishes a framework for building a customized Los Angeles Index, pointing the way forward in the utilization of published academic journals about biodiversity to help develop, fund, and implement both policies and projects.

Landscape architects share responsibility for the homogenization and dramatic reduction of native biodiversity in developed areas, and in turn, play a substantial role in restoring and strengthening biodiversity in urban, suburban, and agricultural areas, both in the role of policy development and its implementation.

This convergence of conviction and new acquired knowledge inspired me to create a biodiversity report of my own home. The first step in the scientific method is observation, so what better way to gain a more complete understanding and appreciation of the value of biodiversity reports than applying it to the world immediately around me.



Awaiting these ripening figs to be gathered soon for breakfast.

Epiphyte hanging by my front door

Dyckias and cobweb hena and chicks.

Native California verbena and dudleya.

An annual poppy being visited by a honey bee.





Hill St and 5th Street (Creative Commons photo via Wikipedia)

As Los Angeles has evolved over the last 150 years, so has its ecology. Once a pristine mixture of ecotones, including chaparral, coastal sage scrub, and annual grasslands, it is now dominated by a naturalized urban forest and a blanket of concrete. Humans have introduced a variety of fantasy landscapes from faux-tropical paradises to Midwestern suburbs, and created the layered, modified landscape we are all familiar with today.

As Los Angeles has become the densest city in the United States, it has maintained its status as a biodiversity hotspot due in part to these complex microclimates and its location in the western hemisphere migration. However, development of the city has led to a critical loss of open space threatening flora and fauna diversity. Recognizing this issue, members of the Los Angeles City Council passed a motion last year to support biodiversity. City agencies have since come together to develop a biodiversity plan, starting with an index of existing ecology and leading to implementing policy and action. The index, presented at the end of April by the Bureau of Sanitation, is based on the Singapore Index.  It quantifies indicators of ecological health such as natural areas, pervious surfaces, urban forest canopy, and native birds in built areas. By evaluating these criteria, they hope to support both ecological and human health in Los Angeles.

It is necessary to understand the impacts of historical and current land use changes caused by humans. By replacing open space with buildings and infrastructure, we are removing the benefits provided by soil, water infiltration, tree canopy, and wildlife. Los Angeles’ signature sprawl, which admittedly has its own issues, has also allowed for a complex patchwork of open spaces from private yards to the sides of freeways to vacant lots. These spaces play an important role in the ecology of the city, but are being lost to urban infill.

In the course of the city’s history, green open space and tree canopy have favored the white and wealthy.  Poor and working class neighborhoods of color are still tremendously lacking in tree canopy and parks, and these ecological deserts create physical and mental health disparities. By focusing on improving biodiversity especially in these communities, habitat becomes an issue of environmental social justice. But establishing a value for biodiversity and native ecology, without monetizing these life essentials, is difficult. How can the city evolve to support population growth, a healthy ecology, and environmental equality?

This Yellow Breasted Chat was seen in Downtown LA under a large field of reflective windows, an assumed victim of the urban ecosystem. If we seek to increase bird populations in the city, we must be sensitive to how design affects them. Photo by Katherine Montgomery

While we cannot restore all species to their pre-1850 populations, we can better support those that have adapted to urban spaces, and lure back some that might be able to adapt. The presentation at the Bureau of Sanitiation last month was titled “Conserving Biodiversity when Land is Developed” and several presenters discussed the varied methods of considering how non-humans use our shared space. The presentation focused mainly on birds as indicator species for overall habitat health.  Los Angeles is the “birdiest” county in the United States, with 527 recorded species.  The birds have complex seasonal roles, using our region for wintering, breeding, as a stop-over, or a year-round home. Some require large contiguous areas of open space while some are happy in urban fragments. Scientists are currently studying bird habits and the connections between them, plant species, and insects. This important information will then guide policy as well as design of open spaces to support those complex avifauna behaviors.

The 2018 Biodiversity Report is the start of a very important conversation that landscape architects will play a huge role in. As we work on commercial, residential, and civic developments, we can advocate for design that values natural systems and their performance benefits. One of our greatest influences is in the design of schools, introducing kids to nature as early as possible. The city must also institute policies that support a diverse density and not just a capitalist drive towards development. An interdisciplinary approach, using engineering, green infrastructure, policy and cultural awareness will enable Los Angeles to thrive in a changing climate and evolve into a healthy city for humans and wildlife.

Photo: Natural History Museum, Los Angeles

Photo: Natural History Museum, Los Angeles

A little over a month ago my wife traveled down to the Natural History Museum to learn how to participate in the world’s largest urban biodiversity study. The BioSCAN ProjectRASCals (Reptiles and Amphibians of Southern California), SLIME (Snails and slugs Living in Metropolitan Environments), and the Southern California Squirrel Survey, in partnership with the Urban Nature Research Center at Los Angeles Natural History Museum, have all coordinated to invite regular people to become scientists…citizen scientists.

Photo: Gregory Han

Photo: Gregory Han

Because of the expansion of urban development, many animal species have had to adapt – or perish – affecting biodiversity in ways that aren’t always apparent. The NHM’s Citizen Science Program is turning to Angelenos to aid in investigating distribution and behavior of various species.

For example, we all see squirrels happily doing there thing here across Los Angeles. On the surface the population seems to be thriving. But did you know our native grey squirrels have been pushed out of their traditional range due to the disappearance of their native habitat of local oaks and black walnut trees? What you’ve been seeing are non-native eastern fox squirrels.

We have a half-dozen of these cute transplants living in our backyard, even though we live in the last section of Greater Los Angeles with a viable population of native Californian black walnut trees to feed local squirrels. The eastern fox squirrels are just more adaptable to urban life than their Californian country counterparts.

A map from the Southern California Squirrel Survey.

A map from the Southern California Squirrel Survey.

Jim Dines, a mammalogist at the Natural History Museum of Los Angeles County is now leading the charge in surveying the distribution of squirrels in Southern California. My wife signed herself up to observe and report back how these adaptive eastern transplants are doing, especially in these times when the stress of the drought is affecting both flora and fauna in innumerable ways. The responsibilities of a Citizen Scientist are modest: Surveying your yard for 15 minutes, twice a month, for one year, in search of squirrels, reptiles, amphibians, and snails and recording your observations (including submitting photos  based on your backyard surveys). It’s something my wife and I already do while enjoying the microcosm of life happening in our very own backyard up here in Mt. Washington.

To learn more about becoming a Citizen Scientist yourself, check out the various programs over at the NHM’s Citizen Science Program site.