Background gardens increase regional bird diversity • Earth.com
Bird populations are declining across the United States as their preferred habitats are replaced. This is especially true in urban areas where impermeable surfaces and man-made structures predominate. However, a recent study of bird diversity in six U.S. cities found that the way people manage and design their own backyards has the potential to increase wild bird habitat and improve biodiversity in the area. regional scale.
The research was co-led by Susannah Lerman of the USDA Forest Service and Desirée L. Narango of the City University of New York. The team recorded bird diversity in four types of residential gardens and in nature parks in six cities with very different climatic conditions, including Baltimore, Boston, Los Angeles, Miami, Minneapolis and Phoenix.
Urbanization generally leads to the homogenization of biodiversity because fewer different habitat types are available for birds. Additionally, bird communities in urban areas contain fewer native species and have lower conservation value. But few studies have explored whether or how land management by urban residents can improve the negative effects of this homogenization on species composition.
The researchers tested the effects of local characteristics (backyard land management) and neighborhood-scale (amount of impermeable surface area and tree cover) on the diversity of breeding birds in the six metropolitan areas. They considered six types of land management: two types of natural area parks (separate and adjacent to residential areas), two types of courtyards with conservation features (certified for wildlife and water conservation) and two types of courses dominated by lawn (high and low fertilizer application). ), in addition to the surrounding features on a neighborhood scale.
The results were similar in the six cities; species diversity was higher in backyards than in urban parks, although the parks are home to more species of conservation concern. In addition, courses certified as wildlife habitat through the National Wildlife Federation certification program supported a greater variety of bird species compared to the more traditional landscaping of the courses that was dominated. by the lawn.
Within yard types, species richness was positively associated with the amount of tree cover in the neighborhood, and negatively correlated with the amount of impermeable surface in the neighborhood.
Experts also found that backyard bird species generated a great deal of public interest among the birding community, making backyard management very important to attract wildlife.
“This study shows that when people manage with wildlife in mind, households can contribute to conservation in their own backyards,” Lerman said. “And our gardens are often home to some of our most beloved backyard birds.”
According to the study authors, their results show that preserving natural areas, reducing impermeable surfaces and increasing tree canopy are key strategies for supporting bird diversity and conserving species of regional importance. .
Backyards – especially those managed for wildlife – support diverse and heterogeneous bird communities with great public interest that can advance conservation successfully in American residential landscapes.
“Scientists are finding that we can’t study cities in isolation,” Narango said. “It will improve bird conservation efforts if we can understand which management practices are effective in regions and nationally, and which are effective at a more local level.”
The research results were published today in the journal Ecological applications.
Through Alison bosman, Terre.com Editor-in-chief