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• 1. [Article] Biological diversity and third world development : a study of the transformation of an ecological concept into natural resource policy

  This work examined the transformation of the concept of biodiversity into natural resource policies of the U.S. Agency for International Development and the World Bank through 1988. The study identified ...

  Citation × Citation Citation Abstract Copy Title: Biological diversity and third world development : a study of the transformation of an ecological concept into natural resource policy Author: Vincent, Robert Montgomery This work examined the transformation of the concept of biodiversity into natural resource policies of the U.S. Agency for International Development and the World Bank through 1988. The study identified several groups as playing key roles in the transformation process. These were nongovernmental environmental organizations, the scientific community, and the U.S. Congress. As a framework for analysis, a Process Model is presented which depicts the process that transforms a scientific concept into natural resource policy. As a result of this research, modifications to the original Process Model are proposed. Though this study focuses on the scientific concept of biological diversity, it is suggested that the Process Model may be more broadly applied to other resource issues which follow the model's general steps of concept formulation, value identification, legislation development, and policy formulation. Several conclusions are reached from this study. One is that though there was little agreement about the concept of biodiversity within the scientific community, three broad themes evolved. These themes are ecosystem diversity, species diversity, and genetic diversity. Second, NGEO members did not adopt scientific concepts of biodiversity, but rather developed value positions with respect to biodiversity. These positions were presented to lawmakers the result being that biodiversity legislation was narrowly focused and did not fully reflect the three major diversity themes developed within the scientific community. Finally, policies developed by agencies responsible for implementing biodiversity legislation reflected Congressional intent and were equally narrowly focused. One consequence is that only selected major biodiversity themes are dealt with in agency policy, and this is reflected in agency funded programs to conserve biological diversity. Title: Biological diversity and third world development : a study of the transformation of an ecological concept into natural resource policy Author: Vincent, Robert Montgomery This work examined the transformation of the concept of biodiversity into natural resource policies of the U.S. Agency for International Development and the World Bank through 1988. The study identified several groups as playing key roles in the transformation process. These were nongovernmental environmental organizations, the scientific community, and the U.S. Congress. As a framework for analysis, a Process Model is presented which depicts the process that transforms a scientific concept into natural resource policy. As a result of this research, modifications to the original Process Model are proposed. Though this study focuses on the scientific concept of biological diversity, it is suggested that the Process Model may be more broadly applied to other resource issues which follow the model's general steps of concept formulation, value identification, legislation development, and policy formulation. Several conclusions are reached from this study. One is that though there was little agreement about the concept of biodiversity within the scientific community, three broad themes evolved. These themes are ecosystem diversity, species diversity, and genetic diversity. Second, NGEO members did not adopt scientific concepts of biodiversity, but rather developed value positions with respect to biodiversity. These positions were presented to lawmakers the result being that biodiversity legislation was narrowly focused and did not fully reflect the three major diversity themes developed within the scientific community. Finally, policies developed by agencies responsible for implementing biodiversity legislation reflected Congressional intent and were equally narrowly focused. One consequence is that only selected major biodiversity themes are dealt with in agency policy, and this is reflected in agency funded programs to conserve biological diversity. Close

• 2. [Article] Soil Property Effects on Willamette Daisy (Erigeron decumbens) within William L. Finley National Wildlife Refuge

  Plant species diversity plays an important role in maintaining ecosystem function and the services that ecosystems provide. Diversity is threatened by habitat loss, invasive species, and global climate ...

  Citation × Citation Citation Abstract Copy Title: Soil Property Effects on Willamette Daisy (Erigeron decumbens) within William L. Finley National Wildlife Refuge Author: Day, Emily S. Plant species diversity plays an important role in maintaining ecosystem function and the services that ecosystems provide. Diversity is threatened by habitat loss, invasive species, and global climate change. Willamette Daisy (Erigeron decumbens), an endangered species, has been reintroduced at two different sites (Field 29 and 8N) within William L. Finely Wildlife refuge, but it grows better at one site (Field 29) than the other (Field 8N). The purpose of the study was to determine if the differences in growth at the two sites could be caused by differences in soil properties, and determine soil conditions conducive for growth. We grew E. decumbens in soil collected from each field in a greenhouse with sterile and unsterilized treatments and performed a soil analysis on samples from each field. Soil sterilization had a significantly negative effect on plant survivorship, suggesting soil biota improves establishment of E. decumbens. Field 29 had significantly higher TN, TC, and pH than Field 8N, which may be contributing to the observed differences. Results from this study suggest that these soil properties could benefit E. decumbens growth in the wild, and information on soil conditions could improve reintroduction site selection and recovery of this endangered species. Title: Soil Property Effects on Willamette Daisy (Erigeron decumbens) within William L. Finley National Wildlife Refuge Author: Day, Emily S. Plant species diversity plays an important role in maintaining ecosystem function and the services that ecosystems provide. Diversity is threatened by habitat loss, invasive species, and global climate change. Willamette Daisy (Erigeron decumbens), an endangered species, has been reintroduced at two different sites (Field 29 and 8N) within William L. Finely Wildlife refuge, but it grows better at one site (Field 29) than the other (Field 8N). The purpose of the study was to determine if the differences in growth at the two sites could be caused by differences in soil properties, and determine soil conditions conducive for growth. We grew E. decumbens in soil collected from each field in a greenhouse with sterile and unsterilized treatments and performed a soil analysis on samples from each field. Soil sterilization had a significantly negative effect on plant survivorship, suggesting soil biota improves establishment of E. decumbens. Field 29 had significantly higher TN, TC, and pH than Field 8N, which may be contributing to the observed differences. Results from this study suggest that these soil properties could benefit E. decumbens growth in the wild, and information on soil conditions could improve reintroduction site selection and recovery of this endangered species. Close

• 3. [Article] Human Visitation in the Rocky Intertidal and its Effects on Abundance of Algal and Invertebrate Species

  The rocky intertidal is a diverse ecosystem with a variety of species and ecological interactions. Many biotic and abiotic interactions act together to restrict the abundance and distribution of species. ...

  Citation × Citation Citation Abstract Copy Title: Human Visitation in the Rocky Intertidal and its Effects on Abundance of Algal and Invertebrate Species Author: Silbernagel, Justin J. The rocky intertidal is a diverse ecosystem with a variety of species and ecological interactions. Many biotic and abiotic interactions act together to restrict the abundance and distribution of species. Anthropogenic effects can have an important impact on species abundance and distribution as well. This study looks at how human visitation affects community structure in the rocky intertidal along the Oregon coast. Areas of high human visitation were found to have lower species richness than areas of low visitation in the lower vertical zones of the rocky intertidal. However, species richness was found to be higher in high visitation areas in the highest intertidal zone. Abundance of species differed between areas of high and low human visitation, but showed few overall significant trends. Title: Human Visitation in the Rocky Intertidal and its Effects on Abundance of Algal and Invertebrate Species Author: Silbernagel, Justin J. The rocky intertidal is a diverse ecosystem with a variety of species and ecological interactions. Many biotic and abiotic interactions act together to restrict the abundance and distribution of species. Anthropogenic effects can have an important impact on species abundance and distribution as well. This study looks at how human visitation affects community structure in the rocky intertidal along the Oregon coast. Areas of high human visitation were found to have lower species richness than areas of low visitation in the lower vertical zones of the rocky intertidal. However, species richness was found to be higher in high visitation areas in the highest intertidal zone. Abundance of species differed between areas of high and low human visitation, but showed few overall significant trends. Close

• 4. [Article] The development of a distribution- and growth-prediction model for the environmental grid

  Further development of an environmental grid for interpreting plant distribution and growth took place this last year as an attempt to solve problems associated with spatial diversity in ecosystems. Special ...

  Citation × Citation Citation Abstract Copy Title: The development of a distribution- and growth-prediction model for the environmental grid Author: Waring, Richard H., University of Washington, U.S. International Biological Program. Coniferous Forest Biome Further development of an environmental grid for interpreting plant distribution and growth took place this last year as an attempt to solve problems associated with spatial diversity in ecosystems. Special emphasis was placed on developing more universal integrated indexes to environment, ones that might permit wide extrapolation throughout the range of at least one or two of the more widely distributed forest species ... It was the task of this project to integrate these variables to more readily explain and predict plant distribution and growth. Title: The development of a distribution- and growth-prediction model for the environmental grid Author: Waring, Richard H., University of Washington, U.S. International Biological Program. Coniferous Forest Biome Further development of an environmental grid for interpreting plant distribution and growth took place this last year as an attempt to solve problems associated with spatial diversity in ecosystems. Special emphasis was placed on developing more universal integrated indexes to environment, ones that might permit wide extrapolation throughout the range of at least one or two of the more widely distributed forest species ... It was the task of this project to integrate these variables to more readily explain and predict plant distribution and growth. Close

• 5. [Article] Urban Ecosystem Services: Tree Diversity and Stability of Tropospheric Ozone Removal

  Urban forests provide important ecosystem services, such as urban air quality improvement by removing pollutants. While robust evidence exists that plant physiology, abundance, and distribution within ...

  Citation × Citation Citation Abstract Copy Title: Urban Ecosystem Services: Tree Diversity and Stability of Tropospheric Ozone Removal Author: Manes, Fausto, Incerti, Guido, Salvatori, Elisabetta, Vitale, Marcello, Ricotta, Carlo, Costanza, Robert Year: 2012 Urban forests provide important ecosystem services, such as urban air quality improvement by removing pollutants. While robust evidence exists that plant physiology, abundance, and distribution within cities are basic parameters affecting the magnitude and efficiency of air pollution removal, little is known about effects of plant diversity on the stability of this ecosystem service. Here, by means of a spatial analysis integrating system dynamic modeling and geostatistics, we assessed the effects of tree diversity on the removal of tropospheric ozone (O3) in Rome, Italy, in two years (2003 and 2004) that were very different for climatic conditions and ozone levels. Different tree functional groups showed complementary uptake patterns, related to tree physiology and phenology, maintaining a stable community function across different climatic conditions. Our results, although depending on the city-specific conditions of the studied area, suggest a higher function stability at increasing diversity levels in urban ecosystems. In Rome, such ecosystem services, based on published unitary costs of externalities and of mortality associated with O3, can be prudently valued to roughly US $2 and $3 million/year, respectively. Title: Urban Ecosystem Services: Tree Diversity and Stability of Tropospheric Ozone Removal Author: Manes, Fausto, Incerti, Guido, Salvatori, Elisabetta, Vitale, Marcello, Ricotta, Carlo, Costanza, Robert Year: 2012 Urban forests provide important ecosystem services, such as urban air quality improvement by removing pollutants. While robust evidence exists that plant physiology, abundance, and distribution within cities are basic parameters affecting the magnitude and efficiency of air pollution removal, little is known about effects of plant diversity on the stability of this ecosystem service. Here, by means of a spatial analysis integrating system dynamic modeling and geostatistics, we assessed the effects of tree diversity on the removal of tropospheric ozone (O3) in Rome, Italy, in two years (2003 and 2004) that were very different for climatic conditions and ozone levels. Different tree functional groups showed complementary uptake patterns, related to tree physiology and phenology, maintaining a stable community function across different climatic conditions. Our results, although depending on the city-specific conditions of the studied area, suggest a higher function stability at increasing diversity levels in urban ecosystems. In Rome, such ecosystem services, based on published unitary costs of externalities and of mortality associated with O3, can be prudently valued to roughly US $2 and $3 million/year, respectively. Close

• 6. [Article] Oregon Natural Areas Plan

  The rich diversity of ecosystems and native plants and animals is one of Oregon's most distinctive and valued qualities. Our state contains rain forests, dry forests, oak woodlands, alpine meadows, prairies, ...

  Citation × Citation Citation Abstract Copy Title: Oregon Natural Areas Plan Author: Oregon Natural Heritage Advisory Council Year: 2010 The rich diversity of ecosystems and native plants and animals is one of Oregon's most distinctive and valued qualities. Our state contains rain forests, dry forests, oak woodlands, alpine meadows, prairies, deserts, marshes, estuaries, dunes, rocky headlands, lakes and streams. There are a number of reasons it is so diverse. First are the extremes of climate, with rainfall ranging from over 200 inches a year along Oregon’s north coast, to less than 7 inches a year in the Alvord Desert, and temperatures from the very mild banana belt along the coast near the California border to the extremes of the high alpine areas of the Wallowa Mountains. Secondly, Oregon is diverse geographically and geologically, having ancient serpentine landscapes in the Siskiyou Mountains and recent volcanics in the Cascades and the deepest gorge in North America at Hells Canyon. Lastly, Oregon is a floristic crossroads, with arctic boreal species finding their southern limit, Rocky Mountain species common in northeastern Oregon, Great Basin species in southeastern Oregon, and California coastal and Sierra species in the southwest, all mixing with native northwestern taxa to create a wide array of habitats. Title: Oregon Natural Areas Plan Author: Oregon Natural Heritage Advisory Council Year: 2010 The rich diversity of ecosystems and native plants and animals is one of Oregon's most distinctive and valued qualities. Our state contains rain forests, dry forests, oak woodlands, alpine meadows, prairies, deserts, marshes, estuaries, dunes, rocky headlands, lakes and streams. There are a number of reasons it is so diverse. First are the extremes of climate, with rainfall ranging from over 200 inches a year along Oregon’s north coast, to less than 7 inches a year in the Alvord Desert, and temperatures from the very mild banana belt along the coast near the California border to the extremes of the high alpine areas of the Wallowa Mountains. Secondly, Oregon is diverse geographically and geologically, having ancient serpentine landscapes in the Siskiyou Mountains and recent volcanics in the Cascades and the deepest gorge in North America at Hells Canyon. Lastly, Oregon is a floristic crossroads, with arctic boreal species finding their southern limit, Rocky Mountain species common in northeastern Oregon, Great Basin species in southeastern Oregon, and California coastal and Sierra species in the southwest, all mixing with native northwestern taxa to create a wide array of habitats. Close

• 7. [Article] Biodiversity Conservation: The Key Is Reducing Meat Consumption

  Access to this item has been restricted by repository administrators at the request of the publisher, Elsevier, until July 29, 2017.

  Citation × Citation Citation Abstract Copy Title: Biodiversity Conservation: The Key Is Reducing Meat Consumption Author: Machovina, Brian, Feeley, Kenneth J., Ripple, William J. Access to this item has been restricted by repository administrators at the request of the publisher, Elsevier, until July 29, 2017. Title: Biodiversity Conservation: The Key Is Reducing Meat Consumption Author: Machovina, Brian, Feeley, Kenneth J., Ripple, William J. Access to this item has been restricted by repository administrators at the request of the publisher, Elsevier, until July 29, 2017. Close

• 8. [Article] Stand Structure of Old Growth Dry Mixed Conifer Forests in the Deschutes and Ochoco National Forests.

  Old-growth dry-mixed conifer forests are valued as habitats for late seral forest species, for the ecosystem services and landscape diversity they provide, and for their aesthetic appeal. The structure ...

  Citation × Citation Citation Abstract Copy Title: Stand Structure of Old Growth Dry Mixed Conifer Forests in the Deschutes and Ochoco National Forests. Author: Merschel, Andrew G. Old-growth dry-mixed conifer forests are valued as habitats for late seral forest species, for the ecosystem services and landscape diversity they provide, and for their aesthetic appeal. The structure of these forests has been heavily altered by historic logging of overstory ponderosa pine and Douglas-fir. Additionally, changes in fire regime have altered understory density in these forests to an unknown extent. Conserving remaining stands and facilitating old-growth development in disturbed stands are objectives of the Deschutes and Ochoco National Forests. This investigation addressed these objectives with two separate analyses. The first analysis was an accuracy assessment of the GNN forest vegetation map’s ability to predict old-growth drymixed conifer structure at a site scale and at a landscape scale. This analysis determined that the GNN map is an adequate tool for identifying old-growth stands at a site scale, and was highly accurate at predicting dry-mixed conifer forest vegetation at a landscape scale. The second analysis characterized present day and historic stand structure of old-growth dry-mixed conifer forests, and described how stand structure varied across the Deschutes and Ochoco National Forests. The second analysis determined future research should investigate the growth rate of understory ponderosa pine and Douglas-fir under varying density levels. Title: Stand Structure of Old Growth Dry Mixed Conifer Forests in the Deschutes and Ochoco National Forests. Author: Merschel, Andrew G. Old-growth dry-mixed conifer forests are valued as habitats for late seral forest species, for the ecosystem services and landscape diversity they provide, and for their aesthetic appeal. The structure of these forests has been heavily altered by historic logging of overstory ponderosa pine and Douglas-fir. Additionally, changes in fire regime have altered understory density in these forests to an unknown extent. Conserving remaining stands and facilitating old-growth development in disturbed stands are objectives of the Deschutes and Ochoco National Forests. This investigation addressed these objectives with two separate analyses. The first analysis was an accuracy assessment of the GNN forest vegetation map’s ability to predict old-growth drymixed conifer structure at a site scale and at a landscape scale. This analysis determined that the GNN map is an adequate tool for identifying old-growth stands at a site scale, and was highly accurate at predicting dry-mixed conifer forest vegetation at a landscape scale. The second analysis characterized present day and historic stand structure of old-growth dry-mixed conifer forests, and described how stand structure varied across the Deschutes and Ochoco National Forests. The second analysis determined future research should investigate the growth rate of understory ponderosa pine and Douglas-fir under varying density levels. Close

• 9. [Article] Biogeochemical Stoichiometry of Antarctic Dry Valley Ecosystems

  Among aquatic and terrestrial landscapes of the McMurdo Dry Valleys, Antarctica, ecosystem stoichiometry ranges from values near the Redfield ratios for C:N:P to nutrient concentrations in proportions ...

  Citation × Citation Citation Abstract Copy Title: Biogeochemical Stoichiometry of Antarctic Dry Valley Ecosystems Author: Barrett, John E., Virginia, Ross A., Lyons, W. Berry, McKnight, Diane M., Priscu, John Charles, Doran, Peter T., Fountain, Andrew G., Wall, Diana H., Moorhead, D. L. Year: 2007 Among aquatic and terrestrial landscapes of the McMurdo Dry Valleys, Antarctica, ecosystem stoichiometry ranges from values near the Redfield ratios for C:N:P to nutrient concentrations in proportions far above or below ratios necessary to support balanced microbial growth. This polar desert provides an opportunity to evaluate stoichiometric approaches to understand nutrient cycling in an ecosystem where biological diversity and activity are low, and controls over the movement and mass balances of nutrients operate over 10–10⁶ years. The simple organisms (microbial and metazoan) comprising dry valley foodwebs adhere to strict biochemical requirements in the composition of their biomass, and when activated by availability of liquid water, they influence the chemical composition of their environment according to these ratios. Nitrogen and phosphorus varied significantly in terrestrial and aquatic ecosystems occurring on landscape surfaces across a wide range of exposure ages, indicating strong influences of landscape development and geochemistry on nutrient availability. Biota control the elemental ratio of stream waters, while geochemical stoichiometry (e.g., weathering, atmospheric deposition) evidently limits the distribution of soil invertebrates. We present a conceptual model describing transformations across dry valley landscapes facilitated by exchanges of liquid water and biotic processing of dissolved nutrients. We conclude that contemporary ecosystem stoichiometry of Antarctic Dry Valley soils, glaciers, streams, and lakes results from a combination of extant biological processes superimposed on a legacy of landscape processes and previous climates. Title: Biogeochemical Stoichiometry of Antarctic Dry Valley Ecosystems Author: Barrett, John E., Virginia, Ross A., Lyons, W. Berry, McKnight, Diane M., Priscu, John Charles, Doran, Peter T., Fountain, Andrew G., Wall, Diana H., Moorhead, D. L. Year: 2007 Among aquatic and terrestrial landscapes of the McMurdo Dry Valleys, Antarctica, ecosystem stoichiometry ranges from values near the Redfield ratios for C:N:P to nutrient concentrations in proportions far above or below ratios necessary to support balanced microbial growth. This polar desert provides an opportunity to evaluate stoichiometric approaches to understand nutrient cycling in an ecosystem where biological diversity and activity are low, and controls over the movement and mass balances of nutrients operate over 10–10⁶ years. The simple organisms (microbial and metazoan) comprising dry valley foodwebs adhere to strict biochemical requirements in the composition of their biomass, and when activated by availability of liquid water, they influence the chemical composition of their environment according to these ratios. Nitrogen and phosphorus varied significantly in terrestrial and aquatic ecosystems occurring on landscape surfaces across a wide range of exposure ages, indicating strong influences of landscape development and geochemistry on nutrient availability. Biota control the elemental ratio of stream waters, while geochemical stoichiometry (e.g., weathering, atmospheric deposition) evidently limits the distribution of soil invertebrates. We present a conceptual model describing transformations across dry valley landscapes facilitated by exchanges of liquid water and biotic processing of dissolved nutrients. We conclude that contemporary ecosystem stoichiometry of Antarctic Dry Valley soils, glaciers, streams, and lakes results from a combination of extant biological processes superimposed on a legacy of landscape processes and previous climates. Close

• 10. [Article] Convergence of Microclimate in Residential Landscapes Across Diverse Cities in the United States

  Context The urban heat island (UHI) is a welldocumented pattern of warming in cities relative to rural areas. Most UHI research utilizes remote sensing methods at large scales, or climate sensors in single ...

  Citation × Citation Citation Abstract Copy Title: Convergence of Microclimate in Residential Landscapes Across Diverse Cities in the United States Author: Hall, Sharon J., Learned, J, Ruddell, Benjamin, Larson, Kelli L., Cavender-Bares, Jeannine, Bettez, Neil D., Groffman, Peter M., Grove, J. Morgan, Heffernan, James B., Hobbie, Sarah E., Larson, Kristen, Morse, Jennifer L., Neill, Christopher, Nelson, Kristen C., O'Neil-Dunne, Jarlath, Ogden, Laura A., Pataki, Diane E., Pearse, William D., Polsky, Colin, Chowdhury, Rinku Roy, Steele, Meredith K., Trammell, Tara Year: 2015 Context The urban heat island (UHI) is a welldocumented pattern of warming in cities relative to rural areas. Most UHI research utilizes remote sensing methods at large scales, or climate sensors in single cities surrounded by standardized land cover. Relatively few studies have explored continental-scale climatic patterns within common urban microenvironments such as residential landscapes that may affect human comfort. Objectives We tested the urban homogenization hypothesis which states that structure and function in cities exhibit ecological ‘‘sameness’’ across diverse regions relative to the native ecosystems they replaced. Methods We deployed portable micrometeorological sensors to compare air temperature and humidity in residential yards and native landscapes across six U.S. cities that span a range of climates (Phoenix, AZ; Los Angeles, CA; Minneapolis-St. Paul, MN; Boston, MA; Baltimore, MD; and Miami, FL). Results Microclimate in residential ecosystems was more similar among cities than among native ecosystems, particularly during the calm morning hours. Maximum regional actual evapotranspiration (AET) was related to the morning residential microclimate effect. Residential yards in cities with maximum AET \50–65 cm/year (Phoenix and Los Angeles) were generally cooler and more humid than nearby native shrublands during summer mornings, while yards in cities above this threshold were generally warmer (Baltimore and Miami) and drier (Miami) than native forests. On average, temperature and absolute humidity were *6 % less variable among residential ecosystems than among native ecosystems from diverse regions. Conclusions These data suggest that common residential land cover and structural characteristics lead to microclimatic convergence across diverse regions at the continental scale. Title: Convergence of Microclimate in Residential Landscapes Across Diverse Cities in the United States Author: Hall, Sharon J., Learned, J, Ruddell, Benjamin, Larson, Kelli L., Cavender-Bares, Jeannine, Bettez, Neil D., Groffman, Peter M., Grove, J. Morgan, Heffernan, James B., Hobbie, Sarah E., Larson, Kristen, Morse, Jennifer L., Neill, Christopher, Nelson, Kristen C., O'Neil-Dunne, Jarlath, Ogden, Laura A., Pataki, Diane E., Pearse, William D., Polsky, Colin, Chowdhury, Rinku Roy, Steele, Meredith K., Trammell, Tara Year: 2015 Context The urban heat island (UHI) is a welldocumented pattern of warming in cities relative to rural areas. Most UHI research utilizes remote sensing methods at large scales, or climate sensors in single cities surrounded by standardized land cover. Relatively few studies have explored continental-scale climatic patterns within common urban microenvironments such as residential landscapes that may affect human comfort. Objectives We tested the urban homogenization hypothesis which states that structure and function in cities exhibit ecological ‘‘sameness’’ across diverse regions relative to the native ecosystems they replaced. Methods We deployed portable micrometeorological sensors to compare air temperature and humidity in residential yards and native landscapes across six U.S. cities that span a range of climates (Phoenix, AZ; Los Angeles, CA; Minneapolis-St. Paul, MN; Boston, MA; Baltimore, MD; and Miami, FL). Results Microclimate in residential ecosystems was more similar among cities than among native ecosystems, particularly during the calm morning hours. Maximum regional actual evapotranspiration (AET) was related to the morning residential microclimate effect. Residential yards in cities with maximum AET \50–65 cm/year (Phoenix and Los Angeles) were generally cooler and more humid than nearby native shrublands during summer mornings, while yards in cities above this threshold were generally warmer (Baltimore and Miami) and drier (Miami) than native forests. On average, temperature and absolute humidity were *6 % less variable among residential ecosystems than among native ecosystems from diverse regions. Conclusions These data suggest that common residential land cover and structural characteristics lead to microclimatic convergence across diverse regions at the continental scale. Close