Virginia I. Lohr

Responses to Scenes with Spreading, Rounded, and Conical Tree Forms

Research has shown that people typically give high aesthetic preference ratings to trees with spreading canopies, similar to those found on the African savanna. If the savanna hypothesis is correct, people likely will have strong emotional responses to such trees as well. In this study, preferences and emotional responses of 206 participants to viewing scenes with different tree forms and urban elements were examined. Slide images of spreading, rounded, or columnar trees, or inanimate objects in two urban scenes were created. As expected, participants found scenes with trees more attractive than scenes with inanimate objects, and they rated spreading trees more attractive than rounded or columnar trees. Participants reported more positive emotions when viewing trees compared to inanimate objects, and they were happier when viewing spreading trees compared with other tree forms. These results are consistent with the savanna hypothesis, with emotional responses relating to preferences for trees with spreading forms.

Particulate matter accumulation on horizontal surfaces in interiors: Influence of foliage plants

Abstract Particulate matter accumulation on horizontal surfaces was measured gravimetrically, at one week intervals, in two interior spaces. Interior plants were added to or removed from the rooms on a random schedule. Particulate matter accumulation was lower in both rooms when plants were present than when plants were absent. The location of particulate matter deposition was unaffected by the presence or absence of plants: collection dishes located near the corners of a room consistently accumulated less particulate matter than dishes in other locations, regardless of treatment. In addition, relative humidity was higher when plants were present.

Horticultural Science’s Role in Meeting the Need of Urban Populations

Horticultural products and services impact the health and well-being of urban populations. This is an extremely important group for horticultural scientists and researchers to serve: more than half of all people worldwide already live in urban areas, and more than two-thirds will do so by 2050. In this chapter we address the past, current, and future roles that horticultural science plays in the major issues of concern to public welfare: public health, environmental health, food security, and economic stability. Urban horticulture has important impacts on the health of the individual and the community, two concerns of public health. Documented individual health benefits include less depression and improved pregnancy outcomes from walking in or living near urban green spaces. Community gardens, parks, and other urban vegetation enhance community health by improving social interactions, such as family dynamics, and public safety, such as protection from crimes. Uses of plants to improve the urban environment include temperature modification, air pollution reduction, and water quality improvement. Impacts on biological diversity are mixed. Other negative impacts include the introduction of invasive species. Urban food security requires food in sufficient, nutritious, and affordable quantities. Providing this for all people is one of the greatest challenges for horticultural science. Potential solutions include increasing small-scale food production in urban areas by providing more community gardens or converting vacant lots. Horticulture contributes directly to urban economics through the production and sales of horticultural products by urban businesses. Indirect contributions from plants include higher property values and more productive employees. The increasing urbanization and aging of the human population is happening in conjunction with rising environmental destruction from global warming and climate change. Combining the traditional horticultural concern of feeding the world with an expanded understanding of the additional functions provided by horticultural products, the needs of urban people, and the opportunities to partner with professionals in other disciplines will be essential in the unpredictable future.

Plants and the Individual

The benefits that an individual can derive from plants have been discussed for thousands of years, yet historically, reports supporting many of these benefits have been anecdotal. The problem with anecdotal evidence involves its veracity: we cannot know if the implied effect is due to plants or other factors. Anecdotes are valuable, however, because they can give researchers ideas about experiments to conduct. In the last twenty years, studies testing hypotheses about how plants affect individuals have begun to appear. This paper briefly reviews the methods and results from a selection of these studies.