Who conserves and who approves? Predicting water conservation intentions in urban landscapes with referent groups beyond the traditional ‘important others’

Water conservation efforts in urban landscapes have increased the need for water-wise-plants. A potential source includes multiple native, drought-adapted species. A lack of researched propagation protocols makes commercial production of many species difficult. We examined germination of three native plant species (Purshia stansburiana, Cercocarpus ledifolius, and Forestiera pubescens) in three substrates. Both P. stansburiana and C. ledifolius are endemic to semiarid areas. Forestiera pubescens is found in riparian areas but is drought hardy once established. Stratified seed of each were sown in substrates varying in organic matter (OM) content and water-holding porosity (WHP) characteristics: (1) a commercial germination mix (83% OM); (2) a self-blended combination of a commercial potting soil mixed volumetrically 1:1 with vermiculite (37% OM); and (3) a calcined clay (0% OM). Germination was monitored for 60 days. Percent germination was highest in the calcined clay for each species evaluated (P. stansburiana: 63%, C. ledifolius: 51% and F. pubescens: 83%). These rates were at least 25% greater than the next best medium, the self-blended substrate. The commercial germination blend was the least favorable for germination. These results suggest that the common commercial practice of using germination substrates may not be suited to germinating many species native to arid areas.

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Landscape Preferences and Water Conservation Choices of Residents in a High Desert Environment

HortTechnology ◽

10.21273/horttech.20.2.308 ◽

2010 ◽

Vol 20 (2) ◽

pp. 308-314 ◽

Cited By ~ 18

Author(s):

Rolston St. Hilaire ◽

Dawn M. VanLeeuwen ◽

Patrick Torres

Keyword(s):

Water Conservation ◽

Negative Relationship ◽

High Water ◽

Conservation Strategies ◽

Urban Landscapes ◽

Desert Plants ◽

Water Shortages ◽

Residential Landscapes ◽

Willingness To Use ◽

High Desert

We surveyed homeowners with residential landscapes in Santa Fe, NM, to determine their attitudes toward high desert plants and to assess their preferences for urban landscapes and water conservation strategies in a high desert urban environment. While there was low acceptance for the traditional turf lawn, 64% of residents agreed that high desert plants provided the variety they needed in their residential landscapes and 92% of residents would use high desert plants to landscape their front yard. Homeowners had a strong preference for retaining their current desert landscapes and converting traditional landscapes to high desert-adapted landscapes. Logistic regression revealed a negative relationship between length of residency in the southwestern United States and the willingness to use high desert plants. When homeowners who irrigated their landscape were asked whether water shortages, environmental concerns, information on water, city regulations, high water bills, or water rate increases would cause them to use less water on their landscapes, the highest level of agreement (94%) was for water shortages. Eighty-eight percent of respondents agreed that they liked any type of landscape that contains interesting features and is well planned. We conclude that homeowners have a preference for desert-adapted landscapes and agree that high desert plants provide an adequate palette of plants for urban landscapes. Additionally, the length of residency in the southwestern U.S. and the possibility of water shortages have the potential to impact water conservation strategies in high desert urban landscapes.

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Efficient Water Use in Residential Urban Landscapes

HortScience ◽

10.21273/hortsci.43.7.2081 ◽

2008 ◽

Vol 43 (7) ◽

pp. 2081-2092 ◽

Cited By ~ 79

Author(s):

Rolston St. Hilaire ◽

Michael A. Arnold ◽

Don C. Wilkerson ◽

Dale A. Devitt ◽

Brian H. Hurd ◽

...

Keyword(s):

United States ◽

Water Conservation ◽

Urban Areas ◽

Management Practices ◽

Urban Landscape ◽

The United States ◽

Urban Landscapes ◽

Climate Control ◽

Water Supplies ◽

Aesthetic Appearance

In the United States, urban population growth, improved living standards, limited development of new water supplies, and dwindling current water supplies are causing the demand for treated municipal water to exceed the supply. Although water used to irrigate the residential urban landscape will vary according to factors such as landscape type, management practices, and region, landscape irrigation can vary from 40% to 70% of household use of water. So, the efficient use of irrigation water in urban landscapes must be the primary focus of water conservation. In addition, plants in a typical residential landscape often are given more water than is required to maintain ecosystem services such as carbon regulation, climate control, and preservation of aesthetic appearance. This implies that improvements in the efficiency of landscape irrigation will yield significant water savings. Urban areas across the United States face different water supply and demand issues and a range of factors will affect how water is used in the urban landscape. The purpose of this review is to summarize how irrigation and water application technologies; landscape design and management strategies; the relationship among people, plants, and the urban landscape; the reuse of water resources; economic and noneconomic incentives; and policy and ordinances impact the efficient use of water in the urban landscape.

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Influence of Irrigation Regime on Water Stress and Growth of Ligustrum japonicum and Myrica cerifera During Establishment

Journal of Environmental Horticulture ◽

10.24266/0738-2898.32.1.34 ◽

2014 ◽

Vol 32 (1) ◽

pp. 34-38

Author(s):

Brian J. Pearson ◽

Heather Bass ◽

Sloane M. Scheiber ◽

Richard C. Beeson

Keyword(s):

Water Stress ◽

Water Conservation ◽

Native Species ◽

Growth Index ◽

Fine Sand ◽

Urban Landscapes ◽

Myrica Cerifera ◽

Cumulative Stress ◽

Irrigation Regimes ◽

Ligustrum Japonicum

Native plants are often promoted for water conservation in urban landscapes. However, direct comparisons between native and introduced species utilizing physiological measures of plant water stress are unavailable to support or refute such recommendations. Ligustrum japonicum and Myrica cerifera, representing evergreen introduced and native species, respectively, were selected based on similar landscape function, non-stressed photosynthetic rates, and water use efficiencies. Both species were transplanted into a fine sand soil to evaluate establishment rates and growth characteristics under two irrigation regimes, irrigated either daily or every 3 d at 1.3 cm (0.5 in) of irrigation per event for the first 8 months after transplanting (MAT). Water potentials were recorded on two consecutive days each month, with cumulative stress intervals calculated. Water potential was significantly influenced by day of water stress level. On days without irrigation, water stress was generally greater and affected growth. Of the two species, Myrica irrigated daily had the greatest shoot growth, yet plants receiving irrigation every 3 d had the lowest root mass and biomass 8 MAT. In contrast, Ligustrum exhibited no differences in most parameters measured between irrigation regimes except for growth index. These contrasting differences stem from different strategies for coping with water stress.

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Water Deficit Stress Responses of Three Native Australian Ornamental Herbaceous Wildflower Species for Water-wise Landscapes

HortScience ◽

10.21273/hortsci.44.5.1358 ◽

2009 ◽

Vol 44 (5) ◽

pp. 1358-1365 ◽

Cited By ~ 4

Author(s):

Roger Kjelgren ◽

Lixue Wang ◽

Daryl Joyce

Keyword(s):

Water Potential ◽

Soil Water ◽

Water Use ◽

Stress Responses ◽

Water Conservation ◽

Plant Biomass ◽

Stomatal Closure ◽

Water Deficit Stress ◽

Urban Landscapes ◽

Volume Data

Perennial wildflower species are important but not well-understood elements in water-wise landscaping that anchors urban water conservation programs in arid climates. Comparative growth and physiological responses to soil substrate drying of three herbaceous Australian ornamental species from habitats of variable moisture regimes were investigated in the context of isohydric and anisohydric behavior. Clonal Orthosiphon aristatus, Dianella revoluta ‘Breeze’, and Ptilotus nobilis plants were container-grown individually and competitively together in two separate studies. In both studies, plants were water-stressed through cyclical dry downs. We measured stomatal conductance (g S), soil water content, and water potential during each study and osmotic adjustment estimated from pressure-volume data and plant biomass at the end of each study. O. aristatus, a rainforest species, fit a general anisohydric model of high water use and more negative water potential during soil drying until stomatal closure and leaf wilting. D. revolata and P. nobilis, indigenous to Australia's dry interior, fit a general isohydric, drought-tolerant model of stomatal closure from water deficits that moderates leaf water potential but through different mechanisms. P. nobilis and D. revolata moderate water use and maintain acceptable aesthetic performance under water stress, suitable for mixed low-water landscape plantings. O. aristatus would not be suitable for low-water urban landscapes, either isolated or in mixed plantings, because of high soil water depletion and wilting.

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286 Plant Life Form Frequency, Diversity, and Irrigation Application in Urban Residential Landscapes

HortScience ◽

10.21273/hortsci.34.3.491e ◽

1999 ◽

Vol 34 (3) ◽

pp. 491E-491 ◽

Cited By ~ 4

Author(s):

Cathleen A. Peterson ◽

L. Brooke McDowell ◽

Chris A. Martin

Keyword(s):

Species Diversity ◽

Plant Species ◽

Water Conservation ◽

Area Coverage ◽

Tropical Species ◽

Urban Landscapes ◽

Irrigation Application ◽

Residential Landscapes ◽

Canopy Area ◽

Central Arizona

Heightened awareness of ecological concerns have prompted many municipalities to promote water conservation through landscape design. In central Arizona, urban residential landscapes containing desert-adapted plant species are termed xeriscapes, while those containing temperate or tropical species and turf are termed mesoscapes. Research was conducted to ascertain landscape plant species diversity, tree, shrub, and ground cover frequency; landscape canopy area coverage; and monthly irrigation application volumes for xeric and mesic urban residential landscapes. The residential urban landscapes were located in Tempe and Phoenix, Ariz., and all were installed initially between 1985 and 1995. Although species composition of xeric and mesic landscapes was generally dissimilar, both landscape types had comparable species diversity. Mesoscapes had significantly more trees and shrubs and about 2.3 times more canopy area coverage per landscaped area than xeriscapes. Monthly irrigation application volumes per landscaped surface area were higher for xeriscapes. Even though human preference for xeric landscape plants may be ecological in principle, use of desert-adapted species in central Arizona urban residential landscape settings might not result in less landscape water use compared with mesic landscapes.

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Water Stress and Growth of Native and Introduced Shrub Species as Influenced by Irrigation Regime

HortScience ◽

10.21273/hortsci.41.4.999d ◽

2006 ◽

Vol 41 (4) ◽

pp. 999D-999

Author(s):

Sloane M. Scheiber ◽

Richard C. Beeson ◽

Heather Bass

Keyword(s):

Water Stress ◽

Water Conservation ◽

Native Species ◽

Growth Index ◽

Dry Mass ◽

Plant Performance ◽

Urban Landscapes ◽

Plant Water ◽

Growth Responses ◽

Irrigation Regimes

Native plants are often promoted as an approach for water conservation in urban landscapes. However, information regarding plant water needs is based primarily upon anecdotal observations of plant performance. Direct comparisons between native and introduced species using physiological measures of plant water stress are unavailable to support or refute such recommendations. Ligustrum japonicum and Myrica cerifera, representing an introduced and native species, respectively, were transplanted into a fine sand soil to evaluate establishment rates and growth characteristics under two irrigation regimes. Each species was irrigated either daily or every 3 days and received 1.3 cm of irrigation per event for 8 months after transplant. Predawn, midday, and dusk water potentials were recorded on three consecutive days monthly, with cumulative stress intervals calculated. Height, growth indices, shoot dry mass, root dry mass and leaf area were also recorded. Water potential was significantly influenced by day of water stress level. On days without irrigation, water stress was generally greater and affected growth. Myrica irrigated daily had the greatest growth, yet plants receiving irrigation every 3 days had the least growth and greater leaf drop. In contrast, for Ligustrum there were no differences between irrigation regimes in growth responses except for growth index.

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A Method to Quantitatively Classify Residential Urban Landscapes in a Desert Environment

HortTechnology ◽

10.21273/horttech.23.4.474 ◽

2013 ◽

Vol 23 (4) ◽

pp. 474-481

Author(s):

Malik G. Al-Ajlouni ◽

Dawn M. VanLeeuwen ◽

Michael N. DeMers ◽

Rolston St. Hilaire

Keyword(s):

Water Conservation ◽

Sampling Procedure ◽

Urban Landscapes ◽

Desert Environment ◽

Landscape Type ◽

Quantitative Classification ◽

Quantitative Evidence ◽

Residential Landscapes ◽

The Common ◽

Landscape Types

The apparent heterogeneity of human-generated materials in residential urban landscapes sustains concerns that the quantitative classification of urban residential landscapes is impossible. The objective of this research was to develop a method to quantitatively classify urban residential landscapes in a desert environment. Using a purposive sampling procedure, we studied the landscapable area around each of 54 residential homes in Las Cruces, NM. All materials in the landscape were identified, measured, and categorized. Using 30% as the cutoff to indicate that a material was dominant in the landscape, we classified 93% of all landscapes into nine common landscape types. Mulch-dominant landscapes were the most common, and landscape types differed between front- and backyards. Shrubs did not feature prominently in any of the common landscape types. Our classification method clearly identifies multiple landscape types, and for the first time, provides quantitative evidence that landscape types are distributed differently in front- and backyard landscapes in the desert environment of Las Cruces. Information on common landscape types will be valuable to landscape horticulturists wanting to craft water conservation plans that are landscape specific if the common landscape type can be linked to a landscape water budget.

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