Fascinating! Excellent article on another aspect of climate change. Enjoy!
Fascinating! Excellent article on another aspect of climate change. Enjoy!
See you Friday!
Erik will share his experience and knowledge in designed landscapes, his passion for C-sequestration in urban soils, and his vision that launched the Willamette Valley Regenerative Landscape Coalition.
Webinar Location: https://ornrcs.adobeconnect.com/oshp/
Audio for the webinar will be delivered through your computer so have you headphones or speakers ready. We will use interactive tools through the webinar for discussion and questions.
Have and upcoming Soil Health related event? Let Cory know at email@example.com. We will showcase upcoming events during the webinar.
This article from the NY Times provides an entertaining, but mildly depressing perspective on the general decline of ecological conditions over time, but specifically how insects are generally overlooked as indicators of ecological degradation. One of the more interesting points made in the article is, I think, the concept of a “Shifting Baseline Syndrome”, the acceptance of current ecological conditions as the norm by each generation, even though those conditions have been declining over time. Makes perfect sense!
Earlier this month we developed a brief survey to assess consumer’s values on consistency in native plant choices. The survey was created primarily in response to a recent article in Hort Technology, a peer reviewed journal from the American Society for Horticultural Science. The article discusses release methods and marketing in the relatively new field of “Nativars”, the selection and propagation of native plants for specific phenotypic characteristics such as flower color, size, growth habit, or for specific qualities such as drought resistance expressed in an individual plant. The goal of these efforts is to expand consumer interest in native plants and increase the attractiveness and use of native plants in home horticulture. The idea is that native plants would be more marketable if they exhibited consistency in shape, color, size, and other features commonly desirable in urban landscapes.
For me, the effort to homogenize the inherent variability in native plant species is troubling. Many native plant landscapes are designed for resource savings, habitat quality, or the resilience of native plant communities. Each of those features depends on the genetic variability of native species. The ability of a landscape to survive and recover from drought, disturbance, disease, or pests is highly dependent on the plasticity of genetic variation, and much of that genetic variation is expressed through phenotypic properties. Propagating plants with the intent to decrease variability reduces the genetic adaptability of a population. This may have long-term consequences on naturally occurring populations of the same species in the same ecological region as the project in which nativars are installed, although literature explicitly addressing the genetic swamping potential of nativars is lacking.
Our survey addresses a more practical consideration; the preferences and values of consumers. It’s unclear if institutions promoting nativars evaluated consumer preference concerning the inconsistencies in native plants, or the reasons people choose native plants as the primary plant type for their landscapes. Those are the questions we targeted in our brief on-line survey.
We developed our survey through SurveyMonkey (surveymonkey.com) and released it on our nursery facebook page (https://www.facebook.com/Wintercreek-Nursery-357840746834/). The survey was “boosted” twice to illicit responses from three levels of separation from WinterCreek Nursery (the survey went to friends of friends of friends of WinterCreek). The survey included six questions about native plants, one question about the respondent’s location, and one open-ended question that allowed people to express additional thoughts. No personal information was gathered. We received a total of 124 responses from Oregon, Washington, California, and Texas.
Generally, consumers choose native plants for their ability to reduce water use, wildlife habitat value, and pollinator habitat value (Figure 1), and value genetic diversity over consistency in phenotypic characteristics (Figure 2). Flower shape, size, and color are less important than mature plant type and size, and consumers tend to choose plants based on apparent health of the plant at the nursery and the type of plant rather than consistency in appearance at maturity (Figure 3). Individual comments submitted throughout the survey suggest consumers have a broad understanding of the value of genetic diversity in native plants but desire more education on the subject, and consider variability an important factor in their choice of native plants as components of home landscapes.
Forty-eight comments were submitted by respondents (Table 1). The comments generally address five primary subjects: resource conservation, maintaining genetic variability, deer resistance, wildlife and pollinator habitat, and availability. These remarks reflect answers to questions in the survey and support survey results that indicate genetic variability in native plants is a desirable characteristic to consumers.
Rupp, et al. 2018. Native and Adapted Plant Introduction for Low-water Landscaping. HortTechnology August 2018 28:431-435; doi:10.21273/HORTTECH04044-18
Figure 1: Responses to question 1: Why do you choose native plants? Columns indicate percentage of responses for each option (N=124). Water conservation and habitat value are rated significantly higher than other options. The high score of Conservation Ethic suggests a broad understanding of environmental values of native plants and their potential to contribute to overall resource conservation; not only water. “Other” responses ranged from valuing genetic diversity to deer resistance.
Figure 2: Weighted averages of responses for four questions ranking effect of consistency in plant characteristics on choice by consumers. Responses were ranked 1 through 5 from “Not at all important” to “Extremely important.” The four questions are: 1) How important is consistency in plant shape when choosing natives for your landscape? 2) How important is consistency in plant size when choosing natives for your landscape? 3) How important is genetic diversity in your decision to use native plants? 4) How important is consistency in flower color when choosing natives for your landscape? Results show that consumers value genetic diversity in native plants more than phenotypic characteristics commonly targeted in nativar propagation. (N=124)
Figure 3: Ranking of desirable plant characteristics by respondents (N=124). Results indicate that the type of plant and the apparent health of nursery stock are significantly more important to consumers than consistency in flower color or the mature shape of a native plant. However, general plant characteristics such as flowering period and mature size are also important considerations when choosing native plants, reflecting aesthetic elements common in urban landscape design.
Table 1: Forty-eight comments submitted by survey respondents. The remarks target five primary subjects: resource conservation, genetic diversity, pollinator and wildlife habitat, deer resistance, and plant availability.
The use of native plants in landscapes is a choice people make for a variety of reasons. But the native plant nursery industry is beginning to question the market value of some characteristics unique to native plants — like variability in size or shape, or the inconsistencies in flower color, or regional differences in seasonality. There is a small movement to provide native plants with consistency in characteristics such as flower size or color, or drought tolerance by selecting individual plants displaying desirable characteristics for propagation.
This brief survey is intended to gain some understanding of customers concerns and preferences when choosing to purchase native plants for their landscapes. All responses will remain anonymous. Results will be summarized and presented in this blog, and may be used in research publications or conference presentations. Thank you for helping with this effort!
(You’ll need to copy and paste the address in a browser to open it. I can’t figure out how to make it a hotlink in this format… )
By Rick Martinson
We desperately need a wholesale shift in how we perceive, design, and install landscapes. Our industry has the opportunity to help create long-term solutions to effects of climate change and the expected shifts in timing, intensity, and duration of precipitation events. Water availability, use, and waste within the city has become a main focus of the Department of Public Works, and substantial effort is being made by the city and irrigation contractors to increase the efficient application of water through ensuring systems are designed and maintained correctly. However, water use will continue to be a contentious subject throughout the semi-arid west. Meeting future water restrictions will require creativity in how we design and construct landscapes in urban settings. One way to do that is through design and construction of projects based on the ecology of specific site locations.
Ecology based landscape design considers hydrology, soils, plant associations, and underlying geology of a project site. In ecological terms, designs take into consideration the biotic (living) and abiotic (non-living) aspects of a site and strive to balance the ecological function of a landscape with the aesthetic values of the property owner or manager. Emulating natural processes or creating landscapes with the intent and ability to “kick-start” many of the functions of natural systems, such as nutrient cycling or stormwater management, can also significantly reduce a created landscape’s requirements for water, fertilizers, and other inputs. These methods address the sustainability of a project, but more importantly, move beyond mere sustainability toward regeneration of ecosystem services that are generally lost through disturbances inherent in development and construction activities. Examples of ecosystem services include air and water purification, stormwater management, reduction of urban heat island effects, pollination, aesthetic quality, and other functions benefiting people and societies.
An effective approach to this type of work is the use of native vegetation appropriate for the specific project location. Ecological characteristics vary considerably, and working with vegetation adapted to specific environmental conditions increases a project’s efficiency through increased resiliency, inter and intra-species relationships, and preservation of community structure and existing energy flows. These qualities simply increase the efficient functioning of a created landscape, and reduce or eliminate the need for artificial inputs (such as water or fertilizers) resulting in an economic benefit while providing a sense of place and functional beauty.
Another approach is to utilize on-site resources to the greatest extent possible. Capture and control of stormwater is a common requirement in urban development, and is addressed in many Codes, Covenants and Restrictions (CC&R’s) in municipalities throughout the western United States. But shifting our view of stormwater as bothersome to a highly valued resource can encourage landscape designers and architects to include features designed to capture and use stormwater as a secondary or even primary irrigation source. An example of this is the creative design of vegetated bioswales. In many instances stormwater is directed off a roof, through a gutter, and down a spout or chain to a large hole in the ground filled with drainrock (a drywell). A more suitable use might be construction of a dry stream bed or vegetated swale designed to capture runoff from the downspout and use that seasonal moisture to create a unique climate and choose plants adapted to those seasonally moist areas. A number of native species naturally occur in similar environmental conditions, and can tolerate extremely dry soils during the heat of the summer. These types of features not only utilize a scarce resource, but add a unique aesthetic element to landscapes. Similarly, reusing soils and rock from excavation of a site as backfill and during landscape construction can help maintain some of the biological activity existing on site prior to disturbances. Projects designed to maintain or enhance the functional ecology of a project site have been shown to greatly reduce a landscapes dependence on human inputs such as water or fertilizers. Local municipalities can often supply examples of these types of projects.
One key element of landscapes designed to maximize efficiency is biodiversity. Although biodiversity has been defined in many different ways, the term generally refers to the range of organisms in an ecosystem. In a landscape setting, biodiversity is commonly used to refer to the number of plant species installed, and the diversity of soil organisms supporting the landscape. Maximizing both above-ground (plants) and below-ground (fungi, bacteria, nematodes, etc) diversity helps create a self-supporting and self-regulating landscape resistant to pests and resilient in response to changing environmental conditions. Research continues to provide examples of the essential relationship between plants and soil biota, and several companies provide commercial fungal and bacterial inoculants suitable for urban landscapes.
Our relationship with landscapes and many of our aesthetic values are a result of a long history of cultural values and marketing efforts of landscape, irrigation, or fertilizer companies. Recent drought conditions in much of the semi-arid western U.S. and a growing awareness of environmental issues by homeowners and contractors are challenging those historic views. Modification of municipal code, development of Best Management Practices (BMP’s), and an increase in application of Integrated Pest Management (IPM) techniques in project construction and maintenance are signs of a subtle shift in how we view and interact with created and managed environments.
But the number of projects addressing concerns over resource availability (predominantly water) is still small. An increased understanding and knowledge of environmental issues and how to address expected effects of climate change is critical for the continued viability of the landscape industry. New technology and shifts in design concepts and construction techniques within the green industry continue to improve efficiency of created landscapes, but some feel those changes are not fast enough or effective at addressing long-term sustainability of our industry. We as an industry can be proactive and act as leaders in the development of a truly sustainable future.