Sometime around June 2021 an idea started forming in my mind. I was starting a new job as a scientist in the Research and Conservation Department. I wanted to study the effects of genetic diversity on plant population performance. My background is in studying adaptation and persistence of wild populations of plants in changing environments. My new job was to look at related questions in the context of ecological restoration. </p> Ecological restoration is the process of returning ecological function following degradation to an ecosystem. One common method is planting native species. A major challenge, however, is establishment and long-term persistence of these native species. Some scientists and restoration practitioners argue that using plants that are the most locally adapted is best, while others espouse that using the most genetically diverse source(s) is likely best given environmental uncertainty. I wanted to design an experiment to test these ideas. </p> Two-hundred thousand seeds, 1,000 survey flags, 500 plots, 36 large spice shakers and 10 researchers later we had set up this experiment at two sites near Canyon City, CO. Next came a winter of hoping and thankfully above-average spring precipitation. Finally this past June, I started reaping the reward as we collected data on hundreds of seedlings that emerged in the research plots.</p> I thought I had designed the experiment to be fool proof such that any data we were able to collect would yield interesting results. However, as is so often the case in science, the data is complicated. It’s still too early to say if our results will give a clear picture to address our initial hypotheses. What is clear so far is that everything is context dependent. The results rely on multiple variables, some that we can measure and some that we cannot. </p> While this makes communicating the science challenging, it is not uncommon. So often in science we try to present clear stories, when in reality data is messy and results are inconclusive. I think it’s important to acknowledge this and even celebrate it. Science is iterative and slow, and while it’s not the only way of obtaining knowledge, it is a powerful method. My experiment might not yield the clear long-term dataset that I hoped for, but it is still valuable. I have learned a lot already from the experience and sharing the results, whatever they may be, will be important.</p> This article was contributed by April Goebl</strong>, assistant research scientist.</em> </p>
In the world of gardening, we often find ourselves immersed in the beauty of living plants. However, the intricacies of a garden extend far beyond the greenery. In the newly unveiled habitat gardens we explore the importance of organic and inorganic structures in supporting a thriving wildlife habitat.</p> All along the reimagined Birds and Bees Walk</a> you’ll encounter installations including insect hotels, dead walls, material libraries, standing dead wood, brush piles, dead hedges and log walls. These features reflect the diverse and eclectic habitat needs of a wide array of creatures. Invertebrates, including beneficial insects and pollinators, use plant stems, holes in dead trees and branches, as well as holes in the ground, to nest or overwinter. Birds and mammals hide in thick tangles of branches and harvest grasses and other fibers to build nests or insulate dens. Amphibians rest in cool moist areas shaded by stones and logs, while reptiles use the hotter sides to warm their bodies.</p> Including a diversity in material shapes, sizes, density and decomposition is important in attracting a wide arrange of life. Also, the eclectic rainbow of colors, masses, voids and weight of the branches is quite beautiful in itself. One of the largest installations in the garden is the Wood Wave, a dead hedge that extends more than 25 feet in length and crests to the height of 6 feet. A dead hedge is a prime example of a structure teeming with inner life. Constructed by stacking, compressing and weaving together sticks, branches and brush, a dead hedge offers a multitude of crevices, holes and hollows which are invaluable for shelter and nesting. The dead hedge also serves as a repository for the organic debris generated in the garden, turning waste into a valuable resource.</p> These gardens are not just about the living plants; they're about creating complex spaces where many different phases of life coexist. It's a symphony of growth, decline and renewal, and structures play a vital role in this ecological dance. As the Wood Wave and its sister structures age, they also evolve. They will decompose with winter snows and break down in the summer heat. They will be tended to, modified, and redesigned as necessary, just as we would do with a garden of living plant material.</p> For their help in bringing these installations into existence I would like to recognize Sonya Anderson, assistant curator of pollinator gardens and Plant Select ®, seasonal gardeners Justin Hobert and Jessica Troy, horticulture volunteers John Feek and Pat Roth, and the intern class of 2023. </p>
Chances are you visited the Gardens to see and learn about beautiful and diverse plants. You’ve come to the right place! A query of our living collections database, BG-BASE, provides a snapshot: Denver Botanic Gardens has 11,154 plant species representing 2,286 genera and 247 families from across the globe. Perhaps you’ve already made the connection that a diverse collection of plants provides habitat, shelter and food for urban wildlife, including birds. The Gardens’ many water features provide a fourth requisite—water. </p> These abundant resources have contributed to the Gardens becoming a hotspot for birds. According to the Cornell University's worldwide </span>eBird citizen science website</strong></a>, the community science tool for reporting birds, the combined location of Denver Botanic Gardens and Cheesman Park is the 20th best place to see birds in all of Denver County in terms of numbers of species. In fact, 153 species have been reported at this location—the first report to be documented on eBird was a golden eagle in 1981! While it is unlikely you will encounter a golden eagle during your visit, a host of other birds can be seen and heard daily, and a beautiful fall day at the Gardens is no exception. This walking tour invites you to look and listen for birds while you also enjoy the plants and their fall colors. </p> Begin your tour at Shady Lane </strong>and scan the row of crabapple trees (Malus</em> spp.) on the south side of the sidewalk. Known for showy flowers in spring, these trees provide a fall feast for frugivorous birds (birds who specialize in eating fruit) including American robins and cedar waxwings. The latter is a treat to see—overall buff brown and gray, this species sports a head crest, black facemask, scarlet accents on wing feathers and tail feathers dipped in brilliant yellow. Fun fact: Cedar waxwings can become intoxicated on fermenting fruit after an intense feeding frenzy, so watch for tipsy birds. </li> Stroll down Shady Lane</strong> and look up at the ponderosa pine (Pinus ponderosa</em>) trees behind the crabapples. Black-capped chickadees, which Cornell’s All About Birds refers to as universally cute, are easily spotted in this area. Their presence is often given away by their onomatopoeic call “chick-a-dee-dee” or another call, which to me sounds like “here kitty.” Chickadees are often found in mixed-feeding flocks feasting on insects, berries and pine seeds. Thus, if you spot a chickadee, look for other species including brown creepers, red- and white-breasted nuthatches, and even woodpeckers.</li> Continue down the sidewalk toward the Hive Garden Bistro</strong> and listen for a call that resembles a rusty flute playing a single note at a largo tempo—the song of the Townsend’s solitaire. When you arrive at the Hive </strong>and Monet Pool</strong>, scan for a solitary gray bird with white eye rings perched at the tops of trees, defending their territory. This bird, whose diet includes juniper berries, sings throughout the winter, bringing good cheer to western montane forests and urban neighborhoods alike.</li> Continue to the shrub communities of Dryland Mesa</strong> and Sacred Earth</strong>. Listen for soft twittering calls (helpful hint: Cornell Lab’s Merlin app</strong></a> will help you identify birds by song) and look for flocks of inconspicuous small gray birds. Bushtits often fly single file from one tree or shrub to another, so focus your attention on the junipers (Juniperus</em> spp.), pinyon pines (Pinus edulis</em>) and mountain mahoganies (Cercocarpus</em> spp.) scattered throughout. Social butterflies and perpetually on the move, bushtits can be seen at the Gardens year-round. Due to the multi-layered landscape of native plants in these two gardens, which provide both shelter and an array of food for birds, this is an excellent area to bird. So, linger for a while and listen for the buzzy and whiny calls of spotted towhees and watch for their orange, black and white feathers. Towhees forage for insects in leaf litter (in Colorado often Gambel oak, Quercus gambelii</em>) using a “double-scratching” technique. This maneuver involves hopping backward with two feet, which disturbs the leaf litter and the invertebrates that lie within, bringing them to the surface.</li> </ul> </li> </ul> Hopefully this tour enriched your experience by opening your eyes and ears to some of the many bird species found at the Gardens. Next time you visit, consider downloading the eBird Mobile app</strong></a> and reporting your findings to community science!</p> </p> Photos by Jen Toews</em></p>
Green roofs, also known as vegetated roofs or living roofs, are recognized as a sustainable strategy for urban development. These eco-friendly rooftops offer a multitude of environmental, economic and social benefits, making them a valuable addition to modern cityscapes.</p> Denver implemented its Green Building Ordinance in 2017, requiring adherence to environmentally sustainable standards for commercial and multifamily buildings over 25,000 square feet and for major renovations. These standards include green roofs or roofs with solar panels as an option for compliance. This forward-thinking policy encourages eco-friendly urban development and contributes to Denver's commitment to environmental responsibility, positioning the city as a leader in green building practices.</p> One of the most significant advantages of green roofs is their positive environmental impact. They act as natural insulators, reducing the energy consumption of buildings by moderating indoor temperatures. By absorbing carbon dioxide and filtering the air, vegetation on green roofs contributes to improved air quality and reduced greenhouse gas emissions. They also mitigate the urban heat-island effect, lowering ambient temperatures in densely populated areas. This is particularly important in a city like Denver, where average temperatures are up to five degrees warmer than surrounding rural and suburban areas.</p> Green roofs also play a crucial role in stormwater management. They absorb and clean rainwater, reducing the risk of flooding and preventing pollutants from reaching water bodies. This not only safeguards local water quality but also eases the burden on municipal sewage systems during heavy rainfall events. Adding precious green space also enhances biodiversity, providing habitats for birds, insects and other wildlife where they are typically scarce. The benefits of green roofs extend into the economic realm as well. By reducing energy costs through improved insulation and extending the lifespan of roofing materials, they save money for building owners in the long run, making them a sound investment.</p> Denver Botanic Gardens has been on the cutting-edge of green roof development in Denver. The York Street location has two publicly accessible green roof installations: a smaller green roof above Offshoots Café</a> and Mordecai Children’s Garden</a>, which is over the parking garage. These two green roofs have served as living laboratories, allowing Gardens’ staff and scientific collaborators to improve plant selection for vegetated roofs in Denver’s dry climate and better quantify their environmental benefits. Currently, staff are working to establish vegetation on green roofs through direct seeding, which is more cost-effective and results in more biodiverse plantings than industry-standard plant palettes. Other exciting work in Colorado is being pioneered by researchers at Colorado State University, who are leveraging the combined environmental benefits of green roofs and solar panels to grow crops on rooftops under a protective canopy of energy-generating panels, a practice known as rooftop agrivoltaics.</p> As cities such as Denver evolve, green roofs are becoming an increasingly vital component of a sustainable future. With the continued enthusiasm and backing of governments, cultural and academic institutions, Denver can remain a leader in this field.</p> This article first appeared in Life on Capitol Hill. </em> </p>
